ABSTRACT
A novel series of microbial metabolites were discovered in fermentation broths of two soil isolates. Both cultures were identified as strains of Micromonospora chalcea. Production of the metabolites, named macquarimicins, was monitored by an HPLC assay. A seven-day fermentation yielded 27 mg/liter of macquarimicin A. With MICs of 50 to 100 micrograms/ml, macquarimicin A has only very low activity against strains of Bacteroides and other anaerobes. Macquarimicin B has inhibitory activity against the leukemia cell line P-388.
Subject(s)
Anti-Bacterial Agents/isolation & purification , Antibiotics, Antineoplastic/isolation & purification , Macrolides , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/therapeutic use , Antibiotics, Antineoplastic/therapeutic use , Chromatography, High Pressure Liquid , Fermentation , Leukemia P388/drug therapy , Microbial Sensitivity Tests , Micromonospora , Tumor Cells, Cultured/drug effectsABSTRACT
A novel antibiotic complex, named the calbistrins, has been discovered in the culture broth of a soil fungus. The producing organism, designated AB 1875C-28, was identified as a strain of Penicillium restrictum. Calbistrin A, the most potent of the 4-membered complex, has MICs of 0.78 micrograms/ml against Candida albicans. Only poor activity is observed against non-candida yeasts, filamentous fungi and bacteria.
Subject(s)
Antifungal Agents/biosynthesis , Antifungal Agents/pharmacology , Penicillium/chemistry , Polyenes/chemical synthesis , Polyenes/pharmacology , Animals , Aspergillus/drug effects , Candida/drug effects , Fermentation , Lethal Dose 50 , Mice , Microbial Sensitivity Tests , Microbiological Techniques , Penicillium/classification , Saccharomyces cerevisiae/drug effectsABSTRACT
Tirandalydigin is a new tetramic acid antibiotic which was discovered in a screen designed to find compounds with activity against pathogenic anaerobic bacteria. It was named tirandalydigin because it possesses structural features that are common to both tirandamycin and streptolydigin. The producing culture, strain AB 1006A-9, is a Streptomyces and was compared to the streptomycetes that synthesize tirandamycin and streptolydigin. It is closely related to the former culture and was named Streptomyces tirandis subsp. umidus. Tirandalydigin has MICs in the range of 0.5 to 32 micrograms/ml against many pathogenic anaerobes, streptococci, enterococci and legionellae.
Subject(s)
Aminoglycosides , Anti-Bacterial Agents/isolation & purification , Streptomyces/classification , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Chromatography, High Pressure Liquid , Fermentation , In Vitro Techniques , Microbial Sensitivity Tests , Microscopy, Electron, ScanningABSTRACT
The altromycins are novel anthraquinone-derived antibiotics related to the pluramycins. They are produced by an actinomycete, AB 1246E-26, which was isolated from a South African bushveld soil. The altromycins have Gram-positive antibacterial activity with MICs of 0.2 to 3.12 micrograms/ml against Streptococci and Staphylococci.
Subject(s)
Actinomycetales/metabolism , Aminoglycosides , Anti-Bacterial Agents/biosynthesis , Bacteria/drug effects , Soil Microbiology , Actinomycetales/classification , Anti-Bacterial Agents/pharmacology , Fermentation , Staphylococcus/drug effects , Streptococcus/drug effectsABSTRACT
The pacidamycins are a new complex of nucleosidyl-peptide antibiotics with highly specific activity against Pseudomonas aeruginosa. They are produced by Streptomyces coeruleorubidus AB 1183F-64 which was isolated from a soil sample collected at Offenburg in the FRG. The mature spore masses of the producing organism are greenish gray to blue, and the spore chains are arranged in spirals. After the structures of the pacidamycins were determined, the fermentation medium was supplemented with component amino acids. This resulted in the directed biosynthesis of several members of the complex. The overall antibiotic recovered was increased from 1 approximately 2 mg/liter to more than 100 mg/liter through a combination of strain selection, medium manipulation and amino acid feeding experiments.
Subject(s)
Anti-Bacterial Agents , Anti-Bacterial Agents/biosynthesis , Oligopeptides/biosynthesis , Peptides , Pseudomonas aeruginosa/drug effects , Soil Microbiology , Streptomyces/metabolism , Anti-Bacterial Agents/pharmacology , Culture Media , Fermentation , Intercellular Signaling Peptides and Proteins , Oligopeptides/pharmacology , Pyrimidine Nucleosides/biosynthesis , Pyrimidine Nucleosides/pharmacology , Streptomyces/classification , Streptomyces/growth & developmentABSTRACT
Nocardia lurida has been shown to produce two novel quinone antibiotics, benzanthrins A and B. The antibiotics were discovered in concentrated butanol extracts of fermentation broths and were separated by TLC and HPLC. Benzanthrins A and B were produced in a fermentation medium consisting of glucose, yeast, selected peptones and CaCO3. The antibiotics were present primarily at 66 hours in shake flask fermentations and from 66 to 162 hours in 14-liter fermentors. Benzanthrins A and B inhibited a number of Gram-positive pathogenic bacteria but were inactive against Gram-negative bacteria.