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Hurst R, Brewer DS, Gihawi A, Wain J, Cooper CS. Cancer invasion and anaerobic bacteria: new insights into mechanisms. J Med Microbiol 2024; 73:001817. [PMID: 38535967 PMCID: PMC10995961 DOI: 10.1099/jmm.0.001817] [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: 11/29/2023] [Accepted: 02/27/2024] [Indexed: 04/07/2024] Open
Abstract
There is growing evidence that altered microbiota abundance of a range of specific anaerobic bacteria are associated with cancer, including Peptoniphilus spp., Porphyromonas spp., Fusobacterium spp., Fenollaria spp., Prevotella spp., Sneathia spp., Veillonella spp. and Anaerococcus spp. linked to multiple cancer types. In this review we explore these pathogenic associations. The mechanisms by which bacteria are known or predicted to interact with human cells are reviewed and we present an overview of the interlinked mechanisms and hypotheses of how multiple intracellular anaerobic bacterial pathogens may act together to cause host cell and tissue microenvironment changes associated with carcinogenesis and cancer cell invasion. These include combined effects on changes in cell signalling, DNA damage, cellular metabolism and immune evasion. Strategies for early detection and eradication of anaerobic cancer-associated bacterial pathogens that may prevent cancer progression are proposed.
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Affiliation(s)
- Rachel Hurst
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | - Daniel S. Brewer
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
- Earlham Institute, Norwich Research Park Innovation Centre, Colney Lane, Norwich NR4 7UZ, UK
| | - Abraham Gihawi
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | - John Wain
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
- Quadram Institute Biosciences, Colney Lane, Norwich, Norfolk, NR4 7UQ, UK
| | - Colin S. Cooper
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
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Zhang X, Huang X, Li X, Zhang J, Tang M, Liu X, Wang D, Yang Q, Duan A, Liu J. Performance and mechanisms of citric acid improving biotransformation of waste activated sludge into short-chain fatty acids. BIORESOURCE TECHNOLOGY 2023; 373:128754. [PMID: 36801444 DOI: 10.1016/j.biortech.2023.128754] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
Numerous effective chemical strategies have been explored for short-chain fatty acids (SCFAs) production from waste activated sludge (WAS), but many technologies have been questioned due to the chemical residues. This study proposed a citric acid (CA) treatment strategy for improving SCFAs production from WAS. The optimum SCFAs yield reached 384.4 mg COD/g VSS with 0.08 g CA/g TSS addition. Meanwhile, CA biodegradation occurred and its contribution to the yield of total SCFAs, especially acetic acid, cannot be ignored. Intensive exploration indicated the sludge decomposition, the biodegradability of fermentation substrates, as well as the abundance of fermenting microorganisms were definitely enhanced in the existence of CA. The optimization of SCFAs production techniques based on this study deserved further study. This study comprehensively revealed the performance and mechanisms of CA enhancing biotransformation of WAS into SCFAs and the findings promotes the research of carbon resource recovery from sludge.
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Affiliation(s)
- Xiaodong Zhang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Xiaoding Huang
- College of Resources and Environment, Anqing Normal University, Anhui 246011, PR China; Key Laboratory of Aqueous Environment Protection and Pollution Control of Yangtze River of Anhui Provincial Education Department, Anqing, Anhui 246011, PR China
| | - Xiaoming Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
| | - Jiamin Zhang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Mengge Tang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Xuran Liu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Dongbo Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Qi Yang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Abing Duan
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Junwu Liu
- Hunan Engineering Research Center of Mining Site Pollution Remediation, Changsha 410082, PR China
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Hu J, Jin K, He ZG, Zhang H. Citrate lyase CitE in Mycobacterium tuberculosis contributes to mycobacterial survival under hypoxic conditions. PLoS One 2020; 15:e0230786. [PMID: 32302313 PMCID: PMC7164622 DOI: 10.1371/journal.pone.0230786] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 03/08/2020] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis is the causative agent of tuberculosis and has evolved an ability to survive in hostile host environments. M. tuberculosis is thought to utilize the rTCA cycle to sustain its latent growth during infection, but the enzymatic characteristics and physiological function for the key citrate lyase of the rTCA cycle, MtbCitE, in the important pathogen remain unclear. In this study, we investigated the function of MtbCitE based on its structural properties and sequence comparisons with other bacterial citrate lyase subunits. We showed that several amino acid residues were important for the citrate cleavage activity of MtbCitE. Strikingly, the citrate cleavage activity of MtbCitE was inhibited by ATP, indicating that energy metabolism might couple with the regulation of MtbCitE activity, which differed from other CitEs. More interestingly, deletion of citE from Mycobacterium bovis BCG decreased the mycobacterial survival rate under hypoxic conditions, whereas complementation with citE restored the phenotype to wild-type levels. Consistently, three key rTCA cycle enzymes were positively regulated under hypoxic conditions in mycobacteria. Therefore, we characterized a unique citrate lyase MtbCitE from M. tuberculosis and found that the CitE protein significantly contributed to mycobacterial survival under hypoxic conditions.
