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Mittal P, Sinha AK, Pandiyan A, Kumari L, Ray MK, Pavankumar TL. A type II toxin-antitoxin system is responsible for the cell death at low temperature in Pseudomonas syringae Lz4W lacking RNase R. J Biol Chem 2024; 300:107600. [PMID: 39059490 DOI: 10.1016/j.jbc.2024.107600] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 06/17/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
RNase R (encoded by the rnr gene) is a highly processive 3' → 5' exoribonuclease essential for the growth of the psychrotrophic bacterium Pseudomonas syringae Lz4W at low temperature. The cell death of a rnr deletion mutant at low temperature has been previously attributed to processing defects in 16S rRNA, defective ribosomal assembly, and inefficient protein synthesis. We recently showed that RNase R is required to protect P. syringae Lz4W from DNA damage and oxidative stress, independent of its exoribonuclease activity. Here, we show that the processing defect in 16S rRNA does not cause cell death of the rnr mutant of P. syringae at low temperature. Our results demonstrate that the rnr mutant of P. syringae Lz4W, complemented with a RNase R deficient in exoribonuclease function (RNase RD284A), is defective in 16S rRNA processing but can grow at 4 °C. This suggested that the processing defect in ribosomal RNAs is not a cause of the cold sensitivity of the rnr mutant. We further show that the rnr mutant accumulates copies of the indigenous plasmid pLz4W that bears a type II toxin-antitoxin (TA) system (P. syringae antitoxin-P. syringae toxin). This phenotype was rescued by overexpressing antitoxin psA in the rnr mutant, suggesting that activation of the type II TA system leads to cold sensitivity of the rnr mutant of P. syringae Lz4W. Here, we report a previously unknown functional relationship between the cold sensitivity of the rnr mutant and a type II TA system in P. syringae Lz4W.
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Affiliation(s)
- Pragya Mittal
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India; Celtic Renewables Ltd, Edinburgh Napier University, Edinburgh, UK.
| | - Anurag K Sinha
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India; National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Apuratha Pandiyan
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India
| | - Leela Kumari
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Malay K Ray
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Theetha L Pavankumar
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India; Department of Microbiology and Molecular Genetics, University of California, Davis, California, USA; Department of Molecular and Cellular Biology, University of California, Davis, California, USA.
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2
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Popova PG, Lagace MA, Tang G, Blakney AK. Effect of in vitro transcription conditions on yield of high quality messenger and self-amplifying RNA. Eur J Pharm Biopharm 2024; 198:114247. [PMID: 38462138 DOI: 10.1016/j.ejpb.2024.114247] [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: 10/16/2023] [Revised: 02/12/2024] [Accepted: 03/06/2024] [Indexed: 03/12/2024]
Abstract
Messenger RNA (mRNA) and self-amplifying RNA (saRNA) vaccines against SARS-CoV-2 produced using in vitro transcription (IVT) were clinically approved in 2020 and 2022, respectively. While the industrial production of mRNA using IVT has been extensively optimized, the optimal conditions for saRNA have been explored to a lesser extent. Most T7 polymerase IVT protocols have been specifically optimized for mRNA which is ∼5-10-fold smaller than saRNA and may have profound effects on both the quality and yield of longer transcripts. Here, we optimized IVT conditions for simultaneously increasing the yield of full-length transcripts and reducing dsRNA formation through Design of Experiments. Using a definitive screening approach, we found that the key parameters are temperature and magnesium in the outcome of RNA quality (% full length transcript) and yield in small scale synthesis. The most important parameter for reducing dsRNA formation for both mRNA and saRNA was Mg2+ concentration (10 mM). We observed that a lower temperature was vital for production of high quality saRNA transcripts. mRNA quality was optimal at higher Mg2+ concentration (>40 mM). High quality transcripts correspond to significantly reduced product yield for saRNA, but not for mRNA. The differences between mRNA and saRNA requirements for high quality product and the relationship between high quality large saRNA molecules and low temperature synthesis have not been reported previously. These findings are key for informing future IVT parameters design and optimization for smaller and larger RNA transcripts.
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Affiliation(s)
- Petya G Popova
- Michael Smith Laboratories, School of Biomedical Engineering, University of British Columbia, Canada
| | - Melissa A Lagace
- Michael Smith Laboratories, School of Biomedical Engineering, University of British Columbia, Canada
| | - George Tang
- Michael Smith Laboratories, School of Biomedical Engineering, University of British Columbia, Canada
| | - Anna K Blakney
- Michael Smith Laboratories, School of Biomedical Engineering, University of British Columbia, Canada.
