title: A microscale approach for simple and rapid monitoring of cell growth and lipid accumulation in Neochloris oleoabundans.
abstract: Due to the increasing environmental problems caused by the use of fossil fuels, microalgae have been spotlighted as renewable resources to produce biomass and biofuels. Therefore, the investigation of the optimum culture conditions of microalgae in a short time is one of the important factors for improving growth and lipid productivity. Herein, we developed a PDMS-based high-throughput screening system to rapidly and easily determine the optimum conditions for high-density culture and lipid accumulation of Neochloris oleoabundans. Using the microreactor, we were able to find the optimal culture conditions of N. oleoabundans within 5 days by rapid and parallel monitoring growth and lipid induction under diverse conditions of light intensity, pH, CO2 and nitrate concentration. We found that the maximum growth rate (µ max = 2.13 day(-1)) achieved in the microreactor was 1.58-fold higher than that in a flask (µ max = 1.34 day(-1)) at the light intensity of 40 µmol photons m(-2) s(-1), 5 % CO2 (v/v), pH 7.5 and 7 mM nitrate. In addition, we observed that the accumulation of lipid in the microreactor was 1.5-fold faster than in a flask under optimum culture condition. These results show that the microscale approach has the great potential for improving growth and lipid productivity by high-throughput screening of diverse optimum conditions.
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul, 136-713, South Korea.
authors.forename: Ho Seok
authors.initials: HS
authors.lastname: Kwak
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul, 136-713, South Korea.
authors.forename: Jaoon Young Hwan
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul, 136-713, South Korea. simsj@korea.ac.kr.|Green School, Korea University, Seoul, 136-713, South Korea. simsj@korea.ac.kr.
authors.forename: Sang Jun
authors.initials: SJ
authors.lastname: Sim
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis; D049109:Cell Proliferation / Q000502:physiology*; D000460:Chlorophyta / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects; D003470:Culture Media / Q000032:analysis / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006863:Hydrogen-Ion Concentration; D008027:Light; D050356:Lipid Metabolism / Q000187:drug effects / Q000502:physiology*; D008055:Lipids / Q000032:analysis*; D058433:Photobioreactors / Q000382:microbiology*; D011874:Radiometry / Q000295:instrumentation; D046888:Tissue Array Analysis / Q000295:instrumentation*
chemical_list: D003470:Culture Media; D008055:Lipids; D002245:Carbon Dioxide
keywords: Microalgal culture; Microscale approach; Neochloris oleoabundans; Nile red; PDMS-based microreactor