Rare actinobacteria: a potential source of bioactive polyketides and peptides.

Polyketides and peptides obtained from actinobacteria are important therapeutic compounds which include front line antibiotics and anticancer drugs. Many screening programs are directed towards isolation of bioactive compounds from these organisms but the chances of finding novel antimicrobial leads among common actinobacteria are fast dwindling. As a result, the focus has shifted to the members of less exploited genera of rare actinobacteria.

Culturable rare actinomycetes from Indian forest soils: Molecular and physicochemical screening for biosynthetic genes.

Background And Objectives: Rare actinomycetes are a promising source of novel metabolites of pharmaceutical importance. The current study focussed on selective isolation of specific genera of rare actinomycetes and screening the isolates for biosynthetic genes particularly polyketide synthases (PKS) and non ribosomal peptide synthetases (NRPS).

Materials And Methods: The soil samples were subjected to various pre-treatments like 1.

Novel aromatic polyketides from soil Streptomyces spp.: purification, characterization and bioactivity studies.

Aromatic polyketides are important therapeutic compounds which include front line antibiotics and anticancer drugs. Since most of the aromatic polyketides are known to be produced by soil dwelling Streptomyces, 54 Streptomyces strains were isolated from the soil samples. Five isolates, R1, B1, R3, R5 and Y8 were found to be potent aromatic polyketide producers and were identified by 16S rRNA gene sequencing as Streptomyces spectabilis, Streptomyces olivaceus, Streptomyces purpurascens, Streptomyces coeruleorubidus and Streptomyces lavendofoliae respectively.

Rhodomycin analogues from Streptomyces purpurascens: isolation, characterization and biological activities.

During a screening program for bioactive natural products, a potential Streptomyces sp was isolated from soil. On the basis of biochemical, cultural, physiological and 16S rRNA gene analysis, it was identified as Streptomyces purpurascens. The isolate was grown in liquid medium and the crude antibiotic complex was obtained by ethyl acetate extraction.