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3
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Chauhan M, Kimothi A, Sharma A, Pandey A. Cold adapted Pseudomonas: ecology to biotechnology. Front Microbiol 2023; 14:1218708. [PMID: 37529326 PMCID: PMC10388556 DOI: 10.3389/fmicb.2023.1218708] [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: 05/08/2023] [Accepted: 06/26/2023] [Indexed: 08/03/2023] Open
Abstract
The cold adapted microorganisms, psychrophiles/psychrotolerants, go through several modifications at cellular and biochemical levels to alleviate the influence of low temperature stress conditions. The low temperature environments depend on these cold adapted microorganisms for various ecological processes. The ability of the microorganisms to function in cold environments depends on the strategies directly associated with cell metabolism, physicochemical constrains, and stress factors. Pseudomonas is one among such group of microorganisms which is predominant in cold environments with a wide range of ecological and biotechnological applications. Bioformulations of Pseudomonas spp., possessing plant growth promotion and biocontrol abilities for application under low temperature environments, are well documented. Further, recent advances in high throughput sequencing provide essential information regarding the prevalence of Pseudomonas in rhizospheres and their role in plant health. Cold adapted species of Pseudomonas are also getting recognition for their potential in biodegradation and bioremediation of environmental contaminants. Production of enzymes and bioactive compounds (primarily as an adaptation mechanism) gives way to their applications in various industries. Exopolysaccharides and various biotechnologically important enzymes, produced by cold adapted species of Pseudomonas, are making their way in food, textiles, and pharmaceuticals. The present review, therefore, aims to summarize the functional versatility of Pseudomonas with particular reference to its peculiarities along with the ecological and biotechnological applications.
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Affiliation(s)
- Mansi Chauhan
- Department of Microbiology, Graphic Era (Deemed to be University), Dehradun, Uttarakhand, India
| | - Ayushi Kimothi
- Department of Microbiology, Graphic Era (Deemed to be University), Dehradun, Uttarakhand, India
| | - Avinash Sharma
- National Centre for Cell Science, Pune, Maharashtra, India
| | - Anita Pandey
- Department of Biotechnology, Graphic Era (Deemed to be University), Dehradun, Uttarakhand, India
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Ramasamy KP, Mahawar L, Rajasabapathy R, Rajeshwari K, Miceli C, Pucciarelli S. Comprehensive insights on environmental adaptation strategies in Antarctic bacteria and biotechnological applications of cold adapted molecules. Front Microbiol 2023; 14:1197797. [PMID: 37396361 PMCID: PMC10312091 DOI: 10.3389/fmicb.2023.1197797] [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: 03/31/2023] [Accepted: 05/31/2023] [Indexed: 07/04/2023] Open
Abstract
Climate change and the induced environmental disturbances is one of the major threats that have a strong impact on bacterial communities in the Antarctic environment. To cope with the persistent extreme environment and inhospitable conditions, psychrophilic bacteria are thriving and displaying striking adaptive characteristics towards severe external factors including freezing temperature, sea ice, high radiation and salinity which indicates their potential in regulating climate change's environmental impacts. The review illustrates the different adaptation strategies of Antarctic microbes to changing climate factors at the structural, physiological and molecular level. Moreover, we discuss the recent developments in "omics" approaches to reveal polar "blackbox" of psychrophiles in order to gain a comprehensive picture of bacterial communities. The psychrophilic bacteria synthesize distinctive cold-adapted enzymes and molecules that have many more industrial applications than mesophilic ones in biotechnological industries. Hence, the review also emphasizes on the biotechnological potential of psychrophilic enzymes in different sectors and suggests the machine learning approach to study cold-adapted bacteria and engineering the industrially important enzymes for sustainable bioeconomy.
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Affiliation(s)
| | - Lovely Mahawar
- Department of Plant Physiology, Faculty of Agrobiology and Food Resources, Slovak University of Agriculture, Nitra, Slovakia
| | - Raju Rajasabapathy
- Department of Marine Science, Bharathidasan University, Tiruchirappalli, Tamilnadu, India
| | | | - Cristina Miceli
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Sandra Pucciarelli
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
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5
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Rai A, Saha SP, Manvar T, Bhattacharjee A. A shotgun approach to explore the bacterial diversity and a brief insight into the glycoside hydrolases of Samiti lake located in the Eastern Himalayas. J Genet Eng Biotechnol 2022; 20:162. [PMID: 36469176 PMCID: PMC9723087 DOI: 10.1186/s43141-022-00444-y] [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: 04/19/2022] [Accepted: 11/12/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND The Himalayas have always been an enigma and, being biodiversity hotspots, are considered extremely important from an ecological point of view. Recent advances in studies regarding high-altitude lakes have garnered relevant importance as these habitats could harbor potential psychrophilic and psychrotrophic microbes with bio-prospective applications. Contemplating the above scenario, the present study has been undertaken to understand the diversity and the functional capacities of the microbes thriving in this lake. RESULTS In our present study on Samiti Lake, the abundance of Proteobacteria as the major phylum was seen in both the soil and water samples. Incase of the ABSLW (water) and ABS1 (soil) sample, 148,066 and 239,754 predicted genes, were taken for functional analysis. The KEGG analysis showed that ABSLW and ABS1 had 122,911 and 160,268, genes assigned to KO terms respectively. Whereas in case of COG functional analysis, 104,334 and 130,191 genes were assigned to different COG classes for ABSLW and ABS1 respectively. Further, on studying the glycoside hydrolases, an abundance of GH13, GH2, GH3, GH43, and GH23 in both the soil and water samples were seen. CONCLUSION Our study has provided a comprehensive report about the bacterial diversity and functional capacities of microbes thriving in Samiti Lake. It has also thrown some light on the occurrence of glycoside hydrolases in this region, as they have numerous biotechnological applications in different sectors.
