Effects of methylmalonyl-CoA mutase gene knockouts on erythromycin production in carbohydrate-based and oil-based fermentations of Saccharopolyspora erythraea.
In carbohydrate-based fermentations of Saccharopolyspora erythraea, a polar knockout of the methylmalonyl-CoA mutase (MCM) gene, mutB, improved erythromycin production an average of 126% (within the range of 102-153% for a 0.95 confidence interval). In oil-based fermentations, where erythromycin production by the wild-type strain averages 184% higher (141-236%, 0.95 CI) than in carbohydrate-based fermentations, the same polar knockout in mutB surprisingly reduced erythromycin production by 66% (53-76%, 0.95 CI). A metabolic model is proposed where in carbohydrate-based fermentations MCM acts as a drain on the methylmalonyl-CoA metabolite pool, and in oil-based fermentations, MCM acts in the reverse direction to fill the methylmalonyl-CoA pool. Therefore, the model explains, in part, how the well-known oil-based process improvement for erythromycin production operates at the biochemical level; furthermore, it illustrates how the mutB erythromycin strain improvement mutation operates at the genetic level in carbohydrate-based fermentations.
Reeves
Andrew R
AR
Fermalogic Inc., 2201 West Campbell Park Drive, Chicago, IL 60612, USA.
Brikun
Igor A
IA
Cernota
William H
WH
Leach
Benjamin I
BI
Gonzalez
Melissa C
MC
Weber
J Mark
JM
D001426:Bacterial Proteins / Q000235:genetics*; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000032:analysis; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D004917:Erythromycin / Q000096:biosynthesis*; D005285:Fermentation / Q000235:genetics; D005798:Genes, Bacterial; D005818:Genetic Engineering; D007218:Industrial Microbiology / Q000379:methods*; D008765:Methylmalonyl-CoA Mutase / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D016296:Mutagenesis; D009154:Mutation; D009821:Oils / Q000032:analysis / Q000378:metabolism; D010858:Pigmentation / Q000235:genetics; D016930:Saccharopolyspora / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D013171:Spores, Bacterial / Q000235:genetics
D001426:Bacterial Proteins; D002241:Carbohydrates; D003470:Culture Media; D009821:Oils; D004917:Erythromycin; D008765:Methylmalonyl-CoA Mutase