Altererythrobacter halimionae sp. nov. and Altererythrobacter endophyticus sp. nov., two endophytes from the salt marsh plant Halimione portulacoides

Two Gram-negative, rod-shaped, motile bacterial strains, named CPA5Tand BR75T, were isolated from the halophyte Halimione portulacoides. Both presented optimum growth at 30°C, pH 7.0-7.5 and 1-25NaCl (w/v) for strain CPA5T, and pH 7.5-8.0 and 2%NaCl (w/v) for strain BR75T. Phylogenetic analyses based on 16S rRNA gene sequences affiliated both strains to the genus Altererythrobacter. CPA5Tpresented highest 16S rRNA gene sequence similarity with Altererythrobacter aestuarii KYW147T(96.5%), followed by Altererythrobacter namhicola KYW48T(95.9%), Novosphingobium indicum H25T (95.6%) and Altererythrobacter oceanensis Y2T(95.5%). BR75T displayed highest similarity with Altererythrobacter marensis MSW-14T(96.5%), followed by Altererythrobacter xinjiangensis S3-63T, Altererythrobacter luteolus SW-109Tand Altererythrobacter indicus MSSRF26T(96.1%). Neither strain contained Bacteriochlorophyll a. The main fatty acids observed for CPA5Twere C17:1ω6c and summed features 3 (C16:1ω7c and/or iso-C15:02-OH) and 8 (C18:1ω7c and/or C18:1ω6c). The latter summed feature was the dominant fatty acid observed for strain BR75Tas well. The major polar lipids were phosphatidylethanolamine, unidentified phospholipids and unidentified glycolipids for both strains. The predominant ubiquinone was Q-10 for both strains, and the DNA G+C contents were 63.4mol% and 58.3mol% for CPA5Tand BR75T, respectively. Based on phenotypic and genotypic results, both strains represent novel species belonging to the genus Altererythrobacter for which the names Altererythrobacter halimionae sp. nov. (type strain CPA5T=CECT9130T=LMG 29519T) and Altererythrobacter endophyticus sp. nov (type strain BR75T=CECT 9129T=LMG 29518T) are proposed.