青藏高原耐低温乳酸菌在垂穗披碱草青贮中的应用

Application of lactic acid bacteria to Elymus nutans silage from the Tibetan Plateau

为探讨一株低温发酵戊糖片球菌Q6在不同温度条件下对垂穗披碱草(Elymus nutans)青贮饲料发酵品质的影响。本研究设置了对照组(清水,CK)、耐低温戊糖片球菌Q6及商品化的戊糖片球菌(APP)3个处理,分别在10、15、25℃温度下进行垂穗披碱草青贮,在青贮发酵30、60、90d后取样测定其发酵品质和化学成分。结果表明,添加耐低温戊糖片球菌Q6在15℃下青贮60d时,青贮饲料发酵品质明显优于CK组和APP处理组,有效降低了青贮料的pH,增加了乳酸含量,并保存更多的干物质。同时,添加菌株Q6不仅提高了青贮饲料中乳酸菌数量而且抑制了酵母和霉菌生长。因此,戊糖片球菌Q6是一株适宜于青藏高原牧草低温青贮的优良乳酸菌。

The study was conducted to investigate the effect of applying a low temperature fermentative strain of Pediococcus pentosaceus Q6 on the fermentation quality of Elymus nutans silage ensiled at different temperatures. Before ensiling of E. nutans, the grasses were treated without inoculation or with inoculation of either the strain of Pediococcus pentosaceus Q6 or a commercial strain P. pentosaceus （APP）. The treated grasses were then ensiled at 10, 15 and 25 ℃, respectively. The ensiled grasses were opened on 30, 60 and 90 d after fermentation for laboratory analysis. The results showed that after 60 days of fermentation at 15 ℃, the fermentation quality of the silage inoculated by P. pentosaceus Q6 was obviously better than the control silage or silage inoculated by APP. Inoculation of P. pentosaceus Q6 at ensiling had an effective reduction in silage pH, and also increased the concentration of lactic acid dry matter in ensiled grasses compared to the control silage or silage inoculated by APP. Meanwhile, application of P. pentosaceus Q6 not only increased the count of lactic acid bacteria, but also inhibited the growth of yeasts and molds in the grass silage. Therefore, P. pentosaceus Q6 is a candidate strain that can be used to making silage at low temperature in the Tibetan plateau.