Planctomycetes are ubiquitous bacteria with environmental and biotechnological relevance. Axenic cultures of planctomycetal strains are the basis to analyse their unusual biology and largely uncharacterised metabolism in more detail. Here, we describe strain Mal4^T isolated from marine sediments close to Palma de Mallorca, Spain. Strain Mal4^T displays common planctomycetal features, such as division by polar budding and the presence of fimbriae and crateriform structures on the cell surface. Cell growth was observed at ranges of 10–39 °C (optimum at 31 °C) and pH 6.5–9.0 (optimum at 7.5). The novel strain shows as pear-shaped cells of 2.0 ± 0.2 × 1.4 ± 0.1 µm and is one of the rare examples of orange colony-forming Planctomycetes. Its genome has a size of 7.7 Mb with a G+C content of 63.4%. Phylogenetically, we conclude that strain Mal4^T (= DSM 100296^T= LMG 29133^T) is the type strain representing the type species of a novel genus, for which we propose the name Maioricimonas rarisocia gen. nov., sp. nov.

Planctomycetes 是普遍存在的细菌，与环境和生物技术相关。扁平菌菌株的无菌培养是更详细地分析其不寻常的生物学和很大程度上未表征的代谢的基础。在这里，我们描述了从靠近西班牙马略卡岛帕尔马的海洋沉积物中分离出来的Mal4 ^T菌株。应变 Mal4 ^T显示常见的浮游菌特征，例如通过极地出芽分裂以及细胞表面存在菌毛和火山口状结构。在 10–39 °C（最佳温度为 31 °C）和 pH 6.5–9.0（最佳温度为 7.5）的范围内观察到细胞生长。新菌株显示为 2.0 ± 0.2 × 1.4 ± 0.1 µm 的梨形细胞，是形成橙色菌落的浮游菌的罕见例子之一。其基因组大小为 7.7 Mb，G+C 含量为 63.4%。在系统发育上，我们得出结论，菌株 Mal4 ^T (= DSM 100296 ^T = LMG 29133 ^T ) 是代表新属的模式种的模式菌株，为此我们建议将其命名为Maioricimonas rarisocicia gen。十一月，sp。十一月