| Description |
Bacteriophages as the most abundant biological entities on the planet play a significant role in microbial population dynamics in various ecosystems. The potential of bacteriophages as a driving force in evolution of microbial communities through controlling the bacterial population, naturally selecting phage-resistant bacteria, and facilitating horizontal gene transfer have been studied. However, few studies have demonstrated the effect of phages on the microbial communities in different natural ecosystems, biological nutrient removal reactors, and hypersaline environment. In this study, the role of bacteriophages in functional gene transfer and how they affect different nutrient cycles and bacterial diversity and population in lab-scale and natural ecosystems were investigated. The research was accomplished through studying the bacteriophage population, diversity, and their role in bacterial infection and subsequent alteration in bacterial population and diversity. The ecosystems studied in this study included lab-scale biological phosphorus removal and hypersaline Great Salt Lake as engineered and natural models for understanding the phage-host interaction. The biomass and sediment samples were collected from the lab-scale bioreactor and deep brine layer in Great Salt Lake and subjected to various environmental stress factors to understand the role of bacteriophage and prophage induction in bacterial diversity. In addition, the sediment sample from the Great Salt Lake was analyzed with metagenomics approach. The evaluation of prophage induction showed that various environmental stress factors including nutrients, heavy metals, toxic chemical, and antibiotic can induce phages integrated onto bacterial genomes (i.e. prophages), resulting in a decrease of the bacterial population involved in different nutrient cycles. Analyzing the viral and bacterial metagenomes explored the GC content, oligonucleotide and k-mer profile, genetic homology, CRISPRs, and prophage network. Our in-depth metagenomics analysis identified phage and bacteria communities comprehensively and proved the role of bacteriophages in defining the bacterial community population, diversity, and their effects on various nutrient cycles. Identification of bacteriophage diversity, population, and their functional genes using metagenomics approach in this study will shed light on the bacterial and viral diversity in Great Salt Lake and this information will be helpful in constructing metabolic models to better study the microbial interaction in various hypersaline ecosystems. |
