Anais CBFic - Volume 1 - 2018

Sociedade Brasileira de Ficologia - SBFic

Publicado em 26/11/2018

Volume 1 - 2019

Título do Trabalho

PHYSIOLOGICAL RESPONSES AND BIOFILTER POTENTIAL OF GRACILARIA CAUDATA (GRACILARIALES, RHODOPHYTA) IN VARIATION ON NITROGEN AND PHOSPHORUS AVAILABILITIES

Autores

JôNATAS MARTINEZ CANUTO DE SOUZA, VITOR G. CHIOZZINI, ELISABETE S. BRAGA , NAIR SUMIE YOKOYA

Modalidade

Resumo

Área Temática

1 BIODIVERSIDADE, FILOGENIA E ECOFISIOLOGIA

Data de Publicação

26/11/2018

País da Publicação

Brasil

Idioma da Publicação

Português

Página do Trabalho

http://sbfic.org.br/anais_show/88

ISSN

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Palavras-Chave

Biofiltel, nitrogen, phosphorus, Gracilaria caudata

Resumo

Benthic marine algae can be biofilters by assimilation of nutrients of the medium in their metabolism. Species of Gracilaria Greville are exploited as raw material for the agar production and studies on their development are necessary for the sustainable production of biomass. The present study aims to evaluate the effects of nitrogen and phosphorus availabilities in the metabolism of Gracilaria caudata J.Agardh. Experiments was performed with 50% von Stosch solution without N and P, which were added to the medium as nitrate (in concentrations from 0.0 to 500 μM), and phosphate, in the N:P ratio of 10:1 to 100:1. Each treatment was tested with four replicates (n=4) in the Growth rates, number of primary and secondary branches, pigments (chlorophyll a, phycoerythrin, phycocyanin and allophycocyanin), total soluble proteins, total soluble carbohydrates, photosynthetic parameters (Pmax, yield, Ik and α), and removal efficiency were analysed. Experiments were conducted under temperature of 23±2°C, photoperiod of 14h, salinity 32 psu, and 80±10 µmol photons.m-2.s-1. Data were analysed by one-way ANOVA followed by “a posteriori” test of Student-Newman-Keuls. The growth rates varied from 5.7±0.2% .d-1 in 500.0:50.0 µM N:P ratio, to 2.6±0.2% .d-1 in seawater without added nutrients. The number of primary branches had 9.0±0.0 in 500.0:50.0 µM, N:P ratio. In the secondary branches had 4.0±0.8 in 500.0:50.0 µM N:P ratio. G. caudata cultured with 250.0:25.0 µM N:P ratio, showed the highest concentrations of phycoerythrin (337.5±15.8 mg.g-1 FM) and phycocyanin (84.4±18.6 mg.g-1 FM). Chlorophyll a (41.6±2.1 mg.g-1 FM) in 500.0:50.0 µM N:P ratio. Allophycocyanin concentrations was higher in 250.0:2.5 µM N:P ratio,135.3±9.6 mg.g-1 FM. Proteins was higher (4.6±0.5 mg.g-1 FM) in 125.0:1.25 µM N:P ratio. Ethanol extract carbohydrates was higher (4.2±1.0 mg.g-1 FM ) in 125.0:1.25 µM N:P ratio, in water extract was 15.2±4.0 in VSES/2. The higher values in, Pmax was 5.4±1.2 ETR in 500.0:50.0 µM N:P ratio, Yields ranged was 0.325±0.0 in 250.0:25.0 µM N:P ratio, Ik was 5.4±1.2 in 500.0:50 µM N:P ratio and α was 0.04±0.0 in 125.0:1.25 µM N:P ratio. The removal efficiency of nitrate was better in VSES/2 (98.7±0.0%), phosphate was in 50.0:0.5 µM N:P ratio, 66.8±5.8%. Our results showed that the highest N:P concentration was decreased the growth rate and removal efficiency, but increased the number of primary and secondary branches, concentration of phycoerythrin, phycocyanin, chlorophyll a and proteins. Financial supports: CAPES (AUXPE-CIMAR 1991/2014, Processo no. 23038.001431/2014-75), FAPESP (2017/13295-3)