Research on Semiquantification of Lethal Toxin at the Bottom of Reactors for Clostridium sordellii Culture

Clostridium sordelli veterinary vaccine is made by cultivating the microorganism in large industrial bioreactors and purifying the toxin from culture supernatants. The harvesting time is currently established as a function of bacterial growth, but this time is not always associated with the maximum concentration of toxin present in the supernatant. As a result, it is simple to determine the total amount of toxin produced from batch to batch. Furthermore, the toxin concentration is currently measured using in vivo LD50 methods, and results can be obtained only after 72 hours, when the bioreactor has already been stopped. Moreover, the method is time-consuming and necessitates the use of a large number of experimental animals. The development and application of a latex agglutination reagent for semi-quantification of Clostridium sordelli lethal toxin (TcsL) in industrial bioreactors are described. The reagent was developed and characterised in our laboratory, with a detection limit of 8ng of toxin per ml of culture supernatant, and then validated in actual industrial conditions. The use of such a speedy (i.e., in minutes) and simple reagent will allow for real-time monitoring of the culture, standardising the optimal end-point for harvesting in terms of toxin quantity. As a result, the efficiency of TcsL industrial production may be improved immediately.