Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia.
Institute of Biochemistry and Physiology of Microorganisms, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Moscow Region, 142290, Pushchino, Russia.
Antonie Van Leeuwenhoek. 2022 Oct;115(10):1253-1264. doi: 10.1007/s10482-022-01769-x. Epub 2022 Aug 14.
Planctomycetes of the family Pirellulaceae are commonly addressed as budding aquatic bacteria with a complex lifestyle. Although this family is well represented by cultured and taxonomically characterized isolates, nearly all of them were obtained from brackish or marine habitats. The examples of described freshwater Pirellulaceae planctomycetes are limited to two species only, Pirellula staley and 'Anatilimnocola aggregata'. In this study, we characterized a novel freshwater planctomycete of the genus 'Anatilimnocola', strain PX40, which was isolated from a boreal eutrophic lake. Strain PX40 was represented by budding, unpigmented, ellipsoidal to pear-shaped cells, which often occurred in characteristic flower-like rosettes. Cells were covered by bundles of fimbriae; crateriform-like structures were localized on a reproductive cell pole only. These planctomycetes were obligately aerobic, heterotrophic bacteria that utilized various sugars and some polysaccharides, and were highly sensitive to NaCl. Growth occurred in the pH range 5.0-7.5 (with an optimum at pH 6.5-7.0), and at temperatures between 15 and 30 °C (with an optimum at 22-25 °C). The major fatty acids of strain PX40 were C18:1ω9c, C16:0, and 16:1ω7c; cells also contained a wide variety of hydroxy- and dihydroxy-fatty acids and a C31:9 alkene. The major intact polar lipids were diacylglyceryl-(N,N,N)-trimethylhomoserines. The 16S rRNA gene sequence of strain PX40 displayed 96.6% similarity to that of 'Anatilimnocola aggregata' ETA_A8. The genome of strain PX40 was 8.93 Mb in size and contained one copy of rRNA operon, 76 tRNA genes and 7092 potential protein-coding genes. The DNA G+C content was 57.8%. The ANI value between strain PX40 and 'Anatilimnocola aggregata' ETA_A8 was 78.3%, suggesting that these planctomycetes represent distinct species. We, therefore, propose a novel species of the genus 'Anatilimnocola', 'A. floriformis' sp. nov., with strain PX40 (= KCTC 92369 = VKM B-3621 = UQM 41463) as the type strain.
PX40 是一株分离自北方富营养化湖泊的新型淡水浮霉状菌属（Anatilimnocola）浮游菌，属于 Pirellulaceae 科。PX40 由出芽、无色、椭圆形到梨形的细胞组成，这些细胞常呈特征性的花状轮生。细胞被束状菌毛覆盖；仅在生殖细胞极上有坑状结构。这些浮霉状菌是专性需氧异养细菌，能够利用各种糖和一些多糖，对 NaCl 高度敏感。生长的 pH 值范围为 5.0-7.5（最佳 pH 值为 6.5-7.0），温度范围为 15-30°C（最佳温度为 22-25°C）。PX40 菌株的主要脂肪酸为 C18:1ω9c、C16:0 和 16:1ω7c；细胞还含有多种羟基和二羟基脂肪酸以及 C31:9 链烯。主要完整极性脂类是双酰基甘油-(N,N,N)-三甲基高丝氨酸。菌株 PX40 的 16S rRNA 基因序列与 'Anatilimnocola aggregata' ETA_A8 的相似度为 96.6%。PX40 菌株的基因组大小为 8.93 Mb，包含一个 rRNA 操纵子、76 个 tRNA 基因和 7092 个潜在的蛋白质编码基因。DNA G+C 含量为 57.8%。菌株 PX40 与 'Anatilimnocola aggregata' ETA_A8 之间的 ANI 值为 78.3%，表明这些浮霉状菌代表不同的种。因此，我们提出了一个新的浮霉状菌属物种，命名为 'A. floriformis' sp. nov.，以 PX40 菌株（= KCTC 92369 = VKM B-3621 = UQM 41463）为模式菌株。
