ABSTRACT
Introduction .................................................................................................................................... 339 Historical Background ................................................................................................................... 339 Metabolism ....................................................................................................................................340 Phylogeny and Taxonomy .............................................................................................................. 343 Pathogenicity .................................................................................................................................. 343 Biotechnology ................................................................................................................................346 Handling and Molecular Biology Techniques ...............................................................................348 Acknowledgments .......................................................................................................................... 350 References ...................................................................................................................................... 350
Clostridium is one of the largest bacterial genera, including more than 150 validly described species. Among these are several with enormous biotechnological potential (e.g., for production of biofuels, bulk chemicals, and important enzymes, as well as for usage in cancer treatment) and also a few well-known pathogens. However, even some of their toxins proved meanwhile to be valuable in medical and cosmetic applications. Clostridia thus belong to the avant-garde of industrially useful microbes. Members of this genus, in general, stain Gram-positive, are more or less strictly anaerobic bacteria, employ an impressive number of varying fermentation routes, and are able to degrade numerous natural and articial substances. Due to required precautions for excluding oxygen during handling, clostridia were for a long time virtually inaccessible at the genetic level. This situation has completely changed. Gene cloning, DNA transfer, gene expression modulation, and gene knockout systems have been successfully established. Thus, the road is paved for further elucidation and commercial exploitation of the enormous metabolic potential of the clostridia.
