Mucilaginibacter kameinonensis sp., nov., isolated from garden soil

Abstract

An extracellular polysaccharide-producing bacterium, strain SCK T , was isolated from a soil sample taken from Kameino, Fujisawa, Japan. The isolate was Gram-negative and cells were nonmotile, irregular-shaped rods that grew optimally at 25 6C and grew between pH 5 and 8. Strain SCK T contained MK-7 as the major isoprenoid quinone, iso-C 15 : 0 and C 16 : 1 v7c and/or iso-C 15 : 0 2-OH as the major fatty acids and sphingolipids, with d-17 : 0 as the main dihydrosphingosine. Flexirubin-type pigments were also present. The DNA G+C content was 43.7 mol%. On the basis of 16S rRNA gene sequence analysis, strain SCK T was shown to belong to the genus Mucilaginibacter. The 16S rRNA gene sequence similarity between strain SCK T and the two type strains of Mucilaginibacter was 93 %. The results of physiological and biochemical tests allowed phenotypic differentiation of the strain from published Mucilaginibacter species. Therefore, strain SCK T represents a novel species, for which the name Mucilaginibacter kameinonensis sp. nov. is proposed. The type strain is SCK T (5NBRC 102645 T 5KCTC T ).It has been reported that some bacterial strains belonging to the genus Rhodococcus produce extracellular polysaccharides (EPS), including fatty acids containing EPS, and that these EPS have a variety of functions, including protection of bacterial cells from the toxicity of hydrocarbons (Aizawa et al., 2005;Iwabuchi et al., 2000), emulsification, moisture absorption (Urai et al., 2002(Urai et al., , 2004 and stimulation of degradation of polyaromatic hydrocarbons (PAH) spilled in marine environments, the latter probably occurring via stimulation of marine PAHassimilating bacteria (Iwabuchi et al., 2002). These EPS are acidic, high-molecular-mass polysaccharides containing uronic acids (Urai et al., 2006a(Urai et al., , b, 2007a. During the screening for micro-organisms that were able to assimilate the EPS produced by Rhodococcus rhodochrous S-2 (S-2 EPS), strain SCK T was isolated from a soil sample taken from a garden on our campus at Kameino, Fujisawa, Japan. The strain formed mucoid colonies and produced a large amount of EPS. On the basis of phenotypic, genotypic, chemotaxonomic and phylogenetic analyses, it was concluded that strain SCK T was affiliated with the genus Mucilaginibacter and represents a novel species of this genus.The genus Mucilaginibacter was established recently and belongs to the family Sphingobacteriaceae; it currently includes two species, Mucilaginibacter gracilis and Mucilaginibacter paludis, which were isolated from an acidic Sphagnum peat bog as pectin-, xylan-and laminarindegrading bacteria (Pankratov et al., 2007). 21 . This EPS contained D-galactose, D-glucose, D-mannose and L-rhamnose in equimolar amounts. The chemical structure and functional aspects of the EPS produced by strain SCK T will be described elsewhere. The strain showed good growth on TSA at 5-30 u C, with an optimum at 25 u C, but did not grow at 45 u C. Strain SCK T showed good growth in tryptic soy broth (TSB) over the pH range 4-9...

Mucilaginibacter frigoritolerans sp. nov., Mucilaginibacter lappiensis sp. nov. and Mucilaginibacter mallensis sp. nov., isolated from soil and lichen samples

“…However, the degree of 16S rRNA gene (Urai et al, 2008). All strains are positive for acid production from cellobiose, galactose and maltose and catalase and oxidase activities.…”

“…The genus Mucilaginibacter of the family Sphingobacteriaceae was described by Pankratov et al (2007) and at present comprises seven species: Mucilaginibacter paludis and Mucilaginibacter gracilis (Pankratov et al, 2007), Mucilaginibacter kameinonensis (Urai et al, 2008), Mucilaginibacter daejeonensis , Mucilaginibacter ximonensis (Luo et al, 2009), Mucilaginibacter oryzae (Jeon et al, 2009) and Mucilaginibacter rigui (Baik et al, 2010). Members of the family Sphingobacteriaceae are commonly isolated from cold environments such as alpine (Margesin et al, 2003;Shivaji et al, 2005) and tundra soil (Männistö & Häggblom, 2006).…”

Mucilaginibacter koreensis sp. nov., isolated from leaf mould

“…The description of the genus was emended by Urai et al (2008) and Baik et al (2010). The genus groups oxidase-positive, strictly aerobic or facultatively anaerobic bacteria that contain MK-7 as the major respiratory quinone and straight and branchedsaturated fatty acids, and have a DNA G+C content in the range 42.4-49.8 mol%.…”

“…Members of the genus Mucilaginibacter have been isolated from various sources including peat bog, rice straw, wetland freshwater, marine sand, soil and tidal flat sediment (Pankratov et al, 2007;Urai et al, 2008;An et al, 2009;Baik et al, 2010;Yoon et al, 2012; Jiang et al, 2012;Kim et al, 2012b;Han et al, 2012;Khan et al, 2013). Strain TF8 T was isolated from leaf mould, collected at the campus of Dankook University, Cheonan, Republic of Korea (36 u 839 85.720 N 127 u 169 87.580 E).…”

Mucilaginibacter roseus sp. nov., isolated from a freshwater river

“…The genus Mucilaginibacter, first proposed by Pankratov et al (2007) and subsequently emended by Urai et al (2008), Baik et al (2010) and Chen et al (2014), belongs to the family Sphingobacteriaceae, order Sphingobacteriales, class Sphingobacteria, phylum Bacteroidetes (Ludwig et al, 2011). At the time of writing, this genus comprises 33 species with validly published names (http://www.…”