Microbial communities and their predictive functional profiles in arid soil of Saudi Arabia
Abstract. Saudi Arabia has world's fifth largest desert and is the biggest importer of food and agricultural products. Understanding soil microbial communities is key to improving agricultural potential of the region. Therefore, soil microbial communities of semi-arid region of Abha known for agriculture and arid regions of Hafr Al-Batin and Muzahmiyah were studied using Illumina sequencing. Microbial community composition varied remarkably from other deserts and from one place to another. Highest diversity was found in rhizospheric soil of Muzahmiyah followed by Abha. Firmicutes, Proteobacteria and Actinobacteria were three main phyla detected in all the samples. Unlike other deserts, Bacteroidetes was not a major constituent and population of Firmicutes was quite high. Soils from agricultural region of Abha were significantly different from other samples in containing only 1 % Firmicutes and three to six times higher population of Actinobacteria and Bacteroidetes, respectively. Presence of photosynthetic bacteria, ammonia oxidizers, and nitrogen fixers along with bacteria capable of surviving on simple and unlikely carbon sources like DMF was indicative of their survival strategies under harsh environmental condition. Functional inference using PICRUSt show abundance of genes involved in photosynthesis and nitrogen fixation. Microbial communities show greater similarity with hot Namib desert than with cold Antarctic desert.