Microcystin and saxitoxins on green microalgae and cyanobacteria under controlled conditions

• Grant number: 11/50840-0
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2011
• End date: September 30, 2013
• Field of knowledge: Engineering - Sanitary Engineering - Water Resources
• Principal Investigator: Maria Do Carmo Bittencourt de Oliveira
• Grantee: Maria Do Carmo Bittencourt de Oliveira
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• City of the host institution: Piracicaba

Abstract

Allelophathic effects are biochemical interactions, from stimuli as from inhibition, among different primary producers. The hypothesis by which cyanotoxins have allelophatic action was not yet confirmed since results so far obtained are controversial, once the tested toxin concentrations are not usual in the aquatic environment. This study aims at the evaluation of allelophathic effects of saxitoxins (SX) and microcystins (MC) in the growth of green algae ((Monoraphidium convolutum (Corda) Komarková-Legnerová (CMEA/UFF0201 and Scenedesmus acuminatas (UFSCar036) as well as in the toxic and non toxic cyanobacteria (Microcystis wesenbergii (Komárek) Komárek, M. pannifomis Komárek and M. aeruginosa (Kützing) Kützing). Three different experiments will be carried out: (a) green algae versus extract bruto of toxic and non-toxic cyanobcteria; (b) green algae versus cyanobacteria, and cyanobacteria versus extract brutos of green algae. The experiments will be performed under controlled conditions for temperature, photoperiod and light luminosity ((24± 1°C, 14:10h-light:dark and 50μmol.m-2.s-1). The effects allelophathic will be tested from the growing follow up of green microalgae and cyanobacteria during 15 days, by means of cell number counting, and also microcystin concentrations, as dictated by the case. The hypothesis to be tested is the low concentration of microcystin does not lead to allelophathic effects on the growing of green and cyanobacteria. The results will also subsidize discussion on interactions between phytoplankton species of cyanobacteria and green microalgae, envisaging going deeper into the understanding of these relations in the structure of the phytoplankton community. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BITTENCOURT-OLIVEIRA, MARIA DO CARMO; CHIA, MATHIAS AHII; BEZERRA DE OLIVEIRA, HELTON SORIANO; CORDEIRO ARAUJO, MICHELINE KEZIA; REIS MOLICA, RENATO JOSE; SANTOS DIAS, CARLOS TADEU. Allelopathic interactions between microcystin-producing and non-microcystin-producing cyanobacteria and green microalgae: implications for microcystins production. JOURNAL OF APPLIED PHYCOLOGY, v. 27, n. 1, p. 275-284, FEB 2015. (13/11306-3, 11/50840-0)

BITTENCOURT-OLIVEIRA, MARIA DO CARMO; CHIA, MATHIAS AHII; CAMARGO-SANTOS, DANILO; DIAS, CARLOS T. S.. The effect of saxitoxin and non-saxitoxin extracts of Cylindrospermopsis raciborskii (Cyanobacteria) on cyanobacteria and green microalgae. JOURNAL OF APPLIED PHYCOLOGY, v. 28, n. 1, p. 241-250, FEB 2016. (13/11306-3, 11/02957-5, 11/50840-0)