Effect of temperature and pH onCandida blankii in chemostat culture

Abstract

The growth characteristics ofCandida blankii as a function of temperature and pH in a simulated bagasse hemicellulose hydrolysate were determined in chemostat culture. The highest maximum specific growth rate of 0.44h(-1) was reached at 38°C and at pH 5.5, with a sharp decrease in growth rate on either side of this temperature. Growth occurred at 46°C but not at 48°C. The protein and cell yields varied little below 40°C and the respective values were 0.22 and 0.5 g/g at 38°C. At the lower pH values, a severe linear decrease in cell and protein yields occurred, whereas a small increase in these yields at decreasing pH values was found when acetic acid was omitted from the medium. In the presence of acetic acid, a very sharp decrease in the growth rate at pH values below pH 4.5 was noted, despite the very low residual acetic acid concentrations, of less than 50 mg/l, in the culture.

Fermentation of xylose into ethanol by a new fungus strain Pestalotiopsis sp. XE-1

“…Temperature and initial pH were the most important process parameters. They aVected the rates of both microbial cell growth and product formation [15,25]. XE-1 grew best and produced maximum ethanol from xylose at pH 6.5, 30°C and under the semi-aerobic condition.…”