Department of Applied Biology, KIT Karlsruhe, Germany.
Department of Microbiology, Albert-Ludwigs University Freiburg, Germany.
Int J Syst Evol Microbiol. 2013 Apr;63(Pt 4):1499-1504. doi: 10.1099/ijs.0.042986-0. Epub 2012 Aug 3.
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)).
一株革兰氏阴性、非运动性、兼性厌氧、耐酸的杆状菌，被命名为 DKE6(T) 菌株，从德国 Drei Kronen und Ehrt 硫矿的酸性生物膜（pH 值 2.5）中分离得到。该分离株在 pH 值为 5.5 时生长最佳，在 25 到 30°C 之间生长，仅以酪蛋白作为碳源和能源；尽管测试了多种糖作为生长底物，但没有一种能够支持该分离株的生长。在酪蛋白消耗过程中，DKE6(T) 菌株产生铵，导致培养基碱化。这可能是一种提高细胞附近 pH 值并因此调节 pH 值向生长最佳值的策略。优势脂肪酸（>5%）为 iso-C11:0 3-OH、iso-C15:0、iso-C17:0 和 iso-C17:1ω9c。DNA G+C 含量为 66.6%。DKE6(T) 菌株不能氧化铁或硫代硫酸盐。检测到铁还原。该分离株与最密切相关的可培养菌株 Dokdonella koreensis DS-123(T) 的 16S rRNA 基因序列相似度为 93.3%，但与其他密切相关的γ变形菌型种的模式菌株的相似度<93.2%。基于生理生化数据，该分离株被认为代表了γ变形菌纲中一个新属的新种，我们建议将其命名为 Metallibacterium scheffleri 属。新模式种的模式株为 DKE6(T)（=DSM 24874(T)=JCM 17596(T)）。
