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Chandel N, Singh BB, Dureja C, Yang YH, Bhatia SK. Indigo production goes green: a review on opportunities and challenges of fermentative production. World J Microbiol Biotechnol 2024; 40:62. [PMID: 38182914 DOI: 10.1007/s11274-023-03871-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 12/11/2023] [Indexed: 01/07/2024]
Abstract
Indigo is a widely used dye in various industries, such as textile, cosmetics, and food. However, traditional methods of indigo extraction and processing are associated with environmental and economic challenges. Fermentative production of indigo using microbial strains has emerged as a promising alternative that offers sustainability and cost-effectiveness. This review article provides a critical overview of microbial diversity, metabolic pathways, fermentation strategies, and genetic engineering approaches for fermentative indigo production. The advantages and limitations of different indigo production systems and a critique of the current understanding of indigo biosynthesis are discussed. Finally, the potential application of indigo in other sectors is also discussed. Overall, fermentative production of indigo offers a sustainable and bio-based alternative to synthetic methods and has the potential to contribute to the development of sustainable and circular biomanufacturing.
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Affiliation(s)
- Neha Chandel
- School of Medical and Allied Sciences, GD Goenka University, Gurugram, Haryana, 122103, India
| | - Bharat Bhushan Singh
- Department of Genomic Medicine, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Chetna Dureja
- Center for Inflammatory and Infectious Diseases, Texas A&M Health Science Center, Institute of Bioscience and Technology, Houston, TX, USA
| | - Yung-Hun Yang
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, 05029, Republic of Korea
- Institute for Ubiquitous Information Technology and Applications, Seoul, 05029, Republic of Korea
| | - Shashi Kant Bhatia
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, 05029, Republic of Korea.
- Institute for Ubiquitous Information Technology and Applications, Seoul, 05029, Republic of Korea.
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2
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Pan Z, Tao D, Ren M, Cheng L. A Combinational Optimization Method for Efficient Production of Indigo by the Recombinant Escherichia coli with Expression of Monooxygenase and Malate Dehydrogenase. Foods 2023; 12:foods12030502. [PMID: 36766031 PMCID: PMC9914922 DOI: 10.3390/foods12030502] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/16/2023] [Accepted: 01/19/2023] [Indexed: 01/24/2023] Open
Abstract
Indigo pigment is a widely used pigment, and the use of biosynthesis to ferment indigo has become a hot research topic. Based on previous research, the indigo could be biosynthesized via the styrene oxygenation pathway, which is regulated by intracellular redox-cofactor rebalancing. In this work, the malate dehydrogenase (mdh) gene was selected as an NADH regeneration element to improve the intracellular cofactor regeneration level, and it was co-expressed with the styrene monooxygenase (styAB) gene by pET-28a(+) vector in E. coli for enhancing indigo production. The PT7 and Pcat promoter was constructed to change the styAB gene and mdh gene from inducible expression to constitutive expression, since the expressing vector pET-28a(+) needs to be induced by IPTG. After different strategies of genetic manipulations, the styAB gene and mdh gene were successfully constitutively co-expressed by different promoters in E. coli, which obviously enhanced the monooxygenase activity and indigo production, as expected. The maximum yield of indigo in recombinant strains was up to 787.25 mg/L after 24 h of fermentation using 2.0 g/L tryptophan as substrate, which was nearly the highest indigo-producing ability using tryptophan as substrate in recent studies. In summary, this work provided a theoretical basis for the subsequent study of indigo biosynthesis and probably revealed a new insight into the construction of indigo biosynthesis cell factory for application.
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Affiliation(s)
| | | | | | - Lei Cheng
- Correspondence: ; Tel.: +86-10-68985252
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3
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Li F, Deng H, Zhong B, Ruan B, Zhao X, Luo X. Identification of an indole biodegradation gene cluster from Providencia rettgeri and its contribution in selectively biosynthesizing Tyrian purple. Front Bioeng Biotechnol 2023; 10:1109929. [PMID: 36704308 PMCID: PMC9871250 DOI: 10.3389/fbioe.2022.1109929] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 12/23/2022] [Indexed: 01/12/2023] Open
Abstract
Tyrian purple, mainly composed of 6, 6'-dibromoindigo, is a precious dye extracted from sea snails. In this study, we found Tyrian purple can be selectively produced by a bacterial strain GS-2 when fed with 6-bromotryptophan in the presence of tryptophan. This GS-2 strain was then identified as Providencia rettgeri based on bacterial genome sequencing analysis. An indole degradation gene cluster for indole metabolism was identified from this GS-2 strain. The heterologous expression of the indole degradation gene cluster in Escherichia coli BL21 (DE3) and in vitro enzymatic reaction demonstrated that the indole biodegradation gene cluster may contribute to selectively biosynthesizing Tyrian purple. To further explore the underlying mechanism of the selectivity, we explored the intermediates in this indole biodegradation pathway using liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS), which indicated that the indole biodegradation pathway in Providencia rettgeri is the catechol pathway. Interestingly, the monooxygenase GS-C co-expressed with its corresponding reductase GS-D in the cluster has better activity for the biosynthesis of Tyrian purple compared with the previously reported monooxygenase from Methylophaga aminisulfidivorans (MaFMO) or Streptomyces cattleya cytochrome P450 enzyme (CYP102G4). This is the first study to show the existence of an indole biodegradation pathway in Providencia rettgeri, and the indole biodegradation gene cluster can contribute to the selective production of Tyrian purple.
