Nitrogen source uptake and associated pH changes influence growth and biomass composition in microalgae isolated from a polluted river

Registro completo

Título

Nitrogen source uptake and associated pH changes influence growth and biomass composition in microalgae isolated from a polluted river

Autor(es)

Passucci, Victoria; Areco, María del Mar; Ferraro, Gisela; Curutchet, Gustavo Andres

Afiliación(es) del/de los autor(es)

Passucci, Victoria. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina
Areco, María del Mar. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina
Ferraro, Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Curutchet, Gustavo Andres. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina

Resumen

Microalgae exhibit diverse responses to various nitrogen forms in natural environments, affecting growth rates, biomass yields, composition, by-product production, and nutrient utilization efficiency, which vary among species and strains. In the present study, the growth of two microalgae species was investigated with different nitrogen sources to study their effect on these parameters. In particular, the evolution of several parameters associated with microalgal cultures was examined in relation to the nitrogen source and the pH of the culture medium. Furthermore, simple alternative techniques for estimating biomass growth in microalgal cultures based on nitrogen consumption and/or acid/base titrations are proposed. CI (Parachlorella kessleri) and DIII (Desmodesmus communis) were isolated from the Reconquista River, a polluted watercourse in Buenos Aires, Argentina. CI showed higher productivity, faster biomass growth, and increased extracellular polymeric substances (EPS) production, which promoted cell agglomeration, when cultured in culture medium with NO3- as the nitrogen source, compared to cultures with NH4+ as the nitrogen source. On the other hand, DIII grew only when cultured in medium with NO3-, reaching a maximum growth rate comparable to that of CI in culture medium with NO3-. Growth inhibition in cultures containing NH4+ was attributed to pH decrease associated with NH4+ uptake rather than NH4+ effects. Both species exhibited an increase in the C/N ratio. Under N starvation DIII accumulates N-free substances like lipids and starch in both culture conditions, at controlled pH (≈7). In contrast, the results for CI showed a more pronounced increase in the C/N ratio when cultured in medium containing NO3-, which was attributed to the formation of EPS. These variations in the composition of the microalgae biomass and the occurrence of cellular agglomeration throughout a culture suggest that different biomass estimation techniques may not be directly comparable across different phases of a culture. In this sense, in the present work it was demonstrated that for certain conditions, it is possible to accurately estimate growth from the consumption of nitrogen, and from the variation in the concentration of OH- and/or H+ of the culture medium.

Año de publicación

2024

Idioma

inglés

Formato (Tipo MIME)

application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

Clasificación temática de acuerdo a la FORD

Ciencias biológicas

Condiciones de uso

Disponible en acceso abierto bajo licencia Creative Commons https://creativecommons.org/licenses/by-nc-sa/2.5/ar/

Repositorio digital

CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas

Identificador de proyecto

Consejo Nacional de Investigaciones Científicas y Técnicas/PIP 11220170100770CO

Identificador de proyecto

Ministerio de Ciencia. Tecnología e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica/PIP 11220170100770CO