Gracilibacillus thailandensis sp. nov., from fermented fish (pla-ra)

Abstract

A novel strain, designated TP2-8 T , was isolated from fermented fish (pla-ra) in Thailand. It stained Gram-positive and the cells were aerobic, endospore-forming rods. The strain grew at pH 6-8 (optimum pH 7), 15-55 6C (optimum 37 6C) and 1-22 % (w/v) NaCl (optimum 5-10 %). It contained meso-diaminopimelic in the cell-wall peptidoglycan. MK-7 and cellular fatty acids anteiso-C 15 : 0 , iso-C 15 : 0 and anteiso-C 17 : 0 were major components. Polar lipids diphosphatidylglycerol and phosphatidylglycerol and unidentified lipids were detected. The DNA G+C content was 37.6 mol%. Comparison of the 16S rRNA gene sequence of strain TP2-8 T with those of other members of the family Bacillaceae indicated that it was a member of the genus Gracilibacillus (94.9-99.2 % sequence similarity) and was closely related to Gracilibacillus saliphilus YIM 91119 T (99.2 % similarity), G. lacisalsi BH312 T (98.6 %), G. orientalis XH-63 T (97.7 %), 'G. quinghaiensis' YIM C229 (97.7 %) and G. boraciitolerans T-16X T (97.2 %). Strain TP2-8 T showed low DNA-DNA relatedness (¡49 %) to G. saliphilus YIM 91119 T , G. lacisalsi DSM 19029 T , G. orientalis CCM 7326 T , 'G. quinghaiensis' DSM 17858 and G. boraciitolerans JCM 21714 T . On the basis of the physiological and biochemical characteristics and molecular data presented, strain TP2-8 T is proposed to represent a novel species, Gracilibacillus thailandensis sp. nov. (type strain TP2-8 T 5JCM 15569 T 5PCU 304 T 5TISTR 1881 T ).The genus Gracilibacillus was described by Wainø et al. (1999) to accommodate moderately halophilic, endospore-forming bacteria. At the time of writing, the genus comprises seven species with validly published names: Gracilibacillus halotolerans, the type species, from surface mud of the Great Salt Lake (Wainø et al., 1999), G. dipsosauri, from a desert iguana (Lawson et al., 1996), G. orientalis (Carrasco et al., 2006), G. lacisalsi (Jeon et al., 2008) and G. saliphilus (Tang et al., 2009), from saline lakes, G. boraciitolerans, from soil (Ahmed et al., 2007) and G. halophilus, from a saline soil (Chen et al., 2008b). 'Gracilibacillus quinghaiensis' has been described from a salt-lake sediment (Chen et al., 2008a), but this name has not yet been validly published. These bacteria thrive in a maximum of 11-30 % NaCl and at 50 u C. Moderately halophilic bacteria are also found in many kinds of fermented food, including Jeotgalibacillus alimentarius, from jeotgal (Yoon et al., 2001), Lentibacillus juripiscarius and Lentibacillus halophilus, from fish sauce (Namwong et al., 2005; Tanasupawat et al., 2006), Lentibacillus kapialis, from fermented shrimp paste (Pakdeeto et al., 2007), and Piscibacillus salipiscarius, from fermented fish (pla-ra) (Tanasupawat et al., 2007). In the course of a study on bacterial diversity in fermented foods in Thailand, we isolated a novel Gracilibacillus-like strain, designated TP2-8 T , from plara, a traditional fermented fish, containing 7.8-17.9 % NaCl (w/v) (Phithakpol et al., 1995). In this paper, we describe its phenotypic and che...

Selection of Autochthonous Strains as Starter Cultures for Fermented Fish Products

“…Other researchers isolated moderately halophilic microrganisms with an optimal growth at 3% to 15% NaCl, that is, Tetragenococcus halophilus, Tetragenococcus muriaticus, Halobacillus thailandensis , and Lentibacillus juripiscarius (Thongsanit and others ; Namwong and others ). Moderately halophilic microorganisms are widely distributed in many kinds of fermented foods: for example, strains of Jeotgalibacillus alimentarius were found in jeotgal in Korea (Yoon and others ), L. juripiscarius and Lentibacillus halophilus , T. halophilus , and T. muriaticus in Thai fish sauce (Thongsanit and others ; Namwong and others ; Tanasupawat and others ), Bacillus vietnamensis in Vietnamese fishsauce (Noguchi and others ), Salinicoccus siamensis , Lentibacillus kapialis , and Oceanobacillus kapialis in Thai fermented shrimp paste (Pakdeeto and others ; Namwong and others ), and Piscibacillus salipiscarius , Salinivibrio siamensis , and Gracilibacillus thailandensis in salt‐fermented fish ( pla‐ra ) in Thailand (Tanasupawat and others ; Chamroensaksri and others , ).…”

Gracilibacillus salitolerans sp. nov., a moderate halophile isolated from saline soil in Northwest China

“…To date, according to the List of Prokaryotic Names with Standing in Nomenclature [2], there are at least 13 valid species in the genus Gracilibacillus, with the exception of several species that are not validly published yet. Most members of this genus were isolated from diverse salty environmental samples, such as salt lake [3], solar saltern soil [4], fermented fish [5], saline-alkaline soil [6] and salt glands of a desert iguana [7]. Taxonomically, Gracilibacillus species are shown to possess similar phenotypic and chemotaxonomic features and close phylogenetic relationship, for which they are commonly characterized as Gram-stain-positive, rod-shaped, endospore-forming, motile, halophilic or halotolerant bacteria containing menaquinone-7 (MK-7) as the major respiratory quinone and meso-diaminopimelic acid (meso-DAP) as the cell-wall diamino acid.…”

Genome sequence and description of Gracilibacillus timonensis sp. nov. strain Marseille‐P2481T, a moderate halophilic bacterium isolated from the human gut microflora

“…In most species, cells are motile due to peritrichous flagella and form endospores and white colonies (Wainø et al., ). Gracilibacillus species were isolated from diverse salty environmental samples, including sea water, salty lakes (Gao et al., ; Jeon et al., ), soil (Chen et al., ; Huo, Xu, Cui, & Wu, ), and/or food (Chamroensaksri et al., ; Diop et al., ).…”