N^+注入选育益生菌及其产酶条件的研究

Breeding of Probiotic Bacterium by N^+ Implantationand Optimization of Fermentation Condition

出发菌株黑曲霉AN01,经离子束多次诱变得变异菌株AN02。结果表明,出发菌株AN01酸性蛋白酶、纤维素酶和果胶酶的酶活分别由原来的1 298U·mL-1、2 551U·mL-1和5 620U·mL-1相继提高到14 252U·mL-1、13 016U·mL-1和13 206U·mL-1。变异菌株AN02经传5代培养,产酶特性稳定。该菌株的最佳产酶条件为在培养基基础营养为麸皮、豆粕和玉米芯的条件下,最佳无机氮源为硫酸铵,最佳pH为5 0,最佳含水量为60%,最佳发酵温度为30℃,最佳发酵周期为96h。

A new strain Aspergillus niger AN02 was mutated from AN01 by N^+ implantation.The results showed that activities of acid-protease,cellulase and pectinase in Aspergillus niger were raised from 1 298 U·mL^(-1),2 551 U·mL^(-1) and 5 620 U·mL^(-1) to 14 252 U·mL^(-1),13 016 U·mL^(-1) and 13 206 U·mL^(-1) respectively.Characteristics of enzymes production in mutated strain Aspergillus niger AN02 kept stable by many times subculture.At the same time we study optimum conditions suitable for enzyme production in Aspergillus niger AN02,and the results demonstrated that enzymes activities in mutated strain Aspergillus niger were highest when the cultivate condition were as follows:fermentation temperature was 30℃,cultivate time was 96 hours,the water content in culture medium was 60 percent, pH was 5.0 and (NH_4)_2SO_4 was nitrogen source.