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Affiliation(s)
- Jialing Hu
- College of Life Science and Technology, National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Kaixi Jin
- College of Life Science and Technology, National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Zheng-Guo He
- College of Life Science and Technology, National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Hua Zhang
- College of Life Science and Technology, National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- * E-mail:
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Alfán-Guzmán R, Ertan H, Manefield M, Lee M. Isolation and Characterization of Dehalobacter sp. Strain TeCB1 Including Identification of TcbA: A Novel Tetra- and Trichlorobenzene Reductive Dehalogenase. Front Microbiol 2017; 8:558. [PMID: 28421054 PMCID: PMC5379058 DOI: 10.3389/fmicb.2017.00558] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 03/16/2017] [Indexed: 11/13/2022] Open
Abstract
Dehalobacter sp. strain TeCB1 was isolated from groundwater near Sydney, Australia, that is polluted with a range of organochlorines. The isolated strain is able to grow by reductive dechlorination of 1,2,4,5-tetrachlorobenzene to 1,3- and 1,4-dichlorobenzene with 1,2,4-trichlorobenzene being the intermediate daughter product. Transient production of 1,2-dichlorobenzene was detected with subsequent conversion to monochlorobenzene. The dehalogenation capability of strain TeCB1 to respire 23 alternative organochlorines was examined and shown to be limited to the use of 1,2,4,5-tetrachlorobenzene and 1,2,4-trichlorobenzene. Growth on 1,2,4-trichlorobenzene resulted in the production of predominantly 1,3- and 1,4-dichlorobenzene. The inability of strain TeCB1 to grow on 1,2-dichlorobenzene indicated that the production of monochlorobenzene during growth on 1,2,4,5-tetarchlorobezene was cometabolic. The annotated genome of strain TeCB1 contained only one detectable 16S rRNA gene copy and genes for 23 full-length and one truncated Reductive Dehalogenase (RDase) homologs, five unique to strain TeCB1. Identification and functional characterization of the 1,2,4,5-tetrachlorobenzene and 1,2,4-trichlorobenzene RDase (TcbA) was achieved using native-PAGE coupled with liquid chromatography tandem mass spectrometry. Interestingly, TcbA showed higher amino acid identity with tetrachloroethene reductases PceA (95% identity) from Dehalobacter restrictus PER-K23 and Desulfitobacterium hafniense Y51 than with the only other chlorinated benzene reductase [i.e., CbrA (30% identity)] functionally characterized to date.
