Description and genomic characterization of Jiella flava sp. nov., isolated from Acrostichum aureum

Abstract

Two endophytic bacteria, designated strains CQZ9-1^T and MQZ9-1, were isolated from semi-mangrove plant Acrostichum aureum collected from Maowei Sea Mangrove Nature Reserve in Guangxi Zhuang Autonomous Region, PR China. The two strains possessed almost identical 16S rRNA gene sequences (99.7 %). The average nucleotide identity (ANI), average amino acid identity (AAI) and the digital DNA-DNA hybridization (dDDH) values between the two strains were 100 %, indicating that they represented the same species. The 16S rRNA gene sequence similarities between strains CQZ9-1^T, MQZ9-1 and the most closely related type strains, Jiella mangrovi KSK16Y-1^T, Jiella sonneratiae MQZ13P-4^T and Jiella endophytica CBS 5Q-3^T were 98.0-98.1, 97.3-97.4 and 97.3-97.4 %, respectively. The results of phylogenetic analyses based on 16S rRNA gene sequences and genome sequences indicated that CQZ9-1^T and MQZ9-1 formed a distinct lineage with J. endophytica CBS5Q-3^T, Jiella pacifica 40Bstr34^T, J. mangrovi KSK16Y-1^T, J. sonneratiae MQZ13P-4^T, Jiella aquimaris JCM 30119^T and J. aquimaris 22II-16-19i. The draft genomes of strains CQZ9-1^T and MQZ9-1 were 4 162 933 bp and 4 164 266 bp in size, respectively, and their DNA G+C contents were both 63.8 %. Comparative genome analysis of the two strains and the type strains of related species revealed ANI, AAI and dDDH values below the cut-off levels of 95-96, 95.5 and 70 %, respectively. The ubiquinone detected in CQZ9-1^T was Q-10. The major cellular fatty acid of strains CQZ9-1^T and MQZ9-1 was found to be C_18:1ω7c. Combined data from phenotypic, phylogenetic and chemotaxonomic studies indicated that CQZ9-1^T and MQZ9-1 represent a novel species of the genus Jiella, for which the name Jiella flava sp. nov. is proposed. The type strain is CQZ9-1^T (= CGMCC 1.18725^T = JCM 34331^T).

Keywords: Acrostichum aureum; Jiella flava; novel species.