1
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Qiu Q, Li H, Sun X, Tian K, Gu J, Zhang F, Zhou D, Zhang X, Huo H. Integrating genomics, molecular docking, and protein expression to explore new perspectives on polystyrene biodegradation. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:135031. [PMID: 38943889 DOI: 10.1016/j.jhazmat.2024.135031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 06/01/2024] [Accepted: 06/23/2024] [Indexed: 07/01/2024]
Abstract
Faced with the escalating challenge of global plastic pollution, this study specifically addresses the research gap in the biodegradation of polystyrene (PS). A PS-degrading bacterial strain was isolated from the gut of Tenebrio molitor, and genomics, molecular docking, and proteomics were employed to thoroughly investigate the biodegradation mechanisms of Pseudomonas putida H-01 against PS. Using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (ATR-FTIR), and contact angle analysis, significant morphological and structural changes in the PS films under the influence of the H-01 strain were observed. The study revealed several potential degradation genes and ten enzymes that were specifically upregulated in the PS degradation environment. Additionally, a novel protein with laccase-like activity, LacQ1, was purified from this strain for the first time, and its crucial role in the PS degradation process was confirmed. Through molecular docking and molecular dynamics (MD) simulations, the interactions between the enzymes and PS were detailed, elucidating the binding and catalytic mechanisms of the degradative enzymes with the substrate. These findings have deepened our understanding of PS degradation.
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Affiliation(s)
- Qing Qiu
- School of Environment, Northeast Normal University, No. 2555 Jingyue Avenue, Changchun City, Jilin Province, China
| | - Han Li
- School of Environment, Northeast Normal University, No. 2555 Jingyue Avenue, Changchun City, Jilin Province, China
| | - Xuejian Sun
- School of Environment, Northeast Normal University, No. 2555 Jingyue Avenue, Changchun City, Jilin Province, China
| | - Kejian Tian
- School of Environment, Northeast Normal University, No. 2555 Jingyue Avenue, Changchun City, Jilin Province, China
| | - Jinming Gu
- School of Environment, Northeast Normal University, No. 2555 Jingyue Avenue, Changchun City, Jilin Province, China
| | - Fenglin Zhang
- School of Environment, Northeast Normal University, No. 2555 Jingyue Avenue, Changchun City, Jilin Province, China
| | - Dandan Zhou
- School of Environment, Northeast Normal University, No. 2555 Jingyue Avenue, Changchun City, Jilin Province, China; Engineering Research Center of Low-Carbon Treatment and Green Development of Polluted Water in Northeast China, Ministry of Education, Northeast Normal University, Changchun 130117, China
| | - Xinwen Zhang
- College of Pharmacy, Hainan Vocational University of Science and Technology, Haikou 571126, China.
| | - Hongliang Huo
- School of Environment, Northeast Normal University, No. 2555 Jingyue Avenue, Changchun City, Jilin Province, China; Engineering Research Center of Low-Carbon Treatment and Green Development of Polluted Water in Northeast China, Ministry of Education, Northeast Normal University, Changchun 130117, China.
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2
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Nithimethachoke T, Boonmak C, Morikawa M. A novel alkane monooxygenase evolved from a broken piece of ribonucleotide reductase in Geobacillus kaustophilus HTA426 isolated from Mariana Trench. Extremophiles 2024; 28:18. [PMID: 38353731 PMCID: PMC10867098 DOI: 10.1007/s00792-024-01332-8] [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: 11/04/2023] [Accepted: 12/30/2023] [Indexed: 02/16/2024]
Abstract
We have accidentally found that a thermophilic Geobacillus kaustophilus HTA426 is capable of degrading alkanes although it has no alkane oxygenating enzyme genes. Our experimental results revealed that a putative ribonucleotide reductase small subunit GkR2loxI (GK2771) gene encodes a novel heterodinuclear Mn-Fe alkane monooxygenase/hydroxylase. GkR2loxI protein can perform two-electron oxidations similar to homonuclear diiron bacterial multicomponent soluble methane monooxygenases. This finding not only answers a long-standing question about the substrate of the R2lox protein clade, but also expands our understanding of the vast diversity and new evolutionary lineage of the bacterial alkane monooxygenase/hydroxylase family.
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Affiliation(s)
- Tanasap Nithimethachoke
- Graduate School of Environmental Science, Hokkaido University, Kita-10 Nishi-5, Kita-ku, Sapporo, 060-0810, Japan
| | - Chanita Boonmak
- Department of Microbiology, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan Rd., Lat Yao, Chatuchak, Bangkok, 10900, Thailand
| | - Masaaki Morikawa
- Graduate School of Environmental Science, Hokkaido University, Kita-10 Nishi-5, Kita-ku, Sapporo, 060-0810, Japan.
