一株琼胶降解菌的筛选、鉴定及粗酶学性质

本研究通过初筛、复筛从青岛近海沉积物中分离出一株具有琼胶酶活性的菌株,该菌的最佳发酵时间为26 h,对该菌培养基进行卢戈氏碘液染色后菌落周围出现明显透明圈,镜检观察菌株的革兰氏染色结果表明,该菌为革兰氏阴性菌。经过鉴定,该菌株为不动杆菌（Acinetobacter sp.）,命名为Acinetobacter sp.LXK,对该菌的粗酶学特性进行初步研究,结果显示,该酶的最适反应温度为40℃,最适底物浓度为0.5%,最适反应体系p H为8.0,K⁺和Ca²⁺对酶解反应有促进作用,Fe²⁺、Mn²⁺和Ba²⁺对酶解反应有不同程度的抑制作用。 

Isolation,identification and enzymology properties of an agarase-producing strain

An agar-decomposing strain was isolated from Qingdao offshore deposits. The optimal fermentation time was 26 h, transparent zones appeared after staining with lugol 's iodine. The bacteria was gram-negative and classified in the genus Acinetobacter, named as Acinetobacter sp.LXK.By studying the primary properties of agarase and study showed that: the optimal p H and temperature for enzymolysis were p H8.0 and 40 ℃ respectively, the optimum concentration of substrate was 0.5%, the enzyme was activate by K⁺, Ca² +and inhabited by Fe ⁽2+）, Mn^（2+）, Ba^（2+）.