In order to search for new antibiotics from anaerobic bacteria, a large number of samples from domestic soil were collected and processed by apropriate methods. A potential strain, Streptococcus sp. An-21-1, was found to produce antimicrobial compounds.
The Results were as follows ;
1. During fermentation, the bacteria grew rapidly up to 20hr, thereafter entered the death phase. The optimal temperature and pH for the bacterial growth were 37℃ and pH 7.0, respectively.
2. Antibiotics were purified from culture broth by solvent extraction, silica gel column chromatography and Sepadex L,H 20 column.
3. Physicochemical properties of Ap-1 and Ap-2 were similar ; Their melting points were between 234-237℃ . Color reactions of ninhydrin, 2,7-dichlorofluorescein, 4-dimethylaminobenzaldehyde, Dragendroffs reagent and 20% H₂S0₄, were positive. Therefore, we assumed that these antibiotics have armine group, immine group, alkaloid, and lipid components. These were stable to heat. UV spectrophotometry showed two peaks at 210㎚ and 260㎚.
From above results, we assumed these antibiotics are belong to the peptide antibiotic family.
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