Algae research: aquatic treasures are the future

Microalga in photobioreactor screening modules (Image: FAU)

Microalga in photobioreactor screening modules
(Image: FAU)

FAU researchers want to make large-scale algae production economically viable

About a million euros from German Federal Ministry for Education and Research budgets have been placed at the disposal of Prof. Dr. Rainer Buchholz and his colleague Prof. Dr. Antonio Delgado to realise a vision: together with E.ON Hanse, the two researchers want to cultivate single-celled algae on an industrial scale to harvest the resources that algae have to offer. These run the gamut from antiviral and antibacterial substances for use in medicine, colourants, and organic raw materials to fatty acids for liquid biofuels.

The remaining algae matter could be used to run biogas plants. Best of all, the researchers are taking the German climate into account so that the production will not have to be moved to a more southerly country later on. The project is not just run from Erlangen, however, but also from Busan, Korea, where FAU has its branch campus and trains young chemical and biological engineers. E.ON is also contributing research hours and the use of a large outdoor facility.

Science and industry captivated by microalgae

They have elegant-sounding names such as Dunaliella, Chlorella or Spirulina. Microscopic images of microalgae are often very beautiful. The reason they are so interesting as a resource and raw material is that their photosynthesis transforms inexpensive sunlight into power. They also contain a surprising number of sought-after, high-quality substances that humans can use in many different industrial applications. Furthermore, they produce important raw materials that can serve as alternatives to the finite resources that are currently used.

The potential of single-celled algae has fired the imagination of biotechnologists for several years, for instance as a renewable resource for liquid fuels. Efficient procedures to render industrial use of algae economically viable have been lacking so far, however. At FAU’s Department of Bioprocess Engineering, Prof. Dr. Buchholz and his team plan to develop first applications and examine their potential. The project’s goal is to achieve a high degree of efficiency in the processing of algae biomass, similar to how oil refinery has been perfected. At the same time, the researchers are hoping to identify new species of algae that are especially suited to these purposes.

The first step is to cultivate as many different algae species as possible and examine them with regard to their usability. ‘We screen all kinds of different algae, from marine to freshwater,’ says Buchholz. The marine alga Dunaliella salina, for instance, contains large amounts of beta-carotene and can be cultivated in high salinity. Other types contain fatty acids that are important for the energy sector. The bioprocess engineers are looking at algae that are cultivated outdoors, as their production can be rather cheap.

Analysis across borders brings benefits

They also want to examine whether the carbon dioxide from exhaust fumes from power plants can be used as a source of carbon – for example at the plant run by E.ON Hanse in Hamburg. In the laboratory at his department in Erlangen, however, Buchholz (who also leads the Algenbiotechnologie group at DECHEMA Gesellschaft für Chemische Technik und Biotechnologie e.V.) has built a closed cultivation plant for microalgae which can produce any quantity to fill anything from a glass flask to a 120-litre reactor. Designed for sterile conditions, this plant is where the researchers are most likely to extract agents for medical uses.

Buchholz and his colleagues are not stopping at research in Germany, though: ‘Microalgae biorefinery’ is a co-operation project between FAU and its Korean branch, the FAU Campus Busan. Chemical and biological engineers there will contribute to the screening process, cultivate algae, and perhaps even identify species that have not yet been discovered. During their first evaluations, the researchers have already ‘discovered several specimens that we consider to be very relevant,’ says Buchholz. ‘And we hope to find further interesting candidates.’

The charm of Korea: unlike Germany, it has a long coastline – and thus plenty of space for plants in which to cultivate algae. Furthermore, the Korean climate is very interesting for drawing comparisons: Busan is on the same latitude as Naples. Buchholz now wants to find out whether the difference in sunlight intensity and duration of daylight in the two locations has an effect on algal growth.

Once suitable species have been identified, the goal is to get the most out of the algae – all its components should be used in an optimal way to satisfy different industrial needs. The project will develop the biorefinery processin close collaboration with FAU’s fluid mechanics researchers: using fluid mechanics calculations, Prof. Delgado and his team aim to optimise the reactors to ensure that all protozoa get enough light even in dense culture solutions from prolific algae.

Such culture solutions quickly become so opaque that light cannot penetrate them to any significant depth. Most algae in the solution can therefore hardly get any energy unless appropriate measures are taken. At the same time, the process specialists are trying to combine suitable procedures in order to create a biorefinery process that exploits the algae as efficiently as possible and to make the overall process as economic as possible. ‘We hope to be able to present the first results within the next three years, so that we can demonstrate how promising algae are for the future,’ Buchholz explains.

Further information:

Prof. Dr. Rainer Buchholz
Phone: +49 (0)9131 85 23003


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