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Chen J, Liu K, Liu Y. Synergistic molecular mechanism of degradation in dye wastewater by Rhodopseudomonas palustris intimately coupled carbon nanotube - Silver modified titanium dioxide photocatalytic composite with sodium alginate. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119913. [PMID: 38154222 DOI: 10.1016/j.jenvman.2023.119913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/07/2023] [Accepted: 12/17/2023] [Indexed: 12/30/2023]
Abstract
The intimately coupled photocatalysis and biodegradation (ICPB), which combined the advantages of high oxidation capacity of photocatalysis and high mineralization rate of biodegradation, has demonstrated excellent removal performance in the degradation of azo dyes with highly toxic, refractory, mutagenic and carcinogenic. In order to explore the metagenomics mechanism of the ICPB system, a novel ICPB was prepared by coupling Rhodopseudomonas palustris (R. Palustris), carbon nanotube - silver modified titanium dioxide photocatalytic composite (CNT-Ag -TiO2, CAT) and sodium alginate (SA) (R. palustris/CAT@SA, R-CAT). Metagenomics sequencing was used to investigate the molecular mechanism of adaptation and degradation of dyes by photosynthetic microorganisms and the adaptive and synergistic interaction between photosynthetic microorganisms and photocatalyst. Experiments on the adaptability and degradability of photosynthetic microorganisms have proved that low concentration azo dyes could be utilized as carbon sources for growth of photosynthetic microorganisms. Metagenomics sequencing revealed that R. palustris was the main degrading bacterium in photosynthetic microorganisms and the functional genes related to carbohydrate metabolism, biological regulation and catalytic activity were abundant. It was found that the addition of photocatalyst significantly up-regulated the functional genes related to the catabolic process, electron transport, oxidoreductase activity and superoxide metabolism of organic matter in the photosynthetic microorganisms. Moreover, many key gene such as alpha-amylase, 1-acyl-sn-glycerol-3-phosphate acyltransferase, aldehyde dehydrogenase enrichment in microbial basal metabolism, such as enoyl-CoA hydratase, malate dehydrogenase, glutathione S-transferase enrichment in degrading azo dyes and electron transport, and many key gene such as undecaprenyl-diphosphatase, carbon storage regulator, DNA ligase enrichment in response to dyes and photocatalysts were discovered. These findings would contribute to a comprehensive understanding of the mechanism of degradation of dye wastewater by ICPB system, a series of genes was produced to adapt to environmental changes, and played synergistic role in terms of intermediate product degradation and electron transfer for degrading azo dyes. The photosynthetic microorganisms might be a promising microorganism for constructing ICPB system.
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Affiliation(s)
- Junfeng Chen
- School of Life Sciences, Qufu Normal University, Qufu, 273165, PR China.
| | - Kai Liu
- School of Life Sciences, Qufu Normal University, Qufu, 273165, PR China
| | - Yanyan Liu
- School of Life Sciences, Qufu Normal University, Qufu, 273165, PR China
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2
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Godínez-Pérez CM, Loza A, Hurtado JM, Gutiérrez-Ríos RM. The benzoyl-CoA pathway serves as a genomic marker to identify the oxygen requirements in the degradation of aromatic hydrocarbons. Front Microbiol 2024; 14:1308626. [PMID: 38264488 PMCID: PMC10803450 DOI: 10.3389/fmicb.2023.1308626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/22/2023] [Indexed: 01/25/2024] Open
Abstract
The first step of anaerobic benzoate degradation is the formation of benzoyl-coenzyme A by benzoate-coenzyme A ligase (BCL). The anaerobic route is steered by benzoyl-CoA reductase, which promotes benzoyl-CoA breakdown, which is subsequently oxidized. In certain bacteria at low oxygen conditions, the aerobic metabolism of monoaromatic hydrocarbons occurs through the degradation Box pathway. These pathways have undergone experimental scrutiny in Alphaproteobacteria and Betaproteobacteria and have also been explored bioinformatically in representative Betaproteobacteria. However, there is a gap in our knowledge regarding the distribution of the benzoyl-CoA pathway and the evolutionary forces propelling its adaptation beyond that of representative bacteria. To address these questions, we used bioinformatic procedures to identify the BCLs and the lower pathways that transform benzoyl-CoA. These procedures included the identification of conserved motifs. As a result, we identified two motifs exclusive to BCLs, describing some of the catalytic properties of this enzyme. These motifs helped to discern BCLs from other aryl-CoA ligases effectively. The predicted BCLs and the enzymes of lower pathways were used as genomic markers for identifying aerobic, anaerobic, or hybrid catabolism, which we found widely distributed in Betaproteobacteria. Despite these enhancements, our approach failed to distinguish orthologs from a small cluster of paralogs exhibiting all the specified features to predict an ortholog. Nonetheless, the conducted phylogenetic analysis and the properties identified in the genomic context aided in formulating hypotheses about how this redundancy contributes to refining the catabolic strategy employed by these bacteria to degrade the substrates.
