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Updated: May 14, 2026

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses
Published on: October 21, 2016
Assessing microbial carbon sources and potential PAH degradation using natural abundance 14C analysis
Nagissa Mahmoudi1, Roberta R Fulthorpe, Leanne Burns
1School of Geography and Earth Sciences, McMaster University, 1280 Main St. W., Hamilton, ON L8S 4K1, Canada.
Abstract:
Natural abundance (14)C analysis was applied to PLFAs collected from an industrial site in southern Ontario in order to assess microbial carbon sources and potential PAH biodegradation in soils. Δ(14)C of microbial phospholipid fatty acids (PLFA) at the site ranged from +54‰ to -697‰. Comparison of these values to surrounding carbon sources found that microbial carbon sources were derived primarily from vegetation and/or natural organic matter present in the soils rather than PAHs. This study highlights that microbes are able to utilize almost all available pools of organic matter including older pools which are thought to contain recalcitrant compounds. Furthermore, it shows that even with the presence of an active microbial community, there may be little biodegradation of PAHs. This study illustrates challenges in assessing microbial activity in the environment and the advantage of using natural abundance (14)C analysis as a tool to elucidate microbial carbon sources.
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