Lysinibacillus antri sp. nov., isolated from cave soil.

A Gram-stain-positive, motile, rod-shaped and endospore-forming strain, SYSU K30002T, was isolated from a soil sample collected from a karst cave in Xingyi county, Guizhou province, south-west China. SYSU K30002T grew at 28-40 °C (optimum, 37 °C), at pH 5.0-8.0 (optimum, pH 7.0) and in the presence of 0-4 % (w/v) NaCl (optimum in the absence of NaCl). The cell-wall peptidoglycan type was A4α (Lys-Asp). The cell-wall sugars of SYSU K30002T were ribose, galactose and mannose, and MK-7 was the menaquinone. The major fatty acids were iso-C15 : 0, C16 : 1 ω7c alcohol and iso-C16 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unidentified phospholipids. The G+C content of the genomic DNA was 36.1 mol%. The average nucleotide identity values between SYSU K30002T and its closest relatives were below the cut-off level (95-96 %) for species delineation. Based on phenotypic, chemotaxonomic and genome comparisons, strain SYSU K30002T represents a novel species of the genus Lysinibacillus, for which the name Lysinibacillusantri sp. nov. is proposed. The type strain is SYSU K30002T (=KCTC 33955T=CGMCC 1.13504T).

Vulcaniibacterium gelatinicum sp. nov., a moderately thermophilic bacterium isolated from a hot spring.

The present study aimed to determine the taxonomic positions of strains designated R-5-52-3T, R-5-33-5-1-2, R-5-48-2 and R-5-51-4 isolated from hot spring water samples. Cells of these strains were Gram-stain-negative, non-motile and rod-shaped. The strains shared highest 16S rRNA gene sequence similarity with Vulcaniibacterium thermophilum KCTC 32020T (95.1%). Growth occurred at 28-55 °C, at pH 6-8 and with up to 3 % (w/v) NaCl. DNA fingerprinting, biochemical, phylogenetic and 16S rRNA gene sequence analyses suggested that R-5-52-3T, R-5-33-5-1-2, R-5-48-2 and R-5-51-4 were different strains but belonged to the same species. Hence, R-5-52-3T was chosen for further analysis and R-5-33-5-1-2, R-5-48-2 and R-5-51-4 were considered as additional strains of this species. R-5-52-3T possessed Q-8 as the only quinone and iso-C15:0, iso-C11:0, C16 : 0 and iso-C17 : 0 as major fatty acids. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified polar lipids and two unidentified phospholipids. The genomic G+C content was 71.6 mol%. Heat shock proteins (e.g. Hsp20, GroEL, DnaK and Clp ATPases) were noted in the R-5-52-3T genome, which could suggest its protection in the hot spring environment. Pan-genome analysis showed the number of singleton gene clusters among Vulcaniibacterium members varied. Average nucleotide identity (ANI) values between R-5-52-3T, Vulcaniibacterium tengchongense YIM 77520T and V. thermophilum KCTC 32020T were 80.1-85.8 %, which were below the cut-off level (95-96 %) recommended as the ANI criterion for interspecies identity. Thus, based on the above results, strain R-5-52-3T represents a novel species of the genus Vulcaniibacterium, for which the name Vulcaniibacterium gelatinicum sp. nov. is proposed. The type strain is R-5-52-3T (=KCTC 72061T=CGMCC 1.16678T).

Lysinibacillus cavernae sp. nov., isolated from cave soil.

A Gram-staining positive, motile, rod-shaped and subterminal endospore-forming bacterium, designated strain SYSU K30005T, was isolated from a soil sample collected from a karst cave in Libo county, Guizhou province, south-western China. Strain SYSU K30005T showed the highest 16S rRNA gene sequence similarity with Lysinibacillus fusiformis (98.6%) and Lysinibacillus sphaericus (98.2%). In phylogenetic tree, strain SYSU K30005T clade with the members of the genus Lysinibacillus. Based on the phylogenetic and 16S gene sequence result, strain SYSU K30005T was affiliated to the genus Lysinibacillus. The growth of SYSU K30005T was observed at 15-37 °C (optimum, 28 °C), pH 6.0-9.0 (optimum, pH 7.0) and in the presence of 0-4% (w/v) NaCl (optimum in 3.5% NaCl). Cell wall peptidoglycan type was A4α (Lys-Asp). The cell-wall sugars of SYSU K30005T were ribose, galactose and mannose and MK-7 was the only quinone. The fatty acids (> 5% of total fatty acids) were iso-C15:0, anteiso-C15:0, iso-C16:0 and iso-C17:0. The polar lipids profile included diphosphatidylglycerol, phosphatideylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The genomic DNA G + C content was 37.2 mol%. The average nucleotide identity values between SYSU K30005T and its closest relatives were below the cut-off level (95-96%) for species delineation. The results support the conclusion that strain SYSU K30005T represents a novel species of the genus Lysinibacillus, for which we proposed the name Lysinibacillus cavernae sp. nov. The type strain is SYSU K30005T (= KCTC 43130T = CGMCC 1.17492T).

Bacillus antri sp. nov., isolated from cave soil.

A Gram-stain-positive, strictly aerobic, rod-shaped, motile, endospore-forming strain, SYSU K30001T, was isolated from a soil sample collected from a cave in Xingyi county, Guizhou province, south-west China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU K30001T belonged to the genus Bacillus, with the highest sequence similarity to the type strain of Bacillus panaciterrae (98.1 %). Growth occurred at pH 6.0-9.0 (optimum, pH 7.0), at 28-55 °C (optimum, 28 °C) and in the presence of 0-3 % (w/v) NaCl (optimum in the absence of NaCl). Strain SYSU K30001T contained meso-2,6-diaminopimelic acid in the cell-wall peptidoglycan and MK-7 as the only isoprenoid quinone present. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified glycolipid. The major fatty acids were iso-C15 : 0, iso-C17 : 1ω10c, anteiso-C14 : 0 and iso-C17 : 0. The genome G+C content was 39.8 mol%. The average nucleotide identity values between SYSU K30001T and B. panaciterrae DSM 19096T were 72.1 % (ANIb) and 83.1 % (ANIm), which were below the cut-off level (95-96 %) for species delineation. Based on phenotypic, chemotaxonomic and molecular characterizations, strain SYSU K30001T represents a novel species of the genus Bacillus, for which the name Bacillus antri sp. nov. is proposed. The type strain is SYSU K30001T (=KCTC 33954T=CGMCC 1.13871T).