大米草中耐盐乳酸菌的分离鉴定及对大米草青贮品质的影响

Isolation and Identification of Salt-Tolerant Lactic Acid Bacteria in Spartina anglica Hubb.and Its Effect on the Quality of Silage

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。

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.