Identification and Metabolism of Naturally Prevailing Microorganisms in Zinc and Copper Mineral Processing

Abstract

It has only recently been discovered that naturally prevailing microorganisms have a notable role in flotation in addition to chemical process parameters and overall water quality. This study’s aim was to assess the prevailing microbial communities in relation to process chemistry in a zinc and copper mineral flotation plant. Due to the limitations of cultivation-based microbial methods that detect only a fraction of the total microbial diversity, DNA-based methods were utilised. However, it was discovered that the DNA extraction methods need to be improved for these environments with high mineral particle content. Microbial communities and metabolism were studied with quantitative PCR and amplicon sequencing of bacterial, archaeal and fungal marker genes and shotgun sequencing. Bacteria dominated the microbial communities, but in addition, both archaea and fungi were present. The predominant bacterial metabolism included versatile sulfur compound oxidation. Putative Thiovirga sp. dominated in the zinc plant and the water circuit samples, whereas Thiobacillus spp. dominated the copper plant. Halothiobacillus spp. were also an apparent part of the community in all samples. Nitrogen metabolism was more related to assimilatory than dissimilatory nitrate and nitrite oxidation/reduction reactions. Abundance of heavy metal resistance genes emphasized the adaptation and competitive edge of the core microbiome in these extreme conditions compared to microorganisms freshly entering the process.

Applying EDTA in Chelating Excess Metal Ions to Improve Downstream DNA Recovery from Mine Tailings for Long-Read Amplicon Sequencing of Acidophilic Fungi Communities

“…For example, Malassezia and Spegazzinia were observed only in YSM S2 and Scoleobasidium , which was unique to GYEM. The genus Malassezia has been reported in flotation tailings of the Kevitsa mine in Finland [ 58 ] and in zinc and copper tailings [ 59 ]. Because the genus is known to dominate parts of the human microbiota [ 60 ], it was suggested by Miettinen et al [ 59 ] that its presence in tailing samples may have come as result of human contamination.…”

“…The genus Malassezia has been reported in flotation tailings of the Kevitsa mine in Finland [ 58 ] and in zinc and copper tailings [ 59 ]. Because the genus is known to dominate parts of the human microbiota [ 60 ], it was suggested by Miettinen et al [ 59 ] that its presence in tailing samples may have come as result of human contamination. However, ecological information from FungalTraits assigned Malassezia as a soil saprotroph that is associated with plant roots.…”

Prokaryotic communities in the historic silver mine Reiche Zeche

“…Likewise, sequences belonging to the phylum Thaumarchaota in sample BFRZ6b could not be specified further than up to the ammonium oxidizing Candidatus Nitrosotaleaceae (part of minor phyla). The occurrence of this Candidatus family was shown in mine-impacted habitats and is discussed as important group for nitrification in low pH environments (Herbold et al 2017 ; Gavrilov et al 2019 ; Miettinen et al 2021 ).…”

Anode Modification with Fe2O3 Affects the Anode Microbiome and Improves Energy Generation in Microbial Fuel Cells Powered by Wastewater

“…shows good resistance to high metal concentrations; however, our study indicates that, although Fe presence favors Thiovirga sp. growth in anodic biofilm, this genus prefers lower Fe concentrations in the environment [79,80]. Longilinea sp.…”