The selection and the Growth Condition Optimization of Ethanol‐Producing Microbes Isolated from Ragi Tapai

Ethanol is a biofuel produced from renewable resources, which potentially plays an important role in solving future fuel problems. This study aimed to select the highest ethanol-producing isolate candidates obtained previously isolated ragi and cassava tapai. The selection process was conducted 2 stages, namely: 1) Selection of seven using PYG media containing peptone, yeast extract, glucose at 0.75%, 15%, respectively followed by: 2) Optimization growth conditions isolate, various temperatures 27, 30, 33, 35, 37, 40°C with combination pH 3.5, 4.5, 5.5, 6.5. experimental results showed that R5I3 performance yielded approximately 4.69±0.25% (v/v). Following temperature optimization fermentation processes, optimum were 35°C where ethanol increased 8.63 ± 0.04% With these results, this new strain has potential be used bioethanol production processes other industrial applications.