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Lavecchia A, Fosso B, Engelen AH, Borin S, Manzari C, Picardi E, Pesole G, Placido A. Macroalgal microbiomes unveil a valuable genetic resource for halogen metabolism. MICROBIOME 2024; 12:47. [PMID: 38454513 PMCID: PMC10919026 DOI: 10.1186/s40168-023-01740-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 12/18/2023] [Indexed: 03/09/2024]
Abstract
BACKGROUND Macroalgae, especially reds (Rhodophyta Division) and browns (Phaeophyta Division), are known for producing various halogenated compounds. Yet, the reasons underlying their production and the fate of these metabolites remain largely unknown. Some theories suggest their potential antimicrobial activity and involvement in interactions between macroalgae and prokaryotes. However, detailed investigations are currently missing on how the genetic information of prokaryotic communities associated with macroalgae may influence the fate of organohalogenated molecules. RESULTS To address this challenge, we created a specialized dataset containing 161 enzymes, each with a complete enzyme commission number, known to be involved in halogen metabolism. This dataset served as a reference to annotate the corresponding genes encoded in both the metagenomic contigs and 98 metagenome-assembled genomes (MAGs) obtained from the microbiome of 2 red (Sphaerococcus coronopifolius and Asparagopsis taxiformis) and 1 brown (Halopteris scoparia) macroalgae. We detected many dehalogenation-related genes, particularly those with hydrolytic functions, suggesting their potential involvement in the degradation of a wide spectrum of halocarbons and haloaromatic molecules, including anthropogenic compounds. We uncovered an array of degradative gene functions within MAGs, spanning various bacterial orders such as Rhodobacterales, Rhizobiales, Caulobacterales, Geminicoccales, Sphingomonadales, Granulosicoccales, Microtrichales, and Pseudomonadales. Less abundant than degradative functions, we also uncovered genes associated with the biosynthesis of halogenated antimicrobial compounds and metabolites. CONCLUSION The functional data provided here contribute to understanding the still largely unexplored role of unknown prokaryotes. These findings support the hypothesis that macroalgae function as holobionts, where the metabolism of halogenated compounds might play a role in symbiogenesis and act as a possible defense mechanism against environmental chemical stressors. Furthermore, bacterial groups, previously never connected with organohalogen metabolism, e.g., Caulobacterales, Geminicoccales, Granulosicoccales, and Microtrichales, functionally characterized through MAGs reconstruction, revealed a biotechnologically relevant gene content, useful in synthetic biology, and bioprospecting applications. Video Abstract.
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Affiliation(s)
- Anna Lavecchia
- Department of Biosciences, Biotechnology and Environment, University of Bari "Aldo Moro", Via Orabona 4, Bari, 70124, Italy
| | - Bruno Fosso
- Department of Biosciences, Biotechnology and Environment, University of Bari "Aldo Moro", Via Orabona 4, Bari, 70124, Italy
| | - Aschwin H Engelen
- Center of Marine Sciences (CCMar), University of Algarve, Campus Gambelas, Faro, 8005-139, Portugal
| | - Sara Borin
- Department of Food, Environmental and Nutritional Sciences, University of Milan, Via Celoria 2, Milan, 20133, Italy
| | - Caterina Manzari
- Department of Biosciences, Biotechnology and Environment, University of Bari "Aldo Moro", Via Orabona 4, Bari, 70124, Italy
| | - Ernesto Picardi
- Department of Biosciences, Biotechnology and Environment, University of Bari "Aldo Moro", Via Orabona 4, Bari, 70124, Italy
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council of Italy, Via Giovanni Amendola, Bari, 122/O, 70126, Italy
| | - Graziano Pesole
- Department of Biosciences, Biotechnology and Environment, University of Bari "Aldo Moro", Via Orabona 4, Bari, 70124, Italy
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council of Italy, Via Giovanni Amendola, Bari, 122/O, 70126, Italy
| | - Antonio Placido
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council of Italy, Via Giovanni Amendola, Bari, 122/O, 70126, Italy.
