oa Drivers of Lipid Remodeling in Marine Microbial Communities – A Mesocosm Approach

While it is known that microbes can remodel their lipidome in response to environmental stress (lipid remodeling), the application of lipids in oceanography has been limited to the study of source and metabolic relationships. However, recent advances in lipidomics now allow the use of lipids as indicators of microbial adaptation to environmental change. This presentation will examine lipid remodeling in natural microbial communities exposed to multiple environmental stressors in a mesocosm experiment. We test the overarching hypothesis that we can distinct between changes in lipidome caused by varying biological sources and physiological adaptation of source organisms. This presentation will study changes in the pool of intact polar lipids (IPLs) of a microbial community exposed to multi-environmental stressors during a 2-month-long mesocosm experiment. We investigate lipid remodeling in response to changing nutrient stoichiometries, temperature, pH, and light availability in surface and subsurface water masses with contrasting redox potentials, using multiple linear regressions, classification and regression trees, and random forest analyses. We will show how the observed statistical relationships between IPL distributions, physical-chemical parameters, and the composition of the microbial community suggest evidence of lipid remodeling in response to environmental stressors with implications for ocean biogeochemistry under future scenarios of climate change.