Control of the Nitrogen Isotope Composition of the Fungal Biomass: Evidence of Microbial Nitrogen Use Efficiency.

ABSTRACT: Changes in ¹⁵N/¹⁴N in the soil microbial biomass during nitrogen (N) mineralization have been hypothesized to influence ¹⁵N/¹⁴N in soil organic matter among ecosystem sites. However, a direct experimental test of this mechanism has not yet been performed. To evaluate the potential control of microbial N mineralization on the natural N isotope composition, we cultured fungi (Aspergillus oryzae) in five types of media of varying C:N ratios of 5, 10, 30, 50, and 100 for 4 d, and tracked changes in δ¹⁵N in the microbial biomass, NH₄⁺, and dissolved organic N (DON: glycine) over the course of the experiment. High rates of NH₄⁺ excretion from A. oryzae were accompanied by an increase in δ¹⁵

SUBMITTER: Shinoda K 

PROVIDER: S-EPMC6440729 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature