Characterization of Antifungal Metabolites from Antagonistic Fluorescent Pseudomonads

Abstract

Many Pseudomonas species produce antimicrobial metabolites for pathogen suppression and stimulate the plant growth. So twenty fluorescent pseudomonas strains showed highest antagonism efficiency to soilborne phytopathogens which used throughout the present investigation. These bacteria included five strains P. putida, 3/ P. plecoglossicida, 3/ P. palleroniana, 2/ P. corrugate, 2/ P. entomophila and one from each of P. moraviensis, P. parafulva, P. mosselii, P. anguilliseptica, P. argentinensis. Detection of the genes that encode for the production of antibiotics by these strains such as phenazine-1-carboxylic acid (PCA), phenazine-1-carboxamide (PCN), pyrrolnitrin (PRN), and pyoluteorin (PLT) was done by polymerase chain reaction (PCR) using gene-specific primers. Results clearly showed that eight Pseudomonas strains produced (PCA), twelve strains produced (PCN), nine strains produced (PLT) and two strains produced (PRN). Polymerase chain reaction (PCR) confirmed the obtained result by using TLC. P. putida (SAW19) gave the highest antagonistic potential against tested phytopathogenic fungi and formulated using different carriers to test for its viability on different carriers. The populations of P. putida were markedly higher in vermiculite compared with the carriers under six months incubation period.