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Lequan Q, Yanan F, Xianda Z, Mengyuan B, Chenyu L, Shijin W. Mechanisms and high-value applications of phthalate isomers degradation pathways in bacteria. World J Microbiol Biotechnol 2024; 40:247. [PMID: 38904858 DOI: 10.1007/s11274-024-04060-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 06/18/2024] [Indexed: 06/22/2024]
Abstract
Phthalate isomers are key intermediates in the biodegradation of pollutants including waste polyethylene terephthalate (PET) plastics and plasticizers. So far, an increasing number of phthalate isomer-degrading strains have been isolated, and their degradation pathways show significant diversity. In this paper, we comprehensively review the current status of research on the degrading bacteria, degradation characteristics, aerobic and anaerobic degradation pathways, and degradation genes (clusters) of phthalate isomers, and discuss the current shortcomings and challenges. Moreover, the degradation process of phthalate isomers produces many important aromatic precursor molecules, which can be used to produce higher-value derivative chemicals, and the modification of their degradation pathways holds good prospects. Therefore, this review also highlights the current progress made in modifying the phthalate isomer degradation pathway and explores its potential for high-value applications.
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Affiliation(s)
- Qiu Lequan
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China.
| | - Fu Yanan
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Zhou Xianda
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Bao Mengyuan
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Li Chenyu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Wu Shijin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China.
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2
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Mutanda I, Sun J, Jiang J, Zhu D. Bacterial membrane transporter systems for aromatic compounds: Regulation, engineering, and biotechnological applications. Biotechnol Adv 2022; 59:107952. [PMID: 35398204 DOI: 10.1016/j.biotechadv.2022.107952] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/20/2022] [Accepted: 04/02/2022] [Indexed: 12/13/2022]
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3
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Hu R, Zhao H, Xu X, Wang Z, Yu K, Shu L, Yan Q, Wu B, Mo C, He Z, Wang C. Bacteria-driven phthalic acid ester biodegradation: Current status and emerging opportunities. ENVIRONMENT INTERNATIONAL 2021; 154:106560. [PMID: 33866059 DOI: 10.1016/j.envint.2021.106560] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/15/2021] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
The extensive use of phthalic acid esters (PAEs) has led to their widespread distribution across various environments. As PAEs pose significant threats to human health, it is urgent to develop efficient strategies to eliminate them from environments. Bacteria-driven PAE biodegradation has been considered as an inexpensive yet effective strategy to restore the contaminated environments. Despite great advances in bacterial culturing and sequencing, the inherent complexity of indigenous microbial community hinders us to mechanistically understand in situ PAE biodegradation and efficiently harness the degrading power of bacteria. The synthetic microbial ecology provides us a simple and controllable model system to address this problem. In this review, we focus on the current progress of PAE biodegradation mediated by bacterial isolates and indigenous bacterial communities, and discuss the prospective of synthetic PAE-degrading bacterial communities in PAE biodegradation research. It is anticipated that the theories and approaches of synthetic microbial ecology will revolutionize the study of bacteria-driven PAE biodegradation and provide novel insights for developing effective bioremediation solutions.
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Affiliation(s)
- Ruiwen Hu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Haiming Zhao
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Xihui Xu
- Department of Microbiology, Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhigang Wang
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar 161006, China
| | - Ke Yu
- School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Longfei Shu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Qingyun Yan
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Bo Wu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Cehui Mo
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China; College of Agronomy, Hunan Agricultural University, Changsha 410128, China
| | - Cheng Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China.
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DdvK, a Novel Major Facilitator Superfamily Transporter Essential for 5,5'-Dehydrodivanillate Uptake by Sphingobium sp. Strain SYK-6. Appl Environ Microbiol 2018; 84:AEM.01314-18. [PMID: 30120118 DOI: 10.1128/aem.01314-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/02/2018] [Indexed: 12/28/2022] Open
Abstract
The microbial conversion of lignin-derived aromatics is a promising strategy for the industrial utilization of this large biomass resource. However, efficient application requires an elucidation of the relevant transport and catabolic pathways. In Sphingobium sp. strain SYK-6, most of the enzyme genes involved in 5,5'-dehydrodivanillate (DDVA) catabolism have been characterized, but the transporter has not yet been identified. Here, we identified SLG_07710 (ddvK) and SLG_07780 (ddvR), genes encoding a putative major facilitator superfamily (MFS) transporter and MarR-type transcriptional regulator, respectively. A ddvK mutant of SYK-6 completely lost the capacity to grow on and convert DDVA. DdvR repressed the expression of the DDVA O-demethylase oxygenase component gene (ligXa), while DDVA acted as the gene inducer. A DDVA uptake assay was developed by employing this DdvR-controlled ligXa transcriptional regulatory system. A Sphingobium japonicum UT26S transformant expressing ddvK acquired DDVA uptake capacity, indicating that ddvK encodes the DDVA transporter. DdvK, probably requiring the proton motive force, was suggested to be a novel MFS transporter on the basis of the amino acid sequence similarity. Subsequently, we evaluated the effects of ddvK overexpression on the production of the DDVA metabolite 2-pyrone-4,6-dicarboxylate (PDC), a building block of functional polymers. A SYK-6 mutant of the PDC hydrolase gene (ligI) cultured in DDVA accumulated PDC via 5-carboxyvanillate and grew by utilizing 4-carboxy-2-hydroxypenta-2,4-dienoate. The introduction of a ddvK-expression plasmid into a ligI mutant increased the growth rate in DDVA and the amounts of DDVA converted and PDC produced after 48 h by 1.35- and 1.34-fold, respectively. These results indicate that enhanced transporter gene expression can improve metabolite production from lignin derivatives.IMPORTANCE The bioengineering of bacteria to selectively transport and metabolize natural substrates into specific metabolites is a valuable strategy for industrial-scale chemical production. The uptake of many substrates into cells requires specific transport systems, and so the identification and characterization of transporter genes are essential for industrial applications. A number of bacterial major facilitator superfamily transporters of aromatic acids have been identified and characterized, but many transporters of lignin-derived aromatic acids remain unidentified. The efficient conversion of lignin, an abundant but unutilized aromatic biomass resource, to value-added metabolites using microbial catabolism requires the characterization of transporters for lignin-derived aromatics. In this study, we identified the transporter gene responsible for the uptake of 5,5'-dehydrodivanillate, a lignin-derived biphenyl compound, in Sphingobium sp. strain SYK-6. In addition to characterizing its function, we applied this transporter gene to the production of a value-added metabolite from 5,5'-dehydrodivanillate.
