Production of Isoprenoids

Abstract

The invention provides a biological method of producing isoprenoids.

1 . A method for production of an isoprenoid compound, comprising:
 (a) culturing a microorganism in a fermentation medium, wherein the microorganism comprises:
 i) a genetic modification to decrease the activity of squalene synthase in the microorganism relative to a wild type microorganism 
 ii) a genetic modification to increase the action of an enzyme that converts hydroxymethylglutaryl-CoA to mevalonic acid together with a genetic modification to increase the action of at least one enzyme selected from the group consisting of
 an enzyme that converts mevalonic acid to phosphomevalonic acid; 
 an enzyme that converts phosphomevalonic acid to phosphomevalonate; and, 
 an enzyme that converts phosphomevalonate to isopentenyl pyrophosphate; 
 
   (b) collecting the isoprenoid compound whose production has been increased from the fermentation medium.   
     
     
         2 . The method of  claim 1 , wherein the microorganism further comprises a genetic modification to increase the action of an enzyme that converts isopentenyl pyrophosphate to dimethylallyl pyrophosphate. 
     
     
         3 . The method of  claim 1 , wherein the isoprenoid product is a sterol, ubiquinone, heme, dolichol or a carotenoid. 
     
     
         4 . The method of  claim 1 , wherein the microorganism comprises a squalene synthase gene under the control of an inducible or repressible promoter. 
     
     
         5 . The method of  claim 4 , wherein the squalene synthase gene is under the control of an inducible promoter and the microorganism is cultured under conditions wherein the inducer for the promoter becomes depleted from the medium. 
     
     
         6 . The method of  claim 1 , wherein the fermentation medium comprises a squalene synthase inhibitor. 
     
     
         7 . The method of  claim 1 , wherein the microorganism is an erg9 mutant. 
     
     
         8 . The method of  claim 1 , wherein the action of HMG-CoA reductase is increased by overexpression of HMG-CoA reductase or the catalytic domain thereof in the microorganism. 
     
     
         9 . The method of  claim 1 , wherein the action of HMG-CoA reductase is increased by increasing gene copy number. 
     
     
         10 . The method of  claim 1 , wherein the microorganism is further genetically modified to increase the action of acetoacetyl Co-A thiolose, and HMG-CoA synthase. 
     
     
         11 . The method of  claim 1 , wherein the microorganism has been genetically modified to increase the action of farnesyl pyrophosphate synthase. 
     
     
         12 . The method of  claim 1 , wherein the microorganism has been genetically modified to overexpress farnesyl pyrophosphate synthase. 
     
     
         13 . The method of  claim 1 , wherein the microorganism is a fungi. 
     
     
         14 . The method of  claim 13 , wherein the fungi is a yeast. 
     
     
         15 . A microorganism which comprises a genetic modification to increase the action of HMGCoA reductase together with a genetic modification to increase the action of mevalonate kinase, phosphomevalonate kinase and diphosphomevalonate decarboxylase.