The aim of this study was to select a strain of producing mannase Bacillus,and investigate its effects on growth performance of geese.Congo red plate changing color circle method and assay of enzyme activity method in liquid fermentation were used in screen and rescreen,respectively.Animal safety and gastrointestinal tolerability tests were alse carried out.By morphological observation,physiological and biochemical tests,analysis of complete sequence of 16S rDNA and the phylogenetic tree establishment,species were identified.Bacillus were prepared and added by 0.10％,0.25％,0.50％,0.75％and 1.00％in the geese diets to study its effect on the daily gain and F/G in geese.The results showed that the enzyme activity of the isolated Bacillus subtilis Y-3-2 was 45.939 U/mL,and the strain could also endure pH 2.0 and grow normally in 0.1％cholic acid salt solution and artificial intestinal fluid.The results of feeding test showed that,compared to the control group,the average daily gain of geese increased by 8.78％(P<0.01)and F/G decreased by 6.69％(P<0.01)by adding 0.25％Y-3-2 preparation.In conclusion,adding mannase producing Bacillus could improve the feed utilization and growth of geese.%为了筛选一株产甘露聚糖酶的芽孢杆菌,并考察其对肉鹅生长性能的影响,本试验采用刚果红平板变色圈法进行产甘露聚糖酶芽孢杆菌的初筛,通过液体发酵测定酶活力的方法展开复筛,并进行动物安全性和胃肠道耐受性试验.通过形态特征观察、生理生化试验和16S rDNA全序列分析与发育树构建将其鉴定到种.制备该菌菌剂,并将其按0.10％、0.25％、0.50％、0.75％和1.00％添加于肉鹅日粮中,考察其对肉鹅日增重和料重比的影响.结果表明:筛选到产甘露聚糖酶的菌株枯草芽孢杆菌(Bacillus subtils)Y-3-2,其产酶活力为45.939 U/mL,耐受pH 2.0,在0.1％的胆酸盐溶液和人工肠液中可正常生长.将其制成菌剂,在肉鹅日粮中按0.25％添加,可使试验组肉鹅日增重较对照组提高8.78％(P<0.01),料重比降低6.69％(P<0.01).以上结果说明在肉鹅日粮中添加本试验筛选出的产甘露聚糖酶芽孢杆菌可提高肉鹅的饲料利用率,对肉鹅的生长有显著促进作用.
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