FTIR spectroscopy applied to bacterial cells as a novel method for monitoring complex biotechnological processes

The acetone-butanol-ethanol (ABE) fermentation is a complex biotechnological process, forming a range of products which is related to the differentiation of the bacterial population in a cell-cycle. Fourier transform infrared (FTIR) spectroscopy was applied to cells from various stages of the process, revealing major differences in the chemical composition of the cells. When processed by a hierarchical cluster analysis, the spectra differed significantly; the statistical distances corresponded to the physiological status as assessed by the products formed and to the degree of morphological differentiation in the population. Thus, IR spectroscopy can serve as an additional means to characterize the physiological status of the microbial culture in a biotechnological process. (C) 1999 Elsevier Science B.V. All rights reserved.