Optimization of the Production of Vaccine Epitopes from Clostridium novyi Alpha-Toxin Using Strains of Recombinant Escherichia coli.

Clostridium novyi is a common pathogen in domestic animals and humans, and alpha-toxin is the main cause of its pathogenesis. Because it is a fastidious organism, obtaining alpha-toxin is expensive. Therefore, we proposed an in silico study to synthesize epitopes in cultures of Escherichia coli BL21 pLysS (DE3). First, we used a stirred-tank bioreactor, developing a dry mass yield (DMY) of 0.77 g/L in batch cultures and 1.03 g/L in fed-batch cultures, without acetic acid production. With scale-up using a system without mechanical agitation, there was a higher DMY (1.20 g/L) with 0.56 mmol/mL of alpha-toxin epitope 1 (DE3/Ep1) and 0.61 mmol/mL of alpha-toxin epitope 2 (DE3/Ep2), with a similar profile for O2 consumption, glucose, and no acetic acid production. The kinetic parameters µ(h-1), YX/S, YP/S, QP, and QX did not differ significantly; however, the kinetic data were superior. Our results suggest that in silico tools allow epitope selection and bioprocess standardization. This system provides cost savings and technological advances for the veterinary vaccine industry.