Growth Medium Considerations for the Scale-Up of S-Layer Protein Production by Bacillus brevis 47

Bacillus brevis 47 is known to secrete 16 g/L of S-layer proteins (Wight et al., 1992) and therefore has great potential for the production of high levels of secreted heterologous proteins of commercial value. Investigations into the nutritional regulation of S-layer protein production should facilitate the production of foreign proteins whose genes are under the control of S-layer promoters. Polypeptone has been identified as the key nutrient for the stimulation of S-layer secretion (Shaku et al., 1980). Given the heterogeneous nature of this nutrient it should be possible to employ less expensive nitrogen sources, given medium cost considerations when scaling-up a commercial process.