DEGRADATION OF LIGNIN-CARBOHYDRATE COMPLEX (LCC) BY WOOD-ROTTING FUNGI .3. STRUCTURAL-ANALYSIS OF WATER-SOLUBLE MATERIALS IN LIQUID CULTUREOF CORIOLUS-VERSICOLOR

When Coriolus versicolor (L.: Fr.) Quel. was incubated in a medium con taining a water-soluble lignin-carbohydrate complex (LCC-W) as a sole carbon source, the formation of materials precipitated by acidifying ( pH 2-3) the culture medium was found to start after 10 days of incubat ion. This precipitated fraction (P-A) was prepared with various incuba tion times up to 31 days, and its structural changes were investigated by chemical and spectroscopic analyses. Based on the time course of s tructural changes of the lignin portion of this fraction, the initial attack by C. versicolor was the formation of new phenolic hydroxyl gro ups, which probably was followed by an oxidation reaction to form new alpha-carbonyl and carboxyl groups. Although the latter reaction could be explained by the co-operative actions of laccase and other phenolo xidases, an uncharacterized lignin-degrading system was suggested to e xist to participate in the former reaction.