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Macêdo WV, Poulsen JS, Zaiat M, Nielsen JL. Proteogenomics identification of TBBPA degraders in anaerobic bioreactor. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 310:119786. [PMID: 35872283 DOI: 10.1016/j.envpol.2022.119786] [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: 03/12/2022] [Revised: 06/29/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Tetrabromobisphenol A (TBBPA) is the most used flame retardant worldwide and has become a threat to aquatic ecosystems. Previous research into the degradation of this micropollutant in anaerobic bioreactors has suggested several identities of putative TBBPA degraders. However, the organisms actively degrading TBBPA under in situ conditions have so far not been identified. Protein-stable isotope probing (protein-SIP) has become a cutting-edge technique in microbial ecology for enabling the link between identity and function under in situ conditions. Therefore, it was hypothesized that combining protein-based stable isotope probing with metagenomics could be used to identify and provide genomic insight into the TBBPA-degrading organisms. The identified 13C-labelled peptides were found to belong to organisms affiliated to Phytobacter, Clostridium, Sporolactobacillus, and Klebsilla genera. The functional classification of identified labelled peptides revealed that TBBPA is not only transformed by cometabolic reactions, but also assimilated into the biomass. By application of the proteogenomics with labelled micropollutants (protein-SIP) and metagenome-assembled genomes, it was possible to extend the current perspective of the diversity of TBBPA degraders in wastewater and predict putative TBBPA degradation pathways. The study provides a link to the active TBBPA degraders and which organisms to favor for optimized biodegradation.
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Affiliation(s)
- Williane Vieira Macêdo
- Laboratory of Biological Processes, São Carlos School of Engineering, University of São Paulo (USP), 1100, João Dagnone Ave., Santa Angelina, Zip Code 13563-120, São Carlos, SP, Brazil; Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220, Aalborg, Denmark
| | - Jan Struckmann Poulsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220, Aalborg, Denmark
| | - Marcelo Zaiat
- Laboratory of Biological Processes, São Carlos School of Engineering, University of São Paulo (USP), 1100, João Dagnone Ave., Santa Angelina, Zip Code 13563-120, São Carlos, SP, Brazil
| | - Jeppe Lund Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220, Aalborg, Denmark.
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Yu F, Li Y, Wang H, Peng T, Wu YR, Hu Z. Microbial debromination of hexabromocyclododecanes. Appl Microbiol Biotechnol 2021; 105:4535-4550. [PMID: 34076715 DOI: 10.1007/s00253-021-11095-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/22/2020] [Accepted: 01/03/2021] [Indexed: 11/29/2022]
Abstract
Hexabromocyclododecanes (HBCDs), a new sort of brominated flame retardants (BFRs), are globally prevalent and recalcitrant toxic environmental pollutants. HBCDs have been found in many environmental media and even in the human body, leading to serious health concerns. HBCDs are biodegradable in the environment. By now, dozens of bacteria have been discovered with the ability to transform HBCDs. Microbial debromination of HBCDs is via HBr-elimination, HBr-dihaloelimination, and hydrolytic debromination. Biotic transformation of HBCDs yields many hydroxylated and lower brominated compounds which lack assessment of ecological toxicity. Bioremediation of HBCD pollution has only been applied in the laboratory. Here, we review the current knowledge about microbial debromination of HBCDs, aiming to promote the bioremediation applied in HBCD contaminated sites. KEY POINTS: • Microbial debromination of HBCDs is via hydrolytic debromination, HBr-elimination, and HBr-dihaloelimination. • Newly occurred halogenated contaminants such as HBCDs hitch the degradation pathway tamed by previously discharged anthropogenic organohalides. • Strategy that combines bioaugmentation with phytoremediation for bioremediation of HBCD pollution is promising.
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Affiliation(s)
- Fei Yu
- Department of Biology, Science College, Shantou University, Shantou, 515063, Guangdong Province, People's Republic of China
| | - Yuyang Li
- Department of Biology, Science College, Shantou University, Shantou, 515063, Guangdong Province, People's Republic of China
| | - Hui Wang
- Department of Biology, Science College, Shantou University, Shantou, 515063, Guangdong Province, People's Republic of China
| | - Tao Peng
- Department of Biology, Science College, Shantou University, Shantou, 515063, Guangdong Province, People's Republic of China
| | - Yi-Rui Wu
- Department of Biology, Science College, Shantou University, Shantou, 515063, Guangdong Province, People's Republic of China
| | - Zhong Hu
- Department of Biology, Science College, Shantou University, Shantou, 515063, Guangdong Province, People's Republic of China.
