Mucilaginibacter gossypii sp. nov. and Mucilaginibacter gossypiicola sp. nov., plant-growth-promoting bacteria isolated from cotton rhizosphere soils

Abstract

Two isolates from rhizosphere soil of cotton, designated Gh-67T and Gh-48T, which produced large amounts of extracellular polysaccharide and possessed plant-growth-promoting traits, were characterized phenotypically and genotypically. The strains were Gram-negative and cells were non-motile rods that grew optimally at 28 °C and grew between pH 4 and 7. 16S rRNA gene sequence analysis of strains Gh-67T and Gh-48T placed them in the genus Mucilaginibacter, with pairwise sequence similarity between them and type strains from related genera ranging from 93.9 to 98.2 %. The major fatty acids were iso-C15 : 0, C16 : 0 and summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH). The strains contained MK-7 as the major isoprenoid quinone. The DNA G+C contents of strains Gh-67T and Gh-48T were 46.7 and 44.2 mol%, respectively. The low DNA–DNA hybridization value (18 %) and a number of phenotypic differences between strains Gh-48T and Gh-67T indicated that they represent two separate species. Results of phenotypic, phylogenetic and genotypic analysis revealed that the strains were separated from the species of Mucilaginibacter described to date. Therefore, strains Gh-67T and Gh-48T represent novel species of Mucilaginibacter, for which we propose the names Mucilaginibacter gossypii sp. nov. (type strain Gh-67T =NCIMB 14470T =KCTC 22380T) and Mucilaginibacter gossypiicola sp. nov. (type strain Gh-48T =NCIMB 14471T =KCTC 22379T).

Mucilaginibacter sabulilitoris sp. nov., isolated from marine sand in a firth

“…Both strains are negative for Gram-staining*; flagellar and gliding motilities*; anaerobic growth*; growth* with 2 % (w/v) NaCl; production of flexirubin-type pigments*; utilization of erythritol, D- chemotaxonomic properties from the other species of the genus Mucilaginibacter (Table 2; Fig. S1; Pankratov et al, 2007;Baik et al, 2010;Madhaiyan et al, 2010;Männistö et al, 2010;Kim et al, 2010Kim et al, , 2012a.…”

“…Hence, it is appropriate to classify strain SMS-12 T as a member of the genus Mucilaginibacter as shown by phylogenetic inference and the absence of differentiating chemotaxonomic properties from the other species of the genus Mucilaginibacter (Table 2; Fig. S1; Pankratov et al, 2007;Baik et al, 2010;Madhaiyan et al, 2010; Männistö et al, 2010;Kim et al, 2010Kim et al, , 2012a.DNA-DNA hybridization was performed fluorometrically by the method of Ezaki et al (1989) using photobiotinlabelled DNA probes and microdilution wells. Hybridization was performed at 45 u C with five replications for each sample.…”

“…At the time of writing, the genus Mucilaginibacter comprised 21 recognized species (Pankratov et al, 2007;Urai et al, 2008;An et al, 2009;Luo et al, 2009;Jeon et al, 2009;Baik et al, 2010;Madhaiyan et al, 2010; Männistö et al, 2010;Kim et al, 2010Kim et al, , 2011Kim et al, , 2012aJoung & Joh, 2011;Kang et al, 2011; Cui et al, 2011a, b;Han et al, 2012; Jiang et al, 2012;Yoon et al, 2012). Members of the genus Mucilaginibacter have been isolated from peat bog, soil, dried rice straw, wetland freshwater, tidal flats, marine sand, the rhizosphere of plants and compost (Pankratov et al, 2007;Urai et al, 2008;An et al, 2009;Baik et al, 2010;Madhaiyan et al, 2010;Kim et al, 2010Kim et al, , 2012a Cui et al, 2011a;Kang et al, 2011;Yoon et al, 2012). In this study, we describe a Mucilaginibacter-like bacterial strain, designated SMS-12 T , isolated from marine sand in a firth on the western coast of South Korea.…”

Mucilaginibacter yixingensis sp. nov., isolated from vegetable soil

“…Species of the genus Mucilaginibacter contain iso-C 15 : 0 and summed feature 3 (iso-C 15 : 0 2-OH and/or C 16 : 1 v7c) as major fatty acids and MK-7 as the major menaquinone. At the time of writing, the genus Mucilaginibacter comprises 34 recognized species, most of which have been isolated from a peat bog, soil, dried rice straw wetland, freshwater, the rhizosphere of various plants, tidal flat sediment and lichen (Pankratov et al, 2007;Urai et al, 2008;An et al, 2009;Baik et al, 2010;Madhaiyan et al, 2010). In this study, we report on the taxonomic characterization of a bacterial strain, YX-36 T , isolated from a vegetable soil, which is phylogenetically related to the genus Mucilaginibacter and represents a novel species.…”

Mucilaginibacter gynuensis sp. nov., isolated from rotten wood

“…The number of species in the genus has increased rapidly during last two years and at the time of writing the genus comprises 23 species with validly published names including the recently reported species Mucilaginibacter myungsuensis (Joung & Joh, 2011), Mucilaginibacter composti (Cui et al, 2011), Mucilaginibacter boryungensis (Kang et al, 2011), Mucilaginibacter soli (Jiang et al, 2012), Mucilaginibacter angelicae (Kim et al, 2012a), Mucilaginibacter polysacchareus (Han et al, 2012), Mucilaginibacter lutimaris (Kim et al, 2012b), Mucilaginibacter litoreus (Yoon et al, 2012) and Mucilaginibacter jinjuensis (Khan et al, 2013). Members of the genus Mucilaginibacter are commonly rod-shaped, nonmotile, non-spore-forming, Gram-negative and produce exopolysaccharide (Han et al, 2012, Madhaiyan et al, 2010.…”