本研究以轮枝镰孢菌JF-5-1(Fusarium verticillium)为指示菌,对实验室保存的132株乳酸菌进行抑菌筛查,并对该菌株产生的抑霉菌物质进行了初步探究。结果表明,17株乳酸菌展现了良好的抑制轮枝镰孢菌特性,对轮枝镰孢菌具有较强抑制作用的为91号菌株,经过16S rDNA鉴定其为鼠李糖乳杆菌(Lactobacillus rhamnosus)。菌株上清液对木瓜蛋白酶和胰蛋白酶不敏感,且热稳定性较好,热处理并未改变抑菌性。当pH=5时,抑菌率急速下降为25.0%,当pH大于等于5.5时,91号菌株抑菌活性全部丧失。故初步推测该抑菌物质可能为有机酸,其最小抑菌浓度为8.0 mg/mL。本研究筛选出来的乳酸菌应用在玉米等粮食防霉中,其可抑制轮枝镰孢菌对粮食的侵染且绿色安全,具有非常广阔的应用前景。
132 strains of Lactobacillus preserved in the laboratory were screened for inhibition by Fusarium verticillium JF-5-1. The results showed that 17 strains of lactic acid bacteria exhibited good characteristics of inhibiting Fusarium verticilliium. Strain 91 had a strong inhibitory effect on Fusarium verticillium,and was screened and identified as Lactobacillus rhamnosus by 16S rDNA. Furthermore,a preliminary investigation of the fungal inhibitory substance produced by this strain was conducted. The supernatant was insensitive to papain and trypsin,and had good thermal stability. Heat treatment did not change the bacteriostatic properties. When pH was 5,the bacteriostatic rate drops rapidly to 25.0%. When the pH was greater than or equal to 5.5,the antibacterial activity of strain 91 was completely lost. Therefore,it was preliminarily speculated that the bacteriostatic substance might be an organic acid,and the minimum bacteriostatic concentration was 8.0 mg/mL. The lactic acid bacteria selected in this study could be used in corn and other food mold prevention,which could inhibit the infection of Fusarium verticilliium on food with green and safe,and would have a very broad application prospect.