一株厌氧角蛋白降解菌的产酶条件优化及其发酵液的应用初探

Condition Optimization for Keratinase Production by Anaerobic Keratinolytic Bacteria Strain KD-1 and the Application of Fermentation Broth

从土壤中分离到一株严格厌氧羽毛角蛋白降解菌KD-1,通过单因素和正交实验研究了角蛋白酶生成的最佳发酵条件。并初步研究了发酵液对种子萌发率和拟南芥根系生长的影响。结果表明角蛋白酶生成的最适培养基为羽毛10 g·L-1,MgSO40.2 g·L-1,尿素2.0 g·L-1,NaCl 3.0 g·L-1,K2HPO43.0 g·L-1,KH2PO42.5g·L-1,培养基初始pH 8.0,培养温度55℃。在最佳培养条件下角蛋白酶酶活可达387U·mL-1KD-1羽毛发酵液中含有脯氨酸、精氨酸、谷氨酸、天冬氨酸、丝氨酸、甘氨酸等16种氨基酸,适当浓度的KD-1发酵液可以促进种子的萌发和植株根系的生长。

Strain KD-1 was an anaerobic keratinolytic bacteria isolated from soil. According to single-factor and orthogonal experiment, the optimum culture medium was feather 10 g L-1 , MgSO4 0.2 g L-1 , urea 2 g L-I , NaC1 3 g L-l , K2 HPO4 3.0 g L-1, KH2 P04 2.5 g L-1. Under the optimum condition of pH 8.0 and 55 ℃, the keratinase activity could reach to 387 U , mL-1. It was detected that there was a variety of amino acids such as proline, arginine, glutamie acid, aspartic acid, serine and glycine in the fermentation broth, which could promote the germination of seeds and the growth of plant root system.