Journal of Applied Phycology

, Volume 8, Issue 6, pp 529–534

Growth yield determination in a chemostat culture of the marine microalgaIsochrysis galbana

  • E. Molina Grima
  • F. García Camacho
  • J. A. Sánchez Pérez
  • F. G. Acién Fernández
  • J. M. Fernández Sevilla
Article

DOI: 10.1007/BF02186332

Cite this article as:
Molina Grima, E., García Camacho, F., Sánchez Pérez, J.A. et al. J Appl Phycol (1996) 8: 529. doi:10.1007/BF02186332

Abstract

The growth yield of the PUFA-producing marine microalgaIsochrysis galbana ALII-4 grown in a light limited chemostat, was measured under a wide variety of conditions of incident irradiance (IO) and dilution rates (D). The experiments were conducted under laboratory conditions at 20 °C under continuous light. D ranged from 0.0024 to 0.0410 h−1 at three intensities of Io (820, 1620 and 3270 µmol photon m−2 s−1) close to those found in outdoor cultures. A maximum efficiency Ψmax = 0.616 g mol photon−1 was obtained at IO = 820 µmol photon m−2 s−1 and D = 0.030 h−1 and the maximum capacity of the biomass to metabolize the light harvested was found to be 13.1 µmol photon g−1 s−1. Above this value, a significant drop in the system efficiency was observed. A new approach based in the averaged irradiance is used to assess the photon flux absorbed by the biomass.

Key words

Quantum yield average irradiance light absorption photobioreactor photosynthetic efficiency 

Abbreviations

Cb

Biomass concentration (g m−3 or mg l−1)

D

Dilution rate (h−1)

F

Photon flux (µmol photon s−1)

Fab

Photon flux absorbed by the biomass unit (µmol photon g−1 s−1)

Fvol

Photon flux absorbed in the volume unit (µmol photon m−3 s−1)

Ia

Absorbed light energy (Lee et al. notation (1987)

iav

Average irradiance inside a culture bulk (µmol photon m−2 s−1)

IO

Incident irradiance (µmol photon m−2 s−1)

Ka

Extinction coefficient (g m−2)

Pb

Biomass productivity (g m−3 h−1)

Qb

Biomass combustion enthalpy (kJ g−1)

qo

Energetic content of an equivalent of electrons (113 kJ (eq.e)−1)

V

Volume (m−3)

Ψ

Bioenergetic growth yield (%)

Ψ′

Bioenergetic coefficient from Lee et al. (1987) recalculated with Eqn.[1] (%)

γb

Biomass reduction grade (eq.e eq.C−1)

σb

Carbon content of biomass (mass fraction)

ΨE

Quantum growth yield (g µmol photon−1)

ΨkJ

Energetic growth yield (g kJ−1)

µ

Specific growth rate (h−1)

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • E. Molina Grima
    • 1
  • F. García Camacho
    • 1
  • J. A. Sánchez Pérez
    • 1
  • F. G. Acién Fernández
    • 1
  • J. M. Fernández Sevilla
    • 1
  1. 1.Departamento de Ingeniería Química, Facultad de Ciencias ExperimentalesUniversidad de AlmeríaSpain