一株甲基营养型芽孢杆菌抑菌活性物质鉴定

Identification of Antibacterial Active Substances of a Strain of Bacillusmethylotrophicus

为研究一株甲基营养型芽孢杆菌拮抗特性及其抑菌活性物质,试验采用牛津杯法和平板对峙培养法,研究甲基营养型芽孢杆菌BFWR11对真菌的生物拮抗作用,分别采用酸沉淀、正丁醇萃取、硫酸铵沉淀从发酵上清液中提取脂肽、有机酸和粗蛋白,并基于代谢组学技术对其抑菌活性代谢产物进行了分析鉴定。甲基营养型芽孢杆菌BFWR11对赤霉菌、灰霉菌、黑曲霉菌均有明显的拮抗作用,发酵液及其不同提取物也表现出一定的抑制作用。正丁醇萃取物中分离鉴定到棕榈酸、阿扎胞苷、3-羟基苯甲酸、肉豆蔻酸、水杨酸等主要抑菌相关物质,粗蛋白提取物中分离鉴定出表面活性素合成酶亚基、聚酮合成酶、鞭毛相关蛋白等抑菌蛋白相关物质。甲基营养型芽孢杆菌BFWR11繁殖活力强,对真菌有显著的抑制作用。BFWR11菌株在LB肉汤中可产生多种抑菌活性物质进行协同抑菌,在食品加工及生物防治领域具有一定的应用价值。

To study the antagonistic properties and antibacterial active substances of Bacillus methylotrophicus,the experiment is carried out by using Oxford cup method and plate confrontation method to study biological antagonism of Bacillus methylotrophicus BFWR11 against fungi.Lipopeptide,organic acid and crude protein are extracted from the fermentation supernatant by acid precipitation,n-butanol extraction and ammonium sulfate precipitation respectively.The metabolites of antibacterial activity are analyzed and identified based on metabonomics.The Bacillus methylotrophicus BFWR11 has obvious antagonistic effects on Gibberella saubinetii,Botrytis cinerea and Aspergillus niger.The fermentation broth and different extracts show certain inhibitory effect on fungi.The main antibacterial substances such as palmitic acid,azacitidine,3-hydroxybenzoate,myristic acid and salicylic acid are isolated and identified from the n-butanol extracts.The bacteriostatic protein related substances such as surfactin synthase subunit,polyketide synthase and flagellar associated protein are isolated and identified from the crude protein extracts.Bacillus methylotrophicus BFWR11 has a fast reproduction rate and significant inhibitory effect on fungi.BFWR11 strain produces a variety of antibacterial substances in LB broth for synergistic inhibition,it has a certain application value in the field of food processing and biological control.