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Roccor R, Wolf ME, Liu J, Eltis LD. The catabolism of ethylene glycol by Rhodococcus jostii RHA1 and its dependence on mycofactocin. Appl Environ Microbiol 2024:e0041624. [PMID: 38837369 DOI: 10.1128/aem.00416-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 05/14/2024] [Indexed: 06/07/2024] Open
Abstract
Ethylene glycol (EG) is a widely used industrial chemical with manifold applications and also generated in the degradation of plastics such as polyethylene terephthalate. Rhodococcus jostii RHA1 (RHA1), a potential biocatalytic chassis, grows on EG. Transcriptomic analyses revealed four clusters of genes potentially involved in EG catabolism: the mad locus, predicted to encode mycofactocin-dependent alcohol degradation, including the catabolism of EG to glycolate; two GCL clusters, predicted to encode glycolate and glyoxylate catabolism; and the mft genes, predicted to specify mycofactocin biosynthesis. Bioinformatic analyses further revealed that the mad and mft genes are widely distributed in mycolic acid-producing bacteria such as RHA1. Neither ΔmadA nor ΔmftC RHA1 mutant strains grew on EG but grew on acetate. In resting cell assays, the ΔmadA mutant depleted glycolaldehyde but not EG from culture media. These results indicate that madA encodes a mycofactocin-dependent alcohol dehydrogenase that initiates EG catabolism. In contrast to some mycobacterial strains, the mad genes did not appear to enable RHA1 to grow on methanol as sole substrate. Finally, a strain of RHA1 adapted to grow ~3× faster on EG contained an overexpressed gene, aldA2, predicted to encode an aldehyde dehydrogenase. When incubated with EG, this strain accumulated lower concentrations of glycolaldehyde than RHA1. Moreover, ecotopically expressed aldA2 increased RHA1's tolerance for EG further suggesting that glycolaldehyde accumulation limits growth of RHA1 on EG. Overall, this study provides insights into the bacterial catabolism of small alcohols and aldehydes and facilitates the engineering of Rhodococcus for the upgrading of plastic waste streams.IMPORTANCEEthylene glycol (EG), a two-carbon (C2) alcohol, is produced in high volumes for use in a wide variety of applications. There is burgeoning interest in understanding and engineering the bacterial catabolism of EG, in part to establish circular economic routes for its use. This study identifies an EG catabolic pathway in Rhodococcus, a genus of bacteria well suited for biocatalysis. This pathway is responsible for the catabolism of methanol, a C1 feedstock, in related bacteria. Finally, we describe strategies to increase the rate of degradation of EG by increasing the transformation of glycolaldehyde, a toxic metabolic intermediate. This work advances the development of biocatalytic strategies to transform C2 feedstocks.
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Affiliation(s)
- Raphael Roccor
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Megan E Wolf
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jie Liu
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Lindsay D Eltis
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
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Ferrari E, Di Benedetto G, Firrincieli A, Presentato A, Frascari D, Cappelletti M. Unravelling the role of the group 6 soluble di-iron monooxygenase (SDIMO) SmoABCD in alkane metabolism and chlorinated alkane degradation. Microb Biotechnol 2024; 17:e14453. [PMID: 38683670 PMCID: PMC11057499 DOI: 10.1111/1751-7915.14453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 03/07/2024] [Accepted: 03/09/2024] [Indexed: 05/02/2024] Open
Abstract
Soluble di-iron monooxygenases (SDIMOs) are multi-component enzymes catalysing the oxidation of various substrates. These enzymes are characterized by high sequence and functional diversity that is still not well understood despite their key role in biotechnological processes including contaminant biodegradation. In this study, we analysed a mutant of Rhodoccocus aetherivorans BCP1 (BCP1-2.10) characterized by a transposon insertion in the gene smoA encoding the alpha subunit of the plasmid-located SDIMO SmoABCD. The mutant BCP1-2.10 showed a reduced capacity to grow on propane, lost the ability to grow on butane, pentane and n-hexane and was heavily impaired in the capacity to degrade chloroform and trichloroethane. The expression of the additional SDIMO prmABCD in BCP1-2.10 probably allowed the mutant to partially grow on propane and to degrade it, to some extent, together with the other short-chain n-alkanes. The complementation of the mutant, conducted by introducing smoABCD in the genome as a single copy under a constitutive promoter or within a plasmid under a thiostreptone-inducible promoter, allowed the recovery of the alkanotrophic phenotype as well as the capacity to degrade chlorinated n-alkanes. The heterologous expression of smoABCD allowed a non-alkanotrophic Rhodococcus strain to grow on pentane and n-hexane when the gene cluster was introduced together with the downstream genes encoding alcohol and aldehyde dehydrogenases and a GroEL chaperon. BCP1 smoA gene was shown to belong to the group 6 SDIMOs, which is a rare group of monooxygenases mostly present in Mycobacterium genus and in a few Rhodococcus strains. SmoABCD originally evolved in Mycobacterium and was then acquired by Rhodococcus through horizontal gene transfer events. This work extends the knowledge of the biotechnologically relevant SDIMOs by providing functional and evolutionary insights into a group 6 SDIMO in Rhodococcus and demonstrating its key role in the metabolism of short-chain alkanes and degradation of chlorinated n-alkanes.
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Affiliation(s)
- Eleonora Ferrari
- Department of Pharmacy and Biotechnology (FaBit)University of BolognaBolognaItaly
| | - Giulio Di Benedetto
- Department of Pharmacy and Biotechnology (FaBit)University of BolognaBolognaItaly
| | - Andrea Firrincieli
- Department for Innovation in Biological, Agro‐Food and Forest SystemsUniversity of TusciaViterboItaly
| | - Alessandro Presentato
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF)University of PalermoPalermoItaly
| | - Dario Frascari
- Department of Civil, Chemical, Environmental and Materials Engineering (DICAM)University of BolognaBolognaItaly
| | - Martina Cappelletti
- Department of Pharmacy and Biotechnology (FaBit)University of BolognaBolognaItaly
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Yang SNN, Haritos V, Kertesz MA, Coleman NV. A novel soluble di-iron monooxygenase from the soil bacterium Solimonas soli. Environ Microbiol 2024; 26:e16567. [PMID: 38233213 DOI: 10.1111/1462-2920.16567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Accepted: 12/12/2023] [Indexed: 01/19/2024]
Abstract
Soluble di-iron monooxygenase (SDIMO) enzymes enable insertion of oxygen into diverse substrates and play significant roles in biogeochemistry, bioremediation and biocatalysis. An unusual SDIMO was detected in an earlier study in the genome of the soil organism Solimonas soli, but was not characterized. Here, we show that the S. soli SDIMO is part of a new clade, which we define as 'Group 7'; these share a conserved gene organization with alkene monooxygenases but have only low amino acid identity. The S. soli genes (named zmoABCD) could be functionally expressed in Pseudomonas putida KT2440 but not in Escherichia coli TOP10. The recombinants made epoxides from C2 C8 alkenes, preferring small linear alkenes (e.g. propene), but also epoxidating branched, carboxylated and chlorinated substrates. Enzymatic epoxidation of acrylic acid was observed for the first time. ZmoABCD oxidised the organochlorine pollutants vinyl chloride (VC) and cis-1,2-dichloroethene (cDCE), with the release of inorganic chloride from VC but not cDCE. The original host bacterium S. soli could not grow on any alkenes tested but grew well on phenol and n-octane. Further work is needed to link ZmoABCD and the other Group 7 SDIMOs to specific physiological and ecological roles.
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Affiliation(s)
- Sui Nin Nicholas Yang
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Victoria Haritos
- Department of Chemical and Biological Engineering, Monash University, Melbourne, Victoria, Australia
| | - Michael A Kertesz
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Nicholas V Coleman
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
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Wang S, Yun Y, Tian X, Su Z, Liao Z, Li G, Ma T. HMDB: A curated database of genes involved in hydrocarbon monooxygenation reaction with homologous genes as background. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132397. [PMID: 37639797 DOI: 10.1016/j.jhazmat.2023.132397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/10/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023]
Abstract
The investigation of hydrocarbon degradation potential of environmental microorganisms is an important research topic, whether for the global carbon cycle or oil pollution remediation. Under aerobic conditions, the microorganisms employ a range of monooxygenases to use hydrocarbons substrates as a source of carbon and energy. With the explosion of sequencing data, mining genes in genomes or metagenomes has become computationally expensive and time-consuming. We proposed the HMDB, which is a professional gene database of hydrocarbon monooxygenases. HMDB contains 38 genes, which encode 11 monooxygenases responsible for the hydroxylation of 8 hydrocarbons. To reduce false positives, the strategy of using homologous genes as background noise was applied for HMDB. We added 10,095 gene sequences of homologous enzymes which took non-hydrocarbons as substrates to HMDB. The classic BLAST method and best-hit strategy were recommended for HMDB usage, but not limited. The performance of HMDB was validated using 264,402 prokaryote genomes from RefSeq and 51 metagenomes from SRA. The results showed that HMDB database had high sensitivity and low false positive rate. We release the HMDB database here, hoping to speed up the process for investigation of hydrocarbon monooxygenases in massive metagenomic data. HMDB is freely available at http://www.orgene.net/HMDB/.
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Affiliation(s)
- Shaojing Wang
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yuan Yun
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xuefeng Tian
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Zhaoying Su
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Zitong Liao
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Guoqiang Li
- College of Life Sciences, Nankai University, Tianjin 300071, China.
| | - Ting Ma
- College of Life Sciences, Nankai University, Tianjin 300071, China.
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Fenibo EO, Selvarajan R, Abia ALK, Matambo T. Medium-chain alkane biodegradation and its link to some unifying attributes of alkB genes diversity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162951. [PMID: 36948313 DOI: 10.1016/j.scitotenv.2023.162951] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 05/06/2023]
Abstract
Hydrocarbon footprints in the environment, via biosynthesis, natural seepage, anthropogenic activities and accidents, affect the ecosystem and induce a shift in the healthy biogeochemical equilibrium that drives needed ecological services. In addition, these imbalances cause human diseases and reduce animal and microorganism diversity. Microbial bioremediation, which capitalizes on functional genes, is a sustainable mitigation option for cleaning hydrocarbon-impacted environments. This review focuses on the bacterial alkB functional gene, which codes for a non-heme di‑iron monooxygenase (AlkB) with a di‑iron active site that catalyzes C8-C16 medium-chain alkane metabolism. These enzymes are ubiquitous and share common attributes such as being controlled by global transcriptional regulators, being a component of most super hydrocarbon degraders, and their distributions linked to horizontal gene transfer (HGT) events. The phylogenetic approach used in the HGT detection suggests that AlkB tree topology clusters bacteria functionally and that a preferential gradient dictates gene distribution. The alkB gene also acts as a biomarker for bioremediation, although it is found in pristine environments and absent in some hydrocarbon degraders. For instance, a quantitative molecular method has failed to link alkB copy number to contamination concentration levels. This limitation may be due to AlkB homologues, which have other functions besides n-alkane assimilation. Thus, this review, which focuses on Pseudomonas putida GPo1 alkB, shows that AlkB proteins are diverse but have some unifying trends around hydrocarbon-degrading bacteria; it is erroneous to rely on alkB detection alone as a monitoring parameter for hydrocarbon degradation, alkB gene distribution are preferentially distributed among bacteria, and the plausible explanation for AlkB affiliation to broad-spectrum metabolism of hydrocarbons in super-degraders hitherto reported. Overall, this review provides a broad perspective of the ecology of alkB-carrying bacteria and their directed biodegradation pathways.
