Agrococcus sediminis sp. nov., an actinobacterium isolated from lake sediment.

A novel strain, designated NS18T, was isolated from sediment sampled at Taihu Lake, PR China. Cells of the isolate were spherical, aerobic, non-motile, Gram-stain-positive and non-endospore-forming. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NS18T clustered in a clade of the genus Agrococcus. Its closest phylogenetic neighbour was Agrococcus lahaulensis DSM 17612T with 98.2 % 16S rRNA gene sequence similarity. The complete genome of NS18T was 2 736 037 bp and its genomic DNA G+C content was 72.8 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain NS18T and A. lahaulensis DSM 17612T based on their whole genomes were 85.1 and 28.7 %, respectively. The major fatty acids were anteiso-C17 : 0 and anteiso-C15 : 0. The predominant menaquinones were MK11 and MK12. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol and two unidentified lipids. The components of the peptidoglycan were Ala, Gly, Asp, Thr and DAB. The whole-cell sugars contained rhamnose, ribose, xylose and glucose. According to the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain NS18T (=NBRC 113859T=MCCC 1K03759T) represents a novel species, for which the name Agrococcus sediminis sp. nov is proposed.

Dyadobacter flavalbus sp. nov., isolated from lake sediment.

A novel bacterial strain, designated NS28T, was isolated from interfacial sediment sampled at Taihu Lake, PR China. Cells were rod-shaped, Gram-negative, aerobic and non-motile on Reasoner's 2A medium. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NS28T was most closely related to species from the genus Dyadobacter, with 98.4 and 96.0 % 16S rRNA gene sequence similarity to its closest phylogenetic neighbours Dyadobacter sediminis CGMCC 1.12895T and Dyadobacter luticola CCTCC AB 2017091T, respectively. MK-7 was the only cellular menaquinone. The major fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and C16 : 1ω5c. The major polar lipids were phosphatidylethanolamine, one phospholipid, one aminolipid, one lipid and two unidentified lipids. Genomic analysis of strain NS28T indicated that the total genome size was 6 477 094 bp with a G+C content of 44.8 mol%, 5380 protein-coding genes, 79 contigs and an N50 length of 299584 bp. On the basis of the genomic DNA sequence, the average nucleotide identity values were 90.5 and 74.1 % with D. sediminis CGMCC 1.12895T and D. luticola CCTCC AB 2017091T, respectively. Digital DNA-DNA hybridization results of strain NS28T with D. sediminis CGMCC 1.12895T and D. luticola CCTCC AB 2017091T were 40.9 and 18.6 %, respectively. Based on the phenotypic, chemotaxonomic, phylogenetic and genome sequence data presented here, it is proposed that strain NS28T represents a novel species of the genus Dyadobacter for which the name Dyadobacter flavalbus is proposed . The type strain is NS28T (=NBRC 113854T=MCCC 1K03764T).

Description of Ornithinibacillus gellani sp. nov., a halophilic bacterium isolated from lake sediment, and emended description of the genus Ornithinibacillus.

A Gram-stain-positive, strictly aerobic, motile and rod-shaped bacterium, designated strain LJ137T, was isolated from the sediment of Taihu Lake in China. A polyphasic approach was used to investigate its taxonomic position. Strain LJ137T grew optimally at pH 7.5, at 37 °C and with 2.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain LJ137T was most closely related to the genera Ornithinibacillus and Oceanobacillus. The closest phylogenetic neighbours were Ornithinibacillus halophilus KCTC 13822T, Ornithinibacillus salinisoli LCB256T and Oceanobacillus limi KCTC 13823T, with 95.2, 96.5 and 95.6 % 16S rRNA gene sequence similarity, respectively. The peptidoglycan amino acid type was A4α (l-Lys-d-Asp). The major respiratory quinone was menaquinone-7 (MK-7). The polar lipids of strain LJ137T contained diphosphatidylglycerol, phosphatidylglycerol, three unidentified phospholipids, two aminophospholipids and one unidentified lipid. The G+C content of the genomic DNA was 40.4 mol%. The dominant cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C15 : 0. Based on the phenotypic, chemotaxonomic, phylogenetic and genome sequence characteristics of this strain, a novel species, Ornithinibacillus gellani sp. nov., is proposed. The type strain is LJ137T (=CGMCC 1.13678T=NBRC 113552T). An emended description of the genus Ornithinibacillus is presented.