海洋细菌Bacillus coagulansspp.heishijiaosis发酵液抗真菌活性及其机制

Antifungal activity and mechanism of the bioactive substance derived from marine bacteria Bacillus coagulans spp.heishijiaosis fermentation broth

目的对凝结芽胞杆菌黑石礁新亚种LU-B02产生的抗白色念珠菌活性物质的作用靶位及抑菌谱进行了研究。方法采用山梨醇保护形态变异法结合扫描电镜超微结构观察研究了活性物质的作用靶位,最小抑菌浓度（MIC）法比较了该菌发酵液对不同真菌的抑菌活性。结果该活性物质抑制白色念珠菌细胞壁中的主要组分——葡聚糖的合成从而造成其细胞壁残缺。该活性物质具有抗真菌专一性,对革兰氏阳性代表菌金黄色葡萄球菌和革兰氏阴性代表菌大肠杆菌等细菌均无抑制效果,而对人体病原真菌抑菌效果较为明显,尤其是对白色念珠菌的抑制效果较好。MIC测定表明白色念珠菌对LU-B02活性物质高度敏感,相当于斯皮仁诺8～16μg,抑菌效价每毫升相当于3 500 U制霉菌素或洁尔阴活性的4倍。发酵液在酸性条件下加入0.2%冰片时,室温下存放6个月仍可保持良好的抗白色念珠菌活性。结论凝结芽孢杆菌黑石礁新亚种（Bacillus coagulans spp.heishijiaosis）产生的活性物质在控制以白色念珠菌为主的真菌感染方面具有良好应用前景。

Objective To study the antimicrobial targets and spectrum of the bioactive substance fromBacillus coagulans spp.heishijiaosis fermentation broth.Methods The antimicrobial targets and activity were determined by sorbitol protection morphological variation combined with scanning electron microscope and the minimum inhibitory concentration（MIC）,respectively.Results The bioactive substance exhibited strong antifungal activity,especially Canidia albicans,and the target maybe owing to the inhibition dextran synthesis resulting in incomplete cell wall.However,the bioactive substance had no effect on Gram-positive bacteria（Staphylococcus aureaus）and Gram-negative bacteria（Escherichia coli）.The MIC value was equivalent to 8-16μg Sporanox.The antifungal effect was 3500 Unystatin or 4times of Jieryin（an antifungal Chinese medicine）,respectively.The bioactive substance added 0.2 %borneol showed good activity against C.albicans after six month storage.Conclusion The bioactive substance fromB.coagulans fermentation broth showed good prospects in controlling C.albicans infections.