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Varshney S, Bhattacharya A, Gupta A. Halo-alkaliphilic microbes as an effective tool for heavy metal pollution abatement and resource recovery: challenges and future prospects. 3 Biotech 2023; 13:400. [PMID: 37982082 PMCID: PMC10651602 DOI: 10.1007/s13205-023-03807-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 10/10/2023] [Indexed: 11/21/2023] Open
Abstract
The current study presents an overview of heavy metals bioremediation from halo-alkaline conditions by using extremophilic microorganisms. Heavy metal remediation from the extreme environment with high pH and elevated salt concentration is a challenge as mesophilic microorganisms are unable to thrive under these polyextremophilic conditions. Thus, for effective bioremediation of extreme systems, specialized microbes (extremophiles) are projected as potential bioremediating agents, that not only thrive under such extreme conditions but are also capable of remediating heavy metals from these environments. The physiological versatility of extremophiles especially halophiles and alkaliphiles and their enzymes (extremozymes) could conveniently be harnessed to remediate and detoxify heavy metals from the high alkaline saline environment. Bibliometric analysis has shown that research in this direction has found pace in recent years and thus this review is a timely attempt to highlight the importance of halo-alkaliphiles for effective contaminant removal in extreme conditions. Also, this review systematically presents insights on adaptive measures utilized by extremophiles to cope with harsh environments and outlines the role of extremophilic microbes in industrial wastewater treatment and recovery of metals from waste with relevant examples. Further, the major challenges and way forward for the effective applicability of halo-alkaliphilic microbes in heavy metals bioremediation from extremophilic conditions are also highlighted.
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Affiliation(s)
- Shipra Varshney
- University School of Environment Management, Guru Gobind Singh Indraprastha University, Sector-16C, Dwarka, New Delhi, 110078 India
| | - Amrik Bhattacharya
- Enzyme and Microbial Biochemistry Lab, Department of Chemistry, Indian Institute of Technology Delhi, Hauz-Khas, New Delhi, 110016 India
- Amity Institute of Environmental Sciences, Amity University, Noida, Uttar Pradesh 201313 India
| | - Anshu Gupta
- University School of Environment Management, Guru Gobind Singh Indraprastha University, Sector-16C, Dwarka, New Delhi, 110078 India
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Madigan MT, Bender KS, Sanguedolce SA, Parenteau MN, Mayer MH, Kimura Y, Wang-Otomo ZY, Sattley WM. Genomic basis for the unique phenotype of the alkaliphilic purple nonsulfur bacterium Rhodobaca bogoriensis. Extremophiles 2023; 27:19. [PMID: 37481751 DOI: 10.1007/s00792-023-01304-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 07/14/2023] [Indexed: 07/25/2023]
Abstract
Although several species of purple sulfur bacteria inhabit soda lakes, Rhodobaca bogoriensis is the first purple nonsulfur bacterium cultured from such highly alkaline environments. Rhodobaca bogoriensis strain LBB1T was isolated from Lake Bogoria, a soda lake in the African Rift Valley. The phenotype of Rhodobaca bogoriensis is unique among purple bacteria; the organism is alkaliphilic but not halophilic, produces carotenoids absent from other purple nonsulfur bacteria, and is unable to grow autotrophically or fix molecular nitrogen. Here we analyze the draft genome sequence of Rhodobaca bogoriensis to gain further insight into the biology of this extremophilic purple bacterium. The strain LBB1T genome consists of 3.91 Mbp with no plasmids. The genome sequence supports the defining characteristics of strain LBB1T, including its (1) production of a light-harvesting 1-reaction center (LH1-RC) complex but lack of a peripheral (LH2) complex, (2) ability to synthesize unusual carotenoids, (3) capacity for both phototrophic (anoxic/light) and chemotrophic (oxic/dark) energy metabolisms, (4) utilization of a wide variety of organic compounds (including acetate in the absence of a glyoxylate cycle), (5) ability to oxidize both sulfide and thiosulfate despite lacking the capacity for autotrophic growth, and (6) absence of a functional nitrogen-fixation system for diazotrophic growth. The assortment of properties in Rhodobaca bogoriensis has no precedent among phototrophic purple bacteria, and the results are discussed in relation to the organism's soda lake habitat and evolutionary history.
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Affiliation(s)
- Michael T Madigan
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Kelly S Bender
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Sophia A Sanguedolce
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Mary N Parenteau
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Marisa H Mayer
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Yukihiro Kimura
- Department of Agrobioscience, Kobe University, Kobe, 657-8501, Japan
| | | | - W Matthew Sattley
- Division of Natural Sciences, Indiana Wesleyan University, Marion, IN, 46953, USA.
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Demirkaya C, Vadlamani A, Tervahauta T, Strous M, De la Hoz Siegler H. Autofermentation of alkaline cyanobacterial biomass to enable biorefinery approach. Biotechnol Biofuels Bioprod 2023; 16:62. [PMID: 37029442 PMCID: PMC10082510 DOI: 10.1186/s13068-023-02311-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 03/28/2023] [Indexed: 04/09/2023]
Abstract
BACKGROUND Carbon capture using alkaliphilic cyanobacteria can be an energy-efficient and environmentally friendly process for producing bioenergy and bioproducts. The inefficiency of current harvesting and downstream processes, however, hinders large-scale feasibility. The high alkalinity of the biomass also introduces extra challenges, such as potential corrosion, inhibitory effects, or contamination of the final products. Thus, it is critical to identify low cost and energy-efficient downstream processes. RESULTS Autofermentation was investigated as an energy-efficient and low-cost biomass pre-treatment method to reduce pH to levels suitable for downstream processes, enabling the conversion of cyanobacterial biomass into hydrogen and organic acids using cyanobacteria's own fermentative pathways. Temperature, initial biomass concentration, and oxygen presence were found to affect yield and distribution of organic acids. Autofermentation of alkaline cyanobacterial biomass was found to be a viable approach to produce hydrogen and organic acids simultaneously, while enabling the successful conversion of biomass to biogas. Between 5.8 and 60% of the initial carbon was converted into organic acids, 8.7-25% was obtained as soluble protein, and 16-72% stayed in the biomass. Interestingly, we found that extensive dewatering is not needed to effectively process the alkaline cyanobacterial biomass. Using natural settling as the only harvesting and dewatering method resulted in a slurry with relatively low biomass concentration. Nevertheless, autofermentation of this slurry led to the maximum total organic acid yield (60% C mol/C mol biomass) and hydrogen yield (326.1 µmol/g AFDM). CONCLUSION Autofermentation is a simple, but highly effective pretreatment that can play a significant role within a cyanobacterial-based biorefinery platform by enabling the conversion of alkaline cyanobacterial biomass into organic acids, hydrogen, and methane via anaerobic digestion without the addition of energy or chemicals.
