Engineering cellular robustness of microbes by introducing the GroESL chaperonins from extremophilic bacteria
•A novel and universal method for cellular robustness engineering by introducing groESL from extremophilic bacteria was proposed and confirmed.•Thermo- and ethanol-tolerances of Escherichia coli cells were improved by introduction of groESL from Pseudomonas putida.•Clostridium acetobutylicum overexpressing groESL from Thermoanaerobacter tengcongensis showed significantly improved corn-cob-hydrolysates tolerant and utilization capacities.
The cellular robustness is a big concern for efficient microbial production of biofuels and biochemicals. In this study, the groESL genes from extremophilic bacteria were found to serve as transplantable stress–response elements to improve diverse types of stress-tolerances of other microbes. By overexpressing the groESL from the solvent-tolerant Pseudomonas putida in Escherichia coli, its thermo-tolerance and ethanol-tolerance were significantly increased. Meanwhile, the groESL from the thermophilic Thermoanaerobacter tengcongensis endowed Clostridium acetobutylicum with improved corn cob hydrolysates (CCH)-tolerance as well as elevated butanol productivity. The chaperonins GroESL have been widely considered as cellular stress–response proteins and overexpression of native groESL has been proven to improve cellular tolerances facing various stresses. Here we found that the groESL genes from extremophilic bacteria were superior to the native ones, possibly because they have adapted to the environmental stresses during long-term natural evolution. Moreover, our results also revealed that different extreme groESL genes performed quite different in different microbes. Thus the relation and compatibility between the extremophiles and the host must be considered for selection of the proper groESL for engineering microbial robustness.
Journal: Journal of Biotechnology - Volume 178, 20 May 2014, Pages 38–40