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Affiliation(s)
| | | | | | - Rosa-María Gutiérrez-Ríos
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
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3
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Kang X, Zhao X, Song X. Analysis of a novel strain Brevundimonas KX-1 capable of degrading 3-chlorocarbazole based on the whole genome sequence. Antonie Van Leeuwenhoek 2023; 116:577-593. [PMID: 37186067 DOI: 10.1007/s10482-023-01831-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 04/13/2023] [Indexed: 05/17/2023]
Abstract
In this study, a strain was isolated from a sewage treatment plant in Jiangsu Province, China. The strain was identified as Brevundimonas sp. KX-1. After 5 days, 50.2% 3-chlorocarbazole (3-CCZ) was degraded under the optimum condition as follows: 1 g/L starch, 30 °C, pH 6.5 and 50 mg/L 3-CCZ. The degradation of 3-CCZ by KX-1 conformed to the first-order kinetic model under different initial concentrations in this experiment. The intermediate product of 3-CCZ degradation was identified as (2E,4Z)-6-(2-amino-5-chlorophenyl)-2-hydroxy-6-oxohexa-2,4-dienoic acid. The activities of the meta-cleavage enzymes for biphenyl-2,3-diol (the analogs of intermediate product 2'-amino-5'-chloro-[1,1'-biphenyl]-2,3-diol) were measured with the crude extracts of cells grown in the presence of 3-CCZ. The complete genome of KX-1 was sequenced and compared with the Brevundimonas diminuta BZC3. BZC3 and KX-1 belonged to the same species, displaying the genetic similarity of 99%. But BZC3 could efficiently degrade gentamicin for the potential microbial function analysis. Compared with BZC3, KX-1 possessed the primary function annotations about transportation and metabolism of amino acids (6.65%) and the transportation and metabolism of carbohydrates (5.96%). In addition, KX-1 was rich in sucrose and starch metabolism pathways (ko00500) compared with the genome of BZC3, indicating the high efficiency of KX-1 for starch utilization during degradation. This article reveals the difference between strain KX-1 and bacteria of the same genus in terms of the whole genome sequence, demonstrating that KX-1 is a novel strain Brevundimonas with the ability to degrade 3-CCZ.
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Affiliation(s)
- Xin Kang
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Xiaoxiang Zhao
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
- , Bldg. 4, 2999 Renmin North Road, Songjiang District, Shanghai, 201620, People's Republic of China.
