Allelopathic effects of cyanotoxins on the physiological responses of Chlorella vulgaris.

Autor: Albuquerque MVDC; Departamento de Engenharia Sanitária e Ambiental, Universidade Estadual da Paraíba, 58429-500, Campina Grande, Paraíba, Brazil. Electronic address: virginia.albuquerque@yahoo.com.br., Ramos RO; Departamento de Ciências Agrárias, Universidade Estadual da Paraíba, 58429-500, Campina Grande, Paraíba, Brazil., de Paula E Silva MCC; Departamento de Engenharia Sanitária e Ambiental, Universidade Estadual da Paraíba, 58429-500, Campina Grande, Paraíba, Brazil., Rodrigues RMM; Departamento de Engenharia Sanitária e Ambiental, Universidade Estadual da Paraíba, 58429-500, Campina Grande, Paraíba, Brazil., Leite VD; Departamento de Engenharia Sanitária e Ambiental, Universidade Estadual da Paraíba, 58429-500, Campina Grande, Paraíba, Brazil., Lopes WS; Departamento de Engenharia Sanitária e Ambiental, Universidade Estadual da Paraíba, 58429-500, Campina Grande, Paraíba, Brazil.
Jazyk: angličtina
Zdroj: Toxicon : official journal of the International Society on Toxinology [Toxicon] 2024 Sep; Vol. 248, pp. 107847. Date of Electronic Publication: 2024 Jul 16.
DOI: 10.1016/j.toxicon.2024.107847
Abstrakt: Contributing to the assessment of potential physiological changes in microalgae subjected to different concentrations and types of cyanotoxins, this study investigated the inhibitory effects of cyanotoxins on the growth, density, biomass, and ecotoxicity of Chlorella vulgaris. Chlorella vulgaris was exposed to crude extracts of cyanobacteria producing microcystin-LR (MC-LR), saxitoxin (SXT), anatoxin-a (ATX-A), and cylindrospermopsin (CYN) with initial concentrations of 5.0, 2.05, 0.61, and 1.42 μg.L -1 , respectively. The experiments were conducted under controlled conditions, and monitoring of growth and cell inhibition occurred at 24h, 48h, 72h, and 96h. Chlorophyll-a content and ecotoxicity assessment were conducted with samples collected after 96h of exposure to cyanotoxins. The growth assays of Chlorella vulgaris, with results expressed in terms of average growth rates (doublings/day), indicated the following order for cyanotoxins: SXT (2.03) > CYN (1.66) > MC-LR (1.56) > ATX-A (0.18). This assay revealed the prominent inhibitory potential of ATX-A on Chlorella vulgaris growth compared to the other toxins evaluated. Regarding the inhibition of the photosynthetic process, expressed in terms of the percentage inhibition of Chlorophyll-a, the following order for cyanotoxins was obtained: ATX-A (82%) > MC-LR (76%) > STX (46%) > CYN (16%). These results also indicated that among the cyanotoxins, ATX-A was the most detrimental to the photosynthetic process. However, contrary to the observations in the growth study, SXT proved to be more harmful than CYN in terms of Chlorophyll-a inhibition. Finally, the results of the toxicity assay revealed that only ATX-A and MC-LR exerted a chronic influence on Chlorella vulgaris under the investigated conditions.
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.
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Databáze: MEDLINE