Enhancing sustainability through microalgae cultivation in urban wastewater for biostimulant production and nutrient recovery.

Autor: Álvarez-González A; GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain., Greque de Morais E; GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain., Planas-Carbonell A; GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain., Uggetti E; GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain. Electronic address: enrica.uggetti@upc.edu.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2023 Dec 15; Vol. 904, pp. 166878. Date of Electronic Publication: 2023 Sep 09.
DOI: 10.1016/j.scitotenv.2023.166878
Abstrakt: Microalgae can produce biostimulants in form of phytohormones, which are compounds that, even if applied in low concentrations, can have stimulant effects on plants growth and can enhance their quality and their resistance to stress. Considering that microalgal biomass can grow recovering nutrients from wastewater, this circular approach allows to use residues for the production of high added value compounds (such as phytohormones) at low cost. The interest on biostimulants production from microalgae have recently raised. Scientists are focused on the direct application of these cellular extracts on plants, while the number of studies on the identification of bioactive molecules, such as phytohormones, is very scarce. Two cyanobacteria strains (Synechocystis sp. (SY) and Phormidium sp. (PH)) and a chlorophyte (Scenedesmus sp. (SC)) were cultured in laboratory-scale PBRs with a working volume of 2.5 L in secondary urban wastewater varying N:P ratio in the cultures to obtain the highest productivity. The variation of N:P ratio affects microalgae growth, and SY and PH presented higher productivities (73 and 48 mg L -1  d, respectively) under higher N:P ratio (> 22:1). Microalgal biomass was freeze-dried and phytohormones content was measured with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The three microalgae showed similar phytohormones profiles, being the auxin (indole-3-acetic acid, IAA) the most abundant (72 ng g -1 DW in SY). Proteins were major macronutrient for all strains, reaching 48 % DW in PH culture. To optimize the biostimulants production, a balance between the production of such compounds, biomass productivity and nutrients removal should be taken into consideration. In this sense, SC was the most promising strain, showing the highest N and P removal rates (73 % and 59 %, respectively) while producing phytohormones.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE