| Abstract: | Citric acid fermentation – biotechnological problems and possibilities of computer control . Citric acid today is produced almost exclusively by fermentation with the mold Aspergillus niger according to the surface or submerged process. The application of complex raw materials, like molasses, gives rise to considerable waste water burdens as well as to problems with microbiological process control. In order to gain qualitative and quantitative ideas about the metabolic activities of the mold during citric acid fermentation according to the submerged process production fermentors were equipped with several measuring points for the acquisition of physico-chemical changes in the medium and with devices for waste air analysis. The measured values were requested in rotation by an on-line computer and converted to characteristic derivative data. Together with additional analytical laboratory values these data were appropriate for getting a deeper insight into the biochemical events during fermentation. In this way mathematical models could be prepared which supported a better control and optimization of the fermentation course. The knowledge derived from these investigations permitted the extension of the data acquisition and computer system for monitoring and control of all production fermentors. |