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3
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Wang S, Yun Y, Tian X, Su Z, Liao Z, Li G, Ma T. HMDB: A curated database of genes involved in hydrocarbon monooxygenation reaction with homologous genes as background. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132397. [PMID: 37639797 DOI: 10.1016/j.jhazmat.2023.132397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/10/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023]
Abstract
The investigation of hydrocarbon degradation potential of environmental microorganisms is an important research topic, whether for the global carbon cycle or oil pollution remediation. Under aerobic conditions, the microorganisms employ a range of monooxygenases to use hydrocarbons substrates as a source of carbon and energy. With the explosion of sequencing data, mining genes in genomes or metagenomes has become computationally expensive and time-consuming. We proposed the HMDB, which is a professional gene database of hydrocarbon monooxygenases. HMDB contains 38 genes, which encode 11 monooxygenases responsible for the hydroxylation of 8 hydrocarbons. To reduce false positives, the strategy of using homologous genes as background noise was applied for HMDB. We added 10,095 gene sequences of homologous enzymes which took non-hydrocarbons as substrates to HMDB. The classic BLAST method and best-hit strategy were recommended for HMDB usage, but not limited. The performance of HMDB was validated using 264,402 prokaryote genomes from RefSeq and 51 metagenomes from SRA. The results showed that HMDB database had high sensitivity and low false positive rate. We release the HMDB database here, hoping to speed up the process for investigation of hydrocarbon monooxygenases in massive metagenomic data. HMDB is freely available at http://www.orgene.net/HMDB/.
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Affiliation(s)
- Shaojing Wang
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yuan Yun
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xuefeng Tian
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Zhaoying Su
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Zitong Liao
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Guoqiang Li
- College of Life Sciences, Nankai University, Tianjin 300071, China.
| | - Ting Ma
- College of Life Sciences, Nankai University, Tianjin 300071, China.
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4
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Ru J, Xue J, Sun J, Cova L, Deng L. Unveiling the hidden role of aquatic viruses in hydrocarbon pollution bioremediation. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132299. [PMID: 37597386 DOI: 10.1016/j.jhazmat.2023.132299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/28/2023] [Accepted: 08/12/2023] [Indexed: 08/21/2023]
Abstract
Hydrocarbon pollution poses substantial environmental risks to water and soil. Bioremediation, which utilizes microorganisms to manage pollutants, offers a cost-effective solution. However, the role of viruses, particularly bacteriophages (phages), in bioremediation remains unexplored. This study examines the diversity and activity of hydrocarbon-degradation genes encoded by environmental viruses, focusing on phages, within public databases. We identified 57 high-quality phage-encoded auxiliary metabolic genes (AMGs) related to hydrocarbon degradation, which we refer to as virus-encoded hydrocarbon degradation genes (vHYDEGs). These genes are encoded by taxonomically diverse aquatic phages and highlight the under-characterized global virosphere. Six protein families involved in the initial alkane hydroxylation steps were identified. Phylogenetic analyses revealed the diverse evolutionary trajectories of vHYDEGs across habitats, revealing previously unknown biodegraders linked evolutionarily with vHYDEGs. Our findings suggest phage AMGs may contribute to alkane and aromatic hydrocarbon degradation, participating in the initial, rate-limiting hydroxylation steps, thereby aiding hydrocarbon pollution bioremediation and promoting their propagation. To support future research, we developed vHyDeg, a database containing identified vHYDEGs with comprehensive annotations, facilitating the screening of hydrocarbon degradation AMGs and encouraging their bioremediation applications.
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Affiliation(s)
- Jinlong Ru
- Institute of Virology, Helmholtz Centre Munich - German Research Centre for Environmental Health, Neuherberg 85764, Germany; Chair of Prevention for Microbial Infectious Disease, Central Institute of Disease Prevention and School of Life Sciences, Technical University of Munich, Freising 85354, Germany
| | - Jinling Xue
- Institute of Virology, Helmholtz Centre Munich - German Research Centre for Environmental Health, Neuherberg 85764, Germany; Chair of Prevention for Microbial Infectious Disease, Central Institute of Disease Prevention and School of Life Sciences, Technical University of Munich, Freising 85354, Germany
| | - Jianfeng Sun
- Botnar Research Centre, University of Oxford, Oxford OX3 7LD, UK
| | - Linda Cova
- Institute of Virology, Helmholtz Centre Munich - German Research Centre for Environmental Health, Neuherberg 85764, Germany
| | - Li Deng
- Institute of Virology, Helmholtz Centre Munich - German Research Centre for Environmental Health, Neuherberg 85764, Germany; Chair of Prevention for Microbial Infectious Disease, Central Institute of Disease Prevention and School of Life Sciences, Technical University of Munich, Freising 85354, Germany.
