FEMS Microbiology Reviews 63 (1989) 301-326 301 Published by Elsevier FEMSRE 00127 Recent advances in the genetics of the clostridia Michael Young 1, Nigel P. Minton 2 and Walter L. Staudenbauer 3 I Department of Biological Sciences, University College of Wales, Aberystwyth, z Molecular Genetics Group, Division of Biotechnology, PHLS Centre for Applied Microbiology and Research, Porton Down, U.K., and 3 Institut Botanik und Mikrobiologie, Technische Unioersitiit Miinchen, Lehrstuhl fiir Mikrobiologie, Miinchen, F.R.G. Received 2 May 1989 Accepted 16 May 1989 Key words: Clostridium; Plasmid; Transformation; Conjugation; Transposon; Toxins; Fermentation; Gene cloning; Gene structure; Gene expression 1. SUMMARY 2. INTRODUCTION Several laboratories around the world have started work on genetic analysis of clostridia. In- terest in this diverse group of anaerobic organisms has grown with increasing awareness of the be- nefits that may accrue from their biotechnological exploitation. Research to date has focussed on construction of shuttle vectors containing repli- cons from clostridial and streptococcal plasmids, development of methods for transferring genes, and molecular cloning of genes--especially those involved in toxigenicity, fermentative metabolism and polysaccharide utilization. In selected species gene transfer by protoplast transformation, elec- troporation and conjugation has been accom- plished and transposable elements have been introduced. It can be anticipated that our under- standing of the molecular biology of these interest- ing organisms will grow rapidly in the future, bringing with it improved prospects for rational biotechnological exploitation. Correspondence to: M. Young, Department of Biological Scien- ces, University College of Wales, Aberystwyth, Dyfed SY23 3DA, U.K. The genus Clostridium, in which are found mainly rod-shaped, anaerobic, Gram-positive, en- dospore-forming bacteria, is one of the largest genera of prokaryotes. The many different species possess an impressive repertoire of dissimilatory metabolic pathways. Their metabolic diversity is of considerable interest to the biotechnologist. Past attention has mainly been focussed on the biologi- cal production of useful chemical fuels from re- newable biomass [1-3]. More recently, the poten- tial production by clostridia of high value stereo- specific compounds [4], whose chemical synthesis is both difficult to accomplish and cost prohibi- tive, is being explored. In order more fully to exploit the catalytic versatility of these organisms, several groups are starting to investigate their genetics. A primary goal of this research is to provide a satisfactory understanding of the molec- ular mechanisms involved in metabolic control and diversity, so that recombinant DNA technol- ogy may then be used rationally to manipulate metabolic pathways. Here we review current pro- gress toward this goal. Much of the early work concerning mutagene- sis and the collection of mutant strains, isolation 0168-6445/89/$03.50 © 1989 Federation of European Microbiological Societies Downloaded from https://academic.oup.com/femsre/article-abstract/5/4/301/495774 by guest on 15 June 2020