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Lookup NU author(s): Dr Paola Meynet,
Professor Russell Davenport
This is the authors' accepted manuscript of an article that has been published in its final definitive form by ACS Publications, 2020.
For re-use rights please refer to the publisher's terms and conditions.
Temperature is a key factor that influences chemical biotransformation potential and rates, on which exposure and fate models rely to predict the environmental (micro)pollutant fate. Arrhenius-based models are currently implemented in environmental exposure assessment to adapt biotransformation rates to actual temperatures, assuming validity in the 0-30 °C range. However, evidence on how temperature shifts affect the physicochemical and microbial features in biological systems is scarce, questioning the validity of the existing modeling approaches. In this work, laboratory-scale batch assays were designed to investigate how a mixed microbial community responds to short-term temperature shifts, and how this impacts its ability to biotransform a range of structurally diverse micropollutants. Our results revealed three distinct kinetic responses at temperatures above 20 °C, mostly deviating from the classic Arrhenius-type behavior. Micropollutants with similar temperature responses appeared to undergo mostly similar initial biotransformation reactions, with substitution-type reactions maintaining Arrhenius-type behavior up to higher temperatures than oxidation-type reactions. Above 20 °C, the microbial community also showed marked shifts in both composition and activity, which mostly correlated with the observed deviations from Arrhenius-type behavior, with compositional changes becoming a more relevant factor in biotransformations catalyzed by more specific enzymes (e.g., oxidation reactions). Our findings underline the need to re-examine and further develop current environmental fate models by integrating biological aspects, to improve accuracy in predicting the environmental fate of micropollutants.
Author(s): Meynet P, Davenport RJ, Fenner K
Publication type: Article
Publication status: Published
Journal: Environmental Science and Technology
Online publication date: 08/09/2020
Acceptance date: 08/09/2020
Date deposited: 24/11/2020
ISSN (print): 0013-936X
ISSN (electronic): 1520-5851
Publisher: ACS Publications
PubMed id: 32897072
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