TY - JOUR
T1 - Synchronic Biotransformation of 1,4-Dioxane and 1,1-Dichloroethylene by a Gram-Negative Propanotroph Azoarcus sp. DD4
AU - Deng, Daiyong
AU - Li, Fei
AU - Wu, Chen
AU - Li, Mengyan
N1 - Funding Information:
This project was supported by the start-up fund from the Department of Chemistry and Environmental Science at the New Jersey Institute of Technology (NJIT), the U.S. Geological Survey WRRI Program (2018NJ400B), a NJIT Faculty Seed Grant (211247), and the NJIT Undergraduate Research and Innovation (URI) Program. The authors thank Dr. Nir Krakauer from the City College of New York for editing the manuscript.
Publisher Copyright:
© 2018 American Chemical Society.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018/8/14
Y1 - 2018/8/14
N2 - Bioremediation of 1,4-dioxane is strongly challenged by the concurrent contamination of chlorinated solvents, particularly 1,1-dichloroethylene (1,1-DCE), a potent inhibitor of archetypic 1,4-dioxane degraders (e.g., Pseudonocardia and Mycobacterium). Vegetative growth and aggregation behavior of these Gram-positive Actinomycetes also hinder their field application. A new Gram-negative bacterium Azoarcus sp. DD4 was isolated from an activated sludge sample. Notably, DD4 can sustain the concurrent co-oxidation of 1,4-dioxane and 1,1-DCE using propane as the primary substrate without observable formation of clumps. Microcosm assays prepared with source zone groundwater samples from a contaminated site indicated DD4 can efficiently remove dioxane, with the concentration decreasing from an initial value of 10.4 mg/L to <0.4 μg/L within 14 days of incubation. Removal of 1,4-dioxane was partially inhibited when an excessive amount of 1,1-DCE (3.28 ± 0.19 mg/L) was artificially spiked into the microcosms but significantly accelerated immediately after the complete depletion of 1,1-DCE. Furthermore, a gene encoding a putative propane monooxygenase was discovered, which may contribute to the oxidation of propane, 1,4-dioxane, and/or 1,1-DCE. Detection of 2-S-glutathionyl acetate and synchronic dechlorination suggest that DD4 detoxifies its primary metabolite, 1,1-DCE epoxide, via conjugation with glutathione. All these findings indicate the suitability of DD4 as a robust inoculum candidate for in situ bioaugmentation to remediate co-contamination by dioxane and 1,1-DCE.
AB - Bioremediation of 1,4-dioxane is strongly challenged by the concurrent contamination of chlorinated solvents, particularly 1,1-dichloroethylene (1,1-DCE), a potent inhibitor of archetypic 1,4-dioxane degraders (e.g., Pseudonocardia and Mycobacterium). Vegetative growth and aggregation behavior of these Gram-positive Actinomycetes also hinder their field application. A new Gram-negative bacterium Azoarcus sp. DD4 was isolated from an activated sludge sample. Notably, DD4 can sustain the concurrent co-oxidation of 1,4-dioxane and 1,1-DCE using propane as the primary substrate without observable formation of clumps. Microcosm assays prepared with source zone groundwater samples from a contaminated site indicated DD4 can efficiently remove dioxane, with the concentration decreasing from an initial value of 10.4 mg/L to <0.4 μg/L within 14 days of incubation. Removal of 1,4-dioxane was partially inhibited when an excessive amount of 1,1-DCE (3.28 ± 0.19 mg/L) was artificially spiked into the microcosms but significantly accelerated immediately after the complete depletion of 1,1-DCE. Furthermore, a gene encoding a putative propane monooxygenase was discovered, which may contribute to the oxidation of propane, 1,4-dioxane, and/or 1,1-DCE. Detection of 2-S-glutathionyl acetate and synchronic dechlorination suggest that DD4 detoxifies its primary metabolite, 1,1-DCE epoxide, via conjugation with glutathione. All these findings indicate the suitability of DD4 as a robust inoculum candidate for in situ bioaugmentation to remediate co-contamination by dioxane and 1,1-DCE.
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U2 - 10.1021/acs.estlett.8b00312
DO - 10.1021/acs.estlett.8b00312
M3 - Article
AN - SCOPUS:85051553038
SN - 2328-8930
VL - 5
SP - 526
EP - 532
JO - Environmental Science and Technology Letters
JF - Environmental Science and Technology Letters
IS - 8
ER -