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Affiliation(s)
- Feifei Li
- School of Life Sciences, Inner Mongolia University, Hohhot, China,Shenzhen Key Laboratory for the Intelligent Microbial Manufacturing of Medicines, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,Center for Synthetic Biochemistry, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Huaxiang Deng
- Shenzhen Key Laboratory for the Intelligent Microbial Manufacturing of Medicines, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,Center for Synthetic Biochemistry, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Biming Zhong
- Shenzhen Key Laboratory for the Intelligent Microbial Manufacturing of Medicines, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,Center for Synthetic Biochemistry, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Banlai Ruan
- Shenzhen Key Laboratory for the Intelligent Microbial Manufacturing of Medicines, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,Center for Synthetic Biochemistry, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Xixi Zhao
- Shenzhen Key Laboratory for the Intelligent Microbial Manufacturing of Medicines, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,Center for Synthetic Biochemistry, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,*Correspondence: Xixi Zhao, ; Xiaozhou Luo,
| | - Xiaozhou Luo
- School of Life Sciences, Inner Mongolia University, Hohhot, China,Shenzhen Key Laboratory for the Intelligent Microbial Manufacturing of Medicines, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,Center for Synthetic Biochemistry, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,*Correspondence: Xixi Zhao, ; Xiaozhou Luo,
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Catucci G, Turella S, Cheropkina H, De Angelis M, Gilardi G, Sadeghi SJ. Green production of indigo and indirubin by an engineered Baeyer–Villiger monooxygenase. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Molecular and physiological analysis of indole-3-acetic acid degradation in Bradyrhizobium japonicum E109. Res Microbiol 2021; 172:103814. [PMID: 33539931 DOI: 10.1016/j.resmic.2021.103814] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/20/2021] [Accepted: 01/26/2021] [Indexed: 11/21/2022]
Abstract
Bradyrhizobium japonicum E109 is a bacterium widely used for inoculants production in Argentina. It is known for its ability to produce several phytohormones and degrade indole-3-acetic acid (IAA). The genome sequence of B. japonicum E109 was recently analyzed and it showed the presence of genes related to the synthesis of IAA by indole-3-acetonitrile, indole-3-acetamide and tryptamine pathways. Nevertheless, B. japonicum E109 is not able to produce IAA and instead has the ability to degrade this hormone under saprophytic culture conditions. This work aimed to study the molecular and physiological features of IAA degradation and identify the genes responsible of this activity. In B. japonicum E109 we identified two sequences coding for a putative 3-phenylpropionate dioxygenase (subunits α and β) responsible for the IAA degradation that were homologous to the canonical cluster of iacC and iacD of Pseudomonas putida 1290. These genes form a separate cluster together with three additional genes with unknown functions. The degradation activity was found to be constitutively expressed in B. japonicum E109. As products of IAA degradation, we identified two compounds, 3-indoleacetic acid 2,3-oxide and 2-(2-hydroperoxy-3-hydroxyindolin-3-yl) acetic acid. Our report proposes, for the first time, a model for IAA degradation in Bradyrhizobium.
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Vaidya SS, Patel AB, Jain K, Amin S, Madamwar D. Characterizing the bacterial consortium ASDF capable of catabolic degradation of fluoranthene and other mono- and poly-aromatic hydrocarbons. 3 Biotech 2020; 10:491. [PMID: 33134009 DOI: 10.1007/s13205-020-02478-w] [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: 06/02/2020] [Accepted: 10/12/2020] [Indexed: 10/23/2022] Open
Abstract
In this study, a bacterial consortium ASDF was developed, capable of degrading fluoranthene (a non-alternant poly-aromatic hydrocarbon). It comprised of three bacterial strains: Pseudomonas sp. ASDF1, Burkholderia sp. ASDF2 and Mycobacterium sp. ASDF3 capable of degrading 100 mg/L of fluoranthene under experimentally defined and optimum conditions (37 °C, pH 7.0, 150 rpm) within 7 days. Consortium had metabolized fluoranthene as sole source of carbon and energy with maximum degradation rate of 0.52 mg/L/h and growth rate of 0.054/h. Fluoranthene degradation is an aerobic process, therefore with increasing the gyratory shaking from 50 to 150 rpm, degradation was concurrently enhanced by 7.1-fold. The synthetic surfactants SDS and CTAB had antagonistic effect on fluoranthene degradation (decreased up to 2.8-fold). The proficiency of consortium was assessed for its inherent ability to degrade seven other hydrocarbons both individually as well as in mixture. The degradation profile was studied using HPLC and the detection of two degraded intermediates (salicylic acid and derivatives of phthalic acid) suggested that fluoranthene degradation might have occurred via ortho- and meta-cleavage pathways. The competency of consortium was further validated through simulated microcosm studies, which showed 96% degradation of fluoranthene in soil ecosystem under the ambient conditions. Hence, the study suggested that the consortium ASDF has an inherent potential for its wide applicability in bioremediation of hydrocarbon-contaminated sites.
