Microalgae production with aquaculture cycle water

PBR 3000 photobioreactor, IGV Biotech

15. 07.2013 /Nuthetal, Germany – Within the funding initiative “Sustainable Aquaculture” from the Deutsche Bundesstiftung Umwelt DBU, IGV Biotech has successfully started the operation of a photobioreactor (PBR) with 3000 liters cultivation volume.

Within this photobioreactor, microalgae assimilate nutrients, which are dissolved in aquaculture cycle water. They produce a biomass with high fatty acid content under use of solar energy. The produced microalgae will be processed into fish feed. Their efficiency as replacement or supplement of currently employed fish oil or fish meal will be examined in feed trials.

Funding initiative “Sustainable Aquaculture”

Global demand of food industry for fish based products increases rapidly and challenges producing countries. The waste water of fish hatcheries, which are often placed in sensitive river deltas or riverside or mangrove forests, is in many times discharged into the environment without sufficient clarification. The accompanying nutrients can pollute ground water and living spaces and can cause uncontrolled algae blooms including negative impacts on the whole marine ecosystem. In addition, the industrial production of fish feed is often based on commercial fishing, which puts marine fish resources under strong pressure. The DBU-funded initiative supports alternative approaches on this issue. Being led by IGV GmbH, or its microalgae specialized department IGV Biotech respectively, an aquaculture hatchery and a feed production company had joined to build a threesome network.

Microalgae and aquaculture

Microalgae and fishes live in the same natural environment. Microalgae can grow on the nutrients from the fishes’ excrements, while using sunlight and CO2 for photosynthesis. They are the first element of the aquatic food chain and followed by microscope sized animals or crustaceans, which then are again live feed for bigger fishes. Hence, microalgae have the potential for closing a sustainable and resource-efficient cycle within aquaculture production processes.

Within the current project the waste water of the fish hatchery is fed into a photobioreactor for the production of microalgae while examining the conversion efficiency. A microalgae specie with a valuable natural fatty acid content has been selected out of the numerous count of different organisms and is now cultivated at the hatchery’s company ground. The produced and harvested microalgae will be processed into special fish feed while replacing fish oil and fish meal in changing amounts. Finally, the new fish feed is tested with juvenile fishes.

Photobioreactor PBR 3000 G

IGV Biotech contributed the photobioreactor PBR 3000 G to the project. This skid-mounted mobile photobioreactor contains three parallel glass tube modules with only thin layers of culture suspension, wherein the microalgae are supplied with natural sunlight for photosynthesis. The PBR has a total operational volume of 3000 liters and supplies the algae suspension with nutrients from the fish hatchery waste water and CO2. The CO2 is absorbed by the microalgae and is processed to fats and all other organic compounds while exhausting pure oxygen into the environment. After successful growth, the microalgae will be harvested and refilled with the according amount of fish cycle water.

Video of transport and setting up the PBR 3000 G photobioreactor

Source: IGV Biotech