Productivity enhancement of B. subtilis by cascade continuous fermentation
The majority of microbial fermentations are performed in batch or fedbatch mode, further increasing energy consumption and steps, limiting the productivity, conducting high costs. In some cases, these limitations are based on the equipment and technologies available . The successful establishment of open production process based on continuous mode will lead to reducing the production costs of industrial bio-products like biostimulants and biofertilizers. The most of interest products obtained by Bacillus spp are produced during the stationary phase and when spores are formed. To solve this limitation, a continuous cascade mode in a multi-stage fermentation process was applied. Before establishing the continuous mode, the growth and biomass yield using sucrose, glycerol, and glucose was characterized by testing the optimal carbon source in batch mode with a Bionet’s F0-BABY Multibioreactor.
The strategy for the continuous fermentation in cascade mode was applying in two bioreactors, the chemostat mode in exponential phase in the bioreactor 1 and for the sporulation the bioreactor 2 was used for a semi-continuous strategy by cycles withdrawing the final broth to a storage tank at 4ºC, previously to the addition of preservatives. For the chemostat process a range of dilution rates between 0.1-0.6 h-1 was characterized, and for the semi-continuous cycles at intervals of 8-10 h were used. The main objective of this study is to present our current research in the development of continuous fermentation processes applying scalable and reliable technologies using a Bionet’s F0-BABY Multibioreactor with a Continuous Process Module.