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Ang TF, Maiangwa J, Salleh AB, Normi YM, Leow TC. Dehalogenases: From Improved Performance to Potential Microbial Dehalogenation Applications. Molecules 2018; 23:E1100. [PMID: 29735886 PMCID: PMC6100074 DOI: 10.3390/molecules23051100] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/07/2018] [Accepted: 04/09/2018] [Indexed: 11/16/2022] Open
Abstract
The variety of halogenated substances and their derivatives widely used as pesticides, herbicides and other industrial products is of great concern due to the hazardous nature of these compounds owing to their toxicity, and persistent environmental pollution. Therefore, from the viewpoint of environmental technology, the need for environmentally relevant enzymes involved in biodegradation of these pollutants has received a great boost. One result of this great deal of attention has been the identification of environmentally relevant bacteria that produce hydrolytic dehalogenases—key enzymes which are considered cost-effective and eco-friendly in the removal and detoxification of these pollutants. These group of enzymes catalyzing the cleavage of the carbon-halogen bond of organohalogen compounds have potential applications in the chemical industry and bioremediation. The dehalogenases make use of fundamentally different strategies with a common mechanism to cleave carbon-halogen bonds whereby, an active-site carboxylate group attacks the substrate C atom bound to the halogen atom to form an ester intermediate and a halide ion with subsequent hydrolysis of the intermediate. Structurally, these dehalogenases have been characterized and shown to use substitution mechanisms that proceed via a covalent aspartyl intermediate. More so, the widest dehalogenation spectrum of electron acceptors tested with bacterial strains which could dehalogenate recalcitrant organohalides has further proven the versatility of bacterial dehalogenators to be considered when determining the fate of halogenated organics at contaminated sites. In this review, the general features of most widely studied bacterial dehalogenases, their structural properties, basis of the degradation of organohalides and their derivatives and how they have been improved for various applications is discussed.
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Affiliation(s)
- Thiau-Fu Ang
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Jonathan Maiangwa
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Abu Bakar Salleh
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Institute of Bioscience, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Yahaya M Normi
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Thean Chor Leow
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Institute of Bioscience, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
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A Mechanistic Analysis of Enzymatic Degradation of Organohalogen Compounds. Biosci Biotechnol Biochem 2014; 75:189-98. [DOI: 10.1271/bbb.100746] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Improvement of NADPH bioavailability in Escherichia coli by replacing NAD(+)-dependent glyceraldehyde-3-phosphate dehydrogenase GapA with NADP (+)-dependent GapB from Bacillus subtilis and addition of NAD kinase. J Ind Microbiol Biotechnol 2013; 40:1449-60. [PMID: 24048943 DOI: 10.1007/s10295-013-1335-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 08/28/2013] [Indexed: 02/03/2023]
Abstract
Enzymatic synthesis of some industrially important compounds depends heavily on cofactor NADPH as the reducing agent. This is especially true in the synthesis of chiral compounds that are often used as pharmaceutical intermediates to generate the correct stereochemistry in bioactive products. The high cost and technical difficulty of cofactor regeneration often pose a challenge for such biocatalytic reactions. In this study, to increase NADPH bioavailability, the native NAD(+)-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gapA gene in Escherichia coli was replaced with a NADP(+)-dependent gapB from Bacillus subtilis. To overcome the limitation of NADP(+) availability, E. coli NAD kinase, nadK was also coexpressed with gapB. The recombinant strains were then tested in three reporting systems: biosynthesis of lycopene, oxidation of cyclohexanone with cyclohexanone monooxygenase (CHMO), and an anaerobic system utilizing 2-haloacrylate reductase (CAA43). In all the reporting systems, replacing NAD(+)-dependent GapA activity with NADP(+)-dependent GapB activity increased the synthesis of NADPH-dependent compounds. The increase was more pronounced when NAD kinase was also overexpressed in the case of the one-step reaction catalyzed by CAA43 which approximately doubled the product yield. These results validate this novel approach to improve NADPH bioavailability in E. coli and suggest that the strategy can be applied in E. coli or other bacterium-based production of NADPH-dependent compounds.
