饲用复合酶优良菌株选育及其发酵工艺研究

从实验室保藏的菌株中,通过诱变选育出一株酸性蛋白酶高产菌株黑曲霉(Aspergillus niger)UV11,对菌株发酵产酶的培养基组成及培养条件等工艺参数进行了优化研究.结果表明,菌株UV11在m(麸皮)∶m(花生壳粉)=6∶4,豆粕质量分数10%,(NH4)2SO42%,MgSO4.7H2O 0.05%,K2HPO40.1%的培养基质上,控制m(料)∶m(水)=1∶1.1,接种量105～106个/g,28～30℃下培养24～30 h时,菌株UV11的产酶量:酸性蛋白酶1190 U/g,纤维素酶8024 U/g,木聚糖酶5192 U/g,糖化酶1080 U/g.对菌株中试生产时的产酶规律和酶的热稳定性进行了研究,发现菌株UV11所产的复合酶具有良好的热稳定性,可用于饲料工业中颗粒料的加工生产.

The Strain Breeding of Aspergillus niger for Feed-complex Enzymes and Its Fermentation Factors Optimalization

Through the mutagenesis of Aspergillus niger conidia and its protoplasts with the ultraviolet,we obtained an excellent strain A.niger UV11 capable of producing high-yield acid proteases,xylases and cellulases etc.After several significant factors and media optimalizating studies,we concluded that：the media of wheatbran/shell powder of peanut 6∶4,soybean-meal 10%（,NH4）2SO4 2%,MgSO4.7H2O 0.05%,K2HPO4 0.1%,the ratio of materials and water 1∶1.1 were suited for UV11strain to producing complex enzymes.And with a conditions of inoculum 105～106/g,culture temperature of 28 ～30 ℃ for 24 ～30 h,the complex enzymes productions are as fouows：acid proteases 1190 U/g,xylases 5192 U/g,cellulases 8024 U/g and the glucoamylase 1080 U/g.Furthermore,the complex heatstationary property were tested and the result showed that after 85 ℃,60 min treatment,the survival enzyme activity of the complex were more than 90%.