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Affiliation(s)
- Emmanuel Oliver Fenibo
- World Bank Africa Centre of Excellence, Centre for Oilfield Chemical Research, University of Port Harcourt, Port Harcourt 500272, Nigeria
| | - Ramganesh Selvarajan
- Laboratory of Extraterrestrial Ocean Systems (LEOS), Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China; Department of Environmental Science, University of South Africa, Florida Campus, 1710, South Africa
| | - Akebe Luther King Abia
- Department of Environmental Science, University of South Africa, Florida Campus, 1710, South Africa; Environmental Research Foundation, Westville 3630, South Africa
| | - Tonderayi Matambo
- Institute for the Development of Energy for African Sustainability, University of South Africa, Roodepoort 1709, South Africa.
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Frantsuzova E, Bogun A, Solomentsev V, Vetrova A, Streletskii R, Solyanikova I, Delegan Y. Whole Genome Analysis and Assessment of the Metabolic Potential of Gordonia rubripertincta Strain 112, a Degrader of Aromatic and Aliphatic Compounds. BIOLOGY 2023; 12:biology12050721. [PMID: 37237534 DOI: 10.3390/biology12050721] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/11/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023]
Abstract
The application of Gordonia strains in biotechnologies of environmental purification as degraders of pollutants of different chemical structures is an interesting research topic. The strain Gordonia rubripertincta 112 (IEGM112) is capable of utilizing diesel fuel, alkanes, and aromatic compounds. The aim of this work was to study the potential of G. rubripertincta 112 as a degrader of aromatic and aliphatic compounds and analyze its complete genome in comparison with other known G. rubripertincta strains. The genome had a total length of 5.28 Mb and contained 4861 genes in total, of which 4799 were coding sequences (CDS). The genome contained 62 RNA genes in total, of which 50 were tRNAs, three were ncRNAs, and nine were rRNAs. The strain bears plasmid elements with a total length of 189,570 nucleotides (plasmid p1517). The strain can utilize 10.79 ± 1.17% of hexadecane and 16.14 ± 0.16% of decane over 3 days of cultivation. In the genome of the strain, we have found metabolic pathways of alkane (cytochrome P450 hydroxylases) and catechol (ortho- and meta-pathways) degradation. These results will help us to further approach the fundamental study of the processes occurring in the strain cells and to enrich our knowledge of the catabolic capabilities of G. rubripertincta.
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Affiliation(s)
- Ekaterina Frantsuzova
- Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences" (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia
| | - Alexander Bogun
- Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences" (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia
- State Research Center for Applied Microbiology and Biotechnology, 142279 Obolensk, Moscow Region, Russia
| | - Viktor Solomentsev
- Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences" (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia
- State Research Center for Applied Microbiology and Biotechnology, 142279 Obolensk, Moscow Region, Russia
| | - Anna Vetrova
- Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences" (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia
| | - Rostislav Streletskii
- Laboratory of Ecological Soil Science, Faculty of Soil Science, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Inna Solyanikova
- Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences" (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia
- Regional Microbiological Center, Belgorod State University, 308015 Belgorod, Russia
| | - Yanina Delegan
- Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences" (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia
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Volmer JG, Soo RM, Evans PN, Hoedt EC, Astorga Alsina AL, Woodcroft BJ, Tyson GW, Hugenholtz P, Morrison M. Isolation and characterisation of novel Methanocorpusculum species indicates the genus is ancestrally host-associated. BMC Biol 2023; 21:59. [PMID: 36949471 PMCID: PMC10035134 DOI: 10.1186/s12915-023-01524-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 01/20/2023] [Indexed: 03/24/2023] Open
Abstract
BACKGROUND With an increasing interest in the manipulation of methane produced from livestock cultivation, the microbiome of Australian marsupials provides a unique ecological and evolutionary comparison with 'low-methane' emitters. Previously, marsupial species were shown to be enriched for novel lineages of Methanocorpusculum, as well as Methanobrevibacter, Methanosphaera, and Methanomassiliicoccales. Despite sporadic reports of Methanocorpusculum from stool samples of various animal species, there remains little information on the impacts of these methanogens on their hosts. RESULTS Here, we characterise novel host-associated species of Methanocorpusculum, to explore unique host-specific genetic factors and their associated metabolic potential. We performed comparative analyses on 176 Methanocorpusculum genomes comprising 130 metagenome-assembled genomes (MAGs) recovered from 20 public animal metagenome datasets and 35 other publicly available Methanocorpusculum MAGs and isolate genomes of host-associated and environmental origin. Nine MAGs were also produced from faecal metagenomes of the common wombat (Vombatus ursinus) and mahogany glider (Petaurus gracilis), along with the cultivation of one axenic isolate from each respective animal; M. vombati (sp. nov.) and M. petauri (sp. nov.). CONCLUSIONS Through our analyses, we substantially expand the available genetic information for this genus by describing the phenotypic and genetic characteristics of 23 host-associated species of Methanocorpusculum. These lineages display differential enrichment of genes associated with methanogenesis, amino acid biosynthesis, transport system proteins, phosphonate metabolism, and carbohydrate-active enzymes. These results provide insights into the differential genetic and functional adaptations of these novel host-associated species of Methanocorpusculum and suggest that this genus is ancestrally host-associated.
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Affiliation(s)
- James G Volmer
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, 4102, Australia
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, 4102, Australia
| | - Rochelle M Soo
- School of Chemistry and Molecular Biosciences and Australian Centre for Ecogenomics, University of Queensland, Saint Lucia, 4072, Australia
| | - Paul N Evans
- School of Chemistry and Molecular Biosciences and Australian Centre for Ecogenomics, University of Queensland, Saint Lucia, 4072, Australia
| | - Emily C Hoedt
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, 4102, Australia
- Current Address: NHMRC Centre of Research Excellence (CRE) in Digestive Health, Hunter Medical Research Institute (HMRI), Newcastle, NSW, Australia
| | - Ana L Astorga Alsina
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, 4102, Australia
| | - Benjamin J Woodcroft
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, 4102, Australia
| | - Gene W Tyson
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, 4102, Australia
| | - Philip Hugenholtz
- School of Chemistry and Molecular Biosciences and Australian Centre for Ecogenomics, University of Queensland, Saint Lucia, 4072, Australia
| | - Mark Morrison
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, 4102, Australia.
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Wang M, Ding M, Yuan Y. Bioengineering for the Microbial Degradation of Petroleum Hydrocarbon Contaminants. Bioengineering (Basel) 2023; 10:bioengineering10030347. [PMID: 36978738 PMCID: PMC10045523 DOI: 10.3390/bioengineering10030347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/02/2023] [Accepted: 03/04/2023] [Indexed: 03/18/2023] Open
Abstract
Petroleum hydrocarbons are relatively recalcitrant compounds, and as contaminants, they are one of the most serious environmental problems. n-Alkanes are important constituents of petroleum hydrocarbons. Advances in synthetic biology and metabolic engineering strategies have made n-alkane biodegradation more designable and maneuverable for solving environmental pollution problems. In the microbial degradation of n-alkanes, more and more degradation pathways, related genes, microbes, and alkane hydroxylases have been discovered, which provide a theoretical basis for the further construction of degrading strains and microbial communities. In this review, the current advances in the microbial degradation of n-alkanes under aerobic condition are summarized in four aspects, including the biodegradation pathways and related genes, alkane hydroxylases, engineered microbial chassis, and microbial community. Especially, the microbial communities of “Alkane-degrader and Alkane-degrader” and “Alkane-degrader and Helper” provide new ideas for the degradation of petroleum hydrocarbons. Surfactant producers and nitrogen providers as a “Helper” are discussed in depth. This review will be helpful to further achieve bioremediation of oil-polluted environments rapidly.
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Affiliation(s)
- Minzhen Wang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Mingzhu Ding
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Correspondence:
| | - Yingjin Yuan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
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Identification of active gaseous-alkane degraders at natural gas seeps. THE ISME JOURNAL 2022; 16:1705-1716. [PMID: 35319019 PMCID: PMC9213486 DOI: 10.1038/s41396-022-01211-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/30/2022] [Accepted: 02/04/2022] [Indexed: 11/29/2022]
Abstract
Natural gas seeps release significant amounts of methane and other gases including ethane and propane contributing to global climate change. In this study, bacterial actively consuming short-chain alkanes were identified by cultivation, whole-genome sequencing, and stable-isotope probing (SIP)-metagenomics using 13C-propane and 13C-ethane from two different natural gas seeps, Pipe Creek and Andreiasu Everlasting Fire. Nearly 100 metagenome-assembled genomes (MAGs) (completeness 70–99%) were recovered from both sites. Among these, 16 MAGs had genes encoding the soluble di-iron monooxygenase (SDIMO). The MAGs were affiliated to Actinobacteria (two MAGs), Alphaproteobacteria (ten MAGs), and Gammaproteobacteria (four MAGs). Additionally, three gaseous-alkane degraders were isolated in pure culture, all of which could grow on ethane, propane, and butane and possessed SDIMO-related genes. Two Rhodoblastus strains (PC2 and PC3) were from Pipe Creek and a Mycolicibacterium strain (ANDR5) from Andreiasu. Strains PC2 and PC3 encoded putative butane monooxygenases (MOs) and strain ANDR5 contained a propane MO. Mycolicibacterium strain ANDR5 and MAG19a, highly abundant in incubations with 13C-ethane, share an amino acid identity (AAI) of 99.3%. We show using a combination of enrichment and isolation, and cultivation-independent techniques, that these natural gas seeps contain a diverse community of active bacteria oxidising gaseous-alkanes, which play an important role in biogeochemical cycling of natural gas.
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Degradation of 1,4-dioxane by Newly Isolated Acinetobacter sp. M21 with Molasses as the Auxiliary Substrate. BIOTECHNOL BIOPROC E 2022. [DOI: 10.1007/s12257-021-0212-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Mahor D, Cong Z, Weissenborn MJ, Hollmann F, Zhang W. Valorization of Small Alkanes by Biocatalytic Oxyfunctionalization. CHEMSUSCHEM 2022; 15:e202101116. [PMID: 34288540 DOI: 10.1002/cssc.202101116] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/18/2021] [Indexed: 06/13/2023]
Abstract
The oxidation of alkanes into valuable chemical products is a vital reaction in organic synthesis. This reaction, however, is challenging, owing to the inertness of C-H bonds. Transition metal catalysts for C-H functionalization are frequently explored. Despite chemical alternatives, nature has also evolved powerful oxidative enzymes (e. g., methane monooxygenases, cytochrome P450 oxygenases, peroxygenases) that are capable of transforming C-H bonds under very mild conditions, with only the use of molecular oxygen or hydrogen peroxide as electron acceptors. Although progress in alkane oxidation has been reviewed extensively, little attention has been paid to small alkane oxidation. The latter holds great potential for the manufacture of chemicals. This Minireview provides a concise overview of the most relevant enzyme classes capable of small alkanes (C<6 ) oxyfunctionalization, describes the essentials of the catalytic mechanisms, and critically outlines the current state-of-the-art in preparative applications.
