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Gaid M, Pöpke D, Reinhard A, Berzhanova R, Mukasheva T, Urich T, Mikolasch A. Characterization of the Mycoremediation of n-Alkanes and Branched-Chain Alkanes by Filamentous Fungi from Oil-Polluted Soil Samples in Kazakhstan. Microorganisms 2023; 11:2195. [PMID: 37764039 PMCID: PMC10534712 DOI: 10.3390/microorganisms11092195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/29/2023] Open
Abstract
For decades, researchers have focused on containing terrestrial oil pollution. The heterogeneity of soils, with immense microbial diversity, inspires them to transform pollutants and find cost-effective bioremediation methods. In this study, the mycoremediation potentials of five filamentous fungi isolated from polluted soils in Kazakhstan were investigated for their degradability of n-alkanes and branched-chain alkanes as sole carbon and energy sources. Dry weight estimation and gas chromatography-mass spectrometry (GC-MS) monitored the growth and the changes in the metabolic profile during degradation, respectively. Penicillium javanicum SBUG-M1741 and SBUG-M1742 oxidized medium-chain alkanes almost completely through mono- and di-terminal degradation. Pristane degradation by P. javanicum SBUG-M1741 was >95%, while its degradation with Purpureocillium lilacinum SBUG-M1751 was >90%. P. lilacinum SBUG-M1751 also exhibited the visible degradation potential of tetradecane and phytane, whereby in the transformation of phytane, both the mono- and di-terminal degradation pathways as well as α- and ß-oxidation steps could be described. Scedosporium boydii SBUG-M1749 used both mono- and di-terminal degradation pathways for n-alkanes, but with poor growth. Degradation of pristane by Fusarium oxysporum SBUG-M1747 followed the di-terminal oxidation mechanism, resulting in one dicarboxylic acid. These findings highlight the role of filamentous fungi in containing oil pollution and suggest possible degradation pathways.
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Affiliation(s)
- Mariam Gaid
- Institute of Microbiology, University Greifswald, Felix-Hausdorff-Straße 8, 17489 Greifswald, Germany
| | - Doreen Pöpke
- Institute of Microbiology, University Greifswald, Felix-Hausdorff-Straße 8, 17489 Greifswald, Germany
| | - Anne Reinhard
- Institute of Microbiology, University Greifswald, Felix-Hausdorff-Straße 8, 17489 Greifswald, Germany
| | - Ramza Berzhanova
- Department of Biology and Biotechnology, Al-Farabi Kazakh National University, Al-Farabi Ave. 71, Almaty 050040, Kazakhstan
| | - Togzhan Mukasheva
- Department of Biology and Biotechnology, Al-Farabi Kazakh National University, Al-Farabi Ave. 71, Almaty 050040, Kazakhstan
| | - Tim Urich
- Institute of Microbiology, University Greifswald, Felix-Hausdorff-Straße 8, 17489 Greifswald, Germany
| | - Annett Mikolasch
- Institute of Microbiology, University Greifswald, Felix-Hausdorff-Straße 8, 17489 Greifswald, Germany
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Omokpariola DO, Nduka JK, Kelle HI, Mgbemena NM, Iduseri EO. Chemometrics, health risk assessment and probable sources of soluble total petroleum hydrocarbons in atmospheric rainwater, Rivers State, Nigeria. Sci Rep 2022; 12:11829. [PMID: 35821234 PMCID: PMC9276798 DOI: 10.1038/s41598-022-15677-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 06/28/2022] [Indexed: 11/30/2022] Open
Abstract
Total petroleum hydrocarbons (TPHs)-(aliphatic and aromatic) were analysed for in atmospheric rainwater between April-June; July-August; September-October depicting early, mid, late rain of 2019. Sampling at Rumuodomaya/Rumuodome and Ogale in Rivers State using basins fastened to a Table 2M above ground and 120 M from high features, Rainwater was analysed after treatment using Agilent GC-FID. Results show cumulative TPHs at R/R were 56.6551 mg/L, 39.5201 mg/L and 7.2283 mg/L, Ogale: 9.1217 mg/L, 59.4923 mg/L and 21.9825 mg/L. Aliphatic hydrocarbons: C5-C8 were < 1, low contamination, other carbon aggregates (C9-C16, C17-C35, and C36-C40) indicate high contamination. Chemometric assessment showed high contamination. TPHs aggregates at Rumuodomaya/Rumuodome were-C8-C11 (1.034 and 1.005) early rain, C18-C25 and C26-C33 has Carbon preference index of 1.287 and 1.630 (mid-rain), C26-C33 has CPI of 1.288 (late-rain), Ogale area, C26-C33 has CPI of 1.732 (early-rain), mid-rain C8-C11 (2.768) and C12-C17 (5.368). Pristane/phytane ratio indicated biogenic and pyrogenic sources. Average carbon length of TPHs for odd n-alkanes were C9-C11 (9.446) and C35-C39 (38.980), C9-C11(10.238), C35-C39 (36.510); C9-C11 (10.240) and C35-C39 (36.934). Average daily intake depicted possible health issues for children and adults as hazard index > 1 for aromatics.
