RESUMO
Phenazine-1-carboxylic, 2-hydroxy-phenazine-carboxylic acid and 2-hydroxy-phenazine active against phytopathogenic fungi were detected in fermentation broth of Pseudomonas chlororaphis subsp.aureofaciens strains UCM B-111 and UCM B-306--components of insectofungicide biopreparation gaupsin using chromato-mass-spectrometric methods; strain B-306 produced antifungal antibiotic pyrrolnitrin together with phenazines. Supernatants of fermentation broth of P chlororaphis subsp. aureofaciens B-111 and B-306 strains grown in King A medium and exopolymers preparations obtained from these supernatants using evaporation, dialysis and liophylisation were highly active against tobacco mosaic virus (TMV). At a dose of 10 mg/ml they reduced TMV infectivity by 76-96%, at concentrations 1 and 0.1 mg/ml the antiviral effect was decreased to 40-62 and 14-27%, respectively. Dialysis did not influence the antiviral activity of isolated preparations. The latter contained 2-7.6 % of carbohydrates including neutral monosaccharides: fucose, mannose, galactose and glucose.