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Affiliation(s)
- Durga Mahor
- National Innovation Center for Synthetic Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
- Indian Institute of Science Education and Research Berhampur, Odisha, 760010, India
| | - Zhiqi Cong
- CAS Key Laboratory of Biofuels and Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences, Qingdao, Shandong, 266101, P. R. China
| | - Martin J Weissenborn
- Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120 Halle, Saale), Germany
| | - Frank Hollmann
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ, Delft, The Netherlands
| | - Wuyuan Zhang
- National Innovation Center for Synthetic Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
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12
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Moratti CF, Scott C, Coleman NV. Synthetic Biology Approaches to Hydrocarbon Biosensors: A Review. Front Bioeng Biotechnol 2022; 9:804234. [PMID: 35083206 PMCID: PMC8784404 DOI: 10.3389/fbioe.2021.804234] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/09/2021] [Indexed: 12/12/2022] Open
Abstract
Monooxygenases are a class of enzymes that facilitate the bacterial degradation of alkanes and alkenes. The regulatory components associated with monooxygenases are nature's own hydrocarbon sensors, and once functionally characterised, these components can be used to create rapid, inexpensive and sensitive biosensors for use in applications such as bioremediation and metabolic engineering. Many bacterial monooxygenases have been identified, yet the regulation of only a few of these have been investigated in detail. A wealth of genetic and functional diversity of regulatory enzymes and promoter elements still remains unexplored and unexploited, both in published genome sequences and in yet-to-be-cultured bacteria. In this review we examine in detail the current state of research on monooxygenase gene regulation, and on the development of transcription-factor-based microbial biosensors for detection of alkanes and alkenes. A new framework for the systematic characterisation of the underlying genetic components and for further development of biosensors is presented, and we identify focus areas that should be targeted to enable progression of more biosensor candidates to commercialisation and deployment in industry and in the environment.
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Affiliation(s)
- Claudia F. Moratti
- School of Life and Environmental Science, Faculty of Science, University of Sydney, Sydney, NSW, Australia
- CSIRO Synthetic Biology Future Science Platform, Canberra, ACT, Australia
| | - Colin Scott
- CSIRO Synthetic Biology Future Science Platform, Canberra, ACT, Australia
| | - Nicholas V. Coleman
- School of Life and Environmental Science, Faculty of Science, University of Sydney, Sydney, NSW, Australia
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13
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Gibson L, Crombie AT, McNamara NP, Murrell JC. Isoprene-degrading bacteria associated with the phyllosphere of Salix fragilis, a high isoprene-emitting willow of the Northern Hemisphere. ENVIRONMENTAL MICROBIOME 2021; 16:17. [PMID: 34446108 PMCID: PMC8394569 DOI: 10.1186/s40793-021-00386-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/12/2021] [Indexed: 05/13/2023]
Abstract
BACKGROUND Isoprene accounts for about half of total biogenic volatile organic compound emissions globally, and as a climate active gas it plays a significant and varied role in atmospheric chemistry. Terrestrial plants are the largest source of isoprene, with willow (Salix) making up one of the most active groups of isoprene producing trees. Bacteria act as a biological sink for isoprene and those bacteria associated with high isoprene-emitting trees may provide further insight into its biodegradation. RESULTS A DNA-SIP experiment incubating willow (Salix fragilis) leaves with 13C-labelled isoprene revealed an abundance of Comamonadaceae, Methylobacterium, Mycobacterium and Polaromonas in the isoprene degrading community when analysed by 16S rRNA gene amplicon sequencing. Metagenomic analysis of 13C-enriched samples confirmed the abundance of Comamonadaceae, Acidovorax, Polaromonas, Variovorax and Ramlibacter. Mycobacterium and Methylobacterium were also identified after metagenomic analysis and a Mycobacterium metagenome-assembled genome (MAG) was recovered. This contained two complete isoprene degradation metabolic gene clusters, along with a propane monooxygenase gene cluster. Analysis of the abundance of the alpha subunit of the isoprene monooxygenase, isoA, in unenriched DNA samples revealed that isoprene degraders associated with willow leaves are abundant, making up nearly 0.2% of the natural bacterial community. CONCLUSIONS Analysis of the isoprene degrading community associated with willow leaves using DNA-SIP and focused metagenomics techniques enabled recovery of the genome of an active isoprene-degrading Mycobacterium species and provided valuable insight into bacteria involved in degradation of isoprene on the leaves of a key species of isoprene-emitting tree in the northern hemisphere.
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Affiliation(s)
- Lisa Gibson
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Andrew T Crombie
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Niall P McNamara
- Centre of Ecology and Hydrology, Lancaster University, Bailrigg, Lancaster, LA1 4AP, UK
| | - J Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
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14
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Farhan Ul Haque M, Xu HJ, Murrell JC, Crombie A. Facultative methanotrophs - diversity, genetics, molecular ecology and biotechnological potential: a mini-review. MICROBIOLOGY (READING, ENGLAND) 2020; 166:894-908. [PMID: 33085587 PMCID: PMC7660913 DOI: 10.1099/mic.0.000977] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 09/20/2020] [Indexed: 12/18/2022]
Abstract
Methane-oxidizing bacteria (methanotrophs) play a vital role in reducing atmospheric methane emissions, and hence mitigating their potent global warming effects. A significant proportion of the methane released is thermogenic natural gas, containing associated short-chain alkanes as well as methane. It was one hundred years following the description of methanotrophs that facultative strains were discovered and validly described. These can use some multi-carbon compounds in addition to methane, often small organic acids, such as acetate, or ethanol, although Methylocella strains can also use short-chain alkanes, presumably deriving a competitive advantage from this metabolic versatility. Here, we review the diversity and molecular ecology of facultative methanotrophs. We discuss the genetic potential of the known strains and outline the consequent benefits they may obtain. Finally, we review the biotechnological promise of these fascinating microbes.
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Affiliation(s)
| | - Hui-Juan Xu
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
- Present address: Joint Institute for Environmental Research & Education, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, PR China
| | - J. Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Andrew Crombie
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
- Present address: School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
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15
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Reyes-Sánchez FJ, Páez-Lerma JB, Rojas-Contreras JA, López-Miranda J, Soto-Cruz NÓ, Reinhart-Kirchmayr M. Study of the Enzymatic Capacity of Kluyveromyces marxianus for the Synthesis of Esters. J Mol Microbiol Biotechnol 2020; 29:1-9. [PMID: 32325454 DOI: 10.1159/000507551] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 03/24/2020] [Indexed: 11/19/2022] Open
Abstract
Recently, biotechnological opportunities have been found in non-Saccharomyces yeasts because they possess metabolic characteristics that lead to the production of compounds of interest. It has been observed that Kluyveromyces marxianus has a great potential in the production of esters, which are aromatic compounds of industrial importance. The genetic bases that govern the synthesis of esters include a large group of enzymes, among which the most important are alcohol acetyl transferases (AATases) and esterases (AEATases), and it is known that some are present in K. marxianus, because it has genetic characteristics like S. cerevisiae. It also has a physiology suitable for biotechnological use since it is the eukaryotic microorganism with the fastest growth rate and has a wide range of thermotolerance with respect to other yeasts. In this work, the enzymatic background of K. marxianus involved in the synthesis of esters is analyzed, based on the sequences reported in the NCBI database.
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Affiliation(s)
| | | | | | - Javier López-Miranda
- Chemistry and Biochemistry, TECNM/Instituto Tecnológico de Durango, Durango, Mexico
| | | | - Manuel Reinhart-Kirchmayr
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco A.C., Guadalajara, Mexico
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16
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Gaytán I, Sánchez-Reyes A, Burelo M, Vargas-Suárez M, Liachko I, Press M, Sullivan S, Cruz-Gómez MJ, Loza-Tavera H. Degradation of Recalcitrant Polyurethane and Xenobiotic Additives by a Selected Landfill Microbial Community and Its Biodegradative Potential Revealed by Proximity Ligation-Based Metagenomic Analysis. Front Microbiol 2020; 10:2986. [PMID: 32038514 PMCID: PMC6987047 DOI: 10.3389/fmicb.2019.02986] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/10/2019] [Indexed: 11/30/2022] Open
Abstract
Polyurethanes (PU) are the sixth most produced plastics with around 18-million tons in 2016, but since they are not recyclable, they are burned or landfilled, generating damage to human health and ecosystems. To elucidate the mechanisms that landfill microbial communities perform to attack recalcitrant PU plastics, we studied the degradative activity of a mixed microbial culture, selected from a municipal landfill by its capability to grow in a water PU dispersion (WPUD) as the only carbon source, as a model for the BP8 landfill microbial community. The WPUD contains a polyether-polyurethane-acrylate (PE-PU-A) copolymer and xenobiotic additives (N-methylpyrrolidone, isopropanol and glycol ethers). To identify the changes that the BP8 microbial community culture generates to the WPUD additives and copolymer, we performed chemical and physical analyses of the biodegradation process during 25 days of cultivation. These analyses included Nuclear magnetic resonance, Fourier transform infrared spectroscopy, Thermogravimetry, Differential scanning calorimetry, Gel permeation chromatography, and Gas chromatography coupled to mass spectrometry techniques. Moreover, for revealing the BP8 community structure and its genetically encoded potential biodegradative capability we also performed a proximity ligation-based metagenomic analysis. The additives present in the WPUD were consumed early whereas the copolymer was cleaved throughout the 25-days of incubation. The analysis of the biodegradation process and the identified biodegradation products showed that BP8 cleaves esters, C-C, and the recalcitrant aromatic urethanes and ether groups by hydrolytic and oxidative mechanisms, both in the soft and the hard segments of the copolymer. The proximity ligation-based metagenomic analysis allowed the reconstruction of five genomes, three of them from novel species. In the metagenome, genes encoding known enzymes, and putative enzymes and metabolic pathways accounting for the biodegradative activity of the BP8 community over the additives and PE-PU-A copolymer were identified. This is the first study revealing the genetically encoded potential biodegradative capability of a microbial community selected from a landfill, that thrives within a WPUD system and shows potential for bioremediation of polyurethane- and xenobiotic additives-contamitated sites.
