15A-11 |
Monitoring a bioprocess for ethanol production using FTIR and FT-Raman spectroscopy |
S. SAKHAMURI, J. M. K. Irudayaraj, and A. Demirci. Dept. of Agricultural & Biological Engineering, The Pennsylvania State Univ., 109 Agricultural Engineering Bldg., University Park, PA 16802 The ability to control fermentation is of paramount importance in the optimization of biomass and product synthesis. Parameters such as biomass, nutrient, by-product and product concentrations play a major role in modulating the kinetics during fermentation. Several labor-intensive analytical techniques are required to measure biomass, nutrients, and product. An increase in the efficiency of measurement and monitoring procedures has a high potential to result an increase in the efficiency of these bioprocesses. The application of fourier transform infrared spectroscopy (FTIR) and fourier transform Raman (FT-Raman) spectroscopy for process and quality control of fermentative production of ethanol was investigated. FTIR and FT-Raman spectroscopy along with multivariate techniques were used to simultaneously determine glucose, ethanol, and optical cell density of Saccharomyces cerevisiae during ethanol fermentation. The potential of these methods was examined by comparison with a high-performance liquid chromatography (HPLC) method. Spectral wavenumber regions were selected for Principal Least Square (PLS) regression and Principal Component Regression (PCR) and calibration models for glucose, ethanol and optical cell density were developed for culture samples. Correlation coefficient (R2) value for the prediction for glucose and ethanol was more than 0.9 using various calibration methods. The standard error of prediction for the PLS-1st derivative calibration models for glucose, ethanol and cell OD were 1.938 g/L, 1.150 g/L, and 0.507, respectively. Prediction errors were high with FT-Raman spectroscopic technique since the Raman scattering of the cultures was weak. Results indicated that FTIR spectroscopy could be used for rapid detection of glucose, ethanol and optical cell density in S. cerevisiae culture during ethanol fermentation.
Session 15A, Biotechnology
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