High-activity phytase compositions containing a carbohydrate polymer

摘要

A process for preparing an aqueous liquid comprising phytase comprises: a) culturing in an aqueous medium a microorganism of the genus Aspergillus or Trichoderma having a heterologous phytase gene under the control of a glucoamylase (for Aspergillus) or cellobiohydrolase (for Trichoderma) promoter under conditions that allow recombinant expression of the phytase where the medium comprises as a feed for the microorganism an assimilable carbon source and an assimilable nitrogen source; b) filtering the aqueous medium to remove the microorganisms to give an aqueous filtrate and c) subjecting the filtrate from b) to ultrafiltration to give an aqueous liquid having a phytase concentration of at least 14,000 FTU/g. A phytase containing granulate having a phytase activity of at least 6000 FTU/g is useful as an ingredient in a animal feed. An animal feed composition contains a phytase containing granulate having a phytase activity of at least 6000 FTU/g and at least 15% (w/w) of an edible carbohydrate.