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Cao W, Huang C, Zhou X, Zhou S, Deng Y. Engineering two-component systems for advanced biosensing: From architecture to applications in biotechnology. Biotechnol Adv 2024; 75:108404. [PMID: 39002783 DOI: 10.1016/j.biotechadv.2024.108404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 06/05/2024] [Accepted: 07/07/2024] [Indexed: 07/15/2024]
Abstract
Two-component systems (TCSs) are prevalent signaling pathways in bacteria. These systems mediate phosphotransfer between histidine kinase and a response regulator, facilitating responses to diverse physical, chemical, and biological stimuli. Advancements in synthetic and structural biology have repurposed TCSs for applications in monitoring heavy metals, disease-associated biomarkers, and the production of bioproducts. However, the utility of many TCS biosensors is hindered by undesired performance due to the lack of effective engineering methods. Here, we briefly discuss the architectures and regulatory mechanisms of TCSs. We also summarize the recent advancements in TCS engineering by experimental or computational-based methods to fine-tune the biosensor functional parameters, such as response curve and specificity. Engineered TCSs have great potential in the medical, environmental, and biorefinery fields, demonstrating a crucial role in a wide area of biotechnology.
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Affiliation(s)
- Wenyan Cao
- School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Chao Huang
- School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Xuan Zhou
- School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Shenghu Zhou
- School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, China.
| | - Yu Deng
- School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, China.
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2
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Zhao Q, Yao F, Li W, Liu S, Bi S. Identification of a dCache-type chemoreceptor in Campylobacter jejuni that specifically mediates chemotaxis towards methyl pyruvate. Front Microbiol 2024; 15:1400284. [PMID: 38784811 PMCID: PMC11111895 DOI: 10.3389/fmicb.2024.1400284] [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: 03/13/2024] [Accepted: 04/25/2024] [Indexed: 05/25/2024] Open
Abstract
The foodborne pathogenic bacterium Campylobacter jejuni utilizes chemotaxis to assist in the colonization of host niches. A key to revealing the relationship among chemotaxis and pathogenicity is the discovery of signaling molecules perceived by the chemoreceptors. The C. jejuni chemoreceptor Tlp11 is encoded by the highly infective C. jejuni strains. In the present study, we report that the dCache-type ligand-binding domain (LBD) of C. jejuni ATCC 33560 Tlp11 binds directly to novel ligands methyl pyruvate, toluene, and quinoline using the same pocket. Methyl pyruvate elicits a strong chemoattractant response, while toluene and quinoline function as the antagonists without triggering chemotaxis. The sensory LBD was used to control heterologous proteins by constructing chimeras, indicating that the signal induced by methyl pyruvate is transmitted across the membrane. In addition, bioinformatics and experiments revealed that the dCache domains with methyl pyruvate-binding sites and ability are widely distributed in the order Campylobacterales. This is the first report to identify the class of dCache chemoreceptors that bind to attractant methyl pyruvate and antagonists toluene and quinoline. Our research provides a foundation for understanding the chemotaxis and virulence of C. jejuni and lays a basis for the control of this foodborne pathogen.
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Affiliation(s)
- Qi Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Fulian Yao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Wei Li
- Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan, China
| | - Shuangjiang Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
- State Key Laboratory of Microbial Resources, and Environmental Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Shuangyu Bi
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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3
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Mao Y, Huang C, Zhou X, Han R, Deng Y, Zhou S. Genetically Encoded Biosensor Engineering for Application in Directed Evolution. J Microbiol Biotechnol 2023; 33:1257-1267. [PMID: 37449325 PMCID: PMC10619561 DOI: 10.4014/jmb.2304.04031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/03/2023] [Accepted: 06/06/2023] [Indexed: 07/18/2023]
Abstract
Although rational genetic engineering is nowadays the favored method for microbial strain improvement, building up mutant libraries based on directed evolution for improvement is still in many cases the better option. In this regard, the demand for precise and efficient screening methods for mutants with high performance has stimulated the development of biosensor-based high-throughput screening strategies. Genetically encoded biosensors provide powerful tools to couple the desired phenotype to a detectable signal, such as fluorescence and growth rate. Herein, we review recent advances in engineering several classes of biosensors and their applications in directed evolution. Furthermore, we compare and discuss the screening advantages and limitations of two-component biosensors, transcription-factor-based biosensors, and RNA-based biosensors. Engineering these biosensors has focused mainly on modifying the expression level or structure of the biosensor components to optimize the dynamic range, specificity, and detection range. Finally, the applications of biosensors in the evolution of proteins, metabolic pathways, and genome-scale metabolic networks are described. This review provides potential guidance in the design of biosensors and their applications in improving the bioproduction of microbial cell factories through directed evolution.
