Fungal – assisted microalgae flocculation and simultaneous lignocellulolytic enzyme production in wastewater treatment systems
Year: 2025
Type: article
Abstract: • Fungal-driven flocculation is a chemical-free, scalable algae harvesting method. • Algal-fungal complexes form, aided by fungal enzyme production and hydrolysis. • Algal-fungal interaction is more of a harmful relationship than symbiosis. • Up to 95 % of microalgae were harvested from wastewater in 24 h at reactor scale. • Resulting biomass can be used for cellulolytic enzyme production. The study investigates the application of white rot fungi for reactor–scale microalgae harvesting and explores the mechanisms underlying the algal–fungal interactions and their impact on biomass composition. Enzymatic analysis and microscopy revealed that the formation of algal-fungal complexes and successful harvesting are coupled with fungal cellulose-degrading enzyme production and hydrolytic processes of microalgae cells. Fluorescence intensity decreased by over 80 % in cells stained with Calcofluor-white after interaction with white rot fungi, indicating the reduction in cellulose content in microalgal cells caused by fungal enzymatic activity. These enzymes also caused significant cell damage and more than 50 % decrease in microalgae cell size. The presence of cellulolytic enzymes broadens the potential application of the resulting biomass in various biotechnological applications. Moreover, reactor-scale bioflocculation resulted in over 95 % T. obliquus and almost 85 % C. vulgaris harvesting efficiency from secondary wastewater within less than 24 h, demonstrating the method's scalability and industrial applicability.
Source: Biotechnology Reports
Authors: Anna Civzele, Linda Mezule
Institution: Riga Technical University
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,480
Awards: G2130108454, G8529608112
OpenAlex ID: W4406268360