Abstract: The purpose of this study is to isolate and identify salt-tolerant lactic acid bacteria (LAB) in Spartina anglica Hubb. and analyze its effect on the quality of the grass silage. The salt-tolerant LAB strains were identified by morphology,physiological and biochemical and 16S rDNA sequence analysis methods. Then,the silage of Spartina anglica Hubb. were made by adding the salt-tolerant LABs. The results showed that 4 out of 42 LABs isolated from Spartina anglica Hubb. could tolerant 10% salt. They were homofermentative L.plantarum and named C1,C2,C3 and C4. Compared to the control,four LAB strains improved the silage fermentation quality (P<0.05). The contents of water soluble-carbohydrate and ether extract were significantly (P<0.05) increased,and the ammonia nitrogen content was significantly (P<0.05) decreased by C1,C2,C3 and C4 treatments. When treated with C4,the dry matter content and lactic acid content in silage were significantly higher (P<0.05),and the contents of neutral detergent fiber,acid detergent fiber,hemicellulose,and butyric acid in silage were significantly lower (P<0.05) than that treated with C1,C2 and C3.

Key words: Spartina anglica Hubb., Salt-Tolerant, Lactic acid bacteria, Identification, Silage

摘要： 本试验旨在研究大米草（Spartina anglica Hubb.）中耐盐乳酸菌的分离鉴定及对大米草青贮品质的影响，以期为大米草青贮利用提供技术支持和理论依据。试验采用传统培养法筛选出耐盐浓度为10%的乳酸菌菌株，通过生理生化及16S rDNA序列分析法综合鉴定筛选的菌株，并将其添加到大米草原料中进行青贮效果观察。结果表明：分离获得的42株乳酸菌菌株，耐盐溶度最高为10%的4株乳酸菌均为同型发酵的植物乳杆菌（Lactobacillus plantarum），命名为C1、C2、C3和C4。4株乳酸菌均能提高大米草的青贮发酵品质，其中C4显著提高青贮料的可溶性碳水化合物和粗脂肪含量（P<0.05），显著降低青贮料的氨态氮含量（P<0.05）；另外，C4处理组的干物质含量和乳酸含量显著高于其他3个菌株处理组（P<0.05），中性洗涤纤维、酸性洗涤纤维、半纤维素和丁酸含量显著（P<0.05）低于其他3个菌株处理组，青贮效果最佳。

关键词: 大米草, 耐盐, 乳酸菌, 鉴定, 青贮