Biology, fiber-degradation, and enzymology of anaerobic zoosporic fungi

AbstractAnaerobic zoospore-producing fungi that inhabit the gastrointestinal tract of herbivores, especially ruminants, have recently been discovered. These fungi have been isolated from the rumen, hind gut, and the feces of ruminants. Thirteen species, belonging to five genera, of these fungi have been assigned to the class Chytridiomycetes. These species arc classified according to the number of flagella on the zoospores and the types of thalli that develop from the zoospores. Their life cycle consists of a zoospore that encysts and develops into a vegetative thallus with zoosporangia, which at times become resting sporangia. These fungi produce a wide range of active hydrolytic enzymes, notably cellulases and xylanases, that provide them with the potential to degrade the major structural polysaccharides in plant cell walls. Their cellulases are among the most active reported to date and solubilize both amorphous and highly ordered cellulose. Their esterases are active against both feruloyl and p-coumar...