Variation of photoautotrophic fatty acid production from a highly CO2 tolerant alga, Chlorococcum littorale, with inorganic carbon over narrow ranges of pH.
Photoautotrophic fatty acid production of a highly CO2 -tolerant green alga Chlorococcum littorale in the presence of inorganic carbon at 295 K and light intensity of 170 µmol-photon m(-2) s(-1) was investigated. CO2 concentration in the bubbling gas was adjusted by mixing pure gas components of CO2 and N2 to avoid photorespiration and β-oxidation of fatty acids under O2 surrounding conditions. Maximum content of total fatty acid showed pH-dependence after nitrate depletion of the culture media and increased with the corresponding inorganic carbon ratio. Namely, [HCO3 (-) ]/([CO2 ]+n[ CO32-]) ratio in the culture media was found to be a controlling factor for photoautotrophic fatty acid production after the nitrate limitation. At a CO2 concentration of 5% (vol/vol) and a pH of 6.7, the fatty acid content was 47.8 wt % (dry basis) at its maximum that is comparable with land plant seed oils.
Research Center of Supercritical Fluid Technology, Tohoku University, Sendai, 980-8579, Japan.
Masaki
M
Ota
Research Center of Supercritical Fluid Technology, Tohoku University, Sendai, 980-8579, Japan.
Motohiro
M
Takenaka
Research Center of Supercritical Fluid Technology, Tohoku University, Sendai, 980-8579, Japan.
Yoshiyuki
Y
Sato
Research Center of Supercritical Fluid Technology, Tohoku University, Sendai, 980-8579, Japan.
Richard L
RL
Smith
Research Center of Supercritical Fluid Technology, Tohoku University, Sendai, 980-8579, Japan.
Hiroshi
H
Inomata
D056804:Biofuels; D002245:Carbon Dioxide / Q000378:metabolism*; D000460:Chlorophyta / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D058086:Microalgae / Q000378:metabolism*
D056804:Biofuels; D005227:Fatty Acids; D002245:Carbon Dioxide
algal oil; biofuels; biomass; green algae; microalgae