PUB - Publikationen an der Universität Bielefeld

In this thesis a biorefinery concept has been developed, where the phototrophic protist/microalgae Euglena gracilis was used to generate simultanously the high value products alpha-tocopherol, paramylon (a ß-1,3-glucane) and lipids. Therefore an upstrean process for a low cost sanitisation of outdoor photobioreactors has beed established before the cultivation was performed in a new designed medium with less than 2 gramms solids per litre at a pH value of 2-3. The cultivation process with 5% CO2 was a repeated batch in combination with the circadian rhythm of E. gracilis, where harvesting of around 20 % slurry was done every night with a cell cettler. After 8 days cultivation in thin layers of 1-2 cm culture thickness biomas concentrations of 5,3-6,7 g/L dry cell weight was generated which contains around 40% paramylon, 30% lipids with a high omega-3-fatty acid content and 2mg/g alpha-tocopherol. Additionally a new photobioreactor study was developed with several features like biomass concentration in the reactor before harvesting. Further goals have been achived, too.