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Affiliation(s)
- Daniel Omeodisemi Omokpariola
- Environmental Chemistry and Toxicology Unit, Pure and Industrial Chemistry Department, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Nigeria
| | - John Kanayochukwu Nduka
- Environmental Chemistry and Toxicology Unit, Pure and Industrial Chemistry Department, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Nigeria.
| | - Henrietta Ijeoma Kelle
- Department of Chemistry, Faculty of Science, National Open University of Nigeria, Abuja, Nigeria
| | - Nkoli MaryAnn Mgbemena
- Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria
| | - Emily Osa Iduseri
- Department of Environmental Sciences, Faculty of Science, National Open University of Nigeria, Abuja, Nigeria
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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Alvarez HM, Hernández MA, Lanfranconi MP, Silva RA, Villalba MS. Rhodococcus as Biofactories for Microbial Oil Production. Molecules 2021; 26:molecules26164871. [PMID: 34443455 PMCID: PMC8401914 DOI: 10.3390/molecules26164871] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 01/20/2023] Open
Abstract
Bacteria belonging to the Rhodococcus genus are frequent components of microbial communities in diverse natural environments. Some rhodococcal species exhibit the outstanding ability to produce significant amounts of triacylglycerols (TAG) (>20% of cellular dry weight) in the presence of an excess of the carbon source and limitation of the nitrogen source. For this reason, they can be considered as oleaginous microorganisms. As occurs as well in eukaryotic single-cell oil (SCO) producers, these bacteria possess specific physiological properties and molecular mechanisms that differentiate them from other microorganisms unable to synthesize TAG. In this review, we summarized several of the well-characterized molecular mechanisms that enable oleaginous rhodococci to produce significant amounts of SCO. Furthermore, we highlighted the ability of these microorganisms to degrade a wide range of carbon sources coupled to lipogenesis. The qualitative and quantitative oil production by rhodococci from diverse industrial wastes has also been included. Finally, we summarized the genetic and metabolic approaches applied to oleaginous rhodococci to improve SCO production. This review provides a comprehensive and integrating vision on the potential of oleaginous rhodococci to be considered as microbial biofactories for microbial oil production.
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Crotta Asis A, Savoretti F, Cabruja M, Gramajo H, Gago G. Characterization of key enzymes involved in triacylglycerol biosynthesis in mycobacteria. Sci Rep 2021; 11:13257. [PMID: 34168231 PMCID: PMC8225852 DOI: 10.1038/s41598-021-92721-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 06/08/2021] [Indexed: 02/05/2023] Open
Abstract
Phosphatidic acid phosphatase (PAP) catalyzes the dephosphorylation of phosphatidic acid (PA) yielding diacylglycerol (DAG), the lipid precursor for triacylglycerol (TAG) biosynthesis. PAP activity has a key role in the regulation of PA flux towards TAG or glycerophospholipid synthesis. In this work we have characterized two Mycobacterium smegmatis genes encoding for functional PAP proteins. Disruption of both genes provoked a sharp reduction in de novo TAG biosynthesis in early growth phase cultures under stress conditions. In vivo labeling experiments demonstrated that TAG biosynthesis was restored in the ∆PAP mutant when bacteria reached exponential growth phase, with a concomitant reduction of phospholipid synthesis. In addition, comparative lipidomic analysis showed that the ∆PAP strain had increased levels of odd chain fatty acids esterified into TAGs, suggesting that the absence of PAP activity triggered other rearrangements of lipid metabolism, like phospholipid recycling, in order to maintain the wild type levels of TAG. Finally, the lipid changes observed in the ∆PAP mutant led to defective biofilm formation. Understanding the interaction between TAG synthesis and the lipid composition of mycobacterial cell envelope is a key step to better understand how lipid homeostasis is regulated during Mycobacterium tuberculosis infection.