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Affiliation(s)
- Sagar S Vaidya
- Post Graduate Department of Biosciences, UGC Centre of Advanced Study, Satellite Campus, Vadtal Road, Sardar Patel University, Bakrol, Anand, Gujarat 388 315 India
| | - Avani Bharatkumar Patel
- Post Graduate Department of Biosciences, UGC Centre of Advanced Study, Satellite Campus, Vadtal Road, Sardar Patel University, Bakrol, Anand, Gujarat 388 315 India
| | - Kunal Jain
- Post Graduate Department of Biosciences, UGC Centre of Advanced Study, Satellite Campus, Vadtal Road, Sardar Patel University, Bakrol, Anand, Gujarat 388 315 India
| | - Seema Amin
- P. D. Patel Institute of Applied Sciences, Charotar University of Science and Technology, Charusat Campus, Changa, Anand, Gujarat 388 421 India
| | - Datta Madamwar
- Post Graduate Department of Biosciences, UGC Centre of Advanced Study, Satellite Campus, Vadtal Road, Sardar Patel University, Bakrol, Anand, Gujarat 388 315 India.,P. D. Patel Institute of Applied Sciences, Charotar University of Science and Technology, Charusat Campus, Changa, Anand, Gujarat 388 421 India
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7
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Fabara AN, Fraaije MW. An overview of microbial indigo-forming enzymes. Appl Microbiol Biotechnol 2019; 104:925-933. [PMID: 31834440 PMCID: PMC6962290 DOI: 10.1007/s00253-019-10292-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/23/2019] [Accepted: 11/28/2019] [Indexed: 11/03/2022]
Abstract
Indigo is one of the oldest textile dyes and was originally prepared from plant material. Nowadays, indigo is chemically synthesized at a large scale to satisfy the demand for dyeing jeans. The current indigo production processes are based on fossil feedstocks; therefore, it is highly attractive to develop a more sustainable and environmentally friendly biotechnological process for the production of this popular dye. In the past decades, a number of natural and engineered enzymes have been identified that can be used for the synthesis of indigo. This mini-review provides an overview of the various microbial enzymes which are able to produce indigo and discusses the advantages and disadvantages of each biocatalytic system.
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Affiliation(s)
- Andrea N Fabara
- Molecular Enzymology group, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Marco W Fraaije
- Molecular Enzymology group, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
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Ma Q, Zhang X, Qu Y. Biodegradation and Biotransformation of Indole: Advances and Perspectives. Front Microbiol 2018; 9:2625. [PMID: 30443243 PMCID: PMC6221969 DOI: 10.3389/fmicb.2018.02625] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 10/15/2018] [Indexed: 11/17/2022] Open
Abstract
Indole is long regarded as a typical N-heterocyclic aromatic pollutant in industrial and agricultural wastewater, and recently it has been identified as a versatile signaling molecule with wide environmental distributions. An exponentially growing number of researches have been reported on indole due to its significant roles in bacterial physiology, pathogenesis, animal behavior and human diseases. From the viewpoint of both environmental bioremediation and biological studies, the researches on metabolism and fates of indole are important to realize environmental treatment and illuminate its biological function. Indole can be produced from tryptophan by tryptophanase in many bacterial species. Meanwhile, various bacterial strains have obtained the ability to transform and degrade indole. The characteristics and pathways for indole degradation have been investigated for a century, and the functional genes for indole aerobic degradation have also been uncovered recently. Interestingly, many oxygenases have proven to be able to oxidize indole to indigo, and this historic and motivating case for biological applications has attracted intensive attention for decades. Herein, the bacteria, enzymes and pathways for indole production, biodegradation and biotransformation are systematically summarized, and the future researches on indole-microbe interactions are also prospected.
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Affiliation(s)
- Qiao Ma
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, China
| | - Xuwang Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Food and Environment, Dalian University of Technology, Panjin, China
| | - Yuanyuan Qu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
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9
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Kugel S, Baunach M, Baer P, Ishida-Ito M, Sundaram S, Xu Z, Groll M, Hertweck C. Cryptic indole hydroxylation by a non-canonical terpenoid cyclase parallels bacterial xenobiotic detoxification. Nat Commun 2017. [PMID: 28643772 PMCID: PMC5481743 DOI: 10.1038/ncomms15804] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Terpenoid natural products comprise a wide range of molecular architectures that typically result from C–C bond formations catalysed by classical type I/II terpene cyclases. However, the molecular diversity of biologically active terpenoids is substantially increased by fully unrelated, non-canonical terpenoid cyclases. Their evolutionary origin has remained enigmatic. Here we report the in vitro reconstitution of an unusual flavin-dependent bacterial indoloterpenoid cyclase, XiaF, together with a designated flavoenzyme-reductase (XiaP) that mediates a key step in xiamycin biosynthesis. The crystal structure of XiaF with bound FADH2 (at 2.4 Å resolution) and phylogenetic analyses reveal that XiaF is, surprisingly, most closely related to xenobiotic-degrading enzymes. Biotransformation assays show that XiaF is a designated indole hydroxylase that can be used for the production of indigo and indirubin. We unveil a cryptic hydroxylation step that sets the basis for terpenoid cyclization and suggest that the cyclase has evolved from xenobiotics detoxification enzymes. The biosynthesis of xiamycin, an antimicrobial bacterial indolosesquiterpenoid, involves an unusual cyclization cascade. Here, the authors characterise the XiaF enzyme, which resembles xenobiont-degrading enzymes and is responsible for a hidden indole hydroxylation step that triggers the cyclization reaction.
