title: Correlation between viral production and carbon mineralization under nitrate-reducing conditions in aquifer sediment.
abstract: A variety of microbially mediated metabolic pathways impact biogeochemical cycling in terrestrial subsurface environments. However, the role that viruses have in influencing microbial mortality and microbial community structure is poorly understood. Here we investigated the production of viruses and change in microbial community structure within shallow alluvial aquifer sediment slurries amended with (13)C-labeled acetate and nitrate. Biostimulation resulted in production of viruses concurrent with acetate oxidation, (13)CO2 production and nitrate reduction. Interestingly, change in viral abundance was positively correlated to acetate consumption (r(2)=0.6252, P<0.05) and (13)CO2 production (r(2)=0.6572, P<0.05); whereas change in cell abundance was not correlated to acetate consumption or (13)CO2 production. Viral-mediated cell lysis has implications for microbial community structure. Betaproteobacteria predominated microbial community composition (62% of paired-end reads) upon inoculation but decreased in relative abundance and was negatively correlated to changes in viral abundance (r(2)=0.5036, P<0.05). As members of the Betaproteobacteria decreased, Gammaproteobacteria, specifically Pseudomonas spp., increased in relative abundance (82% of paired-end reads) and was positively correlated with the change in viral abundance (r(2)=0.5368, P<0.05). A nitrate-reducing bacterium, Pseudomonas sp. strain Alda10, was isolated from these sediments and produced viral-like particles with a filamentous morphology that did not result in cell lysis. Together, these results indicate that viruses are linked to carbon biogeochemistry and community structure in terrestrial subsurface sediments. The subsequent cell lysis has the potential to alter available carbon pools in subsurface environments, additionally controlling microbial community structure from the bottom-up.
authors.affiliation: School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: Donald
authors.initials: D
authors.lastname: Pan
authors.affiliation: School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Watson
authors.affiliation: School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: Dake
authors.initials: D
authors.lastname: Wang
authors.affiliation: School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: Zheng Huan
authors.initials: ZH
authors.lastname: Tan
authors.affiliation: Water Sciences Laboratory, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Snow
authors.affiliation: 1] School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA [2] Department of Earth and Atmospheric Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: Karrie A
authors.initials: KA
authors.lastname: Weber
mesh_terms: D000085:Acetates / Q000378:metabolism; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism; D020562:Betaproteobacteria / Q000302:isolation & purification; D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D020563:Gammaproteobacteria / Q000302:isolation & purification; D019015:Geologic Sediments / Q000382:microbiology* / Q000821:virology; D060587:Groundwater; D009566:Nitrates / Q000378:metabolism*; D010084:Oxidation-Reduction; D018406:Virus Physiological Phenomena
chemical_list: D000085:Acetates; D009566:Nitrates; D002245:Carbon Dioxide; D002244:Carbon