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Affiliation(s)
- Agostina Crotta Asis
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Franco Savoretti
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Matías Cabruja
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
- Stanford University, Stanford, USA
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
| | - Gabriela Gago
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
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6
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Abstract
Biological wax esters offer a sustainable, renewable and biodegradable alternative to many fossil fuel derived chemicals including plastics and paraffins. Many species of bacteria accumulate waxes with similar structure and properties to highly desirable animal and plant waxes such as Spermaceti and Jojoba oils, the use of which is limited by resource requirements, high cost and ethical concerns. While bacterial fermentations overcome these issues, a commercially viable bacterial wax production process would require high yields and renewable, affordable feedstock to make it economically competitive and environmentally beneficial. This review describes recent progress in wax ester generation in both wild type and genetically engineered bacteria, with a focus on comparing substrates and quantifying obtained waxes. The full breadth of wax accumulating species is discussed, with emphasis on species generating high yields and utilising renewable substrates. Key areas of the field that have, thus far, received limited attention are highlighted, such as waste stream valorisation, mixed microbial cultures and efficient wax extraction, as, until effectively addressed, these will slow progress in creating commercially viable wax production methods.
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Synthesis of polyhydroxyalkanoates through the biodegradation of poly(cis-1,4-isoprene) rubber. J Biosci Bioeng 2019; 127:360-365. [DOI: 10.1016/j.jbiosc.2018.08.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/17/2018] [Accepted: 08/29/2018] [Indexed: 11/19/2022]
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Tortone CA, Oriani DS, Staskevich AS, Oriani AS, Gino LM, Marfil MJ, Nava Vargas A, Gioffré AK, Zumárraga MJ. [Species diversity of non-tuberculous mycobacteria isolated from aquatic environments of General Pico city, Province of La Pampa (Argentina)]. Rev Argent Microbiol 2018; 51:259-267. [PMID: 30579706 DOI: 10.1016/j.ram.2018.08.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 07/26/2018] [Accepted: 08/06/2018] [Indexed: 11/16/2022] Open
Abstract
Non-tuberculous mycobacteria (NTM) are studied not only for their importance as emerging opportunistic pathogens but also for their applications in biotechnology and bioremediation. Our aim was to determine the occurrence and diversity of mycobacteria in different aquatic habitats of General Pico city, Province of La Pampa. The percentage of samples with positive cultures for mycobacteria were the following: 37.5% recovered from the water supply distribution system; 32.6% from the aquifer that supplies water to the distribution system; 36.8% from rain water; 53.1% from the two wetlands in the area of influence; 80% from indoor swimming pools; and 33.3% from water fountains in downtown public squares. Of the 90 NTM isolates, 8.9% could not be identified at the species level with any of the used methods, phenotypic tests and molecular methods. Mycobacterium fortuitum and Mycobacterium gordonae were the most frequently isolated species. Some of the identified species such as, M. fortuitum, M. gordonae, M. intracellulare, M. vaccae, M. lentiflavum and M. nonchromogenicum, have been reported in cases of mycobacteriosis in Argentina. Mycobacteria with values higher than 0.8mg/ml of residual active chlorine were not recovered from the drinking water supply network, whereas in the swimming pools the presence of up to 1.5mg/l was not a constraint. Based on our results, the presence of mycobacteria in aquatic environments is close to 35% and their occurrence and diversity is affected both by contact with man and his activities as well as by the existence of animal life.
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Affiliation(s)
- Claudia A Tortone
- Cátedra de Bacteriología y Micología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Pampa, General Pico, La Pampa, Argentina.