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Affiliation(s)
- Yin Mao
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
| | - Chao Huang
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
| | - Xuan Zhou
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
| | - Runhua Han
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Yu Deng
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
| | - Shenghu Zhou
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P.R. China
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4
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Cheng J, Hu J, Geng F, Nie S. Bacteroides utilization for dietary polysaccharides and their beneficial effects on gut health. FOOD SCIENCE AND HUMAN WELLNESS 2022. [DOI: 10.1016/j.fshw.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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5
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Chen X, Bi S, Ma X, Sourjik V, Lai L. Discovery of a New Chemoeffector for Escherichia coli Chemoreceptor Tsr and Identification of a Molecular Mechanism of Repellent Sensing. ACS BIO & MED CHEM AU 2022; 2:386-394. [PMID: 37102165 PMCID: PMC10125284 DOI: 10.1021/acsbiomedchemau.1c00055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Motile bacteria use chemotaxis to search for nutrients and escape from harmful chemicals. While the sensing mechanisms for chemical attractants are well established, the molecular details of chemorepellent detection are poorly understood. Here, by using combined computational and experimental approaches to screen potential chemoeffectors for the Escherichia coli chemoreceptor Tsr, we identified a specific chemorepellent, 1-aminocyclohexanecarboxylic acid (ACHC). Our study strongly suggests that ACHC directly binds to the periplasmic sensory domain of Tsr and competes with l-serine, the amino acid attractant of Tsr. We further characterized the binding features of l-serine, ACHC, and l-leucine (a natural repellent that binds Tsr) and found that Asn68 plays a key role in mediating chemotactic response. Mutating Asn68 to Ala inverted the response to l-leucine from a repellent to an attractant. Our study provides important insights into the molecular mechanisms of ligand sensing via bacterial chemoreceptors.
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Affiliation(s)
- Xi Chen
- BNLMS,
Peking-Tsinghua Center for Life Sciences at College of Chemistry and
Molecular Engineering, Peking University, Beijing 100871, China
- Center
for Quantitative Biology, Academy of Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Shuangyu Bi
- Max
Planck Institute for Terrestrial Microbiology & LOEWE Center for
Synthetic Microbiology (SYNMIKRO), Marburg 35043, Germany
- State
Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Xiaomin Ma
- BNLMS,
Peking-Tsinghua Center for Life Sciences at College of Chemistry and
Molecular Engineering, Peking University, Beijing 100871, China
- Center
for Quantitative Biology, Academy of Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Victor Sourjik
- Max
Planck Institute for Terrestrial Microbiology & LOEWE Center for
Synthetic Microbiology (SYNMIKRO), Marburg 35043, Germany
| | - Luhua Lai
- BNLMS,
Peking-Tsinghua Center for Life Sciences at College of Chemistry and
Molecular Engineering, Peking University, Beijing 100871, China
- Center
for Quantitative Biology, Academy of Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
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6
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Liu S, Feng J, Sun T, Xu B, Zhang J, Li G, Zhou J, Jiang J. The Synthesis and Assembly of a Truncated Cyanophage Genome and Its Expression in a Heterogenous Host. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081234. [PMID: 36013413 PMCID: PMC9410186 DOI: 10.3390/life12081234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/16/2022]
Abstract
Cyanophages play an important role in regulating the dynamics of cyanobacteria communities in the hydrosphere, representing a promising biological control strategy for cyanobacterial blooms. Nevertheless, most cyanophages are host-specific, making it difficult to control blooming cyanobacteria via single or multiple cyanophages. In order to address the issue, we explore the interaction between cyanophages and their heterologous hosts, with the aim of revealing the principles of designing and constructing an artificial cyanophage genome towards multiple cyanobacterial hosts. In the present study, we use synthetic biological approaches to assess the impact of introducing a fragment of cyanophage genome into a heterologous cyanobacterium under a variety of environmental conditions. Based on a natural cyanophage A-4L genome (41,750 bp), a truncated cyanophage genome Syn-A-4-8 is synthesized and assembled in Saccharomyces cerevisiae. We found that a 351-15,930 bp area of the A-4L genome has a fragment that is lethal to Escherichia coli during the process of attempting to assemble the full-length A-4L genome. Syn-A-4-8 was successfully introduced into E. coli and then transferred into the model cyanobacterium Synechococcus elongatus PCC 7942 (Syn7942) via conjugation. Although no significant phenotypes of Syn7942 carrying Syn-A-4-8 (LS-02) could be observed under normal conditions, its growth exhibited a prolonged lag phase compared to that of the control strain under 290-millimolar NaCl stress. Finally, the mechanisms of altered salt tolerance in LS-02 were revealed through comparative transcriptomics, and ORF25 and ORF26 on Syn-A-4-8 turned out to be the key genes causing the phenotype. Our research represents an important attempt in designing artificial cyanophages towards multiple hosts, and offers new future insights into the control of cyanobacterial blooms.
