Abstract

Background: Continuous culture is a method with significant benefits that is underused in the area of microalgae. Despite this, with the spread of these cultures into many different areas, such as biofuel production, pigment production for the food and pharmaceutics industries, effluent treatment, biosorption of heavy metals, it is necessary and imperative to make advancements in the technology in terms of knowledge and use. Therefore, it is necessary to identify its fundamental basis and to fully understand its operation in order to be able to successfully maximise important parameters such as biomass or metabolite productivity.

Methods: This article presents the fundamental concepts and applies them clearly and simply in continuous culture photobioreactors operated as light-limited chemostats, using a Scenedesmus obliquus culture.

Results: This article presents the basis and applications of a simple light-limited chemostat method, which is the most commonly-used type of operation for achieving high levels of biomass productivity. The usefulness of operation curves: microalgae concentration(X) - dilution rate (D) and volumetric productivity of cells (Qx) - D and how to build them are also presented, along with the operational and environmental design parameters that affect them.

Conclusion: The construction of operation curves for the microalga in question must be carried out in a laboratory with day-night cycles of temperature and irradiance to obtain critical D values and the optimal D at which to successfully operate the outdoor culture.

Keywords: Continuous culture, microalgae, Scenedesmus obliquus, light limited chemostat, operation curves, photobioreactors.

Graphical Abstract