Bioremediation of Pesticide Contaminated Water using Indigenous Hydrocarbon-Degrading, Biosurfactant-Producing Organisms

Abstract

The pervasive contamination of water by recalcitrant pesticides poses a significant threat to ecosystems and public health, necessitating the development of sustainable remediation technologies. This study investigated the bioremediation of pesticide contaminated water using indigenous hydrocarbon-degrading, biosurfactant-producing microorganisms. Water and sediment samples were collected, and a diverse microbial consortium was isolated and screened. The most prevalent organisms identified were *Pseudomonas aeruginosa* (28.5%), *Bacillus subtilis* (22.0%), and the fungus *Trichoderma harzianum* (15.5%). These isolates were remarkable biosurfactant producers, with *Pseudomonas aeruginosa* exhibiting the highest emulsification index (E24) of 68%. In a 14-day bioremediation assay, both *Trichoderma harzianum* and *Pseudomonas aeruginosa* demonstrated high efficacy in degrading a complex mixture of 13 pesticides. *Trichoderma harzianum* achieved a superior average degradation of 60.12%, showing exceptional efficiency against Cyanazine (82.14%) and Tecnazene (77.78%). *Pseudomonas aeruginosa* achieved an average degradation of 51.56%, with notable performance against Hexachlorobenzene (66.04%). The results confirm that indigenous microbes pre-adapted to hydrocarbon contamination possess innate, broad-spectrum pesticide-degrading capabilities. The concurrent production of biosurfactants was identified as a critical mechanism for enhancing the bioavailability and subsequent degradation of hydrophobic pesticide compounds. The study concludes that bioaugmentation with a tailored consortium of indigenous, biosurfactant-producing bacteria and fungi presents a highly effective, eco-friendly, and promising strategy for the bioremediation of pesticide-polluted water sources.