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Affiliation(s)
- Itzel Gaytán
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ayixon Sánchez-Reyes
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Manuel Burelo
- Departamento de Química Analítica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Martín Vargas-Suárez
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | | | | | - M. Javier Cruz-Gómez
- Departamento de Ingeniería Química, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Herminia Loza-Tavera
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
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17
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Hatzinger PB, Lippincott DR. Field demonstration of N-Nitrosodimethylamine (NDMA) treatment in groundwater using propane biosparging. WATER RESEARCH 2019; 164:114923. [PMID: 31400594 DOI: 10.1016/j.watres.2019.114923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/11/2019] [Accepted: 07/27/2019] [Indexed: 06/10/2023]
Abstract
N-Nitrosodimethylamine (NDMA) is found in groundwater and drinking water from industrial, agricultural, water treatment, and military/aerospace sources, and it must often be treated to part-per-trillion (ng/L) concentrations. The most effective remedial technology for NDMA in groundwater is pump-and-treat with ultraviolet irradiation (UV), but this approach is expensive because it requires ex situ infrastructure and high energy input. The objective of this project was to evaluate an in situ biological treatment approach for NDMA. Previous laboratory studies have revealed that propane-oxidizing bacteria are capable of biodegrading NDMA from μg/L to low ng/L concentrations (Fournier et al., 2009; Webster et al., 2013). During this field study, air and propane gas were sparged into an NDMA-contaminated aquifer for more than 1 year. Groundwater samples were collected throughout the study from a series of monitoring wells within, downgradient, and sidegradient of the zone of influence of the biosparge system. Over the course of the study, NDMA concentrations declined by 99.7% to >99.9% in the four monitoring wells within the zone of influence of the biosparge system, reaching low ng/L concentrations whereas the control well declined by only 14%. Pseudo first-order degradation rate constants for NDMA in system monitoring wells ranged from ∼0.019 day -1 to 0.037 day -1 equating to half-lives ranging from 19 to 36 days. Native propanotrophs increased by more than one order of magnitude in the propane-impacted wells but not in the control well. The field data show for the first time that propane biosparging can be an effective in situ approach to reduce the concentrations of NDMA in a groundwater to ng/L concentrations.
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Affiliation(s)
- Paul B Hatzinger
- Biotechnology Development and Applications Group, Aptim Federal Services, Lawrenceville, NJ, United States.
| | - David R Lippincott
- Biotechnology Development and Applications Group, Aptim Federal Services, Lawrenceville, NJ, United States
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18
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Garrido-Sanz D, Redondo-Nieto M, Guirado M, Pindado Jiménez O, Millán R, Martin M, Rivilla R. Metagenomic Insights into the Bacterial Functions of a Diesel-Degrading Consortium for the Rhizoremediation of Diesel-Polluted Soil. Genes (Basel) 2019; 10:E456. [PMID: 31207997 PMCID: PMC6627497 DOI: 10.3390/genes10060456] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/07/2019] [Accepted: 06/07/2019] [Indexed: 02/05/2023] Open
Abstract
Diesel is a complex pollutant composed of a mixture of aliphatic and aromatic hydrocarbons. Because of this complexity, diesel bioremediation requires multiple microorganisms, which harbor the catabolic pathways to degrade the mixture. By enrichment cultivation of rhizospheric soil from a diesel-polluted site, we have isolated a bacterial consortium that can grow aerobically with diesel and different alkanes and polycyclic aromatic hydrocarbons (PAHs) as the sole carbon and energy source. Microbiome diversity analyses based on 16S rRNA gene showed that the diesel-degrading consortium consists of 76 amplicon sequence variants (ASVs) and it is dominated by Pseudomonas, Aquabacterium, Chryseobacterium, and Sphingomonadaceae. Changes in microbiome composition were observed when growing on specific hydrocarbons, reflecting that different populations degrade different hydrocarbons. Shotgun metagenome sequence analysis of the consortium growing on diesel has identified redundant genes encoding enzymes implicated in the initial oxidation of alkanes (AlkB, LadA, CYP450) and a variety of hydroxylating and ring-cleavage dioxygenases involved in aromatic and polyaromatic hydrocarbon degradation. The phylogenetic assignment of these enzymes to specific genera allowed us to model the role of specific populations in the diesel-degrading consortium. Rhizoremediation of diesel-polluted soil microcosms using the consortium, resulted in an important enhancement in the reduction of total petroleum hydrocarbons (TPHs), making it suited for rhizoremediation applications.
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Affiliation(s)
- Daniel Garrido-Sanz
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin 2, 28049 Madrid, Spain.
| | - Miguel Redondo-Nieto
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin 2, 28049 Madrid, Spain.
| | - María Guirado
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Avenida Complutense 40, 28040 Madrid, Spain.
| | - Oscar Pindado Jiménez
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Avenida Complutense 40, 28040 Madrid, Spain.
| | - Rocío Millán
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Avenida Complutense 40, 28040 Madrid, Spain.
| | - Marta Martin
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin 2, 28049 Madrid, Spain.
| | - Rafael Rivilla
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin 2, 28049 Madrid, Spain.
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19
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Osborne CD, Haritos VS. Beneath the surface: Evolution of methane activity in the bacterial multicomponent monooxygenases. Mol Phylogenet Evol 2019; 139:106527. [PMID: 31173882 DOI: 10.1016/j.ympev.2019.106527] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/03/2019] [Accepted: 06/03/2019] [Indexed: 02/09/2023]
Abstract
The bacterial multicomponent monooxygenase (BMM) family has evolved to oxidise a wide array of hydrocarbon substrates of importance to environmental emissions and biotechnology: foremost amongst these is methane, which requires among the most powerful oxidant in biology to activate. To understand how the BMM evolved methane oxidation activity, we investigated the changes in the enzyme family at different levels: operonic, phylogenetic analysis of the catalytic hydroxylase, subunit or folding factor presence, and sequence-function analysis across the entirety of the BMM phylogeny. Our results show that the BMM evolution of new activities was enabled by incremental increases in oxidative power of the active site, and these occur in multiple branches of the hydroxylase phylogenetic tree. While the hydroxylase primary sequence changes that resulted in increased oxidative power of the enzyme appear to be minor, the principle evolutionary advances enabling methane activity occurred in the other components of the BMM complex and in the recruitment of stability proteins. We propose that enzyme assembly and stabilization factors have independently-evolved multiple times in the BMM family to support enzymes that oxidise increasingly difficult substrates. Herein, we show an important example of evolution of catalytic function where modifications to the active site and substrate accessibility, which are the usual focus of enzyme evolution, are overshadowed by broader scale changes to structural stabilization and non-catalytic unit development. Retracing macroscale changes during enzyme evolution, as demonstrated here, should find ready application to other enzyme systems and in protein design.
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Affiliation(s)
- Craig D Osborne
- Department of Chemical Engineering, Monash University, Wellington Road, Clayton 3800, Australia
| | - Victoria S Haritos
- Department of Chemical Engineering, Monash University, Wellington Road, Clayton 3800, Australia.
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20
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Biological conversion of propane to 2-propanol using group I and II methanotrophs as biocatalysts. ACTA ACUST UNITED AC 2019; 46:675-685. [DOI: 10.1007/s10295-019-02141-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 01/21/2019] [Indexed: 12/19/2022]
Abstract
Abstract
Propane is the main component of liquefied petroleum gas and is derived from crude oil processing. Methanotrophic bacteria can convert various alkanes using methane monooxygenase enzyme to primary alcohols. These are further oxidized to various aldehydes by alcohol dehydrogenases or methanol dehydrogenases. In this study, 2-propanol was produced from propane using the whole cells of Methylosinus trichosporium OB3b, Methylomicrobium alcaliphilum 20Z, and Methylomonas sp. DH-1 as the biocatalysts. The biocatalytic process of converting propane to 2-propanol was optimized by the use of several inhibitors and additives, such as EDTA, sodium phosphate, and sodium formate to prevent oxidation of 2-propanol to acetone and to enhance conversion of propane to propanol. The maximum titer of 2-propanol was 0.424 g/L, 0.311 g/L, and 0.610 g/L for Methylomonas sp. DH-1, M. alcaliphilum 20Z, and M. trichosporium OB3b whole cells, respectively. These results showed that type I and type II methanotrophs could be used as the potent biocatalyst for conversion of propane to propanol.
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21
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Sowani H, Kulkarni M, Zinjarde S. Harnessing the catabolic versatility of Gordonia species for detoxifying pollutants. Biotechnol Adv 2019; 37:382-402. [DOI: 10.1016/j.biotechadv.2019.02.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 01/12/2019] [Accepted: 02/11/2019] [Indexed: 11/26/2022]
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22
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Ji N, Wang X, Yin C, Peng W, Liang R. CrgA Protein Represses AlkB2 Monooxygenase and Regulates the Degradation of Medium-to-Long-Chain n-Alkanes in Pseudomonas aeruginosa SJTD-1. Front Microbiol 2019; 10:400. [PMID: 30915046 PMCID: PMC6422896 DOI: 10.3389/fmicb.2019.00400] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/15/2019] [Indexed: 11/13/2022] Open
Abstract
AlkB monooxygenases in bacteria are responsible for the hydroxylation of medium- and long-chain n-alkanes. In this study, one CrgA protein of Pseudomonas aeruginosa SJTD-1, a member of LysR family, was proved to regulate AlkB2 monooxygenase and the degradation of medium-to-long-chain n-alkanes (C14-C20) by directly binding to the upstream of alkB2 gene. Two specific sites for CrgA binding were found in the promoter region of alkB2 gene, and the imperfect mirror repeat (IIR) structure was proved critical for CrgA recognition and binding. Hexadecyl CoA and octadecyl CoA could effectively release the CrgA binding and start the transcription of alkB2 gene, implying a positive regulation of metabolic intermediate. In the presence of medium-to-long-chain n-alkanes (C14-C20), deletion of crgA gene could enhance the transcription and expression of AlkB2 monooxygenase significantly; and in n-octadecane culture, strain S1ΔalkB1&crgA grew more vigorously than strain S1 ΔalkB1 &crgA . Almost no regulation of CrgA protein was observed to alkB1 gene in vitro and in vivo. Therefore, CrgA acted as a negative regulator for the medium-to-long-chain n-alkane utilization in P. aeruginosa SJTD-1. The work will promote the regulation mechanism study of n-alkane degradation in bacteria and help the bioremediation method development for petroleum pollution.
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Affiliation(s)
- Nannan Ji
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiuli Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Chong Yin
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Wanli Peng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Rubing Liang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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23
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Osborne CD, Haritos VS. Horizontal gene transfer of three co-inherited methane monooxygenase systems gave rise to methanotrophy in the Proteobacteria. Mol Phylogenet Evol 2018; 129:171-181. [PMID: 30149053 DOI: 10.1016/j.ympev.2018.08.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/01/2018] [Accepted: 08/19/2018] [Indexed: 12/22/2022]
Abstract
The critical role that bacterial methanotrophs have in regulating the environmental concentrations of the potent greenhouse gas, methane, under aerobic conditions is dependent on monooxygenase enzymes which oxidise the substrate as both a carbon and energy source. Despite the importance of these organisms, the evolutionary origins of aerobic methane oxidation capability and its relationship to proteobacterial evolution is not well understood. Here we investigated the phylogenetic relationship of proteobacterial methanotrophs with related, non-methanotrophic bacteria using 16S rRNA and the evolution of two forms of methane monooxygenase: membrane bound (pMMO and pXMO) and cytoplasmic (sMMO). Through analysis we have concluded that extant proteobacterial methanotrophs evolved from up to five ancestral species, and that all three methane monooxygenase systems, pMMO, pXMO and sMMO, were likely present in the ancestral species (although pXMO and sMMO are not present in most of the present day methanotrophs). Here we propose that the three monooxygenase systems entered the ancestral species by horizontal gene transfer, with these likely to have pre-existing physiological and metabolic attributes that supported conversion to methanotrophy. Further, we suggest that prior to these enzyme systems developing methane oxidation capabilities, the membrane-bound and cytoplasmic monooxygenases were already both functionally and phylogenetically associated. These results not only suggest that sMMO and pXMO have a far greater role in methanotrophic evolution than previously understood but also implies that the co-inheritance of membrane bound and cytoplasmic monooxygenases have roles additional to that of supporting methanotrophy.
