Reaction Engineering Studies on Microbial Riboflavin Production with Small-Scale Stirred-Tank Reactors

Andrea Vester, doctoral thesis Technische Universität München, 2009

Parallel operated stirred-tank bioreactors on a millilitre-scale were applied for reaction engineering analysis of new riboflavin production strains and fermentation media. Using the example of the microbial riboflavin fed-batch production process with Bacillus subtilis, an efficient method for statistically significant discrimination of different production strains was established by means of this prototype system. The parallel optimization of the initial medium composition approved the already established industrial production medium as best. The experimental studies showed that technical modifications of the parallel reactor system prototype – for example a new pH-sensor and control, individual online temperature and foam control - are considered as reasonable for reaction engineering studies of microbial production of riboflavin.


  • Vester A, Hans M, Hohmann H-P, Weuster-Botz D (2009): Discrimination of riboflavin producing Bacillus subtilis strains based on their fed-batch process performances on a millilitre scale. Appl Microbiol Biotechnol 84: 71-76.