低温纤维素酶产生菌的筛选、鉴定及酶学性质初步研究

Screening and Identification of A Cold-adapted Cellulase-producing Strain and Characterization of Cellulase

从连云港高公岛海域采集海水和海泥样品,通过2216E平板初筛和摇瓶发酵复筛,得到一株产纤维素酶的菌株Z6。对该菌生物学特性进行研究,菌株Z6为革兰氏阴性杆状细菌、有荚膜、无芽孢。菌的生长温度范围为4～35℃,最适生长温度为25℃;最适生长pH为8;最适NaCl浓度为3%。根据其形态特征、生理生化特性和16SrRNA序列分析结果,初步鉴定为交替假单孢菌属(Pseudoalteromonassp.)。根据菌株16SrRNA同源性和系统进化树分析进一步鉴定菌株Z6属于Pseudoalteromonas carrageenovora。目前尚无Pseudoalteromonas carrageenovora产生低温纤维素酶的报道。菌株Z6所产纤维素酶的最适作用温度和pH分别为30℃和pH8,在10℃仍具有较高活性,具有较大的潜在工业应用价值。

Swain Z6 producing extracellular cellulase was isolated from seawater and sea mud collected from the Gaogong island of Lianyungang seaside. Its cell was rod shaped and gram-negative, with capsule and non-sporeforming. The fit range of growth temperature was 4- 35 ℃, and the most suitable one was 25 ℃. The optimum pH for its growth was at pH8. The most suitable concentration of NaCl was 3%. The preliminary identification indicated that the strain belonged to Pseudoalteromonas sp. according to its morphological, the physiological and biochenaical properties and 16SrRNA sequence analysis. Sequencing and phylogenetic analysis of the 16S rRNA gene of strain Z6 indicated that the strain belonged to Pseudoalteromonas carrageenovora. No work on Pseudoalteromonas carrageenovora producing cold-adapted cellulase had been reported so far. The optimal temperature and optimal pH for the cellulase produced by strain Z6 were 30℃ and 8.0 respectively. The cellulase still kept high activity at 10 ℃. It might have a potential value of industrial application.