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Affiliation(s)
- Shujing Liu
- School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Jia Feng
- School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Tao Sun
- School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin 300072, China
| | - Bonan Xu
- School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Jiabao Zhang
- School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Guorui Li
- School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Jianting Zhou
- School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
- Frontier Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, China
- Correspondence: (J.Z.); (J.J.)
| | - Jianlan Jiang
- School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
- Frontier Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, China
- Correspondence: (J.Z.); (J.J.)
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7
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Colin R, Ni B, Laganenka L, Sourjik V. Multiple functions of flagellar motility and chemotaxis in bacterial physiology. FEMS Microbiol Rev 2021; 45:fuab038. [PMID: 34227665 PMCID: PMC8632791 DOI: 10.1093/femsre/fuab038] [Citation(s) in RCA: 111] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/02/2021] [Indexed: 12/13/2022] Open
Abstract
Most swimming bacteria are capable of following gradients of nutrients, signaling molecules and other environmental factors that affect bacterial physiology. This tactic behavior became one of the most-studied model systems for signal transduction and quantitative biology, and underlying molecular mechanisms are well characterized in Escherichia coli and several other model bacteria. In this review, we focus primarily on less understood aspect of bacterial chemotaxis, namely its physiological relevance for individual bacterial cells and for bacterial populations. As evident from multiple recent studies, even for the same bacterial species flagellar motility and chemotaxis might serve multiple roles, depending on the physiological and environmental conditions. Among these, finding sources of nutrients and more generally locating niches that are optimal for growth appear to be one of the major functions of bacterial chemotaxis, which could explain many chemoeffector preferences as well as flagellar gene regulation. Chemotaxis might also generally enhance efficiency of environmental colonization by motile bacteria, which involves intricate interplay between individual and collective behaviors and trade-offs between growth and motility. Finally, motility and chemotaxis play multiple roles in collective behaviors of bacteria including swarming, biofilm formation and autoaggregation, as well as in their interactions with animal and plant hosts.
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Affiliation(s)
- Remy Colin
- Max Planck Institute for Terrestrial Microbiology & Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, Marburg D-35043, Germany
| | - Bin Ni
- Max Planck Institute for Terrestrial Microbiology & Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, Marburg D-35043, Germany
- College of Resources and Environmental Science, National Academy of Agriculture Green Development, China Agricultural University, Yuanmingyuan Xilu No. 2, Beijing 100193, China
| | - Leanid Laganenka
- Institute of Microbiology, D-BIOL, ETH Zürich, Vladimir-Prelog-Weg 4, Zürich 8093, Switzerland
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology & Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, Marburg D-35043, Germany
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8
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Gushchin I, Aleksenko VA, Orekhov P, Goncharov IM, Nazarenko VV, Semenov O, Remeeva A, Gordeliy V. Nitrate- and Nitrite-Sensing Histidine Kinases: Function, Structure, and Natural Diversity. Int J Mol Sci 2021; 22:5933. [PMID: 34072989 PMCID: PMC8199190 DOI: 10.3390/ijms22115933] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 12/18/2022] Open
Abstract
Under anaerobic conditions, bacteria may utilize nitrates and nitrites as electron acceptors. Sensitivity to nitrous compounds is achieved via several mechanisms, some of which rely on sensor histidine kinases (HKs). The best studied nitrate- and nitrite-sensing HKs (NSHKs) are NarQ and NarX from Escherichia coli. Here, we review the function of NSHKs, analyze their natural diversity, and describe the available structural information. In particular, we show that around 6000 different NSHK sequences forming several distinct clusters may now be found in genomic databases, comprising mostly the genes from Beta- and Gammaproteobacteria as well as from Bacteroidetes and Chloroflexi, including those from anaerobic ammonia oxidation (annamox) communities. We show that the architecture of NSHKs is mostly conserved, although proteins from Bacteroidetes lack the HAMP and GAF-like domains yet sometimes have PAS. We reconcile the variation of NSHK sequences with atomistic models and pinpoint the structural elements important for signal transduction from the sensor domain to the catalytic module over the transmembrane and cytoplasmic regions spanning more than 200 Å.
