Haloterrigena jeotgali sp. nov., an extremely halophilic archaeon from salt-fermented food

Abstract

A novel red-pigmented halophilic archaeon, strain A29T , was isolated from shrimp jeotgal, a traditional salt-fermented food from Korea. This strain grows in the ranges 10-30 % (w/v) NaCl, 17-50 6C and pH 6.5-8.5, with optimal growth occurring at 15-20 % NaCl, 37-45 6C and pH 7.0-7.5. The isolate is Gram-negative and non-motile. Phylogenetic analysis, based on 16S rRNA gene sequences, showed that strain A29 T is associated with the genus Haloterrigena and closely related to the species Haloterrigena thermotolerans (99.0 % similarity). However, DNA-DNA hybridization experiments revealed that the level of hybridization between strain A29 T and related strains of Haloterrigena is less than 70 %. The polar lipid fraction consists of phosphatidylglyerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me) and mannose-2,6-disulfate(1-2)-glucose glycerol diether (S 2 -DGD). The G+C content of genomic DNA of the type strain is 62.3 mol%. On the basis of this polyphasic taxonomic study, strain A29 T should be placed in the genus Haloterrigena as a novel species, for which the name Haloterrigena jeotgali sp. nov. is proposed. The type strain of the new species is A29 T (5KCTC 4020 T 5DSM 18794T 5JCM 14585 T 5CECT 7218 T ).Although high salinity is toxic to most cells, extreme halophiles are well adapted to their hypersaline environment (Grant, 2004). Since the establishment of the genus Haloterrigena within the family Halobacteriaceae in 1999 (Ventosa et al., 1999), at the time of writing seven species belonging to it have been described: Abbreviations: S-DGD, mannose-6-sulfate(1-2)-glucose glycerol diether; S 2 -DGD, mannose-2,6-disulfate(1-2)-glucose glycerol diether.The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain A29T is EF077633.Phylogenetic trees based on 16S rRNA gene sequences generated by the minimum-evolution and maximum-parsimony methods, and a thinlayer chromatogram of the polar lipids of strain A29 T and a reference strain (H. thermotolerans PR5 , 1997). Cell morphology was examined using light (Eclipse 80i; Nikon) and electron microscopy (JEM 1010; JEOL). Gram staining was performed as described by Dussault (1955) and motility was examined on semi-solid agar. Optimal conditions for growth were determined in medium 954 containing 0-30 % (w/v) NaCl, and the pH range for growth was assayed from pH 5.0 to 11.0 at intervals of 0.5, and at different temperatures (4, 10, 15, 17, 21, 25, 30, 37, 45, 50 and 60 u C). The Mg 2+ requirement for growth was also determined using medium 954 without MgCl 2 . 6H 2 O and yeast extract. Standard phenotypic tests for indole formation, nitrate reduction, hydrolysis of casein, starch and urea, and activity of oxidase and catalase were conducted as described by Gerhardt et al. (1994). Hydrolysis of gelatin and Tween 80 were tested simultaneously through the procedure adapted for haloarchaea by Gutiérrez & González (1972). Cell lysis in distilled water was detected by microscopic examination. DNase activity was detected on T-Hv agar medium as...

Diversity of Halophilic Archaea in Fermented Foods and Human Intestines and Their Application

“…Halophilic archaea isolated from Korean foods using culture-dependent methods include Haladaptatus cibarius [44], Halalkalicoccus jeotgali [47], Halorubrum cibi [42], Haloterrigena jeotgali [45], and Natronococcus jeotgali [46] from various types of jeotgals, and also Halogranum salarium [23] from bay salt. Their characteristics are shown in Table 1.…”

Features and Applications of Halophilic Archaea

“…In fact, several strains of haloarchaea were isolated from fish sauce: Halobacterium salinarum and Halococcus sp., which reach their maximum densities after 3 or 4 weeks. Moreover, new species, such as Natrinema gari, have been isolated from fish sauce (Tapingkae et al, 2008), Natronococcus jeotgali and Halalkalicoccus jeotgali from other foods, such as shrimp jeotgal (Roh et al, 2007 a,b), and Halobacterium piscisalsi, and Halorubrum cibi from fermented fish (Yachai et al, 2008;Roh et al, 2009).…”

Haloterrigena daqingensis sp. nov., an extremely haloalkaliphilic archaeon isolated from a saline–alkaline soil

“…Previous studies have shown that there are differences in the polar lipid composition among species of the two genera. Haloterrigena species contain the glycolipids S 2 -DGD (Cui et al, 2006;Gutiérrez et al, 2008;MontalvoRodríguez et al, 2000;Roh et al, 2009;Ventosa et al, 1999;Xu et al, 2005b) or mannose-6-sulfate (1A2)-glucose glycerol diether (S-DGD) (Romano et al, 2007), but most Natrinema species have phosphatidylglycerol sulfate and unidentified glycolipids (McGenity et al, 1998; Tapingkae (Kumar et al, 2004). Bootstrap values (%) are based on 1000 replicates and are shown for branches with more than 70 % bootstrap support.…”

“…salina (Gutiérrez et al, 2008) and Htg. jeotgali (Roh et al, 2009). In this study, an aerobic haloalkaliphilic archaeon designated strain JX313 T was isolated.…”