Carbon catabolite regulation of rebeccamycin production inSaccharothrix aerocolonigenes

Summary A new antitumor antibiotic named rebeccamycin was isolated from fermentations of an actinomycete,Saccharothrix aerocolonigenes. A defined medium was developed to study the regulation of synthesis of rebeccamycin byS. aerocolonigenes. In glucose medium formation of rebeccamycin was detected only after glucose was depleted. Examination of eleven different carbon sources revealed that carbon catabolite regulation is a major control mechanism for rebeccamycin production.     

Identification of indolepyruvic acid as an intermediate of rebeccamycin biosynthesis

Summary Experimental evidence is presented to demonstrate that indolepyruvic acid is an intermediate in the rebeccamycin biosynthetic pathway. [3-¹⁴C]Indolepyruvic acid was prepared and efficiently incorporated (8%) into rebeccamycin bySaccharothrix aerocolonigenes.     

Korkormicins,novel depsipeptide antitumor antibiotics fromMicromonospora 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 potentin 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 48h. A titer of 401.0 g ml^–1 was achieved in the fermenter culture supplemented with 0.1%l-valine.     

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°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. Received 21 August 2001/ Accepted in revised form 30 July 2002     

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

Summary Supplementing the culture ofMicromonospora 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 ofM. chersina sp. nov. No. M956-1 in a 10000-liter fermentor.     

Local expansion of allergen-specific CD30+Th2-type gamma delta T cells in bronchial asthma.

BACKGROUND: T lymphocytes infiltrating airways during the allergic immune response play a fundamental role in recruiting other specialized cells, such as eosinophils, by secreting interleukin 5 (IL-5), and promoting local and systemic IgE synthesis by producing IL-4. Whether these presumed allergen-specific T cells are of mucosal or systemic origin is still a matter of conjecture. MATERIALS AND METHODS: Immunophenotype, IL-4 production, and in vitro proliferative response to specific or unrelated allergens were analyzed in the bronchoalveolar lavage (BAL) fluid lymphocyte suspensions obtained from untreated patients with allergic asthma. Healthy subjects and patients affected by pulmonary sarcoidosis, a granulomatous lung disease characterized by infiltrating Th1 CD4+ lymphocytes, served as controls. RESULTS: The proportions of gamma delta T lymphocytes, mostly CD4+ or CD4- (-)CD8-, was higher in asthmatic subjects than in controls (p < 0.05). Most BAL gamma delta CD4+ lymphocytes of asthmatic patients displayed the T cell receptor (TCR)-gamma delta V delta 1 chain. While CD30 antigen coexpression on the surface of BAL alpha beta(+) T lymphocytes was low (ranging from 5 to 12%), about half of pulmonary gamma delta T cells coexpressed it. These cells produced IL-4 and negligible amounts of interferon-gamma (IFN gamma), and proliferated in vitro in response to purified specific but not unrelated allergens. In contrast, control or sarcoidosis gamma delta T cells never displayed the CD30 surface molecule or produced significant quantities of IL-4. CONCLUSIONS: These findings not only confirm our previous hypothesis that the allergen-specific Th2-type lymphocytes found in the lungs of asthmatic patients are gamma delta T cells belonging to airway mucosal immunocytes, but also strongly support the notion that asthma is a local rather than a systemic disease.     

The effect of cerulenin on the production of esperamicin A1 byActinomadura verrucosospora

Summary Addition of cerulenin (0.25–1.0 mM) to cultures ofActinomadura 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. The¹⁴C-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%.     

The effects of space flight on the production of monorden by Humicola fuscoatra WC5157 in solid-state fermentation

The effect of space flight on the production of the antibiotic monorden on two types of agar media, T8 and PG, by Humicola fuscoatra WC5157 was examined on board the US Space Shuttle mission STS-77 in May 1996. Paired space-flight and ground control samples were prepared using identical hardware, protocol, media, and inoculum. Inoculation occurred simultaneously for both groups 2.5 h after launch. The flight and ground samples were allowed to grow for the entire 10-day mission in a dark, thermally controlled (22 °C) environment. Post-flight HPLC analysis of the flight and ground sample extracts indicated that the production of monorden by H. fuscoatra WC5157 in the flight samples was higher than in the ground samples in both agar media. In the T8 medium, the production of monorden in the flight and ground samples was 11.6 ± 3.5 μg and 8.9 ± 1.1 μg respectively (30% increase). In the PG medium, the production of monorden in the flight and ground samples was 23.8 ± 3.3 μg and 8.2 ± 2.2 μg respectively (190% increase). The production of monorden in the flight and ground control samples was confirmed by HPLC-MS analysis. Received: 30 September 1997 / Received revision: 23 December 1997 / Accepted: 2 January 1998     

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

Summary 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.     

Effect of neutral resins on the production of dynemicins byMicromonospora chersina

Addition of Diaion HP-20 or Amberlite XAD-8 resin to the fermentation ofMicromonospora chersina ATCC 53710 enhanced the production of dynemicin A by 4.7- and 6.9-fold, respectively. Addition of resin suppressed the production of other dynemicin analogs, which comprised 65% of the dynemicin complex in the fermentation.