Discovery of novel metabolites from marine actinomycetes

Department of Microbiology and Anti-infective Discovery, Nereus Pharmaceuticals, Inc., 10480 Wateridge Circle, San Diego, CA 92121, USA.
Current Opinion in Microbiology (Impact Factor: 7.22). 07/2006; 9(3):245-51. DOI: 10.1016/j.mib.2006.03.004
Source: PubMed

ABSTRACT Recent findings from culture-dependent and culture-independent methods have demonstrated that indigenous marine actinomycetes exist in the oceans and are widely distributed in different marine ecosystems. There is tremendous diversity and novelty among the marine actinomycetes present in marine environments. Progress has been made to isolate novel actinomycetes from samples collected at different marine environments and habitats. These marine actinomycetes produce different types of new secondary metabolites. Many of these metabolites possess biological activities and have the potential to be developed as therapeutic agents. Marine actinomycetes are a prolific but underexploited source for the discovery of novel secondary metabolites.

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    ABSTRACT: Since the marine environmental conditions are extremely different from the other ones, marine actinomycetes might produce novel bioactive compounds. Therefore, actinomycete strains were screened from marine water and sediment samples collected from the coastal areas of Northern Vietnam. Ninety-nine actinomycete strains were obtained on starch-casein agar media by dilution technique, only seven strains, named HP112, HP12, HP411, HPN11, HP 11, HPT13 and HPX12, showed significant antibacterial activity against both gram-positive and gram-negative bacteria (Bacillus subtilis ATCC 6633, Staphylococcus epidemidis ATCC 12228, Escherichia coli ATCC 11105). Further studies were carried out with the most active HP411 strain against Candida albicans ATCC 10231. This strain could grow rapidly on starch casein agar and other media with high salt containing 7-10% NaCl at 28-30 o C. Spore-chain of HP411 showed an elongated and circular shape with 10 to 30 spores/chain. Identification of the strain was carried out by employing the taxonomical studies including the 16S rRNA sequence. Based on phylogenetic and phenotypic evidence it is proposed that HP411 to be belongs to species Streptomyces variabilis. The potent of the crude extract of fermentation broth of HP411 that are effective against wide range of pathogens: both gram-positive, gram-negative and fungi. Further studies revealed that the crude extract HP411 could obtain the anticancer activity for cancer cell lines: Hep-G2 (liver cancer cell line); RD (cardiac and skeletal muscle letters cell line); FL (membrane of the uterus cancer cell line). However, the actinomycetes from marine ecosystem will be useful for the discovery of new drugs in the future.
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    ABSTRACT: Streptomyces sp. TP-A0873, isolated from deep-sea water, produces three different classes of secondary metabolites: antimycin, bohemamine, and alkylated butenolides. In order to assess the biosynthetic potential of this strain, draft genome sequencing was carried out. The genome contained at least 14 gene clusters for polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS). Copyright © 2015 Komaki et al.
    Genome Announcements 02/2015; 3(1):e00008-15. DOI:10.1128/genomeA.00008-15
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    ABSTRACT: The occurrence of Actinomycetes, their molecular characteristics, and their release of synthesized odor compounds into soil and the water systems were investigated. The average numbers of Actinomycetes was 9.0 × 105 CFU/g in the soil and 4.8 CFU/mL in the water. The average numbers of Actinomycetes in the soil was highest at the Yangpyeong (YP) testing site (2.2 × 106 CFU/g), followed by the Gyeongan (GA), Paldang (PD), and Cheongpyeong (CP) sites. The Streptomyces genus, which can produce odor compounds such as geosmin and 2-Methylisoborneol (MIB), was dominant (67.6%). An enhanced proportion of Streptomyces with plant soil was also observed by independent pyrosequencing results of cultures. The bacterial diversity of GA and CP was greater than those of YP and PD, and pyrosequencing detected diverse genera of Actinobacteria. The rain leaching model experiment suggested that geosmin and 2-MIB produced by the Actinomycetes could be released into the water systems by rainfall. The concentrations of the geosmin and 2-MIB leached from the planted soils were 2.6 times and 2.8 times greater than those from the unplanted soil. Moreover, the concentration of Streptomyces positively correlated with the amount of geosmin and 2-MIB (R2 = 0.809 and 0.847, respectively).
    Journal of Pure and Applied Microbiology 11/2014; 8(Spl. Edn. 2):103-113. · 0.07 Impact Factor


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