Genome shuffling to improve thermotolerance, ethanol tolerance and ethanol productivity of Saccharomyces cerevisiae.
Genome shuffling is a powerful strategy for rapid engineering of microbial strains for desirable industrial phenotypes. Here we improved the thermotolerance and ethanol tolerance of an industrial yeast strain SM-3 by genome shuffling while simultaneously enhancing the ethanol productivity. The starting population was generated by protoplast ultraviolet irradiation and then subjected for the recursive protoplast fusion. The positive colonies from the library, created by fusing the inactivated protoplasts were screened for growth at 35, 40, 45, 50 and 55 degrees C on YPD-agar plates containing different concentrations of ethanol. Characterization of all mutants and wild-type strain in the shake-flask indicated the compatibility of three phenotypes of thermotolerance, ethanol tolerance and ethanol yields enhancement. After three rounds of genome shuffling, the best performing strain, F34, which could grow on plate cultures up to 55 degrees C, was obtained. It was found capable of completely utilizing 20% (w/v) glucose at 45-48 degrees C, producing 9.95% (w/v) ethanol, and tolerating 25% (v/v) ethanol stress.
Shi
Dong-jian
DJ
Laboratory of Food Biotechnology, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, 300457, Tianjin, People's Republic of China.
Wang
Chang-lu
CL
Wang
Kui-ming
KM
D032621:DNA Shuffling; D004351:Drug Resistance; D000431:Ethanol / Q000378:metabolism*; D016681:Genome, Fungal; D006358:Hot Temperature; D007218:Industrial Microbiology; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*
D000431:Ethanol