Evaluation and optimization of cholera toxin production by Vibrio cholerae in different time periods.

Vibrio cholerae is one of the most studied bacterial toxins in the AB5 family and is widely used as a potent mucosal adjuvant because of its ability to enhance the immune response to the antigen injected with it. This toxin consists of two subunits, a pentameric subunit called subunit B, and a subunit A. This toxin enters the target cell by binding to the GM1 ganglionic receptor . In this study Vibrio cholerae were cultured in 100 ml of AKI and Craig's medium in two groups. One group was then incubated at 37 ° C and the other group was incubated at 30 ° C for 72 h. All media were sampled on a regular basis from the beginning of the incubation period to evaluate the toxin production. Finally, the amount of toxin production was evaluated by ELISA GM1 test. The results showed that the bacteria in both culture medium were capable of producing relatively high levels of toxin. The highest toxin production was observed in Craig's medium at 30 ° C after 50 h. The results of ELISA GM1 test showed that the bacterium had the highest production in Craig's medium after 50 hours at 30 ° C, while the highest toxin production in AKI medium after 24 hours at 37° C.