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Affiliation(s)
- Ricardo Alfán-Guzmán
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, SydneyNSW, Australia
| | - Haluk Ertan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, SydneyNSW, Australia.,Department of Molecular Biology and Genetics, Istanbul UniversityIstanbul, Turkey
| | - Mike Manefield
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, SydneyNSW, Australia
| | - Matthew Lee
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, SydneyNSW, Australia
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5
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Abstract
Environmental citrate or malonate is degraded by a variety of aerobic or anaerobic bacteria. For selected examples, the genes encoding the specific enzymes of the degradation pathway are described together with the encoded proteins and their catalytic mechanisms. Aerobic bacteria degrade citrate readily by the basic enzyme equipment of the cell if a specific transporter for citrate is available. Anaerobic degradation of citrate in Klebsiella pneumoniae requires the so-called substrate activation module to convert citrate into its thioester with the phosphoribosyl dephospho-CoA prosthetic group of citrate lyase. The citryl thioester is subsequently cleaved into oxaloacetate and the acetyl thioester, from which a new citryl thioester is formed as the turnover continues. The degradation of malonate likewise includes a substrate activation module with a phosphoribosyl dephospho-CoA prosthetic group. The machinery gets ready for turnover after forming the acetyl thioester with the prosthetic group. The acetyl residue is then exchanged by a malonyl residue, which is easily decarboxylated with the regeneration of the acetyl thioester. This equipment suffices for aerobic growth on malonate, since ATP is produced via the oxidation of acetate. Anaerobic growth on citrate or malonate, however, depends on additional enzymes of a so-called energy conservation module. This allows the conversion of decarboxylation energy into an electrochemical gradient of Na+ ions. In citrate-fermenting K. pneumoniae, the Na+ gradient is formed by the oxaloacetate decarboxylase and mainly used to drive the active transport of citrate into the cell. To use this energy source for this purpose is possible, since ATP is generated by substrate phosphorylation in the well-known sequence from pyruvate to acetate. In the malonate-fermenting bacterium Malonomonas rubra, however, no reactions for substrate level phosphorylation are available and the Na+ gradient formed in the malonate decarboxylation reaction must therefore be used as the driving force for ATP synthesis.
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Pal R, Beeby A, Parker D. Analysis of citrate in low-volume seminal fluid samples using a time-gated measurement of europium luminescence. J Pharm Biomed Anal 2011; 56:352-8. [PMID: 21680129 DOI: 10.1016/j.jpba.2011.05.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 04/27/2011] [Accepted: 05/15/2011] [Indexed: 11/28/2022]
Abstract
This work aims to develop and validate a rapid analytical method that enables the measurement of citrate in seminal fluid samples. Samples were obtained from men who were within 9 weeks of a vasectomy operation. Two age ranges were examined, between 40-43 and 50-53 years old, with nearly 100 samples in each case. No patient clinical history was available for this anonymous study, simulating a random screening cohort. The concentration of citrate in 0.5 μL seminal fluid samples was assessed, using a europium emission luminescence method. This involves the ratiometric analysis of two well-separated europium(III) emission bands. Spectral data were obtained using a time-gated spectrometer whose construction and modification is described. Citrate values were confirmed by independent measurements using a citrate lyase enzymatic assay and by 700 MHz ¹H NMR analysis of the seminal fluid. Citrate concentrations were not statistically different between age groups and averaged 35.0(±14.6) mM for the 40-43 group, and 28.2(±12.7) mM for the 50-53 cohort; in each case a polymodal distribution was observed.
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Affiliation(s)
- Robert Pal
- Department of Chemistry, Durham University, South Road, Durham DH13LE, UK.
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7
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Rapid and simple biochemical detection for Salmonella spp. using modified LB broth and the MUCAP test. Food Sci Biotechnol 2011. [DOI: 10.1007/s10068-011-0027-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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8
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Madriz L, Carrero H, Herrera J, Cabrera A, Canudas N, Fernández L. Photocatalytic Activity of Metalloporphyrin–Titanium Mixtures in Microemulsions. Top Catal 2011. [DOI: 10.1007/s11244-011-9640-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Trutnau M, Petzold M, Mehlig L, Eschenhagen M, Geipel K, Müller S, Bley T, Röske I. Using a carbon-based ASM3 EAWAG Bio-P for modelling the enhanced biological phosphorus removal in anaerobic/aerobic activated sludge systems. Bioprocess Biosyst Eng 2010; 34:287-95. [PMID: 20872271 DOI: 10.1007/s00449-010-0470-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 09/10/2010] [Indexed: 11/29/2022]
Abstract
Modelling of activated sludge processes is a commonly used technique to design and optimize wastewater treatment processes. Since wastewater and activated sludge is characterized by chemical oxygen demand (COD) measurements, units of state variables describing organic matter are expressed as equivalent amounts of COD. However, current procedures for measuring it have several drawbacks, including the production of hazardous wastes, so the utility of other variables for characterizing the organic load in modelling, such as total organic carbon (TOC), warrant re-evaluation. Other advantages of TOC over COD are that it provides matrix-independent analytical results and it can be readily measured online. Proposals for TOC-based models were made in the 1990s, but they seem to have sunk into obscurity. To re-assess the value of TOC for this purpose, we have recalculated the EAWAG module for Bio-P removal coupled to the Activated Sludge Model No. 3 on a TOC basis, and tested it against data acquired in batch experiments with four single carbon sources (acetate, glucose, citrate and casein). The batch test-based calibrations showed a good match with experimental data, following modifications of the model to account for the anaerobic volumes and retention times applied in the tests.
