The species of the genus ''Aquabacterium'' are motile,

rod-shaped A bacillus (), also called a bacilliform bacterium or often just a rod (when the context makes the sense clear), is a rod-shaped bacterium or archaeon. Bacilli are found in many different taxonomic groups of bacteria. However, the name ''Bacillu ...

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

oxidase In biochemistry, an oxidase is an enzyme that catalyzes oxidation-reduction reactions, especially one involving dioxygen (O2) as the electron acceptor. In reactions involving donation of a hydrogen atom, oxygen is reduced to water (H2O) or hydro ...

-positive,

catalase Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in protecting t ...

-negative

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

which were isolated from drinking water biofilms in Berlin. Identified species include '' Aquabacterium citratiphilum'', '' Aquabacterium parvum'', and '' Aquabacterium commune''. Three bacterial strains isolated from biofilms of the Berlin drinking water system were characterized with respect to their morphological and physiological properties and their taxonomic position. Phenotypically, the bacteria investigated were motile, Gram-negative rods, oxidase-positive and catalase-negative, and contained polyalkanoates and polyphosphate as storage polymers. They displayed a microaerophilic growth behaviour and used oxygen and nitrate as electron acceptors, but not nitrite, chlorate, sulfate, or ferric iron. The substrates metabolized included a broad range of organic acids, but no carbohydrates at all. The three species can be distinguished from each other by their substrate use, ability to hydrolyse urea and casein, cellular protein patterns, and growth on nutrient-rich media, as well as their temperature, pH, and NaCl tolerances. Phylogenetic analysis, based on 16S rRNA gene sequence comparison, revealed that the isolates are affiliated to the beta 1-subclass of Proteobacteria. The isolates constitute three new species with internal levels of DNA relatedness ranging from 44.9 to 51.3%. It is proposed that a new genus, ''Aquabacterium'' gen. nov., should be created, including ''Aquabacterium citratiphilum'' sp. nov.,'' Aquabacterium parvum'' sp. nov., and ''Aquabacterium commune'' sp. nov. The type species of the new genus is ''Aquabacterium commune''.

References

Bacteria genera Comamonadaceae {{betaproteobacteria-stub