Abstract: Boholmycin antibiotic is prepared by fermentation of Streptomyces hygroscopicus H617-25 (ATCC No. 53240) in a nutrient medium preferably comprising glycerol, bacto-liver, cornsteep liquor, ammonium sulfate, sodium chloride and calcium carbonate. The antibiotic and pharmaceutically acceptable salts and hydrates thereof and compositions containing these are effective against Gram-positive, Gram-negative and acid-fast bacteria and against bacterial strains which are resistant to previously known aminoglycoside antibiotics and are useful to treat bacterial infections in mammals.

Abstract: Semi-synthetic derivatives of the BU-2867T antibiotics are disclosed. These derivatives are active against experimental mammalian tumors, and may be prepared from enzymatic degradation product(s) of BU-2867T A.

Abstract: Novel peptide antibiotics designated herein as BU-2867T F and G are produced by fermentation of Polyangium brachysporum strain K481-B101 (ATCCC 53080). The new antibiotics are found to have antifungal activity and to inhibit P388 lymphatic leukemia in rodents.

Abstract: Semi-synthetic derivatives of the BU-2867T antibotics are disclosed. These derivatives are active against experimental mammalian tumors, and may be prepared from enzymatic degradation product(s) of BU-2867T A.

Abstract: 3,3'-Neotrehalosadiamine antibiotic is prepared by fermentation of B. pumilus K169-B91 (ATCC No. 53206) in a nutrient medium preferably comprising soybean meal, corn starch, calcium carbonate and magnesium sulfate. The antibiotic and pharmaceutically acceptable salts and hydrates thereof and compositions containing these are useful to treat bacterial infections in mammals.

Abstract: The novel antibiotics boxazomycin A and B, which have the formula: ##STR1## wherein R is --CH.sub.2 OH for boxazomycin A; and R is --CH.sub.3 for boxazomycin B. These new antibiotics, which are produced by cultivating a novel strain of Pseudonocardia (ATCC 53205), inhibit growth of aerobic Gram-positive bacteria and anaerobes with enhanced activity observed in acidic medium.

Abstract: A novel antibiotic complex designated herein as BBM-1675 complex is produced by fermentation of certain novel strains of Actinomadura verrucosospora. The complex may be separated into two major components, BBM-1675 A.sub.1 and A.sub.2, and four minor components, BBM-1675 A.sub.3, A.sub.4, B.sub.1 and B.sub.2, and such components exhibit both antimicrobial activity and antitumor activity.

Abstract: Novel peptides of the formula ##STR1## wherein R is CH.sub.3 --(CH.sub.2).sub.6, CH.sub.3 --(CH.sub.2).sub.4 --CH.dbd.CH--(CH.sub.2).sub.2 and CH.sub.3 (CH.sub.2).sub.8 having antibiotic and antitumor activity are prepared by cultivation of the novel microorganism Polyangium brachysporum. Enzymatic hydrolysis of those peptides gives other peptides useful as intermediates in the preparation of peptides having activity as antibiotics and/or antitumor agents.

Abstract: The novel antibiotics boxazomycin A and B, which have the formula: ##STR1## wherein R is --CH.sub.2 OH for boxazomycin A; and R is --CH.sub.3 for boxazomycin B. These new antibiotics, which are produced by cultivating a novel strain of Pseudonocardia (ATCC 53205), inhibit growth of aerobic Gram-positive bacteria and anaerobes with enhanced activity observed in acidic medium.

Abstract: A new antitumor antibiotic designated herein as BMY-28121 is produced by fermentation of Streptomyces albus strain K731-113 (ATCC 39897). BMY-28121, which may be recovered from the fermentation broth in either its natural free hydroxy form (BMY-28121A) or methyl ether form (BMY-28121B), inhibits gram-positive bacteria and anaerobes and inhibits the growth of mammalian tumors such as P-388 leukemia, L-1210 leukemia and B16 melanoma.

Abstract: A novel antibiotic complex designated herein as BBM-1675 complex is produced by fermentation of certain novel strains of Actinomadura verrucosospora. The complex may be separated into two major components, BBM-1675 A.sub.1 and A.sub.2, and four minor components, BBM-1675 A.sub.3, A.sub.4, B.sub.1 and B.sub.2, and such components exhibit antimicrobial activity and also antitumor activity in certain mouse tumor systems.

Abstract: A novel antibiotic complex designated BBM-2478 is produced by fermentation of an actinomycete strain J907-21 (ATCC 39417). The complex may be separated chromatographically into two bioactive components designated BBM-2478A and BBM-2478B. The BBM-2478A component displays both antibacterial and antitumor activity while the BBM-2478B component has antibacterial activity.

Abstract: A biologically pure culture of Actinomadura Sp. Strain H710-49 (ATCC 39144) is provided. The antibiotic designated BBM-1644 may be produced by fermentation of the subject culture.

Abstract: Disclosed is a process for preparation of the water-soluble peptide antibiotic designated Bu-2517 by fermentation of Empedobacter sp. strain G393-B445 (ATCC 31962).

Abstract: A novel antibiotic complex designated BBM-2478 is produced by fermentation of an actinomycete strain J907-21 (ATCC 39417). The complex may be separated chromatographically into two bioactive components designated BBM-2478A and BBM-2478B. The BBM-2478A component displays both antibacterial and antitumor activity while the BBM-2478B component has antibacterial activity.

Abstract: A novel antitumor antibiotic designated herein as BBM-2040 is produced by fermentation of Streptomyces sp. strain J576-99 (ATCC 39143). BBM-2040, which may be recovered from the fermentation broth in either a desmethanol (BBM-2040B) or methanol-adduct (BBM-2040A) form, inhibits gram positive and acid-fast bacteria and inhibits the growth of tumors such as P388 leukemia in mice.

Abstract: A novel antitumor antibiotic designated herein as BBM-2040 is produced by fermentation of Streptomyces sp. strain J576-99 (ATCC 39143). BBM-2040, which may be recovered from the fermentation broth in either a desmethanol (BBM-2040B) or methanol-adduct (BBM-2040A) form, inhibits gram-positive and acid-fast bacteria and inhibits the growth of tumors such as P388 leukemia in mice.

Abstract: A novel water-soluble peptide designated herein as Bu-2517 is produced by fermentation of Empedobacter sp. strain G393-B445 (ATCC 31962). The antibiotic exists in a cyclic depsipeptide structure and contains the amino acids D-serine, D-proline, L-proline, D-threo-.beta.-hydroxyaspartic acid, L-threo-.beta.-hydroxyaspartic acid, L-arginine and trans-L-3-hydroxyproline and the residue of the C.sub.14 fatty acid, 3-hydroxytetradecanoic acid. The Bu-2517 antibiotic inhibits the growth of a variety of aerobic and anaerobic gram-positive bacteria.

Abstract: A novel peptide antibiotic complex designated herein as Bu-2470 is produced by fermentation of Bacillus circulans strain G493-B6 (ATCC 31,805). Complex Bu-2470 may be separated into four bioactive peptide antibiotics designated as Bu-2470A, B.sub.1, B.sub.2a, and B.sub.2b. The complex and individual bioactive factors possess significant antimicrobial activity.

Abstract: A novel peptide antibiotic complex designated herein as Bu-2470 is produced by fermentation of Bacillus circulans strain G493-B6 (ATCC 31,805). Complex Bu-2470 may be separated into four bioactive peptide antibiotics designated as Bu-2470A, B.sub.1, B.sub.2a, and B.sub.2b. The complex and individual bioactive factors possess significant antimicrobial activity.