Effects of light intensity and temperature on Cylindrospermopsis raciborskii (Cyanobacteria) with straight and coiled trichomes: growth rate and morphology

Autor(es)

Bittencourt-Oliveira, M. C. ^{[1, 2]} ; Buch, B. ^{[1, 2]} ; Hereman, T. C. ^{[1, 2]} ; Arruda-Neto, J. D. T. ^{[3, 4]} ; Moura, A. N. ^[5] ; Zocchi, S. S. ^[6]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, ESALQ, Dept Ciencias Biol, BR-13418900 Piracicaba, SP - Brazil

^[2] Univ Estadual Paulista, UNESP, Area Biol Vegetal, Programa Posgrad Ciencias Biol, BR-13506900 Rio Claro, SP - Brazil

^[3] Univ Sao Paulo, Inst Fis, Lab Acelerador Linear, BR-01498 Sao Paulo - Brazil

^[4] Italy Brazilian Univ Ctr, Sao Paulo - Brazil

^[5] Univ Fed Rural Pernambuco UFRPE, Area Bot, Dept Biol, BR-52171030 Recife, PE - Brazil

^[6] Univ Sao Paulo, ESALQ, Dept Ciencias Exatas, BR-13418900 Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Biology; v. 72, n. 2, p. 343-351, MAY 2012.
• Citações Web of Science: 13

Resumo

Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju (Ordem Nostocales) is one of the most troublesome bloom-forming species in Brazil. Understanding the population dynamics of the different morphotypes of C. raciborskii (straight and coiled) could assist in the prediction of favourable conditions for the proliferation of this potentially toxin-producing species. The aim of the present study was to assess the effects of two different light intensities and temperatures on the growth rate and morphology of the trichomes of the straight and coiled morphotypes. For such, two non-toxin producing strains of C. raciborskii were used - one with a coiled trichome (ITEP31) and another with a straight trichome (ITEP28). The strains were cultured in BG-11 medium in a climatic chamber under controlled conditions. Two light intensities (30 and 90 mu mol.m(-2).s(-1)) were combined at temperatures of 21 and 31 degrees C and the growth rate and morphological changes were analysed. The morphotypes responded differently to the different temperatures and light intensities. Both strains exhibited faster growth velocities when submitted to higher light intensity and temperature. The lower temperature and higher luminosity hampered the development of both strains. Variations in cellular morphology and an absence of akinetes in both strains were related to the lower temperature (21 C). The coiled morphotype demonstrated considerable phenotype plasticity, changing the morphology of trichome throughout its growth curve. Although molecular analysis does not sustain the separation of the morphotypes as distinct species, their different eco-physiological responses should be considered further knowledge of extreme importance for the population control of these potentially toxic organisms. (AU)

• Processo FAPESP: 07/57509-1 - Ecofisiologia de morfotipos reto e espiralado de Cylindrospermopsis raciborskii (Cyanobactéria) em condições controladas
• Beneficiário: Bruna Buch
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 04/00939-6 - Efeito da intensidade luminosa na dinamica populacional de morfotipos reto e espiralado de cylindrospermopsis raciborskii (cyanobacteria) em condicoes controladas.
• Beneficiário: Bruna Buch
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica