A9145, a New Adenine-Containing Antifungal Antibiotic: Fermentation

Abstract

A9145 is a basic, water-soluble, antifungal antibiotic which is produced in a complex organic medium by Streptomyces griseolus. The metabolite has a molecular weight of 510, and contains adenine as well as sugar hydroxyl and amino groups. Although glucose, fructose, glucose polymers, and some longchain fatty acid methyl esters supported biosynthesis, oils were superior, with cottonseed oil being preferred. Several ions and salts, especially Co2+, P043-, and CaCO3, were stimulatory. Adenine, nucleosides, and some amino acids increased the accumulation of A9145 in shaken-flask fermentors. Enrichment of the culture medium with tyrosine afforded maximal enhancement of antibiotic production in both flask and tank fermentors. Control of the dissolved 02 level was also critical, the optimal concentration being 3 x 10-2 to 4.5 x 10-2 ,mole of 02/ml. Optimization of various fermentation parameters increased antibiotic titers approximately 135-fold in shaken flask fermentors and 225-fold in stirred vessels.A new antifungal antibiotic, A9145, is produced by a strain of Streptomyces griseolus, NRRL-3739, isolated from a soil sample. This basic, water-soluble antibiotic has a molecular weight of 510, contains sugar hydroxyl and amino groups, and yields one mole of adenine upon mild acid hydrolysis (R. L. Hamill and M. M. Hoehn, Abstr. 11th Intersci. Conf. Antimicrob. Ag. Chemother., p. 21, 1971 Staley Manufacturing Co.), 1.5% Nutrisoy flour (Archer-Daniels-Midland Co.), 0.2% Nadrisol (National Distiller's Products Co.), 0.2% blackstrap molasses, 0.1% CaCO3, and 2.5% agar in distilled water (final pH 6.5).Fermentor inoculum. S. griseolus was transferred aseptically, as a lyophilized pellet containing approximately 2 x 106 spores, to 250-ml widemouth Erlenmeyer flasks. These flasks contained 50 ml of a seed medium composed of 1% glucose, 3% Dextrin 700, 1.5% Nutrisoy grits (Archer-DanielsMidland Co.), 0.5% Amber BYF 300 (Amber Laboratories), 0.5% blackstrap molasses, and 0.2% CaCO3, which had been adjusted to pH 6.5 and brought to 1 liter with tap water. Incubation was with agitation on a rotary shaker at 250 rev/min (5-cm stroke) at 30 C. After 30 hr, a second seed stage, 100 ml of the seed medium in a 1-liter flask, was inoculated from the first. After an additional 24-hr incubation period under the same conditions of temperature and agitation, the second seed stage was used to inoculate fermentors with a volume of the mycelial suspension equal to 1% (v/v) of the fermentation medium.Fermentors. In initial investigations, widemouth 250-ml Erlenmeyer flasks containing 50 ml of medium were used, and incubation was as previously described. Larger-volume fermentations for supply of the metabolite were conducted in fully baffled, stirred vessels of conventional design with a total capacity of 40 liters and a 1:1 height-diameter ratio for the 25 liters of medium. Dissolved oxygen content of the broth was monitored by use of a modification of a galvanic membrane electrode previously described (1)

Transcription termination control of the S box system: Direct measurement of S -adenosylmethionine by the leader RNA

“…Sinefungin, an analog of SAM produced by Streptomyces sp. in which methionine is replaced by ornithine (20), acts as a competitive inhibitor of many SAM-dependent methyltransferase reactions (21). Sinefungin failed to promote ykrW transcription termination, but increased read-through in the presence of SAM Ϸ4-fold when added at a 200-fold molar excess (Fig.…”

Differential binding of S -adenosylmethionine S -adenosylhomocysteine and Sinefungin to the adenine-specific DNA methyltransferase M. Taq I 1 1Edited by T. Richmond

“…Methyl groups may be transferred to N, O, S and C-nucleophiles in such diverse molecules as proteins, nucleic acids, lipids and several small molecules (Maw, 1981). The MTases are inhibited by Sinefungin (also known as adenosyl-ornithine), an antibiotic originally isolated from Streptomyces griseolus (Boeck et al, 1973), which strongly competes with binding of AdoMet. Four X-ray crystal structures have been described for AdoMetdependent MTases; one for catechol MTase from rat brain (Vidgren et al, 1994), and three for double-strand-specific DNA MTases.…”

Production, optimization and purification of an antifungal compound from Streptomyces capoamus MTCC 8123

“…Phenylalanine, isoleucine, methionine, and tyrosine are the most suitable amino acids for antifungal metabolite production whereas the addition of arginine, glycine, and valine repressed the synthesis of the antifungal metabolite (Table 2). Aromatic amino acids such as tyrosine and phenyl alanine are reported to enhance the production of adenine-containing antifungal antibiotic from Streptomyces species (Boeck et al, 1973). Arginine 08…”