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Affiliation(s)
- Mirko Trutnau
- Institute of Food Technology and Bioprocess Engineering, TU Dresden, Bergstraße 120, 01062 Dresden, Germany.
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10
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Citric acid wastewater as electron donor for biological sulfate reduction. Appl Microbiol Biotechnol 2009; 83:957-63. [PMID: 19399495 PMCID: PMC2699387 DOI: 10.1007/s00253-009-1995-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 03/31/2009] [Accepted: 03/31/2009] [Indexed: 11/04/2022]
Abstract
Citrate-containing wastewater is used as electron donor for sulfate reduction in a biological treatment plant for the removal of sulfate. The pathway of citrate conversion coupled to sulfate reduction and the microorganisms involved were investigated. Citrate was not a direct electron donor for the sulfate-reducing bacteria. Instead, citrate was fermented to mainly acetate and formate. These fermentation products served as electron donors for the sulfate-reducing bacteria. Sulfate reduction activities of the reactor biomass with acetate and formate were sufficiently high to explain the sulfate reduction rates that are required for the process. Two citrate-fermenting bacteria were isolated. Strain R210 was closest related to Trichococcus pasteurii (99.5% ribosomal RNA (rRNA) gene sequence similarity). The closest relative of strain S101 was Veillonella montepellierensis with an rRNA gene sequence similarity of 96.7%. Both strains had a complementary substrate range.
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11
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Anaerobic degradation of citrate under sulfate reducing and methanogenic conditions. Biodegradation 2008; 20:499-510. [DOI: 10.1007/s10532-008-9239-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Accepted: 12/03/2008] [Indexed: 11/25/2022]
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12
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Sierra-Alvarez R, Hollingsworth J, Zhou MS. Removal of copper in an integrated sulfate reducing bioreactor-crystallization reactor system. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:1426-31. [PMID: 17593752 DOI: 10.1021/es062152l] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Removal of copper was investigated using an innovative water treatment system integrating a sulfidogenic bioreactor with a fluidized-bed crystallization reactor containing fine sand to facilitate the recovery of copper as a purified copper-sulfide mineral. The performance of the system was tested using a simulated semiconductor manufacturing wastewater containing high levels of Cu2+ (4-66 mg/L), sulfate, and a mixture of citrate, isopropanol, and polyethylene glycol (Mn 300). Soluble copper removal efficiencies exceeding 99% and effluent copper concentrations averaging 89 micog/L were demonstrated in the two-stage system, with near complete metal removal occurring in the crystallizer. Copper crystals deposited on sand grains were identified as covellite (CuS). The removal of organic constituents did not exceed 70% of the initial chemical oxygen demand due to incomplete degradation of isopropanol and its breakdown product (acetone). Taken as a whole, these results indicate the potential of this novel reactor configuration for the simultaneous removal of heavy metals and organic constituents. The ability of this process to recover heavy metals in a purified form makes it particularly attractive for the treatment of contaminated aqueous streams, including industrial wastewaters and acid mine drainage.
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Affiliation(s)
- Reyes Sierra-Alvarez
- Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson 85721-0011, Arizona, USA.