| | - Delia S Oriani
- Cátedra de Bacteriología y Micología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Pampa, General Pico, La Pampa, Argentina
| | - Ana S Staskevich
- Cátedra de Bacteriología y Micología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Pampa, General Pico, La Pampa, Argentina
| | - Alejandra S Oriani
- Departamento de Biología, Bioquímica y Farmacia-Universidad Nacional del Sur, Bahía Blanca, Provincia de Buenos Aires, Argentina
| | - Lilia M Gino
- Cátedra de Parasitología y Enfermedades Parasitarias, Facultad de Ciencias Veterinarias, Universidad Nacional de La Pampa, General Pico, La Pampa, Argentina
| | - María J Marfil
- Instituto Nacional de Tecnología Agropecuaria (CICVyA/INTA), Hurlingham, Buenos Aires, Argentina
| | | | - Andrea K Gioffré
- Instituto Nacional de Tecnología Agropecuaria (CICVyA/INTA), Hurlingham, Buenos Aires, Argentina
| | - Martín J Zumárraga
- Instituto Nacional de Tecnología Agropecuaria (CICVyA/INTA), Hurlingham, Buenos Aires, Argentina
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Abstract
Two bacterial strains phylogenetically identified as Pseudomonas aeruginosa strains RM1 and SK1 displayed extensive degradation ability on waste engine oil (SAE 40W) in batch cultures. Spectrophotometric analysis revealed the presence of various heavy metals such as lead, chromium and nickel in the waste engine oil. The rate of degradation of waste engine oil by the isolates, for the first 12 days and the last 9 days were 66.3, 31.6 mg l−1 day−1 and 69.6, 40.0 mg l−1 day−1 for strains RM1 and SK1, respectively. Gas chromatographic (GC) analyses of residual waste engine oil, revealed that 66.58, 89.06 % and 63.40, 90.75 % of the initial concentration of the waste engine oil were degraded by strains RM1 and SK1 within 12 and 21 days. GC fingerprints of the waste engine oil after 12 days of incubation of strains RM1 and SK1 showed total disappearance of C15, C23, C24, C25 and C26 hydrocarbon fractions as well as drastic reductions of C13, C14, C16 and PAHs fractions such as C19-anthracene and C22-pyrene. At the end of 21 days incubation, total disappearance of C17-pristane, C22-pyrene, one of the C19-anthracene and significant reduction of C18-phytane (97.2 %, strain RM1; 95.1 %, strain SK1) fractions were observed. In addition, <10 % of Day 0 values of medium fraction ranges C13, and C16 were discernible after 21 days. This study has established the potentials of P. aeruginosa strains RM1 and SK1 in the degradation of aliphatic, aromatic and branched alkane components of waste engine oils.
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Lanfranconi MP, Alvarez AF, Alvarez HM. Identification of genes coding for putative wax ester synthase/diacylglycerol acyltransferase enzymes in terrestrial and marine environments. AMB Express 2015; 5:128. [PMID: 26228353 PMCID: PMC4520822 DOI: 10.1186/s13568-015-0128-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 07/06/2015] [Indexed: 11/29/2022] Open
Abstract
Synthesis of neutral lipids such as triacylglycerols (TAG) and wax esters (WE) is catalyzed in bacteria by wax ester synthase/diacylglycerol acyltransferase enzymes (WS/DGAT). We investigated
the diversity of genes encoding this enzyme in contrasting natural environments from Patagonia (Argentina). The content of petroleum hydrocarbons in samples collected from oil-producing areas was measured. PCR-based analysis covered WS/DGAT occurrence in marine sediments and soil. No product was obtained in seawater samples. All clones retrieved from marine sediments affiliated with gammaproteobacterial sequences and within them, most phylotypes formed a unique cluster related to putative WS/DGAT belonging to marine OM60 clade. In contrast, soils samples contained phylotypes only related to actinomycetes. Among them, phylotypes affiliated with representatives largely or recently reported as oleaginous bacteria, as well as with others considered as possible lipid-accumulating bacteria based on the analysis of their annotated genomes. Our study shows for the first time that the environment could contain a higher variety of ws/dgat than that reported from bacterial isolates. The results of this study highlight the relevance of the environment in a natural process such as the synthesis and accumulation of neutral lipids. Particularly, both marine sediments and soil may serve as a useful source for novel WS/DGAT with biotechnological interest.
