Monitoring microbial bioprocesses for metabolite concentrations using Raman spectroscopy and surface enhanced Raman spectroscopy

Student thesis: Doctoral ThesisDoctor of Philosophy


Raman spectroscopy is a vibrational spectroscopic technique which is complementary to infrared spectroscopy (IR). In contrast to IR which measure the absorbance of IR light by molecules, Raman spectroscopy measure the inelastic light scattered from molecules when they are excited by a monochromatic light source; the wavelength of which is chosen according to the specific application. Although discovered in the early 20th century, the availability only recently of relatively low cost instruments, due to continual technological advancements, is moving Raman spectroscopy out of the physics/chemistry world into the biological realm. This thesis describes the many Raman techniques available including surface enhanced spectroscopy and highlights their exploitation in metabolic fingerprinting and the analysis of specific metabolites in microbial fermentation broths. Univariate and multivariate data analyses were used to analyse the complex multivariate spectral data. These included peak integration for metabolite quantification, and principal component analysis and hierarchical cluster analysis for metabolite discrimination.
Date of Award2006
Original languageEnglish
Awarding Institution
  • Aberystwyth University
SupervisorRoy Goodacre (Supervisor)


  • Raman spectroscopy
  • metabolomics
  • fermentations
  • Online monitoring

Cite this