匍枝根霉液态发酵产木聚糖酶培养基优化研究

Investigation of cultural optimization of xylanase production by Rhizopus stolonifer liquid fermentation

利用响应面法对匍枝根霉液态发酵产木聚糖酶的培养基进行优化研究.采用单因素实验,得到最佳的碳源、氮源、无机盐.采用Plackett-Burman对影响匍枝根霉产木聚糖酶发酵的相关因素进行评价,确定有显著效应的3个因素.采用最陡爬坡实验确定接近响应值区域显著因素的浓度,利用3因素3水平的Box-Behnken实验进行培养基优化.结果表明,培养基组成:3.9%麦麸玉米芯粉混合碳源,0.35%(NH4)2SO4,0.2%KH2PO4,0.2%MgSO4·7H2O,0.4%CaCl2,0.06%吐温-80,1%微量元素液,装液量为100mL,pH自然,接种量为10%,在30℃,180r/min条件下培养,其木聚糖酶酶活达到最高为101.697U/mL,比优化前木聚糖酶酶活提高了3.5倍.

Using the response surface method and single {actor experiment to optimize the xylanase produ- cing medium of Rhizopus stolonifer,the optimal carbon source,nitrogen source,and inorganic salt were obtained. To evaluate the influence of related factors of Rhizopus stolonifer filiferus xylanase fermenta- tion,Plackett-Burman method was employed to identify three factors which have significant effects. The steepest ascent experiment was used to determine the concentration of near-response-value regional sig- nificant factors,and the three-factor-three-level Box-Behnken experiment was used to optimize the medi- um. The results showed that the optimal medium composition were as follows. 3.9% wheat bran, corn- cob powder mixed carbon sources,0. 35% （NH4）2SO4,0. 2%＂ KHzPO4,0.20//00 MgSO4 7H20,0. 4% CaC12,0.06% Tween-80, 1% trace element solution, liquid volume was 100 mL, with native pH. With inoculation amount 10%, shaking at 30 ℃ with speed 180 r/min, the culture reached the highest xyla- nase activity.101. 696 3 U/mL. The optimized xylanase activity was 3.5 times higher than before.