@article {2664,
	title = {Illuminating microbial species-specific effects on organic matter remineralization in marine sediments},
	journal = {Environmental Microbiology},
	year = {2019},
	month = {Oct-12-2019},
	issn = {1462-2912},
	doi = {10.1111/1462-2920.14871},
	url = {https://apps.webofknowledge.com/InboundService.do?product=WOS\&Func=Frame\&DestFail=http\%3A\%2F\%2Fwww.webofknowledge.com\&SrcApp=search\&SrcAuth=Alerting\&SID=7Bytr67Z6qAbafBcvVL\&customersID=Alerting\&mode=FullRecord\&IsProductCode=Yes\&AlertId=ab9062f8-b111-4f95-},
	author = {Mahmoudi, Nagissa and Enke, Tim N. and Beaupr{\'e}, Steven R. and Teske, Andreas P. and Cordero, Otto X. and Pearson, Ann}
}
@article {2462,
	title = {Sequential bioavailability of sedimentary organic matter to heterotrophic bacteria},
	journal = {Environmental Microbiology},
	year = {2017},
	month = {Oct-05-2017},
	abstract = {Aquatic sediments harbour diverse microbial communities that mediate organic matter degradation and influence biogeochemical cycles. The pool of bioavailable carbon continuously changes as a result of abiotic processes and microbial activity. It remains unclear how microbial communities respond to heterogeneous organic matrices and how this ultimately affects heterotrophic respiration. To explore the relationships between the degradation of mixed carbon substrates and microbial activity, we incubated batches of organic-rich sediments in a novel bioreactor (IsoCaRB) that permitted continuous observations of CO2 production rates, as well as sequential sampling of isotopic signatures (δ13C, Δ14C), microbial community structure and diversity, and extracellular enzyme activity. Our results indicated that lower molecular weight (MW), labile, phytoplankton-derived compounds were degraded first, followed by petroleum-derived exogenous pollutants, and finally by higher MW polymeric plant material. This shift in utilization coincided with a community succession and increased extracellular enzyme activities. Thus, sequential utilization of different carbon pools induced changes at both the community and cellular level, shifting community composition, enzyme activity, respiration rates, and residual organic matter reactivity. Our results provide novel insight into the accessibility of sedimentary organic matter and demonstrate how bioavailability of natural organic substrates may affect the function and composition of heterotrophic bacterial populations.},
	doi = {10.1111/1462-2920.13745},
	url = {http://doi.wiley.com/10.1111/1462-2920.13745http://onlinelibrary.wiley.com/wol1/doi/10.1111/1462-2920.13745/fullpdfhttps://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2F1462-2920.13745},
	author = {Mahmoudi, Nagissa and {\'e}, Steven R. and Steen, Andrew D. and Pearson, Ann}
}
@article { ISI:000386966700005,
	title = {IsoCaRB: A novel bioreactor system to characterize the lability and natural carbon isotopic (C-14, C-13) signatures of microbially respired organic matter},
	journal = {LIMNOLOGY AND OCEANOGRAPHY-METHODS},
	volume = {14},
	number = {{10}},
	year = {2016},
	month = {OCT},
	pages = {668-681},
	type = {Article},
	abstract = {Organic matter is the dominant pool of reduced carbon in marine and freshwater systems. Mineralization of organic matter is largely attributed to complex and diverse microbial communities that mediate degradation and ultimately yield the terminal respiratory product, carbon dioxide (CO2). The factors that constrain the lability and degradation of organic matter remain unclear, but they involve a complex interplay between structural and chemical properties of the compounds, physical properties of the matrices, and the functional potential of the microorganisms that are present. To investigate these relationships, we developed a novel bioreactor system-called Isotopic Carbon Respirometer-Bioreactor (IsoCaRB)-that permits real-time monitoring of microbial CO2 production rates and collects sequential samples of this CO2 for off-line isotopic analyses (C-13, C-14). Application of this system to organic-rich sediments from Salt Pond, MA reveals that organic matter is oxidized both abiotically and microbially, and that the pattern of microbial respiration by the native sediment community is complex, accessing different carbon substrates over the course of incubation. Isotopic measurements show modern organic matter of progressively older ages (<= ca. 50 yr) is consumed, and this material has variable origins (salt marsh grasses, terrestrial, and marine organic matter). Collectively, the IsoCaRB system provides coupled insights into the sources, ages, and inherent biological and abiotic reactivity of natural organic matter.},
	issn = {1541-5856},
	doi = {10.1002/lom3.10121},
	author = {Beaupr{\'e}, Steven R. and Mahmoudi, Nagissa and Pearson, Ann}
}
@article {91,
	title = {Assessing microbial carbon sources and potential PAH degradation using natural abundance 14C analysis},
	journal = {Environmental Pollution},
	volume = {175},
	year = {2013},
	note = {id: 2268},
	pages = {125-130},
	abstract = {Natural abundance 14C 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. Δ14C of microbial phospholipid fatty acids (PLFA) at the site ranged from +54{\textperthousand} to -697{\textperthousand}. 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 14C analysis as a tool to elucidate microbial carbon sources.},
	issn = {0269-7491},
	doi = {10.1016/j.envpol.2012.12.020},
	url = {http://www.sciencedirect.com/science/article/pii/S0269749112005453},
	author = {Mahmoudi, Nagissa and Fulthorpe, Roberta R. and Burns, Leanne and Mancini, Silvia and Slater, Greg F.}
}
