title: Relationship between starch and lipid accumulation induced by nutrient depletion and replenishment in the microalga Parachlorella kessleri.
abstract: Photosynthetic carbon partitioning into starch and neutral lipids, as well as the influence of nutrient depletion and replenishment on growth, pigments and storage compounds, were studied in the microalga, Parachlorella kessleri. Starch was utilized as a primary carbon and energy storage compound, but nutrient depletion drove the microalgae to channel fixed carbon into lipids as secondary storage compounds. Nutrient depletion inhibited both cellular division and growth and caused degradation of chlorophyll. Starch content decreased from an initial value of 25, to around 10% of dry weight (DW), while storage lipids increased from almost 0 to about 29% of DW. After transfer of cells into replenished mineral medium, growth, reproductive processes and chlorophyll content recovered within 2 days, while the content of both starch and lipids decreased markedly to 3 or less % of DW; this suggested that they were being used as a source of energy and carbon.
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Bruno
authors.initials: B
authors.lastname: Fernandes
authors.forename: José
authors.initials: J
authors.lastname: Teixeira
authors.forename: Giuliano
authors.initials: G
authors.lastname: Dragone
authors.forename: António A
authors.initials: AA
authors.lastname: Vicente
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kawano
authors.forename: Kateřina
authors.initials: K
authors.lastname: Bišová
authors.forename: Pavel
authors.initials: P
authors.lastname: Přibyl
authors.forename: Vilém
authors.initials: V
authors.lastname: Zachleder
authors.forename: Milada
authors.initials: M
authors.lastname: Vítová
mesh_terms: D018533:Biomass; D002452:Cell Count; D002734:Chlorophyll / Q000378:metabolism; D000460:Chlorophyta / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D050356:Lipid Metabolism; D058086:Microalgae / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D009584:Nitrogen / Q000172:deficiency*; D010758:Phosphorus / Q000172:deficiency*; D058433:Photobioreactors / Q000382:microbiology; D013213:Starch / Q000378:metabolism*
chemical_list: D003470:Culture Media; D002734:Chlorophyll; D010758:Phosphorus; D013213:Starch; D009584:Nitrogen
keywords: Lipids; Nutrient depletion; Nutrient replenishment; Parachlorella kessleri; Starch