Sunday, April 29, 2007

Novel strategy for the production of a generic fermentation feedstock based on particulate bioprocessing

Carolina Botella, Ruohang Wang, Apostolis Koutinas, and Colin Webb. School of Chemical Engineering and Analytical Science, University of Manchester, PO Box 88, Sackville Street, M60 1QD, Manchester, United Kingdom

There is an increasing social and political demand to establish renewable feedstocks and replace traditional chemical processes with more benign and sustainable, biotechnology based, processes. However biotechnological processes generally require the use of relatively expensive raw materials and large amounts of water and are therefore often uncompetitive. Research in the Satake Centre for Grain Process Engineering is aimed at overcoming these limitations through the development of generic fermentation feedstocks using cereals as raw material.

As part of this goal we are developing a novel process strategy (particulate bioprocessing) based on solid state fermentation for the production of a generic microbial feedstock that can be used for the production of value-added chemicals or biofuels.

The system proposed involved a packed bed of partially pearled whole wheat grains which is used for fermentation by the fungus Aspergillus awamori.  Intermittent addition of water during the cultivation helps to maintain moisture and temperature levels, and is also used to extract soluble components.  The extracts obtained have high glucose and free amino nitrogen concentrations and have been used for subsequent fermentations to produce the biodegradable plastic PHB (Polyhydroxybutyrate) and for ethanol production

Results of subsequent fermentations using the extracts have shown that they contain the full range of nutrients required by a variety of microorganisms. The processing strategy based on particulate bioprocessing therefore has the potential to produce through, simple in-situ extraction, a generic feedstock that could be used for the production of a wide range of petrochemical replacements.