Comparative molecular analysis of the prokaryotic diversity of two salt mine soils in southwest China

Abstract

While much is known about the microbial diversity in some hypersaline environments, little is known about those of salt mine tunnel soils. The objective of this study was to conduct a comprehensive phylogenetic comparison of the archaeal and bacterial communities present in Yipinglang salt mine (YPL) and Qiaohou salt mine (QH) tunnels differing in salinity and salt composition using 16S rRNA gene clone libraries. Two hundred twenty-eight sequences for QH and 182 sequences for YPL were analyzed by amplified ribosomal DNA-restriction analysis. Libraries revealed 44 bacterial and 57 archaeal different operational taxonomic units belonging to at least 8 bacterial and 3 archaeal divisions, but not all divisions were observed in both salt mines. The bacterial community affiliated with the Bacteroidetes was the most abundant (60% of clones) in QH, while the community in YPL was dominated by δ-Proteobacteria (45% of clones). All archaeal clones from QH were affiliated with Halobacteriaceae. In contrast, in the YPL library, 49% of clones belonged to Halobacteriaceae, 31% of clones related to unclassified archaea, and 21% of clones belonged to Crenarchaeota. Bioinformatic analysis and comparisons showed that the clone libraries were significantly different between two salt mines.

Polyploidy in Archaea and Bacteria: About Desiccation Resistance, Giant Cell Size, Long-Term Survival, Enforcement by a Eukaryotic Host and Additional Aspects

“…Isolation of haloarchaeal clones has been reported from sites that have been thought to be occluded from outside contact for several hundred thousand or even millions of years [e.g. Fendrihan et al, 2012;Gramain et al, 2011;Gruber et al, 2004;Park et al, 2009;Schubert et al, 2010;Stan- Lotter et al, 2002;Vreeland et al, 1998;Xiao et al, 2013]. Several reviews discuss the arguments in favor and against the possibility of long-term survival [Fendrihan et al, 2009;Grant et al, 1998;Stan-Lotter, 2004].…”

Polyploidy in haloarchaea: advantages for growth and survival

“…It has repeatedly been reported that haloarchaea have been isolated from ancient salt deposits that had remained undisturbed for geological times (e.g., Fendrihan et al, 2006; Park et al, 2009; Schubert et al, 2010; Gramain et al, 2011; Xiao et al, 2013). The salt deposits are in different parts of the world and have different ages, and the isolations were performed by several different research groups.…”

Trehalose/2-sulfotrehalose biosynthesis and glycine-betaine uptake are widely spread mechanisms for osmoadaptation in the Halobacteriales

“…In addition to their prevalence in hypersaline habitats, members of the Halobacteriales are also consistently observed in saline (10-17% NaCl) environments as a fraction of a more complex halophilic and halotolerant prokaryotic and eukaryotic population (Bowman et al, 2000;Perreault et al, 2007;Stivaletta et al, 2011;Youssef et al, 2012;Xiao et al, 2013). Further, members of the Halobacteriales have also been identified as a minor constituent of the microbial population in lowsalinity environments including sea water (Ventosa et al, 1984), seawater aquarium (Inoue et al, 2011), anaerobic springs (Elshahed et al, 2004), low salinity salterns (Mani et al, 2012), coastal salt marshes (Munson et al, 1997, Purdy et al, 2004, and hydrothermal (Takai et al, 2001) and geothermal (Ellis et al, 2008) vents, where pockets of salinity occasionally develop.…”