Continuous-culture studies of synthesis and regulation of extracellular beta(1-3) glucanase and protease enzymes from Oerskovia xanthineolytica

This article describes the synthesis and regulation of beta(1-3)glucanase and protease enzymes from the cell lytic system of Oerskovia xanthineolytica LL-G109 in continuous culture using different concentrations of carbon source (glucose) and inducer (glucan). These two enzyme activities are the main components of a lytic system capable of lysing and disrupting whole yeast cells; it is subject to catabolite repression by glucose and is induced by yeast glucan. Peaks of beta(1-3)glucanase and protease activity are obtained at dilution rates of between 0.05 and 0.15 h(-1). The glucanase-protease ratio is very high compared to other strains. At dilution rates above 0.15 h(-1) all activities are similar to those obtained in batch culture. The lytic enzyme system appears to contain several beta(1-3)glucanase enzymes. In continuous culture both productivity and enzyme concentrations are greatly in creased when compared to batch culture, 11- and 4.4-fold, respectively.