Biorefineries have reignited interest in anaerobic fermentations, with biobutanol production being the principle driver. Biobutanol was historically produced in Clostridium acetobutylicum, however, the production of butanol was subsequently converted to a petrochemical-based process. Due to the volatility of the oil market, the biobutanol process is having a resurgence.
This article will discuss the adaptation of m2p-labs’ BioLector® technology for anaerobic fermentations. BioLector is a high-throughput fermentation platform with online-monitoring capabilities. This technology provides 48 or 96 parallel fermentations in the standard microplate format, it also detects online biomass and fluorescent proteins as well as pH and DO values during fermentation.
As opposed to traditional stirred tank bioreactors, BioLector does not require cleaning, sterilization, or calibration procedures or tube connections. It has been demonstrated in aerobic cultures that the results of fermentations in BioLector microplates are easily scalable to stirred tank bioreactors. It can thus be inferred that the optimized process conditions in the BioLector can be rapidly transferred to larger-scale bioreactors.
In general, anaerobic fermentations can already be performed with the basic BioLector technology by connecting nitrogen or carbon dioxide to the BioLector incubation chamber. The major drawback of this simple system is that relatively large gas flows in the range of 100 mL/min are required and the applied gas can diffuse into the laboratory atmosphere.
Additionally, transfer of the microplate from the anaerobic bench to the BioLector poses the risk of gas contamination and a return to aerobic conditions. In the case of obligate anaerobic microorganisms, this situation is a knock-out criterion. To circumvent this problem, the Anaerobe Chamber for the BioLector was developed.
The Anaerobe Chamber seals the microplate completely against ambient air. A removable transparent chamber cover allows easy viewing of the microplate and the cultures and also provides access to the microplate during fermentation for sampling or feeding (Figure 1).