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Affiliation(s)
- Cigdem Demirkaya
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, Canada
| | | | - Taina Tervahauta
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, Canada
| | - Marc Strous
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
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Xie CJ, Yang S, Han S, Liu GH, Zhou SG. Shouchella tritolerans sp. nov., a facultative anaerobic bacterium isolated from marine sediments. Arch Microbiol 2023; 205:137. [PMID: 36961602 DOI: 10.1007/s00203-023-03474-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/22/2023] [Accepted: 03/07/2023] [Indexed: 03/25/2023]
Abstract
An alkali, salt, and thermo-tolerant strain designated FJAT-45399T was isolated from marine sediment in Fujian Province, China. Strain FJAT-45399T was Gram-stain-positive, rod-shaped, and facultatively aerobic. It shared high 16S rRNA gene sequence similarities with the members of the genus Shouchella. Further, the phylogenetic and phylogenomic analysis also suggested strain FJAT-45399T clustered with the members of the genus Shouchella. Growth of strain FJAT-45399T was observed at 15-55 °C (optimum 45-50 °C), pH 7.0-13.0 (optimum 9.0) and 0-15% (w/v) NaCl (optimum 2%). It contained MK-7 as the menaquinone. The polar lipids were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and an unidentified glycolipid (UGL) and lipid (UL). The major fatty acids (> 10%) were C16:0 (22.8%), iso-C15:0 (21.3%), and anteiso-C15:0 (14.0%). The genomic DNA G + C content was 44.5%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain FJAT-45399T and the most closely related type strain Shouchella clausii DSM 8716T (ANI 94.1% and dDDH 55.4%) were both below the cut-off level for species delineation. Based on the above results, strain FJAT-45399T represents a novel species of the genus Shouchella, for which the name Shouchella tritolerans sp. nov., is proposed. The type strain is FJAT-45399T (= GDMCC 1.3098T = JCM 35613T).
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Affiliation(s)
- Cheng-Jie Xie
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, People's Republic of China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, Guangdong, People's Republic of China
| | - Shang Yang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, People's Republic of China
| | - Shuang Han
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, People's Republic of China
| | - Guo-Hong Liu
- Agricultural Bio-Resources Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, People's Republic of China.
| | - Shun-Gui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, People's Republic of China.
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Naykodi A, Patankar SC, Thorat BN. Alkaliphiles for comprehensive utilization of red mud (bauxite residue)-an alkaline waste from the alumina refinery. Environ Sci Pollut Res Int 2023; 30:9350-9368. [PMID: 36480139 DOI: 10.1007/s11356-022-24190-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 11/09/2022] [Indexed: 06/17/2023]
Abstract
The mining industry has powered the human endeavor to make life more innovative, flexible, and comfortable. However, it has also led to concerns due to the increasing amount of mining and associated industrial waste. Special attention is highly desired for its proper management and safe disposal in the environment. The problem has only augmented with the increase in the mining costs because of the investments needed for ecological remediation after the mining operation. It is pertinent that the targeted technologies need to be developed to utilize mining and associated industrial waste as a secondary resource to ensure sustainable mining operations. Every perceived waste is a valuable resource that is needed to be utilized to create additional value. In this review, the case of alkaline bauxite residue (red mud)-alumina refinery waste has been discussed at length. The highlight of the proposed work is to understand the importance of alkaliphile-assisted biomining-a sustainable alternative to conventional metal recovery processes. Along with the recovery of metals, pH reduction of red mud is possible through biomining, which ultimately paves the way for its complete utilization. The unique adaptation strategies of alkaliphiles make them more suitable for biomining of red mud through bioleaching, biosorption, and bioaccumulation, which have been discussed here. Furthermore, we have focused on the potential of the indigenous microflora of red mud for metal recovery in addition to its neutralization. The study of indigenous alkaliphiles from red mud, including its isolation and propagation, is crucial for the industrial-scale application of alkaliphile-based technology and has been emphasized.
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Affiliation(s)
- Ankita Naykodi
- Department of Biotechnology, Institute of Chemical Technology-IndianOil Odisha Campus, Bhubaneswar, 751013, Odisha, India
| | - Saurabh C Patankar
- Department of Chemical Engineering, Institute of Chemical Technology-IndianOil Odisha Campus, Bhubaneswar, 751013, Odisha, India
| | - Bhaskar N Thorat
- Department of Chemical Engineering, Institute of Chemical Technology, Mumbai, 400019, India.
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Trutschel LR, Chadwick GL, Kruger B, Blank JG, Brazelton WJ, Dart ER, Rowe AR. Investigation of microbial metabolisms in an extremely high pH marine-like terrestrial serpentinizing system: Ney Springs. Sci Total Environ 2022; 836:155492. [PMID: 35476949 DOI: 10.1016/j.scitotenv.2022.155492] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/06/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
Ney Springs, a continental serpentinizing spring in northern California, has an exceptionally high reported pH (12.4) for a naturally occurring water source. With high conductivity fluids, it is geochemically more akin to marine serpentinizing systems than other terrestrial locations. Our geochemical analyses also revealed high sulfide concentrations (544 mg/L) and methane emissions (83% volume gas content) relative to other serpentinizing systems. Thermodynamic calculations were used to investigate the potential for substrates resulting from serpentinization to fuel microbial life, and were found to support the energetic feasibility of sulfate reduction, anaerobic methane oxidation, denitrification, and anaerobic sulfide oxidation within this system. Assessment of the microbial community via 16S rRNA taxonomic gene surveys and metagenome sequencing revealed a community composition dominated by poorly characterized members of the Izemoplasmatales and Clostridiales. The genomes of these dominant taxa point to a fermentative lifestyle, though other highly complete (>90%) metagenome assembled genomes support the potential for organisms to perform sulfate reduction, sulfur disproportionation and/or sulfur oxidation (aerobic and anaerobic). Two chemolithoheterotrophs identified in the metagenome, a Halomonas sp. and a Rhodobacteraceae sp., were isolated and shown to oxidize thiosulfate and were capable of growth in conditions up to pH 12.4. Despite being characteristic products of serpentinization reactions, little evidence was seen for hydrogen and methane utilization in the Ney Springs microbial community. Hydrogen is not highly abundant and could be consumed prior to reaching the spring community. Other metabolic strategies may be outcompeted by more energetically favorable heterotrophic or fermentation reactions, or even inhibited by other compounds in the spring such as ammonia. The unique geochemistry of Ney Springs provides an opportunity to study how local geology interacts with serpentinized fluids, while its microbial community can better inform us of the metabolic strategies employed in hyperalkaline environments.
