MOLECULAR CLONING OF PHYTASE GENE FROM ASUIA279 AND ITS EXPRESSION IN PICHIA PASTORIS SYSTEM

Phytases catalyze the hydrolysis of phytate (myo-inositol hexakisphosphate), one of the major storage form of phosphate in plants, with subsequent release of myo-inositol, phosphate and phytate-bound minerals. Nonruminant animals such as chicken, swine and fish can’t use the organic phosphorus and minerals from their diet because there is no phytase activity in their digestive tract. Phytate degrading enzyme is added to the animal feed diet to improve phosphorus availability from the dietary phytate and at the same time this lessen the phosphate pollution level in areas of intensive animal production as the phosphate would not be excreted out to the environment. ASUIA279, a bacterial strain isolated from Malaysian soil has potentially shown good phytase activity. In the present work, the gene encoding for phytase has been amplified from the plasmid DNA of recombinant ASUIA279(5) obtained from a previous study (unpublished data) by a polymerase chain reaction (PCR) methodology. The amplified phytase gene was extracted, purified then cloned into the pPICZαA plasmid and transformed into Pichia pastorisX-33 strain for enzyme production.