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Affiliation(s)
- Aditi Rai
- grid.412222.50000 0001 1188 5260Department of Microbiology, University of North Bengal, P.O. NBU, District Darjeeling, West Bengal, Pin-734013 India
| | - Shyama Prasad Saha
- grid.412222.50000 0001 1188 5260Department of Microbiology, University of North Bengal, P.O. NBU, District Darjeeling, West Bengal, Pin-734013 India
| | - Toral Manvar
- Xcelris Labs Ltd, Ahmedabad, Gujarat 380006 India
| | - Arindam Bhattacharjee
- grid.412222.50000 0001 1188 5260Department of Microbiology, University of North Bengal, P.O. NBU, District Darjeeling, West Bengal, Pin-734013 India
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6
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Cold-Active Enzymes and Their Potential Industrial Applications-A Review. Molecules 2022; 27:molecules27185885. [PMID: 36144621 PMCID: PMC9501442 DOI: 10.3390/molecules27185885] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/17/2022] Open
Abstract
More than 70% of our planet is covered by extremely cold environments, nourishing a broad diversity of microbial life. Temperature is the most significant parameter that plays a key role in the distribution of microorganisms on our planet. Psychrophilic microorganisms are the most prominent inhabitants of the cold ecosystems, and they possess potential cold-active enzymes with diverse uses in the research and commercial sectors. Psychrophiles are modified to nurture, replicate, and retain their active metabolic activities in low temperatures. Their enzymes possess characteristics of maximal activity at low to adequate temperatures; this feature makes them more appealing and attractive in biotechnology. The high enzymatic activity of psychrozymes at low temperatures implies an important feature for energy saving. These enzymes have proven more advantageous than their mesophilic and thermophilic counterparts. Therefore, it is very important to explore the efficiency and utility of different psychrozymes in food processing, pharmaceuticals, brewing, bioremediation, and molecular biology. In this review, we focused on the properties of cold-active enzymes and their diverse uses in different industries and research areas. This review will provide insight into the areas and characteristics to be improved in cold-active enzymes so that potential and desired enzymes can be made available for commercial purposes.
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7
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Abstract
Temperature impacts biological systems across all length and timescales. Cells and the enzymes that comprise them respond to temperature fluctuations on short timescales, and temperature can affect protein folding, the molecular composition of cells, and volume expansion. Entire ecosystems exhibit temperature-dependent behaviors, and global warming threatens to disrupt thermal homeostasis in microbes that are important for human and planetary health. Intriguingly, the growth rate of most species follows the Arrhenius law of equilibrium thermodynamics, with an activation energy similar to that of individual enzymes but with maximal growth rates and over temperature ranges that are species specific. In this review, we discuss how the temperature dependence of critical cellular processes, such as the central dogma and membrane fluidity, contributes to the temperature dependence of growth. We conclude with a discussion of adaptation to temperature shifts and the effects of temperature on evolution and on the properties of microbial ecosystems.
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Affiliation(s)
- Benjamin D Knapp
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA;
| | - Kerwyn Casey Huang
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA; .,Department of Bioengineering, Stanford University, Stanford, California, USA.,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA.,Chan Zuckerberg Biohub, San Francisco, California, USA
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8
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Pavankumar TL, Mittal P, Hallsworth JE. Molecular insights into the ecology of a psychrotolerant
Pseudomonas syringae. Environ Microbiol 2020; 23:3665-3681. [DOI: 10.1111/1462-2920.15304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Theetha L. Pavankumar
- Department of Microbiology and Molecular Genetics, Briggs Hall, One Shields Avenue University of California Davis CA USA
| | - Pragya Mittal
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine University of Edinburgh Crewe Road South, Edinburgh, EH42XU, Scotland UK
| | - John E. Hallsworth
- Institute for Global Food Security, School of Biological Sciences Queen's University Belfast 19 Chlorine Gardens, Belfast, BT9 5DL Northern Ireland UK
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9
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Teets NM, Gantz JD, Kawarasaki Y. Rapid cold hardening: ecological relevance, physiological mechanisms and new perspectives. ACTA ACUST UNITED AC 2020; 223:223/3/jeb203448. [PMID: 32051174 DOI: 10.1242/jeb.203448] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rapid cold hardening (RCH) is a type of phenotypic plasticity that allows ectotherms to quickly enhance cold tolerance in response to brief chilling (lasting minutes to hours). In this Review, we summarize the current state of knowledge of this important phenotype and provide new directions for research. As one of the fastest adaptive responses to temperature known, RCH allows ectotherms to cope with sudden cold snaps and to optimize their performance during diurnal cooling cycles. RCH and similar phenotypes have been observed across a diversity of ectotherms, including crustaceans, terrestrial arthropods, amphibians, reptiles, and fish. In addition to its well-defined role in enhancing survival to extreme cold, RCH also protects against nonlethal cold injury by preserving essential functions following cold stress, such as locomotion, reproduction, and energy balance. The capacity for RCH varies across species and across genotypes of the same species, indicating that RCH can be shaped by selection and is likely favored in thermally variable environments. Mechanistically, RCH is distinct from other rapid stress responses in that it typically does not involve synthesis of new gene products; rather, the existing cellular machinery regulates RCH through post-translational signaling mechanisms. However, the protective mechanisms that enhance cold hardiness are largely unknown. We provide evidence that RCH can be induced by multiple triggers in addition to low temperature, and that rapidly induced tolerance and cross-tolerance to a variety of environmental stressors may be a general feature of stress responses that requires further investigation.
