Halalkalibacillus sediminis sp. nov., isolated from sediment of sea cucumber culture pond

Abstract

A Gram-stain-positive, rod-shaped (0.3–0.4×1.2–2.0 µm), strictly aerobic and beige-pigmented bacterium, designated B3227T, was isolated from the sediment of a sea cucumber culture pond in Rongcheng, China (122.2° E 36.9° N). Its biochemical characteristics analysis revealed that the cells of this bacterium were catalase-positive and oxidase-negative. Cell growth occurred at 15–45 °C (optimum, 37 °C), pH 6.5–9.0 (pH 7.5–8.0) and in the presence of 0.0–22.0 % (w/v) NaCl (6.0–9.0 % NaCl). Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain B3227T exhibited similarities of 95.7, 95.5, 95.5 and 95.3 % to the type strains of Filobacillus milensis , Piscibacillus salipiscarius , Halalkalibacillus halophilus and Piscibacillus halophilus , respectively, and the results of physiological analyses revealed that strain B3227T was most similar to the genus Halalkalibacillus . The cells were endospore-forming and comprised an A1-γ-meso-diaminopimelic acid-type peptidoglycan. The respiratory quinone of strain B3227T was MK-7, and the dominant fatty acids were anteiso-C15 : 0 and anteiso-C17 : 0. The major polar lipids were diphosphatidylglycerol and phosphatidylethanolamine. The genomic DNA G+C content was 38.7 mol%. The average nucleotide identity values between strain B3227T and H. halophilus JCM 14192T (ANIb 69.5%, ANIm 84.2 %) and F. milensis JCM 12288T (ANIb 70.1 %, ANIm 84.1 %) were below the cut-off level (95–96  %) for species delineation. The results of kegg analysis revealed that strain B3227T could biosynthesize shikimate acid, a base compound for the formulation of the swine flu drug. Based on its morphological and physiological properties, as well as phylogenetic distinctiveness, strain B3227T should be placed into the genus Halalkalibacillus as a representative of a new species, for which the name Halalkalibacillus sediminis sp. nov. is proposed. The type strain is B3227T (=KCTC 33093T=MCCC 1H00193T).