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Affiliation(s)
- Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (V.A.A.); (P.O.); (I.M.G.); (V.V.N.); (O.S.); (A.R.)
| | - Vladimir A. Aleksenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (V.A.A.); (P.O.); (I.M.G.); (V.V.N.); (O.S.); (A.R.)
| | - Philipp Orekhov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (V.A.A.); (P.O.); (I.M.G.); (V.V.N.); (O.S.); (A.R.)
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Ivan M. Goncharov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (V.A.A.); (P.O.); (I.M.G.); (V.V.N.); (O.S.); (A.R.)
| | - Vera V. Nazarenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (V.A.A.); (P.O.); (I.M.G.); (V.V.N.); (O.S.); (A.R.)
| | - Oleg Semenov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (V.A.A.); (P.O.); (I.M.G.); (V.V.N.); (O.S.); (A.R.)
| | - Alina Remeeva
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (V.A.A.); (P.O.); (I.M.G.); (V.V.N.); (O.S.); (A.R.)
| | - Valentin Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (V.A.A.); (P.O.); (I.M.G.); (V.V.N.); (O.S.); (A.R.)
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, 38000 Grenoble, France
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
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9
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Mohapatra B, Phale PS. Microbial Degradation of Naphthalene and Substituted Naphthalenes: Metabolic Diversity and Genomic Insight for Bioremediation. Front Bioeng Biotechnol 2021; 9:602445. [PMID: 33791281 PMCID: PMC8006333 DOI: 10.3389/fbioe.2021.602445] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 02/09/2021] [Indexed: 12/21/2022] Open
Abstract
Low molecular weight polycyclic aromatic hydrocarbons (PAHs) like naphthalene and substituted naphthalenes (methylnaphthalene, naphthoic acids, 1-naphthyl N-methylcarbamate, etc.) are used in various industries and exhibit genotoxic, mutagenic, and/or carcinogenic effects on living organisms. These synthetic organic compounds (SOCs) or xenobiotics are considered as priority pollutants that pose a critical environmental and public health concern worldwide. The extent of anthropogenic activities like emissions from coal gasification, petroleum refining, motor vehicle exhaust, and agricultural applications determine the concentration, fate, and transport of these ubiquitous and recalcitrant compounds. Besides physicochemical methods for cleanup/removal, a green and eco-friendly technology like bioremediation, using microbes with the ability to degrade SOCs completely or convert to non-toxic by-products, has been a safe, cost-effective, and promising alternative. Various bacterial species from soil flora belonging to Proteobacteria (Pseudomonas, Pseudoxanthomonas, Comamonas, Burkholderia, and Novosphingobium), Firmicutes (Bacillus and Paenibacillus), and Actinobacteria (Rhodococcus and Arthrobacter) displayed the ability to degrade various SOCs. Metabolic studies, genomic and metagenomics analyses have aided our understanding of the catabolic complexity and diversity present in these simple life forms which can be further applied for efficient biodegradation. The prolonged persistence of PAHs has led to the evolution of new degradative phenotypes through horizontal gene transfer using genetic elements like plasmids, transposons, phages, genomic islands, and integrative conjugative elements. Systems biology and genetic engineering of either specific isolates or mock community (consortia) might achieve complete, rapid, and efficient bioremediation of these PAHs through synergistic actions. In this review, we highlight various metabolic routes and diversity, genetic makeup and diversity, and cellular responses/adaptations by naphthalene and substituted naphthalene-degrading bacteria. This will provide insights into the ecological aspects of field application and strain optimization for efficient bioremediation.
