Isolation, screening and identification of ethanol producing yeasts from Ethiopian fermented beverages

Dagnew Bitew; Anteneh Tesfaye; Berhanu Andualem

doi:10.1016/j.btre.2023.e00815

Isolation, screening and identification of ethanol producing yeasts from Ethiopian fermented beverages

Biotechnol Rep (Amst). 2023 Oct 4:40:e00815. doi: 10.1016/j.btre.2023.e00815. eCollection 2023 Dec.

Authors

Dagnew Bitew^{1

2}, Anteneh Tesfaye^{3

4}, Berhanu Andualem⁴

Affiliations

¹ Department of Biology, Mizan-Tepi University, P. BOX: 260, Ethiopia.
² Institute of Biotechnology, University of Gondar, P.BOX: 196, Ethiopia.
³ Institute of Biotechnology, Addis Ababa University, P.BOX: 1176, Ethiopia.
⁴ BioTEI, Winnipeg, Manitoba, Canada.

Abstract

The growing demand for renewable energy sources such as bioethanol is facing a lack of efficient ethanologenic microbes. This study aimed to isolate and screen ethanologenic yeasts from Ethiopian fermented beverages. A progressive screening and selection approach was employed. Selected isolates were evaluated for bioethanol production using banana peel waste as substrate. A total of 102 isolates were obtained. Sixteen isolates were selected based on their tolerance to stress conditions and carbohydrate fermentation and assimilation capacity. Most found moderately tolerant to 10 %, but slightly tolerant at 15 and 20 % (v/v) ethanol concentration. They yield 15.3 to 20.1 g/L and 9.1 ± 0.6 to 12.9 ± 1.3 g/L ethanol from 2 % (w/v) glucose and 80 g/L banana peel, respectively. Molecular characterization identified them as Saccharomyces cerevisiae strains. Results demonstrate insight about their potential role in the ethanol industry. Optimization of the fermentation conditions is recommended.

Keywords: Banana peel; Bioethanol; Biomass; Renewable energy; S. cerevisiae.