Bacillus cereus TKU044 係篩選自花蓮土壤之幾丁聚醣酶生產菌，以含有1%烏賊軟骨粉、0.1% K2HPO4、0.05% MgSO4．7H2O之100 mL液態培養基，於37℃進行搖瓶 (150 rpm)培養2天後，可得較高幾丁聚醣酶活性 (2.66U/mL)。 培養所得發酵上清液經硫酸銨沉澱、DEAE-Sepharose 及 Macro-Prep® DEAE Cartridge 陰離子交換層析等步驟，以285.9倍之純化度以及16%之回收率，純化出經 SDS-PAGE電泳測得分子量約為43 KDa 之一種幾丁聚醣酶。此幾丁聚醣酶的最適反應pH為7，pH安定性為6~7，最適反應溫度為40℃，而熱安定性則是低於50℃，其活性會受到Na+、Fe2+、Ba2+、Cu2+、Zn2+及EDTA所抑制。TKU044粗酵素液水解水溶性幾丁聚醣所得寡糖，具有抗氧化活性。 The chitosanase-producing strain TKU044 was isolated from the soils of Hualien with squid pen power (SPP) as the sole carbon/nitrogen source and identified as Bacillus cereus. A chitosanase was purified from the culture supernatant by ammonium sulfate precipitation, DEAE-Sepharose and Macro-Prep® DEAE Cartridge. The molecular mass of chitosanase determined by SDS-PAGE was approximately 43 kDa. The optimum pH, optimum temperature, pH stability, and thermal stability of the TKU044 chitosanase were pH 7, 40℃, pH 6~7 and under 50℃, respectively. The chitosanase activity was inhibited by Na+, Fe2+, Ba2+, Cu2+, Zn2+ and EDTA. The oligosaccharides prepared by hydrolyzing soluble chitosan with the crude chitosanase showed antioxidant activity.
