Contrasted microbial community colonization of a bauxite residue deposit marked by a complex geochemical context

Potential of Ligand-Promoted Dissolution at Mild pH for the Selective Recovery of Rare Earth Elements in Bauxite Residues

“…In addition, the use of organic molecules produced by living organisms will also be explored. It includes highly selective organic molecules produced specifically to recover REEs by methylotroph bacteria such as lanmodulin − but also other molecules produced by plants, bacteria, or fungi than are known to dissolve phosphates and/or REEs in soil (siderophores, − formic acid, succinic acid, malic acid, amino acids...). ,,− In this regard a better knowledge of plants and microorganisms developing in BR deposits may be particularly informative for selecting appropriate bio-inspired extraction strategies. − …”

Decades of weathering improves coal waste biogeochemical properties by altering dissolved organic matter and microbial communities: A case‐study of a coal waste pile

“…In comparison, the geochemical conditions of the 10‐year weathered coal waste characterized by pH 4.1, EC 1.9 mS cm −1 , and 60.3% large particles (2–0.5 mm) create hostile environments for most domains of life. Recently, studies by Ke et al (2021) and Macias‐Perez et al (2022) showed that long‐term natural weathering facilitated the improvement in physicochemical properties and microbial community development of wastes in tailing storage areas. In line with these previous studies, our results suggest that interactions between environmental factors and microbial communities driven by natural weathering‐induced organic matter degradation provide microorganisms‐ and plant‐relevant nutrients (e.g., organic carbon and available N and P) and thus facilitate microorganism development.…”

“…Recent studies have also revealed that most phyla of bacterial communities in coal are Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria, while revegetation promotes the relative abundance of Bacteroidetes, Proteobacteria, Nitrospirae, Chloroflexi, and Verrucomicrobia in coal mining activity areas (Cao et al, 2020; Jiang et al, 2021; Wang et al, 2019). We speculated that this may be attributed to the phyla Actinobacteria, Proteobacteria, and Firmicutes, which contain some of the prokaryotes that are best adapted to high salinity and extreme environments (Macias‐Perez et al, 2022). In addition, an increase in the relative abundance of Actinomycetes, the predominant bacteria in coal waste, is beneficial for organic matter degradation through surface aerobic effects (Hamamura et al, 2006; Kanokratana et al, 2011).…”

“…Actinobacteriota and Bacteroidota were identified as keystone species in coal waste samples and were negatively correlated with TOC and BIX (characterized as microbial autogenous source organic components), indicating their relevance in oligotrophic habitats and potential to become key species (Foreman et al, 2007; Gonzalez‐Pimentel et al, 2018). The main sources of TOC in the early stages were atmospheric exogenous organic matter and carbon fixed by autotrophic microbial species (Ciccazzo et al, 2015; Macias‐Perez et al, 2022). Hodkinson et al (2002) emphasized the positive role of heterotrophic communities in microbial assembly, degradation of organic matter, and provision of nutrients (e.g., C, N, and P) for the subsequent development of autotrophic species in the early stage of primary succession.…”

“…In comparison, the geochemical conditions of the 10-year weathered coal waste characterized by pH 4.1, EC 1.9 mS cm À1 , and 60.3% large particles (2-0.5 mm) create hostile environments for most domains of life. Recently, studies by Ke et al (2021) and Macias-Perez et al (2022) showed that long-term natural weathering facilitated the improvement in physicochemical properties and microbial community development of wastes in tailing storage areas.…”