Changing Biosynthetic Profiles by Expressing bldA in Streptomyces Strains

Abstract

Recently we described an unusual way of activating a cryptic gene cluster when we explored the origin of the bald phenotype of Streptomyces calvus. Complementation of S. calvus with a correct copy of bldA restored sporulation and additionally promoted production of a new natural products. In this study we report on the expression of bldA in several Streptomyces strains that have been described as "poorly sporulating" strains. In seven out of 15 cases, HPLC profiling revealed the production of new compounds, and in two cases the overproduction of known compounds. Two compounds were isolated and their structures were determined.

The Draft Genome Sequence of Actinokineospora bangkokensis 44EHWT Reveals the Biosynthetic Pathway of the Antifungal Thailandin Compounds with Unusual Butylmalonyl-CoA Extender Units

“…Under laboratory conditions only a few compounds are produced by a strain while their genomes comprise often more than 20 biosynthetic gene clusters. Cryptic clusters have been activated by heterologous expression [ 1 ], changing growth conditions [ 2 ] or by the manipulation of regulatory genes [ 3 , 4 ]. The knowledge of the genome sequence and the biosynthetic cluster composition of a secondary metabolite gives insights into the biosynthetic pathway.…”

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from <em>Streptomyces diastatochromogenes</em> T&#252;6028

“…The application of the OSMAC approach (cultivation of one strain under different conditions) to wake up silent gene clusters may sometimes not be enough. Genetic manipulation of regulatory genes, such as the pleiotropic regulator genes adpA 44 and bldA 45,46 , is also an effective method to activate the production of other secondary metabolites.…”

Insight into Saccharothrix espanaensis Grown in Different Media:Transcriptome and Natural Product Analysis

“…300 to 400 bps fragments, which are located before the genes BN6_78320 , BN6_01860 and BN6_68440 and supposed to include the promoters of these genes, were PCR-amplified with the corresponding primers (Table 1) introducing 5´ XbaI and 3´ KpnI sites and cloned into XbaI-and KpnI-digested pGUS plasmid to create the above mentioned expression vectors. The resulting vectors, as well as the empty vector pGUS, were conjugated into S. espanaensis as previously described [18]. The apramycin-and spectinomycinresistant exconjugands were grown in TSB medium at 28°C and prepared for Gus assay.…”

“…The resulting fragments were cloned into XbaI-and BamHI-digested pKC1132 plasmid to create the above mentioned disruption vectors. The constructed vectors were introduced into S. espanaensis by intergeneric conjugation using E. coli ET12567/pUZ8002 as previously described [18]. The single crossover mutants were grown in apramycincontaining TSB medium at 28°C.…”