一株具有羽毛降解活性的益生菌的筛选和应用

利用以羽毛为唯一碳氮源的培养基,从市售的益生菌中分离筛选可高效降解羽毛的菌株,发现菌株HUBM2摇瓶培养7d,可将大部分的羽毛降解.该菌株经16SrDNA测序鉴定是地农芽孢杆菌.为缩短降解周期,利用该菌研究不同羽毛预处理方法对羽毛降解效率的影响,发现用0.02％的NaOH溶液处理15 min的羽毛降解效率最高.用稀碱处理的羽毛为唯一碳氮源,从接种量、培养基2个方面对HUBM2降解羽毛的条件进行优化,经过优化后,羽毛降解周期从7d减少到2d,羽毛降解率达到80％.测定降解产物中小肽和益生菌的含量,结果显示,发酵液中益生菌含量为1.4×109 CFU/mL,小肽和氨基酸含量为0.41 mg/mL.

Screening and application of a high efficient feather-degrading probiotics

A high efficient feather-degrading strain HUBM2 was isolated from probiotics products with a culture medium in which feather was used as the unique carbon and nitrogen source.After seven days culture,the feather could be degraded efficiently by probiotics HUBM2.The strain HUBM2 was identified as Bacillus licheniformis based on 16SrDNA sequence analysis.In order to shorten the degrading period,feather were pretreated by different methods to increase the degradation efficiency.The results showed that feather boiled in 0.02% NaOH for 15 minutes was easy to be degraded.With the pretreated feather above,the conditions of feather degradation by HUBM2 were optimized in two aspects of media and inoculum size.The feather degradation cycle reduced from 7 days to 2 days and the rate of feather degradation reached 80%.The content of small peptide and probiotics number in the degradation products was measured.The results showed that fermentation product contained 1.4×109 CFU/mL probiotics and 0.41 mg/mL small peptides.