Abstract: Antibiotic 10381a1, wherein R is hydrogen, is a cytosine-containing antibiotic producible by culturing the novel microorganism Streptomyces arginensis in an aqueous medium and isolation thereof. Derivatives wherein R is a C1 to C3 alkyl ester of antibiotic 10381a1, are also disclosed along with the pharmaceutically acceptable salts of both the native and esterified forms. Antibiotic 10381a1 inhibits the growth of selected species of yeast, fungi and bacteria. This invention also relates to a novel process for the preparation of the antibiotics 10381b and to a method of using antibiotics 10381b to promote growth in meat-producing animals. These antibiotics are also obtained by the fermentation of a nutrient medium with the novel microorganism Streptomyces arginensis and are active against selected species of bacteria.

Abstract: Antibiotic 10381a.sub.1, wherein R is hydrogen, is a cytosine-containing antibiotic producible by culturing the novel microorganism Streptomyces arginensis in an aqueous medium and isolation thereof. Derivatives wherein R is a C.sub.1 to C.sub.3 alkyl ester of antibiotic 10381a.sub.1, are also disclosed along with the pharmaceutically acceptable salts of both the native and esterified forms. Antibiotic 10381a.sub.1 inhibits the growth of selected species of yeast, fungi and bacteria. This invention also relates to a novel process for the preparation of the antibiotics 10381b and to a method of using antibiotics 10381b to promote growth in meat-producing animals. These antibiotics are also obtained by the fermentation of a nutrient medium with the novel microorganism Streptomyces arginensis and are active against selected species of bacteria.

Abstract: Antibiotic 10381a.sub.1, wherein R is hydrogen, is a cytosine-containing antibiotic producible by culturing the novel microorganism Streptomyces arginensis in an aqueous medium and isolation thereof. Derivatives wherein R is a C.sub.1 to C.sub.3 alkyl ester of antibiotic 10381a.sub.1, are also disclosed along with the pharmaceutically acceptable salts of both the native and esterified forms. Antibiotic 10381a.sub.1 inhibits the growth of selected species of yeast, fungi and bacteria. This invention also relates to a novel process for the preparation of the antibiotics 10381b and to a method of using antibiotics 10381b to promote growth in meat-producing animals. These antibiotics are also obtained by the fermentation of a nutrient medium with the novel microorganism Streptomyces arginensis and are active against selected species of bacteria.

Abstract: Antibiotic 10381a.sub.1, wherein R is hydrogen, is a cytosine-containing antibiotic producible by culturing the novel microorganism Streptomyces arginensis in an aqueous medium and isolation thereof. Derivatives wherein R is a C.sub.1 to C.sub.3 alkyl ester of antibiotic 10381a.sub.1, are also disclosed along with the pharmaceutically acceptable salts of both the native and esterified forms. Antibiotic 10381a.sub.1 inhibits the growth of selected species of yeast, fungi and bacteria. This invention also relates to a novel process for the preparation of the antibiotics 10381b and to a method of using antibiotics 10381b to promote growth in meat-producing animals. These antibiotics are also obtained by the fermentation of a nutrient medium with the novel microorganism Streptomyces arginensis and are active against selected species of bacteria.

Abstract: Antibiotic 10381a.sub.1, wherein R is hydrogen, is a cytosine-containing antibiotic producible by culturing the novel microorganism Streptomyces arginensis in an aqueous medium and isolation thereof. Derivatives wherein R is a C.sub.1 to C.sub.3 alkyl ester of antibiotic 10381a.sub.1, are also disclosed along with the pharmaceutically acceptable salts of both the native and esterified forms. Antibiotic 10381a.sub.1 inhibits the growth of selected species of yeast, fungi and bacteria. This invention also relates to a novel process for the preparation of the antibiotics 10381b and to a method of using antibiotics 10381b to promote growth in meat-producing animals. These antibiotics are also obtained by the fermentation of a nutrient medium with the novel microorganism Streptomyces arginensis and are active against selected species of bacteria.

Abstract: Novel antibiotic U-68,204 is produced in a fermentation under controlled conditions using a biologically pure culture of the microorganism Streptomyces thiolactonus, NRRL 15439. This antibiotic is active against various Gram-positive bacteria. Thus, antibiotic U-68,204 can be used in various environments to eradicate or control such bacteria.

Abstract: Novel antibiotic U-68,204 is produced in a fermentation under controlled conditions using a biologically pure culture of the microorganism Streptomyces thiolactonus, NRRL 15439. This antibiotic is active against various Gram-positive bacteria. Thus, antibiotic U-68,204 can be used in various environments to eradicate or control such bacteria.

Abstract: The present invention relates to a fermentation process for producing allylic methyl-hydroxylated novobiocin and derivatives thereof.

Abstract: The present invention relates to a fermentation process for producing allylic methyl-hydroxylated novobiocin and derivatives thereof. These hydroxy novobiocins (II) are useful as antibiotics.

Abstract: The present invention relates to a fermentation process for producing allylic methyl-hydroxylated novobiocin and derivatives thereof.

Abstract: A novel microbiological process for preparing 4-thiouracil, a known and useful compound. The compound is produced by the controlled fermentation of the new microorganism Streptomyces libani subsp. soldani, NRRL 8173, and its strains W and P having the NRRL designations NRRL 8174 and NRRL 8175, respectively.