| | - Xinshan Song
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
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4
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The structure-function relationship of bacterial transcriptional regulators as a target for enhanced biodegradation of aromatic hydrocarbons. Microbiol Res 2022; 262:127087. [DOI: 10.1016/j.micres.2022.127087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 06/03/2022] [Accepted: 06/03/2022] [Indexed: 11/20/2022]
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5
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Cabral L, Giovanella P, Pellizzer EP, Teramoto EH, Kiang CH, Sette LD. Microbial communities in petroleum-contaminated sites: Structure and metabolisms. CHEMOSPHERE 2022; 286:131752. [PMID: 34426136 DOI: 10.1016/j.chemosphere.2021.131752] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 06/24/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
Over recent decades, hydrocarbon concentrations have been augmented in soil and water, mainly derived from accidents or operations that input crude oil and petroleum into the environment. Different techniques for remediation have been proposed and used to mitigate oil contamination. Among the available environmental recovery approaches, bioremediation stands out since these hydrocarbon compounds can be used as growth substrates for microorganisms. In turn, microorganisms can play an important role with significant contributions to the stabilization of impacted areas. In this review, we present the current knowledge about responses from natural microbial communities (using DNA barcoding, multiomics, and functional gene markers) and bioremediation experiments (microcosm and mesocosm) conducted in the presence of petroleum and chemical dispersants in different samples, including soil, sediment, and water. Additionally, we present metabolic mechanisms for aerobic/anaerobic hydrocarbon degradation and alternative pathways, as well as a summary of studies showing functional genes and other mechanisms involved in petroleum biodegradation processes.
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Affiliation(s)
- Lucélia Cabral
- Laboratório de Micologia Ambiental e Industrial (LAMAI), Departamento de Biologia Geral e Aplicada, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil
| | - Patricia Giovanella
- Laboratório de Micologia Ambiental e Industrial (LAMAI), Departamento de Biologia Geral e Aplicada, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil; Centro de Estudos Ambientais (CEA), Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil
| | - Elisa Pais Pellizzer
- Laboratório de Micologia Ambiental e Industrial (LAMAI), Departamento de Biologia Geral e Aplicada, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil
| | - Elias Hideo Teramoto
- Centro de Estudos Ambientais (CEA), Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil; Laboratório de Estudos de Bacias (LEBAC), Departamento de Geologia Aplicada, Instituto de Geociências e Ciências Exatas, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil
| | - Chang Hung Kiang
- Centro de Estudos Ambientais (CEA), Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil; Laboratório de Estudos de Bacias (LEBAC), Departamento de Geologia Aplicada, Instituto de Geociências e Ciências Exatas, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil
| | - Lara Durães Sette
- Laboratório de Micologia Ambiental e Industrial (LAMAI), Departamento de Biologia Geral e Aplicada, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil; Centro de Estudos Ambientais (CEA), Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rio Claro, SP, Brazil.
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6
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Saraiva JP, Bartholomäus A, Kallies R, Gomes M, Bicalho M, Coelho Kasmanas J, Vogt C, Chatzinotas A, Stadler P, Dias O, Nunes da Rocha U. OrtSuite: from genomes to prediction of microbial interactions within targeted ecosystem processes. Life Sci Alliance 2021; 4:4/12/e202101167. [PMID: 34580179 PMCID: PMC8500227 DOI: 10.26508/lsa.202101167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 12/01/2022] Open
Abstract
OrtSuite predicts synergistic species interactions using the genomic potential of microbial communities The high complexity found in microbial communities makes the identification of microbial interactions challenging. To address this challenge, we present OrtSuite, a flexible workflow to predict putative microbial interactions based on genomic content of microbial communities and targeted to specific ecosystem processes. The pipeline is composed of three user-friendly bash commands. OrtSuite combines ortholog clustering with genome annotation strategies limited to user-defined sets of functions allowing for hypothesis-driven data analysis such as assessing microbial interactions in specific ecosystems. OrtSuite matched, on average, 96% of experimentally verified KEGG orthologs involved in benzoate degradation in a known group of benzoate degraders. We evaluated the identification of putative synergistic species interactions using the sequenced genomes of an independent study that had previously proposed potential species interactions in benzoate degradation. OrtSuite is an easy-to-use workflow that allows for rapid functional annotation based on a user-curated database and can easily be extended to ecosystem processes where connections between genes and reactions are known. OrtSuite is an open-source software available at https://github.com/mdsufz/OrtSuite.
