Characterization of bacterial diversity and capacity to remove lead of a consortium from mining soil

Int Microbiol. 2023 Nov;26(4):705-722. doi: 10.1007/s10123-022-00313-1. Epub 2022 Dec 17.

Abstract

Introduction: At present, the presence of lead (Pb2+) continues to be a problem in water bodies due to its continuous use and high toxicity. The aim of this study was to investigate the bacterial diversity of a potential consortium used as a biosorbent for the removal of lead in an aqueous solution.

Methods: The minimum inhibitory concentration and the mean lethal dose of the consortium were determined, and then the optimal variables of pH and temperature for the removal process were obtained. With the optimal conditions, the kinetic behavior was evaluated, and adjustments were made to different mathematical models. A Fourier transform infrared spectroscopy analysis was performed to determine the functional groups of the biomass participating in the removal process, and the diversity of the bacterial consortium was evaluated during Pb2+ removal by an Ion Torrent Personal Genome Machine System.

Results: It was found that the intraparticle diffusion model was the one that described the adsorption kinetics showing a higher rate constant with a higher concentration of Pb2+, while the Langmuir model was that explained the isotherm at 35 °C, defining a maximum adsorption load for the consortium of 54 mg/g. In addition, it was found that Pb2+ modified the diversity and abundance of the bacterial consortium, detecting genera such as Pseudomonas, Enterobacter, Citrobacter, among others.

Conclusions: Thus, it can be concluded that the bacterial consortium from mining soil was a biosorbent with the ability to tolerate high concentrations of Pb2+ exposure. The population dynamics during adsorption showed enrichment of Proteobacteria phyla, with a wide range of bacterial families and genera capable of resisting and removing Pb2+ in solution.

Keywords: Bioadsorption; Biodiversity; Consortium; Lead; Minimum inhibitory concentration.

MeSH terms

  • Adsorption
  • Humans
  • Hydrogen-Ion Concentration
  • Kinetics
  • Lead / analysis
  • Soil*
  • Temperature
  • Water Pollutants, Chemical* / analysis

Substances

  • Soil
  • Lead
  • Water Pollutants, Chemical