Soil microorganisms are involved in mineral weathering, nutrient bioavailability, and bioremediation in the soil ecosystem. In this regard, microbes' mineral interactions can assist exogenic biogeochemical reactions. Various microorganisms cause weathering and rock decomposition through biocorrosion, bioerosion, and bioperforation by inhabiting rock surfaces or crevices (Bin et al., 2008). Microbes acquire nutrients from rock surfaces by building complex organic ligands and encouraging the release of mineral elements. Bioperforation in rock surface by microbial colonization promotes the exposed surface area of rock and intensifies its weathering by mechanical erosion, microbial destruction, and deterioration of rock particle cementation structure (Ehrlich, 1998). Microorganisms also boost mineral weathering through acidification by producing organic acids, microbial water retention, and release of CO₂ due to microbial respiration (Chen et al., 2000). Microorganisms enhance mineral availability from geological resources through mineral breakdown and rock deterioration. Furthermore, microbial technology exploits low-grade mineral resources available for plant uptake, accelerating soil formation (Kumar et al., 2018).

Microorganisms promote soil physicochemical characteristics and nutrient cycling in soil solution (Li et al., 2006). Roots exudates facilitate mineral solubilizing microorganisms (MSM) to perform their activity. In response to the plant's nutritional needs, exudation rates increase with root surface area (Aoki et al., 2012). In addition, plants emit sugars, amino acids, enzymes, fatty acids, sterols, growth factors, vitamins, and secondary metabolites. They transform the rhizosphere into a nutrient-rich environment that may support a diverse microbial population (Vives-Peris et al., 2020). The MSM in the rhizospheric area promotes a more intense mineral bioavailability than bulk soil. Microorganisms solubilize insoluble minerals through various mechanisms, including direct dissolution, redox reactions, and enzymatic production of various acid phosphatases and phytases (Kumar et al., 2013). They solubilize minerals from the soil directly through microbial weathering and promote plant growth by improving root development, modulating phytohormones, producing siderophores and hydrogen cyanide, increasing plant enzymatic activities, controlling phytopathogen under normal as well as stress conditions (Mumtaz et al., 2017; Etesami and Adl, 2020; Saeed et al., 2021).

Industrialization in the current era negatively affects soil and crop productivity by accumulating vast amounts of minerals, including heavy metals. These heavy metals are cytotoxic even at low concentrations and cause human cancer. Their toxicity causes higher production of reactive oxygen species that reduce the antioxidant systems and affect an organism's normal functioning, ultimately leading to cell death (Tarfeen et al., 2022). The MSM can perform bioremediation of contaminated agricultural soil. These microorganisms perform bioremediation of metal minerals through biosorption to cell walls, precipitation, capturing in extracellular capsules, efflux outside the cell, transformation of metal minerals to a less toxic state, and ligation inside cell leading to adsorption of metal minerals ions (Riseh et al., 2022). Bioremediation of metal minerals depends on environmental factors (temperature, pH, electron acceptor, nutrients, etc.), contaminant properties, biodegradative genes in organisms, and bioavailability of contaminants to degrading microorganisms within the site (Maier, 2000). In the current Research Topic, metal bioavailability was considered to be the most crucial factor in bioremediation. The bioavailability of minerals also has a vital role in rocks and minerals weathering and nutrient availability for crop growth and productivity. The MSM have biologically activated metabolic systems that are eco-friendly and cost-effective and have various mechanisms for weathering, bioavailability, and bioremediation of minerals.

This Research Topic aims to uncover the role of MSM in mineral weathering, nutrient availability, and bioremediation. This topic presents two reviews and four original research papers by 39 authors from seven countries that span the research on mineral-solubilizing microorganisms. This topic publishes one article on weathering, three articles on nutrient bioavailability and plant growth promotion, and two articles on the bioremediation or recovery of metal minerals. These articles give insight into ongoing issues and provide a basis for further study on the application of MSM in nutrient availability and bioremediation. Here, we summarized some highlights from the six articles published on this Research Topic.