Ecological effects of the microbial weathering of silicate minerals

Global climate change is one of the greatest challenges facing humankind in the 21st century. Studying, and utilising, the carbon sink caused by the weathering of silicate minerals has been a key research focus for scholars. The weathering of rocks, especially the chemical weathering of silicate minerals, consumes CO2 by transforming CO2 in the atmosphere or soils to HCO3 which is ultimately deposited as carbonate rocks in the oceans. This means that the weathering of silicate minerals is a net carbon sink, and has been across all time scales (Wofsy et al., 2001) and one which regulates and controls the amount of CO2 in the atmosphere and the associated global climate change (Berner, 1995). The natural weathering of silicate minerals under physical and chemical actions is a slow, passive, process. Organisms, as one of the most active geological agents in the earth-surface system, especially microorganisms, can facilitate the weathering of silicate minerals. In the long-term course of geological evolution, the effect of microorganisms leads to the transfer of CO2 in the atmosphere to carbonate rocks, forming the material basis of karst development and the largest carbon pool in the world (Lian et al., 2011). Weathering of silicate minerals by microorganisms is closely associated with their demand for mineral nutrients. In particular, microorganisms can drive the weathering of silicate minerals to release mineral elements in the environment with poor mineral nutrient levels by regulating their metabolic pathways, which is a physiological metabolism process used to obtaining mineral nutrients (Xiao et al., 2012a). Microorganisms can synthesise and secrete low-molecular-weight organic acids and facilitate the dissolution of minerals through acidification and complexion (Yao et al., 2013). The synergistic effect of *