Precursor-directed biosynthesis of 6-deoxyerythronolide B analogs in Streptomyces coelicolor: understanding precursor effects.
A fermentation process employing precursor-directed biosynthesis is being developed for the manufacture of 6-deoxyerythronolide B (6-dEB) analogues. Through a plasmid-based system in Streptomyces coelicolor, 6-dEB synthesis is catalyzed by 6-dEB synthase (DEBS). 6-dEB synthesis is abolished by inactivation of the ketosynthase (KS) 1 domain of DEBS but can be restored by providing synthetic activated diketides. Because of its inherent catalytic flexibility, the KS1-deficient DEBS is capable of utilizing unnatural diketides to form various 13-substituted 6-dEBs. Here we characterize process variables associated with diketide feeding in shake-flask experiments. 13-R-6-dEB production was found to depend strongly on diketide feed concentrations, on the growth phase of cultures at feeding time, and on the R-group present in the diketide moiety. In all cases a major portion of the fed diketides was degraded by the cells.
Department of Process Science, Kosan Biosciences, Inc., 3832 Bay Center Place, Hayward, California 94545, USA.
T
T
Leaf
L
L
Cadapan
C
C
Carreras
R
R
Regentin
S
S
Ou
E
E
Woo
G
G
Ashley
P
P
Licari
D003470:Culture Media; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000096:biosynthesis*; D006868:Hydrolysis; D013302:Streptomyces / Q000378:metabolism*
D003470:Culture Media; C034277:6-deoxyerythronolide B; D004917:Erythromycin