Cultivation of microorganisms from sulfidic mine waste and genomic insights into acidibacillus ferrooxidans and penicillium sp

Abstract

With increasing pressure to support sustainable mining initiatives, the advancement of biotechnologies is essential for dealing with mine waste in Canada and around the world. These improvements require a thorough understanding of microorganisms that inhabit different waste materials. This study used classic culturing techniques to isolate acidophilic ironoxidizing bacteria and genomic sequencing to characterize microbial isolates from different source materials. Two organisms were isolated from an enrichment culture that was inoculated with low-sulfur waste rock from a Canadian mine site. They were identified as a strain of Acidibacillus ferrooxidans and a fungus of the genus Penicillium. Some of the genes that were annotated from the sequenced prokaryotic genome were absent in available genomes of Ab. ferrooxidans and others were associated with metabolic abilities that have not been described in this organism, such as respiratory nitrate reduction. A total of 59 stress response genes were identified including for resistance to several heavy metals and multiple antibiotics. Fungal biomass displayed iron oxidation as well as accumulation, and 4 genes encoding for multicopper oxidase enzymes were annotated which have been associated with the adaptation of fungi in metal-rich environments. This study also tailored selective media with the aim of isolating bacteria from the genera Leptospirillum and Sulfobacillus from sulfidic bioreactor cultures. These groups were not identified but we started to isolate at least 2 different colonies of interest. This project provides insight into microorganisms from these waste materials and their potential in biotechnologies. It also emphasizes the importance of assessing fungi in these environments.