Lychee-Derived, Thermotolerant Yeasts for Second-Generation Bioethanol Production

Thermotolerant yeasts are widely considered to be alternative strains traditional for bioethanol production at high temperatures. In this study, thirty-two isolated from lychees were screened thermotolerance, and seven selected isolates identified as Candida tropicalis (isolates H8, H19, H23), Meyerozyma guilliermondii H1 H12) Saccharomyces cerevisiae H10 H18). They tolerated up 45 °C, 12% (v/v) ethanol concentration, 10 g/L acetic acid, 5 furfural, respectively, produced 47.96 70.18 of 160 glucose 40 °C during 48 h fermentation. Among the evaluated yeasts, M. showed great potential second-generation fermentation with its ability ferment xylose arabinose. Under optimal conditions resulting a Plackett Burman design Box Behnken design, highest concentration 11.12 was substrate-based sugarcane bagasse hydrolysate (non-detoxified hydrolysate) by H1. These findings suggested that newly thermotolerant yeast is good candidate agricultural wastes.