2.2 Studying of yeast growth curve
Each yeast isolate was cultivated in YM broth (pH4.5) and then incubated in a rotary shaker with shaking speed of 150 rpm at 45 C for 48 hrs. Yeast growth curves were studied by measured the optical density (OD660) of the culture every 2 hr using spectrophotometer. Successful cultures were collected and screened further for their ethanol production efficiency at high temperature.