枯草芽孢杆菌固态发酵产脂肽培养基优化及脂肽的初步鉴定

李萌; 李丽; 张坦; 牟海津

doi:10.13386/j.issn1002-0306.2019.06.033

枯草芽孢杆菌固态发酵产脂肽培养基优化及脂肽的初步鉴定

Optimization of Lipopeptide Production Medium by Solid-State Fermentation of Bacillus subtilis and Preliminary Identification of Lipopeptide

摘要

摘要: 利用枯草芽孢杆菌N-2,以豆粕为主要基质,优化固态发酵产抗菌脂肽以提高脂肽产量。利用高效液相色谱法对发酵产生的抗菌物质进行初步鉴定;随后通过Plackett-Burman设计法和响应面优化,对枯草芽孢杆菌产脂肽的关键因子进行筛选并优化最佳培养基条件组合。结果表明,初步分析该抗菌物质主要成分为脂肽,其组分包括伊枯草菌素(m/z 1043.6、1057.5、1070.2、1084.0),丰原素(m/z 717.4、734.7);筛选确定MgSO₄、K₂HPO₄、FeSO₄添加量为3个影响发酵的显著性(p<0.05)因素,确定发酵培养基成分的最优组合为MgSO₄ 0.39%、K₂HPO₄ 1.70%、FeSO₄ 0.13%,在其条件下脂肽的抑菌率达到75.62%±0.36%,该结果为脂肽的工业化生产奠定基础。

Abstract: In order to improve the yield of antimicrobial lipopeptides, soybean meal was used as the major substrate for solid-state fermentation to produce antimicrobial lipopeptide in this study. The antimicrobial substances were preliminarily identified by a high performance liquid chromatography. Subsequently, the optimization was performed by Plackett-Burman design and response surface methodology. Results showed that:The main antimicrobial lipopeptides produced were iturin (m/z 1043.6, 1057.5, 1070.2, 1084.0), fengcin (m/z 717.4, 734.7).Plackett-Burman design method was further adopted to screen the significant factors affecting fermentation. And the addition amount of MgSO₄, K₂HPO₄, and FeSO₄ were identified as the three significant factors (p<0.05) affecting the fermentation. Under the optimized conditions of MgSO₄ 0.39%, K₂HPO₄ 1.7% and FeSO₄ 0.13%, the inhibitory rate of antimicrobial lipopeptide reached 75.62%±0.36%, which laid the foundation for the industrial production of antimicrobial lipopeptide.