title: Experimental evolution of enhanced growth by Bacillus subtilis at low atmospheric pressure: genomic changes revealed by whole-genome sequencing.
abstract: Knowledge of how microorganisms respond and adapt to low-pressure (LP) environments is limited. Previously, Bacillus subtilis strain WN624 was grown at the near-inhibitory LP of 5 kPa for 1,000 generations and strain WN1106, which exhibited increased relative fitness at 5 kPa, was isolated. Genomic sequence differences between ancestral strain WN624 and LP-evolved strain WN1106 were identified using whole-genome sequencing. LP-evolved strain WN1106 carried amino acid-altering mutations in the coding sequences of only seven genes (fliI, parC, ytoI, bacD, resD, walK, and yvlD) and a single 9-nucleotide in-frame deletion in the rnjB gene that encodes RNase J2, a component of the RNA degradosome. By using a collection of frozen stocks of the LP-evolved culture taken at 50-generation intervals, it was determined that (i) the fitness increase at LP occurred rapidly, while (ii) mutation acquisition exhibited complex kinetics. A knockout mutant of rnjB was shown to increase the competitive fitness of B. subtilis at both LP and standard atmospheric pressure.
authors: Department of Microbiology and Cell Science, University of Florida, Merritt Island, Florida, USA.
authors: Samantha M
authors: SM
authors: Waters
authors: Department of Microbiology, Ohio State University, Columbus, Ohio, USA.
authors: Daniel R
authors: DR
authors: Zeigler
authors: Department of Microbiology and Cell Science, University of Florida, Merritt Island, Florida, USA WLN@ufl.edu.
authors: Wayne L
authors: WL
authors: Nicholson
mesh_terms: D000220:Adaptation, Biological; D001274:Atmospheric Pressure; D001412:Bacillus subtilis / Q000254:growth & development*; D004252:DNA Mutational Analysis; D019143:Evolution, Molecular; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D020125:Mutation, Missense; D017354:Point Mutation; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion