Combined nitrogen limitation and cadmium stress stimulate total carbohydrates, lipids, protein and amino acid accumulation in Chlorella vulgaris (Trebouxiophyceae)

Author(s)

Chia, Mathias Ahii ^[1] ; Lombardi, Ana Teresa ^[1] ; Gama Melao, Maria da Graca ^[2] ; Parrish, Christopher C. ^[3]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Bot, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Hydrobiol, BR-13565905 Sao Carlos, SP - Brazil

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

• Document type: Journal article
• Source: AQUATIC TOXICOLOGY; v. 160, p. 87-95, MAR 2015.
• Web of Science Citations: 31

Abstract

Metals have interactive effects on the uptake and metabolism of nutrients in microalgae. However, the effect of trace metal toxicity on amino acid composition of Chlorella vulgaris as a function of varying nitrogen concentrations is not known. In this research, C vulgaris was used to investigate the influence of cadmium (10(-7) and 2.0 x 10(-8) mol L-1 Cd) under varying nitrogen (2.9 x 10(-6), 1.1 x 10(-5) and 1.1 x 10(-3) mol L-1 N) concentrations on its growth rate, biomass and biochemical composition. Total carbohydrates, total proteins, total lipids, as well as individual amino acid proportions were determined. The combination of Cd stress and N limitation significantly inhibited growth rate and cell density of C vulgaris. However, increasing N limitation and Cd stress stimulated higher dry weight and chlorophyll a production per cell. Furthermore, biomolecules like total proteins, carbohydrates and lipids increased with increasing N limitation and Cd stress. Ketogenic and glucogenic amino acids were accumulated under the stress conditions investigated in the present study. Amino acids involved in metal chelation like proline, histidine and glutamine were significantly increased after exposure to combined Cd stress and N limitation. We conclude that N limitation and Cd stress affects the physiology of C. vulgaris by not only decreasing its growth but also stimulating biomolecule production. (C) 2015 Elsevier B.V. All rights reserved. (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: 08/03487-0 - Microalgae culture in photobioreactor as a tool for atmospheric CO2 mitigation
• Grantee: Ana Teresa Lombardi
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Research Partnership for Technological Innovation (PITE)