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Affiliation(s)
- João Pedro Saraiva
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | | | - René Kallies
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Marta Gomes
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Marcos Bicalho
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Jonas Coelho Kasmanas
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany.,Institute of Mathematics and Computer Sciences, University of Sao Paulo, Sao Carlos, Brazil.,Department of Computer Science, Bioinformatics Group, Interdisciplinary Center for Bioinformatics, and Competence Center for Scalable Data Services and Solutions Dresden/Leipzig, University of Leipzig, Leipzig, Germany
| | - Carsten Vogt
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Antonis Chatzinotas
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany.,Institute of Biology, Leipzig University, Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Peter Stadler
- Department of Computer Science, Bioinformatics Group, Interdisciplinary Center for Bioinformatics, and Competence Center for Scalable Data Services and Solutions Dresden/Leipzig, University of Leipzig, Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Institute for Theoretical Chemistry, University of Vienna, Wien, Austria.,Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia.,Santa Fe Institute, Santa Fe, NM, USA
| | - Oscar Dias
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Ulisses Nunes da Rocha
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
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7
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Liu L, Huang L, Yu D, Zhang G, Dong S. FeS 2 nanoparticles decorated carbonized Luffa cylindrica as biofilm substrates for fabricating high performance biosensors. Talanta 2021; 232:122416. [PMID: 34074404 DOI: 10.1016/j.talanta.2021.122416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/29/2021] [Accepted: 04/07/2021] [Indexed: 11/29/2022]
Abstract
A high-performance microbial biosensor was fabricated with a reasonably designed biofilm substrate, where the aerogel of carbonized Luffa cylindrica (LC) was used as the scaffold for loading biofilm and FeS2 nanoparticles (FeS2NPs) were employed to modify this aerogel (FeS2NPs/GelLC). The fabricated FeS2NPs/GelLC exhibited a spring-like structure similar with that of the raw LC, which facilitated the linkage of the scaffold and promoted its mechanical strength, and further prolonged the service period of the as-prepared biosensor from few days to two months. Meanwhile, the introduced FeS2NPs improved the microbial electron transfer of the biofilm and causing an increase in the sensor's signals from 155.0 ± 2.6 to 352.0 ± 17.1 nA and a decrease in the detection limit from 0.95 to 0.38 mg O L-1 (S/N = 3) for the detection of glucose-glutamic acid (GGA). More important, the FeS2NPs had been demonstrated to have the capability for modulating a persistent shift of the microbial community with organic pollutant biodegradability. Compared with the GelLC, the FeS2NPs/GelLC exhibited a promising performance for measuring the synthetic sewage and real water samples in BOD assay and an increasing inhibition-ratio for detecting 3,5-dichlorophenol (DCP) in toxicity assay. Based on the vast resource and renewability of LC, this work pave a new avenue for developing high-performance microbial biosensors that are expected to be the engineering production.
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Affiliation(s)
- Ling Liu
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, The High-tech North District, 4888 Sheng Bei Street, Changchun, 130102, PR China; State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, PR China; University of the Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Liang Huang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, PR China
| | - Dengbin Yu
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, The High-tech North District, 4888 Sheng Bei Street, Changchun, 130102, PR China; State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, PR China; University of the Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Guangxin Zhang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, The High-tech North District, 4888 Sheng Bei Street, Changchun, 130102, PR China; University of the Chinese Academy of Sciences, Beijing, 100049, PR China.
| | - Shaojun Dong
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, PR China; University of the Chinese Academy of Sciences, Beijing, 100049, PR China.
