西藏地区牦牛瘤胃中兼性厌氧纤维素降解菌的分离鉴定

发布时间：2018-03-24 15:50

  本文选题：牦牛　切入点：瘤胃液　出处：《草业学报》2017年06期

【摘要】：本研究旨在从西藏地区牦牛瘤胃中分离出具有分解纤维素能力的兼性厌氧菌,为青贮饲料微生物添加剂的研制提供支持。试验采集了西藏那曲地区成年牦牛的新鲜瘤胃液,经刚果红染色初筛,滤纸降解复筛,获得分解纤维素能力强的菌株,对菌株生长速率及酶活力进行测定,经形态学、生理生化特性和16SrRNA序列分析对菌株进行鉴定,并分析了菌株对水稻秸秆的降解效果。试验分离出一株兼性厌氧纤维素降解菌,属于肠球菌属,即粪肠球菌(Enterococcus faecalis)JF85。菌株JF85在15~55℃,pH 3.0~7.0及3.0%和6.5%NaCl培养基中生长良好。接种JF85,36h后可获得最大内切葡聚糖酶活力(0.41U/mL)和滤纸酶活力(0.13U/mL)。在模拟发酵试验中,接种菌株JF85,14d后水稻秸秆干物质、纤维素和半纤维素含量与对照组相比显著降低(P0.05);在发酵第7天,JF85处理组显示最高的可溶性碳水化合物含量,整个发酵过程中木质素含量变化不显著(P0.05)。菌株JF85具有分解纤维素、耐酸、耐盐特性,在青贮饲料生产中具有较好的应用前景。
[Abstract]:The purpose of this study was to isolate facultative anaerobes with cellulolysis ability from the rumen of yak in Tibet, and to provide support for the development of microbial additives for silage. The fresh rumen fluid of adult yaks in Naqu region, Tibet, was collected. The strain with strong ability to decompose cellulose was obtained by primary screening with Congo red staining and double screening by filter paper degradation. The growth rate and enzyme activity of the strain were determined. The strains were identified by morphological, physiological and biochemical characteristics and 16SrRNA sequence analysis. A facultative anaerobic cellulose degrading strain was isolated, which belongs to Enterococcus. That is, Enterococcus faecalisus JF85.The strain JF85 grew well in the medium of pH 3.0, 7.0 and 3.0% and 6.5%NaCl at 1555 鈩，

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