冠突散囊菌抑菌产物培养基优化及分离鉴定

Fermentation Optimization of Culture Medium and Isolation and Identification of Antimicrobial Active Substances from Eurotiumcristatum

采用响应面法优化冠突散囊菌FS-10产抑菌活性物质的发酵培养基配方,采用高效液相色谱、基质辅助激光解吸电离飞行时间质谱和傅里叶红外光谱对其抑菌活性产物进行分离纯化及结构鉴定。结果表明,冠突散囊菌FS-10产抑菌物质最佳培养基的配方为:碳源(无水葡萄糖)7.5%、氮源(硝酸钠)0.65%、氯化钾4.5%,优化后发酵液对浓度为1×10^(5) CFU/mL嗜冷菌菌悬液的抑菌率为54.4%。经分离纯化获得两个抑菌活性组分FS-Ⅳ、FS-Ⅵ,分子质量分别为1630.8 u和840.5 u,推测其结构分别为杂多糖的衍生化合物和酰胺类衍生化合物。这两个组分对食源性腐败菌,包括假单胞菌、希瓦氏菌和嗜冷菌有显著的抑制作用,并有良好的热稳定性和酸碱稳定性。

In this work,response surface methodology was used to optimize the fermentation medium components of E.cristatum FS-10 producing antibacterial active substances.Meanwhile,the antibacterial activity products were isolated and preliminary identification through highperformance liquid chromatography(HPLC),matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF-MS)and Fourier transform infrared(FT-IR)spectrometry.The results showed that the optimal medium components were determined as follows:anhydrous glucose(carbon source)7.5%,sodium nitrate(nitrogen source)0.65%,and potassium chloride 4.5%.Under the optimized fermentation conditions,the bacteriostasis rate reached 54.4%against the suspension of Psychrophile bacteria(1×10^(5) CFU/mL).Two antibacterial active components(FS-Ⅳ and FS-Ⅵ)were isolated and identified.The molecular mass of component FS-Ⅳ and FS-Ⅵ were 1630.8 u and 840.5 u,respectively,which might imply the existence of heteropolysaccharide derivative compounds and amide derivative compounds.Antibacterial compounds could inhibit the growth of some foodborne bacteria,including Pseudomonas,Shewanella and Psychrophile.They were stable to heat and acid-base conditions.