贝莱斯芽孢杆菌生物学特性及体外降解霉菌毒素研究

Biological Characteristics and In Vitro Mycotoxin Degradation of Bacillus velezensis

为了筛选一株抗逆性强、抑制致病菌、产酶及维生素等益生物质且可降解霉菌毒素的益生菌,对自主筛选得到的贝莱斯芽孢杆菌(BLS-1)进行最适温度、pH、生长曲线及产酶、抑菌能力、抗逆性研究,并通过发酵罐发酵,对发酵液中多种酶及维生素含量进行了考察;通过体外降解的方式考察BLS-1对多种霉菌毒素的降解能力。结果表明:自主筛选的贝莱斯芽孢杆菌BLS-1在pH 2.5~3.5、胆盐浓度0.1%~0.5%及胃液肠液环境中具备良好的耐酸、耐胆盐、耐胃肠液能力;最适温度37℃、最适pH为6、培养时间24~30 h时芽孢形成率最高,生长进入稳定期并于28 h达到芽孢量顶峰;菌株发酵液代谢产物及菌体对大肠杆菌具有中敏的抑制作用;发酵液中含有多种酶、维生素等益生物质,且对玉米赤霉烯酮(ZEN)、呕吐毒素(DON)、黄曲霉毒素(AFB1)、伏马毒素(FB)、赭曲霉毒素(OT)有降解作用。贝莱斯芽孢杆菌BLS-1生物学特性良好,抗逆性强,可抑制大肠杆菌,同时对玉米赤霉烯酮、呕吐毒素、黄曲霉毒素、伏马毒素具有降解作用。

In order to screen a probiotic strain that has strong stress resistance,inhibits pathogenic bacte⁃ria,produces enzymes and vitamins,and can degrade fungal toxins,a series of studies were conducted on the independently screened Bacillus velezensis(BLS-1)such as optimal temperature,pH,growth curve,enzyme production ability,antibacterial ability and stress resistance,the contents of various enzymes and vitamins in the fermentation broth obtained through fermentation in a fermentation tank were measured,the degradation ability of Bacillus subtilis to various fungal toxins was investigated through in vitro degra⁃dation.The results showed that the independently screened Bacillus velezensis(BLS-1)had good acid re⁃sistance,bile salt resistance,and gastric and intestinal fluid resistance when tested in pH 2.5-3.5,bile salt concentration 0.1%-0.5%,and gastric and intestinal fluid environments;the strain had the highest spore formation rate under the optimal temperature of 37℃,optimal pH of 6,and cultivation time of 24-30 hours,and entered a stable stage of growth and reached its peak in spore count after 28 hours of cultivation;the metabolites and bacteria of the fer⁃mentation broth of the strain had moderately sensi⁃tive inhibition effect on Escherichia coli;the fer⁃mentation broth contained a variety of enzymes,vi⁃tamins and other beneficial substances,and had degradation effects on zearalenone(ZEN),deoxynivalenol(DON),aflatoxin B1(AFB1),fumonisin(FB),and ochratoxi(OT).The Bacillus velezensis(BLS-1)had good biological characteristics and strong stress resistance and could inhibit Escherichia coli,and it had degradation effects on zearalenone,deoxynivalenol,aflatoxin,and fumatoxin at the same time.