Starting a new genetic system: Lessons from Bacteroides

Despite the fact that genetic manipulation is an essential adjunct of studi es of microbial physiology, many important bacterial species are still not accessible to genetic manipulation. In many cases, the people who know the organism best and have studied its physiology extensively have little exper ience with genetic techniques and are uncertain how to set up a new system. In this article, we describe what we have learned in the process of develo ping a genetic system for Bacteroides spp. and helping to develop genetic t ools for two related species of bacteria: Porphromonas gingivalis and Prevo tella ruminicola. We discuss the relative usefulness of different types of genetic tools and make some suggestions about how to construct them. (C) 20 00 Academic Press.