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Lee HS, Lee HJ, Kim B, Kim SH, Cho DH, Jung HJ, Bhatia SK, Choi KY, Kim W, Lee J, Lee SH, Yang YH. Inhibition of Cyclopropane Fatty Acid Synthesis in the Membrane of Halophilic Halomonas socia CKY01 by Kanamycin. BIOTECHNOL BIOPROC E 2022. [DOI: 10.1007/s12257-022-0086-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Choi TR, Song HS, Han YH, Park YL, Park JY, Yang SY, Bhatia SK, Gurav R, Kim HJ, Lee YK, Choi KY, Yang YH. Enhanced tolerance to inhibitors of Escherichia coli by heterologous expression of cyclopropane-fatty acid-acyl-phospholipid synthase (cfa) from Halomonas socia. Bioprocess Biosyst Eng 2020; 43:909-918. [PMID: 31989256 DOI: 10.1007/s00449-020-02287-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 01/11/2020] [Indexed: 02/05/2023]
Abstract
Bacteria have evolved a defense system to resist external stressors, such as heat, pH, and salt, so as to facilitate survival in changing or harsh environments. However, the specific mechanisms by which bacteria respond to such environmental changes are not completely elucidated. Here, we used halotolerant bacteria as a model to understand the mechanism conferring high tolerance to NaCl. We screened for genes related to halotolerance in Halomonas socia, which can provide guidance for practical application. Phospholipid fatty acid analysis showed that H. socia cultured under high osmotic pressure produced a high portion of cyclopropane fatty acid derivatives, encoded by the cyclopropane-fatty acid-acyl phospholipid synthase gene (cfa). Therefore, H. socia cfa was cloned and introduced into Escherichia coli for expression. The cfa-overexpressing E. coli strain showed better growth, compared with the control strain under normal cultivation condition as well as under osmotic pressure (> 3% salinity). Moreover, the cfa-overexpressing E. coli strain showed 1.58-, 1.78-, 3.3-, and 2.19-fold higher growth than the control strain in the presence of the inhibitors furfural, 4-hydroxybenzaldehyde, vanillin, and acetate from lignocellulosic biomass pretreatment, respectively. From a practical application perspective, cfa was co-expressed in E. coli with the polyhydroxyalkanoate (PHA) synthetic operon of Ralstonia eutropha using synthetic and biosugar media, resulting in a 1.5-fold higher in PHA production than that of the control strain. Overall, this study demonstrates the potential of the cfa gene to boost cell growth and production even in heterologous strains under stress conditions.
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Affiliation(s)
- Tae-Rim Choi
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea
| | - Hun-Suk Song
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea
| | - Yeong-Hoon Han
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea
| | - Ye-Lim Park
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea
| | - Jun Young Park
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea
| | - Su-Yeon Yang
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea
| | - Shashi Kant Bhatia
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea.,Institute for Ubiquitous Information Technology and Applications, Konkuk University, Seoul, 143-701, South Korea
| | - Ranjit Gurav
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea
| | - Hyun Joong Kim
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea
| | - Yoo Kyung Lee
- Division of Life Sciences, Korea Polar Research Institute, Incheon, Republic of Korea
| | - Kwon Young Choi
- Department of Environmental Engineering, College of Engineering, Ajou University, Suwon, Gyeonggi-do, South Korea
| | - Yung-Hun Yang
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea. .,Institute for Ubiquitous Information Technology and Applications, Konkuk University, Seoul, 143-701, South Korea.
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Nichols DS, Olley J, Garda H, Brenner RR, McMeekin TA. Effect of temperature and salinity stress on growth and lipid composition of Shewanella gelidimarina. Appl Environ Microbiol 2000; 66:2422-9. [PMID: 10831420 PMCID: PMC110550 DOI: 10.1128/aem.66.6.2422-2429.2000] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/1999] [Accepted: 03/22/2000] [Indexed: 11/20/2022] Open
Abstract
The maximum growth temperature, the optimal growth temperature, and the estimated normal physiological range for growth of Shewanella gelidimarina are functions of water activity (a(w)), which can be manipulated by changing the concentration of sodium chloride. The growth temperatures at the boundaries of the normal physiological range for growth were characterized by increased variability in fatty acid composition. Under hyper- and hypoosmotic stress conditions at an a(w) of 0.993 (1.0% [wt/vol] NaCl) and at an a(w) of 0.977 (4.0% [wt/vol] NaCl) the proportion of certain fatty acids (monounsaturated and branched-chain fatty acids) was highly regulated and was inversely related to the growth rate over the entire temperature range. The physical states of lipids extracted from samples grown at stressful a(w) values at the boundaries of the normal physiological range exhibited no abrupt gel-liquid phase transitions when the lipids were analyzed as liposomes. Lipid packing and adaptational fatty acid composition responses are clearly influenced by differences in the temperature-salinity regime, which are reflected in overall cell function characteristics, such as the growth rate and the normal physiological range for growth.
