• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.321-326
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• 1996

In the course of screening for new bioactive compounds from oligotrophs in soil, a microorganism, designated as SA-246 and now identified as Micromonospora sp., has been shown to produce a strong antibacterial compound. The active compound was purified from broth filtrate by ethylacetate extraction, silica gel column chromatography, preparative TLC and HPLC, and was identified as crisamicin A based on mass and NMR spectral data. The compound SA- 246 exhibited not only strong antibacterial activity against Gram-positive bacteria but also cytotoxicity against cancer cell lines such as A549 (lung), SK-OV-3 (ovarian), SK-MEL-2 (melanoma), XF498 (central nervous system) and HCT15 (colon).

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.81-85
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• 2002

Oligotrophic bacteria isolated from forest soil showed a specific community consisting of various taxonomic groups compared with those in other soil or aquatic habitats. Based on the cell shape, the isolates were divided into four groups: regular rod, curved/spiral rod, irregular rod, and prosthecate bacteria. The cellular fatty acids 60 oligotrophic isolates were analyzed. At the dendrogram based on cellular fatty acid composition, four clusters(I-IV) were separated at a euclidian distance of about 50. Based on the 16S rDNA sequence analysis, the two representative strains(MH256 and MA828) of cluster 3 showed the close relation to genera, Xathomonas/Stenotrophomonas, but were not included in these genera. The isolates with Q-10 were also studied. They are corresponded to the two large groups in Proteobacteria alpha subdivision. One was incorporated in the genus Bradyrhizobium cluster, which also includes Agromonas, a genus for oligotrophic bacteria. The strains of the other group showed high similarity to the genus Agrobacterium. We attempted to screening of bioactive compounds from oligotrophs which was isolated from forest soil. The active compounds were analyzed by mass and NMR spectrum, one of them identified as crisamicin A. Another one designated as SAPH is a new compound. The results indicate that there were possibilities for finding new compounds from the rare microorganisms such as oligotrophs.