一株耐低温纤维素酶高产菌株的筛选、鉴定和产酶的初步试验

从若尔盖高寒湿地距表层80cm处土壤中筛选出一株纤维素酶高产菌株XW-1。根据形态学、生理生化特征以及16SrDNA核酸序列分析结果表明,该菌属于缺陷短波单胞菌(Brevundimonas sp.)。对该菌产酶条件研究表明,XW-1在含0.5%CMC-Na条件下,20°C培养3d后出现最高酶活,达到15.6U/mL。对其酶学性质初步研究表明,该菌株所产纤维素酶的最适pH为6.0,最适反应温度为20°C,15°C时相对酶活达到80%,并且在5°C时,相对酶活仍能保持56%。

Screening and Identification of a Cold-adapted Cellulase-producing Bacteria

Strain XW-1 producing extracellular cellulose was isolated from 80 cm depth under the surface layer at Zoige Plateau Alpine Wetland. It was identified as a Brevundimonas sp. by its morphological, the physiological and biochemical properties and 16S rDNA sequence analysis. The results of cellulose producing research showed that the optimum carbon sourse was 0.5% CMC-Na, the optimum temperature was 20°C. Under this condition, the highest cellulose activity reached to 15.6 U/mL in the third day. Enzymatic properties showed that the optimum pH value is 6.0 and the optimum reaction temperature is 20°C, the relative enzyme activity reach to 80% at 15°C, moreover, at 5°C the relative enzyme activity still reach to 56%.