Phylogenetic constraints on elemental stoichiometry and resource allocation in heterotrophic marine bacteria

Abstract

Summary The objective of this study was to evaluate the contribution of evolutionary history to variation in the biomass stoichiometry and underlying biochemical allocation patterns of heterotrophic marine bacteria. We hypothesized that phylogeny significantly constrains biochemical allocation strategy and elemental composition among taxa of heterotrophic marine bacteria. Using a ‘common‐garden’ experimental design, we detected significant interspecific variation in stoichiometry, macromolecule allocation and growth rate among 13 strains of marine Proteobacteria. However, this variation was not well explained by 16S rRNA phylogenetic relationships or differences in growth rate. Heterotrophic bacteria likely experience C‐limitation when consuming resources in Redfield proportions, which consequently decouples growth rate from allocation to rRNA and biomass P content. Accordingly, overall bacterial C : nutrient ratios (C : P = 77, C : N = 4.9) were lower than Redfield proportions, whereas the average N : P ratio of 17 was consistent with the Redfield ratio. Our results suggest that strain‐level diversity is an important driver of variation in the C : N : P ratios of heterotrophic bacterial biomass and that the potential importance of non‐nucleic acid pools of P warrants further investigation. Continued work clarifying the range and controls on the stoichiometry of heterotrophic marine bacteria will help improve understanding and predictions of global ocean C, N and P dynamics.

Interactions between growth-dependent changes in cell size, nutrient supply and cellular elemental stoichiometry of marine Synechococcus

“…Cells were lysed with a bead-beater containing 1 ml of a mixed solution containing one part RNA preservation solution (20 mM ethylenediaminetetraacetic acid; 25 mM sodium citrate; and saturated with ammonium sulfate) and four parts 5 mM Tris buffer. Nucleic acids were measured in the supernatant with the Qubit dsDNA HS Assay Kit and the Qubit HS RNA Assay Kit (Invitrogen, Eugene, OR, USA) according to the method described by Zimmerman et al (2014). This technique provides a linear signal in response to the amount of cell material analyzed and is able to recover nearly 100% of material from standards (from Qubit HS Assay Kit) that were spiked into the samples.…”

Microzooplankton Stoichiometric Plasticity Inferred from Modeling Mesocosm Experiments in the Peruvian Upwelling Region

“…Initial phytoplankton C, N, P are calculated from (averaged) observed POC, PON, POP concentrations (Franz et al, 2012b(Franz et al, , 2013aHauss et al, 2012), from which we subtract the (averaged) observed dinoflagellate, ciliate, and bacterial biomasses multiplied with assumed zooplankton and bacterial N:C and P:C ratios, Q Table 1. We apply the same N:C and P:C ratios to bacteria (Chrzanowski and Grover, 2008;Pahlow et al, 2008;Zimmerman et al, 2014), which are only used for the calculation of the initial phytoplankton C, N, P in this study. Thus, our initial phytoplankton PON and POP concentrations vary slightly between the different simulations of the same mesocosms, FIGURE 1 | Experimental set-up of the PU1 and PU2 experiments during the M77/3 cruise.…”

Phosphate supply explains variation in nucleic acid allocation but not C : P stoichiometry in the western North Atlantic

“…Marine plankton have taxon-specific limitations on biomass stoichiometry and can have different stoichiometric composition under the same environmental conditions (Grob et al, 2013;Quigg et al, 2003Quigg et al, , 2011Zimmerman et al, 2013). Consequently, community composition affects community stoichiometry, and may contribute to significant differences between oceanic regions Weber and Deutsch, 2010).…”

“…Seawater RNA and DNA concentrations were determined using high-sensitivity, macromolecule-specific Quant-iT fluorophores (Molecular Probes, Inc., Eugene, OR, USA) following a crude lysis as previously described (Zimmerman et al, 2013). Briefly, nucleic acids and proteins were released from filters by mechanical lysis (MP FastPrep-24 bead beater, MP Biomedicals, Solon, OH, USA) in a solution of Tris buffer (5 mM) and RNA preservative (saturated ammonium sulfate solution).…”