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Affiliation(s)
- Nicholas M Teets
- Department of Entomology, University of Kentucky, Lexington, KY 40546, USA
| | - J D Gantz
- Biology Department, Hendrix College, Conway, AK 72032, USA
| | - Yuta Kawarasaki
- Department of Biology, Gustavus Adolphus College, Saint Peter, MN 56082, USA
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10
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Ernst FGM, Erber L, Sammler J, Jühling F, Betat H, Mörl M. Cold adaptation of tRNA nucleotidyltransferases: A tradeoff in activity, stability and fidelity. RNA Biol 2017; 15:144-155. [PMID: 29099323 DOI: 10.1080/15476286.2017.1391445] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Cold adaptation is an evolutionary process that has dramatic impact on enzymatic activity. Increased flexibility of the protein structure represents the main evolutionary strategy for efficient catalysis and reaction rates in the cold, but is achieved at the expense of structural stability. This results in a significant activity-stability tradeoff, as it was observed for several metabolic enzymes. In polymerases, however, not only reaction rates, but also fidelity plays an important role, as these enzymes have to synthesize copies of DNA and RNA as exact as possible. Here, we investigate the effects of cold adaptation on the highly accurate CCA-adding enzyme, an RNA polymerase that uses an internal amino acid motif within the flexible catalytic core as a template to synthesize the CCA triplet at tRNA 3'-ends. As the relative orientation of these residues determines nucleotide selection, we characterized how cold adaptation impacts template reading and fidelity. In a comparative analysis of closely related psychro-, meso-, and thermophilic enzymes, the cold-adapted polymerase shows a remarkable error rate during CCA synthesis in vitro as well as in vivo. Accordingly, CCA-adding activity at low temperatures is not only achieved at the expense of structural stability, but also results in a reduced polymerization fidelity.
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Affiliation(s)
- Felix G M Ernst
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
| | - Lieselotte Erber
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
| | - Joana Sammler
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
| | - Frank Jühling
- b INSERM Unit 1110 , Institute of Viral and Liver Diseases, University of Strasbourg , Strasbourg , France
| | - Heike Betat
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
| | - Mario Mörl
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
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11
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Zeng Z, Liu X, Yao J, Guo Y, Li B, Li Y, Jiao N, Wang X. Cold adaptation regulated by cryptic prophage excision in Shewanella oneidensis. ISME JOURNAL 2016; 10:2787-2800. [PMID: 27482926 PMCID: PMC5148205 DOI: 10.1038/ismej.2016.85] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/30/2016] [Accepted: 05/10/2016] [Indexed: 01/18/2023]
Abstract
Among the environmental stresses experienced by bacteria, temperature shifts are one of the most important. In this study, we discovered a novel cold adaptation mechanism in Shewanella oneidensis that occurs at the DNA level and is regulated by cryptic prophage excision. Previous studies on bacterial cold tolerance mainly focus on the structural change of cell membrane and changes at the RNA and protein levels. Whether or not genomic change can also contribute to this process has not been explored. Here we employed a whole-genome deep-sequencing method to probe the changes at DNA level in a model psychrotrophic bacteria strain. We found that temperature downshift induced a 10 000-fold increase of the excision of a novel P4-like cryptic prophage. Importantly, although prophage excision only occurred in a relatively small population of bacteria, it was able to facilitate biofilm formation and promote the survival of the entire population. This prophage excision affected cell physiology by disrupting a critical gene encoding transfer-messenger RNA (tmRNA). In addition, we found that the histone-like nucleoid-structuring protein (H-NS) could silence prophage excision via binding to the promoter of the putative excisionase gene at warm temperatures. H-NS level was reduced at cold temperatures, leading to de-repression of prophage excision. Collectively, our results reveal that cryptic prophage excision acts as a regulatory switch to enable the survival of the host at low temperature by controlling the activity of tmRNA and biofilm formation.
