In the phylogenetic tree from saline
soils, OTUs from cluster 3 (9 OTUs and 32 clones), cluster 5 (12, 32), cluster 6 (3, 13), cluster 7 (6, 15) and cluster 8 (2, 6) grouped with cbbL sequences of known cultured organisms like Rhodopseudomonas palustris, Oligotropha carboxidovorans, Nitrosospira, Rhizobium leguminosarum, Salinisphaera, Alcaligenes, Pelomonas, Paracoccus, Rhodobacter, Volasertib Agrobacterium tumefaciens, Sinorhizobium fredii and Ochrobactrum anthropi (79-88%). The cbbL sequences in the cluster 4 (8, 20) were grouped with Aurantimonas bacterium (4 OTUs), Methylocapsa acidiphila (one OTU), Bradyrhizobium japonicum (one OTU) and Azospirillum lipoferum (one OTU). Some sequences in the cluster 5 displayed sequence homology with Nitrosospira. Phylotype HS154 was distantly related with Sulfobacillus acidophilus and Mycobacterium. Cluster 1 (12, 35, 2 cultured isolates) showed a high intra cluster similarity not affiliated with any other known RuBisCO sequence and formed a monophyletic lineage with cbbL sequences of the cultured isolates (HSC14, RSC22) obtained from these soil samples. The phylotype R13 from saline soil constituted a distinct branching lineage not affiliated with any known cbbL containing cultured representative. The form IA cbbL genes were amplified only from high saline
soil (SS2). The phylogenetic analysis (Figure 1) revealed that the 8 phylotypes (28 clones) were not closely associated with known sulphide, ammonia oxidizers or other taxa and formed one separate monophyletic cluster. Furthermore, the form C646 molecular weight IA clone sequence RG42 was divergent from other form IA gene sequences. 16S rRNA clone library and phylogenetic analysis Total 329 16S rRNA gene clone sequences were retrieved from three soil samples. The RDP classifier was used to assign 16S rRNA gene sequences to the phylogenetic groups (Figure 3). Totally 227 OTUs were identified among the 329 clones nearly in the combined data set. PKC inhibitor Comparative abundance of these OTUs was illustrated by heatmap (Additional file 1: Figure S1) generated by Mothur.
A total of 147 clone sequences were analyzed from the agricultural soil (AS), which generated 109 unique OTUs that grouped within ten bacterial phyla- Proteobacteria (Alpha, Beta, Gamma, and Delta), Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Gemmatimonadetes, Nitrospira and Planctomycetes. A total of 97 and 85 gene sequences were analyzed from saline soils (SS1 & SS2) which generated 55 and 63 unique OTUs respectively. These OTUs grouped into different bacterial phyla as described above except Cyanobacteria and Nitrospira. The phylogenetic trees showing the taxonomic assignment of phylotypes to different bacterial groups were constructed from the three soil clone libraries (data not shown).