Evaluation of various techniques for microalgal biomass quantification.
Biomass concentration is one of the most important parameters in the biotechnology processes. Its measurement relies on the physical, chemical or biological properties of the cells. Several techniques were applied in this work to measure the cell concentration of four microalgae: Botryococcussp., Botryococcusbraunii, Chlorella vulgaris, and Ettlia sp. The experiments were performed using samples taken from a chemostat for each strain to provide microalgal cell suspensions in a stable physiological state and concentration. The dry cell weight (DCW) was used as the reference method for the evaluation of other methods. The two commercial sensors used to determine optical density and dielectric permittivity showed a broad effective measurement range up to more than 20gl(-1). A Red-Green-Blue model analysis of microalgal digital images in combination with Fourier equation significantly extended the measurements range up to 6gl(-1). Cell count using a flow cytometer showed a broad range of linearity to DCW in washed samples, but other counting methods using hemocytometer and microscopic automated count were limited. Finally, the oxygen production rate, representing the photosynthetic activity, showed a linear regression with DCW at cell concentrations lower than 1gl(-1).
School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
Mohammad H
MH
Sarrafzadeh
Bioenergy and Biochemical Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea.
Hyun-Joon
HJ
La
Bioenergy and Biochemical Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea.
Seong-Hyun
SH
Seo
School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
Hashem
H
Asgharnejad
Bioenergy and Biochemical Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea. Electronic address: heemock@kribb.re.kr.
Hee-Mock
HM
Oh
D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D003116:Color; D058086:Microalgae / Q000254:growth & development*; D010100:Oxygen / Q000378:metabolism
D010100:Oxygen
Biofuels; Dielectric permittivity; Near infrared optical density; Oxygen production rate; RGB color model