Advances in bacterial synthesis pathways of bioflocculants and their applications in mine wastewater treatment.

Microbial flocculants represent environmentally friendly alternatives to chemical flocculants and serve a pivotal role in mine wastewater remediation. Despite extensive research efforts on bioflocculant-based mine wastewater treatment, insufficient understanding of their biosynthetic mechanisms has hindered the practical application of bioflocculants. In this review, we summarize that the production efficiency and flocculating activity of bioflocculants are closely regulated by a range of environmental factors and metabolic pathways. Divalent and trivalent metal ions significantly enhance flocculating activity, whereas monovalent ions exert only a weak regulatory effect. Additionally, most bioflocculant-producing strains exhibit optimal growth at 20–30 °C and pH 7.0–9.0. The biosynthetic pathways and key regulatory genes of bioflocculants, which govern the synthesis of core components, directly determine their pollutant removal capacities, establishing an intrinsic link between molecular synthesis and practical mine wastewater remediation. Furthermore, this review addresses critical bottlenecks limiting industrial application and proposes targeted solutions, including directed breeding of high-yield strains, utilization of low-cost agricultural and industrial wastes as fermentation substrates, and AI-integrated metabolic regulation strategies. This work fills the gap in research on the molecular mechanisms of bacterial bioflocculants and provides a theoretical foundation for the efficient development and industrialization of bioflocculants for mine wastewater remediation.