Microalgae

Next to bacteria and fungi, microalgae play a central role in our research group GMBU “Functional Coatings” for the biofunctionalization of material surfaces and biotechnological applications. Unlike macroalgae (e.g., seaweed), microalgae are microscopic and typically unicellular, existing in a wide variety of forms. Like plants, algae and cyanobacteria are capable of converting sunlight into chemical energy through photosynthesis. This unique ability allows them to build biomass from carbon dioxide and water, playing a crucial role in oxygen production. Compared to higher plants, algae can utilize sunlight more efficiently, making them particularly attractive for applications in various industries, including pharmaceuticals, food, animal feed, and cosmetics.

Here are some aspects of how microalgae can be applied:

• Biofuels: Microalgae can serve as a raw material for the production of biofuels. By extracting oil from microalgae, biodiesel or biokerosene can be produced.
• Nutrition: Microalgae are rich in nutrients and proteins. Certain species of microalgae are used as dietary supplements or in food production to increase the protein content of various products.
• Animal Feed: Microalgae are used as a nutritional supplement in aquaculture for fish and animal feed.
• Environmental Remediation: Microalgae have the ability to absorb pollutants from water and can be employed in wastewater treatment plants or for industrial wastewater cleaning.
• Carbon Dioxide Capture: Microalgae can absorb carbon dioxide from the atmosphere and produce oxygen in the process. This can contribute to reducing greenhouse gases and be used for air purification processes.
• Pharmaceutical Applications: Microalgae produce various bioactive compounds that can be utilized in the pharmaceutical industry for drug and medical product development.
• Bioplastics: Microalgae produce carbohydrates such as starch and sugars, which can be used as raw materials for the production of biodegradable plastics (bioplastics).
• Biosensors/Toxicity Testing: Microalgae are sensitive to toxins and environmental pollutants. By monitoring changes in their growth, photosynthesis activity, and fluorescence, they can serve as biosensors for detecting toxicity in water bodies and environmental samples.

In current and past research projects, we have specifically focused on the biotechnological application of microalgae under the following themes:

• Immobilization and cultivation of microalgae for the production of valuable substances (e.g., astaxanthin, polyunsaturated fatty acids) and biofuels
• Extraction and Immobilization of bioactive compounds
• Investigation of growth promotion through microalgae-bacteria interactions
• Biofunctionalization of material surfaces (e.g., textiles)
• Immobilization of microalgae for biosensor applications

Example Projects:

Project “Tex-As”

The aim of the project was to develop a flow-through, textile-based photobioreactor. This system is designed to be integrated into aquaculture facilities to remove excess nutrients such as nitrate and phosphate from feed residues and animal waste. The algae biomass produced serves as live feed for certain animal species, such as shrimp. The model organism used was the microalga Chlorella vulgaris, chosen for its robustness and rapid growth rate. Using the Sol-Gel process, the microalga was successfully immobilized on textile carriers. More information on the project can be found here: Project “Tex-As”.

Biosensor Applications & Toxicity Testing

Chlorophyll, the natural pigment in plants and algae, is not only essential for photosynthesis but also serves as a biosensor for detecting pollutants. By measuring the reduction in chlorophyll autofluorescence in the presence of a contaminant, the level of pollution in the environment can be quantified. In previous research, we immobilized microalgae in small alginate spots, stabilized by aminofunctionalized SiO₂ sols, and used them for toxicity testing, determining the decrease in fluorescence.

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ANSPRECHPARTNER:
Dr. Ulrich Soltmann
Fachsektion Dresden – “Funktionelle Schichten”
Tel.: 0351 / 2695 343
E-Mail: soltmann@gmbu.de