高产壳聚糖酶菌株的筛选和发酵产酶条件研究

Screening of Chitosanase-Producing Strain and Research on Its Fermentation Conditions

为探讨专一性地降解甲壳质或壳聚糖的甲壳质酶或壳聚糖酶 ,从采集的土样中分离到 4株产壳聚糖酶能力较强的菌株 ,经摇瓶复筛 ,菌株YJ0 2产酶能力最强。对其发酵产酶条件的研究结果表明其产酶最适培养基组分为 (% ,w/v) :粉末壳聚糖 2 .0 ,葡萄糖 0 .1,NH4NO3 1.0 ,酵母提取物 0 .5 ,K2 HPO40 .0 7,KH2 PO40 .0 3 ,NaCl0 .5 ,MgSO4·7H2 O 0 .0 5 ,起始 pH 6.0。最适产酶培养条件是 :5 0 0mL三角烧瓶装瓶量为 15 0mL ,2 .0 % (v/v)接种量 ,3 0℃ ,15 0r/min培养 72h。在最适产酶培养条件下 ,72h时菌株YJ0 2发酵液中壳聚糖酶活力可达到 17.0 4U/mL。

Four strains producing chitosanase were isolated from soil samples. Shaking cultivation demonstrated that the strain named YJ02 possessed the highest chitosanolytic activity. The optimal composition of medium for YJ02 producing chitosanase was as follows(%,w/v): powder chitosan 2.0, glucose 0.1, NH 4NO 3 1.0,yeast extract 0.5, K 2HPO 4 0.07,KH 2PO 40.03,NaCl 0.5,MgSO 4·7H 2O 0.05,the initial pH^6.0. The optimal cultivation conditions for YJ02 producing chitosanase were 500mL flask containing 150mL medium, 2%(v/v)amount of inoculation , 30℃ incubating temperature and shaking cultivation at 150r/min for 72 hours. The maximal chitosanase activity could reach 17.04U/mL when YJ02 was incubated in flask under the optimal cultural conditions.