Influence of Microcystis sp. and freshwater algae on pH: Changes in their growth associated with sediment

Carolina Acuña-Alonso; Olalla Lorenzo; Xana Álvarez; Ángeles Cancela; Enrique Valero; Ángel Sánchez

doi:10.1016/j.envpol.2020.114435

Influence of Microcystis sp. and freshwater algae on pH: Changes in their growth associated with sediment

Environ Pollut. 2020 Aug;263(Pt B):114435. doi: 10.1016/j.envpol.2020.114435. Epub 2020 Apr 2.

Authors

Carolina Acuña-Alonso¹, Olalla Lorenzo², Xana Álvarez³, Ángeles Cancela⁴, Enrique Valero⁵, Ángel Sánchez⁶

Affiliations

¹ Engineering Department of Natural Resources and Environment, School of Forestry Engineering, University of Vigo, Campus A Xunqueira s/n., 36005, Pontevedra, Spain. Electronic address: carolina.alonso@uvigo.es.
² School of Forestry Engineering, Campus A Xunqueira s/n, University of Vigo, 36005, Pontevedra, Spain. Electronic address: olallalorenzomiguez@gmail.com.
³ Engineering Department of Natural Resources and Environment, School of Forestry Engineering, University of Vigo, Campus A Xunqueira s/n., 36005, Pontevedra, Spain. Electronic address: xaalvarez@uvigo.es.
⁴ Chemical Engineering Department, School of Forestry Engineering, University of Vigo, Campus CampusAXunqueira s/n., 36005, Pontevedra, Spain. Electronic address: chiqui@uvigo.es.
⁵ Engineering Department of Natural Resources and Environment, School of Forestry Engineering, University of Vigo, Campus A Xunqueira s/n., 36005, Pontevedra, Spain. Electronic address: evalero@uvigo.es.
⁶ Chemical Engineering Department, Industrial Engineering College, University of Vigo, Campus Lagoas-Marcosende s/n, 36310, Vigo, Pontevedra, Spain. Electronic address: asanchez@uvigo.es.

PMID: 32283394
DOI: 10.1016/j.envpol.2020.114435

Abstract

Samples from two reservoirs with eutrophication problems, located in Pontevedra and Ourense (Northwestern Spain), were cultured, along with a third crop from a reservoir with no problems detected in Ourense (Northwestern Spain). The samples were grown under the same conditions (with an average temperature of 21 ± 2 °C, and a 3000 lux light intensity) in triplicate, and their growth, absorbance and pH were studied. High correlation values were obtained for pH and cellular growth (R² ≥ 95%). The water from Salas showed the greatest microalgal growth (0.15 × 10⁶ cells/ml to 31.70 × 10⁶ cells/ml of Microcystis sp. for the last day of culturing) and the greatest increase in pH (5.72-9.02). In all the cultures studied here, the main species that reproduced was Microcystis sp., which can produce neurotoxins and hepatotoxins. In addition, water samples were cultured with sediments of their own reservoir and with others to observe their evolution. The sediments studied in this case were rich in biotites, which can lead phosphate to be a limiting factor for phytoplankton due to the formation and sedimentation of insoluble salts of ferric phosphate. In crops grown with sediments from the Salas reservoir, actinobacteria developed which can inhibit microalgal growth. The study of the growth of cyanobacteria and possible methods of inhibiting them directly concerns the quality of water and its ecosystems, avoiding pollution and impact on ecosystems.

Keywords: Cyanobacteria; Eutrophication; Microalgae; Microcystis aeruginosa; Water quality; pH variations.

MeSH terms

Ecosystem
Eutrophication
Fresh Water
Hydrogen-Ion Concentration
Microcystis*
Spain