High temperature alcoholic fermentation of orange peel by the newly isolated thermotolerant Pichia kudriavzevii KVMP10.

UNLABELLED: This work explores the potential for the development of orange peel based ethanol bioprocesses through isolation of the thermotolerant Pichia kudriavzevii KVMP10. A model solution of hydrolysed Valencia orange peel was employed to determine the ethanologenic potential of the yeast, which was maximized at 42°C producing 54 g l(-1) of ethanol. The effect of orange peel oil on bioethanol formation was investigated at 30 and 42°C confirming that the minimum inhibitory peel oil content was 0·01% (v/v). Pichia kudriavzevii KVMP10 demonstrated significant technological advantages for the production of sustainable bioenergy, such as utilization of both hexoses (glucose, sucrose, fructose and galactose) and pentoses (xylose) at high temperatures, exemplifying its great potential for application in orange peel based biorefineries for ethanol production. SIGNIFICANCE AND IMPACT OF THE STUDY: Citrus peel waste is one of the most underutilized and geographically diverse residues in the planet. In attempt to develop a citrus peel based biorefinery we report here the isolation of a yeast which exhibited favourable technological characteristics for the production of ethanol through utilization of the specific food waste. Pichia kudriavzevii KVMP10 was highly thermotolerant and utilized both hexoses and pentoses for ethanol production, which was achieved at elevated rates, highlighting its great potential for application in ethanol production processes from citrus peel.