Key Metabolites and Mechanistic Changes for Salt Tolerance in an Experimentally Evolved Sulfate-Reducing Bacterium, Desulfovibrio vulgaris
- Univ. of Oklahoma, Norman, OK (United States). Inst. for Environmental Genomics, Dept. of Microbiology and Plant Biology
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Genomics and Systems Biology Division
- Univ. of Washington, Seattle, WA (United States). Dept. of Earth and Space Sciences
- Univ. of Missouri, Columbia, MO (United States). Dept. of Biochemistry and Molecular Microbiology and Immunology
- Univ. of Washington Bothell, Bothell, WA (United States). School of Science, Technology, Engineering and Mathematics
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Genomics and Systems Biology Division; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division
- Univ. of Oklahoma, Norman, OK (United States). Inst. for Environmental Genomics, Dept. of Microbiology and Plant Biology; Tsinghua Univ., Beijing (China). State Key Joint Lab. of Environment Simulation and Pollution Control, School of Environment
ABSTRACT. Rapid genetic and phenotypic adaptation of the sulfate-reducing bacteriumDesulfovibrio vulgarisHildenborough to salt stress was observed during experimental evolution. In order to identify key metabolites important for salt tolerance, a clone, ES10-5, which was isolated from population ES10 and allowed to experimentally evolve under salt stress for 5,000 generations, was analyzed and compared to clone ES9-11, which was isolated from population ES9 and had evolved under the same conditions for 1,200 generations. These two clones were chosen because they represented the best-adapted clones among six independently evolved populations. ES10-5 acquired new mutations in genes potentially involved in salt tolerance, in addition to the preexisting mutations and different mutations in the same genes as in ES9-11. Most basal abundance changes of metabolites and phospholipid fatty acids (PLFAs) were lower in ES10-5 than ES9-11, but an increase of glutamate and branched PLFA i17:1ω9c under high-salinity conditions was persistent. ES9-11 had decreased cell motility compared to the ancestor; in contrast, ES10-5 showed higher cell motility under both nonstress and high-salinity conditions. Both genotypes displayed better growth energy efficiencies than the ancestor under nonstress or high-salinity conditions. Consistently, ES10-5 did not display most of the basal transcriptional changes observed in ES9-11, but it showed increased expression of genes involved in glutamate biosynthesis, cation efflux, and energy metabolism under high salinity. These results demonstrated the role of glutamate as a key osmolyte and i17:1ω9c as the major PLFA for salt tolerance inD. vulgaris. The mechanistic changes in evolved genotypes suggested that growth energy efficiency might be a key factor for selection. IMPORTANCE. High salinity (e.g., elevated NaCl) is a stressor that affects many organisms. Salt tolerance, a complex trait involving multiple cellular pathways, is attractive for experimental evolutionary studies.Desulfovibrio vulgarisHildenborough is a model sulfate-reducing bacterium (SRB) that is important in biogeochemical cycling of sulfur, carbon, and nitrogen, potentially for bio-corrosion, and for bioremediation of toxic heavy metals and radionuclides. The coexistence of SRB and high salinity in natural habitats and heavy metal-contaminated field sites laid the foundation for the study of salt adaptation ofD. vulgarisHildenborough with experimental evolution. Here in this paper, we analyzed a clone that evolved under salt stress for 5,000 generations and compared it to a clone evolved under the same condition for 1,200 generations. The results indicated the key roles of glutamate for osmoprotection and of i17:1ω9c for increasing membrane fluidity during salt adaptation. The findings provide valuable insights about the salt adaptation mechanism changes during long-term experimental evolution.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- AC02-05CH11231
- OSTI ID:
- 1432221
- Journal Information:
- mBio (Online), Vol. 8, Issue 6; ISSN 2150-7511
- Publisher:
- American Society for MicrobiologyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Differential Production of Pigments by Halophilic Bacteria Under the Effect of Salt and Evaluation of Their Antioxidant Activity
|
journal | July 2019 |
Adaptation of Desulfovibrio alaskensis G20 to perchlorate, a specific inhibitor of sulfate reduction
|
journal | March 2019 |
Growth of an anaerobic sulfate-reducing bacterium sustained by oxygen respiratory energy conservation after O 2 -driven experimental evolution: O 2 -driven experimental evolution of Desulfovibrio
|
journal | December 2018 |
Similar Records
Rapid selective sweep of pre-existing polymorphisms and slow fixation of new mutations in experimental evolution of Desulfovibrio vulgaris
Rapid selective sweep of pre-existing polymorphisms and slow fixation of new mutations in experimental evolution of Desulfovibrio vulgaris