| SS4.02 Ecology and Physiology of Marine Organisms: Insights from Genes, Genomes, and Proteomes |
| Dollhopf, S, L, Florida State University, Tallahassee, USA, sdollhop@mailer.fsu.edu |
| Smith, A, C, Florida State University, Tallahassee, USA, agold@ocean.fsu.edu |
| Hunter, E, , Florida State University, Tallahassee, USA, ehunter@ocean.fsu.edu |
| Kostka, J, E, Florida State University, Tallahassee, USA, jkostka@ocean.fsu.edu |
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| QUANTIFICATION OF SULFATE- AND IRON(III)-REDUCING BACTERIA WITH REVERSE TRANSCRIPTION REAL-TIME PCR IN BIOTURBATED AND NONBIOTURBATED SALTMARSH SEDIMENTS |
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| Sulfate and iron(III) minerals are the predominant terminal electron acceptors utilized during organic matter decomposition in southeastern saltmarsh sediments. Depending upon the Fe(III) supply, which is effected by bioturbation, iron(III)-reduction can comprise > 50 percent of total sediment carbon oxidation; however, very little is known about the ecology of marine iron(III)-reducing bacteria (FeRB). FeRB were characterized from bioturbated [iron(III)-rich] and nonbioturbated [iron(III)-poor] sediments by cloning and sequencing of 16S rRNA genes from the highest positive dilutions of a most probable number enrichment culture assay. Gene sequences most closely related to uncultured members of the Geobacteraceae family were predominant amongst sequences retrieved from all iron(III)-reducing enrichments. PCR primers specific for these 16S rRNA genes and other phylogenetic groups of known sulfate and iron(III)-reducing bacteria were designed and tested for reverse transcription real-time PCR. The specificity and efficiency of these primer sets was determined empirically and used to quantify the relative abundance of the different phylogenetic groups in depth profiles of bioturbated and nonbioturbated sediment, as well as in radial profiles from macrofaunal burrows and the root zone of Spartina alterniflora. |
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