Halobaculum roseum sp. nov., isolated from underground salt deposits

Abstract

Two extremely halophilic archaea, strains D90T and D93, were isolated from underground salt deposits of Yunnan salt mine, China. Both strains were pleomorphic or short rods, non-motile, Gram-negative and required 1.7 M NaCl for growth, with optimum at 3.4 M. Mg2+ was not required for growth. Multiple copies of the 16S rRNA gene were obtained for both strains. Sequence similarity analysis of 16S rRNA genes revealed that strains D90T and D93 were closely related to Halobaculum magnesiiphilum MGY-184T and Halobaculum gomorrense DSM 9297T with the sequence similarity between 96.2-98.1 %. The sequence similarity of the rpoB' gene between strain D90T and Halobaculum gomorrenseJCM 9908T was 94.1 %. The DNA G+C contents of strains D90T and D93 were 65.9 and 67.6 mol%, respectively. The major polar lipids of both strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and glycolipid. The DNA-DNA relatedness value between strains D90T and D93 was 90.1±0.5 %, while that between strain D90T and Halobaculum gomorrenseJCM 9908T was 30.0±0.7 %. The comparison of physiological and biochemical characteristics, including the requirements of NaCl, Mg2+, pH, etc., differentiated strains D90T and D93 from Halobaculum magnesiiphilum MGY-184T and Halobaculum gomorrenseJCM 9908T. Therefore, strains D90T and D93 represent a novel species of the genus Halobaculum, for which the name Halobaculum roseum sp. nov. is proposed. The type strain is D90T (=CGMCC 1.15501T=JCM 31273T).

Halobacterium bonnevillei sp. nov., Halobaculum saliterrae sp. nov. and Halovenus carboxidivorans sp. nov., three novel carbon monoxide-oxidizing Halobacteria from saline crusts and soils

“…WSA2 T and Halovenus sp. WSH3 T are most closely related to Halobacterium noricense A1 T , Halobaculum roseum D90 T and Halovenus aranensis EB27 T with gene sequence identities of 98.71, 98.19 and 95.95 % respectively [20–22]. All sequence identities are at or below the accepted cutoff for 16S rRNA gene-based species differentiation of 98.7–99.1 % [23].…”

Comparative diversity analysis of halophiles at two polar saltern systems in Indramayu, West Java, Indonesia

“…Halobaculum from family Halorubraceae, order Haloferacales, has been isolated from underground salt deposits in Yunnan salt mine, China (Chen et al . 2017). Halobaculum magnesiiphilum sp., a magnesium‐dependent haloarchaeon, has been isolated from sea salt produced in Japan (Shimoshige et al .…”

“…underground salt deposits in Yunnan salt mine, China (Chen et al 2017). Halobaculum magnesiiphilum sp., a magnesium-dependent haloarchaeon, has been isolated from sea salt produced in Japan (Shimoshige et al 2013), and H. gomorrense gen. sp.…”

Salinibaculum litoreum gen. nov., sp. nov., isolated from salted brown alga Laminaria

“…Most halophilic archaea harbour more divergent 16S rRNA gene copies with similarities lower than the recommended threshold (98.7 %) to separate two prokaryotic species [2]. These include species of the Haloarcula–Halomicrobium–Halomicroarcula groups [3, 4], Haloarchaeobius [5], Halobaculum [6], Halomicrococcus [7], Halorientalis [8], Halorubellus [9], Halorussus [10], Halosimplex [11], Halostella [12], Halovenus [13] and Natronoarchaeum [14]. The intragenomic heterogeneity of 16S rRNA genes might be an ancient and stable characteristic in most lineages of the class Halobacteria [15].…”

“…Strain HD8-45 T possessed two copies of 16S rRNA genes, rrn1 (1474 nt, KT261638) and rrn2 (1473 nt, KT261640), which differed in sequence by 8.7 %. The degree of intragenomic variability observed in the 16S rRNA genes is far greater than the average between-species divergence (~1.3 %) [2] and is higher than the most divergence found in Haloarcula (5.6 %) [24], Halomicroarcula (5.1 %) [4], Haloarchaeobius (5.6 %) [5], Halobaculum (4.0 %) [6], Halomicrococcus (3.7 %) [7], Halorientalis (6.9 %) [8], Halorubellus (3.8 %) [9], Halorussus (4.4 %) [10], Halosimplex (7.8 %) [25], Halostella (2.2 %) [12], Halovenus (6.8 %) [13] and Natronoarchaeum (2.2 %) [14]; lower than that in Halomicrobium (9.0 %) [3] which contained the highest 16S rRNA gene divergence in the class Halobacteria . The rrn1 of strain HD8-45 T showed 95.1 % similarity to that of Salinirussus salinus YGH44 T while the rrn2 showed 91.2 % similarity to that of Halovenus aranensis EB27 T ().…”