Accumulation, distribution and transformation of DDT and PCBs by Phragmites australis and Oryza sativa L.: II. Enzyme study

Abstract

Two wetland plant species, Phragmites australis and Oryza sativa, were grown in a glasshouse under hydroponics conditions. Enzyme extracts from different parts of the plants were used to determine the transformation rate of o,p'-DDT, p,p'-DDT and PCBs. The organic pollutants were directly spiked into the enzyme extracts, and samples were collected every 30 min and analyzed with a GC-ECD. Root extracts of P. australis readily degraded and transformed DDT and some PCB congeners with a low degree of chlorination. In contrast, crude extracts of O. sativa showed no appreciable degradation or transformation of DDT or PCBs. Inhibition studies indicated that the degradation and transformation of both DDT and PCBs by P. australis enzymes were partly mediated by peroxidase and the plant P-450 system. PCBs with a high degree of chlorination were highly resistant to transformation or degradation by plant enzymes. Both wetland plant species accumulated substantial quantities of the persistent organic chemicals but had different degradation capacities. The enzyme systems in P. australis were much more effective that those in rice in the degradation and transformation of the organic pollutants.

The use of a hybrid Sequential Biofiltration System for the improvement of nutrient removal and PCB control in municipal wastewater

“…Chu et al . 55 found P . australis possess enzymes degrading PCB with up to three chlorine atoms, while higher chlorinated congeners were not transformed.…”

Phytomediated Biostimulation of the Autochthonous Bacterial Community for the Acceleration of the Depletion of Polycyclic Aromatic Hydrocarbons in Contaminated Sediments

“…However, as also previously assessed, plant exudates might increase their bioavailability. In the frame of the results obtained here and considering that P. australis has been described as capable of absorbing chemical structures such as DDT, PCB [42], and nonylphenols [9], a role of the bacterial root endophytes in the recorded lack of quantization of PAHs in plant tissues cannot be excluded. Bacterial endophytes are reported as capable of significantly reducing evapotranspiration of toluene through aerial parts [43], as well as responsible for the degradation of naphthalene when the inoculated plants were grown in the naphthalene amended soil [44].…”

Uptake of Xenobiotics from Polluted Waters by Plants

“…Phytoremediation approach can be efficient in agricultural countries, with the aim to avoid contamination of aquatic environment. Examples include utilization of Salvia minima for pig farm wastewaters in Mexico (Olguin et al 2007), livestock wastewaters in China ), dairy wastewater (Healy et al 2007;Munoz et al 2006), fluorinated agrochemicals (Reinhold and Saunders 2006), pesticides , herbicides (Schröder et al 2005), diazinon (Moore et al 2007) and DDT (Chu et al 2006).…”