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Hollingsworth J, Sierra-Alvarez R, Zhou M, Ogden KL, Field JA. Anaerobic biodegradability and methanogenic toxicity of key constituents in copper chemical mechanical planarization effluents of the semiconductor industry. CHEMOSPHERE 2005; 59:1219-28. [PMID: 15857633 DOI: 10.1016/j.chemosphere.2004.11.067] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2004] [Revised: 11/22/2004] [Accepted: 11/25/2004] [Indexed: 05/02/2023]
Abstract
Copper chemical mechanical planarization (CMP) effluents can account for 30-40% of the water discharge in semiconductor manufacturing. CMP effluents contain high concentrations of soluble copper and a complex mixture of organic constituents. The aim of this study is to perform a preliminary assessment of the treatability of CMP effluents in anaerobic sulfidogenic bioreactors inoculated with anaerobic granular sludge by testing individual compounds expected in the CMP effluents. Of all the compounds tested (copper (II), benzotriazoles, polyethylene glycol (M(n) 300), polyethylene glycol (M(n) 860) monooleate, perfluoro-1-octane sulfonate, citric acid, oxalic acid and isopropanol) only copper was found to be inhibitory to methanogenic activity at the concentrations tested. Most of the organic compounds tested were biodegradable with the exception of perfluoro-1-octane sulfonate and benzotriazoles under sulfate reducing conditions and with the exception of the same compounds as well as Triton X-100 under methanogenic conditions. The susceptibility of key components in CMP effluents to anaerobic biodegradation combined with their low microbial inhibition suggest that CMP effluents should be amenable to biological treatment in sulfate reducing bioreactors.
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Affiliation(s)
- Jeremy Hollingsworth
- Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ 85721-0011, USA
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Schneider K, Kästner CN, Meyer M, Wessel M, Dimroth P, Bott M. Identification of a gene cluster in Klebsiella pneumoniae which includes citX, a gene required for biosynthesis of the citrate lyase prosthetic group. J Bacteriol 2002; 184:2439-46. [PMID: 11948157 PMCID: PMC134981 DOI: 10.1128/jb.184.9.2439-2446.2002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The biosynthesis of the 2'-(5"-phosphoribosyl)-3'-dephospho-coenzyme A (CoA) prosthetic group of citrate lyase (EC 4.1.3.6), a key enzyme of citrate fermentation, proceeds via the initial formation of the precursor 2'-(5"-triphosphoribosyl)-3'-dephospho-CoA and subsequent transfer to apo-citrate lyase with removal of pyrophosphate. In Escherichia coli, the two steps are catalyzed by CitG and CitX, respectively, and the corresponding genes are part of the citrate lyase gene cluster, citCDEFXG. In the homologous citCDEFG operon of Klebsiella pneumoniae, citX is missing. A search for K. pneumoniae citX led to the identification of a second genome region involved in citrate fermentation which comprised the citWX genes and the divergent citYZ genes. The citX gene was confirmed to encode holo-citrate lyase synthase, whereas citW was shown to encode a citrate carrier, the third one identified in this species. The citYZ genes were found to encode a two-component system consisting of the sensor kinase CitY and the response regulator CitZ. Remarkably, both proteins showed >or=40% sequence identity to the citrate-sensing CitA-CitB two-component system, which is essential for the induction of the citrate fermentation genes in K. pneumoniae. A citZ insertion mutant was able to grow anaerobically with citrate, indicating that CitZ is not essential for expression of citrate fermentation genes. CitX synthesis was induced to a basal level under anaerobic conditions, independent of citrate, CitB, and CitZ, and to maximal levels during anaerobic growth with citrate as the sole carbon source. Similar to the other citrate fermentation enzymes, CitX synthesis was apparently subject to catabolite repression.
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Affiliation(s)
- Karin Schneider
- Institut für Mikrobiologie, Eidgenössische Technische Hochschule Zürich, CH-8092 Zürich, Switzerland
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Schneider K, Dimroth P, Bott M. Identification of triphosphoribosyl-dephospho-CoA as precursor of the citrate lyase prosthetic group. FEBS Lett 2000; 483:165-8. [PMID: 11042274 DOI: 10.1016/s0014-5793(00)02105-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The gamma-subunit of citrate lyase (EC 4.1.3.6) contains the prosthetic group 2'-(5"-phosphoribosyl)-3'-dephospho-CoA and serves as an acyl carrier protein (ACP). We recently showed that in Escherichia coli the proteins CitG and CitX are essential for holo-ACP synthesis and provided evidence that CitG catalyzes the formation of a prosthetic group precursor from ATP and dephospho-CoA, which is subsequently attached via phosphodiester linkage to apo-ACP by CitX. Here we prove that CitG indeed catalyzes the conversion of ATP and dephospho-CoA to adenine and 2'-(5"-triphosphoribosyl)-3'-dephospho-CoA, the predicted precursor of the prosthetic group. Furthermore, this precursor was transferred by CitX to apo-ACP, yielding holo-ACP. Thus, our proposed mechanism for holo-ACP synthesis could be verified.
