A new multi-stress resistant Wickerhamomyces anomalus: isolation, identification and bioethanol fermentation potential

Sustainable bio-renewable energy source is a need of an hour to meet the rising global energy demands. Efficient conversion of fermentable sugars by yeast into bioethanol from lingo-cellulosic biomass is one of the most important attribute. In order to get temperature and ethanol tolerant yeast strain, one hundred and seventy one soil samples were collected from adjacent areas of various sugar mills located in Punjab, Pakistan. Fifty six yeast strains were isolated and primarily screened for bioethanol production. Maximum bioethanol producing (3.07 g/L) yeast strain IHZ-26 was identified by sequencing of 18S rRNA ITS region and identified as a new strain of Wickerhamomyces anomalus which was assigned GenBank accession number KT883963. This strain demonstrated substantial tolerance to ethanol (25%) and temperature (50°C) and have the ability to significantly ferment several sugars i.e. glucose, fructose, mannose, maltose, xylose and lactose. To the best of our knowledge, this is first report of multi stress tolerant Wickerhamomyces anomalus from Pakistan. This yeast with these distinct characteristics can be employed in bioethanol industry for more viable and economical process.

Keywords: Thermotolerant, Yeast, Biofuel, Stress, Bioenergy, Ethanoltolerant.