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Singleton DR, Lee J, Dickey AN, Stroud A, Scholl EH, Wright FA, Aitken MD. Polyphasic characterization of four soil-derived phenanthrene-degrading Acidovorax strains and proposal of Acidovorax carolinensis sp. nov. Syst Appl Microbiol 2018; 41:460-472. [PMID: 29937052 DOI: 10.1016/j.syapm.2018.06.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/30/2018] [Accepted: 06/01/2018] [Indexed: 10/14/2022]
Abstract
Four bacterial strains identified as members of the Acidovorax genus were isolated from two geographically distinct but similarly contaminated soils in North Carolina, USA, characterized, and their genomes sequenced. Their 16S rRNA genes were highly similar to those previously recovered during stable-isotope probing (SIP) of one of the soils with the polycyclic aromatic hydrocarbon (PAH) phenanthrene. Heterotrophic growth of all strains occurred with a number of organic acids, as well as phenanthrene, but no other tested PAHs. Optimal growth occurred aerobically under mesophilic temperature, neutral pH, and low salinity conditions. Predominant fatty acids were C16:1ω7c/C16:1ω6c, C16:0, and C18:1ω7c, and were consistent with the genus. Genomic G+C contents ranged from 63.6 to 64.2%. A combination of whole genome comparisons and physiological analyses indicated that these four strains likely represent a single species within the Acidovorax genus. Chromosomal genes for phenanthrene degradation to phthalate were nearly identical to highly conserved regions in phenanthrene-degrading Delftia, Burkholderia, Alcaligenes, and Massilia species in regions flanked by transposable or extrachromosomal elements. The lower degradation pathway for phenanthrene metabolism was inferred by comparisons to described genes and proteins. The novel species Acidovorax carolinensis sp. nov. is proposed, comprising the four strains described in this study with strain NA3T as the type strain (=LMG 30136, =DSM 105008).
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Affiliation(s)
- David R Singleton
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7431, USA.
| | - Janice Lee
- Department of Biology, University of North Carolina,Chapel Hill, NC, 27599-3280, USA
| | - Allison N Dickey
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, USA
| | - Aaron Stroud
- Department of Biology, University of North Carolina,Chapel Hill, NC, 27599-3280, USA
| | - Elizabeth H Scholl
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, USA
| | - Fred A Wright
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, USA
| | - Michael D Aitken
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7431, USA
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6
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Hegedüs B, Kós PB, Bende G, Bounedjoum N, Maróti G, Laczi K, Szuhaj M, Perei K, Rákhely G. Starvation- and xenobiotic-related transcriptomic responses of the sulfanilic acid-degrading bacterium, Novosphingobium resinovorum SA1. Appl Microbiol Biotechnol 2017; 102:305-318. [PMID: 29051988 DOI: 10.1007/s00253-017-8553-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 09/19/2017] [Accepted: 09/26/2017] [Indexed: 10/18/2022]
Abstract
Novosphingobium resinovorum SA1 was the first single isolate capable of degrading sulfanilic acid, a widely used representative of sulfonated aromatic compounds. The genome of the strain was recently sequenced, and here, we present whole-cell transcriptome analyses of cells exposed to sulfanilic acid as compared to cells grown on glucose. The comparison of the transcript profiles suggested that the primary impact of sulfanilic acid on the cell transcriptome was a starvation-like effect. The genes of the peripheral, central, and common pathways of sulfanilic acid biodegradation had distinct transcript profiles. The peripheral genes located on a plasmid had very high basal expressions which were hardly upregulated by sulfanilic acid. The genomic context and the codon usage preference of these genes suggested that they were acquired by horizontal gene transfer. The genes of the central pathways were remarkably inducible by sulfanilic acid indicating the presence of a substrate-specific regulatory system in the cells. Surprisingly, the genes of the common part of the metabolic pathway had low and sulfanilic acid-independent transcript levels. The approach applied resulted in the identification of the genes of proteins involved in auxiliary processes such as electron transfer, substrate and iron transports, sulfite oxidases, and sulfite transporters. The whole transcriptome analysis revealed that the cells exposed to xenobiotics had multiple responses including general starvation-like, substrate-specific, and substrate-related effects. From the results, we propose that the genes of the peripheral, central, and common parts of the pathway have been evolved independently.