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5
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Xiang W, Hong S, Xue Y, Ma Y. Functional Analysis of Novel alkB Genes Encoding Long-Chain n-Alkane Hydroxylases in Rhodococcus sp. Strain CH91. Microorganisms 2023; 11:1537. [PMID: 37375039 DOI: 10.3390/microorganisms11061537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Rhodococcus sp. strain CH91 is capable of utilizing long-chain n-alkanes as the sole carbon source. Two new genes (alkB1 and alkB2) encoding AlkB-type alkane hydroxylase were predicted by its whole-genome sequence analysis. The purpose of this study was to elucidate the functional role of alkB1 and alkB2 genes in the n-alkane degradation of strain CH91. RT-qPCR analyses revealed that the two genes were induced by n-alkanes ranging from C16 to C36 and the expression of the alkB2 gene was up-regulated much higher than that of alkB1. The knockout of the alkB1 or alkB2 gene in strain CH91 resulted in the obvious reduction of growth and degradation rates on C16-C36 n-alkanes and the alkB2 knockout mutant exhibited lower growth and degradation rate than the alkB1 knockout mutant. When gene alkB1 or alkB2 was heterologously expressed in Pseudomonas fluorescens KOB2Δ1, the two genes could restore its alkane degradation activity. These results demonstrated that both alkB1 and alkB2 genes were responsible for C16-C36 n-alkanes' degradation of strain CH91, and alkB2 plays a more important role than alkB1. The functional characteristics of the two alkB genes in the degradation of a broad range of n-alkanes make them potential gene candidates for engineering the bacteria used for bioremediation of petroleum hydrocarbon contaminations.
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Affiliation(s)
- Wei Xiang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shan Hong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanfen Xue
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanhe Ma
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
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Perera M, Wijesundera S, Wijayarathna CD, Seneviratne G, Jayasena S. Identification of long-chain alkane-degrading (LadA) monooxygenases in Aspergillus flavus via in silico analysis. Front Microbiol 2022; 13:898456. [PMID: 36110294 PMCID: PMC9468676 DOI: 10.3389/fmicb.2022.898456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 07/20/2022] [Indexed: 11/25/2022] Open
Abstract
Efficient degradation of alkanes in crude oil by the isolated Aspergillus flavus MM1 alluded to the presence of highly active alkane-degrading enzymes in this fungus. A long-chain alkane-degrading, LadA-like enzyme family in A. flavus was identified, and possible substrate-binding modes were analyzed using a computational approach. By analyzing publicly available protein databases, we identified six uncharacterized proteins in A. flavus NRRL 3357, of which five were identified as class LadAα and one as class LadAβ, which are eukaryotic homologs of bacterial long-chain alkane monooxygenase (LadA). Computational models of A. flavus LadAα homologs (Af1-Af5) showed overall structural similarity to the bacterial LadA and the unique sequence and structural elements that bind the cofactor Flavin mononucleotide (FMN). A receptor-cofactor-substrate docking protocol was established and validated to demonstrate the substrate binding in the A. flavus LadAα homologs. The modeled Af1, Af3, Af4, and Af5 captured long-chain n-alkanes inside the active pocket, above the bound FMN. Isoalloxazine ring of reduced FMN formed a π–alkyl interaction with the terminal carbon atom of captured alkanes, C16–C30, in Af3–Af5 and C16–C24 in Af1. Our results confirmed the ability of identified A. flavus LadAα monooxygenases to bind long-chain alkanes inside the active pocket. Hence A. flavus LadAα monooxygenases potentially initiate the degradation of long-chain alkanes by oxidizing bound long-chain alkanes into their corresponding alcohol.
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Affiliation(s)
- Madushika Perera
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - Sulochana Wijesundera
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | | | | | - Sharmila Jayasena
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
- *Correspondence: Sharmila Jayasena,
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7
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Tourova TP, Sokolova DS, Semenova EM, Ershov AP, Grouzdev DS, Nazina TN. Genomic and Physiological Characterization of Halophilic Bacteria of the Genera Halomonas and Marinobacter from Petroleum Reservoirs. Microbiology (Reading) 2022. [DOI: 10.1134/s0026261722300038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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8
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Microbial Consortiums of Putative Degraders of Low-Density Polyethylene-Associated Compounds in the Ocean. mSystems 2022; 7:e0141521. [PMID: 35229650 PMCID: PMC8941889 DOI: 10.1128/msystems.01415-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polyethylene (PE) is one of the most abundant plastics in the ocean. The development of a biofilm on PE in the ocean has been reported, yet whether some of the biofilm-forming organisms can biodegrade this plastic in the environment remains unknown. Via metagenomics analysis, we taxonomically and functionally analyzed three biofilm communities using low-density polyethylene (LDPE) as their sole carbon source for 2 years. Several of the taxa that increased in relative abundance over time were closely related to known degraders of alkane and other hydrocarbons. Alkane degradation has been proposed to be involved in PE degradation, and most of the organisms increasing in relative abundance over time harbored genes encoding proteins essential in alkane degradation, such as the genes alkB and CYP153, encoding an alkane monooxygenase and a cytochrome P450 alkane hydroxylase, respectively. Weight loss of PE sheets when incubated with these communities and chemical and electron microscopic analyses provided evidence for alteration of the PE surface over time. Taken together, these results provide evidence for the utilization of LDPE-associated compounds by the prokaryotic communities. This report identifies a group of genes potentially involved in the degradation of the LDPE polymeric structure and/or associated plastic additives in the ocean and describes a phylogenetically diverse community of plastic biofilm-dwelling microbes with the potential for utilizing LDPE-associated compounds as carbon and energy source. IMPORTANCE Low-density polyethylene (LDPE) is one of the most used plastics worldwide, and a large portion of it ends up in the ocean. Very little is known about its fate in the ocean and whether it can be biodegraded by microorganisms. By combining 2-year incubations with metagenomics, respiration measurements, and LDPE surface analysis, we identified bacteria and associated genes and metabolic pathways potentially involved in LDPE biodegradation. After 2 years of incubation, two of the microbial communities exhibited very similar taxonomic compositions mediating changes to the LDPE pieces they were incubated with. We provide evidence that there are plastic-biofilm dwelling bacteria in the ocean that might have the potential to degrade LDPE-associated compounds and that alkane degradation pathways might be involved.
