soil microbial communities 60:7:1 leaf litter microbial communities 16:4:1 marine bacteria 77:17:1 C:N:P
||Céline Mouginot et al., Elemental stoichiometry of Fungi and Bacteria strains from grassland leaf litter, Soil Biology and Biochemistry Volume 76, September 2014, Pages 278–285 link p.278 left column & p.282 right column 2nd paragraph
||Cleveland, C.C., Liptzin, D., 2007. C: N: P stoichiometry in soil: is there a “Redfield ratio” for the microbial biomass? Biogeochemistry 85, 235-252 link AND Van Meeteren, M.J.M., Tietema, A., van Loon, E.E., Verstraten, J.M., 2008. Microbial dynamics and litter decomposition under a changed climate in a Dutch heathland. Applied Soil Ecology 38, 119-127 link AND Zimmerman, A.E., Allison, S.D., Martiny, A.C., 2014. Phylogenetic constraints on elemental stoichiometry and resource allocation in heterotrophic marine bacteria. Environmental Microbiology 16, 1398-1410. doi: 10.1111/1462-2920.12329. PubMed ID24237481
||Abstract: "In most terrestrial environments, [investigators'] knowledge of the elemental composition and stoichiometry of microorganisms stems from indirect whole community analyses. In contrast, [they] have little direct knowledge of the elemental composition of specific microorganisms and the variation between and within Fungi and Bacteria. To address this issue, [they] isolated and identified the elemental content of 87 strains of Fungi and Bacteria isolated from grassland leaf litter. The isolated strains were affiliated with a broad range of diversity including Ascomycota and Basidiomycota for Fungi, and Proteobacteria, Bacteroidetes, and Actinobacteria for Bacteria." Primary source Zimmerman et al abstract: "Using a 'common-garden' experimental design, [investigators] detected significant interspecific variation in stoichiometry, macromolecule allocation and growth rate among 13 strains of marine Proteobacteria."
||P.278 left column: "The ratios of carbon (C), nitrogen (N), and phosphorus (P) in the environment and within organisms link the biogeochemical cycles of these important elements (Sterner and Elser, 2002). Despite the importance of stoichiometric ratios, less is known about their magnitude and variation in microorganisms in terrestrial environments. In the most extensive comparison of different soil microbial communities, [primary source Cleveland and Liptzin (2007)] found an average microbial C:N:P molar ratios of 60:7:1. On leaf litter, microbial communities also show low C:N:P ratios of 16:4:1 (primary source Van Meeteren et al., 2008). These ratios are starkly lower than the averages observed in marine environments as described by the Redfield ratio (106:16:1). Such values suggest that terrestrial microorganisms generally are depleted in C and N - or enriched in P - compared to marine microorganisms." p.282 right column 2nd paragraph: "Finally, [investigators] compared the elemental stoichiometry of the leaf litter Bacteria to that of a suite of marine Bacteria (C:N:P= 77:17:1) previously analyzed (primary source Zimmerman et al., 2014). Despite large differences in growth conditions between the two sets of strains, the average ratios did not differ (two-sample t-test, p > 0.05)." Primary source Cleveland & Liptzin abstract: "[Investigators'] analysis indicates that, similar to marine phytoplankton, element concentrations of individual phylogenetic groups within the soil microbial community may vary, but on average, atomic C:N:P ratios in both the soil (186:13:1) and the soil microbial biomass (60:7:1) are well-constrained at the global scale."