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Affiliation(s)
- Leah R Trutschel
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Grayson L Chadwick
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | | | - Jennifer G Blank
- Blue Marble Space Institute of Science, Livermore, CA, USA; NASA Ames Research Center in Silicon Valley, Moffett Field, CA, USA
| | | | - Emily R Dart
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Annette R Rowe
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA.
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Liu Q, Yang M, Meng X, Han X, Nazare M, Xu Y, Hu HY, Zhang Q. Donor manipulation for constructing a pH sensing thermally activated delayed fluorescent probe to detect alkaliphiles. Talanta 2022; 246:123493. [PMID: 35489098 DOI: 10.1016/j.talanta.2022.123493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 04/13/2022] [Accepted: 04/17/2022] [Indexed: 11/30/2022]
Abstract
pH homeostasis is essential for alkaliphiles, given their widespread use in biotechnological applications. However, quantitative monitoring of alkaline pH in alkaliphiles remains challenging. Here, we synthesized for the first time, a thermally activated delayed fluorescent (TADF) pH probe: NI-D-OH. Our probe exhibits a good linear relationship between fluorescence intensity and pH in the neutral to alkaline range (pH 7.0-8.6), as well as long-lived TADF emission. We further show that NI-D-OH can be used to monitor intracellular pH in living organisms, and evaluate the effect of Na+ on the pH homeostasis, demonstrating the potential for alkaline pH monitoring and time-resolved fluorescence imaging.
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Affiliation(s)
- Qian Liu
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Beijing Key Laboratory of Active Substances Discovery and Drugability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
| | - Miao Yang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Beijing Key Laboratory of Active Substances Discovery and Drugability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China; School of Pharmaceutical Engineering and Key Laboratory of Structure-Based Drug Design & Discovery (Ministry of Education), Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Xiangchuan Meng
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Beijing Key Laboratory of Active Substances Discovery and Drugability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
| | - Xiaowan Han
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Beijing Key Laboratory of Active Substances Discovery and Drugability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
| | - Marc Nazare
- Medicinal Chemistry, Leibniz-Forschungsinstitut für Molekulare Pharmakologie Berlin, 13125, Berlin, Germany
| | - Youjun Xu
- School of Pharmaceutical Engineering and Key Laboratory of Structure-Based Drug Design & Discovery (Ministry of Education), Shenyang Pharmaceutical University, Shenyang, 110016, China.
| | - Hai-Yu Hu
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Beijing Key Laboratory of Active Substances Discovery and Drugability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China.
| | - Qingyang Zhang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Beijing Key Laboratory of Active Substances Discovery and Drugability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China.
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Silva B, Antunes C, Andrade F, Ferreira da Silva E, Grande JA, Luís AT. Prokaryotic and eukaryotic diversity in hydrothermal continental systems. Arch Microbiol 2021; 203:3751-66. [PMID: 34143270 DOI: 10.1007/s00203-021-02416-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 02/07/2023]
Abstract
The term extremophile was suggested more than 30 years ago and represents microorganisms that are capable of developing and living under extreme conditions, these conditions being particularly hostile to other types of microorganisms and to humankind. In terrestrial hydrothermal sites, like hot springs, "mud pools", solfataras, and geysers, the dominant extreme conditions are high temperature, low or high pH, and high levels of salinity. The diversity of microorganisms inhabiting these sites is determined by the conditions of the environment. Organisms belonging to the domains Archaea and Bacteria are more represented than the one belonging to Eukarya. Eukarya members tend to be less present because of their lower tolerance to higher temperatures, however, they perform important ecosystem processes when present. Both prokaryotes and eukaryotes have morphological and physical adaptations that allow them to colonize extreme environments. Microbial mats are complex associations of microorganisms that help the colonization of more extreme systems. In this review, a characterization of prokaryotic and eukaryotic organisms that populate terrestrial hydrothermal systems are made.
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de Jong SI, van den Broek MA, Merkel AY, de la Torre Cortes P, Kalamorz F, Cook GM, van Loosdrecht MCM, McMillan DGG. Genomic analysis of Caldalkalibacillus thermarum TA2.A1 reveals aerobic alkaliphilic metabolism and evolutionary hallmarks linking alkaliphilic bacteria and plant life. Extremophiles 2020; 24:923-935. [PMID: 33030592 PMCID: PMC7561548 DOI: 10.1007/s00792-020-01205-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 09/23/2020] [Indexed: 12/28/2022]
Abstract
The aerobic thermoalkaliphile Caldalkalibacillus thermarum strain TA2.A1 is a member of a separate order of alkaliphilic bacteria closely related to the Bacillales order. Efforts to relate the genomic information of this evolutionary ancient organism to environmental adaptation have been thwarted by the inability to construct a complete genome. The existing draft genome is highly fragmented due to repetitive regions, and gaps between and over repetitive regions were unbridgeable. To address this, Oxford Nanopore Technology's MinION allowed us to span these repeats through long reads, with over 6000-fold coverage. This resulted in a single 3.34 Mb circular chromosome. The profile of transporters and central metabolism gives insight into why the organism prefers glutamate over sucrose as carbon source. We propose that the deamination of glutamate allows alkalization of the immediate environment, an excellent example of how an extremophile modulates environmental conditions to suit its own requirements. Curiously, plant-like hallmark electron transfer enzymes and transporters are found throughout the genome, such as a cytochrome b6c1 complex and a CO2-concentrating transporter. In addition, multiple self-splicing group II intron-encoded proteins closely aligning to those of a telomerase reverse transcriptase in Arabidopsis thaliana were revealed. Collectively, these features suggest an evolutionary relationship to plant life.
