Isolation Thermo-Tolerant and Ethanol-Tolerant Yeast from Local Vegetables and Their Potential as Bioethanol Producers
Mochamad Nurcholis, Ricky Kurniawan, Joni Kusnadi, Jaya Mahar Maligan*

Agricultural Product Technology Department, Agricultural Technology Faculty Brawijaya University of Malang
Jl. Veteran, Malang 65145
*Correspondence author, Email: maharajay[at]gmail.com

Abstract

Bioethanol can be obtained from fermented ingredients containing starch, sucrose, glucose, or fructose. Yeast acts as a bioethanol producer, has limited tolerance to ethanol, and also cannot withstand temperatures above 40oC. Therefore, yeast is needed because it has a heat resistance and high ethanol in bioethanol fermentation. This research is a descriptive study conducted in three stages. The first stage is to isolate yeast from eggplant, cabbage, potatoes, mustard greens, bitter melon, squash, green beans, kale, and celery. The second stage is to test tolerant of the temperature and ethanol from yeast that has been obtained. The third stage is to test the productivity of ethanol in yeast. The results showed isolates S17c, S17d, S17a, S17b, S09, S12, S13a, S13b, S17e, S18a, and S18b can grow at 45oC. While in the ethanol tolerance test found that isolates S17c, S17d, S17b, S17a, S09, S12, S13a, S13b, S18a, and S18b can grow on YPGA media with 15% ethanol content. For the ability in ethanol production, isolate code S17d has the highest ethanol which produce 3.13% ethanol in 24th-hour fermentation.

Keywords: Bioethanol, isolation of yeast, yeast, high ethanol, high temperature

Topic: INDUSTRIAL BIOTECHNOLOGY AND BIOPROCESSING