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Affiliation(s)
- Susann Kugel
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Martin Baunach
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Philipp Baer
- Center for Integrated Protein Science Munich (CIPSM), Department Chemie, Technische Universität München, Lichtenbergstr. 4, 85748 Garching, Germany
| | - Mie Ishida-Ito
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Srividhya Sundaram
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Zhongli Xu
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Michael Groll
- Center for Integrated Protein Science Munich (CIPSM), Department Chemie, Technische Universität München, Lichtenbergstr. 4, 85748 Garching, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745 Jena, Germany.,Natural Product Chemistry, Friedrich Schiller University, 07743 Jena, Germany
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10
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Lin GH, Chen HP, Shu HY. Detoxification of Indole by an Indole-Induced Flavoprotein Oxygenase from Acinetobacter baumannii. PLoS One 2015; 10:e0138798. [PMID: 26390211 PMCID: PMC4577076 DOI: 10.1371/journal.pone.0138798] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 09/03/2015] [Indexed: 11/17/2022] Open
Abstract
Indole, a derivative of the amino acid tryptophan, is a toxic signaling molecule, which can inhibit bacterial growth. To overcome indole-induced toxicity, many bacteria have developed enzymatic defense systems to convert indole to non-toxic, water-insoluble indigo. We previously demonstrated that, like other aromatic compound-degrading bacteria, Acinetobacter baumannii can also convert indole to indigo. However, no work has been published investigating this mechanism. Here, we have shown that the growth of wild-type A. baumannii is severely inhibited in the presence of 3.5 mM indole. However, at lower concentrations, growth is stable, implying that the bacteria may be utilizing a survival mechanism to oxidize indole. To this end, we have identified a flavoprotein oxygenase encoded by the iifC gene of A. baumannii. Further, our results suggest that expressing this recombinant oxygenase protein in Escherichia coli can drive indole oxidation to indigo in vitro. Genome analysis shows that the iif operon is exclusively present in the genomes of A. baumannii and Pseudomonas syringae pv. actinidiae. Quantitative PCR and Western blot analysis also indicate that the iif operon is activated by indole through the AraC-like transcriptional regulator IifR. Taken together, these data suggest that this species of bacteria utilizes a novel indole-detoxification mechanism that is modulated by IifC, a protein that appears to be, at least to some extent, regulated by IifR.
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Affiliation(s)
- Guang-Huey Lin
- Microbial Genetics Laboratory, Department of Microbiology, Tzu-Chi University, Hualien, Taiwan
| | - Hao-Ping Chen
- Department of Biochemistry, School of Medicine, Tzu-Chi University, Hualien, Taiwan
| | - Hung-Yu Shu
- Department of Bioscience Technology, Chang Jung Christian University, Tainan, Taiwan
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11
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Identification of benzo[a]pyrene-metabolizing bacteria in forest soils by using DNA-based stable-isotope probing. Appl Environ Microbiol 2015; 81:7368-76. [PMID: 26253666 DOI: 10.1128/aem.01983-15] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 08/02/2015] [Indexed: 01/21/2023] Open
Abstract
DNA-based stable-isotope probing (DNA-SIP) was used in this study to investigate the uncultivated bacteria with benzo[a]pyrene (BaP) metabolism capacities in two Chinese forest soils (Mt. Maoer in Heilongjiang Province and Mt. Baicaowa in Hubei Province). We characterized three different phylotypes with responsibility for BaP degradation, none of which were previously reported as BaP-degrading microorganisms by SIP. In Mt. Maoer soil microcosms, the putative BaP degraders were classified as belonging to the genus Terrimonas (family Chitinophagaceae, order Sphingobacteriales), whereas Burkholderia spp. were the key BaP degraders in Mt. Baicaowa soils. The addition of metabolic salicylate significantly increased BaP degradation efficiency in Mt. Maoer soils, and the BaP-metabolizing bacteria shifted to the microorganisms in the family Oxalobacteraceae (genus unclassified). Meanwhile, salicylate addition did not change either BaP degradation or putative BaP degraders in Mt. Baicaowa. Polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHD) genes were amplified, sequenced, and quantified in the DNA-SIP (13)C heavy fraction to further confirm the BaP metabolism. By illuminating the microbial diversity and salicylate additive effects on BaP degradation across different soils, the results increased our understanding of BaP natural attenuation and provided a possible approach to enhance the bioremediation of BaP-contaminated soils.
