摘要
从原筛选的产酶菌株CW2出发,经多次紫外诱变、初筛和复筛后,获得了变异菌株CW2M3,其产酶水平为原菌株的332.7%,且具有良好的遗传稳定性.薄层层析证明,CW2M3分泌的新型淀粉酶能有效地催化淀粉降解产生异麦芽低聚糖,产物主要包括异麦芽糖、潘糖、异麦芽三糖等.用正交法结合薄层层析法确定了各因素对CW2M3产酶水平的影响,结果表明,培养温度是显著因素,CW2M3的最适产酶条件为:用牛肉膏培养基(牛肉膏0.7%、蛋白胨0.7%、NaC l 0.5%、pH 7.0)培养,温度40℃,时间12 h.用该酶催化淀粉转化为异麦芽低聚糖时,酶促反应时间和温度均是显著影响因素,酶催化淀粉降解的最适条件为:温度65℃,酶促反应1.0 h,体系pH为7.0.
Strain CW2M3 was mutagenised from strain bacillus thermolicheniformis CW2 by ultraviolet ray, and the activity of secreted neoamylase by CW2M3 is increased by 232.7% compared with that of CW2 under the identical conditions. Moreover, strain CW2M3 is genetically stabile. The results of thin layer chromatography of the products from starch catalyzed by the neoamylase demonstrate that the neoamylase can be used to catalyze starch to produce isomahooligosaccharide, including isomaltose, panose, isomaltotriose, from starch. The optimum conditions under which the neoamylase was secreted by CW2M3 were confirmed by orthogonal tests. The results show that the most important parameter to secrete the neoamylase is temperature for culturing CW2M3 and the optimum conditions to secrete the neoamylase are as follows. The strain CW2M3 should be cultured in the medium of 0.7% brewis, 0.7% peptone, 0.5% NaC1, pH 7.0 at 40℃ for 12 h, whereas the most important parameter to utilize the neoamylase is catalytic duration and the optimum conditions to utilize the neoamylase are in pH 7.0 starch system, at 65℃ for 1.0 h.
出处
《吉林大学学报（理学版）》
CAS
CSCD
北大核心
2006年第5期834-838,共5页
Journal of Jilin University:Science Edition
基金
吉林大学研究生创新基金(批准号:理学304028)
