Lactobacillus plantarum A491的筛选及其在苜蓿青贮中的应用研究

Study on screening of Lactobacillus plantarum A491 and its application in alfalfa silage

为筛选适合苜蓿青贮用乳酸菌,本研究对64株苜蓿附生乳酸菌进行多糖利用能力的考察,结果显示有5株乳酸菌能较好利用葡聚糖和木聚糖产酸,进一步的抑菌活性试验筛选出对李斯特氏菌、大肠杆菌和沙门氏菌都有较好抑菌活性的菌株A491。通过生理生化试验、16S r RNA基因序列分析及rec A基因扩增试验将筛选菌株A491鉴定为植物乳杆菌(Lactobacillus plantarum)。将菌株A491进行苜蓿青贮应用研究,青贮95 d后,与自然青贮和添加商业添加剂的处理组相比,添加菌株A491处理组的乳酸含量较高(P<0.05),而p H较低(4.62)(P<0.05),有害菌较少,发酵品质较好。表明菌株A491在苜蓿青贮中具有潜在的应用价值。

To screen the lactic acid bacteria for alfalfa silage,64 strains of lactic acid bacteria were isolated from al-falfa and their ability of polysaccharide utilization were measured.The results showed that 5 strains could use glucan and xylan to produce acid,and their antimicrobial activity were measured.A491 was selected by its excellent antimicrobial ac-tivity of Listeriosis,Escherichia coli and Salmonella enterica.The physiological and biochemical identification,sequence analysis of 16S rRNA and recA gene amplification experiments indicated that A491 was Lactobacillus plantarum.A491 and commercial inoculants were selected on alfalfa silage as additives.After 95 days ,the silages inoculated with strain A491 presented better fermentation quality,with higher contents of lactic acid (P < 0.05) and lower pH values (4.62) (P <0.05),less harmful bacteria,compared with the control and the silages inoculated with commercial inoculants.A491 showed the potential application value in alfalfa silage.