不同乳酸菌组合对苜蓿青贮细菌群落结构的影响

为探讨不同乳酸菌互作对苜蓿（Medicago sativa）青贮细菌群落结构的影响，以2种植物乳杆菌、乳酸片球菌、戊糖片球菌及凝结芽孢杆菌形成的6种乳酸菌组合按1.5 mL·kg^-1的添加量制作苜蓿青贮，以等量蒸馏水替代添加剂作为对照，45 d后运用高通量测序分析细菌群落结构。结果表明，各苜蓿青贮的优势乳酸菌群均为厚壁菌门（Firmicates）的乳杆菌属（Lactobacillus）和片球菌属（Pediococcus），二者相对丰度之和为65.4%~79.0%，其中含植物乳杆菌处理高于对照和含凝结芽孢杆菌处理；与对照相比，乳酸菌组合处理提高了菌群Chao1和ACE指数但降低了Simpson和Shannon指数；6个乳酸菌组合处理中，含凝结芽孢杆菌处理组与对照相似性较高，对苜蓿青贮细菌群落影响较小；相关分析表明，苜蓿青贮菌群结构和多样性可较好地解释其营养品质的变化。综上，乳酸菌组合在一定程度上改善了苜蓿青贮的细菌群落结构，其中含植物乳杆菌的组合效果较好。

Effects of Various Lactic Acid Bacteria Combinations on Bacterial Community Structure of Alfalfa Silage

To explore the interaction of various lactic acid bacteria on the bacterial community structure of alfalfa silage,the experiment was conducted with six lactic acid bacteria combinations of Lactobacillus plantarum (No. ACCC11016,No. CICC20765),Pediococcus acidilactici (No. CGMCC 1.4),Pediococcus pentosaceus (CICC 22737),and Bacillus coagulans (No. ACCC10229). The lactic acid bacteria combination was used to make alfalfa silage at the dosage of 1.5 mL·kg^-1,the treatment with equivalent distilled water replacing additive was as the control,and the bacterial community was analyzed after 45 d through high throughput sequencing methods. The results showed that the dominant lactic acid bacteria community were Lactobacillus and Pediococcus belonging to Firmicates, and the relative abundance was 65.4%~79.0%,in which the relative abundance of the treatment containing L. plantarum was higher than that of the control and the treatment containing B. coagulans. Compared with the control,the indices of bacteria community richness (Chao1 and ACE index) increased while the community diversity indices (Simpson and Shannon) decreased. Among the six lactic acid bacteria combinations,the treatments containing B. Coagulans had higher similarity with the control,indicating that it had few effects on bacterial community of alfalfa silage. The correlation analysis showed that the bacteria structure and diversity of alfalfa silage could well explain the change of nutrient quality. In conclusion,the lactic acid bacteria combinations could improve the bacteria community structure of alfalfa silage,in which the combination containing L. plantarum was superior to the combinations containing B. coagulans.