对实验室自行分离得到的芽孢杆菌ZJ0702发酵生产植酸酶的条件进行优化,以提高植酸酶的产量.利用2-Level Factorial试验筛选出对产酶显著影响的3个因素,通过最陡爬坡试验确定中心点,再采用Central Composite设计对重要因子进行优化.结果发现麸皮、蛋白胨和KH2PO4的添加量是影响植酸酶产量的显著因素,经优化后的培养基组分为3.7%麸皮,2.27%蛋白胨,0.5%硝酸铵,0.008 63%无机磷,0.2%CaCl2,0.05%KCl,0.03%MgS04,0.003%FesO4,0.003%MnSO4,0.03%NaCl;培养条件为:34℃,接种量7%,pH7.0,摇瓶装液量75 mL/250 mL,在上述条件下该芽孢杆菌84 h产酶达到最高值13 625.8 U/mL,与优化前菌株产酶活力相比,酶活提高了19.6%.%The fermentation conditions for producing phytase by Bacillus subtilis ZJ0702 were optimized in order to enhance its activity. Three factors influencing phytase activity significantly were screened by 2 - level factorial experiment, the central point was determined by the steepest ascent experiment and the optimal fermentation conditions were established by central composite design. The results indicated that wheat bran, tryptone and KH2PO4 were the three main factors which have an obvious effect on the phytase activity. The optimal fermentation medium components were: wheat bran 3.7％, tryptone 2.27％, KH2PO4 0.008 63％, NH4NO3 0.5％, CaCl2 0.2％, KCl 0.05％, MgSO4 0.03％ ,FeSO40. 003％, MnSO4 0.003％ ,NaCl 0.03％; the optimal enzyme- producing conditions were :34 ℃ ,inoculum volume 7％ ,pH 7.0 ,liquid volume in flask 75 mL./250 mL. Under these conditions,phytase activity was up to 13 625.8 U/mL after Bacillus subtilis was cultured for 84 h,which was 19.6％ higher comparing with that before optimization.
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