Abstract

Two Gram-positive, rod-shaped, motile, endospore-forming strains, SYSU K30003(T) and SYSU K30004(T), were isolated from cave soil sampled in Xingyi County, Guizhou Province, south-west PR China. The 16S rRNA gene sequence results indicated that strains SYSU K30003(T) and SYSU K30004(T) had highest sequence similarities to Paenibacillus thermoaerophilus DSM 26310(T) (93.2%) and Paenibacillus haemerocallicola KCTC 33185(T) (97.8%), respectively. Optimum growth for both strains occurred at pH 7.0 and 37 degrees C. Both strains contained meso-2,6-diaminopimelic acid in their cell-wall peptidoglycan and MK-7 was the only isoprenoid quinone detected. The polar lipid profile of strain SYSU K30004(T) consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two aminophospholipids. an unidentified glycolipid, unidentified phospholipids and two unidentified polar lipids. The polar lipid profile of strain SYSU K30003(T) contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unidentified glycolipid. The major fatty acids (>5%) of strain SYSU K30003(T) were anteiso-C-15:0, C-16:0, anteiso-C-17:0, and iso-C-16:0 while those of strain SYSU K30004(T) anteiso-C-15:0, C-16:0, anteiso-C-17:0, iso-C-15:0, iso-C-16:0 and iso-C-17:0. The genome G+C contents of strains SYSU K30003(T) and SYSU K30004(T) were 59.0 and 53.6 mol%, respectively. The average nucleotide identity values between strains SYSU K30003(T) and SYSU K30004(T) and other closely related Paenibacillus members were below the cut-off level (95-96%) for species identification. Based on the results of phenotypic, chemotaxonomic and genome analyses, strains SYSU K30003(T) and SYSU K30004(T) represent two novel species of the genus Paenibacillus, for which the names Paenibacillus antri sp. nov. and Paenibacillus mesophilus sp. nov. are proposed. The type strains are SYSU K30003(T) (=KCTC 33956(T)=CGMCC 1.13505(T)) and SYSU K30004(T) (=KCTC 33957(T) =CGMCC 1.13872(T)).