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Affiliation(s)
- D S Nichols
- School of Agricultural Science, University of Tasmania, Hobart, Tasmania 7001, Australia.
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Abstract
Bacteria can survive dramatic osmotic shifts. Osmoregulatory responses mitigate the passive adjustments in cell structure and the growth inhibition that may ensue. The levels of certain cytoplasmic solutes rise and fall in response to increases and decreases, respectively, in extracellular osmolality. Certain organic compounds are favored over ions as osmoregulatory solutes, although K+ fluxes are intrinsic to the osmoregulatory response for at least some organisms. Osmosensors must undergo transitions between "off" and "on" conformations in response to changes in extracellular water activity (direct osmosensing) or resulting changes in cell structure (indirect osmosensing). Those located in the cytoplasmic membranes and nucleoids of bacteria are positioned for indirect osmosensing. Cytoplasmic membrane-based osmosensors may detect changes in the periplasmic and/or cytoplasmic solvent by experiencing changes in preferential interactions with particular solvent constituents, cosolvent-induced hydration changes, and/or macromolecular crowding. Alternatively, the membrane may act as an antenna and osmosensors may detect changes in membrane structure. Cosolvents may modulate intrinsic biomembrane strain and/or topologically closed membrane systems may experience changes in mechanical strain in response to imposed osmotic shifts. The osmosensory mechanisms controlling membrane-based K+ transporters, transcriptional regulators, osmoprotectant transporters, and mechanosensitive channels intrinsic to the cytoplasmic membrane of Escherichia coli are under intensive investigation. The osmoprotectant transporter ProP and channel MscL act as osmosensors after purification and reconstitution in proteoliposomes. Evidence that sensor kinase KdpD receives multiple sensory inputs is consistent with the effects of K+ fluxes on nucleoid structure, cellular energetics, cytoplasmic ionic strength, and ion composition as well as on cytoplasmic osmolality. Thus, osmoregulatory responses accommodate and exploit the effects of individual cosolvents on cell structure and function as well as the collective contribution of cosolvents to intracellular osmolality.
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Affiliation(s)
- J M Wood
- Department of Microbiology and Guelph-Waterloo Centre for Graduate Work in Chemistry, University of Guelph, Guelph, Ontario, Canada N1G
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Abstract
The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mechanisms of adjustment of the intracellular environments and the properties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate halophiles, opening the way toward an understanding of haloadaptation at the molecular level. The new information obtained is also expected to contribute to the development of novel biotechnological uses for these organisms.
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Affiliation(s)
- A Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
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Loffeld B, Keweloh H. cis/trans isomerization of unsaturated fatty acids as possible control mechanism of membrane fluidity in Pseudomonas putida P8. Lipids 1996; 31:811-5. [PMID: 8869883 DOI: 10.1007/bf02522976] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Exponentially growing cells of Pseudomonas putida had an increased ratio of saturated to unsaturated fatty acids in response to increased growth temperatures. Resting cells in which fatty acid biosynthesis was stopped reacted to a thermal increase by converting cis-monounsaturated fatty acids to trans isomers. cis/trans Isomerization of up to 60% of the unsaturated fatty acids was also activated by alcohols of different chain length. Their effective concentrations apparently depended on the lipophilic character of the alcohols. Also, a salt shock caused by the addition of NaCl resulted in the production of trans fatty acids. However, cells that were adapted to growth media of high osmolarity synthesized cyclopropane fatty acids instead of trans fatty acids. Activity of cis/trans-isomerase was dependent on the growth phase and was significantly higher during logarithmic growth than during the stationary phase. The results of this study agree with the hypothesis that the isomerization of cis into trans unsaturated fatty acids is an emergency action of cells of P. putida to adapt membrane fluidity to drastic changes of environmental conditions.
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Affiliation(s)
- B Loffeld
- Department of Microbiology, University of Muenster, Germany
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