抄録
Several antibiotic substances produced by various kinds of streptomyces are resembling each others. They are adsorbed by activated carbon from the fermented broth and eluted into acid methanol. They are soluble in water and insoluble in Organic solvents. However, they are different in toxicity, antibacterial spectra, and some chemical characters. At first Umezawa et al. (1-4) divided them into two groups, that is, streptomycin and streptothricin-group substances. According to the authors (1), substances of streptothricin-group are in the following characters.
1) They are obtained from the broth of streptomyces.
2) They inhibit widely Gram-positive and Gram-negative bacteria.
3) They are adsorbed by activated carbon, eluted Into acid methanol, soluble in water and insoluble in organic solvents such as acetone, ether, benzene and petroleum ether.
4) The streptomycin-fast E. coli is almost as susceptible to them as the normal culture.
5) The streptothricin-fast E. coli is more resistant to them than the normal culture.
Thereafter Umezawa classified the streptothricin-group substances into two groups, the streptothricin-group A and the streptothricin B. The former, if injected into mice, shows a later appearing toxicity, but not the latter. A strain of B. anthracis in Umezawa's laboratory is more resistant to streptothricin-group A than B. subtilis (N. R. R. L. B558), but is rather more susceptible to streptothricin B. Streptothricin-group A substances are produced by various kinds of streptomyces, but streptothricin B is obtained from the broth of strains belonging to S.fradiae.
In the present paper characters of strains producing streptothricin-group A substances and streptothricin B are described.
