金龟子绿僵菌固态发酵产壳聚糖酶

Production of chitosanase by Metarhizium anisopliae in solid state fermentation

对金龟子绿僵菌（Metarhizium anisopliae）AS3．4606产壳聚糖酶进行了固态发酵条件优化及酶学部分特征的研究。正交实验结果表明，以麸皮为碳源，日本根霉菌丝体粉末为氮源，在起始pH5．0，m（碳）：m（氨）为1：4，m（干重）：m（液体）为1：1．4，27℃下培养120h，壳聚糖酶活性可达35．08U／g（干培养基）。粗酶液的最适反应温度为40℃，最适反应pH为5．0，酶在pH5．0～6．0条件下稳定性最高。该酶不能水解固体甲壳素和纤维素粉末，最适底物为胶体壳聚糖。

Study on production of chitosanase and partial enzymatic properties of Metarhizium anisopliae AS3. 4606 in solid-state fermentation was conducted. Resuts of the orthogonal experiments indicated that the optimal medium consisted of bran and mycelium powder of Rhizopus japonicus powder at carbon/nitrogen ratio of 1 ： 4. The enzyme activity reached 35.08 units per gram dry medium after cultured for 120 hours at 27 ℃ and an initial pH 5.0. The optimal temperature and pH for the chitosanase production were 40℃ and pH 5.0, respectively. The enzyme couldn＇t degrade flaked chitin, the most susceptible substrate was 90% deacetylated colloid chitosan.