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Affiliation(s)
- Samuel I de Jong
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Alexander Y Merkel
- Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | | | - Falk Kalamorz
- The New Zealand Institute for Plant and Food Research, Lincoln, New Zealand
| | - Gregory M Cook
- Department of Microbiology and Immunology, The University of Otago, Dunedin, New Zealand
| | | | - Duncan G G McMillan
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
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Pathak AP, Rathod MG, Mahabole MP, Khairnar RS. Enhanced catalytic activity of Bacillus aryabhattai P1 protease by modulation with nanoactivator. Heliyon 2020; 6:e04053. [PMID: 32529068 PMCID: PMC7276444 DOI: 10.1016/j.heliyon.2020.e04053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/26/2020] [Accepted: 05/19/2020] [Indexed: 11/24/2022] Open
Abstract
In the developing area of modern nanobiotechnology, the research is being focused on enhancement of catalytic performance in terms of efficiency and stability of enzymes to fulfill the industrial demand. In the context of this interdisciplinary era, we isolated and identified alkaline protease producer Bacillus aryabhattai P1 by polyphasic approach and then followed one variable at a time approach to optimize protease production from P1. The modified components of fermentation medium (g/L) were wheat bran 10, soybean flour 10, yeast extract 5, NaCl 10, KH2PO4 1, K2HPO4 1 and MgSO4·7H2O 0.2 (pH 9). The optimum alkaline protease production from P1 was recorded 75 ± 3 U/mg at 35 °C and pH 9 after 96 h of fermentation period. Molecular weight of partially purified P1 alkaline protease was 26 KDa as revealed by SDS-PAGE. Calcium based nanoceramic material was prepared by wet chemical precipitation method and doped in native P1 protease for catalytic activity enhancement. Catalytic activity of modified P1 protease was attained by nanoactivator mediated modulation was more by 5.58 fold at pH 10 and 30 °C temperature. The nanoceramic material named as nanoactivator, with grain size of 40–60 nm was suitable to redesign the active site of P1 protease. Such types of modified proteases can be used in different nanobiotechnological applications.
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Affiliation(s)
- Anupama P Pathak
- School of Life Sciences (DST-FIST Phase-I & UGC-SAP DRS-II Sponsored School), Swami Ramanand Teerth Marathwada University, Nanded 431606, Maharashtra, India
| | - Mukundraj G Rathod
- Department of Biotechnology & Bioinformatics (U.G. & P.G.), Yeshwant College of Information Technology (BT & BI) Parbhani (affiliated to S.R.T.M. University, Nanded), Maharashtra, India
| | - Megha P Mahabole
- School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606, Maharashtra, India
| | - Rajendra S Khairnar
- School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606, Maharashtra, India
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Odoch M, Buys EM, Taylor JRN. Solid-State Fermentation of Cassava Roots Using Cellulolytic-Type Alkaliphilic Bacillus spp. Cultures to Modify the Cell Walls and Assist Starch Release. Appl Biochem Biotechnol 2020; 191:1395-410. [PMID: 32103472 DOI: 10.1007/s12010-020-03286-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/13/2020] [Indexed: 10/24/2022]
Abstract
To improve cassava starch extraction by wet milling, solid-state fermentation of ground roots using cellulolytic-type alkaliphilic Bacilli spp., Bacillus akibai, B. cellulosilyticus and B. hemicellulosilyticus was investigated. Enzyme assay and scanning electron microscopy indicated that Bacillus spp. production of extracellular cellulase and polygalacturonase caused the formation of micropores through the root parenchyma cell walls and exposed the embedded cellulosic network. Gas chromatography data of the cell wall constituent sugars remaining after fermentation and Fourier transform infrared data indicated that the Bacillus treatments reduced the levels of pectin and, hemicellulose and to lesser extent cellulose. Wide-angle X-ray scattering data indicated that the Bacillus spp. cell wall degrading enzymes had partially hydrolysed the amorphous fractions of the cell wall polysaccharides. All the Bacillus spp. treatments improved starch extraction by 17-23% compared to fermentation with endogenous microflora. B. cellulosilyticus was most effective in disintegration of large root particles and as result, released marginally the most starch, probably due to it having the highest cellulase activity. Solid-state fermentation using cellulolytic-type Bacillus spp. is, therefore, promising to technology to improve the efficiency of cassava wet milling cell wall disintegration and consequent starch yield without use of commercial cell wall degrading enzymes or polluting chemicals.
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Liu GH, Narsing Rao MP, Dong ZY, Wang JP, Chen Z, Liu B, Li WJ. Two novel alkaliphiles, Bacillus alkalisoli sp. nov., and Bacillus solitudinis sp. nov., isolated from saline-alkali soil. Extremophiles 2019; 23:759-764. [PMID: 31538256 DOI: 10.1007/s00792-019-01127-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 08/27/2019] [Indexed: 02/06/2023]
Abstract
Two alkaliphilic strains, designated FJAT-45086T and FJAT-45122T, were isolated from alkali soli in Nima County, Tibet, China. Both strains were Gram-positive, rod-shaped and shared low 16S rRNA gene sequence similarity with the members of the genus Bacillus. They contained meso-diaminopimelic acid as the cell-wall diamino acid and MK-7 as the menaquinone. The major fatty acids (>5%) of strain FJAT-45086T were anteiso-C15:0, C16:0, iso-C15:0, C16:1ω11c and anteiso-C17:0, whereas strain FJAT-45122T consisted of iso-C15:0, anteiso-C15:0, iso-C17:1ω10c, iso-C17:0, anteiso-C17:0, C16:0 and C16:1ω11c. The genome G + C content of strains FJAT-45086T and FJAT-45122T was 37.8 and 38.2 mol%, respectively. The polar lipids of strain FJAT-45086T were diphosphatidyl glycerol (DPG), phosphatidyl glycerol (PG), phosphatidyl ethanolamine (PE), and phosphatidyl choline (PC), whereas strain FJAT-45122T consisted of DPG, PG, phosphatidyl methyl ethanolamine (PME) and an unidentified aminophospholipids (UAPL). The average nucleotide identity values of strains FJAT-45086T and FJAT-45122T were below the cut-off level (95-96%) for species delineation. Based on the results, strains FJAT-45086T and FJAT-45122T represent two novel species of the genus Bacillus, for which the names Bacillus alkalisoli sp. nov., and Bacillus solitudinis sp. nov., are proposed. The type strain, FJAT-45122T (=DSM 104631T = CCTCC AB 2016254T), FJAT-45086T (=DSM 104056T = CCTCC AB 2016232T).
