Abstract: New glycopeptide antibiotic A82846, comprising A82846A, A82846B and A82846C, is produced by Nocardia orientalis strains NRRL 18098, NRRL 18099 and NRRL 18100. The A82846 antibiotics have activity against Gram-positive bacteria comparable to that of vancomycin.

Abstract: New polyether antibiotic A82810, its acyl and alkyl ester, acyl ester and urethane derivatives, and salts thereof, are useful antibacterial and anticoccidial agents and increase feed-utilization efficiency in animals. Methods of making A82810 by culture of Actinomodura fibrosa sp. nov. NRRL 18348 and synergistic compositions of the A82810 compounds with nicarbazin, 4,4'-dinitrocarbanilide, certain napthalenamine and benzenamine compounds and metichlorpindol are also provided.

Abstract: New glycopeptide antibiotic A83850, comprising A83850A, and A83850B, is produced by Amycolatopsis albus strain NRRL 18532. A83850A and A83850B can be reduced to give new biologically active denatures. The A83850 antibiotics have activity against Gram-positive bacteria comparable to that of vancomycin.

Abstract: New polyether antibiotic A82810, its acyl and alkyl ester, acyl ester and urethane derivatives, and salts thereof, are useful antibacterial and anticoccidial agents and increase feed-utilization efficiency in animals. Methods of making A82810 by culture of Actinomodura fibrosa sp. nov. NRRL 18348 and synergistic compositions of the A82810 compounds with nicarbazin, 4,4'-dinitrocarbanilide, certain napthalenamine and benzenamine compounds and metichlorpindol are also provided.

Abstract: New glycopeptide antibiotic A82846, comprising A82846A, A82846B and A82846C, is produced by Nocardia orientalis strains NRRL 18098, NRRL 18099 and NRRL 18100. The A82846 antibiotics have activity against Gram-positive bacteria comparable to that of vancomycin.

Abstract: New polyether antibiotic A80789, its acyl ester, alkyl ester, and alkyl ether derivatives, and salts thereof, are useful as antibacterial and anticoccidial agents and increase feed-utilization efficiency in animals. Methods of making A80789 by culture of Streptomyces hygroscopicus NRRL 18513, and combinations of the A80789 compounds with nicarbazin, 4,4'-dinitrocarbanilide, certain napthalenamine and benzenamine compounds and are also provided.

Abstract: New glycopeptide antibiotic A80407, comprising A80407A and A80407B, is produced by Kibdelosporangium philippinensis strains NRRL 18198, and NRRL 18199 or A80407-producing mutants of these strains. The A80407 antibiotics have excellent activity against Gram-positive bacteria, increase feed-utilization efficiency in monogastric and ruminant animals and improve weight gains in animals.

Abstract: New glycopeptide antibiotic A83850, comprising A83850A, and A83850B, is produced by Amycolatopsis albus strain NRRL 18532. A83850A and A83850B can be reduced to give new biologically active derivatives. The A83850 antibiotics have activity against Gram-positive bacteria comparable to that of vancomycin.

Abstract: New Polyether antibiotic A82810, its acyl and alkyl ester, acyl ester and urethane derivatives, and salts thereof, are useful antibacterial and anticoccidial agents and increase feed-utilization efficiency in animals. Methods of making A82810 by culture of Actinomodura fibrosa sp. nov. NRRL 18348 and synergistic compositions of the A82810 compounds with nicarbazin, 4,4'-dinitrocarbanilide, certain napthalenamine and benzenamine compounds and metichlorpindol are also provided.

Abstract: New polyether antibiotic A80789, its acyl ester, alkyl ester, and alkyl ether derivatives, and salts thereof, are useful as antibacterial and anticoccidial agents and increase feed-utilization efficiency in animals. Methods of making A80789 by culture of Streptomyces hygroscopicus NRRL 18513, and combinations of the A80789 compounds with nicarbazin, 4,4'-dinitrocarbanilide, certain napthalenamine and benzenamine compounds and are also provided.

