Email updates

Keep up to date with the latest news and content from Biotechnology for Biofuels and BioMed Central.

Open Access Research

Real-time understanding of lignocellulosic bioethanol fermentation by Raman spectroscopy

Shannon M Ewanick1, Wesley J Thompson2, Brian J Marquardt2 and Renata Bura1*

Author Affiliations

1 School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA

2 Applied Physics Laboratory, University of Washington, Seattle, WA, USA

For all author emails, please log on.

Biotechnology for Biofuels 2013, 6:28  doi:10.1186/1754-6834-6-28

Published: 20 February 2013

Abstract

Background

A substantial barrier to commercialization of lignocellulosic ethanol production is a lack of process specific sensors and associated control strategies that are essential for economic viability. Current sensors and analytical techniques require lengthy offline analysis or are easily fouled in situ. Raman spectroscopy has the potential to continuously monitor fermentation reactants and products, maximizing efficiency and allowing for improved process control.

Results

In this paper we show that glucose and ethanol in a lignocellulosic fermentation can be accurately monitored by a 785 nm Raman spectroscopy instrument and novel immersion probe, even in the presence of an elevated background thought to be caused by lignin-derived compounds. Chemometric techniques were used to reduce the background before generating calibration models for glucose and ethanol concentration. The models show very good correlation between the real-time Raman spectra and the offline HPLC validation.

Conclusions

Our results show that the changing ethanol and glucose concentrations during lignocellulosic fermentation processes can be monitored in real-time, allowing for optimization and control of large scale bioconversion processes.