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Abstract
Long-chain-length hydrophobic acyl residues play a vital role in a multitude of essential biological structures and processes. They build the inner hydrophobic layers of biological membranes, are converted to intracellular storage compounds, and are used to modify protein properties or function as membrane anchors, to name only a few functions. Acyl thioesters are transferred by acyltransferases or transacylases to a variety of different substrates or are polymerized to lipophilic storage compounds. Lipases represent another important enzyme class dealing with fatty acyl chains; however, they cannot be regarded as acyltransferases in the strict sense. This review provides a detailed survey of the wide spectrum of bacterial acyltransferases and compares different enzyme families in regard to their catalytic mechanisms. On the basis of their studied or assumed mechanisms, most of the acyl-transferring enzymes can be divided into two groups. The majority of enzymes discussed in this review employ a conserved acyltransferase motif with an invariant histidine residue, followed by an acidic amino acid residue, and their catalytic mechanism is characterized by a noncovalent transition state. In contrast to that, lipases rely on completely different mechanism which employs a catalytic triad and functions via the formation of covalent intermediates. This is, for example, similar to the mechanism which has been suggested for polyester synthases. Consequently, although the presented enzyme types neither share homology nor have a common three-dimensional structure, and although they deal with greatly varying molecule structures, this variety is not reflected in their mechanisms, all of which rely on a catalytically active histidine residue.
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Affiliation(s)
- Annika Röttig
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
- Environmental Sciences Department, King Abdulaziz University, Jeddah, Saudi Arabia
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Microbial gutta-percha degradation shares common steps with rubber degradation by Nocardia nova SH22a. Appl Environ Microbiol 2012; 79:1140-9. [PMID: 23220954 DOI: 10.1128/aem.03016-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nocardia nova SH22a, a bacterium capable of degrading gutta-percha (GP) and natural rubber (NR), was used to investigate the GP degradation mechanism and the relations between the GP and NR degradation pathways. For this strain, a protocol of electroporation was systematically optimized, and an efficiency of up to 4.3 × 10(7) CFU per μg of plasmid DNA was achieved. By applying this optimized protocol to N. nova SH22a, a Tn5096-based transposon mutagenesis library of this bacterium was constructed. Among about 12,000 apramycin-resistant transformants, we identified 76 stable mutants defective in GP or NR utilization. Whereas 10 mutants were specifically defective in GP utilization, the growth of the other 66 mutants was affected on both GP and NR. This indicated that the two degradation pathways are quite similar and share many common steps. The larger number of GP-degrading defective mutants could be explained in one of two ways: either (i) the GP pathway is more complex and harbors more specific steps or (ii) the steps for both pathways are almost identical, but in the case of GP degradation there are fewer enzymes involved in each step. The analysis of transposition loci and genetic studies on interesting genes confirmed the crucial role of an α-methylacyl-coenzyme A racemase in the degradation of both GP and NR. We also demonstrated the probable involvement of enzymes participating in oxidoreduction reactions, β-oxidation, and the synthesis of complex cell envelope lipids in the degradation of GP.
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Involvement of two latex-clearing proteins during rubber degradation and insights into the subsequent degradation pathway revealed by the genome sequence of Gordonia polyisoprenivorans strain VH2. Appl Environ Microbiol 2012; 78:2874-87. [PMID: 22327575 DOI: 10.1128/aem.07969-11] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The increasing production of synthetic and natural poly(cis-1,4-isoprene) rubber leads to huge challenges in waste management. Only a few bacteria are known to degrade rubber, and little is known about the mechanism of microbial rubber degradation. The genome of Gordonia polyisoprenivorans strain VH2, which is one of the most effective rubber-degrading bacteria, was sequenced and annotated to elucidate the degradation pathway and other features of this actinomycete. The genome consists of a circular chromosome of 5,669,805 bp and a circular plasmid of 174,494 bp with average GC contents of 67.0% and 65.7%, respectively. It contains 5,110 putative protein-coding sequences, including many candidate genes responsible for rubber degradation and other biotechnically relevant pathways. Furthermore, we detected two homologues of a latex-clearing protein, which is supposed to be a key enzyme in rubber degradation. The deletion of these two genes for the first time revealed clear evidence that latex-clearing protein is essential for the microbial utilization of rubber. Based on the genome sequence, we predict a pathway for the microbial degradation of rubber which is supported by previous and current data on transposon mutagenesis, deletion mutants, applied comparative genomics, and literature search.
