1株嗜热性羽毛降解菌的分离鉴定及其酶学性质

发布时间：2018-03-20 21:00

  本文选题：嗜热性角蛋白降解菌　切入点：角蛋白酶　出处：《江苏农业科学》2017年10期 　论文类型：期刊论文

【摘要】：为从环境中得到1株嗜热高效角蛋白降解菌,用以羽毛粉为唯一碳源、氮源的培养基进行筛选。经筛选得到1株嗜热降解羽毛角蛋白的Y6菌株,通过对该菌株菌落、菌体形态特征、生理生化特性测定和16S rRNA分析,使用美国国立生物技术信息中心(NCBI)的BLAST进行16S rRNA的相似性比对。相似性比对结果显示,Y6菌株与地衣芽孢杆菌Xmb047(Bacillus licheniformis Xmb047)的同源性99%,初步认定该菌株为地衣芽孢杆菌(Bacillus licheniformis),命名为Y6(Gen Bank登陆号KY082766)。采用该菌降解完整羽毛,发酵72 h后,完整羽毛仅剩下羽轴,羽枝被完全降解,说明Y6菌株有着较强的羽毛降解能力;用不同浓度硫酸铵溶液盐析发酵产物上清液,筛选出硫酸铵浓度为70%时,分离的粗酶液总活性最高。酶活性试验表明,Y6所产蛋白酶最适反应温度为70℃,最适pH值为8.0,Fe~(3+)、Zn~(2+)对蛋白酶活性有较强的抑制作用,阴离子表面活性剂十二烷基硫酸钠(SDS)、金属蛋白酶抑制剂乙二胺四乙酸(EDTA)能较强地抑制蛋白酶活性,表明该蛋白酶属于金属蛋白酶。
[Abstract]:In order to obtain a thermophilic and high efficient keratin degrading strain from the environment, using feather powder as the sole carbon source and nitrogen source as the medium for screening, a thermophilic degradation of feather keratin strain Y6 was obtained. Cell morphology, physiological and biochemical characteristics and 16s rRNA analysis. The similarity comparison of 16s rRNA was carried out by using BLAST of the National Biotechnology Information Center. The similarity comparison results showed the homology of strain Y6 and Bacillus licheniformis Xmb047(Bacillus licheniformis Xmb047. The strain was preliminarily identified as Bacillus licheniformis. Licheniformis, named Y6GN Bank landing number KY082766, was used to degrade intact feathers, After 72 hours of fermentation, the whole feather was only left with the pinnacle, and the pinnacle was completely degraded, which indicated that the strain Y6 had strong feather degradation ability, and the supernatant of the fermentation product was salted out with different concentrations of ammonium sulfate solution, and the ammonium sulfate concentration was 70%. The enzyme activity test showed that the optimum reaction temperature and pH value were 70 鈩，

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