一株地衣芽孢杆菌脲酶生产的发酵优化和酶学性质

The Urease Fermentation Optimization of a Urease-producing Bacillus Licheniformis Strain

对中国南海海绵Halichondria regosa中分离得到脲酶产生菌Bacillus licheniformis B81进行脲酶生产的发酵条件优化;并对其脲酶特性进行测试。通过对基础培养基筛选后,对选定基础培养基进行了Plachett-Bunman重要因素筛选,最终选定的重要因素通过单因素实验得到了最终的培养基配方为:葡萄糖25 g/L,蛋白胨12.5 g/L,牛肉膏5 g/L,酵母粉6.5 g/L,KH2PO42 g/L,NaCl 1 g/L,尿素0.625%(W/V),Ni(NO3)20.006 25%(W/V),H2O 1 L。优化后,使得脲酶的产量提高到了原培养基的170%。菌株所产生的脲酶的最适反应pH为7.0,最适温度为40℃,Pb2+、Cu2+对脲酶活性具有抑制作用。

Bacillus licheniformis strain, named B81 which could produce urease was separated from sponge Halichondria regosa. Using fermentation optimized methods Plachett-Bunman to choose the important factor of the basal medium, then the single factor experiment was used to optimize the urease production, the optimized medium was ：glucose 25 g/L,peptone 12.5 g/L,beef-extracts 5 g/L,Yeast extract 6.5 g/L,KH2PO4 2 g/L,NaCl 1 g/L, urea 0. 625% （ W/V）, Ni（ NO3 ） 2 0. 00625% （W/V） , H2O 1 L. Urease activity increased 170% in the optimum medium. The urease reacted best at 40 ℃ and pH7.0, and had activities 〉 90% after 30 min maintenance under 50 ℃ and pH7.0, and was sensetive for mental ion, such as Pb2＋ and CuE.