Glycerol, ethylene glycol and propanediol elicit pimaricin biosynthesis in the PI-factor-defective strain Streptomyces natalensis npi287 and increase polyene production in several wild-type actinomycetes

Abstract

Production of pimaricin by Streptomyces natalensis ATCC 27448 is elicited by the PI-factor, an autoinducer secreted by the producer strain during the rapid growth phase. Exogenous PI-factor restored pimaricin production in a mutant strain npi287 defective in PI-factor biosynthesis. During purification of the PI-factor, a second pimaricin-inducing fraction different from PI-factor was isolated from the culture broth of wild-type S. natalensis ATCC 27448. After purification by HPLC and analysis by MS and NMR, this active fraction was shown to contain glycerol and lactic acid. Pure glycerol restored pimaricin production in liquid cultures of the autoinducer-defective npi287 mutant. A similar effect was exerted by ethylene glycol, 1,2-propanediol and 1,3-propanediol but not by higher polyalcohols or by glycerol acetate or glycerol lactate esters. Glycerol stimulated (30-270 %) the production of six different polyene macrolide antibiotics by their respective producer strains. Addition of glycerol to the inducer-defective npi287 strain restored pimaricin production but did not result in extracellular or intracellular accumulation of PI-factor. Exogenously added PI-factor was internalized by the cells in the presence of glycerol, and a mixture of both PIfactor and glycerol produced a slightly higher inducing effect on pimaricin production than PI-factor alone. In summary, glycerol, ethylene glycol and propanediol exert a bypass of the PI-factor inducing effect on pimaricin biosynthesis.

PimM, a PAS domain positive regulator of pimaricin biosynthesis in Streptomyces natalensis

“…Spectrophotometric determination of pimaricin was performed as described elsewhere . HPLC analysis of this antifungal was carried out as described by Recio et al (2006). The fungicidal activity of pimaricin was tested by bioassay using C. utilis CECT 1061 as test organism.…”

Improvement of Natamycin Production by Engineering of Phosphopantetheinyl Transferases in Streptomyces chattanoogensis L10

“…factors related to NTM biosynthesis have been well studied to improve NTM production, including the pathway-specific regulators (14)(15)(16), the gamma-butyrolactone regulatory system (17,18), the pimaricin inducer (PI) factor system (19,20), the P450 epoxidase (21), the phosphate regulation system (22), the pleiotropic regulatory system (23), and the exporter (24). We have previously cloned the scn PKS NTM biosynthetic gene cluster in S. chattanoogensis L10 (14,23).…”

Solid-State Fermentation of Agricultural Residues for the Production of Antibiotics

“…Autoinducers are one of the best-known regulators of secondary metabolism in bacteria (Recio et al 2006 ) and fungi ). There are different types of autoregulatory molecules having ability to trigger wide ranges of antibiotic production (Recio et al 2006 ).…”

“…There are different types of autoregulatory molecules having ability to trigger wide ranges of antibiotic production (Recio et al 2006 ). The regulatory factors of antibiotic biosynthesis are of great interest.…”