培养基组成对贝莱斯芽孢杆菌产抑真菌成分的影响

Effect of medium compositions on the production of antifungalcomponents by Bacillus velezensis

贝莱斯芽孢杆菌能够同时产生蛋白类和脂肽类等多种抑真菌的脂肽类物质,产物中各组分的具体组成和含量与培养基组成紧密相关。为获得最有利于主要抑菌成分产生的最佳条件,以炭黑曲霉为指示菌,考察了不同培养基组成和培养时间对贝莱斯芽孢杆菌发酵液抑菌活性和主要抑菌成分的影响。结果表明,培养基组成对抑菌成分的总产量及组分构成有显著影响:Landy培养基更利于菌体生长,但营养肉汤培养基(NB)则更有利于抑菌成分的合成;牛肉膏有利于抑菌成分的产生与积累,而蛋白胨则相反。同时,菌体在Landy培养基中所产抑菌物质主要是蛋白类,而在NB培养基中主要为脂肽类。经过优化组合,确定出最有利于总体抑菌物质合成的培养基组成为:葡萄糖20 g/L,NaCl 5 g/L,牛肉膏15 g/L,谷氨酸钠5 g/L,KH2PO420 g/L,MgSO4·7H2O 10 g/L,KCl 10 g/L,FeSO43 mg/L,MnSO4100 mg/L,CuSO 43.2 mg/L。此条件下的菌体生长量比Landy培养基提高了75.9%,发酵液的抑菌活性比用NB培养基提高了21.9%,而且脂肽类抑菌成分比例较高。

Bacillus velezensis can produce different kinds of antifungal proteins and lipopeptides at the same time.The specific composition and the content of each component in the culture of B.velezensis were greatly influenced by the composition of the medium.In order to obtain the optimal conditions for the production of antifungal components,the effects of different medium compositions and cultivation times on the antifungal activity and components of B.velezensis fermentation broth were investigated,using Aspergillus niger as a pathogenic fungus indicator.As results,the composition of the medium had a significant effect on the total yield and composition of the antifungal components.Landy medium was found to be more beneficial to cell growth,while NB medium was more beneficial to the production of antifungal compounds.The beef extract benefited the production of antifungal compounds,while peptone did not.The produced antifungal compounds were mainly proteins in Landy medium,while those were mainly lipopeptides in NB medium.The optimal medium composition for the accumulation of overall antifungal components were 20 g/L glucose,5 g/L sodium chloride,15 g/L beef extract,5 g/L sodium glutamate,20 g/L KH2PO4,10 g/L MgSO 4·7H2O,10 g/L KCl,3 mg/L FeSO4,100 mg/L MnSO4,and 3.2 mg/L CuSO4.This condition improved the cell growth by 75.9%compared with that of the Landy medium and increased the overall antifungal activity by 21.9%than that of the NB medium,and the proportion of lipopeptide was higher.