Carbon and nitrogen isotope effects associated with the dioxygenation of aniline and diphenylamine

Sarah G. Pati, Kwanghee Shin, Marita Skarpeli-Liati, Jakov Bolotin, Soren N. Eustis, Jim C. Spain, Thomas B. Hofstetter

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

Dioxygenation of aromatic rings is frequently the initial step of biodegradation of organic subsurface pollutants. This process can be tracked by compound-specific isotope analysis to assess the extent of contaminant transformation, but the corresponding isotope effects, especially for dioxygenation of N-substituted, aromatic contaminants, are not well understood. We investigated the C and N isotope fractionation associated with the biodegradation of aniline and diphenylamine using pure cultures of Burkholderia sp. strain JS667, which can biodegrade both compounds, each by a distinct dioxygenase enzyme. For diphenylamine, the C and N isotope enrichment was normal with εC- and εN-values of -0.6 ± 0.1% and -1.0 ± 0.1%, respectively. In contrast, N isotopes of aniline were subject to substantial inverse fractionation (εN of +13 ± 0.5%), whereas the εC-value was identical to that of diphenylamine. A comparison of the apparent kinetic isotope effects for aniline and diphenylamine dioxygenation with those from abiotic oxidation by manganese oxide (MnO2) suggest that the oxidation of a diarylamine system leads to distinct C-N bonding changes compared to aniline regardless of reaction mechanism and oxidant involved. Combined evaluation of the C and N isotope signatures of the contaminants reveals characteristic δδ 15N/δδ13C-trends for the identification of diphenylamine and aniline oxidation in contaminated subsurfaces and for the distinction of aniline oxidation from its formation by microbial and/or abiotic reduction of nitrobenzene.

Original languageEnglish (US)
Pages (from-to)11844-11853
Number of pages10
JournalEnvironmental Science and Technology
Volume46
Issue number21
DOIs
StatePublished - Nov 6 2012

Fingerprint Dive into the research topics of 'Carbon and nitrogen isotope effects associated with the dioxygenation of aniline and diphenylamine'. Together they form a unique fingerprint.

Cite this