摘要
为获得枯草芽孢杆菌产β-甘露聚糖酶的最佳发酵条件,分别对碳源、氮源、碳氮质量比、发酵时间和培养温度进行了单因素实验,在此基础上对发酵温度、接种量、培养基初始pH值和发酵时间四因素进行了L9(34)正交优化试验.结果表明枯草芽孢杆菌分泌β-甘露聚糖酶的最佳碳源为40 g/L魔芋精粉,最佳氮源为5 g/L酵母抽提物,两者最佳质量比为5∶1,最佳发酵条件为30℃的条件下摇瓶培养28 h;最佳发酵参数组合为发酵温度30℃、接种量5%、培养基初始pH6.5、发酵时间28 h;各因素对枯草芽孢杆菌产β-甘露聚糖酶的影响程度大小依次为发酵时间>发酵温度>接种量>培养基初始pH,其中发酵时间对产酶的影响最为显著.
Mono-factor and orthogonal analysis were applicd to obtain the optimal fermentation conditions for β- mannase from Bacillus subtilis. The five factors： carbon, nitrogen, ratio of carbon and nitrogen, incubating temperature and incubation time were tested respectively. The four factors,including incubating temperature, inoculum size, original pH value and incubation time were designed in L9（3^4 ） for orthogonal analysis on the basis of mono-factor analysis. The result showed the optimal carbon, nitrogen, their optimal mass concentrations and their mass ratio are kanjac powder, yeast extract, 40 g/L, 5 g/L and 5 ： 1 respectively. The optimal incubation temperature is 30 ℃, by 28 h. The optimal parameter group was incubating temperature 30 ℃, inoculum size 5 %, original pH 6.5 and incubation time 28 h. Effect on β-mannase activity drops according to the order of incubation time, incubating temperature, inoculum size and pH. Incubation time has a remarkable effect on production of β-mannasc.
基金
a grant from Anhui academy youth sponsored project(2005jql071)
Anhui academy sponsored project in natural science(kj2007b114)
