title: Interaction of Temperature and Photoperiod Increases Growth and Oil Content in the Marine Microalgae Dunaliella viridis.
abstract: Eukaryotic marine microalgae like Dunaliella spp. have great potential as a feedstock for liquid transportation fuels because they grow fast and can accumulate high levels of triacylgycerides with little need for fresh water or land. Their growth rates vary between species and are dependent on environmental conditions. The cell cycle, starch and triacylglycerol accumulation are controlled by the diurnal light:dark cycle. Storage compounds like starch and triacylglycerol accumulate in the light when CO2 fixation rates exceed the need of assimilated carbon and energy for cell maintenance and division during the dark phase. To delineate environmental effects, we analyzed cell division rates, metabolism and transcriptional regulation in Dunaliella viridis in response to changes in light duration and growth temperatures. Its rate of cell division was increased under continuous light conditions, while a shift in temperature from 25 °C to 35 °C did not significantly affect the cell division rate, but increased the triacylglycerol content per cell several-fold under continuous light. The amount of saturated fatty acids in triacylglycerol fraction was more responsive to an increase in temperature than to a change in the light regime. Detailed fatty acid profiles showed that Dunaliella viridis incorporated lauric acid (C12:0) into triacylglycerol after 24 hours under continuous light. Transcriptome analysis identified potential regulators involved in the light and temperature-induced lipid accumulation in Dunaliella viridis.
authors.affiliation: Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Soundarya
authors.initials: S
authors.lastname: Srirangan
authors.affiliation: Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Sauer
authors.affiliation: Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Brian
authors.initials: B
authors.lastname: Howard
authors.affiliation: Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Mia
authors.initials: M
authors.lastname: Dvora
authors.affiliation: Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Jacob
authors.initials: J
authors.lastname: Dums
authors.affiliation: Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Patrick
authors.initials: P
authors.lastname: Backman
authors.affiliation: Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Heike
authors.initials: H
authors.lastname: Sederoff
mesh_terms: D008386:Marine Biology; D058086:Microalgae / Q000254:growth & development* / Q000378:metabolism; D008969:Molecular Sequence Data; D009821:Oils / Q000378:metabolism*; D017440:Photoperiod; D013696:Temperature
chemical_list: D009821:Oils