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Affiliation(s)
- Zhenshun Zeng
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Xiaoxiao Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Jianyun Yao
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yunxue Guo
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Baiyuan Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yangmei Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Sciences, Xiamen University, Xiamen, China.,Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, China
| | - Xiaoxue Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
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12
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Diversity and bioprospective potential (cold-active enzymes) of cultivable marine bacteria from the subarctic glacial Fjord, Kongsfjorden. Curr Microbiol 2014; 68:233-8. [PMID: 24121613 DOI: 10.1007/s00284-013-0467-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 09/17/2013] [Indexed: 10/26/2022]
Abstract
The diversity and abundance of culturable bacteria in Kongsfjorden water (15 stations) and sediments (12 stations) were studied. Viable numbers ranged between 105–106 CFU l−1 in water and 102–104 CFU g−1 in the sediments. A total of 291 and 43 bacterial isolates were retrieved from the water (KJF) and sediments (FS), respectively. Based on 16S rRNA gene sequence similarities, the KJF and FS isolates were grouped into 49 and 23 phylotypes, respectively. The KJF and FS phylotypes represented three phyla namely, Actinobacteria, Bacteroidetes, and Proteobacteria. At the genus level, Flavobacterium and Shewanella and at the species level, Pseudoaltermonas arctica and Colwellia psychrerythraea were dominant in the water and sediments, respectively. Most phylotypes were psychrotolerant with upper growth temperature limit of 25–37 °C and tolerated 0.3–2.5 M NaCl and pH values of 5.0–11.0. Majority of the phylotypes produced one or more of the extracellular hydrolytic enzymes amylase, lipase, caseinase, urease, gelatinase, and DNase at 4 and 18 °C, while none were chitinolytic. Few of the FS phylotypes exhibited extracellular activity only at 4 or 18 °C. Nine FS and 21 KJF isolates were pigmented. The predominant cellular fatty acids were unsaturated, branched, and modified fatty acids, which are unique to cold-adapted bacteria.
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13
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Singh AK, Sad K, Singh SK, Shivaji S. Regulation of gene expression at low temperature: role of cold-inducible promoters. Microbiology (Reading) 2014; 160:1291-1296. [DOI: 10.1099/mic.0.077594-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Psychrophilic micro-organisms are the most dominant flora in cold habitats. Their unique ability to survive and multiply at low temperatures (<5 °C) is based on their ability to modulate the rigidity of the membrane, to transcribe, to translate and to catalyse biochemical reactions at low temperature. A number of genes are known to be upregulated during growth at low temperature and cold-inducible promoters are known to regulate the expression of genes at low temperature. In this review, we attempted to compile promoter sequences of genes that are cold-inducible so as to identify similarities and to compare the distinct features of each type of promoter when microbes are grown in the cold.
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Affiliation(s)
| | - Kirti Sad
- Centre of Biotechnology (University of Allahabad), Allahabad, India
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14
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Sinha AK, Pavankumar TL, Kamisetty S, Mittal P, Ray MK. Replication arrest is a major threat to growth at low temperature in Antarctic Pseudomonas syringae Lz4W. Mol Microbiol 2013; 89:792-810. [PMID: 23815755 DOI: 10.1111/mmi.12315] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2013] [Indexed: 11/29/2022]
Abstract
Chromosomal damage was detected previously in the recBCD mutants of the Antarctic bacterium Pseudomonas syringae Lz4W, which accumulated linear chromosomal DNA leading to cell death and growth inhibition at 4°C. RecBCD protein generally repairs DNA double-strand breaks by RecA-dependent homologous recombination pathway. Here we show that ΔrecA mutant of P. syringae is not cold-sensitive. Significantly, inactivation of additional DNA repair genes ruvAB rescued the cold-sensitive phenotype of ΔrecBCD mutant. The ΔrecA and ΔruvAB mutants were UV-sensitive as expected. We propose that, at low temperature DNA replication encounters barriers leading to frequent replication fork (RF) arrest and fork reversal. RuvAB binds to the reversed RFs (RRFs) having Holliday junction-like structures and resolves them upon association with RuvC nuclease to cause linearization of the chromosome, a threat to cell survival. RecBCD prevents this by degrading the RRFs, and facilitates replication re-initiation. This model is consistent with our observation that low temperature-induced DNA lesions do not evoke SOS response in P. syringae. Additional studies show that two other repair genes, radA (encoding a RecA paralogue) and recF are not involved in providing cold resistance to the Antarctic bacterium.
