KINETICS OF GROWTH OF ASPERGILLUS-NIGER DURING SUBMERGED, AGAR SURFACE AND SOLID-STATE FERMENTATIONS

The effect of initial glucose concentration (30-450 g/litre) on the gr owth of Aspergillus niger 10 in submerged (SMF), agar surface (ASF) an d solid state (SSF) fermentations was examined. Biomass production and specific growth rate were considerably less sensitive to changes in i nitial glucose concentration in SSF compared to either ASF or SMF. In all cases, maximum specific growth rates (0.323, 0.247 and 0.134 1/h f or SSF, ASF and SMF, respectively) were obtained with the lowest initi al glucose concentration employed (50 g/litre for SSF and 30 g/litre f or both ASF and SMF). The rates of glucose uptake in SSF were consider ably less affected by initial glucose concentrations when compared wit h ASF and SMF. Complete consumption of glucose in SSF, ASF and SMF was observed when glucose was applied at initial concentrations of 200, 1 50 and 100 g/litre, respectively. These results indicate that SSF is m ore suitable than either ASF or SMF for the growth of filamentous fung i, especially under conditions where catabolite repression applies (e. g. due to high glucose concentrations). (C) 1998 Elsevier Science Ltd.