Quantification of Bathyarchaeota in Enriched Delaware Sediments

Bathyarchaeota is one of the most abundant phyla of archaea found in marine and estuarine sediments. There are multiple proposed metabolisms for this phylum such as methanogenesis and degradation of proteins, lipids, and polymeric carbons. Understanding why this phylum utilizes so many different metabolisms could give insight to their ecological importance in sediments. In this study, we aimed to identify effective growth additives for Bathyarchaeota in Delaware sediments in order to understand bathyarchaeotal metabolic response. We used QPCR to measure gene copies of the bathyarchaeotal 16S rRNA gene sequence from enriched Delaware sediment cultures. Our study demonstrates that adding an electron carrier to enrichment culture may increase the biomass of Bathyarchaeota in enrichment culture. Other growth additives (casamino acids, lignin, and titanium (III) citrate) show no growth of Bathyarchaeota biomass. Identifying more effective enrichment methods for Bathyarchaeota could improve culture strategies for growing this phylum in a lab setting to potentially sequence full genomes and understand their metabolisms.