Extremophile Research & Biobank CCCRYO
Fraunhofer Institute for Biomedical Engineering
Snow algae are responsible for the phenomenon of green and red snow and as extremophiles they form the bioresource for our research group.
© Fraunhofer IBMT.
The Extremophile Research & Biobank CCCYRO group studies adaptation strategies and the potential to use cryophilic freshwater microalgae, the so-called snow algae, for the human being. The basis for this work is set by the extensive and, regarding its diversity, unique algal culture collection CCCryo. The topics cover three areas:
1. Basic research: Starting with the collection of algal samples during expeditions to polar and high alpine regions of our earth, successively single strains are isolated and characterised with regard to their taxonomy, phylogeny and culture demands. With special attention to their adaptation strategies the Extremophile Research group analyzes the isolates on RNA-, protein- as well as on primary and secondary metabolite level.
2. Applied research: Subsequently the algal strains are studied with regard to industrially interesting metabolites. Antioxidants such as carotenoids, vitamins or polyunsaturated fatty acids (PUFA), and other special substances such as natural freeze protectants are good examples for this. On a laboratory scale their induction and production process is optimized.
3. Photobioreactor design (PBR): For a mass production on an industrial scale the Up-scaling process is optimized and especially adapted photobioreactors are developed. Special attention is paid to a sterile production to provide innovative products suitable for the cosmetics and pharmaceutical sector as well as the food and feed trade.
By this comprehensive approach the Extremophile Research & Biobank CCCRYO group is able to provide research results from the bioresource to the raw product, all from one source. Independently from the above approach the algal strains are available via our CCCryo website for public as well as for private research organizations.
CCCryo - Culture Collection of Cryophilic Algae
- Part of the live strain collection of cryophilic microalgae at the IBMT.
© Fraunhofer IBMT.
Cryophilic (non-obligatory) and psychrophilic (obligatory cold-loving) algae are the main focus of the CCCryo. The majority of algae originally were sampled during expeditions of the IBMT to the Arctic (Spitsbergen) and Antarctic (King-George-Island). Additionally, strains originating from other polar and alpine regions of our earth such as the European Alps and the High Tatra Mountains, the New Zealand Alps, the Rocky Mountains, Greenland, Northern Canada and Alaska are cultivated. Apart from the snow algae also permafrost algae and different mesophilic and some thermophilic algae are in culture. Recent accessions from our latest expedition extend the live collection with eubacteria, cyanobacteria, fungi, and mosses from cold environments. Currently more than 380 strains are held as live cultures at +2 °C, +15 °C und +30 °C and also cryopreserved in Potsdam-Golm and the Fraunhofer BioArchive at the IBMT branch in Sulzbach/Saar.
The online database of the CCCryo as well as ordering information are accessible here. Strains are available for public and private research organizations. A print catalogue may also be downloaded here.
Carotenoids, Antioxidants & Fatty Acids
- Carotenoid spectrum of different algal strains from the CCCryo.
© Fraunhofer IBMT.
Snow and permafrost algae are typical producers of secondary carotenoids and other antioxidants such as alpha-tocopherol (vitamin E). This way they react to stress due to low nutrients and high light and UV-radiation in their natural environment. Especially the latter two result in the formation of free radicals in the algal cells, for which antioxidants are good scavengers. The various algal strains of the CCCryo show a high diversity in their carotenoid spectrum.
The typical mass production process for these metabolites is split into two phases. During the first, a high algal biomass is achieved under optimal nutrient and light conditions. The second production process is induced with appropriate stressors, redirecting the algal metabolism towards the synthesis of secondary carotenoids and lipids in which the former are stored.
Depending on the algal species varying proportions of the following carotenoids or antioxidants can be found:
- alpha- und beta-Carotene
Thereof industry so far is especially interested in Lutein, Astaxanthin and alpha-Tocopherol (Vitamin E) for the dietary supplement and feed sector as well as the cosmetics trade.
Ice Structuring Proteins (ISP) as Freeze Protectants
- Ice structuring proteins (ISP) inhibit the uncontrolled growth of ice crystals.
© Fraunhofer IBMT.
In their natural environment snow algae are continuously exposed to the danger of freezing. This can lead to mechanical disruption of the cell membrane or severe osmotic stress and desiccation. To oppose this many snow algae produce resting stages, others accumulate intracellular metabolites such as sugars or sugar alcohols to depress the freezing point of their cytoplasm or in order to stabilise the cell structure. Only some specialized snow algae produce ice structuring proteins (ISP, formerly also called antifreeze proteins (AFP)), which they excrete to their close environment in order to actively influence ice crystal formation.
ISP are very resistant proteins that irreversibly bind to ice surfaces and actively modify their growth pattern. Instead of uncontrolled large ice faces rather fine crystals are formed due to the interaction of the ISP with the lattice structure of the frozen water. Furthermore the recrystallization of the ice over time is inhibited. Such natural freeze controllers may find application in the medical sector as alternative freeze protectants for cells and tissues or as components for the hypothermal perfusion of transplant tissues. Their use in different fields of food industry is also possible.
Photobioreactor Design & Algal Mass Culture
- Linked-Column photobioreactor (PBR) for mass culture.
© Fraunhofer IBMT.
Phototrophic organisms like microalgae or cyanobacteria are a resource for novel bioactive metabolites of cosmetical or pharmaceutical interest. To yield high quality products adjustable photobioreactor systems are needed to cultivate those microorganisms under sterile and controlled conditions.
The Linked-Column system developed at the Fraunhofer IBMT prevents typical problems of algal cultivation like fouling and cell sedimentation with an optimized design and an effective airlift system that prevents cell damaging shear stress. Mechanical pump or stirrer devices are unnecessary. Sterilization can be performed in-situ by heat or chemicals. Due to the design, the illumination intensity and source (LED or fluorescence tubes) can be adapted to the type of organism and growth phase. This novel Linked-Column photobioreactor system facilitates the mass culture of a broad range of phototrophic microorganisms. As working volumes 10 L and 24 L PBR are available, which can be adapted to desired volumes by addition or removal of single modules.
The systems consist of borosilicate glass components in accordance with GMP guidelines and the directive 97/23/EG. Each reactor holds a CE-certification for pressure vessels. An external temperature control as well as the incorporation of sensors (e.g. for pH and O2) is possible.