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Grossi V, Yakimov MM, Al Ali B, Tapilatu Y, Cuny P, Goutx M, La Cono V, Giuliano L, Tamburini C. Hydrostatic pressure affects membrane and storage lipid compositions of the piezotolerant hydrocarbon-degrading Marinobacter hydrocarbonoclasticus strain #5. Environ Microbiol 2010; 12:2020-33. [DOI: 10.1111/j.1462-2920.2010.02213.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Characterization of indigenous Rhodococcus sp. 602, a strain able to accumulate triacylglycerides from naphthyl compounds under nitrogen-starved conditions. Res Microbiol 2010; 161:198-207. [PMID: 20144706 DOI: 10.1016/j.resmic.2010.01.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 01/04/2010] [Accepted: 01/20/2010] [Indexed: 11/19/2022]
Abstract
An indigenous bacterium (strain 602) isolated in this study from a polluted soil sample collected in Patagonia (Argentina) was investigated in relation to its metabolic responses under unbalanced growth conditions. This strain was identified as Rhodococcus sp. by molecular analyses. Strain 602 showed the ability to degrade a wide range of compounds and to synthesize triacylglycerols under nitrogen-limiting conditions. Cells were also able to accumulate triacylglycerols during cultivation on naphthalene and naphthyl-1-dodecanoate. Triacylglycerols produced by resting cells in the presence of naphthyl-1-dodecanoate contained only short-chain length fatty acids (from C(8) to C(12)), suggesting an initial attack of the substrate by an esterase releasing 1-naphthol and dodecanoic acid, which was subsequently degraded by beta-oxidation. On the other hand, naphthalene seemed to be degraded by a mono-oxygenase yielding 1-naphthol, which was then transformed to 4-hydroxy-1-tetralone and to other possible metabolic intermediates. On the basis of the results obtained, a pathway involved in the metabolism of both aromatic compounds under nitrogen starvation by strain 602 is proposed. The results also demonstrated that Rhodococcus sp. 602 maintains its metabolic activity even in the absence of a nitrogen source. Intracellular triacylglycerols may help cells to maintain their catabolic activities under these growth-restricting conditions.
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Alvarez HM, Steinbüchel A. Physiology, Biochemistry, and Molecular Biology of Triacylglycerol Accumulation by Rhodococcus. BIOLOGY OF RHODOCOCCUS 2010. [DOI: 10.1007/978-3-642-12937-7_10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Hernández MA, Mohn WW, Martínez E, Rost E, Alvarez AF, Alvarez HM. Biosynthesis of storage compounds by Rhodococcus jostii RHA1 and global identification of genes involved in their metabolism. BMC Genomics 2008; 9:600. [PMID: 19077282 PMCID: PMC2667194 DOI: 10.1186/1471-2164-9-600] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 12/12/2008] [Indexed: 11/13/2022] Open
Abstract
Background Members of the genus Rhodococcus are frequently found in soil and other natural environments and are highly resistant to stresses common in those environments. The accumulation of storage compounds permits cells to survive and metabolically adapt during fluctuating environmental conditions. The purpose of this study was to perform a genome-wide bioinformatic analysis of key genes encoding metabolism of diverse storage compounds by Rhodococcus jostii RHA1 and to examine its ability to synthesize and accumulate triacylglycerols (TAG), wax esters, polyhydroxyalkanoates (PHA), glycogen and polyphosphate (PolyP). Results We identified in the RHA1 genome: 14 genes encoding putative wax ester synthase/acyl-CoA:diacylglycerol acyltransferase enzymes (WS/DGATs) likely involved in TAG and wax esters biosynthesis; a total of 54 genes coding for putative lipase/esterase enzymes possibly involved in TAG and wax ester degradation; 3 sets of genes encoding PHA synthases and PHA depolymerases; 6 genes encoding key enzymes for glycogen metabolism, one gene coding for a putative polyphosphate kinase and 3 putative exopolyphosphatase genes. Where possible, key amino acid residues in the above proteins (generally in active sites, effectors binding sites or substrate binding sites) were identified in order to support gene identification. RHA1 cells grown under N-limiting conditions, accumulated TAG as the main storage compounds plus wax esters, PHA (with 3-hydroxybutyrate and 3-hydroxyvalerate monomers), glycogen and PolyP. Rhodococcus members were previously known to accumulate TAG, wax esters, PHAs and polyP, but this is the first report of glycogen accumulation in this genus. Conclusion RHA1 possess key genes to accumulate diverse storage compounds. Under nitrogen-limiting conditions lipids are the principal storage compounds. An extensive capacity to synthesize and metabolize storage compounds appears to contribute versatility to RHA1 in its responses to environmental stresses.
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Affiliation(s)
- Martín A Hernández
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales, Universidad Nacional de Patagonia San Juan Bosco, Km 4-Ciudad Universitaria, 9000 Comodoro Rivadavia, Chubut, Argentina.
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