Increased endoplasmic reticulum content of Phanerochaete chrysosporium INA-12 by inositol phospholipid precursor in relation to peroxidase excretion

Summary Haem protein excretion (i.e., lignin and manganese-dependent peroxidases) by Phanerochaete chrysosporium INA-12 was improved in response to an exogenous supply of phospholipid components (inositol and linoleic acid) as well as phosphatidylinositol (PI). Maximal enzyme productions were 46.3 and 21.1 nkat · ml^–1, respectively, in inositol cultures after 3 days incubation. Cellular compartment determination by marker enzymes revealed that the enhancement of protein excretion with inositol was correlated with a proliferation of endoplasmic reticulum; cytosol and mitochondrial activity did not change. In contrast, in the presence of linoleic acid and PI total cellular activity was increased. In culture containing inositol, the intracellular phospholipid composition of strain INA-12 mycelium exhibited a two fold enrichment in PI at the expense of phosphatidylserine and its derives, phosphatidylethanolamine and phosphatidylcholine.Offprint requests to: M. Asther