高产耐热型植酸酶菌株ZJ0702发酵条件优化

Optimization of the Fermention Conditions for Producing Phytase by Heat-resistant Bacillus Nealsonii ZJ0702

目的:对自行分离得到的耐热型植酸酶高产菌株芽孢杆菌ZJ0702发酵条件进行优化,以提高植酸酶的活力。方法:采用单因素试验,研究培养基组分和培养条件对该菌株产植酸酶活力的影响。结果:经优化得到的培养基组分为3.5%麸皮、2%蛋白胨、0.5%硝酸铵、0.01%无机磷、0.2%CaCl_2、0.05%KCl、0.03%MgSO_4、0.003%Fe-SO_4、0.003%MnSO_4、0.03%NaCl;最适培养条件为34℃,接种量7%,pH7.0,装液量75mL/250mL。在上述培养条件下该菌株发酵72h产植酸酶活力达到最高值,为11388.4U/mL。结论:与该菌株在原始条件下产酶活力8251U/mL相比,酶活提高了38%。

Objective：To optimize the fermention conditions of phytase by Bacillus nealsonii ZJ0702 which screened from soil in order to increase its activity.Methods：Effect of the medium components and culture conditions on phytase activity was studied using single-factor test.Results：The optimal fermention medium components（%） were：wheat bran 3.5%,tryptone 2%,KH2 PO4 0.01%,NH4NO3 0.5%,CaCl2 0.2%,KCl 0.05%,MgSO4 0.03%,FeSO4 0.003%,MnSO4 0.003%,NaCl 0.03%;the optimal culture conditions for enzyme-producing were：34 ℃,pH 7.0,inoculum volume 7% and liquid volume in flask 75 mL/250 mL.The phytase activity was up to 11 388.4 U/mL after the strain was cultured for 72 h under the above conditions.Conclusion：The phytase activity was 38% higher under the optimal conditions than that under the premitive conditions （8 251 U/mL）.