Bauchop T
Department of Biochemistry, Microbiology and Nutrition, University of New England, Armidale, N.S.W., Australia.
Biosystems. 1989;23(1):53-64. doi: 10.1016/0303-2647(89)90008-7.
The obligately anaerobic nature of the gut indigenous fungi distinguishes them from other fungi. They are distributed widely in large herbivores, both in the foregut of ruminant-like animals and in the hindgut of hindgut fermenters. Comparative studies indicate that a capacious organ of fermentative digestion is required for their development. These fungi have been assigned to the Neocallimasticaceae, within the chytridiomycete order Spizellomycetales. The anaerobic fungi of domestic ruminants have been studied most extensively. Plant material entering the rumen is rapidly colonized by zoospores that attach and develop into thalli. The anaerobic rumen fungi have been shown to produce active cellulases and xylanases and specifically colonise and grow on plant vascular tissues. Large populations of anaerobic fungi colonise plant fragment in the rumens of cattle and sheep on high-fibre diets. The fungi actively ferment cellulose which results in formation of a mixture of products including acetate, lactate, ethanol, formate, succinate, CO2 and H2. The properties of the anaerobic fungi together with the extent of their populations on plant fragments in animals on high-fibre diets indicates a significant role for the fungi in fibre digestion.
肠道内的原生真菌具有严格厌氧的特性，这使其有别于其他真菌。它们广泛分布于大型食草动物体内，在反刍类动物的前肠以及后肠发酵动物的后肠中均有发现。比较研究表明，它们的生长需要一个宽敞的发酵消化器官。这些真菌被归为壶菌纲裂殖壶菌目中的新美鞭菌科。对家养反刍动物的厌氧真菌研究最为广泛。进入瘤胃的植物材料会迅速被游动孢子定殖，游动孢子附着并发育成菌体。已证明厌氧瘤胃真菌能产生活性纤维素酶和木聚糖酶，并特异性地定殖于植物维管组织并在其上生长。在以高纤维日粮饲养的牛和羊的瘤胃中，大量厌氧真菌定殖于植物碎片上。这些真菌积极发酵纤维素，从而形成包括乙酸盐、乳酸盐、乙醇、甲酸盐、琥珀酸盐、二氧化碳和氢气在内的多种产物混合物。厌氧真菌的特性以及它们在以高纤维日粮饲养的动物的植物碎片上的种群数量表明，这些真菌在纤维消化中发挥着重要作用。