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9
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Complete Genome Sequence of Stenotrophomonas maltophilia 1800, a New Bacterial Strain with Potential for Bioremediation of Oil-Contaminated Environments. Microbiol Resour Announc 2022; 11:e0111621. [PMID: 35175122 PMCID: PMC8852311 DOI: 10.1128/mra.01116-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Stenotrophomonas maltophilia strain 1800 was isolated from the effluent of an industrial oil refinery in Algeria. Its genome was sequenced using Illumina MiSeq (2 × 150-bp read pairs) and Oxford Nanopore (long reads) technologies and assembled using Unicycler. It is composed of one chromosome of 4.83 Mb.
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10
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Khot V, Zorz J, Gittins DA, Chakraborty A, Bell E, Bautista MA, Paquette AJ, Hawley AK, Novotnik B, Hubert CRJ, Strous M, Bhatnagar S. CANT-HYD: A Curated Database of Phylogeny-Derived Hidden Markov Models for Annotation of Marker Genes Involved in Hydrocarbon Degradation. Front Microbiol 2022; 12:764058. [PMID: 35069469 PMCID: PMC8767102 DOI: 10.3389/fmicb.2021.764058] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/08/2021] [Indexed: 02/04/2023] Open
Abstract
Many pathways for hydrocarbon degradation have been discovered, yet there are no dedicated tools to identify and predict the hydrocarbon degradation potential of microbial genomes and metagenomes. Here we present the Calgary approach to ANnoTating HYDrocarbon degradation genes (CANT-HYD), a database of 37 HMMs of marker genes involved in anaerobic and aerobic degradation pathways of aliphatic and aromatic hydrocarbons. Using this database, we identify understudied or overlooked hydrocarbon degradation potential in many phyla. We also demonstrate its application in analyzing high-throughput sequence data by predicting hydrocarbon utilization in large metagenomic datasets from diverse environments. CANT-HYD is available at https://github.com/dgittins/CANT-HYD-HydrocarbonBiodegradation.
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Affiliation(s)
- Varada Khot
- Energy Bioengineering and Geomicrobiology Group, Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Jackie Zorz
- Energy Bioengineering and Geomicrobiology Group, Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Daniel A Gittins
- Energy Bioengineering and Geomicrobiology Group, Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Anirban Chakraborty
- Energy Bioengineering and Geomicrobiology Group, Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Emma Bell
- Energy Bioengineering and Geomicrobiology Group, Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - María A Bautista
- Energy Bioengineering and Geomicrobiology Group, Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Alexandre J Paquette
- Energy Bioengineering and Geomicrobiology Group, Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Alyse K Hawley
- Energy Bioengineering and Geomicrobiology Group, Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Breda Novotnik
- Energy Bioengineering and Geomicrobiology Group, Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Casey R J Hubert
- Energy Bioengineering and Geomicrobiology Group, Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Marc Strous
- Energy Bioengineering and Geomicrobiology Group, Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Srijak Bhatnagar
- Energy Bioengineering and Geomicrobiology Group, Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
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11
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Affiliation(s)
- Judith Münch
- Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle, Saale, Germany
| | - Pascal Püllmann
- Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle, Saale, Germany
| | - Wuyuan Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West seventh Avenue, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, 32 West seventh Avenue, Tianjin 300308, China
| | - Martin J. Weissenborn
- Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle, Saale, Germany
- Institute of Chemistry, MartinLuther-University Halle-Wittenberg, Kurt-Mothes-Strasse 2, 06120, Halle, Saale, Germany
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12
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Schreiber L, Fortin N, Tremblay J, Wasserscheid J, Sanschagrin S, Mason J, Wright CA, Spear D, Johannessen SC, Robinson B, King T, Lee K, Greer CW. In situ microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine conditions. FEMS Microbiol Ecol 2021; 97:fiab082. [PMID: 34124756 PMCID: PMC8213973 DOI: 10.1093/femsec/fiab082] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 06/11/2021] [Indexed: 12/30/2022] Open
Abstract
Douglas Channel and the adjacent Hecate Strait (British Columbia, Canada) are part of a proposed route to ship diluted bitumen (dilbit). This study presents how two types of dilbit naturally degrade in this environment by using an in situ microcosm design based on dilbit-coated beads. We show that dilbit-associated n-alkanes were microbially biodegraded with estimated half-lives of 57-69 days. n-Alkanes appeared to be primarily degraded using the aerobic alkB, ladA and CYP153 pathways. The loss of dilbit polycyclic aromatic hydrocarbons (PAHs) was slower than of n-alkanes, with half-lives of 89-439 days. A biodegradation of PAHs could not be conclusively determined, although a significant enrichment of the phnAc gene (a marker for aerobic PAH biodegradation) was observed. PAH degradation appeared to be slower in Hecate Strait than in Douglas Channel. Microcosm-associated microbial communities were shaped by the presence of dilbit, deployment location and incubation time but not by dilbit type. Metagenome-assembled genomes of putative dilbit-degraders were obtained and could be divided into populations of early, late and continuous degraders. The majority of the identified MAGs could be assigned to the orders Flavobacteriales, Methylococcales, Pseudomonadales and Rhodobacterales. A high proportion of the MAGs represent currently unknown lineages or lineages with currently no cultured representative.
