| Abstrakt: |
In a search for antibiotics active against Mycobacterium tuberculosisvar. hominisseveral hundred antagonists have been encountered and one called Streptomyces sp.EI5in our records was chosen for intensive study because of its marked activity against the mycobacteria and the low animal toxicity of its crude filtrate.1The present report is the account of a study of this organism and the antibiotic it produces.Methods and Results. A. Morphological and Cultural Characteristics of Streptomyces sp.EI5.Since preliminary tests of solubility and antibacterial activity indicated that the antibiotic produced by S.spEI5is similar to streptomycin and streptothricin, a comparison of the organisms that produce these antibiotics was made.Streptomyces sp.EI5was morphologically similar to Streptomyces griseus, and both organisms produced a soluble yellow to yellow-brown pigment when grown at room temperature on nutrient agar, glucose agar, starch agar, and gelatin. Only S. griseusproduced pigment on potato agar. The color of the aerial mycelium varied from white to tea-green with S.griseusand from white to gray with S. sp.EI5. The vegetative mycelium of S. griseuswas white to cream colored and that of S.sp.EI5yellow to tannish orange. Streptomyces sp.EI5was not susceptible to the S. griseusactinophage of Reilly, Harris and Waksman.2These observations indicate that S. griseusand S. sp.EI5, are similar but significantly different organisms.Streptomyces lavendulaeproduced a darker brown pigment on glucose agar, nutrient agar and glucose broth than S. sp.EI5, and in addition produced pigment on the potato plug. Further, slide cultures on Czapek's medium at 30°C showed the aerial mycelium of S. lavendulaeto be pink to lavender, and the hyphae often coiled terminally, in contrast to the white to gray color and the straight hyphae of S. sp.EI5. The conidia of S. sp.EI5were observed to be oval to globose and considerably smaller than those of S. lavendulae.These differences indicate that S. lavendulaeand S. sp.EI5are not identical. |
