Physiological and Metabolomic Analysis of Issatchenkia orientalis MTY1 With Multiple Tolerance for Cellulosic Bioethanol Production

摘要

> Yeast with multiple tolerance onto harsh conditions has a number of advantages for bioethanol production. In this study, an alcohol yeast of Issatchenkia orientalis MTY1 is isolated in a Korean winery and its multiple tolerance against high temperature and acidic conditions is characterized in microaerobic batch cultures and by metabolomic analysis. In a series of batch cultures using 100?g?L ?1 glucose, I. orientalis MTY1 possesses wider growth ranges at pH 2–8 and 30–45?°C than a conventional yeast of Saccharomyces cerevisiae D452‐2. Moreover, I. orientalis MTY1 showes higher cell growth and ethanol productivity in the presence of acetic acid or furfural than S. cerevisiae D452‐2. I. orientalis MTY1 produces 41.4?g?L ?1 ethanol with 1.5?g?L ?1 ?h ?1 productivity at 42?°C and pH 4.2 in the presence of 4?g?L ?1 acetic acid, whereas a thermo‐tolerant yeast of Kluyvermyces marxianus ATCC36907 does not grow. By metabolomics by GC‐TOF MS and statistical analysis of 125 metabolite peaks, it is revealed that the thermo‐tolerance of I. orientalis MTY1 might be ascribed to higher contents of unsaturated fatty acids, purines and pyrimidines than S. cerevisiae D452‐2. Conclusively, I. orientalis MTY1 could be a potent workhorse with multiple tolerance against harsh conditions considered in cellulosic bioethanol production.