Elemental stoichiometry of Fungi and Bacteria strains from grassland leaf litter

• Published in: Soil biology & biochemistry 2014-09, Vol.76, p.278-285
• Main Authors: Mouginot, Céline, Kawamura, Rika, Matulich, Kristin L., Berlemont, Renaud, Allison, Steven D., Amend, Anthony S., Martiny, Adam C.
• Format: Article
• Language: English
• Subjects: Actinobacteria; Agronomy. Soil science and plant productions; Ascomycota; Biochemistry and biology; Biological and medical sciences; C:N:P ratios; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; Growth rate hypothesis; Nutrient stoichiometry; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Proteobacteria; Redfield; Resource allocation; Soil science
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2014.05.011

In most terrestrial environments, our knowledge of the elemental composition and stoichiometry of microorganisms stems from indirect whole community analyses. In contrast, we have little direct knowledge of the elemental composition of specific microorganisms and the variation between and within Fungi and Bacteria. To address this issue, we 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. The C:P and C:N but not N:P ratios were significantly higher in Fungi than in Bacteria. Extensive strain variation in elemental composition was partly linked to phylogeny and growth rate. Across all strains, the geometric mean C:N:P was 88:15:1. This overall ratio was significantly higher than reported for other leaf litter and terrestrial whole communities but closer to the canonical Redfield ratio characterizing marine microorganisms. This result warrants further investigation into the discrepancy between whole community and isolated strain elemental ratios. •The C:N:P ratio in litter Fungi and Bacteria is 88:15:1.•The C:P and C:N but not N:P ratios were higher in Fungi than in Bacteria.•There is extensive variation in the elemental ratios of individual strains.•There is a gap between mean ratios of strains and whole communities.