title: Metallibacterium scheffleri gen. nov., sp. nov., an alkalinizing gammaproteobacterium isolated from an acidic biofilm.
abstract: A Gram-stain-negative, non-motile, facultatively anaerobic, acid-tolerant rod, designated strain DKE6(T), was isolated from an acidic biofilm (pH 2.5) harvested in the pyrite mine Drei Kronen und Ehrt in Germany. The isolate grew optimally at pH 5.5, between 25 and 30 °C and only with casein as the carbon and energy source; although a variety of sugars were tested as growth substrates, none supported growth of the isolate. During casein consumption, strain DKE6(T) produced ammonium, which led to an alkalinization of the medium. This is a possible strategy to raise the pH in the direct vicinity of the cell and hence modulate the pH towards the growth optimum. The predominant fatty acids (>5 %) were iso-C11 : 0 3-OH, iso-C15 : 0, iso-C17 : 0 and iso-C17 : 1ω9c. The DNA G+C content was 66.6 %. Strain DKE6(T) was not able to oxidize iron or thiosulfate. Iron reduction was detected. The isolate showed 93.3 % 16S rRNA gene sequence similarity to the most closely related cultivable strain, Dokdonella koreensis DS-123(T), but <93.2 % sequence similarity with other type strains of closely related type species of the Gammaproteobacteria. On the basis of physiological and biochemical data, the isolate is considered to represent a novel species of a new genus in the class Gammaproteobacteria, for which we propose the name Metallibacterium scheffleri gen. nov., sp. nov. The type strain of the type species is DKE6(T) ( = DSM 24874(T) = JCM 17596(T)).
authors.affiliation: Department of Applied Biology, KIT Karlsruhe, Germany.|Department of Microbiology, Albert-Ludwigs University Freiburg, Germany.
authors.forename: Sibylle
authors.initials: S
authors.lastname: Ziegler
authors.affiliation: Department of Medical Microbiology and Hygiene, University Hospital Freiburg, Germany.|Department of Microbiology, Albert-Ludwigs University Freiburg, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Waidner
authors.affiliation: Department of Microbiology, Albert-Ludwigs University Freiburg, Germany.
authors.forename: Takashi
authors.initials: T
authors.lastname: Itoh
authors.affiliation: Japan Collection of Microorganisms, RIKEN BioResource Center, Wako, Japan.
authors.forename: Peter
authors.initials: P
authors.lastname: Schumann
authors.affiliation: Japan Collection of Microorganisms, RIKEN BioResource Center, Wako, Japan.
authors.forename: Stefan
authors.initials: S
authors.lastname: Spring
authors.affiliation: Department of Applied Biology, KIT Karlsruhe, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Gescher
mesh_terms: D015373:Bacterial Typing Techniques; D001482:Base Composition; D018441:Biofilms; D003580:Cytochromes / Q000032:analysis; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D005858:Germany; D007501:Iron; D008906:Mining; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013440:Sulfides; D014451:Ubiquinone / Q000032:analysis; D044166:Xanthomonadaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D003580:Cytochromes; D004269:DNA, Bacterial; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S; D013440:Sulfides; C011342:pyrite; D014451:Ubiquinone; C030778:ubiquinone 8; D007501:Iron