HETEROLOGOUS EXPRESSION OF A CHITINASE GENE FROM AEROMONAS CAVIAEIN PSEUDOMONAS FLUORESCENS

ANTONIUS SUWANTO (Department of Biology, Faculty of Mathematics and Sciences,)
AMARILA MALIK (Southeast Asian Regional Center for Tropical Biology (SEAMEO BIOTROP), Bogor,)
BUDI TJAHJONO (Department of Plant Pests and Diseases, Faculty of Agriculture, Bogor Agricultural University, Bogor-16144, Indonesia: ')
ROB HARLING (Department of Crop Science. Scottish Agricultural College, Edinburgh EH9 3JG, UK.)

BIOTROPIA - The Southeast Asian Journal of Tropical Biology
No. 20 (2003)

A transcriptional fusion for an Aeromonas caviae chitinase gene was constructed under the control of a constitutive promoter of the kanaraycin resistance gene (PKmR). The construct was inserted into a medium copy number broad host range plasmid vector to yield recombinant plasmid pAM340, which harbored transcriptional fusion PKmR- chi. Another transcriptional fusion, Ptac-chi, in a recombinant plasmid pAM630, was conducted as comparison. Triparental mating of E. coli  carrying the recombinant plasmids with Pseudomotws fluorescens  5100, a phyllosphere bacterium, was performed. Pseudomonas fluorescens  5100 exconjugants were examined for constitutive expression of chitinase employing a spectrophotometric assay; they showed stronger chitin degradation activity than Escherichia coli transformants. Using a fungal antagonism plate assay, this chitinolytic P. fluorescens, however, could not inhibit selected phytopathogenic fungi. Keywords:    Aeromonas   caviae/  chitinase   gene/transcriptional   fusion/PKm'V   Vtac-chilPseudomonas fluorescens