Bacterial incorporation of relict carbon in the hydrothermal environment of Guaymas Basin Export

@article{citeulike:619784, abstract = {Radiocarbon analyses of bulk carbon and individual organic compounds are presented for the hydrothermal environment of the Rebecca's Roost vent in the southern trough of the Guaymas Basin hydrothermal field. The [Delta]14C values of CO2 and CH4in the hottest hydrothermal fluids (317[deg]C) are nearly "radiocarbon dead" (-944[per mille sign] and -923[per mille sign], respectively). In contrast, the [Delta]14C values of sediments and individual fatty acids (-418[per mille sign] to -227[per mille sign]) obtained from a bacterial mat located south of the vent site are similar to values previously reported for hydrothermal petroleum in this environment and are more depleted in 14C than overlying waters. Hydrothermal fluids moving through the sediments appear to supply 14C of intermediate age to the bacteria. This carbon may take the form of, or may be supplied by processes similar to, the generation of hydrothermal petroleum. Although the bacterial mat visibly was dominated by Beggiatoa spp., such mats are known to include numerous other species. Individual compound data show that preaged carbon is being consumed by the integrated bacterial assemblage. Values of [delta]13C and [Delta]14C indicate that petroleum-derived carbon is incorporated directly into fresh bacterial biomass. Subsequently, some of this newly synthesized material also is consumed by heterotrophs, as eukaryotic sterols from the same sample also have 14C-depleted values ([Delta]14C = -136[per mille sign] to -110[per mille sign]). Therefore, the entire system may operate as a complex consortium to transform relict carbon back into biomass. Bacterial consumption of relict carbon occurs despite the ample supply of fresh carbon delivered from the productive, overlying water column.}, author = {Pearson, A. and Seewald, J. S. and Eglinton, T. I.}, citeulike-article-id = {619784}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.gca.2005.07.007}, citeulike-linkout-1 = {http://www.sciencedirect.com/science/article/B6V66-4HW80JN-9/2/b2dd24ecf93265cc1cd0e4b78be9955d}, day = {1}, doi = {10.1016/j.gca.2005.07.007}, journal = {Geochimica et Cosmochimica Acta}, keywords = {bacteria, guaymas, hydrothermal}, month = {December}, number = {23}, pages = {5477--5486}, posted-at = {2006-05-09 02:14:43}, priority = {2}, title = {Bacterial incorporation of relict carbon in the hydrothermal environment of Guaymas Basin}, url = {http://dx.doi.org/10.1016/j.gca.2005.07.007}, volume = {69}, year = {2005} }

TY - JOUR ID - citeulike:619784 L3 - citeulike-article-id:619784 N2 - Radiocarbon analyses of bulk carbon and individual organic compounds are presented for the hydrothermal environment of the Rebecca's Roost vent in the southern trough of the Guaymas Basin hydrothermal field. The [Delta]14C values of CO2 and CH4in the hottest hydrothermal fluids (317[deg]C) are nearly "radiocarbon dead" (-944[per mille sign] and -923[per mille sign], respectively). In contrast, the [Delta]14C values of sediments and individual fatty acids (-418[per mille sign] to -227[per mille sign]) obtained from a bacterial mat located south of the vent site are similar to values previously reported for hydrothermal petroleum in this environment and are more depleted in 14C than overlying waters. Hydrothermal fluids moving through the sediments appear to supply 14C of intermediate age to the bacteria. This carbon may take the form of, or may be supplied by processes similar to, the generation of hydrothermal petroleum. Although the bacterial mat visibly was dominated by Beggiatoa spp., such mats are known to include numerous other species. Individual compound data show that preaged carbon is being consumed by the integrated bacterial assemblage. Values of [delta]13C and [Delta]14C indicate that petroleum-derived carbon is incorporated directly into fresh bacterial biomass. Subsequently, some of this newly synthesized material also is consumed by heterotrophs, as eukaryotic sterols from the same sample also have 14C-depleted values ([Delta]14C = -136[per mille sign] to -110[per mille sign]). Therefore, the entire system may operate as a complex consortium to transform relict carbon back into biomass. Bacterial consumption of relict carbon occurs despite the ample supply of fresh carbon delivered from the productive, overlying water column. IS - 23 JF - Geochimica et Cosmochimica Acta EP - 5486 TI - Bacterial incorporation of relict carbon in the hydrothermal environment of Guaymas Basin VL - 69 SP - 5477 KW - bacteria KW - guaymas KW - hydrothermal AU - Pearson, A AU - Seewald, JS AU - Eglinton, TI PY - 2005/12/01/ UR - http://dx.doi.org/10.1016/j.gca.2005.07.007 ER -