The effect of space flight on the production of actinomycin D by Streptomyces plicatus

The effect of space flight on production of the antibiotic actinomycin D by Streptomyces plicatus WC56452 was examined onboard the US Space Shuttle mission STS-80. Paired space flight and ground control samples were similarly prepared using identical hardware, media, and inoculum. The cultures were grown in defined and complex media under dark, anaerobic, thermally controlled (20 degrees C) conditions with samples fixed after 7 and 12 days in orbit, and viable residuals maintained through landing at 17 days, 15 h. Postflight analyses indicated that space flight had reduced the colony-forming unit (CFU) per milliliter count of S. plicatus and increased the specific productivity (pg CFU(-1)) of actinomycin D. The antibiotic compound itself was not affected, but its production time course was altered in space. Viable flight samples also maintained their sporulation ability when plated on agar medium postflight, while the residual ground controls did not sporulate.

The effect of carbon source, temperature and aeration on the production of ascosteroside, a novel antifungal agent, by Ascotricha amphitricha

This paper describes the optimization of production of ascosteroside, a novel antifungal agent with an alpha-linked glycoside of a lanosterone-type triterpenoid structure. Glucose, sorbose and inositol were determined to be the best carbon sources for the production of ascosteroside. Temperature affected levels of ascosteroside, with production being highest at 16 degrees C with 1% glucose, and lowest at 32 degrees C. Dissolved oxygen levels were found to be critical in the production of ascosteroside in fermenter cultures. In order for production of ascosteroside to occur in fermenter cultures, the threshold level of dissolved oxygen was found to be above 26%.

Pyrrolosporin A, a new antitumor antibiotic from Micromonospora sp. C39217-R109-7. I. Taxonomy of producing organism, fermentation and biological activity

Strain C39217-R109-7 (ATCC 53791) is an actinomycete strain isolated from a soil sample collected at Puerto Viejo, Peru. It produces a new antitumor antibiotic, designated pyrrolosporin A. Taxonomic studies on its morphological, cultural and physiological characteristics identified this producing strain as Micromonospora sp. C39217-R109-7. Pyrrolosporin A shows antimicrobial activity against Gram-positive bacteria and it is weakly active against Gram-negative bacteria. Pyrrolosporin A prolongs the life span of mice inoculated with P388 leukemia cells.

Ascosteroside, a new antifungal agent from Ascotricha amphitricha. I. Taxonomy, fermentation and biological activities

Ascosteroside, a novel antifungal compound, was isolated from the culture broth of Ascotricha amphitricha. This compound is an alpha-linked glycoside of a lanostane type triterpenoid. It is active against yeasts such as Candida albicans and Saccharomyces cerevisiae and against filamentous fungi but shows no activity against bacteria. It is not toxic to mammalian cells at concentrations up to 150 microM. In a mouse model, the compound afforded protection comparable to that of ketoconazole.

Korkormicins, novel depsipeptide antitumor antibiotics from Micromonospora sp C39500: fermentation, precursor directed biosynthesis and biological activities

Micromonospora sp C39500, isolated in our laboratory from a soil sample, produced a complex of seven novel depsipeptide antitumor antibiotics, designated korkormicins. The major component of the complex, korkormicin A, has a MW of 1452 and a molecular formula of C66H84N16O22. Korkormicin A exhibits potent in vivo antitumor activity against P388 leukemia and M109 lung carcinoma implanted intraperitoneally (ip) in mice, with effective doses of 0.05-0.20 mg kg-1 injection-1, for five or three ip injections, respectively. It is also active against Gram-positive bacteria but inactive against Gram-negative bacteria. The production of korkormicin A was enhanced by 3-fold when 0.1% L-valine was added to the production culture at 48 h. A titer of 401.0 micrograms ml-1 was achieved in the fermenter culture supplemented with 0.1% L-valine.