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12
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Cao J, Lai Q, Yuan J, Shao Z. Genomic and metabolic analysis of fluoranthene degradation pathway in Celeribacter indicus P73T. Sci Rep 2015; 5:7741. [PMID: 25582347 PMCID: PMC4291564 DOI: 10.1038/srep07741] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 11/20/2014] [Indexed: 01/22/2023] Open
Abstract
Celeribacter indicus P73(T), isolated from deep-sea sediment from the Indian Ocean, is capable of degrading a wide range of polycyclic aromatic hydrocarbons (PAHs) and is the first fluoranthene-degrading bacterium within the family Rhodobacteraceae. Here, the complete genome sequence of strain P73(T) is presented and analyzed. Besides a 4.5-Mb circular chromosome, strain P73(T) carries five plasmids, and encodes 4827 predicted protein-coding sequences. One hundred and thirty-eight genes, including 14 dioxygenase genes, were predicted to be involved in the degradation of aromatic compounds, and most of these genes are clustered in four regions. P73_0346 is the first fluoranthene 7,8-dioxygenase to be discovered and the first fluoranthene dioxygenase within the toluene/biphenyl family. The degradative genes in regions B and D in P73(T) are absent in Celeribacter baekdonensis B30, which cannot degrade PAHs. Four intermediate metabolites [acenaphthylene-1(2H)-one, acenaphthenequinone, 1,2-dihydroxyacenaphthylene, and 1,8-naphthalic anhydride] of fluoranthene degradation by strain P73(T) were detected as the main intermediates, indicating that the degradation of fluoranthene in P73(T) was initiated by dioxygenation at the C-7,8 positions. Based on the genomic and metabolitic results, we propose a C-7,8 dioxygenation pathway in which fluoranthene is mineralized to TCA cycle intermediates.
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Affiliation(s)
- Junwei Cao
- State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, The Third Institute of State Oceanic Administration; Key Laboratory of Marine Genetic Resources of Fujian Province; Collaborative Innovation Center of Deep Sea Biology; Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen 361005, China
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Qiliang Lai
- State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, The Third Institute of State Oceanic Administration; Key Laboratory of Marine Genetic Resources of Fujian Province; Collaborative Innovation Center of Deep Sea Biology; Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen 361005, China
| | - Jun Yuan
- State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, The Third Institute of State Oceanic Administration; Key Laboratory of Marine Genetic Resources of Fujian Province; Collaborative Innovation Center of Deep Sea Biology; Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen 361005, China
| | - Zongze Shao
- State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, The Third Institute of State Oceanic Administration; Key Laboratory of Marine Genetic Resources of Fujian Province; Collaborative Innovation Center of Deep Sea Biology; Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen 361005, China
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13
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Jadeja NB, More RP, Purohit HJ, Kapley A. Metagenomic analysis of oxygenases from activated sludge. BIORESOURCE TECHNOLOGY 2014; 165:250-256. [PMID: 24631150 DOI: 10.1016/j.biortech.2014.02.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 06/03/2023]
Abstract
Oxygenases play a key role in degradation of the aromatic compounds in the wastewater. This study explores the oxygenase coding gene sequences from the metagenome of activated biomass. Based on these results, the catabolic capacity of the activated sludge was assessed towards degradation of naphthalene, anthracene, phenol, biphenyl and o-toluidine. Oxygenases found in this study were compared with oxygenases from three other metagenome datasets. Results demonstrate that despite different geographical locations and source, many genes coding for oxygenases were common between treatment plants. 1, 2 Homogentisate dioxygenase and phenylacetate CoA oxygenases were present in all four metagenomes. Metagenomics provides a vast amount of data that needs to be mined with specific targets to harness the potential of the microbial world.
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Affiliation(s)
- Niti B Jadeja
- Environmental Genomics Division, National Environmental Engineering Research Institute, (CSIR-NEERI), Nehru Marg, Nagpur 440 020, India
| | - Ravi P More
- Environmental Genomics Division, National Environmental Engineering Research Institute, (CSIR-NEERI), Nehru Marg, Nagpur 440 020, India
| | - Hemant J Purohit
- Environmental Genomics Division, National Environmental Engineering Research Institute, (CSIR-NEERI), Nehru Marg, Nagpur 440 020, India
| | - Atya Kapley
- Environmental Genomics Division, National Environmental Engineering Research Institute, (CSIR-NEERI), Nehru Marg, Nagpur 440 020, India.
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Duca D, Lorv J, Patten CL, Rose D, Glick BR. Indole-3-acetic acid in plant-microbe interactions. Antonie van Leeuwenhoek 2014; 106:85-125. [PMID: 24445491 DOI: 10.1007/s10482-013-0095-y] [Citation(s) in RCA: 325] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 12/07/2013] [Indexed: 01/04/2023]
Abstract
Indole-3-acetic acid (IAA) is an important phytohormone with the capacity to control plant development in both beneficial and deleterious ways. The ability to synthesize IAA is an attribute that many bacteria including both plant growth-promoters and phytopathogens possess. There are three main pathways through which IAA is synthesized; the indole-3-pyruvic acid, indole-3-acetamide and indole-3-acetonitrile pathways. This chapter reviews the factors that effect the production of this phytohormone, the role of IAA in bacterial physiology and in plant-microbe interactions including phytostimulation and phytopathogenesis.
