Achromobacter aestuarii sp. nov., Isolated from an Estuary.

A novel strain KS-M25T was isolated from estuary water in South Korea. Strain KS-M25T was Gram-staining-negative, strictly aerobic, motile rods-shaped bacterium and showed oxidase- and catalase-positive reactions. Growth of strain KS-M25T was observed at 10-25 °C (optimum, 20 °C), at pH 5.5-9.0 (optimum, pH 7.5), and with 0-6.0% (w/v) NaCl (optimum, 1%). Ubiquinone-8 was identified as the sole isoprenoid quinone and the major fatty acids were C16:0, cyclo-C17:0 and sum in feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c). The G+C content values based on genome sequences was 62.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KS-M25T formed a clear cluster within the genus Achromobacter. Strain KS-M25T was most closely related to Achromobacter anxifer LMG 26857T, Achromobacter dolens LMG 26840T, and Achromobacter xylosoxidans NBRC 15126T with 97.8%, 97.8%, and 97.7% 16S rRNA gene sequence similarities, respectively. Based on phenotypic, chemotaxonomic, and phylogenetic analysis, strain KS-M25T represents a novel species of the genes Achromobacter, for which the name Achromobacter aestuarii sp. nov. is proposed. The type strain is KS-M25T (= KACC 21219T = JCM 33329T).

The Taxonomy and Diversity of Proschkinia (Bacillariophyta), A Common But Enigmatic Genus from Marine Coasts.

Detailed morphological documentation is provided for established Proschkinia taxa, including the generitype, P. bulnheimii, and P. complanata, P. complanatula, P. complanatoides and P. hyalosirella, and six new species. All established taxa are characterized from original material from historical collections. The new species described in this paper (P. luticola, P. staurospeciosa, P. impar, P. modesta, P. fistulispectabilis, and P. rosowskii) were isolated from the Western Pacific (Yellow Sea coast of Korea) and the Atlantic (Scottish and Texas coasts). Thorough documentation of the frustule, valve and protoplast architecture revealed the combination of characters diagnostic of the genus Proschkinia: a single-lobed chloroplast; a broad girdle composed of U-shaped, perforated bands; the position of the conopeate raphe-sternum relative to the external and internal valve surface; and the presence of an occluded process through the valve, termed the "fistula". Seven strains of Proschkinia were grown in culture and five of these were sequenced for nuclear ribosomal SSU and plastid-encoded rbcL. Phylogenetic analysis recovered a clade of Proschkinia with Fistulifera, another fistula-bearing diatom genus, and together these were sister to a clade formed of the Stauroneidaceae; in turn, all of these were sister to a clade composed of Parlibellus and two monoraphid genera Astartiella and Schizostauron. Despite morphological similarities between Proschkinia and the Naviculaceae, these two taxa are distant in our analysis. We document the variation in the morphology of Proschkinia, including significant variability in the fistula, suggesting that fistula ultrastructure might be one of the key features for species identification within the genus.