Sphingobacterium detergens sp. nov., a surfactant-producing bacterium isolated from soil

Abstract

A novel Gram-negative-staining strain, designated 6.2S T , was isolated from a soil sample and identified as a biosurfactant producer. Its taxonomic position was investigated using a polyphasic approach. The cells were non-motile, non-spore-forming rods. The organism grew optimally at 30-37 6C, with 0-3 % (w/v) NaCl, and at pH 7.0. Based on 16S rRNA gene sequence analysis, strain 6.2ST was found to be a member of the genus hybridization experiments between the novel strain and its closest relatives gave a DNA-DNA relatedness value of less than 70 %, and consequently confirmed that this new strain did not belong to a previously described species of the genus Sphingobacterium. The major fatty acids were summed feature 3 (iso-C 15 : 0 2 OH and/or C 16 : 1 v7c); iso-C 15 : 0 ; iso-C 17 : 0 3-OH and C 16 : 0 . The G+C content of the genomic DNA was 40.0 mol%. According to its phenotypic and genotypic characteristics and the phylogenetic data, strain 6.2S T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium detergens sp. nov. is proposed. The type strain is 6.2S T (5CECT 7938 T 5LMG 26465 T ).During screening experiments for new biosurfactants, several soil samples from the Azores Islands were analysed. Strain 6.2S T was selected for its ability to reduce the surface tension of the medium to 32 mN m 21 due to the production of a mixture of compounds with surface activity (Burgos-Díaz et al., 2011). This strain was initially identified as Sphingobacterium multivorum, based on cell and colony morphology, as well as the results of the API 20 NE bacterial identification kit. The results of 16S rRNA gene sequence analysis showed that strain 6.2ST belonged to the genus Sphingobacterium, and that its nearest relative was Sphingobacterium siyangense. The aim of the present study was to clarify the taxonomic position of this new strain by using a polyphasic approach, including phenotypic, chemotaxonomic, genotypic and phylogenetic analyses.The family Sphingobacteriaceae belongs to the phylum Bacteroidetes and is composed of eight genera (Sphingobacterium, Pedobacter, Mucilaginibacter, Nubsella, Olivibacter, Parapedobacter, Pseudosphingobacterium and Solitalea) of bacteria commonly isolated from the environment (http:// www.bacterio.cict.fr). The genus Sphingobacterium was established by Yabuuchi et al. (1983), based on the presence of high concentrations of sphingophospholipids in cellular lipid components. Two species of the genus Flavobacterium were reclassified as members of this new genus (Sphingobacterium multivorum and Sphingobacterium spiritivorum) and an additional species (Sphingobacterium mizutae) was recognized. Members of the genus Sphingobacterium are Gram-negative-staining rods, that give a positive reaction for catalase and oxidase, a negative reaction for heparinase, gelatinase and indole production and have iso-C 15 : 0 , iso-C 15 : 0 2-OH, C 16 : 1 v7c and C 17 : 0 3-OH as the main fatty acids (Kim et al., 2006;Liu et al., 2008). These organisms are frequently isolat...

Sphingobacterium paludis sp. nov., isolated from wetland soil

“…The genus Sphingobacterium was first proposed by Yabuuchi et al (1983) and initially included three species, Sphingobacterium spiritivorum (type species), Sphingobacterium mizutaii and Sphingobacterium multivorum . At the time of writing, the genus comprises 28 species with validly published names: Sphingobacterium spiritivorum (Yabuuchi et al , 1983), Sphingobacterium mizutaii (Yabuuchi et al , 1983), Sphingobacterium multivorum (Yabuuchi et al , 1983), Sphingobacterium antarcticus (Shivaji et al , 1992), Sphingobacterium faecium (Takeuchi & Yokota, 1992), Sphingobacterium thalpophilum (Takeuchi & Yokota, 1992), Sphingobacterium daejeonense (Kim et al , 2006), Sphingobacterium composti (represented by T5-12 T ; Ten et al , 2006), Sphingobacterium canadense (Mehnaz et al , 2007), Sphingobacterium composti (represented by 4M24 T ; Yoo et al , 2007), Sphingobacterium anhuiense (Wei et al , 2008), Sphingobacterium kitahiroshimense (Matsuyama et al , 2008), Sphingobacterium siyangense (Liu et al , 2008), Sphingobacterium bambusae (Duan et al , 2009), Sphingobacterium shayense (He et al , 2010), Sphingobacterium alimentarium (Schmidt et al , 2012), Sphingobacterium detergens (Marqués et al , 2012), Sphingobacterium kyonggiense …”

Sphingobacterium caeni sp. nov., isolated from activated sludge

“…The genus Sphingobacterium was proposed by Yabuuchi et al (1983) to include Gram-negative rods that are positive for catalase and oxidase, negative for heparinase, gelatinase and indole production and contain iso-C 15 : 0 , iso-C 15 : 0 2-OH, C 16 : 1 ω7 c and C 17 : 0 3-OH as the main fatty acids (Takeuchi & Yokota, 1992; Steyn et al , 1998). Members of the genus Sphingobacterium are metabolically versatile and are widely distributed in soil (Shivaji et al , 1992; Mehnaz et al , 2007; Liu et al , 2008; Wei et al , 2008; Matsuyama et al , 2008; Duan et al , 2009; He et al , 2010; Choi & Lee, 2012; Marqués et al , 2012), raw milk (Schmidt et al , 2012), fresh leaves (Liu et al , 2012), clinical specimens (Yabuuchi et al , 1983), activated sludge (Zhang et al , 2012) and compost (Ten et al , 2006; Kim et al , 2006; Yoo et al , 2007). During an investigation of the microbial diversity of wastewater from the wastewater treatment facility for butachlor ( N -butoxymethl-chloro-2,6-diethylacetnilide) manufacture (Kunshan, Jiangsu province, China, 31° 22′ N 120° 56′ E), a bacterium, designated strain DC-8 T , was isolated from the activated sludge.…”

In vitro study of the cytotoxicity and antiproliferative effects of surfactants produced by Sphingobacterium detergens

“…For BS production, S. detergens (strain 6.2S) (Marqués et al, 2012) was grown aerobically in 200 mL of mineral salt medium (MCA) with the following composition (g/L): KH 2 PO 4 , 1.0; K 2 HPO 4 , 2.0; CO(NH 2 ) 2 , 0,88; CaCl 2 , 0.01; FeSO 4 ·7H 2 O, 0.01; MgSO 4 ·7H 2 O, 0.5; KCl, 1.0; d-glucose, 20; trace elements solution 0.05 mL ), 1.5% C 11-13 (C 10 9.3%, C 11 32.4%, C 12 31.3%, C 13 26.7%) plus 2% (v/v) of inoculum suspension in Ringer's solution. The inoculum consisted of a strain 6.2S suspension precultured in TSA, with turbidity equal to MacFarland scale no.…”