利用木聚糖酶选择培养基，从120株标准芽胞杆菌中筛选出37株能够形成明显透明圈的芽胞杆菌。经产酶发酵液培养基复筛，得到1株木聚糖酶活性较高的菌株FJAT-14260（沙福芽胞杆菌 Bacillus safensis）。采用单因素实验设计和正交实验设计进行优化，结果表明，在培养基优化中对产酶影响最大的因素是底物浓度；在发酵条件优化中对产酶影响最大的因素是培养温度。优化得到FJA T-14260的最佳产酶发酵条件为：碳源（酵母粉）7g·L -1，氮源（蛋白胨）9g·L -1，底物（木聚糖）浓度10g·L -1，培养温度30℃，初始pH值8，装液量30 mL/250 mL。在此条件下FJAT-14260在发酵32 h时酶活力达到113585.78 U · mL -1，比优化前提高了4.62倍。%Selective medium for xylanase was used in screening the xylanase producing Bacillus strains . Thirty-seven of the 120 Bacillus strains tested were found to form transparent circles on the plates . After a secondary screening with the enzyme fermentation medium ,B . safensis FJAT-14260 was determined to be the most desirable strain for the xylanase production . A single factor and an orthogonal experiment were used to optimize the fermentation conditions . The results showed the substrate concentration to be the most important factor relating to the medium ,and temperature ,the most critical condition for the fermentation process . In all ,the best medium for the enzyme production consisted of carbon source (yeast extract) at 7 g · L -1 ,nitrogen source (peptone) at 9 g · L -1 ,and substrate (xylan) at 10 g · L -1 . And ,the optimal fermentation temperature was 30℃ ,initial pH at 8.0 , and liquid volume at 30 mL/250 mL . Under these conditions ,after allowing FJAT-14260 to ferment for 32 h ,the xylanase activity could reach as high as 113 585.78 U · mL -1 ,which was 4.62 times of what was without the optimization .
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