枯草芽胞杆菌乙酰木聚糖酯酶的鉴定及诱导剂对酯酶活力的影响

以枯草芽胞杆菌CICC 20034为研究对象,对其分泌的高相对分子质量酯酶进行鉴定,并考察诱导剂对其活力的影响。结果表明:枯草芽胞杆菌CICC 20034可分泌一种相对分子质量为1.07×105的酯酶,经蛋白质质谱鉴定为乙酰木聚糖酯酶,单体分相对子质量为3.56×104。在发酵培养基中添加乙酸乙酯和木糖可以显著的促进乙酰木聚糖酯酶的活力,而三丁酸甘油酯和大分子诱导剂——木聚糖、玉米芯粉和壳聚糖对酯酶的活力几乎无促进作用。枯草芽胞杆菌CICC 20034以乙酸乙酯为诱导剂时最高比酶活为0.62 U/mL,为已知报道的野生细菌乙酰木聚糖酯酶的最高酯酶活力。

Identification of acetyl xylan esterase from Bacillus subtilis and effects of inducers on its production

An acetyl xylan esterase from Bacillus subtilis CICC 20034 was identified and the effects of inducers on its production were evaluated. The results showed that Bacillus subtilis CICC 20034 secreted 1.07 × 105 of high-molecular-weight esterase, the esterase was identified as an acetyl xylan esterase via mass spectrometry, and molecular weight of the subunit of the esterase is 3.56 ×104. Adding ethyl acetate and xylose as inducers into fermentation medium extremely increased the production of acetyl xylan esterase, however, other inducers, such as tributyrin, xylan, corncob powber and chitosan showed had no effects on the esterase production. The activity of acetyl xylan esterase of Bacillus subtilis CICC 20034 reached 0. 62 U/mL using ethyl acetate as an inducer, thus it is the highest activity level among wild bacterial acetyl xylan esterase production strains.