BEJ_changedversion_280308.pdf (403.93 kB)
Download file

Physiological effects of the addition of n-dodecane as an oxygen vector during steady-state Bacillus licheniformis thermophillic fermentations perturbed by a starvation period or a glucose pulse

Download (403.93 kB)
journal contribution
posted on 08.01.2009, 17:06 by Teresa Lopes da Silva, Alberto Reis, J. Carlos Roseiro, Christopher Hewitt
The effect of the presence of n-dodecane as a potential oxygen vector during oxygen limited continuous cultures of a Bacillus strain was studied, under extreme nutrient supply conditions: glucose excess, limitation and starvation. The addition of n-dodecane to the aqueous phase of a mechanically agitated and aerated fermentation increased the kLa by up to 35%. The n-dodecane additions to B. licheniformis cells during starvation (oxygen limitation with concomitant glucose starvation) caused a severe detrimental progressive change in cell physiological state with respect to cytoplasmic membrane polarisation and permeability which was mitigated against by alleviating either the oxygen limitation (by increasing the mean energy dissipation rate or by the addition of n-dodecane as an oxygen vector) or by alleviating the carbon limitation (by resuming the carbon feed or by the addition of a glucose pulse). Further that during periods of excess glucose (glucose pulse) a much higher kLa was required to prevent the onset of anaerobic mixed acid fermentation than could be provided by the addition of n-dodecane alone. N-dodecane can be used to increase the kLa when added in sufficient quantities to the aqueous phase of a mechanically agitated and aerated bioreactor but the magnitude of this increase is process and vessel geometry specific.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Chemical Engineering

Citation

LOPES DA SILVA T ... et al, 2008. Physiological effects of the addition of n-dodecane as an oxygen vector during steady-state Bacillus licheniformis thermophillic fermentations perturbed by a starvation period or a glucose pulse. Biochemical Engineering Journal, 42 (3), pp. 208-216

Publisher

© Elsevier

Version

AM (Accepted Manuscript)

Publication date

2008

Notes

This article was published in the journal, Biochemical Engineering Journal [© Elsevier] and the definitive version is available at: www.elsevier.com/locate/bej

ISSN

1369-703X

Language

en