Engineered biofilms have shown tremendous potential in environmental applications, including nutrient removal from wastewater, degradation of persistent pollutants, heavy metal bioremediation, and microbial fuel cells that enable simultaneous treatment and energy recovery. This review presents an unprecedented breadth of recent advances in biofilm engineering for environmental use, highlighting innovations across genetic, material, microbial, and system-level strategies. The objective of this review is to synthesize recent progress in biofilm engineering and qualitatively evaluate the feasibility and limitations of genetic, material, microbial, and reactor-level strategies through a narrative approach. Biofilms are now engineered through genetic modification, material and surface design, bioaugmentation and biostimulation, and reactor optimization. Genetic engineering has transformed biofilm functionality by targeting quorum sensing, extracellular polymeric substance production, electron transfer, and adhesion pathways, enhancing stability, reactivity, and environmental adaptability. Emerging tools, such as optogenetics, modular circuits, and programmable biosensors, offer precise, real-time control over microbial behavior. Advancements in materials, such as hydrogels, nanocomposites, and 3D-printed scaffolds, have improved biofilm structure, integration, and performance. Complementary approaches like smart carrier-supported bioaugmentation and synthetic consortia-based biostimulation have further enhanced biofilm-mediated remediation and energy conversion. At the system level, reactor designs, particularly membrane-aerated systems, play a crucial role in optimizing microbial activity, oxygen transfer, and pollutant contact, underscoring the importance of holistic integration. Despite laboratory successes, key challenges remain in scaling up, ensuring biosafety, and maintaining long-term functionality under real-world conditions. Future efforts should focus on: (1) improving non-invasive gene editing and delivery; (2) validating systems at pilot and full scales; (3) developing multifunctional, biodegradable materials; and (4) advancing interdisciplinary, predictive models. Overall, this review provides a clear roadmap for advancing engineered biofilms from laboratory concepts to practical, safe, and scalable environmental technologies.
Pow‐Seng Yap (2026) studied this question.