Characterization of Streptomyces MITKK-103, a newly isolated actinomycin X2-producer.

TitleCharacterization of Streptomyces MITKK-103, a newly isolated actinomycin X2-producer.
Publication TypeJournal Article
Year of Publication2006
AuthorsKurosawa, K, Bui, VP, VanEssendelft, JL, Willis, LB, Lessard, PA, Ghiviriga, I, Sambandan, TG, Rha, CK, Sinskey, AJ
JournalAppl Microbiol Biotechnol
Date Published2006 Aug
KeywordsBacterial Typing Techniques, Dactinomycin, DNA, Bacterial, DNA, Ribosomal, HL-60 Cells, Humans, Microscopy, Electron, Scanning, Molecular Sequence Data, Nucleic Acid Hybridization, Phylogeny, Pigments, Biological, RNA, Ribosomal, 16S, Sequence Analysis, DNA, Sequence Homology, Nucleic Acid, Soil Microbiology, Streptomyces

A new actinomycete strain designated MITKK-103 was isolated from the soil of a flowerpot using a humic acid agar medium. The newly isolated strain was able to produce a large amount of actinomycin X2 even under nonoptimized growing conditions and serves as a promising source of this antibiotic. Actinomycin X2 has higher cytotoxicity toward cultured human leukemia (HL-60) cells than does actinomycin D, and it induces cell death via apoptosis. A nearly complete 16S ribosomal DNA (rDNA) sequence from the isolate was determined and found to have high identity (98.5-100%) with Streptomyces galbus, Streptomyces griseofuscus, and Streptomyces padanus, indicating that MITKK-103 belongs to the genus Streptomyces. The isolate clustered with species belonging to the S. padanus clade in a 16S-rDNA-based phylogenetic tree and showed 75% overall homology to S. padanus ATCC 25646 in DNA-DNA relatedness analysis. Although the growth of the isolate was somewhat different from the three species mentioned, the strain MITKK-103 most closely resembles S. padanus on the basis of the morphological and phenotypic characteristics, phylogenetic analysis, and genotypic data. As such, this is the first report of a strain of S. padanus capable of producing actinomycins.

Alternate JournalAppl Microbiol Biotechnol
Citation Key100
PubMed ID16374634