Nematicidal activity of microbial pigment from Serratia marcescens.

Ineffectiveness of available nematicides and the high damage caused by plant-parasitic nematodes result in the urgent need to find some natural remedy for their control. Bioactivity of the pigment extracted from Serratia marcescens was screened for controlling nematodes at their juvenile stage. Test pigment was found effective against juvenile stages of Radopholus similis and Meloidogyne javanica at low concentrations (LC50 values, 83 and 79 μg/mL, respectively) as compared with positive control of copper sulphate (LC50 values, 380 and 280 μg/mL, respectively). The pigment also exhibited inhibition on nematode egg-hatching ability. Characterisation of extracted pigment with TLC, FTIR, HPLC, HPTLC and spectroscopic analysis confirmed the presence of prodigiosin as a bioactive metabolite. Considering the sensory mechanism of pathogen recognition by nematodes, the use of microbial secondary metabolites can be effective for nematode control rather than using whole organism.