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Affiliation(s)
- Craig D Osborne
- Department of Chemical Engineering, Monash University, Wellington Road, Clayton 3800, Australia
| | - Victoria S Haritos
- Department of Chemical Engineering, Monash University, Wellington Road, Clayton 3800, Australia.
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24
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McCarl V, Somerville MV, Ly MA, Henry R, Liew EF, Wilson NL, Holmes AJ, Coleman NV. Heterologous Expression of Mycobacterium Alkene Monooxygenases in Gram-Positive and Gram-Negative Bacterial Hosts. Appl Environ Microbiol 2018; 84:e00397-18. [PMID: 29802186 PMCID: PMC6052275 DOI: 10.1128/aem.00397-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/15/2018] [Indexed: 01/01/2023] Open
Abstract
Alkene monooxygenases (MOs) are soluble di-iron-containing enzymes found in bacteria that grow on alkenes. Here, we report improved heterologous expression systems for the propene MO (PmoABCD) and ethene MO (EtnABCD) from Mycobacterium chubuense strain NBB4. Strong functional expression of PmoABCD and EtnABCD was achieved in Mycobacterium smegmatis mc2155, yielding epoxidation activities (62 and 27 nmol/min/mg protein, respectively) higher than any reported to date for heterologous expression of a di-iron MO system. Both PmoABCD and EtnABCD were specialized for the oxidation of gaseous alkenes (C2 to C4), and their activity was much lower on liquid alkenes (C5 to C8). Despite intensive efforts to express the complete EtnABCD enzyme in Escherichia coli, this was not achieved, although recombinant EtnB and EtnD proteins could be purified individually in soluble form. The biochemical function of EtnD as an oxidoreductase was confirmed (1.36 μmol cytochrome c reduced/min/mg protein). Cloning the EtnABCD gene cluster into Pseudomonas putida KT2440 yielded detectable epoxidation of ethene (0.5 nmol/min/mg protein), and this could be stimulated (up to 1.1 nmol/min/mg protein) by the coexpression of cpn60 chaperonins from either Mycobacterium spp. or E. coli Successful expression of the ethene MO in a Gram-negative host was validated by both whole-cell activity assays and peptide mass spectrometry of induced proteins seen on SDS-PAGE gels.IMPORTANCE Alkene MOs are of interest for their potential roles in industrial biocatalysis, most notably for the stereoselective synthesis of epoxides. Wild-type bacteria that grow on alkenes have high activities for alkene oxidation but are problematic for biocatalysis, since they tend to consume the epoxide products. Using recombinant biocatalysts is the obvious alternative, but a major bottleneck is the low activities of recombinant alkene MOs. Here, we provide new high-activity recombinant biocatalysts for alkene oxidation, and we provide insights into how to further improve these systems.
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Affiliation(s)
- Victoria McCarl
- School of Life and Environmental Sciences, University of Sydney, NSW, Australia
| | - Mark V Somerville
- School of Life and Environmental Sciences, University of Sydney, NSW, Australia
| | - Mai-Anh Ly
- School of Life and Environmental Sciences, University of Sydney, NSW, Australia
| | - Rebecca Henry
- School of Life and Environmental Sciences, University of Sydney, NSW, Australia
| | - Elissa F Liew
- School of Life and Environmental Sciences, University of Sydney, NSW, Australia
| | - Neil L Wilson
- School of Life and Environmental Sciences, University of Sydney, NSW, Australia
| | - Andrew J Holmes
- School of Life and Environmental Sciences, University of Sydney, NSW, Australia
| | - Nicholas V Coleman
- School of Life and Environmental Sciences, University of Sydney, NSW, Australia
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25
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Heine T, Zimmerling J, Ballmann A, Kleeberg SB, Rückert C, Busche T, Winkler A, Kalinowski J, Poetsch A, Scholtissek A, Oelschlägel M, Schmidt G, Tischler D. On the Enigma of Glutathione-Dependent Styrene Degradation in Gordonia rubripertincta CWB2. Appl Environ Microbiol 2018; 84:e00154-18. [PMID: 29475871 PMCID: PMC5930330 DOI: 10.1128/aem.00154-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 02/19/2018] [Indexed: 02/05/2023] Open
Abstract
Among bacteria, only a single styrene-specific degradation pathway has been reported so far. It comprises the activity of styrene monooxygenase, styrene oxide isomerase, and phenylacetaldehyde dehydrogenase, yielding phenylacetic acid as the central metabolite. The alternative route comprises ring-hydroxylating enzymes and yields vinyl catechol as central metabolite, which undergoes meta-cleavage. This was reported to be unspecific and also allows the degradation of benzene derivatives. However, some bacteria had been described to degrade styrene but do not employ one of those routes or only parts of them. Here, we describe a novel "hybrid" degradation pathway for styrene located on a plasmid of foreign origin. As putatively also unspecific, it allows metabolizing chemically analogous compounds (e.g., halogenated and/or alkylated styrene derivatives). Gordonia rubripertincta CWB2 was isolated with styrene as the sole source of carbon and energy. It employs an assembled route of the styrene side-chain degradation and isoprene degradation pathways that also funnels into phenylacetic acid as the central metabolite. Metabolites, enzyme activity, genome, transcriptome, and proteome data reinforce this observation and allow us to understand this biotechnologically relevant pathway, which can be used for the production of ibuprofen.IMPORTANCE The degradation of xenobiotics by bacteria is not only important for bioremediation but also because the involved enzymes are potential catalysts in biotechnological applications. This study reveals a novel degradation pathway for the hazardous organic compound styrene in Gordonia rubripertincta CWB2. This study provides an impressive illustration of horizontal gene transfer, which enables novel metabolic capabilities. This study presents glutathione-dependent styrene metabolization in an (actino-)bacterium. Further, the genomic background of the ability of strain CWB2 to produce ibuprofen is demonstrated.
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Affiliation(s)
- Thomas Heine
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Anne Ballmann
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Christian Rückert
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Tobias Busche
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Anika Winkler
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Jörn Kalinowski
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Ansgar Poetsch
- Plant Biochemistry, Ruhr University Bochum, Bochum, Germany
- School of Biomedical and Healthcare Sciences, Plymouth University, Plymouth, United Kingdom
| | - Anika Scholtissek
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Gert Schmidt
- Institut für Keramik, Glas- und Baustofftechnik, TU Bergakademie Freiberg, Freiberg, Germany
| | - Dirk Tischler
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
- Microbial Biotechnology, Ruhr University Bochum, Bochum, Germany
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26
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Tupa PR, Masuda H. Genomic Analysis of Propane Metabolism in Methyl Tert-Butyl Ether-Degrading Mycobacterium Sp. Strain ENV421. J Genomics 2018; 6:24-29. [PMID: 29576806 PMCID: PMC5865082 DOI: 10.7150/jgen.24929] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 02/21/2018] [Indexed: 11/05/2022] Open
Abstract
Methyl tert-butyl ether (MTBE) is a ground water contaminant with plausible carcinogenic properties. Mycobacterium sp. strain ENV421 cometabolically degrades MTBE and other ethers during the growth on propane as a carbon source. In this study, the 6.2 Mb genome of strain ENV421 was deciphered. The genome sequence revealed the presence of numerous putative propane catabolic genes including genes encoding hydrocarbon oxygenases and short chain alcohol dehydrogenases. These data provide the basis for the elucidation of propane metabolic pathways in strain ENV421 and its application for the remediation of ground water contaminated with toxic ethers.
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Affiliation(s)
- Peter Robert Tupa
- School of Sciences, Indiana University Kokomo, Kokomo, Indiana, 46902, United States of America
| | - Hisako Masuda
- School of Sciences, Indiana University Kokomo, Kokomo, Indiana, 46902, United States of America
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Draft Genome Sequence of a Propanotroph, Rhodococcus sp. Strain ENV425, Capable of Degrading Methyl tert-Butyl Ether and N-Nitrosodimethylamine. GENOME ANNOUNCEMENTS 2018; 6:6/8/e00051-18. [PMID: 29472328 PMCID: PMC5824016 DOI: 10.1128/genomea.00051-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In this study, the draft genome of Rhodococcus sp. strain ENV425 was determined. The propane-grown strain ENV425 cometabolically degrades environmental contaminants such as methyl tert-butyl ether and N-nitrosodimethylamine. The sequence revealed the presence of multiple hydrocarbon metabolic genes that could play pivotal roles in the biodegradation of pollutants.
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Microbial cycling of isoprene, the most abundantly produced biological volatile organic compound on Earth. ISME JOURNAL 2018; 12:931-941. [PMID: 29463892 PMCID: PMC5864225 DOI: 10.1038/s41396-018-0072-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/26/2017] [Accepted: 12/12/2017] [Indexed: 01/28/2023]
Abstract
Isoprene (2-methyl-1,3-butadiene), the most abundantly produced biogenic volatile organic compound (BVOC) on Earth, is highly reactive and can have diverse and often detrimental atmospheric effects, which impact on climate and health. Most isoprene is produced by terrestrial plants, but (micro)algal production is important in aquatic environments, and the relative bacterial contribution remains unknown. Soils are a sink for isoprene, and bacteria that can use isoprene as a carbon and energy source have been cultivated and also identified using cultivation-independent methods from soils, leaves and coastal/marine environments. Bacteria belonging to the Actinobacteria are most frequently isolated and identified, and Proteobacteria have also been shown to degrade isoprene. In the freshwater-sediment isolate, Rhodococcus strain AD45, initial oxidation of isoprene to 1,2-epoxy-isoprene is catalyzed by a multicomponent isoprene monooxygenase encoded by the genes isoABCDEF. The resultant epoxide is converted to a glutathione conjugate by a glutathione S-transferase encoded by isoI, and further degraded by enzymes encoded by isoGHJ. Genome sequence analysis of actinobacterial isolates belonging to the genera Rhodococcus, Mycobacterium and Gordonia has revealed that isoABCDEF and isoGHIJ are linked in an operon, either on a plasmid or the chromosome. In Rhodococcus strain AD45 both isoprene and epoxy-isoprene induce a high level of transcription of 22 contiguous genes, including isoABCDEF and isoGHIJ. Sequence analysis of the isoA gene, encoding the large subunit of the oxygenase component of isoprene monooxygenase, from isolates has facilitated the development of PCR primers that are proving valuable in investigating the ecology of uncultivated isoprene-degrading bacteria.
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Draft Genome Sequences of Three Terrestrial Isoprene-Degrading Rhodococcus Strains. GENOME ANNOUNCEMENTS 2017; 5:5/45/e01256-17. [PMID: 29122877 PMCID: PMC5679810 DOI: 10.1128/genomea.01256-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Isoprene is produced in abundance by plants and constitutes a carbon source for microbes. The genomes of three isoprene degraders isolated from tree leaves or soil from the campus of the University of East Anglia were sequenced. These high-GC-content isolates are actinobacteria belonging to the genus Rhodococcus.