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Affiliation(s)
- Anurag K Sinha
- Centre for Cellular and Molecular Biology Council of Scientific and Industrial Research, Uppal Road, Hyderabad, 500007, India
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15
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Draft Genome Sequence of the Antarctic Psychrophilic Bacterium Pseudomonas syringae Strain Lz4W. GENOME ANNOUNCEMENTS 2013; 1:1/3/e00377-13. [PMID: 23788547 PMCID: PMC3707596 DOI: 10.1128/genomea.00377-13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The psychrophilic bacterium Pseudomonas syringae strain Lz4W was isolated from soil samples from Antarctica to decipher the mechanisms of low-temperature adaptation. We report here the 4.982-Mb draft genome sequence of P. syringae Lz4W. This sequence will provide insights into the genomic basis of the psychrophilicity of this bacterium.
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Importance of trmE for growth of the psychrophile Pseudomonas syringae at low temperatures. Appl Environ Microbiol 2009; 75:4419-26. [PMID: 19429554 DOI: 10.1128/aem.01523-08] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transposon mutagenesis of Pseudomonas syringae Lz4W, a psychrophilic bacterium capable of growing at temperatures between 2 and 30 degrees C, yielded 30 cold-sensitive mutants, and CSM1, one of these cold-sensitive mutants, was characterized. Growth of CSM1 was retarded when it was cultured at 4 degrees C but not when it was cultured at 22 degrees C and 28 degrees C compared to the growth of wild-type cells, indicating that CSM1 is a cold-sensitive mutant of P. syringae Lz4W. The mutated gene in CSM1 was identified as trmE (coding for tRNA modification GTPase), and evidence is provided that this gene is induced at low temperatures. Further, the cold-inducible nature of the trmE promoter was demonstrated. In addition, the transcription start site and the various regulatory elements of the trmE promoter, such as the -10 region, -35 region, UP element, cold box, and DEAD box, were identified, and the importance of these regulatory elements in promoter activity were confirmed. The importance of trmE in rapid adaptation to growth at low temperatures was further highlighted by plasmid-mediated complementation that alleviated the cold-sensitive phenotype of CSM1.
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The Exiguobacterium genus: biodiversity and biogeography. Extremophiles 2009; 13:541-55. [DOI: 10.1007/s00792-009-0243-5] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Accepted: 03/30/2009] [Indexed: 10/20/2022]
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Satapathy AK, Pavankumar TL, Bhattacharjya S, Sankaranarayanan R, Ray MK. ATPase activity of RecD is essential for growth of the Antarctic Pseudomonas syringae Lz4W at low temperature. FEBS J 2008; 275:1835-51. [PMID: 18336576 DOI: 10.1111/j.1742-4658.2008.06342.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
RecD is essential for growth at low temperature in the Antarctic psychrotrophic bacterium Pseudomonas syringae Lz4W. To examine the essential nature of its activity, we analyzed wild-type and mutant RecD proteins with substitutions of important residues in each of the seven conserved helicase motifs. The wild-type RecD displayed DNA-dependent ATPase and helicase activity in vitro, with the ability to unwind short DNA duplexes containing only 5' overhangs or forked ends. Five of the mutant proteins, K229Q (in motif I), D323N and E324Q (in motif II), Q354E (in motif III) and R660A (in motif VI) completely lost both ATPase and helicase activities. Three other mutants, T259A in motif Ia, R419A in motif IV and E633Q in motif V exhibited various degrees of reduction in ATPase activity, but had no helicase activity. While all RecD proteins had DNA-binding activity, the mutants of motifs IV and V displayed reduced binding, and the motif II mutant showed a higher degree of binding to ssDNA. Significantly, only RecD variants with in vitro ATPase activity could complement the cold-sensitive growth of a recD-inactivated strain of P. syringae at 4 degrees C. These results suggest that the requirement for RecD at lower temperatures lies in its ATP-hydrolyzing activity.
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Affiliation(s)
- Ajit K Satapathy
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, India
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Sahu B, Ray MK. Auxotrophy in natural isolate: minimal requirements for growth of the Antarctic psychrotrophic bacteriumPseudomonas syringae Lz4W. J Basic Microbiol 2008; 48:38-47. [DOI: 10.1002/jobm.200700185] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Survival of bacteria at low temperatures provokes scientific interest because of several reasons. Investigations in this area promise insight into one of the mysteries of life science - namely, how the machinery of life operates at extreme environments. Knowledge obtained from these studies is likely to be useful in controlling pathogenic bacteria, which survive and thrive in cold-stored food materials. The outcome of these studies may also help us to explore the possibilities of existence of life in distant frozen planets and their satellites.
