title: Combined nitrogen limitation and hydrogen peroxide treatment enhances neutral lipid accumulation in the marine diatom Phaeodactylum tricornutum.
abstract: Exogenous application of dilute hydrogen peroxide (H2O2) increases neutral lipid production in Phaeodactylum tricornutum. Exposing early stationary phase cultures of P. tricornutum to 0.25-2mM H2O2 increases the amount of neutral lipids per biomass (mg/mg) by >100% at 24h post H2O2 treatment as determined upon lipid extraction and analysis using a neutral lipid assay. H2O2 treatment increased the total levels of neutral lipids harvested up to 50%, from 64mg/L to 96mg/L, demonstrating its possible effectiveness as a pre-harvest strategy to enhance the biofuel feedstock potential of P. tricornutum. The effects of H2O2 on biomass are concentration dependent; increasing concentrations of H2O2 reduce the levels of isolated biomass. Analysis of combined stressors demonstrates that H2O2 treatment exhibits synergistic effects to enhance neutral lipid production under nitrogen-depleted, but not phosphorus-depleted conditions, suggesting that the effects of hydrogen peroxide on lipid production are influenced by environmental nitrogen levels.
authors.affiliation: Department of Chemistry, One Shields Avenue, University of California, Davis, CA 95616, United States; Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California, Davis, CA 95616, United States.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Burch
authors.affiliation: Department of Chemistry, One Shields Avenue, University of California, Davis, CA 95616, United States; Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California, Davis, CA 95616, United States. Electronic address: akfranz@ucdavis.edu.
authors.forename: Annaliese K
authors.initials: AK
authors.lastname: Franz
mesh_terms: D056804:Biofuels; D018533:Biomass; D017377:Diatoms / Q000187:drug effects / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects*; D009584:Nitrogen / Q000172:deficiency*
chemical_list: D056804:Biofuels; D006861:Hydrogen Peroxide; D009584:Nitrogen
keywords: Hydrogen peroxide; Lipid accumulation; Nitrogen limitation; Oxidative stress; Phaeodactylum tricornutum