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30
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Jiang Y, Chen T, Dong W, Zhang M, Zhang W, Wu H, Ma J, Jiang M, Xin F. The Draft Genome Sequence of Clostridium beijerinckii NJP7, a Unique Bacterium Capable of Producing Isopropanol-Butanol from Hemicellulose Through Consolidated Bioprocessing. Curr Microbiol 2017; 75:305-308. [PMID: 29063966 DOI: 10.1007/s00284-017-1380-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 10/20/2017] [Indexed: 12/13/2022]
Abstract
A wild type solventogenic Clostridium beijerinckii NJP7 capable of converting polysaccharides, such as hemicellulose, into butanol and isopropanol via a unique acetone-isopropanol-butanol (AIB) pathway was isolated and characterized. This represents the first wild type isopropanol-butanol generating bacterium which could achieve butanol production directly from lignocellulose through consolidated bioprocessing (CBP). Strain NJP7 was isolated from decomposite soil from Laoshan Nature Park, China, and its genome shows 98.6% identical to 89.5% of the Clostridium diolis submitted genome sequence. The assembled draft genome contains 5.76 Mb and 5101 predicted encoding proteins with a GC content of 29.73%. Among these annotated proteins, hemicellulase and the secondary alcohol dehydrogenase play key roles in achievement of AIB production from hemicellulose through CBP.
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Affiliation(s)
- Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Tianpeng Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Min Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China
| | - Hao Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China
| | - Jiangfeng Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China.
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China.
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31
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Johnston A, Crombie AT, El Khawand M, Sims L, Whited GM, McGenity TJ, Colin Murrell J. Identification and characterisation of isoprene-degrading bacteria in an estuarine environment. Environ Microbiol 2017; 19:3526-3537. [PMID: 28654185 PMCID: PMC6849523 DOI: 10.1111/1462-2920.13842] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/31/2017] [Accepted: 06/19/2017] [Indexed: 11/30/2022]
Abstract
Approximately one‐third of volatile organic compounds (VOCs) emitted to the atmosphere consists of isoprene, originating from the terrestrial and marine biosphere, with a profound effect on atmospheric chemistry. However, isoprene provides an abundant and largely unexplored source of carbon and energy for microbes. The potential for isoprene degradation in marine and estuarine samples from the Colne Estuary, UK, was investigated using DNA‐Stable Isotope Probing (DNA‐SIP). Analysis at two timepoints showed the development of communities dominated by Actinobacteria including members of the genera Mycobacterium, Rhodococcus, Microbacterium and Gordonia. Representative isolates, capable of growth on isoprene as sole carbon and energy source, were obtained from marine and estuarine locations, and isoprene‐degrading strains of Gordonia and Mycobacterium were characterised physiologically and their genomes were sequenced. Genes predicted to be required for isoprene metabolism, including four‐component isoprene monooxygenases (IsoMO), were identified and compared with previously characterised examples. Transcriptional and activity assays of strains growing on isoprene or alternative carbon sources showed that growth on isoprene is an inducible trait requiring a specific IsoMO. This study is the first to identify active isoprene degraders in estuarine and marine environments using DNA‐SIP and to characterise marine isoprene‐degrading bacteria at the physiological and molecular level.
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Affiliation(s)
- Antonia Johnston
- School of Environmental Science, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Andrew T Crombie
- School of Environmental Science, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Myriam El Khawand
- School of Environmental Science, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Leanne Sims
- School of Environmental Science, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Gregg M Whited
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Terry J McGenity
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - J Colin Murrell
- School of Environmental Science, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.,Earth and Life Systems Alliance, Norwich Research Park, Norwich, UK
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32
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33
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Brown ME, Mukhopadhyay A, Keasling JD. Engineering Bacteria to Catabolize the Carbonaceous Component of Sarin: Teaching E. coli to Eat Isopropanol. ACS Synth Biol 2016; 5:1485-1496. [PMID: 27403844 DOI: 10.1021/acssynbio.6b00115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report an engineered strain of Escherichia coli that catabolizes the carbonaceous component of the extremely toxic chemical warfare agent sarin. Enzymatic decomposition of sarin generates isopropanol waste that, with this engineered strain, is then transformed into acetyl-CoA by enzymatic conversion with a key reaction performed by the acetone carboxylase complex (ACX). We engineered the heterologous expression of the ACX complex from Xanthobacter autotrophicus PY2 to match the naturally occurring subunit stoichiometry and purified the recombinant complex from E. coli for biochemical analysis. Incorporating this ACX complex and enzymes from diverse organisms, we introduced an isopropanol degradation pathway in E. coli, optimized induction conditions, and decoupled enzyme expression to probe pathway bottlenecks. Our engineered E. coli consumed 65% of isopropanol compared to no-cell controls and was able to grow on isopropanol as a sole carbon source. In the process, reconstitution of this large ACX complex (370 kDa) in a system naïve to its structural and mechanistic requirements allowed us to study this otherwise cryptic enzyme in more detail than would have been possible in the less genetically tractable native Xanthobacter system.
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Affiliation(s)
- Margaret E. Brown
- Biological
Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint BioEnergy Institute, Emeryville, California 94608, United States
| | - Aindrila Mukhopadhyay
- Biological
Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint BioEnergy Institute, Emeryville, California 94608, United States
| | - Jay D. Keasling
- Biological
Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Novo
Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kogle Alle, DK2970-Hørsholm, Denmark
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34
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Gkorezis P, Daghio M, Franzetti A, Van Hamme JD, Sillen W, Vangronsveld J. The Interaction between Plants and Bacteria in the Remediation of Petroleum Hydrocarbons: An Environmental Perspective. Front Microbiol 2016; 7:1836. [PMID: 27917161 PMCID: PMC5116465 DOI: 10.3389/fmicb.2016.01836] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 11/01/2016] [Indexed: 11/24/2022] Open
Abstract
Widespread pollution of terrestrial ecosystems with petroleum hydrocarbons (PHCs) has generated a need for remediation and, given that many PHCs are biodegradable, bio- and phyto-remediation are often viable approaches for active and passive remediation. This review focuses on phytoremediation with particular interest on the interactions between and use of plant-associated bacteria to restore PHC polluted sites. Plant-associated bacteria include endophytic, phyllospheric, and rhizospheric bacteria, and cooperation between these bacteria and their host plants allows for greater plant survivability and treatment outcomes in contaminated sites. Bacterially driven PHC bioremediation is attributed to the presence of diverse suites of metabolic genes for aliphatic and aromatic hydrocarbons, along with a broader suite of physiological properties including biosurfactant production, biofilm formation, chemotaxis to hydrocarbons, and flexibility in cell-surface hydrophobicity. In soils impacted by PHC contamination, microbial bioremediation generally relies on the addition of high-energy electron acceptors (e.g., oxygen) and fertilization to supply limiting nutrients (e.g., nitrogen, phosphorous, potassium) in the face of excess PHC carbon. As an alternative, the addition of plants can greatly improve bioremediation rates and outcomes as plants provide microbial habitats, improve soil porosity (thereby increasing mass transfer of substrates and electron acceptors), and exchange limiting nutrients with their microbial counterparts. In return, plant-associated microorganisms improve plant growth by reducing soil toxicity through contaminant removal, producing plant growth promoting metabolites, liberating sequestered plant nutrients from soil, fixing nitrogen, and more generally establishing the foundations of soil nutrient cycling. In a practical and applied sense, the collective action of plants and their associated microorganisms is advantageous for remediation of PHC contaminated soil in terms of overall cost and success rates for in situ implementation in a diversity of environments. Mechanistically, there remain biological unknowns that present challenges for applying bio- and phyto-remediation technologies without having a deep prior understanding of individual target sites. In this review, evidence from traditional and modern omics technologies is discussed to provide a framework for plant-microbe interactions during PHC remediation. The potential for integrating multiple molecular and computational techniques to evaluate linkages between microbial communities, plant communities and ecosystem processes is explored with an eye on improving phytoremediation of PHC contaminated sites.
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Affiliation(s)
- Panagiotis Gkorezis
- Environmental Biology, Centre for Environmental Sciences, Hasselt UniversityDiepenbeek, Belgium
| | - Matteo Daghio
- Department of Environmental Sciences, University of Milano-BicoccaMilano, Italy
- Department of Biological Sciences, Thompson Rivers University, KamloopsBC, Canada
| | - Andrea Franzetti
- Department of Environmental Sciences, University of Milano-BicoccaMilano, Italy
| | | | - Wouter Sillen
- Environmental Biology, Centre for Environmental Sciences, Hasselt UniversityDiepenbeek, Belgium
| | - Jaco Vangronsveld
- Environmental Biology, Centre for Environmental Sciences, Hasselt UniversityDiepenbeek, Belgium
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Kandasamy V, Liu J, Dantoft SH, Solem C, Jensen PR. Synthesis of (3R)-acetoin and 2,3-butanediol isomers by metabolically engineered Lactococcus lactis. Sci Rep 2016; 6:36769. [PMID: 27857195 PMCID: PMC5114678 DOI: 10.1038/srep36769] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/20/2016] [Indexed: 12/18/2022] Open
Abstract
The potential that lies in harnessing the chemical synthesis capabilities inherent in living organisms is immense. Here we demonstrate how the biosynthetic machinery of Lactococcus lactis, can be diverted to make (3R)-acetoin and the derived 2,3-butanediol isomers meso-(2,3)-butanediol (m-BDO) and (2R,3R)-butanediol (R-BDO). Efficient production of (3R)-acetoin was accomplished using a strain where the competing lactate, acetate and ethanol forming pathways had been blocked. By introducing different alcohol dehydrogenases into this strain, either EcBDH from Enterobacter cloacae or SadB from Achromobacter xylosooxidans, it was possible to achieve high-yield production of m-BDO or R-BDO respectively. To achieve biosustainable production of these chemicals from dairy waste, we transformed the above strains with the lactose plasmid pLP712. This enabled efficient production of (3R)-acetoin, m-BDO and R-BDO from processed whey waste, with titers of 27, 51, and 32 g/L respectively. The corresponding yields obtained were 0.42, 0.47 and 0.40 g/g lactose, which is 82%, 89%, and 76% of maximum theoretical yield respectively. These results clearly demonstrate that L. lactis is an excellent choice as a cell factory for transforming lactose containing dairy waste into value added chemicals.
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Affiliation(s)
| | - Jianming Liu
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Shruti Harnal Dantoft
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Christian Solem
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Peter Ruhdal Jensen
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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Complete Genome Sequence of Bacillus pumilus PDSLzg-1, a Hydrocarbon-Degrading Bacterium Isolated from Oil-Contaminated Soil in China. GENOME ANNOUNCEMENTS 2016; 4:4/5/e01079-16. [PMID: 27795249 PMCID: PMC5054320 DOI: 10.1128/genomea.01079-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Bacillus pumilus strain PDSLzg-1, an efficient hydrocarbon-degrading bacterium, was isolated from oil-contaminated soil. Here, we present the complete sequence of its circular chromosome and circular plasmid. The genomic information is essential for the study of degradation of oil by B. pumilus PDSLzg-1.
