Lachnoanaerobaculum gingivalis sp. nov., Isolated from Human Subgingival Dental Plaque

Objectives: A novel Gram-stain-negative, obligately anaerobic, spore-forming rod, designated strain ChDC B114^T, was isolated from a human dental plaque of gingivitis lesion. The purpose of this study was to classifiy the strain at the species level.
Methods: The strain was characterized by polyphasic taxonomic analysis including 16S ribosomal RNA gene (16S rDNA) analysis and physiological and chemotaxonomic characterizations to identify it at the species level.
Results: The 16S rDNA sequence analysis revealed that the strain belongs to the genus Lachnoanaerobaculum. Percent similarity of 16S rDNA of the strain was most closed to that of Lachnoanaerobaculum orale N1^T (98.5%) and Lachnoanaerobaculum saburreum CCUG 28089^T (97.6%). The prevalent fatty acids of strain ChDC B114^T were C_16:0 (30.66%), C_14:0 (17.74%), iso-C_19:0 (14.94%), and C_17:0 2OH (12.01%). The draft genome of strain ChDC B114^T was 3,097,953 bp in length. The G + C content of the strain was 35.9 mol%. Average nucleotide identity values between strain ChDC B114^T and L. orale N1^T or L. saburreum CCUG 28089^T was 83.2% and 82.0%. Genome-to-genome distance values between strain ChDC B114^T and L. orale N1^T or L. saburreum CCUG 28089^T were 26.8% (24.5-29.3%) and 26.30% (24.0-28.8%), respectively.
Conclusions: Based on these results, strain ChDC B114^T (= KCOM 2030^T) should be classified as a novel species of genus Lachnoanaerobaculum, for which the name Lachnoanaerobaculum gingivalis sp. nov. is proposed.
(This research was supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Ministry of Science and ICT (2017M3A9B8065844) and in part by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2018R1A2B5002239).