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Jan J, Martinez I, Wang Y, Bennett GN, San KY. Metabolic engineering and transhydrogenase effects on NADPH availability in Escherichia coli. Biotechnol Prog 2013; 29:1124-30. [PMID: 23794523 DOI: 10.1002/btpr.1765] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 04/08/2013] [Indexed: 11/08/2022]
Abstract
The synthesis of several industrially useful compounds are cofactor-dependent, requiring reducing equivalents like NADPH in enzymatic reactions leading up to the synthesis of high-value compounds like polymers, chiral alcohols, and antibiotics. However, NADPH is costly and has limited intracellular availability. This study focuses on the study of the effect of the two transhydrogenase enzymes of Escherichia coli, PntAB and UdhA (SthA) on reducing equivalents-dependent biosynthesis. The production of (S)-2-chloropropionate from 2-chloroacrylate is used as a model system for monitoring NADPH availability because 2-haloacrylate reductase, the enzyme catalyzing the one-step conversion to (S)-2-chloropropionate in the synthesis pathway, requires NADPH as a cofactor. Results suggest that the presence of UdhA increases product yield and NADPH availability while the presence of PntAB has the opposite effect. A maximum product yield of 1.4 mol product/mol glucose was achieved aerobically in a pnt-deletion strain with udhA overexpression, a 150% improvement over the wild-type control strain.
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Affiliation(s)
- Joanna Jan
- Dept. of Bioengineering, Rice University, Houston, TX
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Wang Y, San KY, Bennett GN. Improvement of NADPH bioavailability in Escherichia coli through the use of phosphofructokinase deficient strains. Appl Microbiol Biotechnol 2013; 97:6883-93. [PMID: 23558585 DOI: 10.1007/s00253-013-4859-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 03/11/2013] [Accepted: 03/13/2013] [Indexed: 11/26/2022]
Abstract
NADPH-dependent reactions play important roles in production of industrially valuable compounds. In this study, we used phosphofructokinase (PFK)-deficient strains to direct fructose-6-phosphate to be oxidized through the pentose phosphate pathway (PPP) to increase NADPH generation. pfkA or pfkB single deletion and double-deletion strains were tested for their ability to produce lycopene. Since lycopene biosynthesis requires many NADPH, levels of lycopene were compared in a set of isogenic strains, with the pfkA single deletion strain showing the highest lycopene yield. Using another NADPH-requiring process, a one-step reduction reaction of 2-chloroacrylate to 2-chloropropionic acid by 2-haloacrylate reductase, the pfkA pfkB double-deletion strain showed the highest yield of 2-chloropropionic acid product. The combined effect of glucose-6-phosphate dehydrogenase overexpression or lactate dehydrogenase deletion with PFK deficiency on NADPH bioavailability was also studied. The results indicated that the flux distribution of fructose-6-phosphate between glycolysis and the pentose phosphate pathway determines the amount of NAPDH available for reductive biosynthesis.
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Affiliation(s)
- Yipeng Wang
- Department of Biochemistry and Cell Biology, MS-140, Rice University, 6100 Main Street, Houston, TX 77005-1892, USA
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Arif MI, Samin G, van Leeuwen JGE, Oppentocht J, Janssen DB. Novel dehalogenase mechanism for 2,3-dichloro-1-propanol utilization in Pseudomonas putida strain MC4. Appl Environ Microbiol 2012; 78:6128-36. [PMID: 22752160 PMCID: PMC3416625 DOI: 10.1128/aem.00760-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 06/14/2012] [Indexed: 11/20/2022] Open
Abstract
A Pseudomonas putida strain (MC4) that can utilize 2,3-dichloro-1-propanol (DCP) and several aliphatic haloacids and haloalcohols as sole carbon and energy source for growth was isolated from contaminated soil. Degradation of DCP was found to start with oxidation and concomitant dehalogenation catalyzed by a 72-kDa monomeric protein (DppA) that was isolated from cell lysate. The dppA gene was cloned from a cosmid library and appeared to encode a protein equipped with a signal peptide and that possessed high similarity to quinohemoprotein alcohol dehydrogenases (ADHs), particularly ADH IIB and ADH IIG from Pseudomonas putida HK. This novel dehalogenating dehydrogenase has a broad substrate range, encompassing a number of nonhalogenated alcohols and haloalcohols. With DCP, DppA exhibited a k(cat) of 17 s(-1). (1)H nuclear magnetic resonance experiments indicated that DCP oxidation by DppA in the presence of 2,6-dichlorophenolindophenol (DCPIP) and potassium ferricyanide [K(3)Fe(CN)(6)] yielded 2-chloroacrolein, which was oxidized to 2-chloroacrylic acid.
