The phylum Planctomycetes comprises bacteria with peculiar and very unique characteristics among prokaryotes. In marine environments, macroalgae biofilms are well known for harboring planctomycetal diversity. Here, we describe a novel isolate obtained from the biofilm of the red alga Chondrus crispus collected at a rocky beach in Porto, Portugal. The novel strain LzC2^T is motile, rosette-forming with spherical- to ovoid-shaped cells. LzC2^T forms magenta- to pinkish-colored colonies in M13 and M14 media. Transmission and scanning electron microscopy observations showed a division by polar and lateral budding. Mother cells are connected to the daughter cells by a tubular neck-like structure. The strain requires salt for growth. Vitamins are not required for growth. Optimal growth occurs from 15 to 30 °C and within a pH range from 5.5 to 10.0. Major fatty acids are anteiso-C15:0 (54.2%) and iso-C15:0 (19.5%). Phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid represent the main lipids and menaquinone 6 (MK-6) is the only quinone present. 16S rRNA gene-based phylogenetic analysis supports the affiliation to the phylum Planctomycetes and family Planctomycetaceae, with Alienimonas as the closest relative. Strain LzC2^T shares 97% 16S rRNA gene sequence similarity with Alienimonas californiensis. LzC2^T has a genome size of 5.3 Mb and a G+C content of 68.3%. Genotypic and phenotypic comparison with the closest relatives strongly suggest that LzC2^T (=CECT 30038^T=LMG XXXT) is a new species of the genus Alienimonas, for which we propose the name Alienimonas chondri sp. nov., represented by LzC2^T as type strain.

16S rRNA gene accession number: GenBank = MN757873.1.

Genome accession number: GenBank = WTPX00000000.

在原核生物中，Planctomycetes门包含具有独特特征的细菌。在海洋环境中，大型藻类生物膜因具有扁平菌多样性而闻名。在这里，我们描述了一种新的分离物，该分离物是从在葡萄牙波尔图的石滩上收集的红藻软骨脆皮生物膜获得的。新型菌株LzC2 ^T是能动的，形成球状到卵形细胞的玫瑰花结。LzC2 ^T在M13和M14培养基中形成品红色至粉红色的菌落。透射电子显微镜和扫描电子显微镜的观察结果表明，芽被极性和侧芽分开。母细胞通过管状的颈状结构与子细胞相连。该菌株需要盐才能生长。增长不需要维生素。最佳生长温度为15至30°C，pH范围为5.5至10.0。主要的脂肪酸是反异-C 15：0（54.2％）和异-C 15：0（19.5％）。磷脂酰甘油，二磷脂酰甘油和未鉴定的糖脂代表主要脂质，而甲基萘醌6（MK-6）是唯一存在的醌。基于16S rRNA基因的系统发育分析支持与门菌属及其家族的隶属关系Planctomycetaceae，与Alienimonas作为最接近的亲戚。LzC2 ^T菌株与加州拟南芥具有97％的16S rRNA基因序列相似性。LzC2 ^T基因组大小为5.3 Mb，G + C含量为68.3％。基因型并与最亲近的亲属表型比较强烈建议LzC2^牛逼（= CECT 30038^牛逼= LMG XXXT）是属的一个新种Alienimonas，为此我们提出了名称Alienimonas chondri SP。11月，以LzC2 ^T代表类型菌株。

16S rRNA基因的登录号：GenBank = MN757873.1。

基因组登录号：GenBank = WTPX00000000。