Prof Martin Warren – University of Kent
Dr Hartwig Schroeder – BASF
Dr Oskar Zelder – BASF
Vitamin B12 is unique among the vitamins in that it is exclusively made only by certain prokaryotes.
Moreover, the chemical complexity of the molecule also means that it cannot be produced by chemical synthesis and thus vitamin B12 remains, along with vitamin B1, one of the few nutrients that is produced commercially by bacterial fermentation. The industrial production of B12 is further hindered by the fact the yields of B12 produced by bacteria are comparatively low and hence the nutrient has to undergo an exhaustive purification procedure. In this project we aim to develop a simpler, one-step isolation methodology through the use of a re-useable B12-binding protein system. Thus, for this project we will investigate the properties of a range of B12-binding proteins, especially those from thermophiles, halophiles and acidophiles in order to find a suitably stable protein that can be utilised for this process. After further kinetic and structural characterisation of the best identified protein we will aim to improve its properties through protein engineering in order to maximise its potential for commercial use and replace the current cumbersome extraction procedures that are currently in place. The project will therefore involve the amplification, cloning and expression of genes that encode for B12 binding proteins such as BtuF and BtuG and the subsequent isolation and characterisation of the proteins in terms of their stability. The project has the potential for significant impact as the binding proteins will allow for a simple onestep purification of the nutrient that will significantly improve not only the isolation time but also the purity of this high-value commodity, which retails around $10,000 per Kg. The project will benefit from the expertise associated with BASF in the optimisation of isolation procedures and the construction of protein-based affinity systems for large-scale production.