响应面法优化厌氧细菌产纤维素酶发酵培养基

通过单因素试验确定了厌氧纤维素降解细菌—溶纤维丁酸弧菌WHQ产纤维素酶的最佳培养条件,结果表明,最适产酶条件为培养时间48h,接种量10％,初始pH值8.5,温度37℃.在此基础上,应用响应面法优化该菌株产纤维素酶培养基.在初期研究中,葡萄糖和尿素确定为最佳的碳氮源,利用Plackett-Burman设计从10种培养基成分中筛选出对WHQ产内切纤维素酶有重要性的因素,结果表明葡萄糖、NaHCO,和MgSO4·7H2O对WHQ产内切纤维素酶有重要影响,利用Box-Behnken设计研究这3种因素对WHQ产内切纤维素酶的综合效应,结果表明3种因素的最佳值为MgSO4·7H2O 0.14g/L、葡萄糖14.3g/L、NaHCO3 6.92g/L,此时的内切酶酶活力最大值为206.548μg/(mL.min),与实验值相接近199.324μg/(mL·min),比未优化前的内切纤维素酶活力71.254μg/(mL·min)提高179％.

Optimization of fermentation medium for cellulase production by anaerobic bacteria using response surface methodology

In the present study, the optimal culture conditions of ceUulase production by an aerobic cellulolytic bacteria-Butyrivibrio fibrisolvens WHQ was investigated by using Single-factor experiment. The optimal conditions were as followed： culture time 48h, inoculum 10%, initial pH 8.5 and culture temperature 37℃. Based on these results, the response surface methodology was applied to investigate the optimal cellulase production medium. In our previous study, glucose and urea were determined as the optimal carbon sources and nitrogen source, respectively. 10 kinds of medium compo- nents were examined using Plackett-Burman factorial design. The result showed that glucose, NaHCO3 and MgSO4 · 7H2O have significant effect on the endo-cellulase production. The optimal concentrations were as followed： MgSO4·7H20 0.14g/L, glucose 14.3g/L and NaHCO3 6.92g/L, respective-ly. The maximum endo-cellulase activity was 206.5481μg/（ml·min） under optimal condition and medium, which was close to the experimental deter-mined value 199.3241μg/（ml-min）. This endo-cellulase activity was increased by 179% compared with that of before optimization 71.2541μg/（ml-min）.