Comamonas endophytica sp. nov., a novel indole acetic acid producing endophyte isolated from bamboo in China

Two novel indole acetic acid-producing strains, 5MLIR^T and D4N7, were isolated from Indosasa shibataeoides in Yongzhou, Hunan province, and Phyllostachys edulis in Hangzhou, Zhejiang province, respectively. Based on their 16S rRNA sequences, strains 5MLIR^T and D4N7 were closely related to Comamonas antarcticus 16-35-5^T (98.4 % sequence similarity), and the results of 92-core gene phylogenetic trees showed that strains 5MLIR^T and D4N7 formed a phylogenetic lineage within the clade comprising Comamonas species. The complete genome size of strain 5MLIR^T was 4.49 Mb including two plasmids, and the DNA G+C content was 66.5 mol%. The draft genome of strain D4N7 was 4.26 Mb with 66.7 mol% G+C content. The average nucleotide identity and digital DNA-DNA hybridization values among strain 5MLIR^T and species in the genus Comamonas were all below the species delineation threshold. The colonies of strain 5MLIR^T and D4N7 were circular with regular margins, convex, pale yellow and 1.0-2.0 mm in diameter when incubated at 30 °C for 3 days. Strains 5MLIR^T and D4N7 grew optimally at 30 °C, pH 7.0 and 1.0 % NaCl. The respiratory isoprenoid quinone was ubiquinone-8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Polyphasic analyses indicated that strains 5MLIR^T and D4N7 could be distinguished from related validly named Comamonas species and represent a novel species of the genus Comamonas, for which the name Comamonas endophytica sp. nov. is proposed. The type strain is 5MLIR^T (=ACCC 62069^T=GDMCC 1.2958^T=JCM 35331^T).