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Growing algae in a photobioreactor

Algae do not only have to be cultivated in nature. This can also be done in a photobioreactor. Light is used for photosynthesis. In addition, CO2 and nutrients are needed for photosynthesis.

In a fully automated photobioreactors, specific conditions can be regulated for the algae. Think, for example, of the optimal temperature, pH value, CO2 supply and biomass concentration in relation to the available light, the nutrient supply and more. These controlled conditions may differ for the different algae species and must therefore be fine-tuned.

Compared to an open (pond) system, a photobioreactor has a low risk of contamination and virtually no CO2 loss.

A photobioreactor generates a higher biomass concentration, faster growth and a completely clean culture of algae. This can be Lgem for you. We give a few advantages of growing algae in a photobioreactor.


Optimal biomass concentration

At an optimal biomass concentration, all available light is absorbed by the biomass. A too dense algae culture causes a larger dark zone and this leads to loss of productivity due to respiration.

On the other hand, too low a biomass concentration leads to loss of photons, especially during periods of high light intensity. The optimal biomass concentration of Tetraselmis suecica grown in a pilot scale tubular photobioreactor using natural sunlight was 0.7 g/L with the highest mean net productivity and yield on light of 0.35 ± 0.03 g/L/d, respectively. and 1.19 ± 0.15 g/mol.


Temperature regulation at night

Results for nighttime cooling in the photobioreactor show that cooling at night does not lead to a reduction in respiration at night and thus an increase in net productivity.

The net volumetric productivity and biochemical composition were only influenced by the daily light amount. More light resulted in cells with a higher carbohydrate content and a lower protein content. During daylight, the carbohydrate content increased, which were then used for protein synthesis at night.

The fatty acid content remained constant throughout the day, except for the EPA content. The EPA content decreased during daylight and increased at night. This reflects the function of EPA as a structural fatty acid present in the polar phospholipid membranes. Furthermore, the carbohydrate loss during the night was linearly related to the specific growth rate and therefore to the light conditions during daylight. Although cooling at night does not increase productivity or affect biochemical composition, energy can be saved by turning off temperature regulation at night.



Algae can do a lot for our health. They have high levels of vitamins, minerals, proteins and other important substances for our body.

Because of this emerging trend, growing algae is more important than ever.

Growing algae can be done better, in an easy and affordable way. Lgem designs and produces reliable and innovative systems for growing algae and we control all the biochemical processes involved. It is important to us that our systems are low labour-intensive, energy efficient and scalable.