Chlorpyrifos Removal in an Artificially Contaminated Soil Using Novel Bacterial Strains and Cyclodextrin. Evaluation of Its Effectiveness by Ecotoxicity Studies

Abstract

The removal of chlorpyrifos (CLP) from the environment is a matter of general interest, because it is one of the most widely used insecticides in the world but presents a high toxicity and persistence in the environment. Biological strategies are considered as a good option to remediate different environmental compartments. Assisted natural attenuation was used to find the ability of different kinds of soils to mineralise CLP. In this way, two soils showed the capacity to degrade CLP (R and LL up to 47.3% and 61.4% after 100 d, respectively). Thus, two CLP-degrading strains, Bacillus megaterium CCLP1 and Bacillus safensis CCLP2 were isolated from them, showing the capacity to degrade up to 99.1 and 98.9% of CLP in a solution with an initial concentration of 10 mg L−1 after 60 d. Different strategies were considered for increasing the effectiveness of soil bioremediation: (i) biostimulation, using a nutrients solution (NS); (ii) bioaugmentation, using B. megaterium CCLP1 or B. safensis CCLP2; (iii) bioavailability enhancement, using randomly methylated β-cyclodextrin (RAMEB), a biodegradable compound. When bioaugmentation and RAMEB were jointly inoculated and applied, the best biodegradation results were achieved (around 70%). At the end of the biodegradation assay, a toxicity test was used to check the final state of the bioremediated soil, observing that when the degrading strains studied were individually inoculated into the soil, the toxicity was reduced to undetectable levels.

Genome analysis for the identification of genes involved in phenanthrene biodegradation pathway in Stenotrophomonas indicatrix CPHE1. Phenanthrene mineralization in soils assisted by integrated approaches

“…These models were selected according to the FOCUS (2006) work group. The Solver tool (included in Microsoft Excel statistical software) and the equations described in Lara-Moreno et al (2022a) were used, depending on the kinetic model that fits the best to each experimental set of data. Kinetics parameters were obtained from kinetic models: k 1 , k 2 , α, β (mineralization rate constants), tb (time at which rate constant changes), and DT 50 (time taken for 50% of substance to disappear by dissipation processes).…”

Current Trends in Bioaugmentation Tools for Bioremediation: A Critical Review of Advances and Knowledge Gaps

“…On the other hand, ammonium chloride and monosodium glutamate served as biostimulants that fostered the growth of indigenous petroleum or hydrocarbon degraders [ 72 ]. The addition of methylated β-cyclodextrin for bioavailability enhancement was previously proposed by [ 25 ] in a study of the degradation of chlorpyrifos from soil. The biostimulation effect of neat biodiesel was recently reviewed by [ 59 ].…”

Selective and Accurate Detection of Nitrate in Aquaculture Water with Surface-Enhanced Raman Scattering (SERS) Using Gold Nanoparticles Decorated with β-Cyclodextrins

“…β-cyclodextrin molecules, owing to their structural characteristics, possess the capability to efficiently encapsulate various target substances within their cavities. This property has rendered them widely employed in the realms of both chemistry and biology [ 48 , 49 , 50 , 51 , 52 , 53 ]. The combination of metal nanoparticles with supramolecular compounds such as cyclodextrins can effectively identify the target substance and has been widely used in molecular recognition and photoelectrochemical sensors [ 42 , 54 , 55 , 56 , 57 ].…”