Category: New publications

Our full text, open-access, manuscript is now available from Frontiers in Microbiology.  Thanks to Gordon Taylor and his team for putting together a great project:

Taylor, G. T., E. A. Suter, Z. Q. Li, S. Chow, D. Stinton, T. Zaliznyak, and S. R. Beaupré. (2017). Single-Cell Growth Rates in Photoautotrophic Populations Measured by Stable Isotope Probing and Resonance Raman Microspectrometry. Frontiers in Microbiology 8. http://doi.org/10.3389/fmicb.2017.01449

Abstract: “A new method to measure growth rates of individual photoautotrophic cells by combining stable isotope probing (SIP) and single-cell resonance Raman microspectrometry is introduced. This report explores optimal experimental design and the theoretical underpinnings for quantitative responses of Raman spectra to cellular isotopic composition. Resonance Raman spectra of isogenic cultures of the cyanobacterium, Synechococcus sp., grown in ¹³C-bicarbonate revealed linear covariance between wavenumber (cm⁻¹) shifts in dominant carotenoid Raman peaks and a broad range of cellular ¹³C fractional isotopic abundance. Single-cell growth rates were calculated from spectra-derived isotopic content and empirical relationships. Growth rates among any 25 cells in a sample varied considerably; mean coefficient of variation, CV, was 29 ± 3% (σ/x), of which only ~2% was propagated analytical error. Instantaneous population growth rates measured independently by in vivo fluorescence also varied daily (CV ≈ 53%) and were statistically indistinguishable from single-cell growth rates at all but the lowest levels of cell labeling. SCRR censuses of mixtures prepared from Synechococcus sp. and T. pseudonana (a diatom) populations with varying ¹³C-content and growth rates closely approximated predicted spectral responses and fractional labeling of cells added to the sample. This approach enables direct microspectrometric interrogation of isotopically- and phylogenetically-labeled cells and detects as little as 3% changes in cellular fractional labeling. This is the first description of a non-destructive technique to measure single-cell photoautotrophic growth rates based on Raman spectroscopy and well-constrained assumptions, while requiring few ancillary measurements.”

How do you measure the growth rates of single cells?  With lasers and isotopes, of course!  Just ask Prof. Gordon Taylor and his team at SoMAS.  Or, better yet, read our newly accepted manuscript:

Taylor G. T., Suter E. A., Li Z. Q., Chow S., Stinton D., Zaliznyak T. and Beaupré S. R. (2017). Single-Cell Growth Rates in Photoautotrophic Populations Measured by Stable Isotope Probing and Resonance Raman Microspectrometry. Frontiers in Microbiology. Available at: http://doi.org/10.3389/fmicb.2017.01449

For more information on Raman measurements at Stony Brook University, please visit Prof. Taylor’s NAno-RAMAN Molecular Imaging Laboratory website

Price R. E. and Giovannelli D. (2017) A Review of the Geochemistry and Microbiology of Marine Shallow-Water Hydrothermal Vents. In Reference Module in Earth Systems and Environmental Sciences Elsevier. Available at: https://doi.org/10.1016/B978-0-12-409548-9.09523-3

Congratulations to friends of the lab, Joel Hurowitz (Stony Brook University) and Woody Fischer (Caltech), on their most recent publication:

Hurowitz, J. A., Grotzinger, J. P., Fischer, W. W., McLennan, S. M., Milliken, R. E., Stein, N., et al. (2017). Redox stratification of an ancient lake in Gale crater, Mars. Science, 356(6341), eaah6849. http://doi.org/10.1126/science.aah6849

Curious?  Check out our new paper in Environmental Microbiology:

Mahmoudi, N., Beaupré, S. R., Steen, A. D., & Pearson, A. (2017). Sequential bioavailability of sedimentary organic matter to heterotrophic bacteria. Environmental Microbiology. http://doi.org/10.1111/1462-2920.13745