Microbial communities in mine waste- contaminated soil of Sub-Saharan Africa: potential application for...

In recent years, mining activities have increased significantly across SSA (Sub-Saharan Africa), leading to adverse environmental and health impacts. Our review examined diverse microbiota inhabiting various types of mine waste in SSA, emphasizing their natural adaptive mechanisms to withstand extreme conditions. We highlighted key gaps and directions for future studies to support the use of mine waste-resistant microorganisms in ecoremediation efforts. A comprehensive literature search was conducted using reputable online databases to cover studies published between January 2010 and 2024 for information synthesis. Our analysis has revealed microbial communities mainly comprising Proteobacteria (33%), Firmicutes (22%), Actinobacteria (12%), and Acidobacteria (4.1%) of all reported microbial phyla, along with other microbial phyla such as Nitrospirae, Bacteroidetes and Ascomycota distributed across different mine-impacted ecosystems in SSA. The mine wastes reported in this study primarily consist of metals and metalloids (66.7%), followed by oil and hydrocarbons (16%), coal (6.3%), salt (6.2%), and smaller portions of rare metals, and phosphate, each accounting for 1.6%. Microbial species within these phyla exhibit the ability to thrive in polluted environments due to their inherent capacity to metabolize, degrade, and transform toxic compounds, thereby facilitating natural attenuation. However, technical, scientific, operational, implementation, regulatory, and economic challenges hinder bioremediation practices in SSA. Despite these challenges, the region offers significant opportunities that can serve as the foundation for overcoming such constraints. To support scalable and sustainable bioremediation, it is essential to conduct pilot studies focusing on indigenous microbes, alongside systemic monitoring to assess progress and optimize outcomes over time in bioremediation efforts.