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8
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Suvorova IA, Gelfand MS. Comparative Analysis of the IclR-Family of Bacterial Transcription Factors and Their DNA-Binding Motifs: Structure, Positioning, Co-Evolution, Regulon Content. Front Microbiol 2021; 12:675815. [PMID: 34177859 PMCID: PMC8222616 DOI: 10.3389/fmicb.2021.675815] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/14/2021] [Indexed: 11/13/2022] Open
Abstract
The IclR-family is a large group of transcription factors (TFs) regulating various biological processes in diverse bacteria. Using comparative genomics techniques, we have identified binding motifs of IclR-family TFs, reconstructed regulons and analyzed their content, finding co-occurrences between the regulated COGs (clusters of orthologous genes), useful for future functional characterizations of TFs and their regulated genes. We describe two main types of IclR-family motifs, similar in sequence but different in the arrangement of the half-sites (boxes), with GKTYCRYW3-4RYGRAMC and TGRAACAN1-2TGTTYCA consensuses, and also predict that TFs in 32 orthologous groups have binding sites comprised of three boxes with alternating direction, which implies two possible alternative modes of dimerization of TFs. We identified trends in site positioning relative to the translational gene start, and show that TFs in 94 orthologous groups bind tandem sites with 18-22 nucleotides between their centers. We predict protein-DNA contacts via the correlation analysis of nucleotides in binding sites and amino acids of the DNA-binding domain of TFs, and show that the majority of interacting positions and predicted contacts are similar for both types of motifs and conform well both to available experimental data and to general protein-DNA interaction trends.
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Affiliation(s)
- Inna A Suvorova
- Institute for Information Transmission Problems of Russian Academy of Sciences (The Kharkevich Institute), Moscow, Russia
| | - Mikhail S Gelfand
- Institute for Information Transmission Problems of Russian Academy of Sciences (The Kharkevich Institute), Moscow, Russia.,Skolkovo Institute of Science and Technology, Moscow, Russia
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9
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Shi S, Yang L, Yang C, Li S, Zhao H, Ren L, Wang X, Lu F, Li Y, Zhao H. Function and Molecular Ecology Significance of Two Catechol-Degrading Gene Clusters in Pseudomonas putida ND6. J Microbiol Biotechnol 2021; 31:259-271. [PMID: 33323670 PMCID: PMC9705993 DOI: 10.4014/jmb.2009.09026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/06/2020] [Accepted: 12/08/2020] [Indexed: 12/15/2022]
Abstract
Many bacteria metabolize aromatic compounds via catechol as a catabolic intermediate, and possess multiple genes or clusters encoding catechol-cleavage enzymes. The presence of multiple isozyme-encoding genes is a widespread phenomenon that seems to give the carrying strains a selective advantage in the natural environment over those with only a single copy. In the naphthalene-degrading strain Pseudomonas putida ND6, catechol can be converted into intermediates of the tricarboxylic acid cycle via either the ortho- or meta-cleavage pathways. In this study, we demonstrated that the catechol ortho-cleavage pathway genes (catBICIAI and catBIICIIAII) on the chromosome play an important role. The catI and catII operons are co-transcribed, whereas catAI and catAII are under independent transcriptional regulation. We examined the binding of regulatory proteins to promoters. In the presence of cis-cis-muconate, a well-studied inducer of the cat gene cluster, CatRI and CatRII occupy an additional downstream site, designated as the activation binding site. Notably, CatRI binds to both the catI and catII promoters with high affinity, while CatRII binds weakly. This is likely caused by a T to G mutation in the G/T-N11-A motif. Specifically, we found that CatRI and CatRII regulate catBICIAI and catBIICIIAII in a cooperative manner, which provides new insights into naphthalene degradation.
