title: High-temperature ethanol production using thermotolerant yeast newly isolated from Greater Mekong Subregion.
abstract: The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS) countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR) and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45°C and 13% (v/v), respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40°C and 43°C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37°C with an ethanol concentration of 72.69g/L, a productivity of 1.59g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ) at 40°C were achieved using the Box-Behnken experimental design (BBD). The maximal ethanol concentration obtained during fermentation was 89.32g/L, with a productivity of 2.48g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future.
authors.affiliation: Graduate School, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Atiya
authors.initials: A
authors.lastname: Techaparin
authors.affiliation: Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand; Fermentation Research Center for Value Added Agricultural Products (FerVAAP), Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Pornthap
authors.initials: P
authors.lastname: Thanonkeo
authors.affiliation: Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand; Fermentation Research Center for Value Added Agricultural Products (FerVAAP), Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address: kpreek@kku.ac.th.
authors.forename: Preekamol
authors.initials: P
authors.lastname: Klanrit
mesh_terms: D001210:Asia, Southeastern; D000431:Ethanol / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006358:Hot Temperature; D010843:Pichia / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D045868:Sorghum / Q000378:metabolism
chemical_list: D000431:Ethanol; D005947:Glucose
keywords: Box–Behnken experimental design; Ethanol production; Response surface method; Sweet sorghum juice (SSJ); Thermotolerant yeast