苜蓿青贮饲料中优良乳酸菌菌株的筛选

本研究从苜蓿（Medicago sativa L.）青贮饲料中分离得到若干株乳酸菌，对所有菌株进行生长曲线和产酸速率测定，发现其中8个菌株产酸速率较快，能于24h内将培养基pH值降至4.0以下。根据形态、生化鉴定及16S rDNA同源性序列分析，鉴定4株为植物乳杆菌（Lactobacillus plantarum），2株为戊糖片球菌（Pediococcus pentosaceus），1株为类植物乳杆菌（Lactobacillus paraplantarum），1株为副干酪乳杆菌（Lactobacillusparacasei）。通过适当的工艺处理其有望作为乳酸菌添加剂单独或混合添加入青贮中以提高青贮饲料品质。

Filtering of Excellent Lactic Acid Bacteria Strains from Alfalfa Silage

Several strains of lactic acid bacteria （LAB） were isolated from alfalfa （Medicago sativa L.） and the rate of lactic acid production and growth curve were measured. The result showed that 8 strains of LABs had rapid lactic acid-production and the culture medium pH was reduced to below 4.0 in 24h. The 16s rDNA sequence analysis indicated that 4 strains were Lactobacillus plantarum, 2 straisn were Pediococcus pentosaceus,1 strain was Lactobacillus paraplantarum, and another strain was Lactobacillus paracasei. They were expected to apply on silage as microbial additive in the form of individual or mixture to improve the silage quality through the suitable processing.