Combined strategies for improving expression of Citrobacter amalonaticus phytase in Pichia pastoris

摘要

Background Phytase is used as an animal feed additive that degrades phytic acid and reduces feeding costs and pollution caused by fecal excretion of phosphorus. Some phytases have been expressed in Pichia pastoris , among which the phytase from Citrobacter amalonaticus CGMCC 1696 had high specific activity (3548?U/mg). Improvement of the phytase expression level will contribute to facilitate its industrial applications.