一株拮抗菌产生的抗菌物质的分离纯化与初步鉴定

Isolation,Purification,and Preliminary Identification of an Antibacterial Substance Produced by an Antagonistic Strain

试验旨在分离纯化XDH菌株产生的抗菌物质,并初步鉴定有效抗菌物质的结构。从泰山林地土壤中分离获得一株对大肠杆菌及鸡白痢沙门氏菌等多种动物致病菌具有较强拮抗作用的短短芽孢杆菌XDH,通过硫酸铵盐析和层析技术对该菌株产生的抗菌物质进行了分离纯化,对纯化后的抗菌物质进行了性质研究,并对抗菌物质B组分进行了结构鉴定。结果为:经过CM Sepharose FF离子交换层析、Sephadex G25凝胶层析对抗菌物质进行分离纯化,纯化后的抗菌物质对大肠杆菌的最小抑菌浓度(MIC)、最小杀菌浓度(MBC)分别为2.34μg/mL和4.69μg/mL,对鸡白痢沙门氏菌的MIC、MBC分别为0.63μg/mL和1.25μg/mL。采用AKTA Explore10层析系统对抗菌物质进一步分离纯化,获得A、B、C三个活性组分,其中,活性组分B的质谱解析结果显示,其分子量为1570.9 Da,推断为一新的多肽类抗菌物质。

The purpose of the experiment is to isolate and purify the antibacterial substances produced by XDH strain,and preliminarily identify the structure of effective antibacterial substances.A strain of Bacillus brevis XDH,which has strong antagonistic effect against many animal pathogenic bacteria such as Escherichia coli and Salmonella pullorum,was isolated from the soil of Mount Taishan forest land.The antibacterial substances produced by this strain were separated and purified by ammonium sulfate salting out and chromatography technology,The properties of the purified antibacterial substance were studied,and the structure of component B of the antibacterial substance was identified.The results were as follows:after separation and purification of antibacterial substances by CM Sepharose FF ion exchange chromatography,Sephadex G25 gel chromatography and AKTA Explore10 chromatography system,the MIC and MBC of the purified antibacterial substances against Escherichia coli were 2.34μg/mL and 4.69μg/mL,respectively,and against Salmonella pullorum were 0.63μg/mL and 1.25μg/mL,respectively.The mass spectrometry analysis results of active substance component B show that its molecular weight is 1570.9 Da,which is inferred as a new peptide antibacterial substance.