FEMS Microbiology Reviews publishes reviews dealing with all aspects of microbiology that have not been surveyed recently. Reviews should be devoted to topics of current interest and provide comprehensive, critical and authoritative coverage. They should provide new perspectives and critical, detailed discussions of significant trends in the areas being reviewed and may contain elements of a speculative and selective nature. All reviews should address both specialists and the general reader. Whenever possible, reviews should be put into the framework of general microbiology and biology. Manuscripts of lectures delivered at symposia that do not review the related field are not acceptable, nor are unevaluated compilations of the literature.