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Affiliation(s)
- K Schneider
- Institut für Mikrobiologie, Eidgenössische Technische Hochschule Zürich, Switzerland
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16
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Abstract
Citrate lyase (EC 4.1.3.6) catalyzes the cleavage of citrate to acetate and oxaloacetate and is composed of three subunits (alpha, beta, and gamma). The gamma-subunit serves as an acyl carrier protein (ACP) and contains the prosthetic group 2'-(5' '-phosphoribosyl)-3'-dephospho-CoA, which is attached via a phosphodiester linkage to serine-14 in the enzyme from Klebsiella pneumoniae. In this work, we demonstrate by genetic and biochemical studies with citrate lyase of Escherichia coli and K. pneumoniae that the conversion of apo-ACP into holo-ACP is dependent on the two proteins, CitX (20 kDa) and CitG (33 kDa). In the absence of CitX, only apo-ACP was synthesized in vivo, whereas in the absence of CitG, an adenylylated ACP was produced, with the AMP residue attached to serine-14. The adenylyltransferase activity of CitX could be verified in vitro with purified CitX and apo-ACP plus ATP as substrates. Besides ATP, CTP, GTP, and UTP also served as nucleotidyl donors in vitro, showing that CitX functions as a nucleotidyltransferase. The conversion of apo-ACP into holo-ACP was achieved in vitro by incubation of apo-ACP with CitX, CitG, ATP, and dephospho-CoA. ATP could not be substituted with GTP, CTP, UTP, ADP, or AMP. In the absence of CitG or dephospho-CoA, AMP-ACP was formed. Remarkably, it was not possible to further convert AMP-ACP to holo-ACP by subsequent incubation with CitG and dephospho-CoA. This demonstrates that AMP-ACP is not an intermediate during the conversion of apo- into holo-ACP, but results from a side activity of CitX that becomes effective in the absence of its natural substrate. Our results indicate that holo-ACP formation proceeds as follows. First, a prosthetic group precursor [presumably 2'-(5' '-triphosphoribosyl)-3'-dephospho-CoA] is formed from ATP and dephospho-CoA in a reaction catalyzed by CitG. Second, holo-ACP is formed from apo-ACP and the prosthetic group precursor in a reaction catalyzed by CitX.
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Affiliation(s)
- K Schneider
- Institut für Mikrobiologie, Eidgenössische Technische Hochschule Zürich, Switzerland
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17
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Bekal S, Van Beeumen J, Samyn B, Garmyn D, Henini S, Diviès C, Prévost H. Purification of Leuconostoc mesenteroides citrate lyase and cloning and characterization of the citCDEFG gene cluster. J Bacteriol 1998; 180:647-54. [PMID: 9457870 PMCID: PMC106934 DOI: 10.1128/jb.180.3.647-654.1998] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
A citrate lyase (EC 4.1.3.6) was purified 25-fold from Leuconostoc mesenteroides and was shown to contain three subunits. The first 42 amino acids of the beta subunit were identified, as well as an internal peptide sequence spanning some 20 amino acids into the alpha subunit. Using degenerated primers from these sequences, we amplified a 1.2-kb DNA fragment by PCR from Leuconostoc mesenteroides subsp. cremoris. This fragment was used as a probe for screening a Leuconostoc genomic bank to identify the structural genes. The 2.7-kb gene cluster encoding citrate lyase of L. mesenteroides is organized in three open reading frames, citD, citE, and citF, encoding, respectively, the three citrate lyase subunits gamma (acyl carrier protein [ACP]), beta (citryl-S-ACP lyase; EC 4.1.3.34), and alpha (citrate:acetyl-ACP transferase; EC 2.8.3.10). The gene (citC) encoding the citrate lyase ligase (EC 6.2.1.22) was localized in the region upstream of citD. Protein comparisons show similarities with the citrate lyase ligase and citrate lyase of Klebsiella pneumoniae and Haemophilus influenzae. Downstream of the citrate lyase cluster, a 1.4-kb open reading frame encoding a 52-kDa protein was found. The deduced protein is similar to CitG of the other bacteria, and its function remains unknown. Expression of the citCDEFG gene cluster in Escherichia coli led to the detection of a citrate lyase activity only in the presence of acetyl coenzyme A, which is a structural analog of the prosthetic group. This shows that the acetyl-ACP group of the citrate lyase form in E. coli is not complete or not linked to the protein.