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Affiliation(s)
- Lars Schreiber
- Energy, Mining and Environment Research Center, National Research Council of Canada (NRC), 6100 Royalmount Ave, Montreal, QC H4P 2R2, Canada
| | - Nathalie Fortin
- Energy, Mining and Environment Research Center, National Research Council of Canada (NRC), 6100 Royalmount Ave, Montreal, QC H4P 2R2, Canada
| | - Julien Tremblay
- Energy, Mining and Environment Research Center, National Research Council of Canada (NRC), 6100 Royalmount Ave, Montreal, QC H4P 2R2, Canada
| | - Jessica Wasserscheid
- Energy, Mining and Environment Research Center, National Research Council of Canada (NRC), 6100 Royalmount Ave, Montreal, QC H4P 2R2, Canada
| | - Sylvie Sanschagrin
- Energy, Mining and Environment Research Center, National Research Council of Canada (NRC), 6100 Royalmount Ave, Montreal, QC H4P 2R2, Canada
| | - Jennifer Mason
- Centre for Offshore Oil, Gas and Energy Research (COOGER), Bedford Institute of Oceanography, Fisheries and Oceans Canada (DFO), 1 Challenger Drive, P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada
| | - Cynthia A Wright
- Institute of Ocean Sciences, Fisheries and Oceans Canada (DFO), 9860 West Saanich Road, P.O. Box 6000, Sidney, BC V8L 4B2, Canada
| | - David Spear
- Institute of Ocean Sciences, Fisheries and Oceans Canada (DFO), 9860 West Saanich Road, P.O. Box 6000, Sidney, BC V8L 4B2, Canada
| | - Sophia C Johannessen
- Institute of Ocean Sciences, Fisheries and Oceans Canada (DFO), 9860 West Saanich Road, P.O. Box 6000, Sidney, BC V8L 4B2, Canada
| | - Brian Robinson
- Centre for Offshore Oil, Gas and Energy Research (COOGER), Bedford Institute of Oceanography, Fisheries and Oceans Canada (DFO), 1 Challenger Drive, P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada
| | - Thomas King
- Centre for Offshore Oil, Gas and Energy Research (COOGER), Bedford Institute of Oceanography, Fisheries and Oceans Canada (DFO), 1 Challenger Drive, P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada
| | - Kenneth Lee
- Ecosystem Science, Fisheries and Oceans Canada (DFO), 200 Kent St, Ottawa,ON K1A 0E6, Canada
| | - Charles W Greer
- Energy, Mining and Environment Research Center, National Research Council of Canada (NRC), 6100 Royalmount Ave, Montreal, QC H4P 2R2, Canada
- Department of Natural Resource Sciences, McGill University, Macdonald-Stewart Building, McGill, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
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13
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Kong W, Zhao C, Gao X, Wang L, Tian Q, Liu Y, Xue S, Han Z, Chen F, Wang S. Characterization and Transcriptome Analysis of a Long-Chain n-Alkane-Degrading Strain Acinetobacter pittii SW-1. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18126365. [PMID: 34208299 PMCID: PMC8296198 DOI: 10.3390/ijerph18126365] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 11/16/2022]
Abstract
Strain sw-1, isolated from 7619-m seawater of the Mariana Trench, was identified as Acinetobacter pittii by 16S rRNA gene and whole-genome sequencing. A. pittii sw-1 was able to efficiently utilize long-chain n-alkanes (C18–C36), but not short- and medium-chain n-alkanes (C8–C16). The degradation rate of C20 was 91.25%, followed by C18, C22, C24, C32, and C36 with the degradation rates of 89.30%, 84.03%, 80.29%, 30.29%, and 13.37%, respectively. To investigate the degradation mechanisms of n-alkanes for this strain, the genome and the transcriptome analyses were performed. Four key alkane hydroxylase genes (alkB, almA, ladA1, and ladA2) were identified in the genome. Transcriptomes of strain sw-1 grown in C20 or CH3COONa (NaAc) as the sole carbon source were compared. The transcriptional levels of alkB and almA, respectively, increased 78.28- and 3.51-fold in C20 compared with NaAc, while ladA1 and ladA2 did not show obvious change. The expression levels of other genes involved in the synthesis of unsaturated fatty acids, permeases, membrane proteins, and sulfur metabolism were also upregulated, and they might be involved in n-alkane uptake. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) confirmed that alkB expression was significantly induced by C20, C24, and C32, and almA induction extent by C24 and C32 was higher than that with C20. Furthermore, ladA2 expression was only induced by C32, and ladA1 expression was not induced by any of n-alkanes. In addition, A. pittii sw-1 could grow with 0%–3% NaCl or 8 out of 10 kinds of the tested heavy metals and degrade n-alkanes at 15 °C. Taken together, these results provide comprehensive insights into the degradation of long-chain n-alkanes by Acinetobacter isolated from the deep ocean environment.
