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

Author(s)

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

Affiliation

^[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

• Document type: Journal article
• Source: JOURNAL OF APPLIED PHYCOLOGY; v. 30, n. 4, p. 2167-2177, AUG 2018.
• Web of Science Citations: 2

Abstract

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)

• FAPESP's process: 08/02078-9 - Ecophysiological and production studies of the freshwater Anostraca Dendrocephalus brasiliensis Pesta 1921 and its implications on zooplanktonic and nektonic communities
• Grantee: Maria da Graça Gama Melão
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 09/15511-5 - Comparative analysis of biochemical composition and nutritional value of Dendrocephalus brasiliensis, Daphnia laevis and Artemia salina fed with algae growth under different environmental conditions.
• Grantee: Giseli Swerts Rocha
• Support Opportunities: Scholarships in Brazil - Doctorate