초록
<P><B>Abstract</B></P> <P>The aim of this study was to propose kinetic parameters of a bacterial growth and its products formation as functions of environmental conditions. Hence, the effect of temperature and initial moisture content on bacterial growth and rhamnolipid biosurfactant production by <I>Pseudomonas aeruginosa</I> were investigated in the first step. A mixture of corn bran and corn germ was used as substrate in small glass packed-bed laboratory bioreactors. Results showed the highest rhamnolipid production rate was observed in stationary phase and the highest growth and rhamnolipid production were at 35°C and initial bed moisture of 70%. Then, kinetic parameters of the bacteria were determined using the fitting of kinetic models to experimental results of cumulative CO<SUB>2</SUB>, rhamnolipid amount and metabolic water production. After that, the kinetic parameters <SUB> m C <SUB> O 2 </SUB> </SUB> , <SUB> m R L </SUB> , <SUB> m w </SUB> and <SUB> Y X / W </SUB> were considered with constant values while <SUB> μ m </SUB> , <SUB> X m </SUB> , <SUB> Y X / C <SUB> O 2 </SUB> </SUB> and <SUB> Y R L / X </SUB> were presented as functions of environmental conditions, by modifying a model and using 3-dimensional curve fitting. Finally, in order to validate the obtained kinetic parameters and functions, transport phenomena in a packed-bed bioreactor were modeled in 2-dimensions. The model results were verified by the experimental results obtained from a 3-liter glass packed-bed bioreactor and the validation was satisfactory.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effect of environmental conditions on bacterial respiration and bioproducts in SSF. </LI> <LI> Determining optimal environmental conditions for rhamnolipid production in SSF. </LI> <LI> Modifying a model to correlate bacterial kinetic parameters to environmental conditions. </LI> <LI> Comparison between the proposing modified kinetic parameters to other similar model. </LI> <LI> 2-Dimensional modeling for a 3-L packed-bed bioreactor to validate models. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>