Bacteria of the genus Massilia often colonize extreme ecosystems, however, a detailed study of the massilias from the Antarctic environment has not yet been performed. Here, sixty-four Gram-stain-negative, aerobic, motile rods isolated from different environmental samples on James Ross Island (Antarctica) were subjected to a polyphasic taxonomic study. The psychrophilic isolates exhibited slowly growing, moderately slimy colonies revealing bold pink-red pigmentation on R2A agar. The set of strains exhibited the highest 16S rRNA gene sequence similarities (99.5–99.9%) to Massilia violaceinigra B2^T and Massilia atriviolacea SOD^T and formed several phylogenetic groups based on the analysis of gyrB and lepA genes. Phenotypic characteristics allowed four of them to be distinguished from each other and from their closest relatives. Compared to the nearest phylogenetic neighbours the set of six genome-sequenced representatives exhibited considerable phylogenetic distance at the whole-genome level. Bioinformatic analysis of the genomic sequences revealed a high number of putative genes involved in oxidative stress response, heavy-metal resistance, bacteriocin production, the presence of putative genes involved in nitrogen metabolism and auxin biosynthesis. The identification of putative genes encoding aromatic dioxygenases suggests the biotechnology potential of the strains. Based on these results four novel species and one genomospecies of the genus Massilia are described and named Massilia rubra sp. nov. (P3094^T = CCM 8692^T = LMG 31213^T), Massilia aquatica sp. nov. (P3165^T = CCM 8693^T = LMG 31211^T), Massilia mucilaginosa sp. nov. (P5902^T = CCM 8733^T = LMG 31210^T), and Massilia frigida sp. nov. (P5534^T = CCM 8695^T = LMG 31212^T).

Massilia属的细菌通常定居在极端的生态系统中，但是，尚未对南极环境中的Massilias进行详细研究。在这里，对从詹姆斯·罗斯岛（南极洲）的不同环境样品中分离出的64克革兰氏阴性，好氧，能动杆进行了多相分类学研究。嗜冷菌分离株显示出缓慢生长的中等粘液菌落，在R2A琼脂上显示出大胆的粉红色色素沉着。该组菌株显示出最高的16S rRNA基因序列的相似性（99.5-99.9％），以马西利亚violaceinigra B2 ^Ť和马西利亚atriviolacea SOD ^Ť和形成了几个系统发育组基于所述分析的gyrB和lepA基因。表型特征使它们中的四个与彼此的近亲区别开来。与最近的系统发育邻居相比，这六个基因组测序的代表在全基因组水平上展现出可观的系统发育距离。对基因组序列的生物信息学分析显示，氧化应激反应，重金属抗性，细菌素产生涉及大量推定基因，氮代谢和生长素生物合成涉及推定基因。推定的编码芳香族双加氧酶的基因的鉴定表明了该菌株的生物技术潜力。根据这些结果，马西利亚属的四个新物种和一个属被描述并命名为Massilia rubra sp。十一月 （P3094 ^T  = CCM 8692 ^T  = LMG 31213 ^T），Massilia aquatica sp。十一月 （P3165 ^T  = CCM 8693 ^T  = LMG 31211 ^T），Massilia mucilaginosa sp。十一月 （P5902 ^T  = CCM 8733 ^T  = LMG 31210 ^T）和Massilia frigida sp。十一月 （P5534 ^T  = CCM 8695 ^T  = LMG 31212 ^T）。