羽毛降解菌的分离鉴定及角蛋白酶基因克隆

Isolation and Characterization of a Feather-degrading Bacterium and Cloning of Keratinase Gene

为了从废弃羽毛堆积土壤中分离筛选具有高效降解羽毛角蛋白的细菌,采用形态学观察、生化测定和16S rDNA序列分析鉴定菌株,测定蛋白水解研究酶活性及酶特性,鉴定该菌为假单胞菌属的嗜麦芽窄食单胞菌,降解羽毛的最适发酵培养温度为30℃,最适pH 7.0,最适接种量1%,最适发酵时间48 h,羽毛含量在0.25~0.5 g/50m L时产酶酶活性最高且较稳定,适合降解羽毛和头发。嗜麦芽窄食单胞菌角蛋白酶的作用温度和pH宽泛、稳定性好,具有良好的开发价值和应用前景。

This study was aimed to isolate and characterize feather-degrading bacteria from soil of discarded feathers. Morphological observation, biochemical analysis and 16S rDNA sequence analysis were used for identifying bacteria, and the enzyme activity and enzyme properties was studied by mensurating protein hydrolysis. The strain was identified as genus Pseudomonas, Stenotrophomonas maltophilia. The optimal pH and temperature for growth were 7.0 and 30℃, optimal inoculum size is 1 %, optimal fermentation time is 48 b. The enzyme activity was highest and stable when the feather content was 0.25-0.5 g/50mL. The keratinase gene was cloned which included complete sequence of 2 157 bp and a 1 734 bp open reading frame encoded 580 amino acids from Stenotrophomonas maltophilia. Keratinase of Stenotrophomonas maltophilia has the potential for the application of feather keratin sources for the functional temperature and pH is broad and stable.