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37
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Wang X, Zhao X, Li H, Jia J, Liu Y, Ejenavi O, Ding A, Sun Y, Zhang D. Separating and characterizing functional alkane degraders from crude-oil-contaminated sites via magnetic nanoparticle-mediated isolation. Res Microbiol 2016; 167:731-744. [PMID: 27475037 DOI: 10.1016/j.resmic.2016.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 07/06/2016] [Accepted: 07/08/2016] [Indexed: 11/18/2022]
Abstract
Uncultivable microorganisms account for over 99% of all species on the planet, but their functions are yet not well characterized. Though many cultivable degraders for n-alkanes have been intensively investigated, the roles of functional n-alkane degraders remain hidden in the natural environment. This study introduces the novel magnetic nanoparticle-mediated isolation (MMI) technology in Nigerian soils and successfully separates functional microbes belonging to the families Oxalobacteraceae and Moraxellaceae, which are dominant and responsible for alkane metabolism in situ. The alkR-type n-alkane monooxygenase genes, instead of alkA- or alkP-type, were the key functional genes involved in the n-alkane degradation process. Further physiological investigation via a BIOLOG PM plate revealed some carbon (Tween 20, Tween 40 and Tween 80) and nitrogen (tyramine, l-glutamine and d-aspartic acid) sources promoting microbial respiration and n-alkane degradation. With further addition of promoter carbon or nitrogen sources, the separated functional alkane degraders significantly improved n-alkane biodegradation rates. This suggests that MMI is a promising technology for separating functional microbes from complex microbiota, with deeper insight into their ecological functions and influencing factors. The technique also broadens the application of the BIOLOG PM plate for physiological research on functional yet uncultivable microorganisms.
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Affiliation(s)
- Xinzi Wang
- Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ, UK
| | - Xiaohui Zhao
- Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ, UK; College of Water Sciences, Beijing Normal University, Beijing 100875, PR China
| | - Hanbing Li
- Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ, UK
| | - Jianli Jia
- School of Chemical and Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, PR China
| | - Yueqiao Liu
- Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ, UK; College of Water Sciences, Beijing Normal University, Beijing 100875, PR China
| | - Odafe Ejenavi
- Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ, UK
| | - Aizhong Ding
- College of Water Sciences, Beijing Normal University, Beijing 100875, PR China
| | - Yujiao Sun
- College of Water Sciences, Beijing Normal University, Beijing 100875, PR China
| | - Dayi Zhang
- Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ, UK.
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38
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Liang JL, Nie Y, Wang M, Xiong G, Wang YP, Maser E, Wu XL. Regulation of alkane degradation pathway by a TetR family repressor via an autoregulation positive feedback mechanism in a Gram-positiveDietziabacterium. Mol Microbiol 2015; 99:338-59. [DOI: 10.1111/mmi.13232] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2015] [Indexed: 01/26/2023]
Affiliation(s)
- Jie-Liang Liang
- Department of Energy and Resources Engineering; College of Engineering; Peking University; Beijing 100871 China
| | - Yong Nie
- Department of Energy and Resources Engineering; College of Engineering; Peking University; Beijing 100871 China
| | - Miaoxiao Wang
- Department of Energy and Resources Engineering; College of Engineering; Peking University; Beijing 100871 China
| | - Guangming Xiong
- Institute of Toxicology and Pharmacology for Natural Scientists; University Medical School; Schleswig-Holstein, Campus Kiel Kiel 24105 Germany
| | - Yi-Ping Wang
- State Key Laboratory of Protein and Plant Gene Research; College of Life Sciences; Peking University; Beijing 100871 China
| | - Edmund Maser
- Institute of Toxicology and Pharmacology for Natural Scientists; University Medical School; Schleswig-Holstein, Campus Kiel Kiel 24105 Germany
| | - Xiao-Lei Wu
- Department of Energy and Resources Engineering; College of Engineering; Peking University; Beijing 100871 China
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Crombie AT, Khawand ME, Rhodius VA, Fengler KA, Miller MC, Whited GM, McGenity TJ, Murrell JC. Regulation of plasmid-encoded isoprene metabolism in Rhodococcus, a representative of an important link in the global isoprene cycle. Environ Microbiol 2015; 17:3314-29. [PMID: 25727256 PMCID: PMC4676930 DOI: 10.1111/1462-2920.12793] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 01/26/2015] [Indexed: 01/25/2023]
Abstract
Emissions of biogenic volatile organic compounds (VOCs) form an important part of the global carbon cycle, comprising a significant proportion of net ecosystem productivity. They impact atmospheric chemistry and contribute directly and indirectly to greenhouse gases. Isoprene, emitted largely from plants, comprises one third of total VOCs, yet in contrast to methane, which is released in similar quantities, we know little of its biodegradation. Here, we report the genome of an isoprene degrading isolate, Rhodococcus sp. AD45, and, using mutagenesis shows that a plasmid-encoded soluble di-iron centre isoprene monooxygenase (IsoMO) is essential for isoprene metabolism. Using RNA sequencing (RNAseq) to analyse cells exposed to isoprene or epoxyisoprene in a substrate-switch time-course experiment, we show that transcripts from 22 contiguous genes, including those encoding IsoMO, were highly upregulated, becoming among the most abundant in the cell and comprising over 25% of the entire transcriptome. Analysis of gene transcription in the wild type and an IsoMO-disrupted mutant strain showed that epoxyisoprene, or a subsequent product of isoprene metabolism, rather than isoprene itself, was the inducing molecule. We provide a foundation of molecular data for future research on the environmental biological consumption of this important, climate-active compound.
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Affiliation(s)
| | | | - Virgil A Rhodius
- DuPont Industrial Biosciences925 Page Mill Road, Palo Alto, CA, 94304, USA
| | | | - Michael C Miller
- DuPont Industrial Biosciences925 Page Mill Road, Palo Alto, CA, 94304, USA
| | - Gregg M Whited
- DuPont Industrial Biosciences925 Page Mill Road, Palo Alto, CA, 94304, USA
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40
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Furuya T, Nakao T, Kino K. Catalytic function of the mycobacterial binuclear iron monooxygenase in acetone metabolism. FEMS Microbiol Lett 2015; 362:fnv136. [PMID: 26293913 DOI: 10.1093/femsle/fnv136] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2015] [Indexed: 11/13/2022] Open
Abstract
Mycobacteria such as Mycobacterium smegmatis strain mc(2)155 and Mycobacterium goodii strain 12523 are able to grow on acetone and use it as a source of carbon and energy. We previously demonstrated by gene deletion analysis that the mimABCD gene cluster, which encodes a binuclear iron monooxygenase, plays an essential role in acetone metabolism in these mycobacteria. In the present study, we determined the catalytic function of MimABCD in acetone metabolism. Whole-cell assays were performed using Escherichia coli cells expressing the MimABCD complex. When the recombinant E. coli cells were incubated with acetone, a product was detected by gas chromatography (GC) analysis. Based on the retention time and the gas chromatography-mass spectrometry (GC-MS) spectrum, the reaction product was identified as acetol (hydroxyacetone). The recombinant E. coli cells produced 1.02 mM of acetol from acetone within 24 h. Furthermore, we demonstrated that MimABCD also was able to convert methylethylketone (2-butanone) to 1-hydroxy-2-butanone. Although it has long been known that microorganisms such as mycobacteria metabolize acetone via acetol, this study provides the first biochemical evidence for the existence of a microbial enzyme that catalyses the conversion of acetone to acetol.
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Affiliation(s)
- Toshiki Furuya
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Tomomi Nakao
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Kuniki Kino
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
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41
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Cappelletti M, Presentato A, Milazzo G, Turner RJ, Fedi S, Frascari D, Zannoni D. Growth of Rhodococcus sp. strain BCP1 on gaseous n-alkanes: new metabolic insights and transcriptional analysis of two soluble di-iron monooxygenase genes. Front Microbiol 2015; 6:393. [PMID: 26029173 PMCID: PMC4428276 DOI: 10.3389/fmicb.2015.00393] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/16/2015] [Indexed: 11/16/2022] Open
Abstract
Rhodococcus sp. strain BCP1 was initially isolated for its ability to grow on gaseous n-alkanes, which act as inducers for the co-metabolic degradation of low-chlorinated compounds. Here, both molecular and metabolic features of BCP1 cells grown on gaseous and short-chain n-alkanes (up to n-heptane) were examined in detail. We show that propane metabolism generated terminal and sub-terminal oxidation products such as 1- and 2-propanol, whereas 1-butanol was the only terminal oxidation product detected from n-butane metabolism. Two gene clusters, prmABCD and smoABCD—coding for Soluble Di-Iron Monooxgenases (SDIMOs) involved in gaseous n-alkanes oxidation—were detected in the BCP1 genome. By means of Reverse Transcriptase-quantitative PCR (RT-qPCR) analysis, a set of substrates inducing the expression of the sdimo genes in BCP1 were assessed as well as their transcriptional repression in the presence of sugars, organic acids, or during the cell growth on rich medium (Luria–Bertani broth). The transcriptional start sites of both the sdimo gene clusters were identified by means of primer extension experiments. Finally, proteomic studies revealed changes in the protein pattern induced by growth on gaseous- (n-butane) and/or liquid (n-hexane) short-chain n-alkanes as compared to growth on succinate. Among the differently expressed protein spots, two chaperonins and an isocytrate lyase were identified along with oxidoreductases involved in oxidation reactions downstream of the initial monooxygenase reaction step.
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Affiliation(s)
- Martina Cappelletti
- Department of Pharmacy and Biotechnology, University of Bologna Bologna, Italy
| | | | - Giorgio Milazzo
- Department of Pharmacy and Biotechnology, University of Bologna Bologna, Italy
| | - Raymond J Turner
- Department of Biological Sciences, University of Calgary Calgary, Alberta, Canada
| | - Stefano Fedi
- Department of Pharmacy and Biotechnology, University of Bologna Bologna, Italy
| | - Dario Frascari
- Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna Bologna, Italy
| | - Davide Zannoni
- Department of Pharmacy and Biotechnology, University of Bologna Bologna, Italy
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42
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The anaerobic degradation of gaseous, nonmethane alkanes - From in situ processes to microorganisms. Comput Struct Biotechnol J 2015; 13:222-8. [PMID: 25904994 PMCID: PMC4402382 DOI: 10.1016/j.csbj.2015.03.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 03/10/2015] [Accepted: 03/16/2015] [Indexed: 11/23/2022] Open
Abstract
The short chain, gaseous alkanes ethane, propane, n- and iso-butane are released in significant amounts into the atmosphere, where they contribute to tropospheric chemistry and ozone formation. Biodegradation of gaseous alkanes by aerobic microorganisms, mostly bacteria and fungi isolated from terrestrial environments, has been known for several decades. The first indications for short chain alkane anaerobic degradation were provided by geochemical studies of deep-sea environments around hydrocarbon seeps, and included the uncoupling of the sulfate-reduction and anaerobic oxidation of methane rates, the consumption of gaseous alkanes in anoxic sediments, or the enrichment in (13)C of gases in interstitial water vs. the source gas. Microorganisms able to degrade gaseous alkanes were recently obtained from deep-sea and terrestrial sediments around hydrocarbon seeps. Up to date, only sulfate-reducing pure or enriched cultures with ethane, propane and n-butane have been reported. The only pure culture presently available, strain BuS5, is affiliated to the Desulfosarcina-Desulfococcus cluster of the Deltaproteobacteria. Other phylotypes involved in gaseous alkane degradation have been identified based on stable-isotope labeling and whole-cell hybridization. Under anoxic conditions, propane and n-butane are activated similar to the higher alkanes, by homolytic cleavage of the C-H bond of a subterminal carbon atom, and addition of the ensuing radical to fumarate, yielding methylalkylsuccinates. An additional mechanism of activation at the terminal carbon atoms was demonstrated for propane, which could in principle be employed also for the activation of ethane.