Abstract: New glycopeptide antibiotic A80407, comprising A80407A and A80407B, is produced by Kibdelosporangium philippinensis strains NRRL 18198, and NRRL 18199 or A80407-producing mutants of these strains. The A80407 antibiotics have excellent activity against Gram-positive bacteria, increase feed-utilization efficiency in monogastric and ruminant animals and improve weight gains in animals.

Abstract: New antibiotic A80509, its C.sub.1 -C.sub.7 -alkyl ester derivatives and salts are useful antibacterial and anticoccidial agents and improve feed efficiency and growth in animals. Methods of making A80509 by fermentation of, and a biologically pure culture of, Streptomyces mutabilis NRRL 18269 are also provided.

Abstract: New polyether antibiotic A80577, its acyl ester and alkyl ether derivatives, and salts thereof, are useful antibacterial agents and increase feed-utilization efficiency in animals. Methods of making A80577 by culture of Actinomadura verrucosospora, NRRL 18236, and compositions containing an A80577 compound also are provided.

Abstract: Antibiotic A42125, which is produced by a new strain of Nocardia aerocolonigenes, NRRL 18049, is a useful inhibitor of Gram-positive and methane-generating microorganisms. A42125 also increases feed utilization efficiency in ruminants. A biologically purified culture of N. aerocolonigenes NRRL 18049 and a method for producing A42125 by fermentation of this culture are provided.

Abstract: A new strain of Streptomyces pactum, NRRL 15970, and an improved fermentation process for producing the polyether antibiotic A80438 using this microorganism are provided.

Abstract: New polyether antibiotic A80438, its acyl and alkyl ester, alkyl ether and urethane derivatives, and salts thereof, are useful antibacterial and anticoccidial agents and increase feed-utilization efficiency in animals. Method of making A80438 by culture of Streptomyces bobili NRRL 15971 and synergistic compositions comprising (1) and A80438 compound and (2) nicarbazin, 4,4'-dinitrocarbanilide, certain napthalenamine and benzenamine compounds or metichlorpindol are also provided.

Abstract: Antibiotic A42125, which is produced by a new strain of Nocardia aerocolonigenes, NRRL 18049, is a useful inhibitor of Gram-positive and methane-generating microorganisms. A42125 also increases feed utilization efficiency in ruminants. A biologically purified culture of N. aerocolonigenes NRRL 18049 and a method for producing A42125 by fermentation of this culture are provided.

Abstract: New polyether antibiotic A80190, its acyl and alkyl ester, acyl ester and urethane derivatives, and salts thereof, are useful antibacterial and anticoccidial agents and increase feed-utilization efficiency in animals. Methods of making A80190 by culture of Actinomadura oligospora NRRL 15877 and synergistic compositions of the A80190 compounds with nicarbazin, 4,4'-dinitrocarbanilide, certain napthalenamine and benzenamine compounds and metichlorpindol are also provided.

Abstract: Antibiotic A47934 is produced by submerged, aerobic fermentation of new Streptomyces toyocaensis NRRL 15009. The antibiotic is active against gram-positive bacteria in vitro and in vivo. It promotes growth in poultry and swine and serves to enhance feed efficiency in ruminant animals having a developed rumen.

Abstract: Antibiotic A-21978C complexes, in particular the A-21978C complex, comprising microbiologically active, related factors, C.sub.0, C.sub.1, C.sub.2, C.sub.3, C.sub.4, and C.sub.5. A-21978 complex and A-21978C complex are produced by submerged aerobic fermentation of Streptomyces roseosporus NRRL 11379. The individual A-21978C factors are separated and isolated by chromatography. The A-21978 and A-21978C complexes, the A-21978C factors, and pharmaceutically acceptable salts thereof are antibacterial agents and improve growth promotion in poultry.