INVESTIGADORES
ZABALOY Maria Celina
congresos y reuniones científicas
Título:
Physiological characterization of microbial communities from agricultural and pristine soils in Argentina
Autor/es:
ZABALOY, MARÍA CELINA; GOMEZ, ELENA V; GARLAND, JAY L.
Lugar:
Mar del Plata
Reunión:
Congreso; XIX Congreso Latinoamericano y XXIII Congreso Argentino de la Ciencia del Suelo; 2012
Institución organizadora:
Asociación Argentina de la Ciencia del Suelo
Resumen:
We used a microplate platform with an oxygen-sensitive fluorophore for community-level physiological profiling (O2 CLPP) of 22 soil samples collected in agricultural and forest sites. The goal of this work was to assess the O2 CLPP to examine the relatedness among soils and the link between respiration and soil C, as well as to examine N limitations in these soils. This new method reduces selective enrichment bias by detecting substrate-induced respiration in soils at low amendment levels and even allows for assessment of basal soil respiration, improving the ecological relevance of the assay over other CLPP approaches. The difference in O2 consumption by soils with and without N addition (Ndiff) is generally indicative of microbial available N, but variability in the relationship may arise, particularly when comparing different soil types. In this work, we showed that the O2 CLPP approach discriminated among different land uses and C contents with a minimum selection of C sources in the assay. The respiratory response to most C-only sources was inversely related to the C content of soils, i.e. substrate induced respiration was higher in soils with higher C limitation. Results indicated substrate-specific variation in N-limitation, suggesting differential sensitivity of various functional pathways or groups of microorganisms to N-limitation. In addition, decreased respiration with N amendment was observed in some microbial communities, so the response appeared also soil-dependent.