Chromatographic Detection of Antibacterial Antibiotics from Pseudomonas fluorescens (TNAU PF1) and Their Effect on Bacterial Wilt Pathogen Ralstonia solanacearum (KK2)

Abstract

Bacterial wilt of tomato is a devastating disease incited by Ralstonia solanacearum (KK2) causing heavy yield loss in India. The antagonist Pseudomonas fluorescens (TNAU PF1) was characterized for antibacterial ability against the bacterial wilt pathogen. Thin-layer chromatography (TLC) identified six distinct antibiotics in crude metabolite of TNAU PF1 strain. The crude antibiotics and the antibiotics 2,4-diacetylphloroglucinol and Phenazine of TNAU PF1 showed best in vitro antibacterial activity against the bacterial wilt pathogen R. solanacearum. The ability of crude antibiotics in inhibiting Ralstonia colonies was higher than the individual antibiotics (2,4-diacetylphloroglucinol and Phenazine) under in vitro. Further, GC-MS analysis of the semi-purified crude extract of Pseudomonas fluorescens (TNAU PF1) identified six antibacterial compounds viz., Phloroglucinol dimethyl ether, Patulin, Hemipyocyanin, Phthalic acid, butyl 2-pentyl ester, Phenazine and 1-Phenazinecarboxylic acid that would be synergistically inhibited the colony multiplication of the pathogen. The study emphasized the antagonistic activity of the Pseudomonas fluorescens (TNAU PF1) for the management of bacterial wilt disease.