Biochemical and physiological responses of Selenastrum gracile (Chlorophyceae) acclimated to different phosphorus concentrations

Autor(es)

Rocha, Giseli Swerts ^{[1, 2]} ; Parrish, Christopher Charles ^[3] ; Lombardi, Ana Teresa ^[4] ; Gama Melao, Maria da Graca ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos UFSCar, CCBS, Dept Hidrobiol, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] WasserCluster Biol Stn Lunz, Dr Carl Kupelwieser Promenade 5, A-3293 Lunz Am See - Austria

^[3] Mem Univ Newfoundland, Dept Ocean Sci, St John, NF A1C 5S7 - Canada

^[4] Univ Fed Sao Carlos UFSCar, CCBS, Dept Bot, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF APPLIED PHYCOLOGY; v. 30, n. 4, p. 2167-2177, AUG 2018.
• Citações Web of Science: 2

Resumo

Algae are able to adjust their metabolism according to their environment, maximizing growth rate and production of biomolecules under adverse conditions such as pulses of excess of a contaminant or limitation of a nutrient. In order to evaluate the effects of phosphorus (P) availability on the biochemical composition of the freshwater microalga Selenastrum gracile, we acclimated the microalgae to different phosphorus concentrations. After acclimation, exponentially growing cells were inoculated and after 120 h, samples were processed for the determination of carbohydrate, lipid, fatty acid, chlorophyll, cell density, growth rate, and dry weight. Cell density, growth rate, and dry weight decreased with less P, while chlorophyll a, carbohydrates, lipids, and fatty acids per cell increased under P limitation. According to our lipid class and fatty acid results, algae alter their metabolism and membrane configuration to avoid more structural or metabolic damage under limitation, especially at 23 mu mol P L-1. The most sensitive parameters under P limitation were chlorophyll a, lipids, and poly- and monounsaturated fatty acids. The changes in fatty acids contributed to the fluorescence and photosynthesis changes under P limitation, and they occurred before changes were detected in other parameters, such as growth rate. Furthermore, we suggest that prior acclimation to different P affected microalgal physiology and metabolism. (AU)

• Processo FAPESP: 08/02078-9 - Estudos ecofisiológicos e de processos produtivos do Anostraca dulcícola Dendrocephalus brasiliensis Pesta 1921 e suas implicações nas comunidades zooplanctônica e nectônica
• Beneficiário: Maria da Graça Gama Melão
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 09/15511-5 - Análise comparativa da composição bioquímica e do valor nutricional de Dendrocephalus brasiliensis, Daphnia laevis e Artemia salina alimentadas com algas cultivadas sob diferentes condições ambientais.
• Beneficiário: Giseli Swerts Rocha
• Modalidade de apoio: Bolsas no Brasil - Doutorado