biocatalyst can be avoided by making the pores sufficiently small, i.e. smaller than the
critical cluster size.
Selection of the mode of operation for a specific solid-to-solid bioconversion, batch at
high concentrations of undissolved substrate or continuous, is often based on the costs
(per kg of product produced). By assuming that in both batch and continuous solid-to-
solid bioconversions the bioconversion is rate limiting, and by introducing a number of
simplifications, the costs of batch operation were compared with the costs of continuous
operation. This revealed that a batch system can only compete with a continuous system
if both the conversion is 100% and the productivity of the biocatalyst is maximal.
ACKNOWLEDGEMENTS
This work was financially supported by the Ministry of Economic Affairs, the Ministry of
Education, Culture and Science, the Ministry of Agriculture, Nature Management and
Fishery in the framework of an industrially relevant research programme of the
Netherlands Association of Biotechnology Centres in the Netherlands (ABON).
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