Insights on comparative bacterial diversity between different arid zones of Cholistan Desert, Pakistan

The present study was conducted to analyze bacterial diversity profile of Cholistan desert located in Pakistan. The study investigates the influence of physicochemical parameters of soil on distribution of different bacteria at all taxonomic levels and also study the distribution pattern between different desert environments, particularly rhizospheric and bulk desert sands. Species richness showed phyla Proteobacteria and Chloroflexi as the dominant OTUs in all the samples. Besides the two phyla, the rhizospheric soils with root remnants were dominated by Firmicutes, Deinococcus-Thermus, Actinobacteria and Acidobacteri, while phylum Thermotogae was present in significant quantity in rhizosheaths devoid of roots. In non-rhizospheric desert soils, a considerable number of OTUs belonged to phyla Proteobacteria, Chloroflexi, Bacteroidetes and Acidobacteria. An important finding from this study is that a bulk portion of the OTUs were assigned to unclassified taxa, indicating a large repertoire of unexplored taxa in the desert ecology of Pakistan. Distribution of taxonomic groups among various regions of the desert was collaborating well with the physicochemical parameters of the sites. The findings of this study establish the fundamental relationships between desert ecosystem, specific native plant and the total bacterial flora. This is the first study of microbial community analysis of any desert in Pakistan and thus, will serve as a future platform to explore further on desert ecosystem functioning by employing the ever-changing biotechnological tools.