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Who Is the Rock Miner and Who Is the Hunter? The Use of Heavy Oxygen Labeled Phosphate (P18O4) to Differentiate between C and P Fluxes in a Benzene-Degrading Consortium
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- Author(s) / Creator(s)
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Phosphorus availability and cycling in microbial
communities is a key determinant of bacterial activity. However,
identifying organisms critical to P cycling in complex biodegrading
consortia has proven elusive. Here we assess a new DNA stable
isotope probing (SIP) technique using heavy oxygen-labeled
phosphate (P18O4) and its effectiveness in pure cultures and a
nitrate-reducing benzene-degrading consortium. First, we successfully labeled pure cultures of Gram-positive Micrococcus luteus and
Gram-negative Bradyrhizobium elkanii and separated isotopically
light and heavy DNA in pure cultures using centrifugal analyses.
Second, using high-throughput amplicon sequencing of 16S rRNA
genes to characterize active bacterial taxa (13C-labeled), we found
taxa like Betaproteobacteria were key in denitrifying benzene
degradation and that other degrading (nonhydrocarbon) inactive taxa (P18O4-labeled) like Staphylococcus and Corynebacterium
may promote degradation through production of secondary metabolites (i.e., “helper” or “rock miner” bacteria). Overall, we
successfully separated active and inactive taxa in contaminated soils, demonstrating the utility of P18O4-DNA SIP for identifying
actively growing bacterial taxa. We also identified potential “miner” bacteria that choreograph hydrocarbon degradation by other
microbes (i.e., the “hunters”) without directly degrading contaminants themselves. Thus, while several taxa degrade benzene
under denitrifying conditions, microbial benzene degradation may be enhanced by both direct degraders and miner bacteria -
- Date created
- 2018-01-01
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- Subjects / Keywords
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- Type of Item
- Article (Published)