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Affiliation(s)
- Botond Hegedüs
- Department of Biotechnology, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary.,Institute of Biophysics, Biological Research Center, Temesvári krt. 62, Szeged, 6726, Hungary
| | - Péter B Kós
- Department of Biotechnology, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary.,Institute of Plant Biology, Biological Research Center, Temesvári krt. 62, Szeged, 6726, Hungary
| | - Gábor Bende
- Department of Biotechnology, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary.,Institute of Biophysics, Biological Research Center, Temesvári krt. 62, Szeged, 6726, Hungary
| | - Naila Bounedjoum
- Department of Biotechnology, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary
| | - Gergely Maróti
- Seqomics Ltd, Mórahalom, Vállalkozók útja 7, Mórahalom, 6782, Hungary
| | - Krisztián Laczi
- Department of Biotechnology, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary
| | - Márk Szuhaj
- Department of Biotechnology, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary
| | - Katalin Perei
- Department of Biotechnology, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary
| | - Gábor Rákhely
- Department of Biotechnology, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary. .,Institute of Biophysics, Biological Research Center, Temesvári krt. 62, Szeged, 6726, Hungary. .,Institute of Environmental and Technological Sciences, Közép fasor 52, Szeged, 6726, Hungary.
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7
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Cillingová A, Zeman I, Tóth R, Neboháčová M, Dunčková I, Hölcová M, Jakúbková M, Gérecová G, Pryszcz LP, Tomáška Ľ, Gabaldón T, Gácser A, Nosek J. Eukaryotic transporters for hydroxyderivatives of benzoic acid. Sci Rep 2017; 7:8998. [PMID: 28827635 PMCID: PMC5566891 DOI: 10.1038/s41598-017-09408-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/24/2017] [Indexed: 11/09/2022] Open
Abstract
Several yeast species catabolize hydroxyderivatives of benzoic acid. However, the nature of carriers responsible for transport of these compounds across the plasma membrane is currently unknown. In this study, we analyzed a family of genes coding for permeases belonging to the major facilitator superfamily (MFS) in the pathogenic yeast Candida parapsilosis. Our results revealed that these transporters are functionally equivalent to bacterial aromatic acid: H+ symporters (AAHS) such as GenK, MhbT and PcaK. We demonstrate that the genes HBT1 and HBT2 encoding putative transporters are highly upregulated in C. parapsilosis cells assimilating hydroxybenzoate substrates and the corresponding proteins reside in the plasma membrane. Phenotypic analyses of knockout mutants and hydroxybenzoate uptake assays provide compelling evidence that the permeases Hbt1 and Hbt2 transport the substrates that are metabolized via the gentisate (3-hydroxybenzoate, gentisate) and 3-oxoadipate pathway (4-hydroxybenzoate, 2,4-dihydroxybenzoate and protocatechuate), respectively. Our data support the hypothesis that the carriers belong to the AAHS family of MFS transporters. Phylogenetic analyses revealed that the orthologs of Hbt permeases are widespread in the subphylum Pezizomycotina, but have a sparse distribution among Saccharomycotina lineages. Moreover, these analyses shed additional light on the evolution of biochemical pathways involved in the catabolic degradation of hydroxyaromatic compounds.
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Affiliation(s)
- Andrea Cillingová
- Departments of Biochemistry and Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Igor Zeman
- Departments of Biochemistry and Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Renáta Tóth
- Department of Microbiology, University of Szeged, Szeged, Közép fasor 52, H-6726, Szeged, Hungary
| | - Martina Neboháčová
- Departments of Biochemistry and Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Ivana Dunčková
- Departments of Biochemistry and Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Mária Hölcová
- Departments of Biochemistry and Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Michaela Jakúbková
- Departments of Biochemistry and Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Gabriela Gérecová
- Departments of Biochemistry and Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, 842 15, Bratislava, Slovak Republic.,Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Dr. Bohr Gasse 9, 1030, Vienna, Austria
| | - Leszek P Pryszcz
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation, Doctor Aiguader 88, 08003, Barcelona, Spain.,International Institute of Molecular and Cell Biology in Warsaw, 4 Trojdena Street, 02-109, Warsaw, Poland
| | - Ľubomír Tomáška
- Departments of Biochemistry and Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation, Doctor Aiguader 88, 08003, Barcelona, Spain.,Departament de Ciències Experimentals I de la Salut, Universitat Pompeu Fabra, 08003, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats, Pg. Lluís Companys 23, 08010, Barcelona, Spain
| | - Attila Gácser
- Department of Microbiology, University of Szeged, Szeged, Közép fasor 52, H-6726, Szeged, Hungary
| | - Jozef Nosek
- Departments of Biochemistry and Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, 842 15, Bratislava, Slovak Republic.
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Kumar V, Sharma N, Maitra SS. Comparative study on the degradation of dibutyl phthalate by two newly isolated Pseudomonas sp. V21b and Comamonas sp. 51F. ACTA ACUST UNITED AC 2017; 15:1-10. [PMID: 28580302 PMCID: PMC5447571 DOI: 10.1016/j.btre.2017.04.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/18/2017] [Accepted: 04/18/2017] [Indexed: 11/20/2022]
Abstract
Comparative degradation of DBP by Pseudomonas sp. V21b and Comamonas sp. 51F. Degradation in MSM and contaminated samples. Kinetics of DBP degradation. Stoichiometry of DBP degradation and biomass formation. Phthalate esters genes identification.
Dibutyl phthalate is (DBP) the top priority toxicant responsible for carcinogenicity, teratogenicity and endocrine disruption. This study demonstrates the DBP degradation capability of the two newly isolated bacteria from municipal solid waste leachate samples. The isolated bacteria were designated as Pseudomonas sp. V21b and Comamonas sp. 51F after scanning electron microscopy, transmission electron microscopy, Gram-staining, antibiotic sensitivity tests, biochemical characterization, 16S-rRNA gene identification and phylogenetic studies. They were able to grow on DBP, benzyl butyl phthalate, monobutyl phthalate, diisodecyl phthalate, dioctyl phthalate, and protocatechuate. It was observed that Pseudomonas sp. V21b was more efficient in DBP degradation when compared with Comamonas sp. 51F. It degraded 57% and 76% of the initial DBP in minimal salt medium and in DBP contaminated samples respectively. Kinetics for the effects of DBP concentration on Pseudomonas sp. V21b and Comamonas sp. 51F growth was also evaluated. Stoichiometry for DBP degradation and biomass formation were compared for both the isolates. Two major metabolites diethyl phthalate and monobutyl phthalates were identified using GC–MS in the extracts. Key genes were amplified from the genomes of Pseudomonas sp. V21b and Comamonas sp. 51F. DBP degradation pathway was also proposed.
