抑制黄曲霉菌的乳酸菌的分离及鉴定

Isolation and identification of Aspergillus flavus inhibiting lactic acid bacteria

【目的】从新疆传统发面面肥中分离筛选出能够抑制黄曲霉菌生长的乳酸菌,为改善和提高青贮饲料品质提供优良菌种。【方法】采用实验室纯培养方法对新疆传统发面面肥样品进行乳酸菌的分离,采用双层平板法筛选对发霉花生、玉米和变质青贮饲料中黄曲霉菌具有抑制作用的乳酸菌,并对其进行生理生化鉴定及同源性分析,构建系统发育树,明确各菌株的分类地位。【结果】从新疆传统发面面肥中分离出12株乳酸菌,通过抑菌试验筛选出F3、F11和F12 3株对黄曲霉菌具有抑制作用的菌株。生理生化试验发现,3株菌株均能在5,10,40和45℃温度条件下生长,在NaCl为3%和6.5%,pH 4~7条件下能良好生长,并且这3株菌均能利用多种碳源。经16SrDNA序列同源性分析,菌株F3与类芽孢杆菌(Paenibacillus sp.)MD9B2的同源性为100%,菌株F11与屎肠球菌(Enterococcus faecium)V9-156的同源性为100%,菌株F12与乳酸乳球菌(Lactococcus lactis)25F1的同源性为100%。【结论】从新疆传统发面面肥中筛选出能够抑制黄曲霉菌的3株乳酸菌,经鉴定分别为类芽孢杆菌(Paenibacillus sp.)、屎肠球菌(Enterococcus faecium)和乳酸乳球菌(Lactococcus lactis)。

【Objective】Lactic acid bacteria inhibiting Aspergillus flavus were isolated and screened from Xinjiang traditional sourdough samples to provide good strains for silage quality improvement.【Method】Lactic acid bacteria were isolated from traditional fermentation dough sample by traditional method,and the strains with antimicrobial activity against Aspergillus flavus were screened from the moldy peanuts,moldy maize and deteriorative silage by the double-layer plate method.Physiological and biochemical characteristics as well as homology of lactic acid bacteria were determined,phylogenetic trees was established,and taxonomic position of the strains was confirmed.【Result】A total of 12 lactic acid bacteria strains were isolated from the samples,and three of them could inhibit Aspergillus flavus.All the three strains could grow at the temperatures of 5,10,40 and 45℃,pH of 4-7,NaCl concentrations of 3%and 6.5%,and various carbon sources.Based on 16 SrDNA gene sequence and homology analysis,F3 and Paenibacillus sp.MD9 B2 had the similarity of 100%,F11 and Enterococcus faecium V9-156 had the homology of100%,and F12 and Lactococcus lactis 25 F1 had the similarity of 100%.【Conclusion】Three lactic acid bacteria with ability of inhibiting Aspergillus flavus were isolated and screened from Xinjiang traditional sourdough samples and they were identified as Paenibacillus sp.,Enterococcus faecium and Lactococcus lactis.