Clostridium in Biotechnology and Food Technology

Abstract

The genus Clostridium contains widely diverse species which have been shown to be associated with foodborne illness as well as solvent production (Blaschek, 1999). C. perfringens is representative of a clostridial species which is associated with food poisoning, while non-toxinogenic C. beijerinckii has important industrial and biotechnological potential because of its ability to produce acetone and butanol during fermentation of carbohydrates. The development of genetic systems for the clostridia was recently reviewed (Blaschek and White, 1995). Electroporation induced transformation has been shown to have considerable potential for introducing DNA into a wide variety of gram⁺ and gram⁻ bacterial species (Dower et al., 1992) and electroporation protocols are available for previously non-transformable clostridial strains (Chen et al., 1996). However, the transformation efficiencies appear to vary greatly among different species and strains. It has been suggested that DNase and restriction enzyme activity are common barriers to successful transformation of the clostridia. The cell wall may also represent a barrier to DNA uptake in C. perfringens (Kim and Blaschek, 1989). As we learn more about mechanisms and factors involved in transforming various bacteria, protocols for overcoming these obstacles will likely emerge. Electroporation protocols have been developed for the clostridia which are based on using polyethylene glycol (PEG) in the shocking menstruum. During electroporation-induced transformation, PEG may limit cytoplasmic leakage and, via exclusion of the aqueous phase, help to push the plasmid DNA into the cell and consequently increase cell viability and transformation efficiency.