Tetanus toxin production in soy-based medium: nutritional studies and scale-up into small fermentors.
OBJECTIVE
To further improve the soy-based medium, devoid of animal and dairy products, for a production of tetanus toxin by nutritional studies and to scale-up the Clostridium tetani process into small fermentors.


RESULTS
Optimum production of tetanus toxin did not require addition of pantothenic acid, thiamine, riboflavin, pyridoxine, biotin and uracil, growth factors used by previous investigators. Furthermore, l-tyrosine and l-cysteine could be eliminated from our soy-based medium without effect. Seven carbon sources were compared with glucose in the soy-based medium, but none was found to be superior to glucose. The process was successfully scaled-up into 250-ml bottles, 1-l bottles and 1-l fermentors.


CONCLUSIONS
Quite remarkably, when comparing the tetanus production process in our soy-based medium with the traditional animal/dairy-containing media, our medium does not require addition of expensive vitamins, uracil or carbon sources other than glucose. Furthermore, the l-tyrosine and l-cysteine components could be eliminated, making the medium (Hy-Soy, glucose, powdered iron and inorganic salts) much more simple and economical. The successful scale-up from test tubes into 1-l fermentors allows us to predict that further scale-up into large fermentors will be successful.


CONCLUSIONS
Toxoid preparations made from toxin produced with animal and dairy products can contain undesirable contaminants such as the prion causing bovine spongiform encephalopathy (BSE; mad cow's disease) or antigenic peptides that stimulate anaphylactic reactions and other undesirable immune reactions in immunized hosts. Our vegetable-based process avoids such unfortunate possibilities. The medium, having been made simpler and less expensive, and shown to be scaleable from test tubes into small fermentors, should be excellent for large scale production of tetanus toxin.
Demain
A L
AL
Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA. ademain@drew.edu
George
S
S
Kole
M
M
Gerson
D F
DF
Fang
A
A
D050260:Carbohydrate Metabolism; D003017:Clostridium tetani / Q000254:growth & development / Q000378:metabolism*; D016895:Culture Media, Serum-Free / Q000737:chemistry* / Q000191:economics; D007218:Industrial Microbiology / Q000379:methods*; D007287:Inorganic Chemicals / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D012492:Salts / Q000378:metabolism; D030262:Soybean Proteins / Q000378:metabolism; D013744:Tetanus Toxin / Q000096:biosynthesis*
D016895:Culture Media, Serum-Free; D007287:Inorganic Chemicals; D012492:Salts; D030262:Soybean Proteins; D013744:Tetanus Toxin; D007501:Iron