Comparative metagenomic analysis of bacterial diversity in three distantly related soils in India

Soil microbial diversity is a vital factor for the progression of vegetation and biogeochemical cycles in an ecosystem. It is affected by the chemical composition, soil microenvironment and anthropogenic activities. The present study investigated the effect of environmental conditions and anthropogenic activities on the bacterial diversity of three distantly related soils in India. The multiple soil samples were collected from Hospital waste sites (BTC2) with extensive anthropogenic activity, Himalayan forest soil (RM1) with low anthropogenic activity and Tso Kar Lake sediment soil samples with negligible anthropogenic activity with environmental factors such as soil pH, temperature and altitude on the bacterial diversity. The soil samples were analyzed for physico-chemical properties that suggest significant variations in pH, electrical conductivity (EC), total dissolved solids (TDS), temperature and altitude. The SEM-EDS (Scanning electron microscopy with energy-dispersive X-ray spectroscopy) analysis revealed the elemental composition of the soil samples. The bacterial diversity of three different soil samples was studied using 16S rRNA sequencing-based metagenomic analysis. The results suggested that the bacterial diversity in Hospital waste site soil samples was higher than in the other two soil samples based on chao1 (richness and evenness) analysis. The Phyla Firmicutes were more abundant in Hospital waste site soil, and Himalayan forest soil showed a higher abundance of phylum Proteobacteria (28.86%) and Actinobacteria (26.70%). Tso Kar Lake sediment soil samples showed the most abundant phylum as Proteobacteria (46.28%). The study suggests that increased anthropogenic activity increases soil bacterial diversity. It may eventually help to develop new approaches for sustainable land-use management practices.