Cystobacter

Abstract

Cys.to.bac' ter . Gr. fem. n. kystis bladder; M.L. masc. n. bacter from Gr. fem. n. bakteria rod, stick; M.L. masc. n. Cystobacter bladder‐forming rod. Proteobacteria / Deltaproteobacteria / Myxococcales / Cystobacteraceae / Cystobacter The history of the genus Cystobacter and the problems associated with its recognition are discussed above in the introduction to the family. The fruiting body shape and structure of Cystobacter is similar to fruiting bodies produced by Polyangium, Sorangium, Byssophaga, Jahnia, Pyxicoccus , and to a certain extent, Stigmatella hybrida . The genus as it is presented here still is heterogeneous and probably comprises at least three different genera. One group of species, with Cystobacter fuscus as the main representative, has slender, often slightly C‐ or S‐shaped bent, rod‐shaped myxospores with more or less tapering ends. Many strains of this group are efficient chitin degraders. The second group, represented by Cystobacter disciformis , has myxospores that are stout, short, fat rods, very much like myxospores of Archangium gephyra . These organisms rarely attack chitin. A third group, centered around Cystobacter gracilis , has delicate vegetative cells with tapering ends, and small myxospores that are straight or slightly bent rods with rounded ends. Analysis of the available 16S rRNA sequences separates at least the first two groups rather neatly (Spröer et al., 1999). Type species : Cystobacter fuscus Schroeter 1886, 170.