This review explores the microbial strategies for degrading low-concentration substrates in aquatic ecosystems, emphasizing their role in sustainable remediation solutions. Microorganisms adapt to low-concentration environments through various mechanisms, including substrate concentration, uptake, and metabolic pathways. They develop strategies at both the cell and aggregate levels to concentrate substrates, such as carbon, nitrogen, and sulfur, and form biofilms to enhance resource utilization. Microbial metabolic pathways, such as mixed-substrate utilization, syntrophic metabolism, and dynamic responses to nutrient variation, enable efficient substrate degradation. These strategies are crucial for managing emerging contaminants, such as micropollutants, and contribute to achieving sustainable development goals (SDGs) related to clean water, sustainable cities, climate action, and life below water. Understanding and leveraging these microbial strategies can enhance bioremediation techniques and promote the sustainability of water ecosystems.This review explores the microbial strategies for degrading low-concentration substrates in aquatic ecosystems, emphasizing their role in sustainable remediation solutions. Microorganisms adapt to low-concentration environments through various mechanisms, including substrate concentration, uptake, and metabolic pathways. They develop strategies at both the cell and aggregate levels to concentrate substrates, such as carbon, nitrogen, and sulfur, and form biofilms to enhance resource utilization. Microbial metabolic pathways, such as mixed-substrate utilization, syntrophic metabolism, and dynamic responses to nutrient variation, enable efficient substrate degradation. These strategies are crucial for managing emerging contaminants, such as micropollutants, and contribute to achieving sustainable development goals (SDGs) related to clean water, sustainable cities, climate action, and life below water. Understanding and leveraging these microbial strategies can enhance bioremediation techniques and promote the sustainability of water ecosystems.