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Affiliation(s)
- Sanyuan Shi
- Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P.R. China
| | - Liu Yang
- Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P.R. China
| | - Chen Yang
- Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P.R. China
| | - Shanshan Li
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710048, P.R. China
| | - Hong Zhao
- Tianjin Entry-Exit Inspection and Quarantine Bureau, Tianjin 00457, P.R. China
| | - Lu Ren
- Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P.R. China
| | - Xiaokang Wang
- Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P.R. China
| | - Fuping Lu
- Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P.R. China
| | - Ying Li
- China Animal Disease Control Center, Beijing 100000, P.R. China,Y. Li Phone: +86-10-59198969 Fax: +86-10-59198969 E-mail:
| | - Huabing Zhao
- Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P.R. China,Corresponding authors H. Zhao Phone: +86-22-60601958 Fax: +86-22-60602298 E-mail:
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10
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Abstract
There is growing interest in the use of associative, plant growth-promoting bacteria (PGPB) as biofertilizers to serve as a sustainable alternative for agriculture application. While a variety of mechanisms have been proposed to explain bacterial plant growth promotion, the molecular details of this process remain unclear. The plant rhizosphere harbors a diverse population of microorganisms, including beneficial plant growth-promoting bacteria (PGPB), that colonize plant roots and enhance growth and productivity. In order to specifically define bacterial traits that contribute to this beneficial interaction, we used high-throughput transposon mutagenesis sequencing (TnSeq) in two model root-bacterium systems associated with Setaria viridis: Azoarcus olearius DQS4T and Herbaspirillum seropedicae SmR1. This approach identified ∼100 significant genes for each bacterium that appeared to confer a competitive advantage for root colonization. Most of the genes identified specifically in A. olearius encoded metabolism functions, whereas genes identified in H. seropedicae were motility related, suggesting that each strain requires unique functions for competitive root colonization. Genes were experimentally validated by site-directed mutagenesis, followed by inoculation of the mutated bacteria onto S. viridis roots individually, as well as in competition with the wild-type strain. The results identify key bacterial functions involved in iron uptake, polyhydroxybutyrate metabolism, and regulation of aromatic metabolism as important for root colonization. The hope is that by improving our understanding of the molecular mechanisms used by PGPB to colonize plants, we can increase the adoption of these bacteria in agriculture to improve the sustainability of modern cropping systems.
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11
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Engevik MA, Danhof HA, Shrestha R, Chang-Graham AL, Hyser JM, Haag AM, Mohammad MA, Britton RA, Versalovic J, Sorg JA, Spinler JK. Reuterin disrupts Clostridioides difficile metabolism and pathogenicity through reactive oxygen species generation. Gut Microbes 2020; 12:1788898. [PMID: 32804011 PMCID: PMC7524292 DOI: 10.1080/19490976.2020.1795388] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/16/2020] [Accepted: 07/06/2020] [Indexed: 02/03/2023] Open
Abstract
Antibiotic resistance is one of the world's greatest public health challenges and adjunct probiotic therapies are strategies that could lessen this burden. Clostridioides difficile infection (CDI) is a prime example where adjunct probiotic therapies could decrease disease incidence through prevention. Human-derived Lactobacillus reuteri is a probiotic that produces the antimicrobial compound reuterin known to prevent C. difficile colonization of antibiotic-treated fecal microbial communities. However, the mechanism of inhibition is unclear. We show that reuterin inhibits C. difficile outgrowth from spores and vegetative cell growth, however, no effect on C. difficile germination or sporulation was observed. Consistent with published studies, we found that exposure to reuterin stimulated reactive oxygen species (ROS) in C. difficile, resulting in a concentration-dependent reduction in cell viability that was rescued by the antioxidant glutathione. Sublethal concentrations of reuterin enhanced the susceptibility of vegetative C. difficile to vancomycin and metronidazole treatment and reduced toxin synthesis by C. difficile. We also demonstrate that reuterin is protective against C. difficile toxin-mediated cellular damage in the human intestinal enteroid model. Overall, our results indicate that ROS are essential mediators of reuterin activity and show that reuterin production by L. reuteri is compatible as a therapeutic in a clinically relevant model.
