Abstract
SUMMARY The metabolism of various lignin-related aromatic compounds by several soil Hyphomycetes and yeast-like fungi was investigated. Adaptation studies with whole organisms and cell-free extracts confirmed previously proposed metabolic pathways (Henderson & Farmer, 1955; Henderson, 1960). It was shown that protocatechuic acid is an intermediate in the metabolism of vanillin and ferulic acid. Protocatechuic acid oxidase activity of cell-free extracts of Pullularia pullulans was found to be stimulated by ferrous ions and to depend on -SH groups.