@article {2977,
	title = {Subsurface Microbial Community Composition in Anchialine Environments Is Influenced by Original Organic Carbon Source at Time of Deposition},
	journal = {Frontiers in Marine Science},
	volume = {9},
	year = {2022},
	month = {04/2022},
	pages = {1-13},
	abstract = {Prokaryotes constitute the majority of sedimentary biomass, where they cycle organic carbon and regulate organic matter transformation. The microbes inhabiting sediment are diverse and the factors controlling microbial community composition are not fully understood. Here, we characterized the prokaryotic community using 16S rRNA gene sequencing in 24 stratigraphic layers within a 89 cm (dated to 1900 years old) sediment core from an anchialine sinkhole in the Bahamas with a stratified water column and anoxic bottom water. The microbial community was dominated by members of the Alphaproteobacteria, Dehalococcoidia, Gammaproteobacteria, Bathyarchaeota, and Campylobacter classes. Most interestingly, subsurface microbial community structure could be correlated to previous evidence for timewise changes in the main source of organic matter that was supplied to the sediment accumulating during the last 2000 years, which itself was caused by regional terrestrial vegetation changes. The C:N ratio was correlated to the relative abundance of the microbial classes, and the microbial communities followed three previously determined time periods based on the source of organic matter, which suggests that the carbon source at time of deposition influences the resultant subsurface microbial community composition. These results show that carbon source is a driver of the microbial community composition inhabiting anoxic sediment, which could have implications for improving understanding of carbon cycling in coastal sedimentary basins.},
	doi = {10.3389/fmars.2022.872789},
	url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.872789/full},
	author = {Risley, Catherine A. and Tamalavage, Anne E. and van Hengstum, Peter J. and Labonte, Jessica M.}
}
@article {23,
	title = {Single cell genomics indicates horizontal gene transfer and viral infections in a deep subsurface Firmicutes population},
	journal = {Frontiers in Microbiology},
	volume = {6},
	year = {2015},
	note = {PT: J; TC: 0; UT: WOS:000352551600004},
	pages = {349-349},
	abstract = {A major fraction of Earth{\textquoteright}s prokaryotic biomass dwells in the deep subsurface, where cellular abundances per volume of sample are lower, metabolism is slower, and generation times are longer than those in surface terrestrial and marine environments. How these conditions impact biotic interactions and evolutionary processes is largely unknown. Here we employed single cell genomics to analyze cell-to-cell genome content variability and signatures of horizontal gene transfer (HGT) and viral infections in five cells of Candidatus Desulforudis audaxviator, which were collected from a three km-deep fracture water in the 2.9 Ga-old Witwatersrand Basin of South Africa. Between 0 and 32 \% of genes recovered from single cells were not present in the original, metagenomic assembly of Desulforudis, which was obtained from a neighboring subsurface fracture. We found a transposable prophage, a retron, multiple clustered regularly interspaced short palindromic repeats (CRISPRs) and restriction-modification systems, and an unusually high frequency of transposases in the analyzed single cell genomes. This indicates that recombination, HGT and viral infections are prevalent evolutionary events in the studied population of microorganisms inhabiting a highly stable deep subsurface environment.},
	issn = {1664-302X},
	doi = {10.3389/fmicb.2015.00349},
	author = {Labonte, Jessica M. and Field, Erin K. and Lau, Maggie and Chivian, Dylan and Van Heerden, Esta and Wommack, K. Eric and Kieft, Thomas L. and Onstott, Tullis C. and Stepanauskas, Ramunas}
}
