Growth of thermotolerant Pichia kudriavzevii UniMAP 3-1 strain for ethanol production using xylose and glucose at different fermentation temperatures

Abstract

The applications of thermotolerant microorganisms in the production of lignocellulosic bioethanol is the key factor for successful simultaneous saccharification and fermentation process. Thus, this study aimed to isolate a thermotolerant yeast strain that was able to convert both glucose and xylose into ethanol. An analysis based on D1/D2 region of the large-subunit ribosomal DNA identified the isolated strain namely as Pichia kudriavzevii UniMAP 3-1. The growth of this newly isolated yeast was tested with fermentation temperature at 30 oC and 40°C on xylose and glucose. P. kudriavzevii UniMAP 3-1 was able to ferment xylose to ethanol at both 30 oC and 40 oC with a yield of 0.013 g/g and 0.019 g/g with concomitant xylitol yield of 0.24 g/g and 0.25 g/g, respectively. Fermentation of glucose to ethanol was also tested at 30 oC and 40 oC and the yields were 0.42 g/g and 0.41 g/g, respectively. The potential of this thermotolerant yeast to be used in high-temperature fermentation in both glucose and xylose are proven in this study.