title: Citrobacter amalonaticus phytase on the cell surface of Pichia pastoris exhibits high pH stability as a promising potential feed supplement.
abstract: Phytase expressed and anchored on the cell surface of Pichia pastoris avoids the expensive and time-consuming steps of protein purification and separation. Furthermore, yeast cells with anchored phytase can be used as a whole-cell biocatalyst. In this study, the phytase gene of Citrobacter amalonaticus was fused with the Pichia pastoris glycosylphosphatidylinositol (GPI)-anchored glycoprotein homologue GCW61. Phytase exposed on the cell surface exhibits a high activity of 6413.5 U/g, with an optimal temperature of 60°C. In contrast to secreted phytase, which has an optimal pH of 5.0, phytase presented on the cell surface is characterized by an optimal pH of 3.0. Moreover, our data demonstrate that phytase anchored on the cell surface exhibits higher pH stability than its secreted counterpart. Interestingly, our in vitro digestion experiments demonstrate that phytase attached to the cell surface is a more efficient enzyme than secreted phytase.
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, P. R. China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Li
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, P. R. China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, P. R. China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, P. R. China.
authors.forename: Shuli
authors.initials: S
authors.lastname: Liang
mesh_terms: D010832:6-Phytase / Q000235:genetics* / Q000378:metabolism; D000821:Animal Feed; D002954:Citrobacter / Q000235:genetics*; D004795:Enzyme Stability; D005434:Flow Cytometry; D006863:Hydrogen-Ion Concentration; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D030781:Organisms, Genetically Modified / Q000378:metabolism; D010843:Pichia / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013696:Temperature; D014170:Transformation, Genetic
chemical_list: D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D010832:6-Phytase