BIOSURFACTANT AS A PESTICIDE CLEANING AGENT IN LEAFY VEGETABLES PRODUCED BY PSEUDOMONAS FLUORESCENS ISOLATED FROM MANGROVE ECOSYSTEM

Abstract

In this present investigation, biosurfactant was produced by Pseudomonas fluorescens MFS03 isolated from mangrove forest soil using groundnut oil cake as substrate. Characterization of the biosurfactant revealed that, it is a glycolipid with chemical composition of carbohydrate (0.868 mg/ml) and lipid (1.912 mg/ml). Based on the TLC analysis, carbohydrate and lipid with an Rf value of 0.72 were separated and it was partially identified as rhamnolipid. In FT-IR spectral analysis, important absorption bands at 3466.24, 2926.45, 1743.47, 1407.30 and 1162.26 cm-1 indicates the chemical structure is identical to those of rhamnolipids. Biosurfactant was used for the cleanup of insecticide residues in the spinach varieties Amaranthus tricolor. L generally called as Arakkeerai or Killukeerai. The experiment was carried out under in-vitro conditions. Among the different washing solution (Salt, vinegar KMnO4 and biosurfactant) used for the reduction of pesticide residues, biosurfactant solution shows higher reduction. However the amount of biosurfactant and the contact times shows significant role in reducing cypermethrin residues in spinach. Cypermethrin solution with 100ppm concentration was reduced to below 2 ppm, which is safe level using 25 ppm of biosurfactant solution for 5 minutes. The increase in amount of biosurfactant concentration shows decrease in contact time in reducing cypermethrin residues. From this study we concluded that production of biosurfactant using groundnut oil cake is economically low-cost medium and eco-friendly and it can be used as an effective agent to clean up pesticide residues in vegetables and leafy vegetables.