@article{MAKHILLIJMMAS2005128480, title = {Phytase Gene Expression in Pichia pastoris and Analyses of its Biochemical Characteristics}, journal = {International Journal of Molecular Medicine and Advance Sciences}, volume = {1}, number = {2}, pages = {116-120}, year = {2005}, issn = {1813-176x}, doi = {ijmmas.2005.116.120}, url = {https://makhillpublications.co/view-article.php?issn=1813-176x&doi=ijmmas.2005.116.120}, author = {Q.Q.Yin,Q. H. Zheng and}, keywords = {Phytase,gene expression,Pichia pastoris,biochemical characteristics}, abstract = {Phytase gene from A. niger was amplified by PCR and inserted into two plasmids (pPICZ? A and pGAPZ? A) to form two shuffle vector cassettes (Vppi and Vpga). P. pastoris were transformed by electroporation Phytase gene was expressed successfully in the host. After 4 d incubation in liquid media, phyatse activity in the supernatant reached the peak, 39.00 F/mL for P. pastoris with Vppi and 28.46 F/mL for P. pastoris with Vpga. They were increased by 51 folds for Vppi phytase and 37 folds for Vpga phytase, compared with the original A. niger (0.76 F/mL ). The analyses of biochemical characteristics of phytases showed that the optimum temperature and pH range were 30-50?C and 2.0-5.5, respectively. The optimum phytase concentrations for the inorganic phosphorous (P) released from soybean were 0.25 F/g soybean for Vppi phytase, 0.50-1.00 F/g for Vpga phytase and wild-type phytase. The expressed phytase from Vppi was better for thermostability and for P released at 0.25, 0.50 and 1.00 F/g soybean levels than Vpga phytase and wild-type phytase.} }