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Affiliation(s)
- Daiana Duca
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada,
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15
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Functional characterization of the bacterial iac genes for degradation of the plant hormone indole-3-acetic acid. J Chem Ecol 2013; 39:942-51. [PMID: 23881445 DOI: 10.1007/s10886-013-0324-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Revised: 06/29/2013] [Accepted: 07/04/2013] [Indexed: 10/26/2022]
Abstract
Pseudomonas putida 1290 is a model organism for the study of bacterial degradation of the plant hormone indole-3-acetic acid (IAA). This property is encoded by the iac gene cluster. Insertional inactivation and/or deletion of individual iac genes and heterologous expression of the gene cluster in Escherichia coli were combined with mass spectrometry to demonstrate that iac-based degradation of IAA is likely to involve 2-hydroxy-IAA, 3-hydroxy-2-oxo-IAA, and catechol as intermediates. The first gene of the cluster, iacA encodes for the first step in the pathway, and also can convert indole to indoxyl to produce the blue pigment indigo. Transcriptional profiling of iac genes in P. putida 1290 revealed that they were induced in the presence of IAA. Based on results with an iacR knockout, we propose that this gene codes for a repressor of iacA expression and that exposure to IAA relieves this repression. Transformation of P. putida KT2440 (which cannot degrade IAA) with the iac gene cluster conferred the ability to grow on IAA as a sole source of carbon and energy, but not the ability to chemotaxi towards IAA. We could show such tactic response for P. putida 1290, thus representing the first demonstration of bacterial chemotaxis towards IAA. We discuss the ecological significance of our findings, and specifically the following question: under what circumstances do bacteria with the ability to degrade, recognize, and move towards IAA have a selective advantage?
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16
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Kim JG, Jung MY, Park SJ, Rijpstra WIC, Sinninghe Damsté JS, Madsen EL, Min D, Kim JS, Kim GJ, Rhee SK. Cultivation of a highly enriched ammonia-oxidizing archaeon of thaumarchaeotal group I.1b from an agricultural soil. Environ Microbiol 2012; 14:1528-43. [PMID: 22515152 DOI: 10.1111/j.1462-2920.2012.02740.x] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nitrification of excess ammonia in soil causes eutrophication of water resources and emission of atmospheric N(2) O gas. The first step of nitrification, ammonia oxidation, is mediated by Archaea as well as Bacteria. The physiological reactions mediated by ammonia-oxidizing archaea (AOA) and their contribution to soil nitrification are still unclear. Results of non-culture-based studies have shown the thaumarchaeotal group I.1b lineage of AOA to be dominant over both AOA of group I.1a and ammonia-oxidizing bacteria in various soils. We obtained from an agricultural soil a highly enriched ammonia-oxidizing culture dominated by a single archaeal population [c. 90% of total cells, as determined microscopically (by fluorescence in situ hybridization) and by quantitative PCR of its 16S rRNA gene]. The archaeon (termed 'strain JG1') fell within thaumarchaeotal group I.1b and was related to the moderately thermophilic archaeon, Candidatus Nitrososphaera gargensis, and the mesophilic archaeon, Ca. Nitrososphaera viennensis with 97.0% and 99.1% 16S rRNA gene sequence similarity respectively. Strain JG1 was neutrophilic (growth range pH 6.0-8.0) and mesophilic (growth range temperature 25-40°C). The optimum temperature of strain JG1 (35-40°C) is > 10°C higher than that of ammonia-oxidizing bacteria (AOB). Membrane analysis showed that strain JG1 contained a glycerol dialkyl glycerol tetraether, GDGT-4, and its regioisomer as major core lipids; this crenarchaeol regioisomer was previously detected in similar abundance in the thermophile, Ca. N. gargensis and has been frequently observed in tropical soils. Substrate uptake assays showed that the affinity of strain JG1 for ammonia and oxygen was much higher than those of AOB. These traits may give a competitive advantage to AOA related to strain JG1 in oligotrophic environments. (13) C-bicarbonate incorporation into archaeal lipids of strain JG1 established its ability to grow autotrophically. Strain JG1 produced a significant amount of N(2) O gas - implicating AOA as a possible source of N(2) O emission from soils. Sequences of archaeal amoA and 16S rRNA genes closely related to those of strain JG1 have been retrieved from various terrestrial environments in which lineage of strain JG1 is likely engaged in autotrophic nitrification.
