title: Heterologous expression of the biosynthetic gene clusters of coumermycin A(1), clorobiocin and caprazamycins in genetically modified Streptomyces coelicolor strains.
abstract: The biosynthetic gene clusters of the aminocoumarin antibiotics clorobiocin and coumermycin A(1) and of the liponucleoside antibiotic caprazamycin were stably integrated into the genomes of different host strains derived from Streptomyces coelicolor A3(2). For the heterologous expression of clorobiocin derivatives in a chemically defined medium, inclusion of 0.6% of the siloxylated ethylene oxide/propylene oxide copolymer Q2-5247 into the growth medium proved to result in a 4.8-fold increase of productivity. Presumably, this copolymer acts as an oxygen carrier. The additional inclusion of cobalt chloride (0.2-2 mg l(-1)) dramatically increased the percentage of the desired compound clorobiocin within the total produced clorobiocin derivatives. This is very likely due to a stimulation of a cobalamin-dependent methylation reaction catalyzed by the enzyme CloN6 of clorobiocin biosynthesis. All three investigated host strains (S. coelicolor M512, M1146 and M1154) gave similar production rates of total clorobiocin derivatives (on average, 158 mg l(-1) in the presence of 0.6% Q2-5247 and 0.2 mg l(-1) CoCl(2)). In contrast, heterologous production of caprazamycin derivatives was optimal in strain M1154 (amounts of 152 mg l(-1) on average).
authors.affiliation: Pharmaceutical Biology, Pharmaceutical Institute, Eberhard Karls-Universität Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Flinspach
authors.forename: Lucia
authors.initials: L
authors.lastname: Westrich
authors.forename: Leonard
authors.initials: L
authors.lastname: Kaysser
authors.forename: Stefanie
authors.initials: S
authors.lastname: Siebenberg
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Gomez-Escribano
authors.forename: Mervyn
authors.initials: M
authors.lastname: Bibb
authors.forename: Bertolt
authors.initials: B
authors.lastname: Gust
authors.forename: Lutz
authors.initials: L
authors.lastname: Heide
mesh_terms: D049933:Aminocoumarins / Q000378:metabolism; D001381:Azepines / Q000378:metabolism*; D015870:Gene Expression; D005798:Genes, Bacterial; D005810:Multigene Family; D009675:Novobiocin / Q000031:analogs & derivatives* / Q000096:biosynthesis; D048372:Streptomyces coelicolor / Q000235:genetics / Q000378:metabolism*
chemical_list: D049933:Aminocoumarins; D001381:Azepines; D009675:Novobiocin; C006260:clorobiocin; C004628:coumermycin