Investigating the impact of fly ash contamination on soil microbial diversity: a metagenomic study near Kolaghat Thermal Power Plant, India

Abstract

Soil metagenomics using whole genome shotgun sequencing (WGS) uncovers microbial diversity and functionality in soils. This study aimed to explore microbial diversity and functional adaptation in soils exposed to fly ash near the Kolaghat Thermal Power Plant, West Bengal, India, using whole genome shotgun sequencing. Understanding how microbial communities respond to such contamination is essential for developing effective bioremediation strategies. Soil samples were collected from the area, designated as BP1 sample selected for detailed metagenomics analysis. The study extracted DNA with a concentration of 46.2 ng/µl, followed by quality checks and profiling to identify microbial communities. Analysis showed that bacterial communities were dominated by Actinobacteria (48.28%) and Proteobacteria (40.80%), while fungi were primarily represented by Ascomycota (89.50%). Among viruses, Negarnaviricota were most prevalent, with the class Insthoviricetes accounting for 94.60%. Diversity analysis indicated that bacterial populations remained stable, fungal diversity fluctuated, and viral diversity increased, reflecting complex ecological interactions. The presence of key genes involved in lipid and carbohydrate metabolism suggests that microbes adapted to contamination by heavy metals and organic pollutants. The dominance of stress-tolerant Proteobacteria and Actinobacteria highlights their potential role in bioremediation. Future research should explore the potential of these microbes, particularly the role of ABC transporters, in improving pollutant degradation.

Keywords: Actinobacteria; Bioremediation; Fly ash; Metagenomics analysis; Microbial diversity; Proteobacteria; Whole genome shotgun.