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

Abstract

This article describes the synthesis and regulation of β(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 β(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 β(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.