【摘要】 该研究从连云港海域海泥中筛选产右旋糖酐酶菌株,对其进行形态学观察、生理生化试验及分子生物学鉴定,并对其产右旋糖酐酶的酶学性质、酶解产物组分及抗氧化活性进行研究。结果表明,筛选得到一株产右旋糖酐酶菌株GN02,其被鉴定为芽孢杆菌（Bacillussp.）。菌株GN02产右旋糖酐酶的最适温度和pH分别为20℃和7.0,在25～40℃、pH5.0～9.0范围具有良好的稳定性。酶解1h的主要产物为异麦芽四糖（85.6%）和异麦芽三糖（14.3%）。酶解产物清除羟基自由基、1,1-二苯基-2-三硝基苯肼（DPPH）和超氧阴离子自由基的半抑制浓度(IC₅₀值)分别为0.42mg/mL、2.98mg/mL和11.54mg/mL。更多还原

【Abstract】 Dextranase-producing strain was screened from the sea mud of Lianyungang sea area, and identified by morphological observation, physiological and biochemical tests and molecular biology. The enzymatic properties, enzymatic hydrolysis product components and antioxidant activities of the dextranase produced by the strain were studied. The results showed that a dextranase-producing strain GN02 was screened and identified as Bacillus sp. The optimal temperature and p H of the dextranase produced by the strain GN02 were 20 ℃ and 7.0, respectively. The enzyme had good thermal stability in the range of 25-40 ℃ and p H 5.0-9.0. The main products of enzymatic hydrolysis for 1 h were isomalttetraose(85.6%) and isomaltotriose(14.3%). The 50%inhibiting concentration(IC50 value) of the enzymatic hydrolysis products to scavenge hydroxyl radical, 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical and superoxide anion radical were 0.42 mg/ml, 2.98 mg/ml and 11.54 mg/ml, respectively.更多还原