Nitrogen flux into metabolites and microcystins changes in response to different nitrogen sources in Microcystis aeruginosa NIES-843.

Autor: Krausfeldt LE; Department of Microbiology, University of Tennessee, Knoxville, TN, USA., Farmer AT; Department of Chemistry, University of Tennessee, Knoxville, TN, USA., Castro HF; Department of Chemistry, University of Tennessee, Knoxville, TN, USA., Boyer GL; Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, NY, USA., Campagna SR; Department of Chemistry, University of Tennessee, Knoxville, TN, USA., Wilhelm SW; Department of Microbiology, University of Tennessee, Knoxville, TN, USA.
Jazyk: angličtina
Zdroj: Environmental microbiology [Environ Microbiol] 2020 Jun; Vol. 22 (6), pp. 2419-2431. Date of Electronic Publication: 2020 May 05.
DOI: 10.1111/1462-2920.15032
Abstrakt: The over-enrichment of nitrogen (N) in the environment has contributed to severe and recurring harmful cyanobacterial blooms, especially by the non-N 2 -fixing Microcystis spp. N chemical speciation influences cyanobacterial growth, persistence and the production of the hepatotoxin microcystin, but the physiological mechanisms to explain these observations remain unresolved. Stable-labelled isotopes and metabolomics were employed to address the influence of nitrate, ammonium, and urea on cellular physiology and production of microcystins in Microcystis aeruginosa NIES-843. Global metabolic changes were driven by both N speciation and diel cycling. Tracing 15 N-labelled nitrate, ammonium, and urea through the metabolome revealed N uptake, regardless of species, was linked to C assimilation. The production of amino acids, like arginine, and other N-rich compounds corresponded with greater turnover of microcystins in cells grown on urea compared to nitrate and ammonium. However, 15 N was incorporated into microcystins from all N sources. The differences in N flux were attributed to the energetic efficiency of growth on each N source. While N in general plays an important role in sustaining biomass, these data show that N-speciation induces physiological changes that culminate in differences in global metabolism, cellular microcystin quotas and congener composition.
(© 2020 Society for Applied Microbiology and John Wiley & Sons Ltd.)
Databáze: MEDLINE
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