Analysis of amplified 16S rRNA gene sequences was done in comparison with the RDP II database (match length >1200 nucleotides). The percentages of the phylogenetically classified sequences are plotted on y-axis. The detailed affiliation of different phylotypes with their closest neighbour in database is presented in Additional file 4: Table S1. The majority of phylotypes that belong to Alphaproteobacteria were from AS clone library. These OTUs were related (85-99%) to Rhizobiales, Sphingomonadales and Rhodospirillales while six OTUs from SS1 & SS2 libraries showed affiliation (89-99%)

to Rhodobacterales, Rhizobiales and Rhodospirillales. A cluster of 25 sequences from AS clone library (7 OTUs), which contributes 58.7% of the total AS Betaproteobacterial population were related (87-99%) to Limnobacter thiooxidans from family Burkholderiaceae, formed one of its largest cluster. The only SS1 OTU HSS79 showed 97% similarity BVD-523 cost to uncultured Betaproteobacteria whereas no OTU was observed in SS2 clone library. The 22 OTUs (4 from www.selleckchem.com/products/ABT-888.html AS and 18 from SS1 & SS2 clone libraries) were related to different species of uncultured Gammaproteobacteria. Most of the SS1 & SS2 clone sequences were related to cultured bacteria like Salinisphaeraceae bacterium, Methylohalomonas lacus, sulphur-oxidizing bacterium and Marinobacter

species. The presence of sulphur-oxidizing and Marinobacter bacteria PFKL in saline soils may suggest the presence of sulphur in these saline environments. These saline soils

indeed contain sulphur (Table 1). Deltaproteobacterial OTUs from SS1 & SS2 clone libraries formed a tight cluster with deep sea bacterium, uncultured Deltaproteobacteria and Marinobacterium. OTUs belonging to photoautotrophic Cyanobacteria and chemoautotrophic nitrifying Nitrospira were found only in AS clone library. Two phylotypes BSS159 and BSS49 were related (91%) to Cyanobacteria and uncultured Nitrospira, respectively and more may be present as rarefaction curves did not reached saturation, although started to level off. The photoautotrophic Chloroflexi related sequences were mostly from SS1 & SS2 clone libraries within the families Caldilineaceae, Sphaerobacteraceae and Anaerolineaceae. One OTU RS187 had 88% homology with Sphaerobacter thermophilus, no other OTUs were more than 91% similar to that of any described organism (Additional file 4: Table S1). There were only two OTUs from AS clone library which showed affiliation (>92%) to uncultured Chloroflexi. van der Meer et al. (2005) [27] suggested that Cyanobacteria and Chloroflexi utilize different spectra of light, and CO2 from the atmosphere for photosynthesis. Firmicutes related sequences were found mostly in AS and SS2 clone library. One phylotype RS190 was affiliated with Bacillus polygoni (95%) a moderately halophilic, non-motile, obligate alkaliphile isolated from indigo balls.