Different ecophysiological and structural strategies of toxic and non-toxic Microcystis aeruginosa (cyanobacteria) strains assessed under culture conditions

Autor(es)

Jacinavicius, Fernanda R. ^{[1, 2]} ; Pacheco, Ana Beatriz F. ^[3] ; Chow, Fungyi ^[4] ; Verissimo da Costa, Giovani C. ^[5] ; Kalume, Dario Eluan ^[6] ; Rigonato, Janaina ^[7] ; Schmidt, Eder C. ^[8] ; Sant'Anna, Celia L. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Bot, Nucleus Phycol, Ave Miguel Stefano 3687, Caiza Postal 4005, BR-01051 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Fac Pharmaceut Sci, Ave Prof Lineu Prestes 580, BR-05508900 Sao Paulo, SP - Brazil

^[3] Univ Fed Rio de Janeiro, Biophys Inst, Ave Carlos Chagas Filho 373, Cidade Univ, BR-21941170 Rio De Janeiro, RJ - Brazil

^[4] Univ Sao Paulo, Inst Biosci, Rua Matao 303, BR-05508900 Sao Paulo, SP - Brazil

^[5] UFF, Rua Dr Silvio Henrique Braune 22, BR-28625650 Nova Friburgo, RJ - Brazil

^[6] Fundacao Oswaldo Cruz FIOCRUZ, IOC, Lab Interdisciplinar Pesquisas Med, Ave Brasil 4365, BR-21040360 Rio De Janeiro, RJ - Brazil

^[7] Inst Biociencias Letras & Ciencias Exatas, Dept Zool & Bot, Rua Cristovao Colombo 2265, Sao Jose Do Rio Preto, SP - Brazil

^[8] Univ Fed Santa Catarina, Dept Cell Biol Embryol & Genet, Rua Engn Agron Andrei Cristian Ferreira S-N, BR-88049900 Florianopolis, SC - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS; v. 41, AUG 2019.
• Citações Web of Science: 1

Resumo

Microcystis aeruginosa causes severe problems in freshwater environments worldwide due to its capacity to form blooms and produce toxins. Natural populations contain a mixture of strains that vary in morphology, genotype and microcystin production. Beyond its toxic effect in animals, the possible role of microcystin in the metabolism of the producing cell is also a topic of interest. Recent studies pointed to a protective role against cellular oxidative stress. Since natural populations include microcystin producing and non-producing strains, the latter must rely on other ecophysiological traits to thrive. Here, we compared a toxic and a non-toxic strain of M. aeruginosa displaying different morphotypes and growth behaviors, aiming to explore the role of microcystin in an integrated way to the primary metabolism. The toxic strain formed large floating colonies (150-1850 mu m) with densely aggregated cells, numerous gas vesicles and lipid inclusions and a typical irregular thylakoid arrangement. The non-toxic strain remained submerged, formed small colonies (< 100 mu m) with a dense mucilage covering few sparse cells with rare gas vesicles and various types of thylakoids. It showed a higher abundance of carboxysomes, cyanophycin and polyphosphate granules and also greater amounts of pigments than the toxic strain. The antioxidant potential was higher for the toxic strain and it presented a higher expression of proteins related to photosynthesis, protein folding and cellular redox homeostasis. These traits of the toxic strain were compatible with growth under higher irradiance and microcystin can be a key factor to this adaptation. Growing submerged, the non-toxic strain showed preference for a lower light intensity and invested in intracellular reserves. This study illustrates different adaptive strategies of M. aeruginosa morphotypes that can be valuable in nature, enabling this species to widely exploit freshwater ecosystems. (AU)

• Processo FAPESP: 11/50267-8 - Aspectos morfológicos, fisiológicos e bioquímicos e suas relações com produção de microcistinas em cepas de Microcystis aeruginosa (Cyanobacteria)
• Beneficiário: Fernanda Rios Jacinavicius
• Modalidade de apoio: Bolsas no Brasil - Doutorado