Biodegradation of Dichlorodiphenyltrichloroethanes (DDTs) and Hexachlorocyclohexanes (HCHs) with Plant and Nutrients and Their Effects on the Microbial Ecological Kinetics

Abstract

Four pilot-scale test mesocosms were conducted for the remediation of organochlorine pesticides (OCPs)-contaminated aged soil. The results indicate that the effects on degradation of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were in the following order: nutrients/plant bioaugmentation (81.18 % for HCHs; 85.4 % for DDTs) > nutrients bioaugmentation > plant bioaugmentation > only adding water > control, and nutrients/plant bioaugmentation greatly enhanced the degradation of HCHs (81.18 %) and DDTs (85.4 %). The bacterial community structure, diversity and composition were assessed by 454-pyrosequencing of 16S recombinant RNA (rRNA), whereas the abundance of linA gene was determined by quantitative polymerase chain reaction. Distinct differences in bacterial community composition, structure, and diversity were a function of remediation procedure. Predictability of HCH/DDT degradation in soils was also investigated. A positive correlation between linA gene abundance and the removal ratio of HCHs was indicated by correlation analyses. A similar relationship was also confirmed between the degradation of HCHs/DDTs and the abundance of some assemblages (Gammaproteobacteria and Flavobacteria). Our results offer microbial ecological insight into the degradation of HCHs and DDTs in aged contaminated soil, which is helpful for the intensification of bioremediation through modifying plant-microbe patterns, and cessation of costly and time-consuming assays.

Monitoring of DDT in Agricultural Soils under Organic Farming in Poland and the Risk of Crop Contamination

“…Humic acids can increase the apparent solubility of DDT (Carter and Suffet 1982 ), but amending the soil with high quantities of organic matter was found to significantly retard DDT biodegradation, possibly due to binding of DDT to dissolved organic carbon (Kantachote et al 2004 ). Further research on the complex interactions between soil physical–chemical properties, its microbiome, including the microbial functional degradation potential, and the crops’ physiological contribution to the soil environment in relation to the possibilities to degrade DDT is thus needed to understand the behaviour of DDT residues (Sun et al 2015 ), particularly under climate change conditions (Gaur et al 2018 ). However, even though seasonal variation in DDT concentrations has been reported in soils (Zhang et al 2013 ), in agreement with the finding of differential release of residues into atmosphere (Motelay-Massei et al 2005 ; Liu et al 2009 ), sampling consistently at the end of summer during our monitoring exercise should have also reduced the risk of a bias in the results due to seasonal variability.…”

The impact on the soil microbial community and enzyme activity of two earthworm species during the bioremediation of pentachlorophenol-contaminated soils

“…The natural attenuation therefore often takes years or even decades to occur. Bioaugmentation [5,9] and biostimulation [10], aiming at the addition of exogenous degrading strains or growth substrates, respectively, are viewed as cost-effective and environmentally friendly methods for organic pollution mitigation at industrial sites [11]. These two strategies could significantly improve the existence or activities of PCP degraders, and further accelerate PCP bioremediation.…”

Evaluation ofRicinus communisL. for the Phytoremediation of Polluted Soil with Organochlorine Pesticides

“…In recent years, bioremediation procedures have focused on phytoextraction and phytoremediation to clean up soils contaminated with organic pollutants as polycyclic aromatic hydrocarbons (PAHs) and POPs [ 15 , 16 ]. Recent studies have demonstrated the importance of understanding the relationship between bacterial activity generated by the plant and remediation process of contaminated soil with DDTs and HCHs [ 17 ].…”