Effect of kLa on the production of glucose 6-phosphate dehydrogenase from Saccharomyces cerevisiae grown by fermentation process

In a 5-L fermentor (NBS-MF 105), Saccharomyces cerevisiae (0.7 g/L) was inoculated into a liquid medium (pH 4.0) containing 17 g/L of glucose, 2.55 g/L of yeast extract, 4.25 g/L of peptone, 2.04 g/L of Na(2)HPO(4)(.)12H(2)O, 4.34 g/L of (NH4)(2)SO4 and 0.064 g/L of MgSO(4)(.)7H(2)O and aerobically cultivated at 35 C for 22 h. Agitation and aeration were adjusted to attain initial k(L)a values of 15, 60, 135, and 230 h(-1). The glucose 6-phosphate dehydrogenase (G6PDH) productivity (Pr-G6PDH) obtained for kLa values of 15, 60, 135, and 230 h(-1) was 10.6, 31.8, 30.3, and 23.3 U/([L(.)h]), respectively, whereas the cell productivity (Pr-x) for the same k(L)a values were 0.24, 0.69, 0.69, and 0.49 g/[L(.)h], respectively. Thus, both events are coupled and depend on the dissolved oxygen in the medium.