Molecular Cloning and Production of Recombinant Phytase from Bacillus subtilis ASUIA243 in Pichia pastoris

Phytase gene obtained from Bacillus subtilis ASUIA243 was cloned into a medium vector and transformed into E. coli. Restriction enzyme digestion was conducted to get blunt-ended phytase gene and ligated into the Pichia expression vector, pPICZαA. The recombinant vector, pPICZαA-243HPp was then linearized with PmeI and transformed into P. pastoris strain X33. Screening for multi copy gene number of transformants was done by re-plating the selected colonies on increasing concentration of zeocin. One positive clone, X243HPp#2 was then grown in BMGY media as the starting culture, followed by induction in BMMY media for protein expression study. The supernatant was then analysed by SDS-PAGE and Western blot method to check the protein expression.ABSTRAK: Gen fitase yang didapati daripada Bacillus subtilis ASUIA243 diklonkan sebagai vektor perantara dan berubah menjadi E. coli. Sekatan pencernaan enzim dijalankan untuk mendapatkan gen fitase berhujung tumpul dan diligatkan dengan vektor ekspresi Pichia, pPICZαA. Vektor rekombinan, pPICZαA-243HPp kemudian dilinearkan dengan PmeI dan berubah menjadi P. pastoris strain X33. Penyaringan untuk nombor gen berbilang salinan yang menjalani transformasi genetik dijalankan dengan menyalur semula koloni terpilih dengan penambahan kepekatan zeocin. Satu klon positif, X243HPp#2 kemudian dibiarkan hidup dalam perantara BMGY sebagai kultur permulaan, diikuti dengan aruhan dalam perantara BMMY untuk kajian penglahiran protein. Supernatan kemudian dikaji dengan SDS-PAGE dan kaedah sap Western untuk menyemak penglahiran protein.KEYWORDS:  phytase, Bacillus subtilis, Pichia pastoris, gene cloning.