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Affiliation(s)
- S Bekal
- Laboratoire de Microbiologie, UA INRA, ENS.BANA, Université de Bourgogne, Dijon , France
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Bott M, Dimroth P. Klebsiella pneumoniae genes for citrate lyase and citrate lyase ligase: localization, sequencing, and expression. Mol Microbiol 1994; 14:347-56. [PMID: 7830578 DOI: 10.1111/j.1365-2958.1994.tb01295.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In the course of studies on anaerobic citrate metabolism in Klebsiella pneumoniae, the DNA region upstream of the gene for the sodium-dependent citrate carrier (citS) was investigated. Nucleotide sequence analysis revealed a cluster of five new genes that were oriented inversely to citS and probably form an operon. The genes were named citCDEFG. Based on known protein sequence data, the gene products derived from citD, citE and citF could be identified as the gamma-, beta-, and alpha-subunits of citrate lyase, respectively. This enzyme catalyses the cleavage of citrate to oxaloacetate and acetate. The gene product derived from citC (calculated M(r) 38,476) exhibited no obvious similarity to other proteins. In the presence of acetate and ATP, cell extracts from a citC-expressing Escherichia coli strain were able to reactivate purified citrate lyase from K. pneumoniae that had been inactivated by chemical deacetylation of the prosthetic group. This represents 5-phosphoribosyl-dephospho-acetyl-coenzyme A which is covalently bound to serine-14 of the acyl carrier protein (gamma-subunit). CitC was thus identified as acetate:SH-citrate lyase ligase. The function of the gene product derived from citG (M(r) 32,645) has not yet been identified. Expression of the citCDEFG gene cluster in E. coli led to the formation of citrate lyase which was active only in the presence of acetyl-coenzyme A, a compound known to substitute for the prosthetic group. These and other data strongly indicated that the enzyme synthesized in E. coli lacked its prosthetic group. Thus, additional genes besides citCDEFG appear to be required for the formation of holo-citrate lyase.
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Affiliation(s)
- M Bott
- Mikrobiologisches Institut, Eidgenössische Technische Hochschule, Zürich, Switzerland
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19
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Abstract
For many bacteria Na+ bioenergetics is important as a link between exergonic and endergonic reactions in the membrane. This article focusses on two primary Na+ pumps in bacteria, the Na(+)-translocating oxaloacetate decarboxylase of Klebsiella pneumoniae and the Na(+)-translocating F1Fo ATPase of Propionigenium modestum. Oxaloacetate decarboxylase is an essential enzyme of the citrate fermentation pathway and has the additional function to conserve the free energy of decarboxylation by conversion into a Na+ gradient. Oxaloacetate decarboxylase is composed of three different subunits and the related methylmalonyl-CoA decarboxylase consists of five different subunits. The genes encoding these enzymes have been cloned and sequenced. Remarkable are large areas of complete sequence identity in the integral membrane-bound beta-subunits including two conserved aspartates that may be important for Na+ translocation. The coupling ratio of the decarboxylase Na+ pumps depended on delta muNa+ and decreased from two to zero Na+ uptake per decarboxylation event as delta mu Na+ increased from zero to the steady state level. In P. modestum, delta mu Na+ is generated in the course of succinate fermentation to propionate and CO2. This delta mu Na+ is used by a unique Na(+)-translocating F1Fo ATPase for ATP synthesis. The enzyme is related to H(+)-translocating F1Fo ATPases. The Fo part is entirely responsible for the coupling of ion specificity. A hybrid ATPase formed by in vivo complementation of an Escherichia coli deletion mutant was completely functional as a Na(+)-ATP synthase conferring the E. coli strain the ability of Na(+)-dependent growth on succinate. The hybrid consisted of subunits a, c, b, delta and part of alpha from P. modestum and of the remaining subunits from E. coli. Studies on Na+ translocation through the Fo part of the P. modestum ATPase revealed typical transporter-like properties. Sodium ions specifically protected the ATPase from the modification of glutamate-65 in subunit c by dicyclohexylcarbodiimide in a pH-dependent manner indicating that the Na+ binding site is at this highly conserved acidic amino acid residue of subunit c within the middle of the membrane.
