Oligosaccharides have important alimental and medical applications. Dextranase has been used to produce isomalto-oligosaccharides (IMOs). In this study, we isolated dextranase-producing bacteria from sugarcane-cultivated soil. Identification of the isolate based on its phenotypical, physiological, and biochemical characteristics, as well as 16S ribosomal deoxyribonucleic acid gene sequencing yielded Shewanella sp. strain GZ-7. The molecular weight of the dextranase produced by this strain was 100-135 kDa. The optimum temperature and pH for dextranase production were 40 °C and 7.5, respectively. The enzyme was found to be stable at the pH range of 6.0-8.0 and the temperature range of 20 °C-40 °C. Thin-layer chromatography and high-performance liquid chromatography of the enzymolysis products of the substrate confirmed the enzyme to be endodextranase. Under the optimal conditions, the ratio of IMOs could reach 91.8% of the hydrolyzate. The final products were found to efficiently scavenge the 2,2-diphenyl-1-picrylhydrazyl, hydroxyl, and superoxide anion radicals. In general, dextranase and hydrolyzates have high potential prospects for application in the future.

寡糖具有重要的营养和医学应用。葡聚糖酶已用于生产异麦芽寡糖（IMOs）。在这项研究中，我们从甘蔗栽培的土壤中分离出产生葡聚糖酶的细菌。根据其表型，生理和生化特征以及分离的16S核糖体脱氧核糖核酸基因测序鉴定出希瓦氏菌sp。菌株GZ-7。该菌株产生的葡聚糖酶的分子量为100-135kDa。葡聚糖酶生产的最佳温度和pH分别为40°C和7.5。发现该酶在pH范围6.0-8.0和温度范围20℃-40℃下稳定。底物的酶解产物的薄层色谱法和高效液相色谱法证实该酶为内切葡聚糖酶。在最佳条件下，IMO的比例可以达到水解产物的91.8％。发现最终产物可有效清除2，2-二苯基-1-吡啶甲基肼基，羟基和超氧阴离子自由基。通常，葡聚糖酶和水解产物在未来的应用中具有很高的潜在前景。