Patent ID: 7741082

Claim:
A process of preparing a partially purified enzyme concentrate of phenylalanine dehydrogenase (PDH) and/or formate dehydrogenase (FDH), the process comprising: a. preparing a fermentation broth containing a microorganism capable of producing PDH and/or FDH; b. microfluidizing the fermentation broth while maintaining the temperature of said fermentation broth between about 4° C. and 30° C. to form a microfluidized broth containing the PDH and/or FDH; c. clarifying the microfluidized broth by treating the broth with a flocculating agent to coagulate cell debris and to remove DNA and unwanted proteins, thereby forming a clarified broth; d. filtering the clarified broth to give a filtrate; and e. concentrating the filtrate to give said partially purified enzyme concentrate, the concentrate containing: i. said PDH having a PDH activity of about 400 IU/ml to about 1000 IU/ml; and/or ii. said FDH having a FDH activity of about 20 IU/ml to about 200 IU/ml, wherein the enzyme concentrate is capable of reductively aminating a keto-containing compound into a chiral amine-containing compound; wherein said chiral amine-containing compound, without isolation from the enzyme concentrate, is capable of being BOC-protected; and wherein, optionally, the clarifying comprises contacting the microfluidized broth with diatomaceous earth and the filtering comprises filtering the diatomaceous earth with a filter press.