Cloning of genes involved in the antifungal activity of a fluorescent Pseudomonas sp

Abstract

The molecular basis of antifungal toxin production by a fluorescent Pseudomonas strain EM 85 was studied. The bacterial strain showed in vitro inhibition of growth of Rhizoctonia solani. NTG mutagenesis of the wild type strain helped in the isolation of a antifungal-toxin-defective mutant AN 21. A genomic library of the wild type strain was constructed in the cosmid vector pLAFR 1 and maintained in an E. coli background. Complementation analysis with cosmid library resulted in the isolation of a cosmid clone which complemented the defective character in the mutant AN 21. The size of the complementing DNA fragment was found to be 23.5kb