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Hutchison ML, Walters LD, Mead GC, Howell M, Allen VM. An assessment of sampling methods and microbiological hygiene indicators for process verification in poultry slaughterhouses. J Food Prot 2006; 69:145-53. [PMID: 16416912 DOI: 10.4315/0362-028x-69.1.145] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Studies to determine the appropriateness of the use of populations of indicator bacteria on poultry carcasses for process verification were undertaken in commercial slaughterhouses. Samples were collected from neck skin by excision or from whole carcass rinses and were examined for a range of presumptive process hygiene indicator bacteria. Coefficients of variation were calculated for each bacterial indicator and were significantly lower in excised samples, indicating more reproducible bacterial recovery by this sampling method. Total viable counts of aerobic bacteria, Enterobacteriaceae, and Pseudomonas in samples collected by excision had the lowest coefficients of variation when compared with other indicators and were therefore used for further study. The uncertainties associated with the quantification of each bacterial indicator were calculated and were lowest overall for total viable counts of aerobic bacteria. In general, uncertainty was higher for lower bacterial numbers. Results of microbiological testing on pooled excised neck skin samples were not significantly different from the mean of individually analyzed samples. Bacterial numbers increased by 1 log unit when cultures were stored under chilled conditions typical of those used for transporting samples to external laboratories, but the increases were not significant for Pseudomonas and aerobic bacteria when storage time was less than 17 h. Weak relationships were identified between bacterial indicator numbers and duration of processing, although cleanliness of the processing environment diminished visibly during this time. In the plants visited for this study, there was a poor relationship between presumptive bacterial indicator numbers and process hygiene. Consequently, bacterial analyses for process verification purposes may be of limited value.
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Affiliation(s)
- M L Hutchison
- Research Division, DLS-Eurofins, Wergs Road, Wolverhampton, West Midlands WV6 8QT, UK.
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Regha K, Satapathy AK, Ray MK. RecD plays an essential function during growth at low temperature in the antarctic bacterium Pseudomonas syringae Lz4W. Genetics 2005; 170:1473-84. [PMID: 15956672 PMCID: PMC1449786 DOI: 10.1534/genetics.104.038943] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The Antarctic psychrotrophic bacterium Pseudomonas syringae Lz4W has been used as a model system to identify genes that are required for growth at low temperature. Transposon mutagenesis was carried out to isolate mutant(s) of the bacterium that are defective for growth at 4 degrees but normal at 22 degrees . In one such cold-sensitive mutant (CS1), the transposon-disrupted gene was identified to be a homolog of the recD gene of several bacteria. Trans-complementation and freshly targeted gene disruption studies reconfirmed that the inactivation of the recD gene leads to a cold-sensitive phenotype. We cloned, sequenced, and analyzed approximately 11.2 kbp of DNA from recD and its flanking region from the bacterium. recD was the last gene of a putative recCBD operon. The RecD ORF was 694 amino acids long and 40% identical (52% similar) to the Escherichia coli protein, and it could complement the E. coli recD mutation. The recD gene of E. coli, however, could not complement the cold-sensitive phenotype of the CS1 mutant. Interestingly, the CS1 strain showed greater sensitivity toward the DNA-damaging agents, mitomycin C and UV. The inactivation of recD in P. syringae also led to cell death and accumulation of DNA fragments of approximately 25-30 kbp in size at low temperature (4 degrees ). We propose that during growth at a very low temperature the Antarctic P. syringae is subjected to DNA damage, which requires direct participation of a unique RecD function. Additional results suggest that a truncated recD encoding the N-terminal segment of (1-576) amino acids is sufficient to support growth of P. syringae at low temperature.
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Affiliation(s)
- K Regha
- Centre for Cellular and Molecular Biology, Hyderabad 500007, India
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Purusharth RI, Klein F, Sulthana S, Jäger S, Jagannadham MV, Evguenieva-Hackenberg E, Ray MK, Klug G. Exoribonuclease R interacts with endoribonuclease E and an RNA helicase in the psychrotrophic bacterium Pseudomonas syringae Lz4W. J Biol Chem 2005; 280:14572-8. [PMID: 15705581 DOI: 10.1074/jbc.m413507200] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Endoribonuclease E, a key enzyme involved in RNA decay and processing in bacteria, organizes a protein complex called degradosome. In Escherichia coli, Rhodobacter capsulatus, and Streptomyces coelicolor, RNase E interacts with the phosphate-dependent exoribonuclease polynucleotide phosphorylase, DEAD-box helicase(s), and additional factors in an RNA-degrading complex. To characterize the degradosome of the psychrotrophic bacterium Pseudomonas syringae Lz4W, RNase E was enriched by cation exchange chromatography and fractionation in a glycerol density gradient. Most surprisingly, the hydrolytic exoribonuclease RNase R was found to co-purify with RNase E. Co-immunoprecipitation and Ni(2+)-affinity pull-down experiments confirmed the specific interaction between RNase R and RNase E. Additionally, the DEAD-box helicase RhlE was identified as part of this protein complex. Fractions comprising the three proteins showed RNase E and RNase R activity and efficiently degraded a synthetic stem-loop containing RNA in the presence of ATP. The unexpected association of RNase R with RNase E and RhlE in an RNA-degrading complex indicates that the cold-adapted P. syringae has a degradosome of novel structure. The identification of RNase R instead of polynucleotide phosphorylase in this complex underlines the importance of the interaction between endo- and exoribonucleases for the bacterial RNA metabolism. The physical association of RNase E with an exoribonuclease and an RNA helicase apparently is a common theme in the composition of bacterial RNA-degrading complexes.
