Clostridium Detoxification

Detoxification. The process by which bacterial toxins are converted to harmless toxoids. Formalin is used to detoxify the toxins of both Corynebacterium diphtheriae and Clostridium tetani. The detoxification may be performed either on the whole culture in the fermenter or on the purified toxin after fractionation. 

Detoxification. The process by which bacterial toxins are converted to harmless toxoids. Formaldehyde is used to detoxify the toxins of Corynebacterium diphtheriae, Clostridium botu-linum and Cl. tetani. The detoxification may be performed either on the whole culture in the fermenter or on the purified toxin after fractionation. Traditionally the former approach has been adopted, as it is much safer for the operator. However, the latter gives a purer product. The pertussis toxin used in acellular vaccines may be detoxified with formaldehyde, glutaraldehyde, or both, hydrogen peroxide or tetranitromethane. In the case of genetically detoxified pertussis toxin, a treatment with a low concentration of formaldehyde is still performed to stabilize the protein. 

The effect of detoxification of the medium by removal of toxic compounds with UF membranes was demonstrated by Boyaval et al. [36] in the fermentation of propionic acid. UF runs led to an eightfold increase in volumetric productivity relative to fed batch experiments. The effectiveness of membrane bioreactors in the lowering of toxicity of the compounds involved in the bioconversion system was demonstrated by Edwards and co-workers [159]. An eightfold increase in the removal of phenoHc compounds from effluents was observed when polyphenoloxidase was immobilized in a capillary poly(ether)sulfone membrane as compared to the use of the free enzyme. Butanol recovery from the fermentation medium with organic solvent extraction or membrane solvent extraction led to similar results, both processes leading to decreased product inhibition. Due to the low toxicity of the extractive solvent used (isopropyl myristate) on Clostridium beyerinckii cells, no protective effect of the membrane was observed. However, precipitates observed in two-Hquid phase extraction were not observed... 

Bennett GN, San KY (2001) Microbial formation, biotechnological production and application of 1,2-propanediol. Appl Microbiol Biotechnol 55 1—9 Bermejo LL, Welker NE, Papoutsakis ET (1998) Expression of Clostridium acetobufyticum ATCC 824 genes in Escherichia coli for acetone production and acetate detoxification. Appl Environ Microbiol 64 1079-1085 Beronio PB Jr, Tsao GT (1993) Optimization of 2,3-butanediol production by Klebsidla oxytoca through oxygen transfer rate control. Biotechnol Bioengin 42 1263-1269... 

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