265-10 Biomarker Analysis of Phototrophs in Fayetteville Green Lake, NY

See more from this Division: Topical Sessions
See more from this Session: Lakes in Extreme Environments: Earth and Beyond

Tuesday, 7 October 2008: 4:00 PM
George R. Brown Convention Center, 330A

Derek Smith and James Scott, Earth Sciences, Dartmouth College, Hanover, NH
Abstract:
Fayetteville Green Lake, NY's individual sulfur cycle has a major impact upon the prevailing ecosystem of the lake and provides an analog for an ancient marine euxinic water column. This work focuses upon the extraction of biomarkers and organics from the sulfidic sediments of the lake, the analysis and resolution of differences in these hydrocarbon structures through gas chromatography-mass spectroscopy (GC-MS), and the resolution of differences in the isotopic fractionation of these compound specific biomarkers using isotope ratio-gas chromatography-mass spectroscopy (IR-GC-MS) and isotope ratio-gas chromatograph-complete combustion-mass spectroscopy (IR-GC-CC-MS). Carotenoids are a wide range of highly unsaturated C40 compounds that are produced primarily by photosynthetic organisms. Found exclusively in Chromatiaceae, the purple sulfur anoxygenic photosynthesizing bacteria is the red pigment okenone, with an okenane skeleton. The 2α-methylhopanes appear to be a specific hydrocarbon used to identify oxygenic photosynthesizing cyanobacteria. Through a thorough analysis of the relative abundance of these two hydrocarbons remaining in the sediment, accurate descriptions of past photosynthetic activities and communities are drawn.

See more from this Division: Topical Sessions
See more from this Session: Lakes in Extreme Environments: Earth and Beyond