| 摘要 |
b -glucans is degraded with a fungus of the genus Oxyporus (Bourd & Galzin) Donk. The degradation may be achieved with a culture filtrate, a mycelium extract of the fungus or an enzyme obtained from the fungus. The preferred species is Oxyporus populinus (Schum. ex Fr.) Donk, otherwise known as Fomes connatus (Fr.) Gillet, Polyporus connatus (Fr.), Polystictus connatus (Fr.) Quel. The fungi may be grown under submerged culture in malt extract-peptone nutrient solutions, for example containing 2.0% malt extract and 0.02% peptone, at pH 5.8, 2% agaragar being added where solid nutrients are desired, or in specified solutions based on glucose, maltose, sucrose and cellulose powder or acid-swollen or alkali-swollen cellulose powders. Cellulose must be present in the nutrient medium for the synthesis of the cellulolytic system so that the nutrient solution for the main culture may comprise stated proportions of cellulose powder, casein hydrolysate, cornsteep powder and specified inorganic salts. Oxyporus populinus may typically be grown for about 8 days at 28 DEG C. The majority of the mycelium will then have formed lemon-like chlamydospores; the remaining spores are autolysed. Examples disclose the degradation with a culture filtrate obtained from Oxyporus populinus of cellulose powder, acid-swollen cellulose powder, filter paper, cotton thread and cotton pre-treated with aqueous caustic soda solution. Alkali-swollen celluloses, carboxymethylcellulose, lichenin and yeast cell walls consisting of 1, 3 - connected b -glucans may be degraded also. |
