A method for at-line quality assessment of a cultivation process is sought to
1) enable improved process control,
2) enable faster detection of batch end point, and
3) enable immediate quality assessment of final product.
Fluorescence excitation-emission measurements are used because they are known to reflect important properties of the fermentation process. Several samples from many batches are obtained and are measured on an at-line multi channel fluorescence detection system (BioView®).
Example of an excitation/emission fluorescence landscape.
The data are available in zipped MATLAB 7 format and stored as dataset objects (see freeware dataset object at www.eigenvector.com). If you use the data we would appreciate that you report the results to us as a courtesy of the work involved in producing and preparing the data. Also you may want to refer to the data by referring to
P. P. Mortensen and R. Bro. Real-time monitoring and chemical profiling of a cultivation process. Chemom.Intell.Lab.Syst. 84:106-113, 2006.
Each fluorescence landscape from the sensor is obtained using15 excitation filters in the range from 270 to 550 nm with a spectral resolution of 20 nm, and 15 emission filters range from 310 to 590 also with a spectral resolution of 20 nm. All filters have a maximum half-width of 20 nm.
The reference analysis for the produced protease is based on the protease degrading N,N-dimethyl-casein. Amino acids liberated by the action of the enzyme reacts with 2,4,6 trinitrobenzene sulfonic acid to form a colored complex. The amount of complex is correlated to the enzyme activity and is determined spectroscopically. The reference values given here are not the actual activity measurements, but a related quality parameter that is highly correlated to activity.
The data are split in a calibration set and a test set consisting of data from three normal batches. The test set is less variable than the calibration data.