Mieszkin Sophie, Pouder Eva, Uroz Stéphane, Simon-Colin Christelle, Alain Karine
Laboratoire de Microbiologie des Environnements Extrêmes LM2E, Université de Brest, CNRS, Ifremer, IUEM, Rue Dumont d'Urville, F-29280 Plouzané, France.
Centre INRAE-Grand Est-Nancy, Université de Lorraine, INRAE, UMR IAM, 54280 Champenoux, F-54000 Nancy, France.
Microorganisms. 2021 Sep 28;9(10):2053. doi: 10.3390/microorganisms9102053.
Two novel strains, HW T2.11 and HW T5.17, were isolated from decaying wood (forest of Champenoux, France). Study of the 16S rRNA sequence similarity indicated that the novel strains belong to the genus . The sequence similarity of the 16S rRNA gene of HW T2.11 with the corresponding sequences of and was 97.30% and 97.25%, while for HW T5.17 it was 96.85% and 97.14%, respectively. The DNA G+C contents of the strains were 62.32-62.50%. Cells were Gram-negative coccobacilli that had intracellular storage granules (poly-3-hydroxybutyrate (P3HB)) that confer resistance to environmental stress conditions. They were mesophilic and acidophilic organisms growing at 8-25 °C, at a pH of 2.0-6.5, and were capable of using a wide range of organic compounds and complex biopolymers such as starch, fucoidan, laminarin, pectin and cellulose, the latter two being involved in wood composition. The major cellular fatty acid was cyclo C and the major quinone was Q-10. Overall, genome relatedness indices between genomes of strains HW T2.11 and HW T5.17 (Orthologous Average Nucleotide Identity (OrthoANI) value = 83.73% and digital DNA-DNA hybridization score = 27.5%) confirmed that they belonged to two different species. Genetic predictions indicate that the cyclopropane fatty acid (CFA) pathway is present, conferring acid-resistance properties to the cells. The two novel strains might possess a class IV polyhydroxyalcanoate (PHA) synthase operon involved in the P3HB production pathway. Overall, the polyphasic taxonomic analysis shows that these two novel strains are adapted to harsh environments such as decaying wood where the organic matter is difficult to access, and can contribute to the degradation of dead wood. These strains represent novel species of the genus , for which the names sp. nov. and sp. nov. are proposed. The type strains of and are, respectively, HW T2.11 (DSM 111006; UBOCC-M-3364) and HW T5.17 (DSM 111007; UBOCC-M-3365).
从腐烂木材（法国尚波努森林）中分离出了两株新菌株，HW T2.11和HW T5.17。16S rRNA序列相似性研究表明，这两株新菌株属于[未提及的属名]属。HW T2.11的16S rRNA基因与[未提及的两个属名]相应序列的相似性分别为97.30%和97.25%，而HW T5.17的相似性分别为96.85%和97.14%。这些菌株的DNA G+C含量为62.32 - 62.50%。细胞为革兰氏阴性球杆菌，具有细胞内储存颗粒（聚-3-羟基丁酸酯（P3HB）），可赋予对环境胁迫条件的抗性。它们是嗜温嗜酸生物，在8 - 25°C、pH值为2.0 - 6.5的条件下生长，能够利用多种有机化合物和复杂生物聚合物，如淀粉、岩藻依聚糖、海带多糖、果胶和纤维素，后两者参与木材组成。主要细胞脂肪酸为环丙烷脂肪酸C，主要醌为Q - 10。总体而言，菌株HW T2.11和HW T5.17基因组之间的基因组相关性指数（直系同源平均核苷酸同一性（OrthoANI）值 = 83.73%，数字DNA - DNA杂交得分 = 27.5%）证实它们属于两个不同的物种。遗传预测表明存在环丙烷脂肪酸（CFA）途径，赋予细胞抗酸特性。这两株新菌株可能拥有参与P3HB生产途径的IV类聚羟基烷酸酯（PHA）合酶操纵子。总体而言，多相分类分析表明，这两株新菌株适应于诸如腐烂木材等难以获取有机物质的恶劣环境，并可促进枯木的降解。这些菌株代表了[未提及的属名]属的新物种，为此提出了[未提及的两个新物种名] sp. nov.和[未提及的两个新物种名] sp. nov.。[未提及的两个新物种名]的模式菌株分别为HW T2.11（DSM 111006；UBOCC - M - 3364）和HW T5.17（DSM 111007；UBOCC - M - 3365）。