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Affiliation(s)
- Weina Kong
- Key Laboratory of Resources Biology and Biotechnology in Western China, School of Life Sciences, Northwest University, Ministry of Education, Xi’an 710069, China; (W.K.); (C.Z.); (L.W.); (Q.T.); (Y.L.); (S.X.)
| | - Cheng Zhao
- Key Laboratory of Resources Biology and Biotechnology in Western China, School of Life Sciences, Northwest University, Ministry of Education, Xi’an 710069, China; (W.K.); (C.Z.); (L.W.); (Q.T.); (Y.L.); (S.X.)
| | - Xingwang Gao
- Hulangmao Oil Production Area in No.3 Oil Production Plant of Changqing Oilfield Company, Yan’an 717500, China;
| | - Liping Wang
- Key Laboratory of Resources Biology and Biotechnology in Western China, School of Life Sciences, Northwest University, Ministry of Education, Xi’an 710069, China; (W.K.); (C.Z.); (L.W.); (Q.T.); (Y.L.); (S.X.)
| | - Qianqian Tian
- Key Laboratory of Resources Biology and Biotechnology in Western China, School of Life Sciences, Northwest University, Ministry of Education, Xi’an 710069, China; (W.K.); (C.Z.); (L.W.); (Q.T.); (Y.L.); (S.X.)
| | - Yu Liu
- Key Laboratory of Resources Biology and Biotechnology in Western China, School of Life Sciences, Northwest University, Ministry of Education, Xi’an 710069, China; (W.K.); (C.Z.); (L.W.); (Q.T.); (Y.L.); (S.X.)
| | - Shuwen Xue
- Key Laboratory of Resources Biology and Biotechnology in Western China, School of Life Sciences, Northwest University, Ministry of Education, Xi’an 710069, China; (W.K.); (C.Z.); (L.W.); (Q.T.); (Y.L.); (S.X.)
| | - Zhuang Han
- Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China;
| | - Fulin Chen
- Key Laboratory of Resources Biology and Biotechnology in Western China, School of Life Sciences, Northwest University, Ministry of Education, Xi’an 710069, China; (W.K.); (C.Z.); (L.W.); (Q.T.); (Y.L.); (S.X.)
- Correspondence: (F.C.); (S.W.)
| | - Shiwei Wang
- Key Laboratory of Resources Biology and Biotechnology in Western China, School of Life Sciences, Northwest University, Ministry of Education, Xi’an 710069, China; (W.K.); (C.Z.); (L.W.); (Q.T.); (Y.L.); (S.X.)
- Correspondence: (F.C.); (S.W.)
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Diallo MM, Vural C, Şahar U, Ozdemir G. Kurstakin molecules facilitate diesel oil assimilation by Acinetobacter haemolyticus strain 2SA through overexpression of alkane hydroxylase genes. ENVIRONMENTAL TECHNOLOGY 2021; 42:2031-2045. [PMID: 31752596 DOI: 10.1080/09593330.2019.1689301] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 10/30/2019] [Indexed: 06/10/2023]
Abstract
Biodegradation is a cost-effective process commonly used to eliminate many xenobiotic hydrocarbons such as diesel oils. However, their hydrophobic character reduces the biodegradation efficiency. In order to overcome this hurdle, kurstakins isolated from Bacillus thuringiensis strain 7SA were used as emulsifying agents. The influence of kurstakin molecules on diesel oil degradation by Acinetobacter haemolyticus strain 2SA was evaluated in the presence and absence of the aforementioned lipopeptide. The degradation rates and gene expressions of alkane hydroxylases were evaluated at days 4, 10, 14 and 21. Results showed that kurstakin molecules increased the hydrophobicity of 2SA. Moreover, diesel oil degradation activities were higher in the presence of kurstakin with 29%, 35%, 29% and 23% improvement at 4th, 10th, 14th and 21st day respectively. Statistical analysis indicated that the difference between the degradation rates in the presence and absence of kurstakin was significant with p = 0.03. The detection of three different hydroxylase genes namely alkB, almA and cyp153 in 2SA genome, might have allowed more efficient degradability of alkanes. According to the real-time PCR results, cyp153 was the most induced gene during diesel oil degradation in the presence and absence of kurstakin. Yet, the three genes demonstrated higher levels of expression in the presence of kurstakin when compared to its absence. This study showed that kurstakins enhance the diesel oil biodegradation rate by increasing the hydrophobicity of 2SA. In addition to their anti-fungal activities, kurstakins can be used as biosurfactant to increase biodegradation of diesel oil.
