Description of Erythrobacter mangrovi sp. nov., an aerobic bacterium from rhizosphere soil of mangrove plant (Kandelia candel).

A novel Gram-stain negative, aerobic, non-motile, rod-shaped bacterium, designated as strain EB310T, was isolated from rhizosphere soil of mangrove plant Kandelia candel in Fugong village, Zhangzhou, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain EB310T belonged to the genus Erythrobacter, clustering with Erythrobacter pelagi JCM 17468T, Erythrobacter lutimaris KCTC 42109T and Erythrobacter marisflavi KCTC 62896T, and showed the highest 16S rRNA gene sequence similarity of 97.5% to Erythrobacter pelagi JCM 17468T. The genomic average nucleotide identity and in silico DNA-DNA hybridization values between strain EB310T and the reference strains were 71.0-75.5% and 19.8-20.0%, respectively. Growth ranges of the isolate occurred at 10-45 °C (optimum 28-30 °C), pH 5.5-9.5 (optimum pH 7.5) and 0-9.0% NaCl concentrations (optimum 2.0%, w/v). The strain did not produce bacteriochlorophyll a and flexirubin, but produced carotenoids. The strain contained Q-10 as the predominant ubiquinone and summed feature 3 (C16:1 ω7c/C16:1 ω6c) and summed feature 8 (C18:1 ω6c/C18:1 ω7c) as the major fatty acids. The major polar lipids were sphingoglycolipid, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylcholine. Differential phenotypic characteristics, together with chemotaxonomic, phylogenetic and genomic distinctiveness, indicated that strain EB310T is distinguishable from other members of the genus Erythrobacter. On the basis of the data exhibited, strain EB310T is considered to represent a novel species of the genus Erythrobacter, for which the name Erythrobacter mangrovi sp. nov., is proposed. The type strain is EB310T (= KCTC 72109T = MCCC 1K03690T). The genomic DNA G + C content is 62.9 mol%.

Correction to: Description of Wenzhouxiangella salilacus sp. nov., a moderate halophilic bacterium isolated from a salt lake in Xinjiang Province, China.

In the original publication of the article, the deposit accession numbers of strain 15181T in the acknowledgment section were incorrectly provided as "KCTC 62172T and MCCC 1K03442T".

Description of Wenzhouxiangella salilacus sp. nov., a moderate halophilic bacterium isolated from a salt lake in Xinjiang Province, China.

A Gram-stain negative, non-motile, strictly aerobic and rod-shaped bacterium, designated as 15181T, was isolated from a salt lake in Xinjiang Province, China. Strain 15181T was able to grow at 10-40 °C (optimum 37 °C), pH 6.0-8.5 (optimum 7.0) and with 1-14% NaCl (optimum 4%, w/v). According to phylogenetic analysis based on 16S rRNA gene sequences, strain 15181T was assigned to the genus Wenzhouxiangella with high 16S rRNA gene sequence similarity of 97.4% to Wenzhouxiangella sediminis XDB06T, followed by Wenzhouxiangella marina KCTC 42284T (95.9%). Strain 15181T exhibited ANI values of 80.0% and 72.0% to W. sediminis XDB06T and W. marina KCTC 42284T, respectively. The in silico DDH analysis revealed that strain 15181T shared 19.1% and 18.7% DNA relatedness with W. sediminis XDB06T and W. marina KCTC 42284T, respectively. Chemotaxonomic analysis showed that the sole respiratory quinone was ubiquinone-8, the major fatty acids included iso-C15:0, iso-C16:0 and summed feature 9 (C16:0 10-methyl and/or iso-C17:1ω9c). The major polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified glycolipids, two unidentified phospholipids, two unidentified aminophospholipids and an unidentified lipid. On the basis of phenotypic, genotypic and chemotaxonomic characteristics presented in this study, strain 15181T is concluded to represent a novel species in the genus Wenzhouxiangella, for which the name Wenzhouxiangella salilacus sp. nov. is proposed. The type strain is 15181T (=KCTC 62172T=MCCC 1K03442T).

Three New Isoflavonoid Glycosides from the Mangrove-Derived Actinomycete Micromonospora aurantiaca 110B.

The mangrove ecosystem is a rich resource for the discovery of actinomycetes with potential applications in pharmaceutical science. Besides the genus Streptomyces, Micromonospora is also a source of new bioactive agents. We screened Micromonospora from the rhizosphere soil of mangrove plants in Fujian province, China, and 51 strains were obtained. Among them, the extracts of 12 isolates inhibited the growth of human lung carcinoma A549 cells. Strain 110B exhibited better cytotoxic activity, and its bioactive constituents were investigated. Consequently, three new isoflavonoid glycosides, daidzein-4'-(2-deoxy-α-l-fucopyranoside) (1), daidzein-7-(2-deoxy-α-l-fucopyranoside) (2), and daidzein-4',7-di-(2-deoxy-α-l-fucopyranoside) (3) were isolated from the fermentation broth of strain 110B. The structures of the new compounds were determined by spectroscopic methods, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESIMS). The result of medium-changing experiments implicated that these new compounds were microbial biotransformation products of strain M. aurantiaca 110B. The three compounds displayed moderate cytotoxic activity to the human lung carcinoma cell line A549, hepatocellular liver carcinoma cell line HepG2, and the human colon tumor cell line HCT116, whereas none of them showed antifungal or antibacterial activities.