Optimization of Epsilon Toxin Production by Vaccine Strain of Clostridium perfringens Type D in Fermenter

摘要

Enterotoxaemia, an economically important overwhelming disease of small ruminants is pre-vented by epsilon toxoid vaccination. The cost for larger scale toxoid production is high that can be decreased by elevating the in-vitro expression of this toxin. In the present study an attempt was made to raise epsilon toxin production by use of fermenter and improvement of cultural media. The conditions such as amount of inoculums adaptation of C. perfringens type D to various quantities of media, speed and period of agitation, and maintenance of temperature and pH were standardized in fermenter. Simultaneously growth media components commercially available liver and beef extract powder were replaced with fresh caprine heart and liver tissue. Subsequently epsilon toxin titre of the trypsinised harvest was determined in mice after 18 h of incubationit was found that fermenter based cultivation could produce double titre of toxin compared to commercial media in stationary culture. Moreover the replacement of commercially available liver and beef extract powder with fresh caprine heart and liver tissue could produce two times greater toxin titre compared to ordinary production media. Thus the present study provides a potential cursor for achieving high yields of epsilon toxin titres thus for bulk production of toxoid based enterotoxaemia vaccines.