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Affiliation(s)
- Vinay Kumar
- School of Biotechnology, Jawaharlal Nehru University, Lab no. 117, New Delhi, 110067, India
| | - Neha Sharma
- Arbro Pharmaceuticals Pvt Ltd., New Delhi, 110015, India
| | - S S Maitra
- School of Biotechnology, Jawaharlal Nehru University, Lab no. 117, New Delhi, 110067, India
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Kumar V, Maitra SS. Biodegradation of endocrine disruptor dibutyl phthalate (DBP) by a newly isolated Methylobacillus sp. V29b and the DBP degradation pathway. 3 Biotech 2016; 6:200. [PMID: 28330272 PMCID: PMC5031561 DOI: 10.1007/s13205-016-0524-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 09/14/2016] [Indexed: 11/24/2022] Open
Abstract
Bacteria of the genus Methylobacillus are methanotrophs, a metabolic feature that is widespread in the phylum Proteobacteria. The study demonstrates the isolation and characterization of a newly isolated Methylobacillus sp. V29b. which grows on methanol, protocatechuate, monobutyl phthalate, dibutyl phthalate, diethyl phthalate, benzyl butyl phthalate, dioctyl phthalate and diisodecyl phthalate. Methylobacillus sp. V29b was characterized with scanning electron microscopy, transmission electron microscopy, Gram staining, antibiotics sensitivity tests and biochemical characterization. It degrades 70 % of the initial DBP in minimal salt medium and 65 % of the initial DBP in samples contaminated with DBP. DBP biodegradation kinetics was explained by the Monod growth inhibition model. Values for maximum specific growth rate (µmax) and half-velocity constant (Ks) are 0.07 h−1 and 998.2 mg/l, respectively. Stoichiometry for DBP degradation was calculated for Methylobacillus sp. V29b. Four metabolic intermediates, dibutyl phthalate (DBP), monobutyl phthalate, phthalic acid and pyrocatechol, were identified. Based on the metabolic intermediates identified, a chemical pathway for DBP degradation was proposed. Six genes for phthalic acid degradation were identified from the genome of Methylobacillus sp. V29b.
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Affiliation(s)
- Vinay Kumar
- Lab No. 117, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - S S Maitra
- Lab No. 117, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
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10
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Benjamin S, Pradeep S, Josh MS, Kumar S, Masai E. A monograph on the remediation of hazardous phthalates. JOURNAL OF HAZARDOUS MATERIALS 2015; 298:58-72. [PMID: 26004054 DOI: 10.1016/j.jhazmat.2015.05.004] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 05/02/2015] [Accepted: 05/04/2015] [Indexed: 05/25/2023]
Abstract
Phthalates or phthalic acid esters are a group of xenobiotic and hazardous compounds blended in plastics to enhance their plasticity and versatility. Enormous quantities of phthalates are produced globally for the production of plastic goods, whose disposal and leaching out into the surroundings cause serious concerns to the environment, biota and human health. Though in silico computational, in vitro mechanistic, pre-clinical animal and clinical human studies showed endocrine disruption, hepatotoxic, teratogenic and carcinogenic properties, usage of phthalates continues due to their cuteness, attractive chemical properties, low production cost and lack of suitable alternatives. Studies revealed that microbes isolated from phthalate-contaminated environmental niches efficiently bioremediate various phthalates. Based upon this background, this review addresses the enumeration of major phthalates used in industry, routes of environmental contamination, evidences for health hazards, routes for in situ and ex situ microbial degradation, bacterial pathways involved in the degradation, major enzymes involved in the degradation process, half-lives of phthalates in environments, etc. Briefly, this handy module would enable the readers, environmentalists and policy makers to understand the impact of phthalates on the environment and the biota, coupled with the concerted microbial efforts to alleviate the burden of ever increasing load posed by phthalates.
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Affiliation(s)
- Sailas Benjamin
- Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala 673 635, India.
| | - Selvanesan Pradeep
- Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala 673 635, India
| | - Moolakkariyil Sarath Josh
- Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala 673 635, India
| | - Sunil Kumar
- Solid and Hazardous Waste Management Division, CSIR-NEERI Nehru Marg, Nagpur 440 020, India
| | - Eiji Masai
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2137, Japan
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11
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Novel tripartite aromatic acid transporter essential for terephthalate uptake in Comamonas sp. strain E6. Appl Environ Microbiol 2013; 79:6148-55. [PMID: 23913423 DOI: 10.1128/aem.01600-13] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It has been suggested that a novel type of aromatic acid transporter, which is similar to the tripartite tricarboxylate transporter (TTT), is involved in terephthalate (TPA) uptake by Comamonas sp. strain E6. This suggestion was based on the presence of the putative TPA-binding protein gene, tphC, in the TPA catabolic operon. The tphC gene is essential for growth on TPA and is similar to the genes encoding TTT-like substrate-binding proteins. Here we identified two sets of E6 genes, tctBA and tpiBA, which encode TTT-like cytoplasmic transmembrane proteins. Disruption of tctA showed no influence on TPA uptake but resulted in a complete loss of the uptake of citrate. This loss suggests that tctA is involved in citrate uptake. On the other hand, disruption of tpiA or tpiB demonstrated that both genes are essential for TPA uptake. Only when both tphC and tpiBA were introduced with the TPA catabolic genes into cells of a non-TPA-degrading Pseudomonas strain did the resting cells of the transformant acquire the ability to convert TPA. From all these results, it was concluded that the TPA uptake system consists of the TpiA-TpiB membrane components and TPA-binding TphC. Interestingly, not only was the tpiA mutant of E6 unable to grow on TPA or isophthalate, it also showed significant growth delays on o-phthalate and protocatechuate. These results suggested that the TpiA-TpiB membrane components are able to interact with multiple substrate-binding proteins. The tpiBA genes were constitutively transcribed as a single operon in E6 cells, whereas the transcription of tphC was positively regulated by TphR. TPA uptake by E6 cells was completely inhibited by a protonophore, carbonyl cyanide m-chlorophenyl hydrazone, indicating that the TPA uptake system requires a proton motive force.
