一株高效降解蚕蛹蛋白的菌株筛选与初步鉴定

Screening and Primary Identification of a Microbial Strain that Degrades Silkworm Pupa Protein with High Efficiency

筛选、鉴定能高效降解缫丝蚕蛹蛋白的菌株,用于提高缫丝蚕蛹生产食品和动物饲料的营养价值。从蚕蛹储藏车间及周围的土壤中收集细菌,经富集培养、干酪素平板初筛和发酵蚕蛹蛋白复筛,获得一株产蛋白酶活性较高的菌株,命名为CY21。该菌株在32℃、pH 7.0条件下培养60 h后所产蛋白酶的比活力可达到272.7 U/mg。通过形态学观察、经典生理生化试验以及16S rDNA序列系统发育分析,初步确定该菌株为芽孢杆菌属(Bacillus)与解淀粉芽孢杆菌(Bacillus amyloliquefaciens)亲缘关系很近的一个菌株。

In present study, microbial strains which have high efficiency in degrading silkworm pupa protein from reeled cocoons were screened and identified to improve nutritional value of food and animal forage prepared from silkworm pupa of reeled cocoons. Through enrichment culture, primary screen with casein plate, and secondary screen with fermented silkworm pupa protein, a microbial strain named CY21 producing high activity protease was obtained from the silkworm pupa storage house and its surrounding soil. After being cultured under 32 ℃ and pH 7.0 for 60 h, specific activity of protease produced by this strain could reach 272.7 U/mg. Based on morphological observation, typical physio-biochemical tests and 16S rDNA phylogenetic analysis, this strain was preliminarily identified as a species belonging to the genus Bacillus and had the closest genetic relationship with Bacillus amylofiquefaciens.