菌株 TKU033 係以烏賊軟骨為唯一碳/氮源，篩選至台灣三芝土壤經鑑定為 Bacillus cereus之幾丁聚醣酶生產菌。幾丁聚醣酶之較適培養條件為，以含有1.5% 烏賊軟骨粉、0.1%K2HPO4、0.05%MgSO4．7H2O之50mL液態培養基於 37℃搖瓶(150 rpm)培養2天，所得發酵上清液經硫酸銨沉澱、DEAE-Sepharose 及Macro-Prep DEAE Cartidge離子交換樹脂等步驟，純化出一種幾丁聚醣酶。此幾丁聚醣酶之分子量經SDS-PAGE測為43 kDa ，最適反應pH、最適溫度、pH安定性及熱安定性分別為 pH 5、50℃、pH5-7及<40℃，其活性會受 Cu2+ 、Mn2+ 和EDTA所抑制。
較適培養條件所製得B.cereus TKU033粗酵素液，幾丁聚醣酶水解水溶性幾丁聚醣，所得上清液添加於乳酸菌Lactobacillus paracasei 12193及 Lactobacillus kefri 14011的MRS液態培養基，可分別促進乳酸菌生長達141%及116% 之影響。 The chitosanase-producing strain TKU033 was isolated from soil in Taiwan, Sanzhi with squid pen powder 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 optimun pH , optimun temperature, pH stability, and thermal stability of chitosanase were pH 5,
50℃, pH5-7 and <40℃. The chitosanase activity was inhibited by Cu2+ , Mn2+ and EDTA.
The supernatant of the crude enzyme from B. cereus TKU033 hydrolyzed water soluble chitosan exhibited activity of enhancing growth for L. paracasei 12193 up to 141% and L.kefri 14011 up to 116%.
