摘要
从多年被畜禽血液污染的土样中分离筛选出一株降解Hb能力强的自然菌株,并对其进行连续5代定向诱变。利用PCR扩增法和Neighbor-joining方法测定和分析了诱变菌种16S rD-NA序列,对筛选出的自然菌株及诱变菌株进行了鉴定,为短小芽孢杆菌(B.pumilus);二阶导数红外光谱法探测到其分子结构具有短小芽孢杆菌(B.pumilus)典型分子结构特征;SDS-PAGE凝胶电泳中发现短小芽孢杆菌(B.pumilus)产蛋白酶对Hb降解的断裂位点发生了变化。对Hb降解产物及产蛋白酶活力的测定结果表明:经连续5代诱变的短小芽孢杆菌(B.pumilus)对Hb降解能力比筛选出的自然菌株强,其蛋白酶活力比自然菌株提高了近3倍,Hb降解产物中的可溶性蛋白质质量分数、游离氨基酸质量浓度分别从3.69%、14.4 mg/dL提高到4.12%、24.6 mg/dL。
In this manuscript, a kind of natural strain, which had more degraded ability of Hb, was isolated from poultry blood polluted soil. The original strain was continuous mutated for five generation. The strain was determined to be Bacillus pumilus by 16SrRNA sequencing and Neighbor-joining methods. The second derivative infrared spectrum result showed that the strain had a typical molecular structure characteristic of B. purnilus. SDS-PAGE result illustrated that the protease degradation location on Hb was changed. The final B. purnilus strain had a stronger ability in degradation of Hb than its parent strain. The protease activity was improved about three times than that of the parent strain. The content of soluble protein, free amino acids was improved from 3.69% and 14.4 mg/dL to 4.12% and 24.6 mg/dL, respectively.
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2008年第3期68-72,共5页
Journal of Food Science and Biotechnology
基金
国家自然科学基金项目(30270976)
国家“十一五”重大科技项目
