Alkalihalobacterium elongatum gen. nov. sp. nov.: An Antibiotic-Producing Bacterium Isolated From Lonar Lake and Reclassification of the Genus Alkalihalobacillus Into Seven Novel Genera.

A Gram-stain positive, long, rod-shaped, motile, and spore-forming bacterium (MEB199T) was isolated from a sediment sample collected from Lonar Lake, India. The strain was oxidase and catalase positive. The strain grew optimally at pH 10, NaCl concentration of 3.5% at 37°C. The major fatty acids were iso-C15:0, iso-C16:0, anteiso-C15:0, and iso-C17:0. The peptidoglycan contained meso-diaminopimelic acid (meso-DAP). Phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylglycerol were the major polar lipids of MEB199T. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain MEB199T belonged to the family Bacillaceae and exhibited a distinctive position among the members of the genus Alkalihalobacillus (Ahb.). Strain MEB199T shared the highest 16S rRNA gene sequence similarity with Alkalihalobacillus alkalinitrilicus ANL-iso4T (98.36%), whereas with type species Ahb. alcalophilus DSM 485T, it is 94.91%, indicating that strain MEB199T is distinctly related to the genus Alkalihalobacillus. The G + C content of genomic DNA was 36.47 mol%. The digital DNA-DNA hybridization (dDDH) (23.6%) and average nucleotide identity (ANI) (81%) values between strain MEB199T and Ahb. alkalinitrilicus ANL-iso4T confirmed the novelty of this new species. The pairwise identity based on the 16S rRNA gene sequence between the species of genus Alkalihalobacillus ranges from 87.4 to 99.81% indicating the heterogeneity in the genus. The different phylogenetic analysis based on the genome showed that the members of the genus Alkalihalobacillus separated into eight distinct clades. The intra-clade average amino acid identity (AAI) and percentage of conserved proteins (POCP) range from 52 to 68% and 37 to 59%, respectively, which are interspersed on the intra-genera cutoff values; therefore, we reassess the taxonomy of genus Alkalihalobacillus. The phenotypic analysis also corroborated the differentiation between these clades. Based on the phylogenetic analysis, genomic indices, and phenotypic traits, we propose the reclassification of the genus Alkalihalobacillus into seven new genera for which the names Alkalihalobacterium gen. nov., Halalkalibacterium gen. nov., Halalkalibacter gen. nov., Shouchella gen. nov., Pseudalkalibacillus gen. nov., Alkalicoccobacillus gen. nov., and Alkalihalophilus gen. nov. are proposed and provide an emended description of Alkalihalobacillus sensu stricto. Also, we propose the Ahb. okuhidensis as a heterotypic synonym of Alkalihalobacillus halodurans. Based on the polyphasic taxonomic analysis, strain MEB199T represents a novel species of newly proposed genus for which the name Alkalihalobacterium elongatum gen. nov. sp. nov. is proposed. The type strain is MEB199T (= MCC 2982T, = JCM 33704T, = NBRC 114256T, = CGMCC 1.17254T).

Description and genomic insights into a multidrug resistant novel bacterium Savagea serpentis sp. nov., isolated from the scats of a vine snake (Ahaetulla nasuta).

Two Gram-stain positive, endospore forming, non-motile, rod shaped bacterial strains SN6T and SN6b were isolated from scats of a mildly venomous vine snake (Ahaetulla nasuta). Strains were phenotypically resistant to multiple antibiotics of four different classes i.e. aminoglycosides, ß-lactams, fluoroquinolones and sulphonamides. Cells of both the strains were catalase positive and oxidase negative. Phylogenetic analysis based on 16S rRNA gene sequence analysis of these two strains showed closest similarity (99.2% and 99.3%) with Savagea faecisuis Con12T, the only species of the genus Savagea and ≤ 94.9% with the species of other closest genera of the family Planococcaceae. The 16S rRNA gene sequence similarity (99%), DNA-DNA relatedness (95%) and similar phenotypic characteristics between the strains SN6T and SN6b revealed their phylogenetic affiliation to the same species. Hence, strain SN6b is an additional strain of the type strain SN6T. DNA-DNA relatedness of strain SN6T with S. faecisuis Con12T was 32.8%. Predominant fatty acids were iso-C15:0 (32.0%), iso-C16:1 ω11c (19.2%) and iso-C17:1 ω10c (12.1%). MK-6 (100%) was the only respiratory quinone of strain SN6T. Diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine were the major polar lipids. Cell wall peptidoglycan was A4α; L-Lys-Gly-D-Glu type. The DNA G + C content (mol%) of SN6T was 40.8. Whole genome sequence of SN6T consisted of 26,37,389 base pairs in length with 2667 annotated genes, out of which 1021 corresponds to hypothetical proteins and 1646 with functional assignments including antibiotic resistance, multidrug resistance efflux pumps, invasion and virulence factors. Comparative polyphasic study of the strains SN6T, SN6b and S. faecisuis Con12T elucidated the differentiating characteristics which led to describing strain SN6T and SN6b as a novel species of the genus Savagea for which the name Savagea serpentis sp. nov is proposed. The type strain of Savagea serpentis is SN6T (= KCTC 33546T = CCUG 6786T).

Subsaxibacter sediminis sp. nov., isolated from Arctic glacial sediment and emended description of the genus Subsaxibacter.

A Gram-stain-negative, yellowish-orange pigmented, rod-shaped, motile bacterium, designated strain ARC111T, was isolated from sediment of Arctic permafrost at Midtre Lovénbreen glacier, Svalbard. 16S rRNA gene based identification of strain ARC111T demonstrated highest sequence similarities to Subsaxibacter broadyi P7T (97.8 %) and Subsaxibacter arcticus JCM30334T (97.5 %) and ≤95.2 % with all other members of the family Flavobacteriaceae. Phylogenetic analysis revealed the distinct positioning of strain ARC111T within the genus Subsaxibacter. The G+C content of ARC111T was 37.8±0.5 mol% while DNA-DNA hybridization depicted 35.6 % relatedness with S. arcticus JCM30334T. Strain ARC111T had C15 : 0iso, C16 : 0iso 3-OH, C15 : 1iso G, C15 : 0anteiso, C16 : 1iso H and C17 : 0iso 3-OH as major (>5 % of the total) cellular fatty acids and MK-6 was the predominant respiratory quinone. The polar lipid profile of strain ARC111T consisted of phosphatidylethanolamine, aminolipid and an unidentified lipid. Strain ARC111T harboured sym-homospermidine as the major polyamine. Characteristic differences obtained using polyphasic analysis of strain ARC111T and its closest relatives suggested that strain ARC111T is a novel species of genus Subsaxibacter, for which the name Subsaxibacter sediminis sp. nov. has been proposed. The type strain is ARC111T (=MCC 3191T=KCTC 42965T=LMG 29783T=GDMCC 1.1201T).