Abstract
Microalgae blooms are natural processes that occur in eutrophic aquatic ecosystems. Microalgae blooms, namely those constituted by cyanobacteria, are undergoing a significant expansion as a result of anthropogenic pollution and climate change. Many of these blooms cause environmental and public health concerns due to the production and accumulation of toxic substances by some cyanobacterial species. Despite the burdens that cyanobacteria may cause in the environment and human health, cyanobacterial biomasses are interesting sources of compounds in biotechnology. Cyanobacteria also have interesting plant growth properties, and their biomass is an excellent soil amendment. In order to promote safe use of this type of material in biotechnology and agriculture, a research work was outlined, which consisted in seeking inexpensive and environmentally sustainable methods of treatment of Microcystis aeruginosa biomass and to reduce the content of the toxin microcystin (MC) in the biomass. Lyophilized or hydrated biomass from laboratory cultures of M. aeruginosa were subjected to treatments by heat (50 °C), ultraviolet radiation, ozone, and solar radiation for periods ranging from 2 to 12 h. The results demonstrate a significant reduction in the amount of MC in the biomass exposed to natural radiation for 12 h, from 0.0042 to 0.0028 mg of MC-LR/mg of dry biomass, equivalent to a reduction of about 33% of the total toxin. Efforts are currently being made to characterize the chemical transformation of the toxin catalyzed by natural radiation. No other treatment allowed us to reduce the amount of toxin present in the biomass, which suggests a strong chemical resistance of MC. This method of treatment of cyanobacterial biomass is quite interesting, and its use on a large scale depends on a confirmation of the preservation of the biotechnological properties of biomass after the applied treatment.
Author Contributions
Conceptualization, L.L., A.C. and V.V.; methodology, L.L., J.A. and A.C.; formal analysis, L.L., J.A. and A.C.; investigation, L.L., J.A. and A.C.; writing—original draft preparation, L.L. and A.C.; writing—review and editing, L.L., A.C., J.A. and V.V.; supervision, A.C. and V.V.; funding acquisition, A.C. and V.V. All authors have read and agreed to the published version of the manuscript.
Funding
This work received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 823860.
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
Not applicable.
Conflicts of Interest
The authors declare no conflict of interest.
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |
© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).