Baltic Sea Basin Paleoenvironment Metagenome

The microbiological goals of IODP Expedition 347, Baltic Sea Paleoenvironment, include determining 1. The differences in microbial community structure between this shallow intracontinental sea and deep-ocean communities and 2. If the microbial communities reflect the depositional conditions, i.e., limnic versus marine, or are due to modern selective pressures. Previous tag sequencing efforts by CoDL showed that Bacteria assigned to the Chloroflexi and Actinobacteria phyla were prevalent in most samples sequenced, and Archaea related to Bathyarchaeota dominated the majority of samples sequenced. These data suggest that dehalogenation, fermentation, and nitrogen cycling could be key metabolic functions in the marine deep subsurface in the Baltic Sea Basin. However, determining the roles of microbes in the shallow sediment is critical to understanding the factors that influence adaptation early after burial, and potential functions of the deep sedimentary biosphere. We propose to sequence three metagenomes that would complement the previous CoDL 16S dataset, as well as the metatranscriptomes already in progress. These shallow metagenomes are crucial to accurately describe and compare microbial community responses to deep biosphere conditions. PI Brandi Kiel Reese, Texas A and M University-Corpus Christi