title: RELEASE OF CARBOHYDRATES AND PROTEINS BY A SUBTROPICAL STRAIN OF RAPHIDIOPSIS BROOKII (CYANOBACTERIA) ABLE TO PRODUCE SAXITOXIN AT THREE NITRATE CONCENTRATIONS(1).
abstract: Raphidiopsis brookii P. J. Hill (cyanobacteria) was isolated from a small subtropical eutrophic pond (Biguá Pond) located in the grounds of Rio Grande University in the extreme south of Brazil, following a toxic bloom of this species. Growth, saxitoxin production, and release of carbohydrates and protein were monitored at three sodium nitrate concentrations (500, 1,000, and 1,500 μM), from inoculation up to the stationary growth phase. Growth was monitored by determining the biovolume, chl content, and trichome count. Growth was better described in terms of biovolume and chl measurements, because trichome fragmentation was observed to increase at the stationary growth phase. Carbohydrates and proteins were released in small amounts during most of the experiment, with a significant increase during the stationary phase. Extracellular polysaccharides were essentially composed of glucose, galactose, N-acetyl-glucosamine, mannose, xylose, rhamnose, arabinose, and fucose. The relative proportions of these units showed no significant variation during growth. Small quantities of extracellular free carbohydrates were also detected, and only fucose was released in significant amounts at the lowest nitrate concentration (500 μM). R. brookii produced both saxitoxin and dc-saxitoxin, the former at four times the rate of the latter. This was the first study demonstrating saxitoxin production and the release of both carbohydrate and protein by R. brookii.
authors.affiliation: Instituto de Oceanografia, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Ciências Biológicas, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Botanica, Secao de Ficologia, Av. Miguel Estefano, 3687, Agua Funda, São Paulo, SP, Brasil, 04301-012Departamento de Botanica, Unversidade Federal de São Carlos, Via Washington Luis, Km 235, São Carlos, SP, Brasil, 13565-905.
authors.forename: João Sarkis
authors.initials: JS
authors.lastname: Yunes
authors.affiliation: Instituto de Oceanografia, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Ciências Biológicas, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Botanica, Secao de Ficologia, Av. Miguel Estefano, 3687, Agua Funda, São Paulo, SP, Brasil, 04301-012Departamento de Botanica, Unversidade Federal de São Carlos, Via Washington Luis, Km 235, São Carlos, SP, Brasil, 13565-905.
authors.forename: Sabrina
authors.initials: S
authors.lastname: De La Rocha
authors.affiliation: Instituto de Oceanografia, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Ciências Biológicas, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Botanica, Secao de Ficologia, Av. Miguel Estefano, 3687, Agua Funda, São Paulo, SP, Brasil, 04301-012Departamento de Botanica, Unversidade Federal de São Carlos, Via Washington Luis, Km 235, São Carlos, SP, Brasil, 13565-905.
authors.forename: Danilo
authors.initials: D
authors.lastname: Giroldo
authors.affiliation: Instituto de Oceanografia, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Ciências Biológicas, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Botanica, Secao de Ficologia, Av. Miguel Estefano, 3687, Agua Funda, São Paulo, SP, Brasil, 04301-012Departamento de Botanica, Unversidade Federal de São Carlos, Via Washington Luis, Km 235, São Carlos, SP, Brasil, 13565-905.
authors.forename: Savenia Bonoto da
authors.initials: SB
authors.lastname: Silveira
authors.affiliation: Instituto de Oceanografia, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Ciências Biológicas, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Botanica, Secao de Ficologia, Av. Miguel Estefano, 3687, Agua Funda, São Paulo, SP, Brasil, 04301-012Departamento de Botanica, Unversidade Federal de São Carlos, Via Washington Luis, Km 235, São Carlos, SP, Brasil, 13565-905.
authors.forename: Rubens
authors.initials: R
authors.lastname: Comin
authors.affiliation: Instituto de Oceanografia, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Ciências Biológicas, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Botanica, Secao de Ficologia, Av. Miguel Estefano, 3687, Agua Funda, São Paulo, SP, Brasil, 04301-012Departamento de Botanica, Unversidade Federal de São Carlos, Via Washington Luis, Km 235, São Carlos, SP, Brasil, 13565-905.
authors.forename: Miriam da Silva
authors.initials: Mda S
authors.lastname: Bicho
authors.affiliation: Instituto de Oceanografia, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Ciências Biológicas, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Botanica, Secao de Ficologia, Av. Miguel Estefano, 3687, Agua Funda, São Paulo, SP, Brasil, 04301-012Departamento de Botanica, Unversidade Federal de São Carlos, Via Washington Luis, Km 235, São Carlos, SP, Brasil, 13565-905.
authors.forename: Silvia Susanne
authors.initials: SS
authors.lastname: Melcher
authors.affiliation: Instituto de Oceanografia, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Ciências Biológicas, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Botanica, Secao de Ficologia, Av. Miguel Estefano, 3687, Agua Funda, São Paulo, SP, Brasil, 04301-012Departamento de Botanica, Unversidade Federal de São Carlos, Via Washington Luis, Km 235, São Carlos, SP, Brasil, 13565-905.
authors.forename: Célia Leite
authors.initials: CL
authors.lastname: Sant'anna
authors.affiliation: Instituto de Oceanografia, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Ciências Biológicas, Universidade Federal de Rio Grande, Av. Italia, Km 8, Rio Grande, RS, Brasil, 96201-900Instituto de Botanica, Secao de Ficologia, Av. Miguel Estefano, 3687, Agua Funda, São Paulo, SP, Brasil, 04301-012Departamento de Botanica, Unversidade Federal de São Carlos, Via Washington Luis, Km 235, São Carlos, SP, Brasil, 13565-905.
authors.forename: Armando Augusto Henriques
authors.initials: AA
authors.lastname: Vieira
keywords: Raphidiopsis; carbohydrate; cyanobacteria; nitrate; polysaccharide; protein; saxitoxin