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Affiliation(s)
- Guo-Hong Liu
- Agricultural Bio-Resources Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, People's Republic of China
| | - Manik Prabhu Narsing Rao
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Zhou-Yan Dong
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Jie-Ping Wang
- Agricultural Bio-Resources Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, People's Republic of China
| | | | - Bo Liu
- Agricultural Bio-Resources Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, People's Republic of China.
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
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Abstract
Continental hydrothermal systems are a dynamic component of global thermal and geochemical cycles, exerting a pronounced impact on water chemistry and heat storage. As such, these environments are commonly classified by temperature, thermal fluid ionic concentration, and pH. Terrestrial hydrothermal systems are a refuge for extremophilic organisms, as extremes in temperature, metal concentration, and pH profoundly impact microorganism assemblage composition. While numerous studies focus on Bacteria and Archaea in these environments, few focus on Eukarya-likely due to lower temperature tolerances and because they are not model organisms for understanding the evolution of early life. However, where present, eukaryotic organisms are significant members of continental hydrothermal microorganism communities. Thus, this manuscript focuses on the eukaryotic occupants of terrestrial hydrothermal systems and provides a review of the current status of research, including microbe-eukaryote interactions and suggestions for future directions.
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Affiliation(s)
- Sabrina R Brown
- Department of Earth and Atmospheric Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.
| | - Sherilyn C Fritz
- Department of Earth and Atmospheric Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.,School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
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14
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Abstract
Starch is a carbohydrate polymer found abundantly on earth. It is synthesized in plants as a short-term storage compound for respiration in the leaves and for long-term storage in the tubers, seeds and roots of plants. A wide variety of enzymes modify or convert starch into various products. The classes of enzymes that act on starch include endoamylases, exoamylases, debranching enzymes and transferases. Starch-modifying enzymes of microbial origin are utilized in a wide variety of industrial applications. Alkaline-active amylases are diverse in terms of optimum reaction conditions, substrate and product specificity. Amylases that are active at lower temperatures and alkaline conditions are most suited for detergent formulation. Other notable starch-modifying enzymes from alkaliphiles include maltooligosaccharide-forming amylases and cyclodextrin glycosyltransferases (CGTases), which produce a variety of maltooligosaccharides and cyclodextrins, respectively. Such compounds are used in the food, fine chemical, pharmaceutical and cosmetic industries, among others. Alkaline-active amylases are also applicable in the paper, textile and leather industries and also in bioremediation and alkaline waste water treatment. Their application in these fields is further enhanced through stabilization and improving their specificity and catalytic action by employing nanotechnology and genetic engineering. Graphical Abstract *Alkaline alpha-amylase AmyK from Bacillus sp. KSM-1378. Shirai T, Igarashi K, Ozawa T, Hagihara H, Kobayashi T, Ozaki K, Ito S (2007) Proteins 66:600-610. Source: Protein Data Bank in Europe (PDBe).
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Affiliation(s)
- Suhaila Omar Hashim
- Department of Biochemistry and Biotechnology, Pwani University, Kilifi, Kenya.
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15
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Abstract
Alkalinicity presents a challenge for life due to a "reversed" proton gradient that is unfavourable to many bioenergetic processes across the membranes of microorganisms. Despite this, many bacteria, archaea, and eukaryotes, collectively termed alkaliphiles, are adapted to life in alkaline ecosystems and are of great scientific and biotechnological interest due to their niche specialization and ability to produce highly stable enzymes. Advances in next-generation sequencing technologies have propelled not only the genomic characterization of many alkaliphilic microorganisms that have been isolated from nature alkaline sources but also our understanding of the functional relationships between different taxa in microbial communities living in these ecosystems. In this review, we discuss the genetics and molecular biology of alkaliphiles from an "omics" point of view, focusing on how metagenomics and transcriptomics have contributed to our understanding of these extremophiles. Graphical Abstract.
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Affiliation(s)
- Pedro H Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.
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16
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Abstract
Concrete is one of the most commonly used building materials ever used. Despite it is a very important and common construction material, concrete is very sensitive to crack formation and requires repair. A variety of chemical-based techniques and materials have been developed to repair concrete cracks. Although the use of these chemical-based repair systems are the best commercially available choices, there have also been concerns related to their use. These repair agents suffer from inefficiency and unsustainability. Most of the products are expensive and susceptible to degradation, exhibit poor bonding to the cracked concrete surfaces, and are characterized by different physical properties such as thermal expansion coefficients which are different to that of concrete. Moreover, many of these repair agents contain chemicals that pose environmental and health hazards. Thus, there has been interest in developing concrete crack repair agents that are efficient, long lasting, safe, and benign to the environment and exhibit physical properties which resemble that of the concrete. The search initiated by these desires brought the use of biomineralization processes as tools in mending concrete cracks. Among biomineralization processes, microbially initiated calcite precipitation has emerged as an interesting alternative to the existing chemical-based concrete crack repairing system. Indeed, results of several studies on the use of microbial-based concrete repair agents revealed the remarkable potential of this approach in the fight against concrete deterioration. In addition to repairing existing concrete cracks, microorganisms have also been considered to make protective surface coating (biodeposition) on concrete structures and in making self-healing concrete.Even though a wide variety of microorganisms can precipitate calcite, the nature of concrete determines their applicability. One of the important factors that determine the applicability of microbes in concrete is pH. Concrete is highly alkaline in nature, and hence the microbes envisioned for this application are alkaliphilic or alkali-tolerant. This work reviews the available information on applications of microbes in concrete: repairing existing cracks, biodeposition, and self-healing. Moreover, an effort is made to discuss biomineralization processes that are relevant to extend the durability of concrete structures. Graphical Abstract.
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Del Arco J, Cejudo-Sanches J, Esteban I, Clemente-Suárez VJ, Hormigo D, Perona A, Fernández-Lucas J. Enzymatic production of dietary nucleotides from low-soluble purine bases by an efficient, thermostable and alkali-tolerant biocatalyst. Food Chem 2017; 237:605-611. [PMID: 28764042 DOI: 10.1016/j.foodchem.2017.05.136] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 05/16/2017] [Accepted: 05/28/2017] [Indexed: 11/17/2022]
Abstract
Traditionally, enzymatic synthesis of nucleoside-5'-monophosphates (5'-NMPs) using low water-soluble purine bases has been described as less efficient due to their low solubility in aqueous media. The use of enzymes from extremophiles, such as thermophiles or alkaliphiles, offers the potential to increase solubilisation of these bases by employing high temperatures or alkaline pH. This study describes the cloning, expression and purification of hypoxanthine-guanine-xanthine phosphoribosyltransferase from Thermus thermophilus (TtHGXPRT). Biochemical characterization indicates TtHGXPRT as a homotetramer with excellent activity and stability across a broad range of temperatures (50-90°C) and ionic strengths (0-500mMNaCl), but it also reveals an unusually high activity and stability under alkaline conditions (pH range 8-11). In order to explore the potential of TtHGXPRT as an industrial biocatalyst, enzymatic production of several dietary 5'-NMPs, such as 5'-GMP and 5'-IMP, was carried out at high concentrations of guanine and hypoxanthine.
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Affiliation(s)
- J Del Arco
- Applied Biotechnology Group, Universidad Europea de Madrid, Urbanización El Bosque, Calle Tajo, s/n, 28670 Villaviciosa de Odón, Madrid, Spain
| | - J Cejudo-Sanches
- Applied Biotechnology Group, Universidad Europea de Madrid, Urbanización El Bosque, Calle Tajo, s/n, 28670 Villaviciosa de Odón, Madrid, Spain
| | - I Esteban
- Applied Biotechnology Group, Universidad Europea de Madrid, Urbanización El Bosque, Calle Tajo, s/n, 28670 Villaviciosa de Odón, Madrid, Spain
| | - V J Clemente-Suárez
- Applied Biotechnology Group, Universidad Europea de Madrid, Urbanización El Bosque, Calle Tajo, s/n, 28670 Villaviciosa de Odón, Madrid, Spain
| | - D Hormigo
- Applied Biotechnology Group, Universidad Europea de Madrid, Urbanización El Bosque, Calle Tajo, s/n, 28670 Villaviciosa de Odón, Madrid, Spain
| | - A Perona
- Applied Biotechnology Group, Universidad Europea de Madrid, Urbanización El Bosque, Calle Tajo, s/n, 28670 Villaviciosa de Odón, Madrid, Spain
| | - J Fernández-Lucas
- Applied Biotechnology Group, Universidad Europea de Madrid, Urbanización El Bosque, Calle Tajo, s/n, 28670 Villaviciosa de Odón, Madrid, Spain; Grupo de Investigación en Desarrollo Agroindustrial Sostenible, Universidad de la Costa, CUC, Calle 58 # 55-66, Barranquilla, Colombia.
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18
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Takahashi Y, Ito M. Ion Selectivity of the Flagellar Motors Derived from the Alkaliphilic Bacillus and Paenibacillus Species. Methods Mol Biol 2017; 1593:297-303. [PMID: 28389964 DOI: 10.1007/978-1-4939-6927-2_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Many bacteria can swim using their flagella, which are filamentous organelles that extend from the cell surface. The flagellar motor is energized by either a proton (H+) or sodium ion (Na+) as the motive force. MotAB-type stators use protons, whereas MotPS- and PomAB-type stators use Na+ as the coupling ions. Recently, alkaliphilic Bacillus alcalophilus was shown to use potassium ions (K+) and rubidium ions (Rb+) for flagellar rotation, and the flagellar motor from Paenibacillus sp. TCA-20 uses divalent cations such as magnesium ions (Mg2+), calcium ions (Ca2+), and strontium ions (Sr2+) for coupling. In this chapter, we focus on how to identify the coupling ions for flagellar rotation of alkaliphilic Bacillus and Paenibacillus species.
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Kalwasińska A, Felföldi T, Szabó A, Deja-Sikora E, Kosobucki P, Walczak M. Microbial communities associated with the anthropogenic, highly alkaline environment of a saline soda lime, Poland. Antonie Van Leeuwenhoek 2017; 110:945-962. [PMID: 28382378 PMCID: PMC5486852 DOI: 10.1007/s10482-017-0866-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 03/28/2017] [Indexed: 11/30/2022]
Abstract
Soda lime is a by-product of the Solvay soda process for the production of sodium carbonate from limestone and sodium chloride. Due to a high salt concentration and alkaline pH, the lime is considered as a potential habitat of haloalkaliphilic and haloalkalitolerant microbial communities. This artificial and unique environment is nutrient-poor and devoid of vegetation, due in part to semi-arid, saline and alkaline conditions. Samples taken from the surface layer of the lime and from the depth of 2 m (both having pH ~11 and ECe up to 423 dS m−1) were investigated using culture-based (culturing on alkaline medium) and culture-independent microbiological approaches (microscopic analyses and pyrosequencing). A surprisingly diverse bacterial community was discovered in this highly saline, alkaline and nutrient-poor environment, with the bacterial phyla Proteobacteria (representing 52.8% of the total bacterial community) and Firmicutes (16.6%) showing dominance. Compared to the surface layer, higher bacterial abundance and diversity values were detected in the deep zone, where more stable environmental conditions may occur. The surface layer was dominated by members of the genera Phenylobacterium, Chelativorans and Skermanella, while in the interior layer the genus Fictibacillus was dominant. The culturable aerobic, haloalkaliphilic bacteria strains isolated in this study belonged mostly to the genus Bacillus and were closely related to the species Bacillus pseudofirmus, B. cereus, B. plakortidis, B. thuringensis and B. pumilus.
