Cognatishimia coralii sp. nov., a marine bacterium isolated from seawater surrounding corals

Coral reefs are declining due to the rising seawater temperature. Bacteria within and surrounding corals play key roles in maintaining the homeostasis of the coral holobiont. Research on coral-related bacteria could provide benefits for coral reef restoration. During the isolation of coral-associated bacteria, a Gram-stain-negative, motile bacterium (D5M38 T ) was isolated from seawater surrounding corals in Daya Bay, Shenzhen, PR China. Phylogenetic analysis revealed that strain D5M38 T represents a novel species in the genus Cognatishimia . The temperature range for strain D5M38 T growth was 10–40 °C, and the optimum temperature was 37 °C. The salinity range for the growth of this isolate was from 0 to 4.0 %, with an optimal salinity level of 0.5 %. The pH range necessary for strain D5M38 T growth was between pH 5.0 and 9.0, with an optimal pH being 7.5. The predominant fatty acid was summed feature 8 (65.0 %). The major respiratory quinone was Q-10. The DNA G+C content was 56.8 %. The genome size was 3.88 Mb. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA–DNA hybridization (dDDH) values between strain D5M38 T and its two closest neighbours, Cognatishimia activa LMG 29900 T and Cognatishimia maritima KCTC 23347 T , were 73.2/73.6%, 73.2/73.6% and 19.7/19.5%, respectively. Strain D5M38 T was clearly distinct from its closest neighbours C. activa LMG 29900 T and C. maritima KCTC 23347 T , with 16S rRNA gene sequence similarity values of 97.5 and 97.3 %, respectively. The phylogenetic analysis, along with the ANI, AAI, and dDDH values, demonstrated that strain D5M38 T is a member of the genus Cognatishimia , and is distinct from the other two recognized species within this genus. The physiological, biochemical and chemotaxonomic characteristics also supported the species novelty of strain D5M38 T . Thus, strain D5M38 T is considered to be classified as representing a novel species in the genus Cognatishimia , for which the name Cognatishimia coralii sp. nov. is proposed. The type strain is D5M38 T (=MCCC 1K08692 T =KCTC 8160 T ).