壳聚糖酶高产菌株的筛选和发酵条件的研究

Screening of a Chitosan-Hydrolytic Bacterium and Research on Its Fermentation Conditions

从采集的土样中分离到1株产壳聚糖酶能力较强的菌株OU01,并对OU01进行了16S rDNA序列、形态及生理生化鉴定分析。16S rDNA序列分析表明该菌属于微杆菌属;该菌的形态特征与生理生化鉴定结果表明该菌与Microbacteriumsp.的相似性最高;因此将其初步鉴定为微杆菌属(Microbacterium)。同时对该菌的发酵条件进行了初步研究:该菌的最适培养基组成为(g/L):chitosan 10,(NH4)2SO420,MgSO4.7H2O 1.3,K2HPO4.3H2O 1.4,Glucose 1,Yeast extract 3,NaCl 5,起始pH=6.30。最适发酵温度为30℃,最佳发酵时间为96 h,在上述最优条件下,该菌株产酶达到118 U/mL。Microbacteri-umsp.OU01菌株为壳聚糖酶的研究和应用提供了新的来源。

A chitosanase-producing bacterium was isolated from soil through selective enrichment culture and named as OU01. The strain OU01 was identified by 16S rDNA sequence, morphological, biochemical and physiological identification. The sequence data aligned with 16S rDNA sequences deposited in GenBank indicate that the strain OU01 belonged to the genus of Microbacterium and the morphological, biochemical and physiological characteristics also showed that the strain OU01 belonged to Microbacterium sp.. The optimum medium composition for producing chitosanase by Microbacterium sp. OU01 was as follows （g/L） ： chitosan 10, （NH4）2SO4 20, MgSO4·TH2O 1.3, K2HPO4 3H2O 1.4, Glucose 1, Yeast extract 3, NaCl 5, the initial pH 6.3. The optimum cultivation condition for producing chitosanase by Microbacterium sp. OU01 was to incubate in flask at 30 ℃ , 150 r/min for 96 h. The maximal chitosanase activity could reach 118 U/mL when Microbacterium sp. OU01 was incubated in flask under the optimum cultural conditions. The strain Microbacterium sp. OU01 provides a new source for the study and application of chitosanase.