| 摘要 |
Cellulose and hemicellulose-splitting enzymes are obtained by cultivating a mould or fungus on a nutrient medium rich in cellulose until spores are plentifully developed and extracting the enzymes. Suitable media are bran and sawdust impregnated with nutrient solutions; materials such as grain and malt are not regarded as "rich in cellulose." Suitable moulds are of the genera aspergillus, penicillium, rhizopus, botrytis, fusarium, and oidium. The enzymes are extracted with water and may be purified by adsorption by metal oxides and hydroxides, kaolin, silica and the like in an acid medium and elution in an alkaline medium; the solution may be first dialyzed. The cellulase may be freed from xylanase by adsorption with animal charcoal in an acid medium and elution in an alkaline medium. The removal of cellobiase may be effected by adsorption with natural aluminous materials such as bauxite and diaspore which do not adsorb cellulase. Inulin-and mannane-splitting ferments and inert substances may be removed by dialysis against flowing water. The enzymes may be isolated by precipitation with alcohol, and the precipitate may be washed with dilute alcohol to remove unpleasant taste. In an example, bran is stirred with water, which may contain nutrient salts, sterilized at 100--120 DEG C., cooled to 30 DEG C., inoculated with aspergillus orycae and left for 6 days at 30 DEG C.; at 40 DEG C. 3 to 4 days would be required, but at 25 DEG C. a much longer time. The mass is extracted with water, concentrated and dried. The Specification as open to inspection under Sect. 91 states that the individual enzymes in the extract may be separated, and mentions grain seeds and malt as suitable initial materials. This subject-matter does not appear in the Specification as accepted.
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