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Affiliation(s)
- Muhammad Irfan Arif
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
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Samin G, Janssen DB. Transformation and biodegradation of 1,2,3-trichloropropane (TCP). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2012; 19:3067-78. [PMID: 22875418 PMCID: PMC3414701 DOI: 10.1007/s11356-012-0859-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 03/09/2012] [Indexed: 05/04/2023]
Abstract
PURPOSE 1,2,3-Trichloropropane (TCP) is a persistent groundwater pollutant and a suspected human carcinogen. It is also is an industrial chemical waste that has been formed in large amounts during epichlorohydrin manufacture. In view of the spread of TCP via groundwater and its toxicity, there is a need for cheap and efficient technologies for the cleanup of TCP-contaminated sites. In situ or on-site bioremediation of TCP is an option if biodegradation can be achieved and stimulated. This paper presents an overview of methods for the remediation of TCP-contaminated water with an emphasis on the possibilities of biodegradation. CONCLUSIONS Although TCP is a xenobiotic chlorinated compound of high chemical stability, a number of abiotic and biotic conversions have been demonstrated, including abiotic oxidative conversion in the presence of a strong oxidant and reductive conversion by zero-valent zinc. Biotransformations that have been observed include reductive dechlorination, monooxygenase-mediated cometabolism, and enzymatic hydrolysis. No natural organisms are known that can use TCP as a carbon source for growth under aerobic conditions, but anaerobically TCP may serve as electron acceptor. The application of biodegradation is hindered by low degradation rates and incomplete mineralization. Protein engineering and genetic modification can be used to obtain microorganisms with enhanced TCP degradation potential.
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Affiliation(s)
- Ghufrana Samin
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Dick B. Janssen
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
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Abstract
Microorganisms have been used for decades as sources of antibiotics, vitamins and enzymes and for the production of fermented foods and chemicals. In the 21st century microorganisms will play a vital role in addressing some of the problems faced by mankind. In this article three of the current applications in which microbes have a significant role to play are highlighted: the discovery of new antibiotics, manufacture of biofuels and bioplastics, and production of fine chemicals via biotransformation.
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Affiliation(s)
- Cormac D Murphy
- School of Biomolecular and Biomedical Science, Centre for Synthesis and Chemical Biology, Ardmore House, University College Dublin, Dublin 4, Ireland.
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Sullivan MJ, Curson ARJ, Shearer N, Todd JD, Green RT, Johnston AWB. Unusual regulation of a leaderless operon involved in the catabolism of dimethylsulfoniopropionate in Rhodobacter sphaeroides. PLoS One 2011; 6:e15972. [PMID: 21249136 PMCID: PMC3017554 DOI: 10.1371/journal.pone.0015972] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 12/01/2010] [Indexed: 11/20/2022] Open
Abstract
Rhodobacter sphaeroides strain 2.4.1 is a widely studied bacterium that has recently been shown to cleave the abundant marine anti-stress molecule dimethylsulfoniopropionate (DMSP) into acrylate plus gaseous dimethyl sulfide. It does so by using a lyase encoded by dddL, the promoter-distal gene of a three-gene operon, acuR-acuI-dddL. Transcription of the operon was enhanced when cells were pre-grown with the substrate DMSP, but this induction is indirect, and requires the conversion of DMSP to the product acrylate, the bona fide co-inducer. This regulation is mediated by the product of the promoter-proximal gene acuR, a transcriptional regulator in the TetR family. AcuR represses the operon in the absence of acrylate, but this is relieved by the presence of the co-inducer. Another unusual regulatory feature is that the acuR-acuI-dddL mRNA transcript is leaderless, such that acuR lacks a Shine-Dalgarno ribosomal binding site and 5′-UTR, and is translated at a lower level compared to the downstream genes. This regulatory unit may be quite widespread in bacteria, since several other taxonomically diverse lineages have adjacent acuR-like and acuI-like genes; these operons also have no 5′ leader sequences or ribosomal binding sites and their predicted cis-acting regulatory sequences resemble those of R. sphaeroides acuR-acuI-dddL.
