Expression of a thermostable xylanase gene from Bacillus coagulans ST-6 in Lactococcus lactis.
OBJECTIVE
The aim of the study is to evaluate whether xylanase can be used as a potential reporter gene for cloning and expression studies in Lactococcus.


RESULTS
The 750 bp xylanase gene was amplified and subcloned into the unique NheI restriction enzyme site of pMG36e and subsequently transformed into competent Escherichia coli XLI-blue MRF cells and Lactococcus lactis cells. Bacterial culture containing pMG36e-Xy has an enzyme activity of 390 microg xylose ml(-1) culture 30 min(-1), respectively, when compared with 40 microg xylose ml(-1) culture 30 min(-1) for the negative control (plasmidless strain).


CONCLUSIONS
The thermostable xylanase gene was successfully expressed in both E. coli and L. lactis. The activity of xylanase can be easily detected by the formation of visible clearing zones around the transformed colonies on Remazol Brilliant Blue-Xylan (RBB-Xylan) agar media. However, there were some significant differences in the optimum growth temperature and plasmid stability in the new clones.


CONCLUSIONS
The constructed reporter vector has the potential to be used as a reporter system for Lactococcus as well as E. coli, and it is an addition to the pool of lactococcal vector systems.
Department of Bioprocess Technology, Universiti Putra Malaysia, UPM Serdang, Selangor, Malaysia. raha@biotech.upm.edu.my
A R
AR
Raha
L Y
LY
Chang
A
A
Sipat
K
K
Yusoff
T
T
Haryanti
D001407:Bacillus / Q000201:enzymology / Q000235:genetics*; D043364:Endo-1,4-beta Xylanases / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000378:metabolism; D015870:Gene Expression; D005822:Genetic Vectors; D017045:Lactococcus / Q000378:metabolism*; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000096:biosynthesis
D011994:Recombinant Proteins; D043364:Endo-1,4-beta Xylanases