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Stimulating soil microorganisms for mineralizing the herbicide isoproturon by means of microbial electroremediating cells.

Rodrigo Quejigo J, Dörfler U, Schroll R, Esteve-Núñez A - Microb Biotechnol (2016)

Bottom Line: Microbial electroremediating cells (MERCs) consist in a variety of bioelectrochemical devices that aim to overcome electron acceptor limitation and maximize metabolic oxidation with the purpose of enhancing the biodegradation of a pollutant in the environment.The objective of this work was to use MERCs principles for stimulating soil bacteria to achieve the complete biodegradation of the herbicide (14) C-isoproturon (IPU) to (14) CO(2) in soils.The remarkable impact of electrodes on the microbial activity of natural communities suggests a promising future for this emerging environmental technology that we propose to name bioelectroventing.

View Article: PubMed Central - PubMed

Affiliation: University of Alcalá, Alcalá de Henares, Madrid, Spain.

No MeSH data available.


Related in: MedlinePlus

A. Cumulative mineralization of 14C‐IPU within 25 days in pol‐MERCs (n = 4, SD) compared with mineralization capability of the soil under the electrode‐free conditions (n = 3, SD). B. Cumulative mineralization and rate of 14CO2 production from 14C‐IPU under long‐term MERCs treatment. During the first phase, the polarized anode acted as TEA at 0.6 V versus Ag/AgCl [+197 mV versus normal hydrogen electrode (NHE)]. This phase ended with the anode potential reversed to −300 mV versus Ag/AgCl for 12 h. During the second phase, the anode potential was achieved by connecting the electrodes through a 56 ohm resistor.
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mbt212351-fig-0001: A. Cumulative mineralization of 14C‐IPU within 25 days in pol‐MERCs (n = 4, SD) compared with mineralization capability of the soil under the electrode‐free conditions (n = 3, SD). B. Cumulative mineralization and rate of 14CO2 production from 14C‐IPU under long‐term MERCs treatment. During the first phase, the polarized anode acted as TEA at 0.6 V versus Ag/AgCl [+197 mV versus normal hydrogen electrode (NHE)]. This phase ended with the anode potential reversed to −300 mV versus Ag/AgCl for 12 h. During the second phase, the anode potential was achieved by connecting the electrodes through a 56 ohm resistor.

Mentions: The first series of experiments started by investigating the influence of a positive potential electrode on the 14C‐IPU mineralization in soil. After the incubation period (25 days), the cumulative mineralization reached the value of 21.3% (average value of four experimental replicates), whereas 14C‐IPU mineralization in the electrode‐free control was below 1% (Fig. 1A). Regarding the low proportion of radiochemical impurities of the 14C‐IPU applied in this series (98% purity), most of the 14CO2 derives from the radiochemical pollutant. Sterile pol‐MERCs were assayed in order to prove that polarized electrodes by themselves were not performing abiotic electro‐oxidation of 14C‐IPU. Actually, the sterilized system (1.49 ± 0.05% mineralization after 25 days of incubation) confirms the mineralization of 14C‐IPU by means of the native microbial population in our soil assays. Interestingly, the cumulative mineralization under both, electrode‐free control and sterile pol‐MERCs were lower than the impurities fraction in our 14C‐IPU (2%).


Stimulating soil microorganisms for mineralizing the herbicide isoproturon by means of microbial electroremediating cells.

Rodrigo Quejigo J, Dörfler U, Schroll R, Esteve-Núñez A - Microb Biotechnol (2016)

A. Cumulative mineralization of 14C‐IPU within 25 days in pol‐MERCs (n = 4, SD) compared with mineralization capability of the soil under the electrode‐free conditions (n = 3, SD). B. Cumulative mineralization and rate of 14CO2 production from 14C‐IPU under long‐term MERCs treatment. During the first phase, the polarized anode acted as TEA at 0.6 V versus Ag/AgCl [+197 mV versus normal hydrogen electrode (NHE)]. This phase ended with the anode potential reversed to −300 mV versus Ag/AgCl for 12 h. During the second phase, the anode potential was achieved by connecting the electrodes through a 56 ohm resistor.
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mbt212351-fig-0001: A. Cumulative mineralization of 14C‐IPU within 25 days in pol‐MERCs (n = 4, SD) compared with mineralization capability of the soil under the electrode‐free conditions (n = 3, SD). B. Cumulative mineralization and rate of 14CO2 production from 14C‐IPU under long‐term MERCs treatment. During the first phase, the polarized anode acted as TEA at 0.6 V versus Ag/AgCl [+197 mV versus normal hydrogen electrode (NHE)]. This phase ended with the anode potential reversed to −300 mV versus Ag/AgCl for 12 h. During the second phase, the anode potential was achieved by connecting the electrodes through a 56 ohm resistor.
Mentions: The first series of experiments started by investigating the influence of a positive potential electrode on the 14C‐IPU mineralization in soil. After the incubation period (25 days), the cumulative mineralization reached the value of 21.3% (average value of four experimental replicates), whereas 14C‐IPU mineralization in the electrode‐free control was below 1% (Fig. 1A). Regarding the low proportion of radiochemical impurities of the 14C‐IPU applied in this series (98% purity), most of the 14CO2 derives from the radiochemical pollutant. Sterile pol‐MERCs were assayed in order to prove that polarized electrodes by themselves were not performing abiotic electro‐oxidation of 14C‐IPU. Actually, the sterilized system (1.49 ± 0.05% mineralization after 25 days of incubation) confirms the mineralization of 14C‐IPU by means of the native microbial population in our soil assays. Interestingly, the cumulative mineralization under both, electrode‐free control and sterile pol‐MERCs were lower than the impurities fraction in our 14C‐IPU (2%).

Bottom Line: Microbial electroremediating cells (MERCs) consist in a variety of bioelectrochemical devices that aim to overcome electron acceptor limitation and maximize metabolic oxidation with the purpose of enhancing the biodegradation of a pollutant in the environment.The objective of this work was to use MERCs principles for stimulating soil bacteria to achieve the complete biodegradation of the herbicide (14) C-isoproturon (IPU) to (14) CO(2) in soils.The remarkable impact of electrodes on the microbial activity of natural communities suggests a promising future for this emerging environmental technology that we propose to name bioelectroventing.

View Article: PubMed Central - PubMed

Affiliation: University of Alcalá, Alcalá de Henares, Madrid, Spain.

No MeSH data available.


Related in: MedlinePlus