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Affiliation(s)
- Mamadou Malick Diallo
- Department of Biology, Basic and Industrial Microbiology Section, Ege University, Izmir, Turkey
| | - Caner Vural
- Department of Biology, Basic and Industrial Microbiology Section, Ege University, Izmir, Turkey
| | - Umut Şahar
- Department of Biology, Molecular Biology Section, Ege University, Izmir, Turkey
| | - Guven Ozdemir
- Department of Biology, Basic and Industrial Microbiology Section, Ege University, Izmir, Turkey
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Characterisation of hydrocarbon degradation, biosurfactant production, and biofilm formation in Serratia sp. Tan611: a new strain isolated from industrially contaminated environment in Algeria. Antonie van Leeuwenhoek 2021; 114:411-424. [PMID: 33587226 DOI: 10.1007/s10482-021-01527-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 01/22/2021] [Indexed: 10/22/2022]
Abstract
A novel bacterial strain was isolated from industrially contaminated waste water. In the presence of crude oil, this strain was shown to reduce the rate of total petroleum hydrocarbons (TPH) up to 97.10% in 24 h. This bacterium was subsequently identified by 16S rRNA gene sequence analysis and affiliated to the Serratia genus by the RDP classifier. Its genome was sequenced and annotated, and genes coding for catechol 1,2 dioxygenase and naphthalene 1,2-dioxygenase system involved in aromatic hydrocarbon catabolism, and LadA-type monooxygenases involved in alkane degradation, were identified. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of crude oil after biological treatment showed that Serratia sp. Tan611 strain was able to degrade n-alkanes (from C13 to C25). This bacterium was also shown to produce a biosurfactant, the emulsification index (E24) reaching 43.47% and 65.22%, against vegetable and crude oil, respectively. Finally, the formation of a biofilm was increased in the presence of crude oil. These observations make Serratia sp. Tan611 a good candidate for hydrocarbon bioremediation.
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Paul CE, Eggerichs D, Westphal AH, Tischler D, van Berkel WJH. Flavoprotein monooxygenases: Versatile biocatalysts. Biotechnol Adv 2021; 51:107712. [PMID: 33588053 DOI: 10.1016/j.biotechadv.2021.107712] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/27/2021] [Accepted: 02/06/2021] [Indexed: 12/13/2022]
Abstract
Flavoprotein monooxygenases (FPMOs) are single- or two-component enzymes that catalyze a diverse set of chemo-, regio- and enantioselective oxyfunctionalization reactions. In this review, we describe how FPMOs have evolved from model enzymes in mechanistic flavoprotein research to biotechnologically relevant catalysts that can be applied for the sustainable production of valuable chemicals. After a historical account of the development of the FPMO field, we explain the FPMO classification system, which is primarily based on protein structural properties and electron donor specificities. We then summarize the most appealing reactions catalyzed by each group with a focus on the different types of oxygenation chemistries. Wherever relevant, we report engineering strategies that have been used to improve the robustness and applicability of FPMOs.
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Affiliation(s)
- Caroline E Paul
- Biocatalysis, Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Daniel Eggerichs
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Dirk Tischler
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Willem J H van Berkel
- Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
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Lin JH, Zhang KC, Tao WY, Wang D, Li S. Geobacillus strains that have potential value in microbial enhanced oil recovery. Appl Microbiol Biotechnol 2019; 103:8339-8350. [PMID: 31501940 DOI: 10.1007/s00253-019-10115-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 08/26/2019] [Accepted: 08/30/2019] [Indexed: 12/31/2022]
Abstract
Bacteria from the genus Geobacillus are generally obligately thermophilic, with a unique bioenergy production capacity and unique enzymes. Geobacillus species were isolated primarily from hot springs, oilfields, and associated soils. They often exhibit unique survival patterns in these extreme oligotrophic environments. With the development of the microbial resources found in oilfields, Geobacillus spp. have been proven as valuable bacteria in many reports related to oilfields. After the isolation of Geobacillus by culture methods, more evidence was found that they possess the abilities of hydrocarbon utilization and bioemulsifier production. This paper mainly summarizes some characteristics of the Geobacillus species found in the oilfield environment, focusing on the inference and analysis of hydrocarbon degradation and bioemulsifier synthesis based on existing research, which may reveal their potential value in microbial enhanced oil recovery. It also provides references for understanding microbes in extreme environments.
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Affiliation(s)
- Jia-Hui Lin
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China
| | - Kun-Cheng Zhang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China
| | - Wei-Yi Tao
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China
| | - Dan Wang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China
| | - Shuang Li
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China.