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Affiliation(s)
- Matthew J. Sullivan
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Andrew R. J. Curson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Neil Shearer
- Institute of Food Research, Norwich Research Park, Norwich, United Kingdom
| | - Jonathan D. Todd
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Robert T. Green
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
- Institute of Food Research, Norwich Research Park, Norwich, United Kingdom
| | - Andrew W. B. Johnston
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
- * E-mail:
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2-haloacrylate hydratase, a new class of flavoenzyme that catalyzes the addition of water to the substrate for dehalogenation. Appl Environ Microbiol 2010; 76:6032-7. [PMID: 20656877 DOI: 10.1128/aem.00334-10] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enzymes catalyzing the conversion of organohalogen compounds are useful in the chemical industry and environmental technology. Here we report the occurrence of a new reduced flavin adenine dinucleotide (FAD) (FADH(2))-dependent enzyme that catalyzes the removal of a halogen atom from an unsaturated aliphatic organohalogen compound by the addition of a water molecule to the substrate. A soil bacterium, Pseudomonas sp. strain YL, inducibly produced a protein named Caa67(YL) when the cells were grown on 2-chloroacrylate (2-CAA). The caa67(YL) gene encoded a protein of 547 amino acid residues (M(r) of 59,301), which shared weak but significant sequence similarity with various flavoenzymes and contained a nucleotide-binding motif. We found that 2-CAA is converted into pyruvate when the reaction was carried out with purified Caa67(YL) in the presence of FAD and a reducing agent [NAD(P)H or sodium dithionite] under anaerobic conditions. The reducing agent was not stoichiometrically consumed during this reaction, suggesting that FADH(2) is conserved by regeneration in the catalytic cycle. When the reaction was carried out in the presence of H(2)(18)O, [(18)O]pyruvate was produced. These results indicate that Caa67(YL) catalyzes the hydration of 2-CAA to form 2-chloro-2-hydroxypropionate, which is chemically unstable and probably spontaneously dechlorinated to form pyruvate. 2-Bromoacrylate, but not other 2-CAA analogs such as acrylate and methacrylate, served as the substrate of Caa67(YL). Thus, we named this new enzyme 2-haloacrylate hydratase. The enzyme is very unusual in that it requires the reduced form of FAD for hydration, which involves no net change in the redox state of the coenzyme or substrate.
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Kurata A, Fujita M, Mowafy AM, Kamachi H, Kurihara T, Esaki N. Production of (S)-2-chloropropionate by asymmetric reduction of 2-chloroacrylate with 2-haloacrylate reductase coupled with glucose dehydrogenase. J Biosci Bioeng 2008; 105:429-31. [PMID: 18499064 DOI: 10.1263/jbb.105.429] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Accepted: 01/22/2008] [Indexed: 11/17/2022]
Abstract
(S)-2-Chloropropionate is a synthetic intermediate for phenoxypropionic acid herbicides. We constructed a system for asymmetric reduction of 2-chloroacrylate to produce (S)-2-chloropropionate with recombinant Escherichia coli cells producing 2-haloacrylate reductase from Burkholderia sp. WS and an NADPH regeneration system. The system provided 37.4 g/l (S)-2-chloropropionate in more than 99.9%e.e.
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Affiliation(s)
- Atsushi Kurata
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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Kurihara T, Esaki N. Bacterial hydrolytic dehalogenases and related enzymes: Occurrences, reaction mechanisms, and applications. CHEM REC 2008; 8:67-74. [DOI: 10.1002/tcr.20141] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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