Cyanobacteria-based consortium for agro-industrial wastewater treatment with simultaneous biodiesel production in attached growth systems

In this work, an attached growth system was employed using a mixed microbial culture dominated by the photosynthetic cyanobacteria Leptolyngbya and Limnothrix in diverse heterotrophic consortia as revealed by Next-Generation Sequencing. Kinetic experiments with different initial pollutant concentrations (C, N and P) were carried out in the attached growth system to determine the ability of the established culture to remove organic matter content (dissolved chemical oxygen demand, d-COD), nitrogen and phosphorus from dairy, winery and mixed effluent (winery-raisin) wastewaters. The produced microbial lipids contained high percentages of saturated and mono-unsaturated fatty acids in all substrates tested implying that the produced biomass can potentially be used for biodiesel production. The results indicate that the proposed attached growth photobioreactor system can be considered an effective wastewater treatment system that simultaneously produces promising biodiesel feedstock in the form of microbial biomass.