利用纤维素原料生产柠檬酸菌株的筛选

从土壤中筛选分离到一株能利用纤维素原料产柠檬酸的黑曲霉菌株S。研究表明:预处理稻草为菌株适宜利用的纤维素原料;以3%预处理稻草为基质,菌株的发酵特性是发酵12h时CMCase活力达218.4U/mL,FPase活力达44.1U/mL,12h后酶活力下降;发酵60h产酸率达22%。通过对菌株的产酸驯化筛选和复筛,获得一株产柠檬酸性能稳定的菌株黑曲霉S6。黑曲霉S6可作为利用纤维素原料生产柠檬酸研究的出发菌株。 

Screen of a citric acid-producing strain with cellulose material

A strain of Asperillus niger which could produce citric acid with cellulose materials was isolated from the soil by screen. The results of study showed that the suitable cellulose material on the strain was pretreated rice straw. The characteristics indicated that it secreted cellucase were that the CMCase activity reached218.4U/mL, the FPase activity to 44.1U/mL, with 3% pretreated rice straw, at 12 h, and then decreased. The acid production rate reached 22% at 60 h. The strain Asperillus niger S6 which could produce citric acid stably was obtained by domesticated screening and rescreening. Asperillus niger S6 could be the strain of citric aicd-producing with cellulose materials.