Characterization of Heavy Metal Resistance Genes from a Cryptic Plasmid of Pseudomonas B0623, Isolated from the Deep Subsurface of Savannah River, Ga

Abstract

Pseudomonas sp. B0623 was obtained from the Savannah River Site, a nuclear reservation in South Carolina that is highly contaminated with heavy metals. The bacterial isolates are therefore expected to contain heavy metal resistance genes that allow them to survive in a contaminated environment. Among all those bacterial isolates, the strain B0623 was cultured, its plasmid DNA was extracted and purified using a plasmid extraction kit and long-read whole genome sequencing was performed using Pac-Bio sequencing. After quality control checks, assembly was performed using the program Canu within the Cyverse Discovery Environment, which allowed 7.2 million reads to be assembled into 20,636 contigs. Visualization of the resulting assembly graph in the program Bandage revealed that 3 plasmids were assembled precisely during assembly, and at least 5 plasmids were likely present in Pseudomonas sp B0623. CyVerse and RAST were used to annotate the largest plasmid, and the RAST output file was screened for presence of metal resistance genes.