Effects of agitation and aeration on Production of Hexokinase

A batch culture of saccharomyces cerevisiae for the production of hexoki-nase Was carried out in a 5-L fermentor containing 3 L of culture medium, Which was inoculated with cell suspension (about 0.7 g/L), and left fermenting At 35°C and ph 4.0. The aeration and agitation were adjusted to attain k_La values of 15, 60, 135, and 230 h^-1. The highest hexokinase productivity (754.6 U/[L?h]) and substrate-cell conversion yield (0.21 g/g) occurred for a k_La of 60 h¹. Moreover, the formation of hexokinase and cell growth are Coupled events, which is in accordance with the constitutive character of this Enzyme. Hexokinase formation for k_La >60 h^-1was not enhanced probably Owing to saturation of the respiratory pathway by oxygen.