Cloning and Over-expression of xynB Gene of Bacillus subtilis subsp. spizizenii W23 into Escherichia coli Origami Host Cells

Mariana Wahjudi,Nita Marcelia Wangunhardjo,Xavier Daniel,Ernest Suryadjaja,Catherina

doi:10.18502/kls.v3i5.986

Abstract

The xynB gene of Bacillus subtilis subsp. spizizenii W23 is predicted to encode a xylan 1,4-beta-xylosidase. Application of XynB enzymes in industries is wide. Production of this enzyme in its host cells is naturally restricted by repression process. It will give certain beneficial to over-expressed the enzymes in other host-cells under inducing promoter. This study aimed to clone the xynB gene from Bacillus subtilis subsp. spizizenii W23, to pMMB67EH plasmid, and to over-express the xynB gene in Escherichia coli Origami as host cells. The xynB gene was successfully amplified by polymerase chain reaction (PCR) technique using a pair of primers flanking the gene sequence and chromosomal DNA of the W23 strain as a template. The xynB gene inserted in recombinant plasmid was confirmed by PCR detection using primers pair’s specific for xynB gene and for the vector, then continued by restriction analyses. The result showed that transformants clone 9 and 10 bear the recombinant pMMB-xynB plasmid. The xylanase activity of xynB gene in Escherichia coli Origami clone 10 was detected by sodium-dodecyl-sulfate polyacrylamide gel analyses and with addition of isopropyl-β-D-thio-galactoside (IPTG) as an inducer. The protein seem to be over-expressed as intra- and extra-cellular protein detected on SDS-PAGE gel. Result from xylan degrading activity on Luria-Bertani-xylan-IPTG plate with addition of Congo Red, showed that the cells with pMMB-xynB recombinant plasmid have clear zone around the colonies while the transformant bearing an empty plasmid showed no clear zone. It could be concluded that the xynB gene of Bacillus subtilis subsp.spizizenii W23 has been successfully been cloned on pMMB67EH plasmid and over-expressed in the Escherichia coli Origami cells as intra- and extra-cellular protein, as observed on SDS-PAGE gel analysis. The protein has activity on xylan degradation.

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