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Affiliation(s)
- Agnieszka Kalwasińska
- Department of Environmental Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Toruń, Poland.
| | - Tamás Felföldi
- Department of Microbiology, Eötvös Loránd University, Budapest, Hungary
| | - Attila Szabó
- Department of Microbiology, Eötvös Loránd University, Budapest, Hungary
| | - Edyta Deja-Sikora
- Department of Environmental Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Toruń, Poland
| | - Przemysław Kosobucki
- Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Toruń, Poland
| | - Maciej Walczak
- Department of Environmental Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Toruń, Poland
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20
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Sreenivasulu B, Paramageetham C, Sreenivasulu D, Suman B, Umamahesh K, Babu GP. Analysis of Chemical Signatures of Alkaliphiles using Fatty Acid Methyl Ester Analysis. J Pharm Bioallied Sci 2017; 9:106-114. [PMID: 28717333 PMCID: PMC5508411 DOI: 10.4103/jpbs.jpbs_286_16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Fatty acids occur in nearly all living organisms as the important predominant constituents of lipids. While all fatty acids have essentially the same chemical nature, they are an extremely diverse group of compounds. MATERIALS AND METHODS To test the hypothesis, fatty acids of alkaliphiles isolates, Bacillus subtilis SVUNM4, Bacillus licheniformis SVUNM8, Bacillus methylotrohicus SVUNM9, and Paenibacillus dendritiformis SVUNM11, were characterized compared using gas chromatography-mass spectrometry (GC-MS) analysis. RESULTS The content of investigated ten fatty acids, 1, 2-benzenedicarboxylic acid butyl 2-methylpropyl ester, phthalic acid, isobutyl 2-pentyl ester, dibutyl phthalate, cyclotrisiloxane, hexamethyl, cyclotetrasiloxane, octamethyl, dodecamethyl, heptasiloxane 1,1,3,3,5,5,7,7,9,9,11,11,13,13-etradecamethyl, 7,15-dihydroxydehydroabietic acid, methyl ester, di (trimethylsilyl) ether, hentriacontane, 2-thiopheneacetic acid, undec-2-enyl ester, obviously varied among four species, suggesting each species has its own fatty acid pattern. CONCLUSIONS These findings demonstrated that GC-MS-based fatty acid profiling analysis provides the reliable platform to classify these four species, which is helpful for ensuring their biotechnological interest and novel chemotaxonomic.
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Affiliation(s)
- Basha Sreenivasulu
- Department of Microbiology, Sri Venkateswara University, Tirupati, Andhra Pradesh, India
| | | | - Dasari Sreenivasulu
- Department of Biochemistry, Sri Venkateswara University, Tirupati, Andhra Pradesh, India
| | - Bukke Suman
- Department of Biochemistry, Sri Venkateswara University, Tirupati, Andhra Pradesh, India
| | - Katike Umamahesh
- Department of Biochemistry, Sri Venkateswara University, Tirupati, Andhra Pradesh, India
| | - Gundala Prasada Babu
- Department of Microbiology, Sri Venkateswara University, Tirupati, Andhra Pradesh, India
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21
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Ito M, Takahashi Y. Nonconventional cation-coupled flagellar motors derived from the alkaliphilic Bacillus and Paenibacillus species. Extremophiles 2016; 21:3-14. [PMID: 27771767 DOI: 10.1007/s00792-016-0886-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/10/2016] [Indexed: 12/21/2022]
Abstract
Prior to 2008, all previously studied conventional bacterial flagellar motors appeared to utilize either H+ or Na+ as coupling ions. Membrane-embedded stator complexes support conversion of energy using transmembrane electrochemical ion gradients. The main H+-coupled stators, known as MotAB, differ from Na+-coupled stators, PomAB of marine bacteria, and MotPS of alkaliphilic Bacillus. However, in 2008, a MotAB-type flagellar motor of alkaliphilic Bacillus clausii KSM-K16 was revealed as an exception with the first dual-function motor. This bacterium was identified as the first bacterium with a single stator-rotor that can utilize both H+ and Na+ for ion-coupling at different pH ranges. Subsequently, another exception, a MotPS-type flagellar motor of alkaliphilic Bacillus alcalophilus AV1934, was reported to utilize Na+ plus K+ and Rb+ as coupling ions for flagellar rotation. In addition, the alkaline-tolerant bacterium Paenibacillus sp. TCA20, which can utilize divalent cations such as Ca2+, Mg2+, and Sr2+, was recently isolated from a hot spring in Japan, which contains a high Ca2+ concentration. These findings show that bacterial flagellar motors isolated from unique environments utilize unexpected coupling ions. This suggests that bacteria that grow in different extreme environments adapt to local conditions and evolve their motility machinery.
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Affiliation(s)
- Masahiro Ito
- Faculty of Life Sciences, Toyo University, Oura-gun, Gunma, 374-0193, Japan. .,Bio-nano Electronics Research Center, Toyo University, Kawagoe, Saitama, 350-8585, Japan.
| | - Yuka Takahashi
- Bio-nano Electronics Research Center, Toyo University, Kawagoe, Saitama, 350-8585, Japan
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22
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Morino M, Ogoda S, Krulwich TA, Ito M. Differences in the phenotypic effects of mutations in homologous MrpA and MrpD subunits of the multi-subunit Mrp-type Na +/H + antiporter. Extremophiles 2016; 21:51-64. [PMID: 27709304 DOI: 10.1007/s00792-016-0877-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 09/24/2016] [Indexed: 10/20/2022]
Abstract
Mrp antiporters are the sole antiporters in the Cation/Proton Antiporter 3 family of transporter databases because of their unusual structural complexity, 6-7 hydrophobic proteins that function as a hetero-oligomeric complex. The two largest and homologous subunits, MrpA and MrpD, are essential for antiport activity and have direct roles in ion transport. They also show striking homology with proton-conducting, membrane-embedded Nuo subunits of respiratory chain complex I of bacteria, e.g., Escherichia coli. MrpA has the closest homology to the complex I NuoL subunit and MrpD has the closest homology to the complex I NuoM and N subunits. Here, introduction of mutations in MrpD, in residues that are also present in MrpA, led to defects in antiport function and/or complex formation. No significant phenotypes were detected in strains with mutations in corresponding residues of MrpA, but site-directed changes in the C-terminal region of MrpA had profound effects, showing that the MrpA C-terminal region has indispensable roles in antiport function. The results are consistent with a divergence in adaptations that support the roles of MrpA and MrpD in secondary antiport, as compared to later adaptations supporting homologs in primary proton pumping by the respiratory chain complex I.
