Microbial production of epoxides

Abstract

A method for microbial production of epoxides and other oxygenated products is disclosed. The method uses a biocatalyst of methanotrophic bacteria cultured in a biphasic medium containing a major amount of a non-aqueous polar solvent. Regeneration of reducing equivalents is carried out by using endogenous hydrogenase activity together with supplied hydrogen gas. This method is especially effective with gaseous substrates and cofactors that result in liquid products.

We claim:  
     
         1 . A method for regenerating reducing equivalents in a bioreactor configured for utilizing reducing equivalents in a methane-monooxygenase-catalyzed reaction for oxidizing a substrate into an oxygenated product comprising: 
 culturing a reconstituted lyophilized whole cell enzyme preparation of methanotrophic bacteria containing methane monooxygenase and hydrogenase in the bioreactor, said bioreactor comprising a liquid phase comprising a major amount of a non-polar non-aqueous solvent and a minor amount of a polar aqueous medium;    continuously dissolving an effective amount of hydrogen gas in said non-polar non-aqueous solvent, such that said hydrogen gas and NAD + are converted by the hydrogenase into NADH, thereby regenerating reducing equivalents.    
     
     
         2 . The method of  claim 1  wherein said oxygenated product is propylene oxide and said substrate is propylene.  
     
     
         3 . The method of  claim 1  wherein said methanotrophic bacteria are selected from the group consisting of Methylosinus, Methyloccus, and Methylomonas, and mixtures thereof.  
     
     
         4 . The method of  claim 3  wherein said methanotrophic bacteria are  Methylosinus trichosporium  OB3b.