Journal of Industrial Microbiology & Biotechnology

, Volume 34, Issue 8, pp 561–566

On-line biomass measurements in bioreactor cultivations: comparison study of two on-line probes

  • K. Kiviharju
  • K. Salonen
  • U. Moilanen
  • E. Meskanen
  • M. Leisola
  • T. Eerikäinen
Original Paper

DOI: 10.1007/s10295-007-0233-5

Cite this article as:
Kiviharju, K., Salonen, K., Moilanen, U. et al. J Ind Microbiol Biotechnol (2007) 34: 561. doi:10.1007/s10295-007-0233-5

Abstract

Two on-line probes for biomass measurement in bioreactor cultivations were evaluated. One probe is based on near infrared (NIR) light absorption and the other on dielectric spectroscopy. The probes were used to monitor biomass production in cultivations of several different microorganisms. Differences in NIR probe response compared to off-line measurement methods revealed that the most significant factor affecting the response was cell shape. The NIR light absorption method is more developed and reliable for on-line in situ biomass estimation than dielectric spectroscopy. The NIR light absorption method is, however, of no significant use, when the cultivation medium is not clear, and especially in processes using adsorbents or solid matrix for the microorganism to grow on. The possibilities offered by dielectric spectroscopy are impressive, but the on-line probe technology needs to be improved.

Keywords

BiomassCell density measurementDielectric spectroscopyNear infrared light absorptionOn-lineViability

Copyright information

© Society for Industrial Microbiology 2007

Authors and Affiliations

  • K. Kiviharju
    • 1
  • K. Salonen
    • 1
  • U. Moilanen
    • 1
  • E. Meskanen
    • 1
  • M. Leisola
    • 1
  • T. Eerikäinen
    • 1
  1. 1.Laboratory of Bioprocess Engineering, Helsinki University of TechnologyHelsinkiFinland