Widespread distribution of soluble di-iron monooxygenase (SDIMO) genes in Arctic groundwater impacted by 1,4-dioxane

Li, M; Mathieu, J; Yang, Y; Fiorenza, S; Deng, Y; He, Z; Zhou, J; Alvarez, PJ

HERO ID

3538108

Reference Type

Journal Article

Year

2013

Language

English

PMID

23909410

HERO ID 3538108
In Press No
Year 2013
Title Widespread distribution of soluble di-iron monooxygenase (SDIMO) genes in Arctic groundwater impacted by 1,4-dioxane
Authors Li, M; Mathieu, J; Yang, Y; Fiorenza, S; Deng, Y; He, Z; Zhou, J; Alvarez, PJ
Journal Environmental Science & Technology
Volume 47
Issue 17
Page Numbers 9950-9958
Abstract Soluble di-iron monooxygenases (SDIMOs), especially group-5 SDIMOs (i.e., tetrahydrofuran and propane monooxygenases), are of significant interest due to their potential role in the initiation of 1,4-dioxane (dioxane) degradation. Functional gene array (i.e., GeoChip) analysis of Arctic groundwater exposed to dioxane since 1980s revealed that various dioxane-degrading SDIMO genes were widespread, and PCR-DGGE analysis showed that group-5 SDIMOs were present in every tested sample, including background groundwater with no known dioxane exposure history. A group-5 thmA-like gene was enriched (2.4-fold over background, p < 0.05) in source-zone samples with higher dioxane concentrations, suggesting selective pressure by dioxane. Microcosm assays with (14)C-labeled dioxane showed that the highest mineralization capacity (6.4 ± 0.1% (14)CO2 recovery during 15 days, representing over 60% of the amount degraded) corresponded to the source area, which was presumably more acclimated and contained a higher abundance of SDIMO genes. Dioxane mineralization ceased after 7 days and was resumed by adding acetate (0.24 mM) as an auxiliary substrate to replenish NADH, a key coenzyme for the functioning of monoxygenases. Acetylene inactivation tests further corroborated the vital role of monooxygenases in dioxane degradation. This is the first report of the prevalence of oxygenase genes that are likely involved in dioxane degradation and suggests their usefulness as biomarkers of dioxane natural attenuation.
Doi 10.1021/es402228x
Pmid 23909410
Wosid WOS:000330094700050
Url https://www.proquest.com/scholarly-journals/widespread-distribution-soluble-di-iron/docview/1431088161/se-2?accountid=171501
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword NAD (coenzyme); acetates; acetylene; biomarkers; dioxane; groundwater; isotope labeling; mineralization; propane; radionuclides; tetrahydrofuran; Arctic region