一株产淀粉酶芽胞杆菌SY200的鉴定及其对动物病原菌的生物拮抗试验

目的对一株产淀粉酶芽胞杆菌SY200进行鉴定及其对动物病原菌的生物拮抗试验。方法提取芽胞杆菌SY200基因组DNA,采用细菌16S rRNA通用引物进行PCR扩增及对扩增到的目标片段的测序,将测序结果与NCBI上已知菌种的16S rRNA序列进行BLAST对比,并构建系统进化树进行分析。采用滤纸片法和牛津杯法分别研究该芽胞杆菌的全菌液及培养物上清液对3株病原菌的生物拮抗。结果结合细菌形态观察及生理生化特性鉴定,最终确定菌株SY200为甲基营养型芽胞杆菌(Bacillus methylotrophicus);芽胞杆菌SY200全菌培养液和培养上清液对产肠毒素大肠埃希菌、鸡白痢沙门菌、金黄色葡萄球菌均有较强的生物拮抗作用,抑菌物质主要为细菌的代谢产物。结论芽胞杆菌SY200被鉴定为甲基营养型芽胞杆菌,该菌株对3株动物性病原菌具有较强的生物拮抗作用。

Identification of a strain of amylase-producing Bacillus sp. SY200 and its biological antagonism against animal pathogenic bacteria

Abstract: Objective To identify an amylase-producing strain of Bacillus sp. SY200 and analyze its biological antagonism against animal pathogenic bacteria. Methods The genomic DNA was extracted from Bacillus sp. SY200, then the target 16S rRNA fragments were amplified with the universal primers by PCR. The sequence and alignment analysis were performed using the NCBI with BLAST data base. The system of evolutionary tree was built and analyzed subsequently. Biological antagonism of the basic culture liquid and culture supernatant of the bacteria SY200 against three stains of animal pathogenic bacteria were measured by using filter-paper method and Oxford cup method respectively. Results In combination with the morphological and physiochemical characteristics, the strain SY200 was identified as Bacillus methylotrophicus. The basic culture liquid and culture supernatant of SY200 showed strong biological antagonistic effect against enterotoxigenic Escherichia coli, Salmonella pullorum and Staphylococcus aureus; the antibacterial substances mainly existed in bacterial metabolites. Conclusion Bacillus sp. SY200 is identified as Bacillus methylotrophicus with strong biological antagonism against three strains of animal pathogenic bacteria.