Continuous Production of Acetic Acid from CO₂ in Repeated-Batch Cultures Using Flocculated Cells of Acetobacterium woodii

Abstract

The biological utilization of CO₂ in the production of acetic acid in anaerobic fermentations of Acetobacterium woodii was studied in a bubble-column bioreactor. To increase the productivity of acetic acid a repeated-batch culture technique was developed by introducing concentrated cells using a synthetic polymeric flocculant. The effects of the operating conditions of gas flow rate, cell density and medium composition on volumetric productivity of acetic acid were examined. At suboptimal operating conditions the production rates of various cultivation schemes were examined. This approach is especially valuable for simplification of the process and utilization of the energy required for the separation of the cells from the liquid content.