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Affiliation(s)
- Jong-Geol Kim
- Department of Microbiology, Chungbuk National University, 12 Gaeshin-dong, Heungduk-gu, Cheongju, Korea
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Lin GH, Chen HP, Huang JH, Liu TT, Lin TK, Wang SJ, Tseng CH, Shu HY. Identification and characterization of an indigo-producing oxygenase involved in indole 3-acetic acid utilization by Acinetobacter baumannii. Antonie van Leeuwenhoek 2012; 101:881-90. [DOI: 10.1007/s10482-012-9704-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Accepted: 01/21/2012] [Indexed: 01/01/2023]
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18
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Mouri T, Kamiya N, Goto M. New strategy to enhance catalytic performance of Escherichia coli whole cell biocatalysts harboring P450cam mutants. Biochem Eng J 2011. [DOI: 10.1016/j.bej.2010.09.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Yuan J, Lai Q, Zheng T, Shao Z. Novosphingobium indicum sp. nov., a polycyclic aromatic hydrocarbon-degrading bacterium isolated from a deep-sea environment. Int J Syst Evol Microbiol 2009; 59:2084-8. [DOI: 10.1099/ijs.0.002873-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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20
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Powell SN, Singleton DR, Aitken MD. Effects of enrichment with salicylate on bacterial selection and PAH mineralization in a microbial community from a bioreactor treating contaminated soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:4099-4105. [PMID: 18589972 DOI: 10.1021/es703007n] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We investigated enrichment with salicylate as a method to stimulate the degradation of polycyclic aromatic hydrocarbons (PAHs) by a microbial communityfrom a bioreactortreating PAH-contaminated soil. DNA-based stable isotope probing (SIP) was used to compare the effect of alternate methods of salicylate addition (spike vs slow, continuous addition) on the diversity of the enriched microbial community. After identification of salicylate degraders by SIP, real-time quantitative PCR (qPCR) primers were developed to quantify the abundances of three groups containing salicylate-utilizing organisms in the bioreactor community before and after enrichment. The different methods of salicylate addition were found to select for different microbial communities. Two groups containing salicylate-degrading bacteria increased in abundance substantially after enrichment by continuous addition of salicylate but did not increase in abundance in response to the spike addition, whereas a third group increased in abundance in response to both methods of salicylate addition. The initial rate of naphthalene mineralization increased significantly after enrichment by spike addition of salicylate, but neither phenanthrene nor benzo[a] pyrene mineralization rates were enhanced. Continuous addition of salicylate did not enhance the mineralization rate for any of the PAHs. These results suggest that enrichment with salicylate can select for naphthalene-degrading bacteria, but does not select for organisms responsible for degrading PAHs of higher molecular weight. Differences in microbial selection observed in this study that resulted from different rates of carbon source addition also have implications for the design of SIP experiments with water-soluble carbon sources.
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Affiliation(s)
- Sabrina N Powell
- Department of Environmental Sciences and Engineering, School of Public Health, CB#7431, 166 Rosenau Hall, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7431, USA
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Leveau JHJ, Gerards S. Discovery of a bacterial gene cluster for catabolism of the plant hormone indole 3-acetic acid. FEMS Microbiol Ecol 2008; 65:238-50. [PMID: 18205812 DOI: 10.1111/j.1574-6941.2008.00436.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The isolation and annotation of an 8994-bp DNA fragment from Pseudomonas putida 1290, which conferred upon P. putida KT2440 the ability to utilize the plant hormone indole 3-acetic acid (IAA) as a sole source of carbon and energy, is described. This iac locus (for indole 3-acetic acid catabolism) was identified through analysis of a plasposon mutant of P. putida 1290 that was no longer able to grow on IAA or indole 3-acetaldehyde and was unable to protect radish roots from stunting by exogenously added IAA. The iac locus consisted of 10 genes with coding similarity to enzymes acting on indole or amidated aromatics and to proteins with regulatory or unknown function. Highly similar iac gene clusters were identified in the genomes of 22 bacterial species. Five of these, i.e. P. putida GB-1, Marinomonas sp. MWYL1, Burkholderia sp. 383, Sphingomonas wittichii RW1 and Rhodococcus sp. RHA1, were tested to confirm that bacteria with IAA-degrading ability have representatives in the Alpha-, Beta- and Gammaproteobacteria and in the Actinobacteria. In P. putida 1290, cat and pca genes were found to be essential to IAA-degradation, suggesting that IAA is channeled via catechol into the beta-ketoadipate pathway. Also contributing to the IAA degrading phenotype were genes involved in tricarboxylate cycling, gluconeogenesis, and carbon/nitrogen sensing.
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Affiliation(s)
- Johan H J Leveau
- Netherlands Institute of Ecology (NIOO-KNAW), Heteren, The Netherlands.
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22
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Ben Said O, Goñi-Urriza MS, El Bour M, Dellali M, Aissa P, Duran R. Characterization of aerobic polycyclic aromatic hydrocarbon-degrading bacteria from Bizerte lagoon sediments, Tunisia. J Appl Microbiol 2007; 104:987-97. [PMID: 17973912 DOI: 10.1111/j.1365-2672.2007.03621.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To characterize polycyclic aromatic hydrocarbon (PAH)-degrading bacteria from sediments of the Bizerte lagoon, and to determine their ability to resist other pollutants such as antibiotics and heavy metals. METHODS AND RESULTS More than 100 strains were isolated for their ability to use fluoranthene as the sole carbon and energy source. Most of them showed antibiotic and heavy metal resistance; 20 representative strains were selected for further analysis. 16S rRNA coding sequences analysis showed that the majority of the selected bacteria (75%) were affiliated to the Gammaproteobacteria. The selected strains also utilized high molecular weight PAHs containing up to four benzene rings and showed different profiles of PAH substrate usage suggesting different PAH degradation pathways. These results are consistent with the fact that nah-like genes and idoA-like genes, involved in PAH degradation, were detected in 6 and 1 strains respectively. CONCLUSIONS The Bizerte lagoon, polluted by many human activities, leads to the co-selection of strains able to cope with multiple contaminants. SIGNIFICANCE AND IMPACT OF THE STUDY Polluted areas are often characterized by the concomitant presence of organic pollutants, heavy metals and antibiotics. This study is one of the first showing bacterial strains adapted to multiple contaminants, a promising potential for the development of bioremediation processes.
