In vitro toxicity of isolated strains and cyanobacterial bloom biomasses over Paramecium caudatum (ciliophora): Lessons from a non-metazoan model organism

Author(s)

Vilas Boas, Layne Amaral ^[1] ; Xavier Senra, Marcus Vinicius ^{[1, 2]} ; Fernandes, Kelly ^[3] ; da Anunciacao Gomes, Andreia Maria ^[4] ; Pedroso Dias, Roberto Junio ^[2] ; Pinto, Ernani ^{[5, 3, 6]} ; Fonseca, Ana Lucia ^[1]

Affiliation

^[1] Univ Fed Itajuba, Inst Recursos Nat, BR-37500903 Itajuba, MG - Brazil

^[2] Univ Fed Juiz de Fora, Inst Ciencias Biol, Lab Protozool, Programa Posgrad Comportamento & Biol Anim, Campus Univ, BR-36036900 Juiz De Fora, MG - Brazil

^[3] Univ Sao Paulo, Fac Pharmaceut Sci, BR-05508000 Sao Paulo - Brazil

^[4] Inst Fed Educ Ciencias & Tecnol Rio de Janeiro, BR-24310000 Niteroi, RJ - Brazil

^[5] Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13416000 Piracicaba, SP - Brazil

^[6] Univ Sao Paulo, Food Res Ctr FoRC CEPID, BR-05508000 Sao Paulo - Brazil

• Document type: Journal article
• Source: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY; v. 202, OCT 1 2020.
• Web of Science Citations: 0

Abstract

Cyanobacteria have been considered a major global threat because of their widespread ability to proliferate and contaminate inland and marine waters with toxic metabolites. For this reason, to avoid risks to humans and environmental health, regulatory legislation and guidelines have been established based on extensive toxicological data. However, most of what is known in this field come from works on microcystin (MC) variants, which effects were almost exclusively tested in metazoan models. In this work, we used acute end-point toxicological assays and high-resolution hybrid quadrupole time-of-flight mass spectrometer coupled with electrospray ionization source (ESI-Q-TOF-MS) analyses to evaluate the deleterious impact of aqueous extracts prepared from cultures of cyanobacteria and environmental bloom biomasses over a non-metazoan model organism, the cosmopolitan fresh/brackish water unicellular microeukaryote, Paramecium caudatum (Ciliophora). Our data suggest that all extracts produced time-dependent effects on P. caudatum survival, irrespective of their metabolite profile; and that this ciliate is more sensitive to extracts containing microginins than to extracts with only MCs, stressing that more toxicological investigations should be performed on the environmental impact of neglected cyanotoxins. Further, our data provide evidence that P. caudatum may be more sensitive to cyanotoxins than vertebrates, indicating that guidelines values, set on metazoans are likely to be inaccurate to protect organisms from basal food web positions. Thus, we highly recommend the widespread use of microeukaryotes, such as ciliates in environmental risk assessment frameworks for the establishment of more reliable cyanotoxin monitoring guideline values. (AU)

• FAPESP's process: 14/50420-9 - Secondary metabolites from aquatic microrganisms and their impact on seafood and freshwater fish aquaculture
• Grantee: Ernani Pinto Junior
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/01563-2 - Investigating the secondary metabolism of Brasilonema (Cyanobacteria: Scytonemataceae)
• Grantee: Danillo Oliveira de Alvarenga
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor