Natronococcus roseus sp. nov., a haloalkaliphilic archaeon from a hypersaline lake

Abstract

A novel halophilic archaeon, strain CG-1 T , belonging to the genus Natronococcus was isolated from sediment of the soda lake Chagannor in Inner Mongolia, China. The colonies of this strain were pink pigmented, the intensity of the colour decreased when the cells grew at salt saturation levels. The cells were non-motile cocci and strictly aerobic. Hypotonic treatment did not cause cell lysis, even in distilled water. Strain CG-1 T grew at 15-30.0 % (w/v) NaCl and at 30-50 6C and pH 8.0-11.0, with optimal growth occurring at 25-30 % (w/v) NaCl, 37-45 6C and pH 9-9.5. , phylogenetically the most closely related species, was 39 %; this value showed that strain CG-1 T constituted a different genospecies. The comparison of 16S rRNA gene sequences, detailed phenotypic characterization, polar lipid profile and DNA-DNA hybridization studies revealed that strain CG-1 T belongs to the genus Natronococcus and constitutes a novel species for which the name Natronococcus roseus sp. nov. is proposed. The type strain is CG-1Members of the family Halobacteriaceae, the single family recognized within the order Halobacteriales, have long been identified as the most abundant micro-organisms in hypersaline environments (Oren, 1994). At the time of writing, the family Halobacteriaceae comprises 34 genera (Euzéby, 2011). The genus Natronococcus was established by Tindall et al. (1984) and currently it contains three species, two of which are haloalkaliphilic: the type species of the genus Natronococcus occultus (Tindall et al., 1984) and Natronococcus amylolyticus (Kanai et al., 1995), while Natronococcus jeotgali is alkalitolerant (Roh et al., 2007).The first two species were isolated from the soda lake Magadi and the last one from shrimp jeotgal, a traditional fermented food from Korea. The genus Natronococcus is distinguished because the cells are cocci and are found in irregular clusters, pairs or single cells. Members of the genus are non-motile, Gram-variable, strictly aerobic and able to reduce nitrate to nitrite. They grow at salt concentrations between 8 and 30 % (w/v) NaCl [optimum at 22 %, (w/v) NaCl], at a pH range of 8.5-11.0 (optimum at pH 9.5) and a temperature range of 20-50 u C (optimum at 40 u C). The DNA G+C content for the major chromosome is 64.0 mol%, while the minor component has a content of 55.7 mol% (Tindall et al., 1984).In the present study, we have characterized strain CG-1 T , isolated from sediment of the soda lake Chagannor located in Inner Mongolia, China. Based on the 16S rRNA gene sequence analysis, polar lipid determination and phenotypic characteristics, strain CG-1 T is closely related to members of the genus Natronococcus.Strain CG-1 T was isolated from a sediment sample from the soda Lake Chagannor (43 u 219 130 N, 11 u 089 630 E) located in Inner Mongolia Autonomous Region, China. At the time of sampling, the water of the lake had a temperature of 17.1 u C, the pH was 9.5, the conductivity 21.3 mS cm 21 and the salinity 16 % (Grant et al., 2011). Approximately 0.5 g of the sediment sample was...

Halorubrum halodurans sp. nov., an extremely halophilic archaeon isolated from a hypersaline lake

“…5626; 10620 cm); the plates were eluted in the solvent system chloroform/90 % methanol/acetic acid (65 : 4 : 35, by vol.) (Angelini et al, 2012;Corral et al, 2013). To detect all polar lipids, the plate was sprayed with sulfuric acid, 5 % in water, and charred by heating at 160 8C (Kates, 1986).…”

“…5626; 10620 cm); the plates were eluted in the solvent system chloroform/90 % methanol/acetic acid (65 : 4 : 35, by vol.) (Angelini et al, 2012;Corral et al, 2013). To detect all polar lipids, the plate was sprayed with sulfuric acid, 5 % in water, and charred by heating at 160 8C (Kates, 1986 appear as purple spots and the remaining polar lipids as brown spots after prolonged heating; alternatively, the plate was sprayed with a solution of primuline and lipids were detected upon excitation by UV light (336 nm) (Fuchs et al, 2007).…”

Adaptive strategies in the double-extremophilic prokaryotes inhabiting soda lakes

“…Active uptake of compatible solutes and their precursors is documented both in Archaea and Bacteria (13). Additionally, compatible solutes are synthesized de novo, predominantly as 2-sulfotrehalose in alkaliphilic haloarchaea and glycine betaine, ectoine, among others, in haloalkaliphiles and natronophiles (14). transporters (cation/proton antiporters -CPAs, Na + / solute symporters, among others) [21 ,37].…”

Systematics of haloarchaea and biotechnological potential of their hydrolytic enzymes

“…The strain grows optimally at 3.5-3.6 M NaCl and 35-40 C. Ncc. roseus (isolated from a hypersaline lake, China) [169], Ncc. jeotgali (isolated from Korean fermented food) [25] and Ncc.…”