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Involvement of a novel ABC transporter and monoalkyl phthalate ester hydrolase in phthalate ester catabolism by Rhodococcus jostii RHA1. Appl Environ Microbiol 2009; 76:1516-23. [PMID: 20038686 DOI: 10.1128/aem.02621-09] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phthalate esters (PEs) are important environmental pollutants. While the biodegradation of the parent compound, phthalate (PTH), is well characterized, the biodegradation of PEs is not well understood. In particular, prior to this study, genes involved in the uptake and hydrolysis of these compounds were not conclusively identified. We found that Rhodococcus jostii RHA1 could grow on a variety of monoalkyl PEs, including methyl, butyl, hexyl, and 2-ethylhexyl PTHs. Strain RHA1 could not grow on most dialkyl PEs, but suspensions of cells grown on PTH transformed dimethyl, diethyl, dipropyl, dibutyl, dihexyl and di-(2-ethylhexyl) PTHs. The major products of these dialkyl PEs were PTH and the corresponding monoalkyl PEs, and minor products resulted from the shortening of the alkyl side chains. RHA1 exhibited an inducible, ATP-dependent uptake system for PTH with a K(m) of 22 microM. The deletion and complementation of the patB gene demonstrated that the ATP-binding cassette (ABC) transporter encoded by patDABC is required for the uptake of PTH and monoalkyl PEs by RHA1. The hydrolase encoded by patE of RHA1 was expressed in Escherichia coli. PatE specifically hydrolyzed monoalkyl PEs to PTH but did not transform dialkyl PEs or other aromatic esters. This investigation of RHA1 elucidates key processes that are consistent with the environmental fate of PEs.
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3-Chlorobenzoate is taken up by a chromosomally encoded transport system in Cupriavidus necator JMP134. Microbiology (Reading) 2009; 155:2757-2765. [DOI: 10.1099/mic.0.029207-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cupriavidus necator JMP134(pJP4) is able to grow on 3-chlorobenzoate (3-CB), a model chloroaromatic pollutant. Catabolism of 3-CB is achieved via the expression of the chromosomally encoded benABCD genes and the tfd genes from plasmid pJP4. Since passive diffusion of benzoic acid derivatives at physiological pH is negligible, the uptake of this compound should be facilitated by a transport system. However, no transporter has so far been described to perform this function, and identification of chloroaromatic compound transporters has been limited. In this work, uptake experiments using 3-[ring-UL-14C]CB showed an inducible transport system in strain JMP134, whose expression is activated by 3-CB and benzoate. A similar level of 3-CB uptake was found for a mutant strain of JMP134, defective in chlorobenzoate degradation, indicating that metabolic drag is not an important component of the measured uptake rate. Competitive inhibitor assays showed that uptake of 3-CB was inhibited by benzoate and, to a lesser degree, by 3-CB and 3,5-dichlorobenzoate, but not by any of 12 other substituted benzoates tested. The expression of several gene candidates for this transport function was analysed by RT-PCR, including both permease-type and ABC-type ATP-dependent transporters. Induction of a chromosomally encoded putative permease transporter (benP gene) was found specifically in the presence of 3-CB or benzoate. A benP knockout mutant of strain JMP134 displayed an almost complete loss of 3-CB transport activity. This is to our knowledge the first report of a 3-CB transporter.
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Deveryshetty J, Phale PS. Biodegradation of phenanthrene by Pseudomonas sp. strain PPD: purification and characterization of 1-hydroxy-2-naphthoic acid dioxygenase. MICROBIOLOGY-SGM 2009; 155:3083-3091. [PMID: 19574301 DOI: 10.1099/mic.0.030460-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pseudomonas sp. strain PPD can metabolize phenanthrene as the sole source of carbon and energy via the 'phthalic acid' route. The key enzyme, 1-hydroxy-2-naphthoic acid dioxygenase (1-HNDO, EC 1.13.11.38), was purified to homogeneity using a 3-hydroxy-2-naphthoic acid (3-H2NA)-affinity matrix. The enzyme was a homotetramer with a native molecular mass of 160 kDa and subunit molecular mass of approximately 39 kDa. It required Fe(II) as the cofactor and was specific for 1-hydroxy-2-naphthoic acid (1-H2NA), with K(m) 13.5 microM and V(max) 114 micromol min(-1) mg(-1). 1-HNDO failed to show activity with gentisic acid, salicylic acid and other hydroxynaphthoic acids tested. Interestingly, the enzyme showed substrate inhibition with a K(i) of 116 microM. 1-HNDO was found to be competitively inhibited by 3-H2NA with a K(i) of 24 microM. Based on the pH-dependent spectral changes, the enzyme reaction product was identified as 2-carboxybenzalpyruvic acid. Under anaerobic conditions, the enzyme failed to convert 1-H2NA to 2-carboxybenzalpyruvic acid. Stoichiometric studies showed the incorporation of 1 mol O(2) into the substrate to yield 1 mol product. These results suggest that 1-HNDO from Pseudomonas sp. strain PPD is an extradiol-type ring-cleaving dioxygenase.