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Affiliation(s)
- O Ben Said
- Equipe Environnement et Microbiologie, IPREM UMR 5254, IBEAS, Université de Pau et des Pays de l'Adour, Pau Cedex, France
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Kapley A, De Baere T, Purohit HJ. Eubacterial diversity of activated biomass from a common effluent treatment plant. Res Microbiol 2007; 158:494-500. [PMID: 17566710 DOI: 10.1016/j.resmic.2007.04.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2007] [Accepted: 04/13/2007] [Indexed: 10/23/2022]
Abstract
A common effluent treatment plant (CETP) is a biological wastewater treatment facility that receives wastewater from different industries. The activated biomass in the CETP survives on a wide range of chemicals with no fixed wastewater characteristics. We carried out a diversity analysis of this activated biomass using culture as well as culture-independent techniques. Using culture-based techniques, strains belonging to 26 different genera from the phyla Proteobacteria, Actinobacteria and Firmicutes were isolated. The gamma-proteobacteria was the best represented class, with 36.5% of the isolates. Bacterial diversity was also analyzed culture-independently by means of sequence determination of cloned 16S rRNA genes. Twenty-one different genera from the phyla Proteobacteria, Firmicutes, Planctomycetes and Bacteroidetes were identified. The total diversity of the activated biomass was composed of members of five known phyla, represented by 37 genera, with the Proteobacteria constituting the most abundant phylum detected. However, a very large fraction of the diversity represented a hitherto unidentified bacterial population. More than half (50.2%) of the 16S rDNA clones represented unidentified non-culturable bacteria, underlining the vast untapped diversity of CETP communities. Our results also indicate that both culture-based and culture-independent techniques should be combined to cover the microbial diversity of complex ecosystems.
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Affiliation(s)
- Atya Kapley
- Environmental Genomics Unit, National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440 020, India
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Production of Indigo by Immobilization of E. coli BL21 (DE3) Cells in Calcium-Alginate Gel Capsules. Chin J Chem Eng 2007. [DOI: 10.1016/s1004-9541(07)60096-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Lu Y, Mei L. Co-expression of P450 BM3 and glucose dehydrogenase by recombinant Escherichia coli and its application in an NADPH-dependent indigo production system. J Ind Microbiol Biotechnol 2006; 34:247-53. [PMID: 17171348 DOI: 10.1007/s10295-006-0193-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Accepted: 11/15/2006] [Indexed: 10/23/2022]
Abstract
P450 BM3 mutant can catalyze indole to indoxyl, and indoxyl can dimerize to form indigo. But the reaction catalyzed by P450 BM3 requires NADPH, as coenzyme regeneration is very important in this system. As we know, when glucose dehydrogenase oxidizes glucose to glucolactone, NADH or NADPH can be formed, which can contribute to NADPH regeneration in the reaction catalyzed by P450 BM3. In this paper, a recombinant Escherichia coli BL21 (pET28a (+)-P450 BM3-gdh0310) was constructed to co-express both P450 BM3 gene and glucose dehydrogenase (GDH) gene. To improve the expression level of P450 BM3 and GDH in E. coli and to avoid the complex and low-efficiency refolding operation in the purification procedure, the expression conditions were optimized. Under the optimized conditions, the maximum P450 BM3 and GDH activities amounted to 8173.13 and 0.045 U/mg protein, respectively. Then bioconversion of indole to indigo was carried out by adding indole and glucose to the culture after improved expression level was obtained under optimized conditions, and 2.9 mM (760.6 mg/L) indigo was formed with an initial indole concentration of 5 mM.
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Affiliation(s)
- Yan Lu
- Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
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26
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O'Mahony MM, Dobson ADW, Barnes JD, Singleton I. The use of ozone in the remediation of polycyclic aromatic hydrocarbon contaminated soil. CHEMOSPHERE 2006; 63:307-14. [PMID: 16153687 DOI: 10.1016/j.chemosphere.2005.07.018] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Revised: 06/24/2005] [Accepted: 07/10/2005] [Indexed: 05/04/2023]
Abstract
The potential of using ozone for the removal of phenanthrene from several different soils, both alone and in combination with biodegradation using a microbial inoculant (Pseudomonas alcaligenes PA-10), was examined. The greater the water content of the soil the less effective the ozone treatment, with air-dried soils showing the greatest removal of phenanthrene; while soils with higher levels of clay also reduced the effectiveness of the ozone treatments. However, at least a 50% reduction in phenanthrene levels was achieved in air-dried soil after an ozone treatment of 6 h at 20 ppm, with up to 85% removal of phenanthrene achieved in sandy soils. The biodegradation results indicate that P. alcaligenes PA-10 may be useful as an inoculant for the removal of PAHs from contaminated soils. Under the conditions used in our experiments, however, pre-ozonation did not enhance subsequent biodegradation of phenanthrene in the soils. Similar levels of phenanthrene removal occurred in both non-ozonated and ozonated Cruden Bay soil inoculated with P. alcaligenes PA-10. However, the biodegradation of phenanthrene in ozonated Boyndie soil was much slower. This may be due to the release of toxic products in this soil during ozonation.
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Affiliation(s)
- Mark M O'Mahony
- Department of Microbiology, Environmental Research Institute, University College Cork, National University of Ireland, Cork, Ireland
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