ANTIFUNGAL ACTIVITY OF SECONDARY METABOLITES PRODUCED BY PSEUDOMONAS FLUORESCENS

Abstract

Thirty isolates of Pseudomonas fluorescens obtained from citrus rhizosphere were tested for antifungal activity against Phytophthora spp. P. fluorescens isolate Pf₂₀ was found efficient in inhibiting the mycelial growth upto 38.88%. The antifungal compounds were extracted with equal volume of ethyl acetate and were tentatively identified on thin layer chromatography (TLC) at R_f 0.28. The antifungal compounds extracted from P. fluorescens at 5% were found inhibitory to the growth of Rhizoctonia solani (42.79%), Phytophthora parasitica (28.57%), P. palmivora (25.98%) and Fusarium solani (20.45%). In case of HPTLC analysis the characteristic colour and fluorescent band after derivatization with anisaldehyde reagent proved the presence of secondary metabolites in crude extract.