NEW PHYTASE AND PRODUCTION OF PHYTASE

摘要

PROBLEM TO BE SOLVED: To obtain a new phytase differing in enzymatic characteristics from well-known ones derived from yeast through converting phytin to an assimilative form by yeast. SOLUTION: This new phytase is an extracellular phytase produced by Arxula adeninivorans, having the following physicochemical properties: optimally reactive temperature: >=75 deg.C; optimum pH for phytase activity at the optimally reactive temperature: 4.5-5.0; and optimum pH for phytase activity at 60 deg.C: 4.5-5.0. It is preferable that the above new phytase is produced by aerobically culturing such a kind of yeast as to belong to the genus Arxula such as Arxula adeninivorans (e.g. Arxula adeninivorans CBS7370) to effect accumulating and collecting the aimed phytase. By the way, it is preferable that microorganisms capable of producing the aimed phytase is screened by inoculating microorganisms such as yeast capable of producing the aimed phytase into a medium with phytin as a sole phosphate source doubling as carbon source and then selecting microorganisms viable in the medium.