Screening and characterization of potential bioethanol production yeast from tropical fruits

Abstract

This study aims to separate and characterise indigenous yeast (IY) from tropical fruit waste. The techniques include isolating and characterising yeast from different kinds of fruit waste, testing yeast for ethanol and glucose tolerance, and producing bioethanol in vitro. Using a microscope and visual inspection, the yeast’s morphological identification is done. Using a spectrophotometer to measure optical density, the tolerance tests for glucose and ethanol are used to select yeast biochemically. With the Gas Chromatography-Flame Ionisation Detector (GC-FID), one can measure the amount of ethanol present. Yeast was isolated using selective media to yield six isolates: code A1 from grapes, codes NG1, NG2 from jackfruit, and codes N1, N2, and N3 from pineapple; mango produced no results. Three isolates with the codes A1, NG1, and NG2 were chosen based on test results for resistance to glucose and ethanol. The Saccharomyces cerevisae bioethanol production test yielded 6.60%, 3.30%, 4.5%, and.4.85% of ethanol for the yeast species coded A1, NG1, and NG2, respectively, in terms of ethanol. According to the study’s findings, yeast bearing the NG2 code may be used in the fermentation process to produce bioethanol.