Apilactobacillus zhangqiuensis sp. nov. and Apilactobacillus xinyiensis sp. nov., isolated from the gut of honeybee (Apis mellifera)

Three Gram--stain--positive bacterial strains (designated F502--1T, F575--4T and F582--1) were isolated from the gut of honeybee (Apis mellifera). These strains were characterized using a polyphasic taxonomic approach. Results of 16S rRNA gene sequence analysis indicated that strain F502--1T was phylogenetically related to the type strains of Apilactobacillus kunkeei, Apilactobacillus nanyangensis and Apilactobacillus apinorum, having 98.7-99.9% 16S rRNA gene sequence similarities, 84.6-92.5 % pheS sequence similarities and 95.2-99.0 % rpoA sequence similarities, and that strains F575--4T and F582--1 were closely related to the type strain of Apilactobacillus ozensis, having 99.7 and 99.4% 16S rRNA gene sequence similarities, respectively. Strains F575--4T and F582--1 had less than 88.7% pheS and 96.4 % rpoA sequence similarities to strain F502--1T and type strains of all Apilactobacillus species. The average nucleotide identity and digital DNA-DNA hybridization values between strains F502--1T, F575--4T, F582--1 and type strains of all Apilactobacillus species were less than 91.3 and 43.5 %, respectively, confirming that they represent two novel species within the genus Apilactobacillus. Based upon the data obtained in the present study, two novel species, Apilactobacillus zhangqiuensis sp. nov. and Apilactobacillus xinyiensis sp. nov., are proposed and the type strains are F502--1T (=JCM 34500T=CCTCC AB 2021026T) and F575--4T (=JCM 34501T=CCTCC AB 2021028T), respectively.

Automated summary

Three Gram-stain-positive bacterial strains were isolated from honeybee gut and characterized using a polyphasic taxonomic approach. Genetic analysis revealed that two of the strains were closely related to known Apilactobacillus species but had lower sequence similarities, leading to the proposal of two new species within the genus. The findings highlight the diversity of bacterial strains in the honeybee gut.