pH and CO2 effects on Coelastrella (Scotiellopsis) rubescens growth and metabolism
Autor: | R. A. Sidorov, N. V. Dantsyuk, E. G. Sakhon, Alexei Solovchenko, Konstantin Chekanov, I. N. Chubchikova, E. S. Chelebieva, Elena Lobakova, Olga B. Chivkunova, G. S. Minyuk, I. V. Drobetskaya |
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Rok vydání: | 2016 |
Předmět: |
0106 biological sciences
0301 basic medicine chemistry.chemical_classification Physiological condition Fatty acid Chlorophyceae Plant Science Photosynthetic pigment Biology biology.organism_classification 01 natural sciences 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology chemistry Dry weight Astaxanthin Botany Food science Carotenoid 010606 plant biology & botany Polyunsaturated fatty acid |
Zdroj: | Russian Journal of Plant Physiology. 63:566-574 |
ISSN: | 1608-3407 1021-4437 |
DOI: | 10.1134/s1021443716040105 |
Popis: | We studied effects of рН and СО2 enrichment on the physiological condition and biochemical composition of a carotenogenic microalga Coelastrella (Scotiellopsis Vinatzer) rubescens Kaufnerova et Elias (Scenedesmaceae, Sphaeropleales, Chlorophyceae), a promising source of natural astaxanthin. The microalga was grown at a constant pH (5, 6, 7 or 8) maintained by direct СО2 injection. The air-sparged culture served as the control. Cell division rate and size, dry biomass productivity, the rates of nitrogen and phosphorus uptake as well as photosynthetic pigment and total lipid content and fatty acid composition were followed. С. rubescens possessed a narrow-range рН tolerance (the optimum рН 6–7). Under these conditions, the highest values of the maximum (1.0–1.1 1/day) and average (0.3–0.35 1/day) specific growth rate, chlorophyll а (4.8–4.9%) and total carotenoid dry weight percentages (1.7–1.8%) were recorded. Cell lipid fatty acid unsaturation index (1.851) and polyunsaturated fatty acid percentage (36–39%) and С18:3 ω3/С18:1 ω9 ratio (3.8–4.5) were also the highest under these conditions. A decline of рН to 5 brought about severe stress manifesting itself as a cell division cessation, photosynthetic apparatus reduction, two-fold increase in cell volume, accumulation of dry weight and lipids and a considerable decline in fatty acid unsaturation. Cultivation of С. rubescens without СО2 enrichment resulted in a rapid alkalization of the medium to рН 9.5–10.5 impairing the physiological condition of the cells. Reasons of the deteriorative effects of suboptimal pH values on the physiological condition of C. rubescens are discussed. |
Databáze: | OpenAIRE |
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