Characterisation of bacterial communities from an active mining site and assessment of its potential metal solubilising activity. Issue 6 (December 2020)

• Record Type: Journal Article
• Authors: Lopes, Ana Rita; Madureira, Diana; Diaz, Ana; Santos, Sílvia; Vila, Maria Cristina; Nunes, Olga Cristina
• Is Part Of: Journal of environmental chemical engineering. Volume 8:Issue 6(2020)
• Publication Date: 2020-12
• Subjects: Neutrophile-sulphur-oxidising-bacteria -- Chemolithoautotrophs -- Chemolithoheterotrophs -- Metal solubilisation -- Arsenic -- Acid mine drainage; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2020.104495
• Languages: English
• ISSNs: 2213-2929

Abstract

Graphical abstract: Highlights: Bacterial communities were recovered from sulphide ore from an active mine. Feed, tailings and paste samples were collected at three independent times. Neutrophile sulphur-oxidising chemolithoautotrophs were the most abundant. Mixotrophs and facultative lithoheterotrophs/organoheterotrophs were also present. Tailings' bacterial community solubilised different noxious metal(loid)s. Abstract: The present work is the first report characterising bacterial communities recovered from sulphide ore from a Portuguese active mine (Neves-Corvo) and collecting samples from three independent processing stages (feed/tailings/paste), at three sampling periods over 15 months. The recovered bacterial communities demonstrated low richness and heterogeneity (intra/inter-samples). Neutrophile sulphur-oxidising chemolithoautotrophs (e.g., Thiobacillus, Halothiobacillus, Thiomicrospira ) were the most abundant organisms found across all samples. The presence of these primary producers may explain the occurrence of mixotrophs and facultative chemolithoheterotrophs/chemoorganoheterotrophs (e.g., Limnobacter, Paracoccus, Marinobacter, Alishewanella, Pseudomonas ) in these non-acidic (4.6 < pH> 8.7), pyrite-rich environments. The capacity of the surviving bacterial community following ore processing (tailings) to solubilise metals from mine wastes was also assessed. After 65 days at room temperature and in the presence of thiosulphate as an additional energy source, the tailings' bacterial community solubilised pollutants detected in acid mine drainage waters, namely As (96%), Cd (58%), Cu (24%) and Zn (56%) with the concomitant decrease of pH from 7.4 to 1.8. The low solubilisation efficiencies obtained for copper, zinc, and cadmium indicate a limited technological potential of these communities. However, their ability to significantly mobilise noxious pollutants from the mine wastes to the liquid medium, particularly for As, raises environmental concern. This finding should increase awareness among stakeholders for the need to increase studies at field scale, in real scenarios.