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Affiliation(s)
- P Dimroth
- Mikrobiologisches Institut, Eidgenössische Technische Hochschule, ETH-Zentrum, Zürich, Switzerland
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Clark DP. Molybdenum cofactor negative mutants ofEscherichia coliuse citrate anaerobically. FEMS Microbiol Lett 1990. [DOI: 10.1111/j.1574-6968.1990.tb04027.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Antranikian G, Gottschalk G. Phosphorylation of citrate lyase ligase in Clostridium sphenoides and regulation of anaerobic citrate metabolism in other bacteria. Biochimie 1989; 71:1029-37. [PMID: 2512994 DOI: 10.1016/0300-9084(89)90107-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Since anaerobic bacteria cannot take advantage of citrate oxidation through the reactions of the tricarboxylic acid cycle special enzymes are needed for its fermentation. The activity of citrate lyase (the key enzyme of the citrate fermentation pathway) is in most cases strictly controlled by acetylation/deacetylation and configurational changes. In order to efficiently regulate citrate metabolism the activity of various regulatory enzymes, that modulate citrate lyase activity, are in turn under stringent control. Covalent modification by phosphorylation/dephosphorylation and electron transport dependent processes are some of the regulatory mechanisms that are here involved. L-Glutamate, which signals the availability of citrate, plays a central role in the regulation of citrate metabolism by influencing the enzymes that are acting in a complex cascade system.
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Affiliation(s)
- G Antranikian
- Institut für Mikrobiologie der Georg-August Universität Göttingen, FRC
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Ishii M, Igarashi Y, Kodama T. Purification and characterization of ATP:citrate lyase from Hydrogenobacter thermophilus TK-6. J Bacteriol 1989; 171:1788-92. [PMID: 2703459 PMCID: PMC209823 DOI: 10.1128/jb.171.4.1788-1792.1989] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
ATP:citrate lyase [ATP citrate (pro-3S)-lyase; EC 4.1.3.8] was purified and characterized from the cells of Hydrogenobacter thermophilus, an aerobic, thermophilic, hydrogen-oxidizing bacterium which fixes carbon dioxide by a reductive carboxylic acid cycle. The enzyme was quite stable, even in the absence of sulfhydryl reagents. Optimum pH for reaction was 6.7 to 6.9, and optimum temperature was around 80 degrees C. The molecular weight of native enzyme was estimated to be 260,000 by gel filtration analysis, and that of a subunit was estimated to be 43,000 by sodium dodecyl sulfate-polyacrylamide gel analysis. Km values for reaction components were as follows: citrate, 6.25 mM; ATP, 650 microM; coenzyme A, 40.8 microM; and Mg2+, 8 mM. The enzyme showed citrate synthase activity in the presence of Mg2+, but the reaction rate was very low (less than 1/200 of the lyase activity).
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Affiliation(s)
- M Ishii
- Department of Agricultural Chemistry, University of Tokyo, Japan
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Deutscher J, Saier MH. Protein Phosphorylation in Bacteria?Regulation of Gene Expression, Transport Functions, and Metabolic Processes. ACTA ACUST UNITED AC 1988. [DOI: 10.1002/anie.198810401] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Deutscher J, Saier MH. Proteinphosphorylierung in Bakterien – Regulation von Genexpression, Transportfunktionen und Stoffwechselvorgängen. Angew Chem Int Ed Engl 1988. [DOI: 10.1002/ange.19881000807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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