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18
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Tourova TP, Sokolova DS, Semenova EM, Poltaraus AB, Nazina TN. Diversity of the alkB Genes of n-Alkane Biodegradation in Thermophilic Hydrocarbon-Oxidizing Bacteria of the Genera Geobacillus, Parageobacillus, and Aeribacillus. Microbiology (Reading) 2018. [DOI: 10.1134/s002626171803013x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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19
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Park C, Park W. Survival and Energy Producing Strategies of Alkane Degraders Under Extreme Conditions and Their Biotechnological Potential. Front Microbiol 2018; 9:1081. [PMID: 29910779 PMCID: PMC5992423 DOI: 10.3389/fmicb.2018.01081] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 05/07/2018] [Indexed: 11/17/2022] Open
Abstract
Many petroleum-polluted areas are considered as extreme environments because of co-occurrence of low and high temperatures, high salt, and acidic and anaerobic conditions. Alkanes, which are major constituents of crude oils, can be degraded under extreme conditions, both aerobically and anaerobically by bacteria and archaea of different phyla. Alkane degraders possess exclusive metabolic pathways and survival strategies, which involve the use of protein and RNA chaperones, compatible solutes, biosurfactants, and exopolysaccharide production for self-protection during harsh environmental conditions such as oxidative and osmotic stress, and ionic nutrient-shortage. Recent findings suggest that the thermophilic sulfate-reducing archaeon Archaeoglobus fulgidus uses a novel alkylsuccinate synthase for long-chain alkane degradation, and the thermophilic Candidatus Syntrophoarchaeum butanivorans anaerobically oxidizes butane via alkyl-coenzyme M formation. In addition, gene expression data suggest that extremophiles produce energy via the glyoxylate shunt and the Pta-AckA pathway when grown on a diverse range of alkanes under stress conditions. Alkane degraders possess biotechnological potential for bioremediation because of their unusual characteristics. This review will provide genomic and molecular insights on alkane degraders under extreme conditions.
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Affiliation(s)
- Chulwoo Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, South Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, South Korea
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20
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Tourova TP, Sokolova DS, Semenova EM, Shumkova ES, Korshunova AV, Babich TL, Poltaraus AB, Nazina TN. Detection of n-alkane biodegradation genes alkB and ladA in thermophilic hydrocarbon-oxidizing bacteria of the genera Aeribacillus and Geobacillus. Microbiology (Reading) 2016. [DOI: 10.1134/s0026261716060199] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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21
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Poltaraus AB, Sokolova DS, Grouzdev DS, Ivanov TM, Malakho SG, Korshunova AV, Tourova TP, Nazina TN. Draft Genome Sequence of Geobacillus subterraneus Strain K, a Hydrocarbon-Oxidizing Thermophilic Bacterium Isolated from a Petroleum Reservoir in Kazakhstan. GENOME ANNOUNCEMENTS 2016; 4:e00782-16. [PMID: 27491973 PMCID: PMC4974325 DOI: 10.1128/genomea.00782-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 06/10/2016] [Indexed: 11/20/2022]
Abstract
The draft genome sequence of Geobacillus subterraneus strain K, a thermophilic aerobic oil-oxidizing bacterium isolated from production water of the Uzen high-temperature oil field in Kazakhstan, is presented here. The genome is annotated for elucidation of the genomic and phenotypic diversity of thermophilic alkane-oxidizing bacteria.
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Affiliation(s)
- Andrey B Poltaraus
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Diyana S Sokolova
- Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Denis S Grouzdev
- Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Timophey M Ivanov
- Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Sophia G Malakho
- Federal State Budgetary Institution, "Federal Science Center for Physical Culture and Sport," Moscow, Russian Federation
| | - Alena V Korshunova
- Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Tatiyana P Tourova
- Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Tamara N Nazina
- Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
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22
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Abstract
The genus Geobacillus comprises a group of Gram-positive thermophilic bacteria, including obligate aerobes, denitrifiers, and facultative anaerobes that can grow over a range of 45-75°C. Originally classified as group five Bacillus spp., strains of Bacillus stearothermophilus came to prominence as contaminants of canned food and soon became the organism of choice for comparative studies of metabolism and enzymology between mesophiles and thermophiles. More recently, their catabolic versatility, particularly in the degradation of hemicellulose and starch, and rapid growth rates have raised their profile as organisms with potential for second-generation (lignocellulosic) biorefineries for biofuel or chemical production. The continued development of genetic tools to facilitate both fundamental investigation and metabolic engineering is now helping to realize this potential, for both metabolite production and optimized catabolism. In addition, this catabolic versatility provides a range of useful thermostable enzymes for industrial application. A number of genome-sequencing projects have been completed or are underway allowing comparative studies. These reveal a significant amount of genome rearrangement within the genus, the presence of large genomic islands encompassing all the hemicellulose utilization genes and a genomic island incorporating a set of long chain alkane monooxygenase genes. With G+C contents of 45-55%, thermostability appears to derive in part from the ability to synthesize protamine and spermine, which can condense DNA and raise its Tm.
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Affiliation(s)
- David J Studholme
- Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
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