Fermentation development experimental design

This article presents the design and implementation of a software sensor for the continuous determination of substrate concentration based on a simple model of a fed-batch fermentation process and the available signals of two other sensors—one for on-line biomass determination (7) and the other for on-line ethanol determination (8)—developed in previous works. The software sensor proposed provides a continuous signal that can be used in a control loop to manipulate the substrate feed flow in order to maintain almost constant substrate concentration and obtain an excellent level of productivity and yield during all of the process, as shown in experimental control strategy studies in previous works (9). 

Eqnations of this form can be written for each of the various products of the reaction, as well as for consnmption of the limiting substrate. Additional stoichiometric relations can also be developed for other species that are ntilized as nonlimiting substrates by the microorganism nndergoing fermentation. However, because the stoichiometry associated with the production of biomass is well established for only a very few simple fermentations, biochemists and others engaged in the design of bioreactors find it useful to employ the concept of yield coefficients in their efforts to analyze the performance of proposed bioreactors. In essence, these researchers determine the yield coefficients experimentally in a manner akin to the technique of eliminating time as a variable in considerations of competitive and consecutive reactions (see Chapter 9). 

The specially designed software, called olfaction software, controls the PC-based data acquisition and automated operation of all these cycles. The software has got features like programmable sequence control, dynamic fermentation profile display, datalogging, alarm annunciation, data archival, etc. The software has been developed in LabVIEW of National Instruments. Experimental conditions are as follows ... 

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