Heterologous Expression And Characterization Of Xylanase And GH61 From Stachybotrys Chartarum In A.Niger

CelluLose and xylan are the most abundant biomass and the most cheap resource. Endoglucanase is the key hydrolases for degradation of celluLose, and so as to xylanase for xylan. For efficiency of hydrolysis of celluLose and xylan, we need get new endoglucanase and xylanase with good properties.In this study, the potential endoglucanase and xylanase genes were found from Stachybotrys chartarum. And then the genes were extracted from their genomic DNA library. With the specific primers designed according to the gene sequences of xya6205 xya4063 and gh2990, fragments of 1699 bp,753 bp and 1353 bp were amplified using the genomic DNA as templates and cloned into pGm vector for sequencing. The sequencing resuLts indicated that the correct DNA fragments were obtained. After being induced by IPTG in A. niger, two recombinant proteins with molecuLar weight of 25 kDa and 48 kDa were successfuLly expressed. The optimal temperature and pH of the xylanase activity was 50℃ and 5.8, respectively. The recombinant enzyme activity reached 392 U/mg by DNS method at optimal condition. The recombinant enzyme remained 83% activity after 18 hr in the alkaline buffer.