title: Control of protozoa contamination and lipid accumulation in Neochloris oleoabundans culture: Effects of pH and dissolved inorganic carbon.
abstract: Combined effects of pH (i.e., 7.5, 8.5, and 9.5) and bicarbonate (i.e., 0, 80 and 160mM NaHCO3) on lipid accumulation and on biological contaminant viability in a protozoa-contaminated culture of the freshwater microalga Neochloris oleoabundans were studied. Cultures grown in the media containing 160mM NaHCO3 at pH 9.5 obtained the highest biomass concentration (DCWmax=1.32g/L), lipid content (LC=327mg/g), which corresponded to a lipid productivity of 56mg/(L·d), and the culture was protozoa free one day after inoculation. Other cultures, 160mM NaHCO3 at pH 8.5 (DCWmax=1.32g/L, LC=223mg/g), and 80mM NaHCO3 at pH 9.5 (DCWmax=1.25g/L, LC=264mg/g) could delay protozoan growth, but not inhibit it completely. These results suggest 160mM NaHCO3 or slightly above at pH levels of 8.5-9.5 may be used in outdoor cultivation processes of freshwater N. oleoabundans to control protozoa contamination while maintain a high lipid content.
authors: Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
authors: Licheng
authors: L
authors: Peng
authors: Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, ON K1N 6N5, Canada. Electronic address: Christopher.Lan@uottawa.ca.
authors: Christopher Q
authors: CQ
authors: Lan
authors: Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
authors: Zisheng
authors: Z
authors: Zhang
authors: Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
authors: Cody
authors: C
authors: Sarch
authors: Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
authors: Matt
authors: M
authors: Laporte
mesh_terms: D018533:Biomass; D002244:Carbon / Q000737:chemistry*; D000460:Chlorophyta / Q000254:growth & development* / Q000378:metabolism; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D058086:Microalgae; D017693:Sodium Bicarbonate
chemical_list: D003470:Culture Media; D008055:Lipids; D002244:Carbon; D017693:Sodium Bicarbonate
keywords: DIC; Lipid; Neochloris oleoabundans; Protozoa contamination; pH