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Affiliation(s)
- Melinda A. Engevik
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
| | - Heather A. Danhof
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Ritu Shrestha
- Department of Biology, Texas A&M University, College Station, TX, USA
| | | | - Joseph M. Hyser
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Anthony M. Haag
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Microbiome Center, Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Mahmoud A. Mohammad
- Department of Pediatrics, Children’s Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Robert A. Britton
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - James Versalovic
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Microbiome Center, Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Joseph A. Sorg
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - Jennifer K. Spinler
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Microbiome Center, Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
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Xiang W, Wei X, Tang H, Li L, Huang R. Complete Genome Sequence and Biodegradation Characteristics of Benzoic Acid-Degrading Bacterium Pseudomonas sp. SCB32. BIOMED RESEARCH INTERNATIONAL 2020; 2020:6146104. [PMID: 32714981 PMCID: PMC7354641 DOI: 10.1155/2020/6146104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 04/17/2020] [Indexed: 11/25/2022]
Abstract
Allelochemicals are metabolites produced by living organisms that have a detrimental effect on other species when released into the environment. These chemicals play critical roles in the problems associated with crop replanting. Benzoic acid is a representative allelochemical found in root exudates and rhizosphere soil of crops and inhibits crop growth. The bioremediation of allelochemicals by microorganisms is an efficient decontamination process. In this research, a bacterial strain capable of degrading benzoic acid as the sole carbon source was isolated. The genome of the strain was sequenced, and biodegradation characteristics and metabolic mechanisms were examined. Strain SCB32 was identified as Pseudomonas sp. based on 16S rRNA gene analysis coupled with physiological and biochemical analyses. The degradation rate of 800 mg L-1 benzoic acid by strain SCB32 was greater than 97.0% in 24 h. The complete genome of strain SCB32 was 6.3 Mbp with a GC content of 64.6% and 5960 coding genes. Potential benzoic acid degradation genes were found by comparison to the KEGG database. Some key intermediate metabolites of benzoic acid, such as catechol, were detected by gas chromatography-mass spectrometry. The biodegradation pathway of benzoic acid, the ortho pathway, is proposed for strain SCB32 based on combined data from genome annotation and mass spectrometry. Moreover, the benzoic acid degradation products from strain SCB32 were essentially nontoxic to lettuce seedlings, while seeds in the benzoic acid-treated group showed significant inhibition of germination. This indicates a possible application of strain SCB32 in the bioremediation of benzoic acid contamination in agricultural environments.
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Affiliation(s)
- Wei Xiang
- Department of Agronomy, Agricultural College of Guangxi University, Nanning 530004, China
| | - Xiaolan Wei
- Department of Agronomy, Agricultural College of Guangxi University, Nanning 530004, China
| | - Hui Tang
- Guangxi Institute of Botany, Chinese Academy of Sciences, Guilin 541006, China
| | - Liangbo Li
- Department of Agronomy, Agricultural College of Guangxi University, Nanning 530004, China
| | - Rongshao Huang
- Department of Agronomy, Agricultural College of Guangxi University, Nanning 530004, China
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Sanz D, García JL, Díaz E. Expanding the current knowledge and biotechnological applications of the oxygen-independent ortho-phthalate degradation pathway. Environ Microbiol 2020; 22:3478-3493. [PMID: 32510798 DOI: 10.1111/1462-2920.15119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/31/2020] [Accepted: 06/03/2020] [Indexed: 11/29/2022]
Abstract
ortho-Phthalate derives from industrially produced phthalate esters, which are massively used as plasticizers and constitute major emerging environmental pollutants. The pht pathway for the anaerobic bacterial biodegradation of o-phthalate involves its activation to phthaloyl-CoA followed by decarboxylation to benzoyl-CoA. Here, we have explored further the pht peripheral pathway in denitrifying bacteria and shown that it requires also an active transport system for o-phthalate uptake that belongs to the poorly characterized class of TAXI-TRAP transporters. The construction of a fully functional pht cassette combining both catabolic and transport genes allowed to expand the o-phthalate degradation ecological trait to heterologous hosts. Unexpectedly, the pht cassette also allowed the aerobic conversion of o-phthalate to benzoyl-CoA when coupled to a functional box central pathway. Hence, the pht pathway may constitute an evolutionary acquisition for o-phthalate degradation by bacteria that thrive either in anoxic environments or in environments that face oxygen limitations and that rely on benzoyl-CoA, rather than on catecholic central intermediates, for the aerobic catabolism of aromatic compounds. Finally, the recombinant pht cassette was used both to screen for functional aerobic box pathways in bacteria and to engineer recombinant biocatalysts for o-phthalate bioconversion into sustainable bioplastics, e.g., polyhydroxybutyrate, in plastic recycling industrial processes.
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Affiliation(s)
- David Sanz
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, Spain
| | - José L García
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, Spain
| | - Eduardo Díaz
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, Spain
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