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Affiliation(s)
- Masato Morino
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,, 573-13 Kamitanui, Tarnaki-cho, Watarai-gun, Mie, 519-0417, Japan
| | - Shinichiro Ogoda
- Faculty of Life Sciences, Graduate School of Life Sciences, Toyo University, Oura-gun, Gunma, 374-0193, Japan
| | - Terry Ann Krulwich
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Masahiro Ito
- Faculty of Life Sciences, Graduate School of Life Sciences, Toyo University, Oura-gun, Gunma, 374-0193, Japan. .,Bio-Nano Electronics Research Center, Toyo University, Kawagoe, Saitama, 350-0815, Japan.
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23
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Ramanathan T, Ting YP. Alkaline bioleaching of municipal solid waste incineration fly ash by autochthonous extremophiles. Chemosphere 2016; 160:54-61. [PMID: 27362528 DOI: 10.1016/j.chemosphere.2016.06.055] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 05/31/2016] [Accepted: 06/12/2016] [Indexed: 06/06/2023]
Abstract
The increasing demand for energy and the generation of solid waste have caused an alarming rise in fly ash production globally. Since heavy metals continue to be in demand for the production of materials, resource recovery from the recycling of these wastes has the potential to delay the depletion of natural ores. The use of microorganisms for the leaching of metals, in a process called bioleaching, is an eco-friendly and economical way to treat the metal-laden wastes. Bioleaching of fly ash is challenging due largely to the alkaline nature and toxic levels of heavy metals which are detrimental to microbial growth and bioleaching activity. The present work reports the isolation of indigenous bacteria from a local landfill site and their bioleaching performance [corrected]. 38 autochthonous strains of bacteria were isolated from eight samples collected and plated on five different media. 18 of the isolates showed bioleaching potential, with significant alkaline pH or fly ash tolerance. Genetic characterization of the strains revealed a dominance of Firmicutes, with Alkalibacterium sp. TRTYP6 showing highest fly ash tolerance of up to 20% w/v fly ash, and growth over a pH range 8-12.5. The organism selectively recovered about 52% Cu from the waste. To the best of our knowledge, this is the first time a study on bioleaching with extreme alkaliphiles is reported.
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Affiliation(s)
- Thulasya Ramanathan
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore
| | - Yen-Peng Ting
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore.
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24
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Kunal, Rajor A, Siddique R. Bacterial treatment of alkaline cement kiln dust using Bacillus halodurans strain KG1. Braz J Microbiol 2016; 47:1-9. [PMID: 26887220 DOI: 10.1016/j.bjm.2015.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 07/06/2015] [Indexed: 11/29/2022] Open
Abstract
This study was conducted to isolate an acid-producing, alkaliphilic bacterium to reduce the alkalinity of cement industry waste (cement kiln dust). Gram-positive isolate KG1 grew well at pH values of 6–12, temperatures of 28–50 °C, and NaCl concentrations of 0–16% and thus was further screened for its potential to reduce the pH of an alkaline medium. Phenotypic characteristics of the KG1 isolate were consistent with those of the genus Bacillus, and the highest level of 16S rRNA gene sequence similarity was found with Bacillus halodurans strain DSM 497 (94.7%). On the basis of its phenotypic characteristics and genotypic distinctiveness from other phylogenetic neighbors belonging to alkaliphilic Bacillus species, the isolated strain was designated B. halodurans strain KG1, with GenBank accession number JQ307184 (= NCIM 5439). Isolate KG1 reduced the alkalinity (by 83.64%) and the chloride content (by 86.96%) of cement kiln dust and showed a potential to be used in the cement industry for a variety of applications.
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25
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Dhakar K, Pandey A. Wide pH range tolerance in extremophiles: towards understanding an important phenomenon for future biotechnology. Appl Microbiol Biotechnol 2016; 100:2499-510. [PMID: 26780356 DOI: 10.1007/s00253-016-7285-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/28/2015] [Accepted: 12/29/2015] [Indexed: 12/20/2022]
Abstract
Microorganisms that inhabit the extreme pH environments are classified as acidophiles and alkaliphiles. A number of studies emerged from extreme high (hot springs, hydrothermal vents) as well as low temperature (arctic and antarctic regions, sea water, ice shelf, marine sediments, cold deserts, glaciers, temperate forests, and plantations) environments have highlighted the occurrence of microorganisms (thermophiles/psychrophiles) with the ability to tolerate wide pH range, from acidic to alkaline (1.5-14.0 in some cases), under laboratory conditions. However, the sampling source (soil/sediment) of these microorganisms showed the pH to be neutral or slightly acidic/alkaline. The aim of the present review is to discuss the phenomenon of wide pH range tolerance possessed by these microorganisms as a hidden character in perspective of their habitats, possible mechanisms, phylogeny, ecological and biotechnological relevance, and future perspectives. It is believed that the genome is a probable reservoir of the hidden variations. The extremophiles have the ability to adapt against the environmental change that is probably through the expression/regulation of the specific genes that were already present in the genome. The phenomenon is likely to have broad implications in biotechnology, including both environmental (such as bioremediation, biodegradation, and biocontrol), and industrial applications (as a source of novel extremozymes and many other useful bioactive compounds with wide pH range tolerance).
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Affiliation(s)
- Kusum Dhakar
- Biotechnological Applications, G. B. Pant Institute of Himalayan Environment and Development, Kosi-Katarmal, Almora, 263 643, Uttarakhand, India
| | - Anita Pandey
- Biotechnological Applications, G. B. Pant Institute of Himalayan Environment and Development, Kosi-Katarmal, Almora, 263 643, Uttarakhand, India.
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