title: Comparison of extracellular Escherichia coli AppA phytases expressed in Streptomyces lividans and Pichia pastoris.
abstract: A phytase gene (appA) from Escherichia coli was cloned into Streptomyces lividans and expressed as an extracellular protein which was then compared with the same enzyme expressed in Pichia pastoris. The phytase expressed in S. lividans was not glycosylated and had a molecular mass of 45 kDa. Compared with the glycosylated phytase expressed in P. pastoris, this non-glycosylated phytase was 25-50% less active (p < 0.05) at pH 2 to 3.5 or at 45 and 55 degrees C, but 50% more active (p < 0.05) at 75 degrees C. The thermo-tolerance of the non-glycosylated phytase was 26 and 48% higher (p < 0.05) than that of the glycosylated phytase at 45 and 55 degrees C, but was 80 and 94% lower (p < 0.05) at 65 degrees and 75 degrees C, respectively.
authors.affiliation: Department of Animal Science, Cornell University, Ithaca, NY 14853, USA. XL20@cornell.edu
authors.forename: Chad H
authors.initials: CH
authors.lastname: Stahl
authors.forename: David B
authors.initials: DB
authors.lastname: Wilson
authors.forename: Xin Gen
authors.initials: XG
authors.lastname: Lei
mesh_terms: D010832:6-Phytase / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D003001:Cloning, Molecular; D004789:Enzyme Activation; D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005110:Extracellular Space / Q000201:enzymology; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D010843:Pichia / Q000737:chemistry / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D011786:Quality Control; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D013045:Species Specificity; D013302:Streptomyces / Q000737:chemistry / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D013696:Temperature; D014170:Transformation, Genetic
chemical_list: D011994:Recombinant Proteins; D010832:6-Phytase