Open AccessDynamic cell responses in Thermoanaerobacterium sp. under hyperosmotic stress
Author(s) -
Muzi Zhu,
Wudi Fan,
Yaping Cha,
Xiaofeng Yang,
Zhicheng Lai,
Shuang Li,
X. Wang
Publication year - 2017
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-017-10514-8
Subject(s) - fermentation , transcriptome , strain (injury) , chemistry , osmotic shock , lysis , mutant , ethanol , substrate (aquarium) , intracellular , biochemistry , yield (engineering) , ethanol fuel , biology , gene , gene expression , materials science , ecology , anatomy , metallurgy
As a nongenetic engineering technique, adaptive evolution is an effective and easy-to-operate approach to strain improvement. In this work, a commercial Thermoanaerobacterium aotearoense SCUT27 /Δldh -G58 was successfully isolated via sequential batch fermentation with step-increased carbon concentrations. Mutants were isolated under selective high osmotic pressures for 58 passages. The evolved isolate rapidly catabolized sugars at high concentrations and subsequently produced ethanol with good yield. A 1.6-fold improvement of ethanol production was achieved in a medium containing 120 g/L of carbon substrate using the evolved strain, compared to the start strain. The analysis of transcriptome and intracellular solute pools suggested that the adaptive evolution altered the synthesis of some compatible solutes and activated the DNA repair system in the two Thermoanaerobacterium sp. evolved strains. Overall, the results indicated the potential of adaptive evolution as a simple and effective tool for the modification and optimization of industrial microorganisms.