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Affiliation(s)
- Jaigeeth Deveryshetty
- Biotechnology Group, Department of Biosciences and Bioengineering, Indian Institute of Technology - Bombay, Powai, Mumbai 400 076, India
| | - Prashant S Phale
- Biotechnology Group, Department of Biosciences and Bioengineering, Indian Institute of Technology - Bombay, Powai, Mumbai 400 076, India
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Involvement of two transport systems and a specific porin in the uptake of phthalate by Burkholderia spp. J Bacteriol 2009; 191:4671-3. [PMID: 19429613 DOI: 10.1128/jb.00377-09] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia spp. that degrade phthalate have an ABC transporter-type phthalate transport system (OphFGH) and a specific porin (OphP) in addition to a permease-type phthalate transporter (OphD). OphFGH has a lower K(m) and higher V(max) than OphD, which affects how the bacteria grow. OphP is involved in both mechanisms of transport.
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Wang Y, Yin B, Hong Y, Yan Y, Gu JD. Degradation of dimethyl carboxylic phthalate ester by Burkholderia cepacia DA2 isolated from marine sediment of South China Sea. ECOTOXICOLOGY (LONDON, ENGLAND) 2008; 17:845-852. [PMID: 18651216 DOI: 10.1007/s10646-008-0247-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Accepted: 07/09/2008] [Indexed: 05/26/2023]
Abstract
Burkholderia cepacia DA2, isolated from marine sediment of the South China Sea, is capable of utilizing dimethyl phthalate (DMP) as the sole source of carbon and energy. During the transformation of DMP in batch culture, its corresponding degradation intermediates were identified as monomethyl phthalate (MMP) and phthalate acid (PA) sequentially over the time of incubation. The biodegradation biochemical pathway of DMP was DMP to MMP and then to PA before mineralization. Degradation of DMP by B. cepacia DA2 was also dependent upon DMP-induction, and the initial concentrations of DMP affected the degradation rate. Degradation kinetics fit well with the modified Gompertz model. The optimum pH and salinity was 6.0 and < 5 per thousand, respectively, for DMP degradation by B. cepacia DA2. This study showed that the indigenous microorganisms of the deep-ocean sediments are capable of DMP degradation completely.
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Affiliation(s)
- Yali Wang
- Key Laboratory of Tropical Marine Environment Dynamics (LED), South China Sea Institute of Oceanography, Chinese Academy of Sciences, 164 Xingang Road West, Guangzhou 510301, People's Republic of China
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Vamsee-Krishna C, Phale PS. Bacterial degradation of phthalate isomers and their esters. Indian J Microbiol 2008; 48:19-34. [PMID: 23100697 DOI: 10.1007/s12088-008-0003-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 10/03/2007] [Accepted: 10/19/2007] [Indexed: 10/22/2022] Open
Abstract
Phthalate isomers and their esters are used heavily in various industries. Excess use and leaching from the product pose them as major pollutants. These chemicals are toxic, teratogenic, mutagenic and carcinogenic in nature. Various aspects like toxicity, diversity in the aerobic bacterial degradation, enzymes and genetic organization of the metabolic pathways from various bacterial strains are reviewed here. Degradation of these esters proceeds by the action of esterases to form phthalate isomers, which are converted to dihydroxylated intermediates by specific and inducible phthalate isomer dioxygenases. Metabolic pathways of phthalate isomers converge at 3,4-dihydroxybenzoic acid, which undergoes either ortho- or meta- ring cleavage and subsequently metabolized to the central carbon pathway intermediates. The genes involved in the degradation are arranged in operons present either on plasmid or chromosome or both, and induced by specific phthalate isomer. Understanding metabolic pathways, diversity and their genetic regulation may help in constructing bacterial strains through genetic engineering approach for effective bioremediation and environmental clean up.
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Affiliation(s)
- C Vamsee-Krishna
- Biotechnology group School of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Powai, Mumbai, 400 076 India
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Singleton DR, Richardson SD, Aitken MD. Effects of enrichment with phthalate on polycyclic aromatic hydrocarbon biodegradation in contaminated soil. Biodegradation 2007; 19:577-87. [PMID: 17990065 DOI: 10.1007/s10532-007-9163-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2007] [Accepted: 10/29/2007] [Indexed: 11/26/2022]
Abstract
The effect of enrichment with phthalate on the biodegradation of polycyclic aromatic hydrocarbons (PAH) was tested with bioreactor-treated and untreated contaminated soil from a former manufactured gas plant (MGP) site. Soil samples that had been treated in a bioreactor and enriched with phthalate mineralized (14)C-labeled phenanthrene and pyrene to a greater extent than unenriched samples over a 22.5-h incubation, but did not stimulate benzo[a]pyrene mineralization. In contrast to the positive effects on (14)C-labeled phenanthrene and pyrene, no significant differences were found in the extent of biodegradation of native PAH when untreated contaminated soil was incubated with and without phthalate amendment. Denaturing-gradient gel electrophoresis (DGGE) profiles of bacterial 16S rRNA genes from unenriched and phthalate-enriched soil samples were substantially different, and clonal sequences matched to prominent DGGE bands revealed that beta-Proteobacteria related to Ralstonia were most highly enriched by phthalate addition. Quantitative real-time PCR analyses confirmed that, of previously determined PAH-degraders in the bioreactor, only Ralstonia-type organisms increased in response to enrichment, accounting for 89% of the additional bacterial 16S rRNA genes resulting from phthalate enrichment. These findings indicate that phthalate amendment of this particular PAH-contaminated soil did not significantly enrich for organisms associated with high molecular weight PAH degradation or have any significant effect on overall degradation of native PAH in the soil.
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Affiliation(s)
- David R Singleton
- Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
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Endo R, Ohtsubo Y, Tsuda M, Nagata Y. Identification and characterization of genes encoding a putative ABC-type transporter essential for utilization of gamma-hexachlorocyclohexane in Sphingobium japonicum UT26. J Bacteriol 2007; 189:3712-20. [PMID: 17369300 PMCID: PMC1913331 DOI: 10.1128/jb.01883-06] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sphingobium japonicum UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH) as its sole source of carbon and energy. In our previous studies, we cloned and characterized genes encoding enzymes for the conversion of gamma-HCH to beta-ketoadipate in UT26. In this study, we analyzed a mutant obtained by transposon mutagenesis and identified and characterized new genes encoding a putative ABC-type transporter essential for the utilization of gamma-HCH in strain UT26. This putative ABC transporter consists of four components, permease, ATPase, periplasmic protein, and lipoprotein, encoded by linK, linL, linM, and linN, respectively. Mutation and complementation analyses indicated that all the linKLMN genes are required, probably as a set, for gamma-HCH utilization in UT26. Furthermore, the mutant cells deficient in this putative ABC transporter showed (i) higher gamma-HCH degradation activity and greater accumulation of the toxic dead-end product 2,5-dichlorophenol (2,5-DCP), (ii) higher sensitivity to 2,5-DCP itself, and (iii) higher permeability of hydrophobic compounds than the wild-type cells. These results strongly suggested that LinKLMN are involved in gamma-HCH utilization by controlling membrane hydrophobicity. This study clearly demonstrated that a cellular factor besides catabolic enzymes and transcriptional regulators is essential for utilization of xenobiotic compounds in bacterial cells.
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Affiliation(s)
- Ryo Endo
- Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
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Chae JC, Zylstra GJ. 4-Chlorobenzoate uptake in Comamonas sp. strain DJ-12 is mediated by a tripartite ATP-independent periplasmic transporter. J Bacteriol 2006; 188:8407-12. [PMID: 17041053 PMCID: PMC1698221 DOI: 10.1128/jb.00880-06] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The fcb gene cluster involved in the hydrolytic dehalogenation of 4-chlorobenzoate is organized in the order fcbB-fcbA-fcbT1-fcbT2-fcbT3-fcbC in Comamonas sp. strain DJ-12. The genes are operonic and inducible with 4-chloro-, 4-iodo-, and 4-bromobenzoate. The fcbT1, fcbT2, and fcbT3 genes encode a transporter in the secondary TRAP (tripartite ATP-independent periplasmic) family. An fcbT1T2T3 knockout mutant shows a much slower growth rate on 4-chlorobenzoate compared to the wild type. 4-Chlorobenzoate is transported into the wild-type strain five times faster than into the fcbT1T2T3 knockout mutant. Transport of 4-chlorobenzoate shows significant inhibition by 4-bromo-, 4-iodo-, and 4-fluorobenzoate and mild inhibition by 3-chlorobenzoate, 2-chlorobenzoate, 4-hydroxybenzoate, 3-hydroxybenzoate, and benzoate. Uptake of 4-chlorobenzoate is significantly inhibited by ionophores which collapse the proton motive force.
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Affiliation(s)
- Jong-Chan Chae
- Biotech Center for Agriculture and the Environment, Rutgers University, New Brunswick, NJ 08901-8520, USA
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Patrauchan MA, Florizone C, Dosanjh M, Mohn WW, Davies J, Eltis LD. Catabolism of benzoate and phthalate in Rhodococcus sp. strain RHA1: redundancies and convergence. J Bacteriol 2005; 187:4050-63. [PMID: 15937168 PMCID: PMC1151724 DOI: 10.1128/jb.187.12.4050-4063.2005] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Genomic and proteomic approaches were used to investigate phthalate and benzoate catabolism in Rhodococcus sp. strain RHA1, a polychlorinated biphenyl-degrading actinomycete. Sequence analyses identified genes involved in the catabolism of benzoate (ben) and phthalate (pad), the uptake of phthalate (pat), and two branches of the beta-ketoadipate pathway (catRABC and pcaJIHGBLFR). The regulatory and structural ben genes are separated by genes encoding a cytochrome P450. The pad and pat genes are contained on a catabolic island that is duplicated on plasmids pRHL1 and pRHL2 and includes predicted terephthalate catabolic genes (tpa). Proteomic analyses demonstrated that the beta-ketoadipate pathway is functionally convergent. Specifically, the pad and pat gene products were only detected in phthalate-grown cells. Similarly, the ben and cat gene products were only detected in benzoate-grown cells. However, pca-encoded enzymes were present under both growth conditions. Activity assays for key enzymes confirmed these results. Disruption of pcaL, which encodes a fusion enzyme, abolished growth on phthalate. In contrast, after a lag phase, growth of the mutant on benzoate was similar to that of the wild type. Proteomic analyses revealed 20 proteins in the mutant that were not detected in wild-type cells during growth on benzoate, including a CatD homolog that apparently compensated for loss of PcaL. Analysis of completed bacterial genomes indicates that the convergent beta-ketoadipate pathway and some aspects of its genetic organization are characteristic of rhodococci and related actinomycetes. In contrast, the high redundancy of catabolic pathways and enzymes appears to be unique to RHA1 and may increase its potential to adapt to new carbon sources.
