@article{f8f27197d7f34f188a8aa047e8ce97f6,
title = "Lacustrine brGDGT response to microcosm and mesocosm incubations",
abstract = "Branched dialkyl glycerol tetraethers (brGDGTs) are increasingly used as a paleotemperature proxy, yet the microbial producers of these compounds and the way they respond to environmental perturbations remain poorly understood. In this work, we used mesocosms to track the evolution of brGDGTs over several months, as well as an array of microcosms to study microbial brGDGT response to oxygen availability and carbon source. Overall our results confirm that brGDGTs are produced in the water column and respond to environmental perturbation. brGDGT concentrations increase in response to low oxygen, in agreement with empirical observations, but respond to added carbon only when ambient nutrients are low. Slow adjustment to temperature changes from the field to the laboratory appears to have influenced the relative methylation and isomerization of brGDGTs in the mesocosms. Overall our work is consistent with the inference that the producers are facultative aerobic heterotrophic organisms. Our results demonstrate that the use of micro- and mesocosms is a viable option to study brGDGTs in real time and help better understand this biomarker as a paleoproxy.",
keywords = "Lakes, Mesocosm, Microcosm, brGDGTs",
author = "Pablo Mart{\'i}nez-Sosa and Tierney, {Jessica E.}",
note = "Funding Information: We would like to acknowledge Paul Zander and Patrick Murphy for their help with the lipid analysis in the Organic Geochemistry Laboratory at the University of Arizona. We would also like to thank Laura Meredith for her assistance and providing the facilities for part of the microcosm incubations at the BIO5 Institute, and Isla Casta{\~n}eda from the University of Massachusetts Amherst for her valuable comments on the manuscript. The comments of two anonymous reviewers greatly improved this work. This research was funded by the National Science Foundation , grant EAR-1603674 and by CONACYT through the student scholarship 440897 . Funding Information: We would like to acknowledge Paul Zander and Patrick Murphy for their help with the lipid analysis in the Organic Geochemistry Laboratory at the University of Arizona. We would also like to thank Laura Meredith for her assistance and providing the facilities for part of the microcosm incubations at the BIO5 Institute, and Isla Casta{\~n}eda from the University of Massachusetts Amherst for her valuable comments on the manuscript. The comments of two anonymous reviewers greatly improved this work. This research was funded by the National Science Foundation, grant EAR-1603674 and by CONACYT through the student scholarship 440897. Publisher Copyright: {\textcopyright} 2018 Elsevier Ltd",
year = "2019",
month = jan,
doi = "10.1016/j.orggeochem.2018.10.011",
language = "English (US)",
volume = "127",
pages = "12--22",
journal = "Organic Geochemistry",
issn = "0146-6380",
publisher = "Elsevier Limited",
}