Some fermentation parameters influencing single cell protein production from cassava starch by Schwanniomyces occidentalis TISTR

บทคัดย่อ

The yeast Schwanniomyces occidentalis TISTR5555 was cultured in the modified YM medium containingcassava starch as a sole carbon source. The optimum cultural conditions for growth and protein production wereinvestigated. In a shake-flask culture at 30 ÌC, the maximum growth and protein concentration were obtained whenyeast cells were grown in the culture medium consisting of (w/v) 4% cassava starch, 0.5 % NH4NO3 and 0.5 %yeast extract. The optimum initial pH of the growth medium was 5.5. In the experiment conducted in 5 and 10-lbioreactor, 2.43 and 2.84 g/l of protein were obtained, respectively, under optimum growth conditions. Chemicalcomposition analysis of the yeast biomass produced in the bioreactor revealed 43.87% dry weight of total protein.The highest amino acid and fatty acid were glutamic acid (3.65 g/ 100 g protein) and oleic acid (1.44 g/ 100 g dryweight), respectively.