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43
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Ghiaci P, Norbeck J, Larsson C. 2-Butanol and butanone production in Saccharomyces cerevisiae through combination of a B12 dependent dehydratase and a secondary alcohol dehydrogenase using a TEV-based expression system. PLoS One 2014; 9:e102774. [PMID: 25054226 PMCID: PMC4108354 DOI: 10.1371/journal.pone.0102774] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 06/24/2014] [Indexed: 01/30/2023] Open
Abstract
2-Butanol and its chemical precursor butanone (methyl ethyl ketone – MEK) are chemicals with potential uses as biofuels and biocommodity chemicals. In order to produce 2-butanol, we have demonstrated the utility of using a TEV-protease based expression system to achieve equimolar expression of the individual subunits of the two protein complexes involved in the B12-dependent dehydratase step (from the pdu-operon of Lactobacillus reuterii), which catalyze the conversion of meso-2,3-butanediol to butanone. We have furthermore identified a NADH dependent secondary alcohol dehydrogenase (Sadh from Gordonia sp.) able to catalyze the subsequent conversion of butanone to 2-butanol. A final concentration of 4±0.2 mg/L 2-butanol and 2±0.1 mg/L of butanone was found. A key factor for the production of 2-butanol was the availability of NADH, which was achieved by growing cells lacking the GPD1 and GPD2 isogenes under anaerobic conditions.
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Affiliation(s)
- Payam Ghiaci
- Department of Chemical and Biological Engineering, System and Synthetic Biology, Chalmers University of Technology, Gothenburg, Sweden
| | - Joakim Norbeck
- Department of Chemical and Biological Engineering, System and Synthetic Biology, Chalmers University of Technology, Gothenburg, Sweden
| | - Christer Larsson
- Department of Chemical and Biological Engineering, System and Synthetic Biology, Chalmers University of Technology, Gothenburg, Sweden
- * E-mail:
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44
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Trace-gas metabolic versatility of the facultative methanotroph Methylocella silvestris. Nature 2014; 510:148-51. [DOI: 10.1038/nature13192] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 02/26/2014] [Indexed: 11/08/2022]
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45
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Identification of biomarker genes to predict biodegradation of 1,4-dioxane. Appl Environ Microbiol 2014; 80:3209-18. [PMID: 24632253 DOI: 10.1128/aem.04162-13] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial multicomponent monooxygenase gene targets in Pseudonocardia dioxanivorans CB1190 were evaluated for their use as biomarkers to identify the potential for 1,4-dioxane biodegradation in pure cultures and environmental samples. Our studies using laboratory pure cultures and industrial activated sludge samples suggest that the presence of genes associated with dioxane monooxygenase, propane monooxygenase, alcohol dehydrogenase, and aldehyde dehydrogenase are promising indicators of 1,4-dioxane biotransformation; however, gene abundance was insufficient to predict actual biodegradation. A time course gene expression analysis of dioxane and propane monooxygenases in Pseudonocardia dioxanivorans CB1190 and mixed communities in wastewater samples revealed important associations with the rates of 1,4-dioxane removal. In addition, transcripts of alcohol dehydrogenase and aldehyde dehydrogenase genes were upregulated during biodegradation, although only the aldehyde dehydrogenase was significantly correlated with 1,4-dioxane concentrations. Expression of the propane monooxygenase demonstrated a time-dependent relationship with 1,4-dioxane biodegradation in P. dioxanivorans CB1190, with increased expression occurring after over 50% of the 1,4-dioxane had been removed. While the fraction of P. dioxanivorans CB1190-like bacteria among the total bacterial population significantly increased with decrease in 1,4-dioxane concentrations in wastewater treatment samples undergoing active biodegradation, the abundance and expression of monooxygenase-based biomarkers were better predictors of 1,4-dioxane degradation than taxonomic 16S rRNA genes. This study illustrates that specific bacterial monooxygenase and dehydrogenase gene targets together can serve as effective biomarkers for 1,4-dioxane biodegradation in the environment.
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46
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Kim JH, Kim SH, Yoon JH, Lee PC. Carotenoid production from n-alkanes with a broad range of chain lengths by the novel species Gordonia ajoucoccus A2T. Appl Microbiol Biotechnol 2014; 98:3759-68. [DOI: 10.1007/s00253-014-5516-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 12/29/2013] [Accepted: 12/30/2013] [Indexed: 11/30/2022]
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47
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Oxidation of the cyclic ethers 1,4-dioxane and tetrahydrofuran by a monooxygenase in two Pseudonocardia species. Appl Environ Microbiol 2013; 79:7702-8. [PMID: 24096414 DOI: 10.1128/aem.02418-13] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The bacterium Pseudonocardia dioxanivorans CB1190 grows on the cyclic ethers 1,4-dioxane (dioxane) and tetrahydrofuran (THF) as sole carbon and energy sources. Prior transcriptional studies indicated that an annotated THF monooxygenase (THF MO) gene cluster, thmADBC, located on a plasmid in CB1190 is upregulated during growth on dioxane. In this work, transcriptional analysis demonstrates that upregulation of thmADBC occurs during growth on the dioxane metabolite β-hydroxyethoxyacetic acid (HEAA) and on THF. Comparison of the transcriptomes of CB1190 grown on THF and succinate (an intermediate of THF degradation) permitted the identification of other genes involved in THF metabolism. Dioxane and THF oxidation activity of the THF MO was verified in Rhodococcus jostii RHA1 cells heterologously expressing the CB1190 thmADBC gene cluster. Interestingly, these thmADBC expression clones accumulated HEAA as a dead-end product of dioxane transformation, indicating that despite its genes being transcriptionally upregulated during growth on HEAA, the THF MO enzyme is not responsible for degradation of HEAA in CB1190. Similar activities were also observed in RHA1 cells heterologously expressing the thmADBC gene cluster from Pseudonocardia tetrahydrofuranoxydans K1.
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48
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Reconstitution of active mycobacterial binuclear iron monooxygenase complex in Escherichia coli. Appl Environ Microbiol 2013; 79:6033-9. [PMID: 23892738 DOI: 10.1128/aem.01856-13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial binuclear iron monooxygenases play numerous physiological roles in oxidative metabolism. Monooxygenases of this type found in actinomycetes also catalyze various useful reactions and have attracted much attention as oxidation biocatalysts. However, difficulties in expressing these multicomponent monooxygenases in heterologous hosts, particularly in Escherichia coli, have hampered the development of engineered oxidation biocatalysts. Here, we describe a strategy to functionally express the mycobacterial binuclear iron monooxygenase MimABCD in Escherichia coli. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of the mimABCD gene expression in E. coli revealed that the oxygenase components MimA and MimC were insoluble. Furthermore, although the reductase MimB was expressed at a low level in the soluble fraction of E. coli cells, a band corresponding to the coupling protein MimD was not evident. This situation rendered the transformed E. coli cells inactive. We found that the following factors are important for functional expression of MimABCD in E. coli: coexpression of the specific chaperonin MimG, which caused MimA and MimC to be soluble in E. coli cells, and the optimization of the mimD nucleotide sequence, which led to efficient expression of this gene product. These two remedies enabled this multicomponent monooxygenase to be actively expressed in E. coli. The strategy described here should be generally applicable to the E. coli expression of other actinomycetous binuclear iron monooxygenases and related enzymes and will accelerate the development of engineered oxidation biocatalysts for industrial processes.
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49
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Ji Y, Mao G, Wang Y, Bartlam M. Structural insights into diversity and n-alkane biodegradation mechanisms of alkane hydroxylases. Front Microbiol 2013; 4:58. [PMID: 23519435 PMCID: PMC3604635 DOI: 10.3389/fmicb.2013.00058] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 02/28/2013] [Indexed: 11/13/2022] Open
Abstract
Environmental microbes utilize four degradation pathways for the oxidation of n-alkanes. Although the enzymes degrading n-alkanes in different microbes may vary, enzymes functioning in the first step in the aerobic degradation of alkanes all belong to the alkane hydroxylases. Alkane hydroxylases are a class of enzymes that insert oxygen atoms derived from molecular oxygen into different sites of the alkane terminus (or termini) depending on the type of enzymes. In this review, we summarize the different types of alkane hydroxylases, their degrading steps, and compare typical enzymes from various classes with regard to their three-dimensional structures, in order to provide insights into how the enzymes mediate their different roles in the degradation of n-alkanes and what determines their different substrate ranges. Through the above analyzes, the degrading mechanisms of enzymes can be elucidated and molecular biological methods can be utilized to expand their catalytic roles in the petrochemical industry or in bioremediation of oil-contaminated environments.
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Affiliation(s)
- Yurui Ji
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai UniversityTianjin, China
- State Key Laboratory of Medicinal Chemical Biology, Nankai UniversityTianjin, China
| | - Guannan Mao
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai UniversityTianjin, China
| | - Yingying Wang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai UniversityTianjin, China
| | - Mark Bartlam
- State Key Laboratory of Medicinal Chemical Biology, Nankai UniversityTianjin, China
- College of Life Sciences, Nankai UniversityTianjin, China
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50
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Furuya T, Hayashi M, Semba H, Kino K. The mycobacterial binuclear iron monooxygenases require a specific chaperonin-like protein for functional expression in a heterologous host. FEBS J 2013; 280:817-26. [PMID: 23171424 DOI: 10.1111/febs.12070] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/06/2012] [Accepted: 11/14/2012] [Indexed: 11/30/2022]
Abstract
The mimABCD gene clusters in Mycobacterium smegmatis strain mc(2) 155 and Mycobacterium goodii strain 12523 encode binuclear iron monooxygenases that oxidize propane and phenol. In this study, we attempted to express each mimABCD gene cluster in a heterologous host. The actinomycetous strain Rhodococcus opacus B-4, which is phylogenetically close to Mycobacterium, was selected as the host. Each mimABCD gene cluster was cloned into the Rhodococcus-Escherichia coli shuttle vector, pTip-QC2, and then introduced into R. opacus cells. Although whole-cell assays were performed with phenol as a substrate, the transformed R. opacus cells did not oxidize this substrate. SDS/PAGE analysis revealed that the oxygenase large subunit MimA was expressed in the insoluble fraction of R. opacus cells. We found that a gene designated mimG, which lies downstream of mimABCD, exhibits similarity in the amino acid sequence of its product with the products of genes encoding the chaperonin GroEL. When the mimG gene was cloned and coexpressed with each mimABCD gene cluster in R. opacus strain B-4, this host successfully acquired oxidation activity towards phenol. SDS/PAGE and western blotting analyses demonstrated that MimA was clearly soluble when in the presence of MimG. These results indicated that MimG played essential roles in the productive folding of MimA, and that the resulting soluble MimA protein led to the active expression of MimABCD.
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Affiliation(s)
- Toshiki Furuya
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, Tokyo, Japan
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