Ancylobacter mangrovi sp. nov., a novel endophytic bacterium isolated from mangrove plant

Two novel strains GSK1Z-4-2T and MQZ15Z-1 were isolated from branches of mangrove plants collected from Guangxi Zhuang Autonomous Region, China. Both strains were Gram-negative, aerobic, non-flagellated and non-spore-forming bacteria. The comparison of 16S rRNA gene sequences initially indicated that the two strains were assigned to the genus Ancylobacter with sharing the highest similarity to Ancylobacter pratisalsi DSM 102029T (97.3%). The 16S rRNA gene sequence similarity, average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) values between strains GSK1Z-4-2T and MQZ15Z-1 were 99.9%, 97.4% and 77.4%, respectively, which revealed that the two strains belonged to the same species. Phylogenetic analyses based on 16S rRNA gene sequences and the core proteome showed that the two strains formed a well-supported cluster with A. pratisalsi DSM 102029T. Moreover, the ANI and isDDH values between strain GSK1Z-4-2T and A. pratisalsi DSM 102029T were 83.0% and 25.8%, respectively, demonstrating that strain GSK1Z-4-2T was a previously undescribed species. Meanwhile, strains GSK1Z-4-2T and MQZ15Z-1 exhibited most of chemotaxonomic and phenotypic features consistent with the description of the genus Ancylobacter. Based on the polyphasic data, strains GSK1Z-4-2T and MQZ15Z-1 should represent a novel species of the genus Ancylobacter, for which the name Ancylobacter mangrovi sp. nov. is proposed. The type strain is GSK1Z-4-2T (=MCCC 1K07181T = JCM 34924T).