Marine actinomycetes as a source of novel secondary metabolites

Abstract

A set of 600 actinomycetes strains which were isolated from marine sediments from various sites in the Pacific and Atlantic Oceans were screened for the production of bioactive secondary metabolites. Marine streptomycete strains were found to be producers of well known chemically diverse antibiotics isolated from terrestrial streptomycetes, as in the case of marine Micromonospora strains. New marine members of the rare genus Verrucosispora seem to be a promising source for novel bioactive secondary metabolites as shown in the case of the abyssomicin producing strain AB-18-032.

Proximicin A, B and C, Novel Aminofuran Antibiotic and Anticancer Compounds Isolated from Marine Strains of the Actinomycete Verrucosispora†

“…HPLC-diode array monitoring of extracts from freshly isolated microorganisms is, as we have shown before [11], a powerful technique in the identification of novel secondary metabolites and in this study resulted in the detection of proximicins in two Verrucosispora strains isolated from very different marine locations. It is astonishing that strain AB-18-032, which was isolated from sediment collected in the Pacific Ocean, produced in addition to the PKS type 1-derived abyssomicins the same metabolite, proximicin A, as strain MG-37 which was isolated from a sediment from the Atlantic Ocean.…”

Streptomyces iranensis sp. nov., isolated from soil

“…Although molecular systematic data show that the genus is clearly over-speciated (Lanoot et al, 2004), other polyphasic studies based on a combination of genotypic and phenotypic features continue to identify novel species and indicate that the genus Streptomyces as a whole is underspeciated (Kim & Goodfellow, 2002). Members of novel Streptomyces species are in demand as a source of new, commercially significant, bioactive compounds (Berdy, 1995;Fiedler et al, 2005).The Microbial Biotechnology Laboratory of the University of Tehran has been interested in isolating actinomycetes from Iranian soils, with the purpose of selecting strains with potential for biotechnological application.The aim of the present study was to classify a Streptomyceslike strain, designated HM 35 T , based on a polyphasic analysis. To determine its taxonomic position, morphological, physiological, chemotaxonomic and molecular genetic data were analysed.…”

Caboxamycin, a new antibiotic of the benzoxazole family produced by the deep-sea strain Streptomyces sp. NTK 937

“…It is becoming increasingly clear that actinomycetes isolated from marine habitats are a rich source of new natural products, including drug candidates. [1][2][3][4][5] Extracts from the culture filtrate of strain NTK 937 showed a prominent peak in the HPLC-diode array analysis that had an unusual UV-visible spectrum, albeit it was similar to that of nataxazole from our HPLC-UV-Vis database which contains 867 entries, mostly antibiotics. 6 Nataxazole, a new member of the benzoxazole family of antibiotics, was extracted from terrestrial Streptomyces sp.…”