酸性木聚糖酶高产菌株的筛选及其液体发酵产酶条件优化

Screening of Acid-xylanase High-yield Strain and Its Improvement of Xylanase Production in Liquid-state Fermention

为了获得能够利用玉米芯等农业废弃物作为碳源的酸性木聚糖酶高产菌株,降低产酶成本,对全国各地300余份土样进行了菌株筛选,获得1株以玉米芯作为碳源产酸性木聚糖酶青霉菌,菌株编号MA21601,初测该菌株所产木聚糖酶最适作用pH值范围4.0-4.5。通过对该菌株液体发酵条件优化,确定其最佳产酶条件是：60 mg/mL玉米芯,1.5 mg/mL硫酸铵,培养基初始pH值3.0-3.5,发酵温度25℃,转速125 r/min;发酵液终pH 1.27。菌株产酶趋势研究表明：菌株发酵第7天产木聚糖酶酶活力达到1 808 U/mL,是初筛酶活的361.6%。

The potential application of acid-xylanase in industry has attracted more and more attention in recent years, in order to obtain high-level acid-xylanse produced strains, screening of acid-xylanase produced strains from soil by plate screening method was carried out in this study. Strain of Penicillium MA21601 which can produce acid-xylanase using corncob as carbon source was obtained. The influence of several factors on xylanase production from Penicillium MA21601 was evaluated by liquid-state fermention. Maximum xylanase activity was observed in the presence of 6% corncob and 1.5% ammonium sulphate was the most appropriate inorganic nitrogen source for xylanase production. And the maximum xylanase activity of 1 808 U/mL was obtained after cultivating for 7 days. Medium optimisation for the acidic Penicillium, strain MA21601, resulted in a 3.62-fold increase of extracellular xylanase activity.