Octadecabacter algicola sp. nov. and Octadecabacter dasysiphoniae sp. nov., isolated from a marine red alga and emended description of the genus Octadecabacter

Abstract

Two Gram-stain-negative, strictly aerobic, catalase- and oxidase-positive and non-motile rod-shaped bacteria, strains D2-3T and G9-8T, were isolated from a marine red alga. Both strains contained ubiquinone-10 as the sole isoprenoid quinone. As the major cellular fatty acids (>5.0 %), D2-3T contained C16 : 0, 11-methyl-C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), whereas G9-8T contained C16 : 0, 11-methyl-C18 : 1ω7c, C12 : 1 3-OH, and summed feature 8. The DNA G+C contents of D2-3T and G9-8T were 54.4 % and 56.0 %, respectively. As the major polar lipids, phosphatidylglycerol, diphosphatidylglycerol and unidentified phospholipid, aminolipid and lipid were identified from both strains, and phosphatidylcholine was additionally detected from G9-8T only. The 16S rRNA gene sequence similarity of D2-3T and G9-8T was 98.5 % and their digital DNA–DNA hybridization (DDH) value was 19.1 %. Phylogenetic analyses based on 16S rRNA gene and genome sequences revealed that D2-3T and G9-8T formed respectively distinct phylogenetic lineages within the genus Octadecabacter . D2-3T and G9-8T were most closely related to Octadecabacter ascidiaceicola RA1-3T and Octadecabacter antarcticus 307T, with 98.9 % and 98.5 % 16S rRNA gene sequence similarities, respectively, and digital DDH values between D2-3T and O. ascidiaceicola and between G9-8T and O. antarcticus were 18.3 % and 19.5 %, respectively. Phenotypic, chemotaxonomic and molecular features support the hypothesis that D2-3T and G9-8T represent two novel species of the genus Octadecabacter , for which the names Octadecabacter algicola sp. nov. and Octadecabacter dasysiphoniae sp. nov. are proposed. The type strains of O. algicola and O. dasysiphoniae are D2-3T (=KACC 22493T =JCM 34969T) and G9-8T (=KACC 22488T =JCM 34973T), respectively.

Devosia rhodophyticola sp. nov. and Devosia algicola sp. nov., isolated from a marine red alga

“…Aliquots of 100 µl from each serial dilution were plated on marine agar 2216 (MA; BD) and incubated aerobically at 25 °C for 7 days. Colonies grown on MA were subjected to PCR amplification of the 16S rRNA gene using the universal primers F1 (5′-AGAGTTTGATCMTGGCTCAG-3′) and R13 (5′-TACG GYTA CCTT GTTA CGACTT-3′) [15]. The resulting PCR amplicons were double-digested with restriction enzymes HaeIII and HhaI, and their restriction fragment patterns were analysed on 2 % agarose gel.…”

“…Colonies exhibiting identical restriction fragment patterns of the 16S rRNA genes were excluded from further analysis. Sequencing of representative PCR amplicons with unique fragment patterns was performed using the universal primer 340F (5′-CCTACGGGAGGCAGCAG-3′) [15] at Macrogen (Seoul, Republic of Korea). The obtained 16S rRNA gene sequences were compared with sequences of all validly published type species available in the EzBioCloud server (www.ezbiocloud.net/identify) [17].…”

“…Strains G2-5 T and G20-9 T were isolated from the phycosphere of a Chondrus species, a marine red alga, collected from the Gonghyeonjin, Gangwon-do, Republic of Korea (38° 21′ 21″ N, 128° 30′ 45″ E), as described previously [15]. In brief, the collected red alga underwent a thorough wash using artificial seawater (ASW; 20.0 g NaCl, 2.9 g MgSO 4 , 4.5 g MgCl 2 •6H 2 O, 0.6 g KCl, 1.8 g CaCl 2 •2H 2 O per litre) through mechanical vortexing.…”

“…In addition, summed feature 8 (C 18 : 1 ω 7 c and/or C 18 : 1 ω 6 c ), C 18 : 0 and 11-methyl-C 18 : 1 ω 7 c and diphosphatidylglycerol (DPG) and phosphatidylglycerol (PG) have been reported as major fatty acids and polar lipids of the genus Devosia , respectively. In the course of our research on interactions between marine red algae and bacteria, numerous novel bacteria have been isolated from marine red algae [14–16]. In this study, we have isolated two putatively novel species within the genus Devosia from a marine red alga and their taxonomic properties were characterized using a polyphasic approach.…”

Hoeflea algicola sp. nov. and Hoeflea ulvae sp. nov., isolated from phycosphere of marine algae

“… Hoeflea species also have been reported as isolated from marine photosynthetic organisms, including dinoflagellates and cyanobacteria [4, 6], and are thought to be related to the growth of marine algae. We previously isolated bacterial strains that play an important role in contributing to the growth of algae to study algae–bacteria interactions [8, 9]. During the isolation process, two bacterial strains belonging to the genus Hoeflea , G2-23 T and J2-29 T , were isolated from the phycosphere of species of the genera Chondrus and Ulva of marine algae, respectively, and we analysed their taxonomic characteristics using a polyphasic approach.…”