Bioremediation process optimization and effective reclamation of mixed carbamate-contaminated soil by newly isolated Acremonium sp.

Abstract

Global pollution from excessive pesticide use has become a serious environmental and public health problem. The aim of the study was to optimize the fungal mediated simultaneous removal of carbofuran and carbaryl from soil. Carb-PV5 strain was isolated from contaminated soil following enrichment culture technique; based on 18S rRNA sequencing, strain was identified as Acremonium sp. (MK514615); Field Emission Scanning Electron Microscopic analysis reflected its morphology. Towards the development of bioaugmentation strategy for the bioremediation of carbamate-contaminated soil, the process parameters were optimized employing Central Composite Rotatable Method. The experimental studies were performed in the range of biomass (0.2–0.6 g kg−1), temperature (23–33 °C), pH (6–9) and moisture (10–30%). The degradation rate parameters, k and t1/2 were determined to as 0.475, 0.325 d−1 and 5.39, 2.1 d with the corresponding r2 of 0.9491, 0.9964 for zero and first order, respectively. The cube root growth kinetic constant k of Acremonium sp. varied from 0.0469 to 0.0512 (g1/3 L−1/3 h−1) and 0.0378 to 0.0415 (g1/3 L−1/3 h−1) for carbofuran and carbaryl, respectively. To confirm the model appropriacy and sustainability of the optimization procedure, bioremediation experiments were conducted onto real carbamate-contaminated soils. UPLC and GCMS analysis confirmed the successful removal of carbamates. The current study presents the first report on the bioaugmentation studies carried out on the mixed carbamate contaminated soil using newly isolated Acremonium sp.