A Desert-Adapted Pseudomonas Strain for Pyrene Biodegradation in Rajasthan

Abstract

This investigation explains the isolation and characterization of a Pseudomonas strain that can break down the high-molecular-weight polycyclic aromatic hydrocarbon (PAH) pyrene from petroleumcontaminated soil in Rajasthan's Thar desert. The isolate achieved approximately 40% degradation of pyrene by day 7 and 55% by day 15, using pyrene as the sole carbon source. Development was confirmed through OD₆₀₀ measurements and biomass dry weight analysis. Molecular identification using 16S rRNA sequencing classified the isolate within the Pseudomonas genus. Key findings include the identification of four major intermediate metabolites: 1-hydroxypyrene, pyrene-4,5-dione, cis-4,5-pyrenedihydrodiol and phenanthrene-4,5-dicarboxylic acid, detected using HPLC and GC-MS analyses. These metabolites indicate that degradation proceeds via an oxidative ring-cleavage pathway. The results demonstrate the metabolic capabilities of desert adapted Pseudomonas for application in PAH bioremediation in arid and extreme environments.