Life Science Development Center, Tamkang University, New Taipei City 25137, Taiwan.
Carbohydr Polym. 2012 Oct 15;90(3):1305-13. doi: 10.1016/j.carbpol.2012.06.077. Epub 2012 Jul 4.
Two chitinases, Chi I and Chi II, were purified from the culture supernatant of Bacillus cereus TKU027 with shrimp head powder (SHP) as the sole carbon/nitrogen source. The molecular masses of Chi I and Chi II determined using SDS-PAGE were approximately 65kDa and 63kDa, respectively. Chi I toward various surfactants showed high stability, such as SDS, Tween 20, Tween 40 and Triton X-100, and these surfactants were stimulator of Chi I chitinase activity. Concomitant with the production of Chi I and Chi II, chitin oligosaccharides were also observed in the culture supernatant, including chitobiose, chitotriose, chitotetrose and chitopentose at concentrations of 0.44mg/mL, 0.08mg/mL, 0.09mg/mL and 0.43mg/mL, respectively. Chitosan with 60% deacetylation was degraded by TKU027 crude enzyme to prepare chitooligosaccharides. MALDI-TOF MS analysis of the enzymatic hydrolyzates indicated that the products were mainly chitooligosaccharides with degree of polymerization (DP) in the 4-9 range.
从以虾头粉为唯一碳氮源的蜡状芽孢杆菌 TKU027 的发酵液中分离得到了两种几丁质酶 Chi I 和 Chi II。SDS-PAGE 测定 Chi I 和 Chi II 的分子量约为 65 kDa 和 63 kDa。Chi I 对 SDS、Tween 20、Tween 40 和 Triton X-100 等各种表面活性剂表现出很高的稳定性，这些表面活性剂是 Chi I 几丁质酶活性的刺激物。伴随着 Chi I 和 Chi II 的产生，在发酵液上清中也观察到了几丁寡糖，包括浓度分别为 0.44mg/mL、0.08mg/mL、0.09mg/mL 和 0.43mg/mL 的壳二糖、壳三糖、壳四糖和壳五糖。用 TKU027 粗酶将脱乙酰度为 60%的壳聚糖降解制备几丁寡糖。MALDI-TOF MS 分析酶解产物表明，产物主要是聚合度（DP）在 4-9 范围内的几丁寡糖。