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Affiliation(s)
- Balaram Mohapatra
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Prashant S Phale
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
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10
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Ahmad F, Zhu D, Sun J. Bacterial chemotaxis: a way forward to aromatic compounds biodegradation. ENVIRONMENTAL SCIENCES EUROPE 2020; 32:52. [DOI: 10.1186/s12302-020-00329-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/23/2020] [Indexed: 07/23/2024]
Abstract
AbstractWorldwide industrial development has released hazardous polycyclic aromatic compounds into the environment. These pollutants need to be removed to improve the quality of the environment. Chemotaxis mechanism has increased the bioavailability of these hydrophobic compounds to microorganisms. The mechanism, however, is poorly understood at the ligand and chemoreceptor interface. Literature is unable to furnish a compiled review of already published data on up-to-date research on molecular aspects of chemotaxis mechanism, ligand and receptor-binding mechanism, and downstream signaling machinery. Moreover, chemotaxis-linked biodegradation of aromatic compounds is required to understand the chemotaxis role in biodegradation better. To fill this knowledge gap, the current review is an attempt to cover PAHs occurrence, chemical composition, and potential posed risks to humankind. The review will cover the aspects of microbial signaling mechanism, the structural diversity of methyl-accepting chemotaxis proteins at the molecular level, discuss chemotaxis mechanism role in biodegradation of aromatic compounds in model bacterial genera, and finally conclude with the potential of bacterial chemotaxis for aromatics biodegradation.
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11
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Bacterial flagellar motor as a multimodal biosensor. Methods 2020; 193:5-15. [PMID: 32640316 DOI: 10.1016/j.ymeth.2020.06.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/04/2020] [Accepted: 06/22/2020] [Indexed: 01/05/2023] Open
Abstract
Bacterial Flagellar Motor is one of nature's rare rotary molecular machines. It enables bacterial swimming and it is the key part of the bacterial chemotactic network, one of the best studied chemical signalling networks in biology, which enables bacteria to direct its movement in accordance with the chemical environment. The network can sense down to nanomolar concentrations of specific chemicals on the time scale of seconds. Motor's rotational speed is linearly proportional to the electrochemical gradients of either proton or sodium driving ions, while its direction is regulated by the chemotactic network. Recently, it has been discovered that motor is also a mechanosensor. Given these properties, we discuss the motor's potential to serve as a multifunctional biosensor and a tool for characterising and studying the external environment, the bacterial physiology itself and single molecular motor biophysics.
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12
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Chemotaxis of Pseudomonas putida F1 to Alcohols Is Mediated by the Carboxylic Acid Receptor McfP. Appl Environ Microbiol 2019; 85:AEM.01625-19. [PMID: 31471307 DOI: 10.1128/aem.01625-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 08/29/2019] [Indexed: 01/08/2023] Open
Abstract
Although alcohols are toxic to many microorganisms, they are good carbon and energy sources for some bacteria, including many pseudomonads. However, most studies that have examined chemosensory responses to alcohols have reported that alcohols are sensed as repellents, which is consistent with their toxic properties. In this study, we examined the chemotaxis of Pseudomonas putida strain F1 to n-alcohols with chain lengths of 1 to 12 carbons. P. putida F1 was attracted to all n-alcohols that served as growth substrates (C2 to C12) for the strain, and the responses were induced when cells were grown in the presence of alcohols. By assaying mutant strains lacking single or multiple methyl-accepting chemotaxis proteins, the receptor mediating the response to C2 to C12 alcohols was identified as McfP, the ortholog of the P. putida strain KT2440 receptor for C2 and C3 carboxylic acids. Besides being a requirement for the response to n-alcohols, McfP was required for the response of P. putida F1 to pyruvate, l-lactate, acetate, and propionate, which are detected by the KT2440 receptor, and the medium- and long-chain carboxylic acids hexanoic acid and dodecanoic acid. β-Galactosidase assays of P. putida F1 carrying an mcfP-lacZ transcriptional fusion showed that the mcfP gene is not induced in response to alcohols. Together, our results are consistent with the idea that the carboxylic acids generated from the oxidation of alcohols are the actual attractants sensed by McfP in P. putida F1, rather than the alcohols themselves.IMPORTANCE Alcohols, released as fermentation products and produced as intermediates in the catabolism of many organic compounds, including hydrocarbons and fatty acids, are common components of the microbial food web in soil and sediments. Although they serve as good carbon and energy sources for many soil bacteria, alcohols have primarily been reported to be repellents rather than attractants for motile bacteria. Little is known about how alcohols are sensed by microbes in the environment. We report here that catabolizable n-alcohols with linear chains of up to 12 carbons serve as attractants for the soil bacterium Pseudomonas putida, and rather than being detected directly, alcohols appear to be catabolized to acetate, which is then sensed by a specific cell-surface chemoreceptor protein.
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