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Nakashima N, Tamura T. Cell-free protein synthesis using cell extract of Pseudomonas fluorescens and CspA promoter. Biochem Biophys Res Commun 2004; 319:671-6. [PMID: 15178458 DOI: 10.1016/j.bbrc.2004.05.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2004] [Indexed: 10/26/2022]
Abstract
We have modified the cell-free coupled transcription/translation system of bacteria. The cell-free extract of Pseudomonas fluorescens was used for translation instead of Escherichia coli. In addition, transcription of the target gene was regulated by CspA promoter with endogenous RNA polymerase instead of by T7 promoter with exogenous T7 RNA polymerase. We could increase the yields of soluble proteins using different combinations of the S30 extract and the promoter and different temperatures for protein synthesis. Increasing the variety of synthesis systems allows production of large quantities of soluble proteins. In order to carry out efficient cell-free protein synthesis, versatile pCop-plasmids carrying CspA promoter were constructed and these plasmids were applicable to expression of recombinant proteins in E. coli cells.
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Affiliation(s)
- Nobutaka Nakashima
- Proteolysis and Protein Turnover Research Group, Research Institute of Genome-based Biofactory, National Institute of Advanced Industrial Science and Technology, Sapporo 062-8517, Japan.
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Cavicchioli R, Siddiqui KS, Andrews D, Sowers KR. Low-temperature extremophiles and their applications. Curr Opin Biotechnol 2002; 13:253-61. [PMID: 12180102 DOI: 10.1016/s0958-1669(02)00317-8] [Citation(s) in RCA: 289] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Psychrophilic (cold-adapted) organisms and their products have potential applications in a broad range of industrial, agricultural and medical processes. In order for growth to occur in low-temperature environments, all cellular components must adapt to the cold. This fact, in combination with the diversity of Archaea, Bacteria and Eucarya isolated from cold environments, highlights the breadth and type of biological products and processes that might be exploited for biotechnology. Relative to this undisputed potential, psychrophiles and their products are under-utilised in biotechnology; however, recent advances, particularly with cold-active enzymes, herald rapid growth for this burgeoning field.
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Affiliation(s)
- Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, UNSW 2052, Australia.
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Janiyani KL, Ray MK. Cloning, sequencing, and expression of the cold-inducible hutU gene from the antarctic psychrotrophic bacterium Pseudomonas syringae. Appl Environ Microbiol 2002; 68:1-10. [PMID: 11772602 PMCID: PMC126550 DOI: 10.1128/aem.68.1.1-10.2002] [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
A promoter-fusion study with a Tn 5-based promoter probe vector had earlier found that the hutU gene which encodes the enzyme urocanase for the histidine utilization pathway is upregulated at a lower temperature (4 degrees C) in the Antarctic psychrotrophic bacterium Pseudomonas syringae. To examine the characteristics of the urocanase gene and its promoter elements from the psychrotroph, the complete hutU and its upstream region from P. syringae were cloned, sequenced, and analyzed in the present study. Northern blot and primer extension analyses suggested that the hutU gene is inducible upon a downshift of temperature (22 to 4 degrees C) and that there is more than one transcription initiation site. One of the initiation sites was specific to the cells grown at 4 degrees C, which was different from the common initiation sites observed at both 4 and 22 degrees C. Although no typical promoter consensus sequences were observed in the flanking region of the transcription initiation sites, there was a characteristic CAAAA sequence at the -10 position of the promoters. Additionally, the location of the transcription and translation initiation sites suggested that the hutU mRNA contains a long 5'-untranslated region, a characteristic feature of many cold-inducible genes of mesophilic bacteria. A comparison of deduced amino acid sequences of urocanase from various bacteria, including the mesophilic and psychrotrophic Pseudomonas spp., suggests that there is a high degree of similarity between the enzymes. The enzyme sequence contains a signature motif (GXGX(2)GX(10)G) of the Rossmann fold for dinucleotide (NAD(+)) binding and two conserved cysteine residues in and around the active site. The psychrotrophic enzyme, however, has an extended N-terminal end.
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Sheridan PP, Panasik N, Coombs JM, Brenchley JE. Approaches for deciphering the structural basis of low temperature enzyme activity. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1543:417-433. [PMID: 11150617 DOI: 10.1016/s0167-4838(00)00237-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An increasing number of enzymes active at low temperature are being studied to help determine the structural features important for cold-activity. This review examines the diversity of prokaryotic cold-active enzymes and the features proposed to account for low temperature activity. We then consider the difficulty of identifying the key structural features needed for cold-activity and the need to compare enzymes having different temperature optima from phylogenetically related organisms to determine features responsible for low temperature activity. In addition to studying naturally occurring enzymes, directed evolution experiments are discussed as methods for examining the proposed mechanisms influencing the thermal dependence of activity.
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Affiliation(s)
- P P Sheridan
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, 16802, University Park, PA, USA.
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