Studies on the Turfgrass Snow Mold Caused by Typhula ishikariensis III. Suppression of hyphal growth of Typhula ishikariensis by phenazine-1-carboxylic acid produced by Pseudomonas fluorescens

Abstract

A previously-reported bacterium which suppresses hyphal growth of snow mold pathogen Typhula ishihariensis was identified as Pseudomonas fluorescens. Since the culture filtrate of this bacterium suppressed hyphal growth of the same fungus, an attempt to identify the antagonistic component (s) was made in this study. The component (s) was extracted from the culture filtrate of the bacterium and purified by several chromatographies. Various spectrum analysis (IR, UV, Mass, ¹H-NMR and ¹³C-NMR) revealed that the component was phenazine-l-carboxylic acid. A further sod-cup test proved a similar antagonistic effect of this substance on hyphal growth of T. ishihariensis as that of the above culture filtrate, suggesting that this substance might be a key product of the bacterium to suppress growth of the fungus.