Large scale production and semi-purification of kedarcidin in a 1000-L fermentor

Actinomycete strain ATCC 53650 was grown in a 1000-L fermentor containing 680 L of medium and the production of kedarcidin was monitored by HPLC. The titers of kedarcidin in the fermentor cultures were 0.49-0.53 mg ml-1. A quick and efficient purification method involving the use of anion exchange resin DE23 (batch adsorption-desorption) and an ultrafiltration system yielded high recovery (65% yield) of kedarcidin from the fermentor culture. Over 200 grams of lyophilized kedarcidin of 70% purity was recovered from each of two 1000-L fermentor cultures using this process.

Eupenifeldin, a novel cytotoxic bistropolone from Eupenicillium brefeldianum

Eupenifeldin was isolated from cultures of Eupenicillium brefeldianum ATCC 74184 by extraction and crystallization. The compound was identified as a pentacyclic bistropolone on the basis of spectral data and its complete structure was established by single-crystal X-ray analysis. The compound is cytotoxic against the HCT-116 cell line and has in vivo antitumor activity in the P388 leukemia model.

The effect of cerulenin on the production of esperamicin A1 by Actinomadura verrucosospora

Addition of cerulenin (0.25-1.0 mM) to cultures of Acinomadura verrucosospora before the onset of esperamicin synthesis inhibited the production of esperamicin A1 by the microorganism. This result indicates that esperamicin A1 is biosynthesized in part by the polyketide pathway. Addition of cerulenin to the cultures during the active production phase led to a net decrease in esperamicin A1 production. The 14C-acetate labeling pattern of esperamicin A1 in the cultures with or without addition of cerulenin at the active production phase also demonstrated the instability of esperamicin A1 in the fermentation. This suggests that esperamicin A1 is unstable and degradation occurs during the active production phase. Addition of the neutral resin Diaion HP-20 (1%) to the fermentation enhanced the production of esperamicin A1 by 53%.

Improved processes for the production and isolation of dynemicin A and large-scale fermentation in a 10000-liter fermentor

Supplementing the culture of Micromonospora chersina sp. nov. No. M956-1 with NaI (0.5 mg/l) enhanced the production of dynemicin A by 35-fold in shake flask culture. Homogeneous dynemicin A was obtained from the whole broth extract by Dicalite chromatography, Sephadex LH-20 chromatography and vacuum liquid chromatography. Gram quantities of dynemicin A were obtained from the fermentation of M. chersina sp. nov. No. M956-1 in a 10,000-liter fermentor.

Kedarcidin, a new chromoprotein antitumor antibiotic. I. Taxonomy of producing organism, fermentation and biological activity

Strain L585-6 (ATCC 53650) is an actinomycete isolated from a soil sample collected in Maharastra State, India. It produces a new chromoprotein antitumor antibiotic, designated kedarcidin. Taxonomic studies demonstrated that strain L585-6 is an unidentified and unknown actinomycete. Kedarcidin shows potent antitumor activity against implanted P388 leukemia (3.3 micrograms/ml/kg) and B16 melanoma (2 micrograms/kg) in mice. Kedarcidin also shows potent antimicrobial activity against Gram-positive bacteria but no activity against Gram-negative bacteria.

A selective medium for enumeration and recovery of Pseudomonas cepacia biotypes from soil

TB-T medium provides a high degree of selectivity for and detection of Pseudomonas cepacia biotypes upon initial plating from soil. TB-T medium consists of a basal medium with glucose as the sole carbon source and asparagine as the sole nitrogen source. The selectivity of TB-T medium is based on the combination of trypan blue (TB) and tetracycline (T) (pH 5.5). On TB-T medium, 216 of 300 isolates (72%) from five different soil types were identified as P. cepacia. The remaining 28% were facultative organisms that could be separated readily from P. cepacia by anaerobic glucose fermentation and by their inability to grow at 41 degrees C. Molds were controlled on low soil dilutions by adding crystal violet, nystatin, or both. Elimination of either ingredient or elevation of the pH to 7.5 resulted in a pronounced loss of selectivity. The efficiency of recovery varied considerably among P. cepacia strains but was high enough for some strains (76 to 86%) to permit quantitative studies. TB-T medium combines a defined formulation with high selectivity and allows recovery of P. cepacia biotypes from low soil dilutions (10(1) to 10(3)).