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Affiliation(s)
- Marianna A Patrauchan
- Department of Microbiology and Immunology, University of British Columbia, #300-6174 University Blvd., Vancouver, BC, V6T 1Z3, Canada
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Yuroff AS, Sabat G, Hickey WJ. Transporter-mediated uptake of 2-chloro- and 2-hydroxybenzoate by Pseudomonas huttiensis strain D1. Appl Environ Microbiol 2004; 69:7401-8. [PMID: 14660391 PMCID: PMC309881 DOI: 10.1128/aem.69.12.7401-7408.2003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the mechanisms of uptake of 2-chlorobenzoate (2-CBa) and 2-hydroxybenzoate (2-HBa) by Pseudomonas huttiensis strain D1. Uptake was monitored by assaying intracellular accumulation of 2-[UL-ring-14C]CBa and 2-[UL-ring-14C]HBa. Uptake of 2-CBa showed substrate saturation kinetics with an apparent Km of 12.7 +/- 2.6 micromoles and a maximum velocity (Vmax) of 9.76 +/- 0.78 nmol min-1 mg of protein-1. Enhanced rates of uptake were induced by growth on 2-CBa and 2-HBa, but not by growth on benzoate or 2,5-di-CBa. Intracellular accumulations of 2-CBa and 2-HBa were 109- and 42-fold greater, respectively, than the extracellular concentrations of these substrates and were indicative of uptake mediated by a transporter rather than driven by substrate catabolism ("metabolic drag"). Results of competitor screening tests indicated that the substrate range of the transporter did not include other o-halobenzoates that serve as growth substrates for strain D1 and for which the metabolism was initiated by the same dioxygenase as 2-CBa and 2-HBa. This suggested that multiple mechanisms for substrate uptake were coupled to the same catabolic enzyme. The preponderance of evidence from tests with metabolic inhibitors and artificial electrochemical gradients suggested that 2-CBa uptake was driven by ATP hydrolysis. If so, the 2-CBa transporter would be the first of the ATP binding cassette type implicated in uptake of haloaromatic acids.
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Affiliation(s)
- A S Yuroff
- Center for Molecular and Environmental Toxicology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Cruz A, Fernandes P, Cabral J, Pinheiro H. Solvent partitioning and whole-cell sitosterol bioconversion activity in aqueous-organic two-phase systems. Enzyme Microb Technol 2004. [DOI: 10.1016/j.enzmictec.2003.11.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ditty JL, Harwood CS. Charged amino acids conserved in the aromatic acid/H+ symporter family of permeases are required for 4-hydroxybenzoate transport by PcaK from Pseudomonas putida. J Bacteriol 2002; 184:1444-8. [PMID: 11844776 PMCID: PMC134867 DOI: 10.1128/jb.184.5.1444-1448.2002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Charged amino acids in the predicted transmembrane portion of PcaK, a permease from Pseudomonas putida that transports 4-hydroxybenzoate (4-HBA), were required for 4-HBA transport, and they were also required for P. putida to have a chemotactic response to 4-HBA. An essential amino acid motif (DGXD) containing aspartate residues is located in the first transmembrane segment of PcaK and is conserved in the aromatic acid/H+ symporter family of the major facilitator superfamily of transporters.
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Affiliation(s)
- Jayna L Ditty
- Department of Microbiology, The University of Iowa, Iowa City, IA 52242, USA
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Abstract
Several 2-substituted benzoates (including 2-trifluoromethyl-, 2-chloro-, 2-bromo-, 2-iodo-, 2-nitro-, 2-methoxy-, and 2-acetyl-benzoates) were converted by phthalate-grown Arthrobacter keyseri (formerly Micrococcus sp.) 12B to the corresponding 2-substituted 3,4-dihydroxybenzoates (protocatechuates). Because these products lack a carboxyl group at the 2 position, they were not substrates for the next enzyme of the phthalate catabolic pathway, 3,4-dihydroxyphthalate 2-decarboxylase, and accumulated. When these incubations were carried out in iron-containing minimal medium, the products formed colored chelates. This chromogenic response was subsequently used to identify recombinant Escherichia coli strains carrying genes encoding the responsible enzymes, phthalate 3,4-dioxygenase and 3,4-dihydroxy-3,4-dihydrophthalate dehydrogenase, from the 130-kbp plasmid pRE1 of strain 12B. Beginning with the initially cloned 8.14-kbp PstI fragment of pRE824 as a probe to identify recombinant plasmids carrying overlapping fragments, a DNA segment of 33.5 kbp was cloned from pRE1 on several plasmids and mapped using restriction endonucleases. From these plasmids, the sequence of 26,274 contiguous bp was determined. Sequenced DNA included several genetic units: tnpR, pcm operon, ptr genes, pehA, norA fragment, and pht operon, encoding a transposon resolvase, catabolism of protocatechuate (3,4-dihydroxybenzoate), a putative ATP-binding cassette transporter, a possible phthalate ester hydrolase, a fragment of a norfloxacin resistance-like transporter, and the conversion of phthalate to protocatechuate, respectively. Activities of the eight enzymes involved in the catabolism of phthalate through protocatechuate to pyruvate and oxaloacetate were demonstrated in cells or cell extracts of recombinant E. coli strains.
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Affiliation(s)
- R W Eaton
- Gulf Ecology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Gulf Breeze, Florida 32561, USA.
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Abstract
The treatment of environmental pollution by microorganisms is a promising technology. Various genetic approaches have been developed and used to optimize the enzymes, metabolic pathways and organisms relevant for biodegradation. New information on the metabolic routes and bottlenecks of degradation is still accumulating, enlarging the available toolbox. With molecular methods allowing the characterization of microbial community structure and activities, the performance of microorganisms under in situ conditions and in concert with the indigenous microflora will become predictable.
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Affiliation(s)
- D H Pieper
- Department of Environmental Biotechnology, Gesellschaft für Biotechnologische Forschung mbH (GBF), Braunschweig, D-38124, Germany.
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