RT info:eu-repo/semantics/article
T1 Digestate dilution shapes carbohydrate and pigment production during microalgal and cyanobacterial-based biogas upgrading
A1 Ciani, Matilde
A1 Vargas Estrada, Laura Gabriela
A1 Adessi, Alessandra
A1 Muñoz Torre, Raúl
K1 Biogas upgrading
K1 Metabolites
K1 Microalgae
K1 Nutrient recovery
K1 Wastewater dilution
K1 3308 Ingeniería y Tecnología del Medio Ambiente
AB Microalgae and cyanobacteria offer a promising platform for integrating sustainable technologies aligned withcircular and green economy goals. However, current studies often focus on a limited number of genera andoverlook how centrate dilution influences metabolite production. This study investigates the potential of thefreshwater microalga Parachlorella hussii N9 and the marine cyanobacterium Cyanothece sp. CE4 for photobio-logical biogas upgrading coupled with nutrient recovery from centrate, assessing the impact of centrate dilutionon carbohydrate and pigment content. By varying centrate concentration (5–50 %) in tap or seawater, thisresearch explores how the biogas-to-centrate ratio can be adjusted for biomass production, TN and CO2 abate-ment, and to target specific metabolites, advancing circular bioeconomy strategies. The microalga exhibitedfaster growth than the cyanobacterium, achieving the stationary phase in three days, and higher cellular andsoluble carbohydrate productivity (up to 237 and 75 mg L 1d 1, respectively). CO₂ abatement (almost completein all treatments) reached ~513 ± 28 mg L 1 of culture, while nitrogen removal considering initial centrateconcentration ranged between 32 and 250 mg N L 1, but 100 % TN removal was exhibited only with the lowercentrate concentrations (5–10 %). These lower concentrations also induced the highest carbohydrate content inbiomass (41–44 % dw). In contrast, pigment content increased with higher centrate concentrations: the micro-alga reached 3.6 % dw of chlorophyll at 50 % centrate, while the cyanobacterium produced up to 0.6 % dw of C-phycocyanin; both strains showed similar carotenoid content (0.4–0.5 % dw). This study highlights the potentialof adjusting centrate dilution to target microalgal metabolism for integrated CO₂ capture, nutrient recovery, andbioproduct generation.
PB Elsevier
SN 2211-9264
YR 2025
FD 2025
LK https://uvadoc.uva.es/handle/10324/78799
UL https://uvadoc.uva.es/handle/10324/78799
LA eng
NO Algal Research, 2025, vol. 91, p. 104290
NO Producción Científica
DS UVaDOC
RD 13-nov-2025