一株抗菌蛋白产生菌的筛选鉴定及其纯化

Screening and Identification of Antimicrobial Protein-producing Strain

从土壤中筛选到1株产生广谱抑菌活的抗菌蛋白菌株ZHL24。该抗菌蛋白对大肠杆菌(Escherichia coli)、藤黄微球菌(Mirococcus luteus)、铜绿假单胞菌(Pseudomonas aeruginosa)、蜡样芽孢杆菌(Bacillus cereus)、白色念珠菌(Candida albicans)、匍枝根霉(Rhizopus stolonifer)等多种病原细菌和真菌有强烈的抑制活性。通过形态特征、生理生化特征以及16S rDNA序列比对和系统发育分析,鉴定其为枯草芽孢杆菌(Bacillus subtilis)。采用硫酸铵分级盐析、离子交换层析(DEAE-Sepharose FF)、分子筛凝胶过滤层析(Sephadex G-15)等方法从菌株ZHL24发酵液中分离纯化到电泳纯的抗菌蛋白。经SDS-PAGE检测显示为单一条带,其分子质量约为26.2kD。氨基酸组成成分检测抗菌蛋白含有14种氨基酸。

A new strain,ZHL24,capable of producing broad-spectrum antimicrobial protein was isolated from soil.The antibacterial protein produced by the strain showed a high inhibitory activity towards many pathogenic bacteria and fungi such as Escherichia coli,Mirococcus luteus,Pseudomonas aeruginosa,Bacillus cereus,Candida albicans and Rhizopus stolonifer.This new strain was identified as Bacillus subtilis based on physiological characteristics,biochemical characteristics and 16S rDNA sequence.The antimicrobial protein was purified to homogeneity through ammonium sulfate precipitation,ion exchange chromatography（DEAE-Sepharose FF） and gel filtration（Sephadex G-15）.SDS-PAGE revealed a single band at the molecular mass of 26.2 kD.Amino acid composition analysis showed that the antibacterial protein contained 14 kinds of amino acids.