THE EFFECT OF RUMEN CHITINOLYTIC BACTERIA ON CELLULOLYTIC ANAEROBIC FUNGI

The polycentric anaerobic fungus Orpinomyces joyonii A4 was cultivated on microcrystalline cellulose alone and in association with the rumen chitinolytic bacterium Clostridium sp, strain GhK5, which shows stron g phenotypic similarity to Clostridium tertium. The presence of strain ChK5 significantly depressed the solubilization of microcrystalline c ellulose, the production of short-chain fatty acids (SCFA) and the rel ease of endoglucanase by the fungus, Go-culture of the monocentric ana erobic fungus Neocallimastix frontalis strain REI, Neocallimastix sp, strain G-1 and Caecomyces sp, strain SC2 with strain ChK5 also resulte d in depressed fungal cellulolysis, Cell-free supernatant fluids from strain ChK5 inhibited the release of reducing sugars from carboxymethy lcellulose by cell-free supernatant fluids from O. joyonii strain A4, Strain 007 of the cellulolytic anaerobe Ruminococcus flavefaciens was also shown to produce small amounts of soluble products upon incubatio n with colloidal chitin. Mixtures of culture supernates from this bact erium and from O. joyonii strain A4 showed cellulase activity that was less than that of the component cultures, It is suggested that the ab ility of some rumen bacteria to hydrolyse or transform chitin may be a n important factor in the interactions between bacteria and fungi in t he rumen.