Recommendations for revision of the taxonomic treatment of stalked bacteria

Abstract

During the past few years, observations on stalked bacteria have been reported that permit a meaningful reevaluation of their taxonomic treatment. We recommend here that two families of stalked bacteria be recognized: Caulobacteraceae, to comprise bacteria whose stalk is an integral part of the cell, and Gallionellaceae, to comprise bacteria whose stalk is a secreted structure. Two genera should be included in Caulobacteraceae, viz., Caulobacter Henrici and Johnson and Asticcacaulis Poindexter. A single genus, Gallionella Ehrenberg, should be included in Gallionellaceae. The genera Siderophacus and Nevskia should not be included in either family, since cultivated cells of these genera have not yet been studied; their affinity to Gallionellaceae is acknowledged.