Anaerobic fungi and their cellulolytic and xylanolytic enzymes

Anaerobic fungi are the inhabitants of the digestive tract of herbivorous mammals, ruminants as well as non-ruminants. One of the major characteristics of all anaerobic fungi examined thus far, is their production and secretion of a range of polysaccharide-degrading enzymes, including cellulases, xylanases and glucoside-hydrolases. The cellulolytic enzymes of the anaerobic fungusNeocallimastix frontalis have been shown to possess a high activity. Therefore anaerobic fungi and/or their enzymes could be interesting for many biotechnological applications including saccharafication of lignocellulosic residues, production of polysacchari-dehydrolysing enzymes. This review summarizes the present knowledge of anaerobic fungi with special emphasis on their cellulolytic and xylanolytic enzymes. Further, a comparison with aerobic fungi is made.Abbreviations G₂ cellobiose - G₃ cellotriose - G₄ cellotetraose - G₅ cellopentaose - HMM-complex high molecular mass complex - PNPF p-nitrophenyl--fucopyranoside - PNPG p-nitrophenyl--glucopyranoside