盐湖微生物Fosmid文库纤维素酶克隆的筛选及产酶研究

Detection of cellulase-producing clones from a microbial fosmid library of salt lake and cellulase-fermented conditions of the clone YH-13

利用平板影印法,从陕西花马盐湖沉积物微生物免培养Fosmid文库4 126个克隆中,筛选到具有羧甲基纤维素酶活性的克隆17个。以纤维素酶活性较强的YH-13号克隆为出发菌株,研究其产酶条件。结果表明,以麦芽糖为最适碳源,以硫酸铵为最适氮源,最适p H值为4.5,最适发酵时间为2 d,最适产酶温度为37℃时该酶活性最高。这为进一步研究利用极端盐湖沉积物微生物纤维素酶基因奠定了基础。

Using the replica plating method,a total of 17 clones with activity of carboxymethyl cellulase were detected from a fosmid library containing 4 126 clones,which was constructed from the microbial metagenomes of the salt lake Huama,Shaanxi. The clone YH-13 were selected to test cellulase-fermented conditions.The optimal cellulase fermentation conditions for the strain YH-13 were as follows： maltose as the optimal carbon source,sodium bicarbonate as the best nitrogen source,the optimal p H value of 4. 5 and the optimal temperature suggested as 36 ℃ for 2 d to reach the highest enzyme activity. These results provide the foundation for further study of microbial cellulase genes in salt lake.