Bioreaction Engineering


Research positioning

A significant fraction of future commodity chemicals will be produced from renewable biomass. Fermentation will feature as one of the primary conversion technologies in the biorefinery where bulk processing will be the norm. Similar to the conventional refinery, the efficiency of the conversion units will govern the economic viability of the overall process. In this regard we foresee the discipline of bioreaction engineering to play a vital role.  

Our contribution lies in the development, understanding and optimisation of continuous high cell density fermentation processes. We are currently targeting the organic acid platforms, with specific focus on succinic and fumaric acid. We have a keen interest in the self- immobilization characteristics of some organisms where biofilms can be used as a cost effective retainment strategy.  Given our Chemical Engineering background we have a continuous processing focus, where steady state is highly advantageous for mass balance checks and metabolic flux analysis.  

Group Leader : Willie Nicol

Current projects

Production characteristics of shear controlled bacterial biofilm reactors. Deon Brink ([email protected])

High titre and yield succinate production with Actinobacillus succinogenes biofilms using glucose and xylose as substrates. Michael Bradfield ([email protected])

Continuous fumerate production with Rhizopus Oryzae in a novel biofilm fermenter: steady state metabolic flux analysis. Andre Naude ([email protected])

Succinate production in a high cell density  membrane-recycle fermenter using genetically modified Escherichia coli KJ122. Adolf Krige ([email protected])


Brink, H.G., Nicol, W., Succinic acid production with Actinobacillus succinogenes: Rate and yield analysis of chemostat and biofilm cultures, (2014) Microbial Cell Factories, 13 (1), art. no. 111 .

Bradfield, M.F.A., Nicol, W., Continuous succinic acid production by Actinobacillus succinogenes in a biofilm reactor: Steady-state metabolic flux variation, (2014) Biochemical Engineering Journal, 85, pp. 1-7.

Brink, H.G., Nicol, W., The influence of shear on the metabolite yield of Lactobacillus rhamnosus biofilms, (2014) New Biotechnology, 31 (5), pp. 460-467.

Maharaj, K., Bradfield, M.F.A., Nicol, W.,Succinic acid-producing biofilms of Actinobacillus succinogenes: Reproducibility, stability and productivity, (2014) Applied Microbiology and Biotechnology, 98 (17), pp. 7379-7386.

van Heerden, C.D., Nicol, W., Continuous and batch cultures of Escherichia coli KJ134 for succinic acid fermentation: Metabolic flux distributions and production characteristics, (2013) Microbial Cell Factories, 12 (1), art. no. 80.

van Heerden, C.D., Nicol, W., Continuous succinic acid fermentation by Actinobacillus succinogenes, (2013) Biochemical Engineering Journal, 73, pp. 5-11. 

- Author Willie Nicol

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