Cultivable bacteria represent only a fraction of the diversity in microbial communities. However, the official procedures for classification and characterization of a novel prokaryotic species still rely on isolates. Nevertheless, due to single cell genomics, it is possible to retrieve genomes from environmental samples by sequencing them individually, and to assign specific genes to a specific taxon, regardless of their ability to grow in culture. In this study, a complete description was performed for uncultured Kordia sp. TARA_039_SRF, a proposed novel species within the genus Kordia, using culture-independent techniques. The type material was a high-quality draft genome (94.97% complete, 4.65% gene redundancy) co-assembled using ten nearly identical single amplified genomes (SAGs) from surface seawater in the North Indian Ocean during the Tara Oceans Expedition. The assembly process was optimized to obtain the best possible assembly metrics and a less fragmented genome. The closest relative of the species was Kordia periserrulae, which shared 97.56% similarity of the 16S rRNA gene, 75% orthologs and 89.13% average nucleotide identity. The functional potential of the proposed novel species included proteorhodopsin, the ability to incorporate nitrate, cytochrome oxidases with high affinity for oxygen, and CAZymes that were unique features within the genus. Its abundance at different depths and size fractions was also evaluated together with its functional annotation, revealing that its putative ecological niche could be particles of phytoplanktonic origin. It could putatively attach to these particles and consume them while sinking to the deeper and oxygen depleted layers of the North Indian Ocean.

可培养细菌仅代表微生物群落多样性的一小部分。但是，用于分类和表征新型原核生物的官方程序仍然依赖于分离株。但是，由于单细胞基因组学的原因，有可能通过对环境样本进行单独测序来从其环境中检索基因组，并将特定基因分配给特定的分类单元，而不论其在培养物中的生长能力如何。在这项研究中，对未培养的Kordia sp。进行了完整的描述。TARA_039_SRF是科迪亚（ Kordia）属中的拟议新物种，使用与文化无关的技术。类型资料是在塔拉海洋考察期间，使用来自北印度洋表层海水的十个几乎相同的单个扩增基因组（SAG）共同组装的高质量草图基因组（完成了94.97％，完成了4.65％的基因冗余）。组装过程进行了优化，以获得最佳的组装指标和较少碎片的基因组。该物种的近亲是Kordia periserrulae，它们具有16S rRNA基因97.56％的相似性，75％的直向同源物和89.13％的平均核苷酸同一性。拟议的新物种的功能潜力包括蛋白视紫红质，结合硝酸盐的能力，对氧具有高亲和力的细胞色素氧化酶以及属该类独特特征的CAZymes。还评估了其在不同深度和大小分数下的丰度以及其功能注释，表明其推测的生态位可能是浮游植物起源的颗粒。它可能会附着在这些颗粒上并消耗掉它们，同时沉入北印度洋的更深层和氧气耗尽的层中。