OCTYL GLUCOSIDE INHIBITS [C-14] DHP MINERALIZATION WHEREAS PEROXIDASE-ACTIVITY IS STIMULATED IN PHANEROCHAETE-CHRYSOSPORIUM

Octyl glucoside stimulated peroxidase formation in Phanerochaete chrys osporium ME-446 cultivated in cellulose-based media. Addition of 0.1% of the nonionic surfactant resulted in a ninefold (143 U/L) and sixfol d (119 U/L) increase in LiP formation under conditions of N limitation and N excess, respectively. Octyl glucoside also stimulated MnP forma tion, but to a lesser extent than observed with LiP. The cellobiose-ox idizing enzymes (cellobiose dehydrogenase and cellobiose:quinone oxido reductase) were stimulated by octyl glucoside when used at a concentra tion of up to 0.05%, but higher concentrations gave values similar to those for the controls. Little proteolytic activity was detected in th e presence of the surfactant. In general, activities of the enzymes st udied were of the same order as those seen using Tween-80. In contrast with Tween-80, octyl glucoside markedly inhibited [C-14]DHP mineraliz ation. Attempts to account for the observed inhibition of synthetic li gnin degradation by P. chrysosporium in the presence of octyl glucosid e are discussed.