Rapid urban expansion has intensified the challenges associated with waste generation, resource consumption, and environmental degradation, prompting cities to seek sustainable and technologically robust solutions. Microorganisms, with their remarkable metabolic versatility, are emerging as central agents in biotechnological strategies aimed at transforming urban waste management. This review highlights the significance of microbial innovations in improving waste treatment processes and supporting sustainable urban development. Microbes play a pivotal role in the decomposition, conversion, and detoxification of diverse waste streams, including organic refuse, sewage, industrial effluents, and solid municipal waste. Through biotechnological interventions such as composting, anaerobic digestion, bioremediation, and bioenergy production, microbial systems not only reduce waste volumes but also generate valuable by-products such as biogas, biofertilizers, and treated water suitable for reuse. Advances in molecular biology, metabolic engineering, and microbial ecology have further strengthened these applications by enabling the selection, modification, and optimisation of microbial strains for specific environmental functions. Engineered microbial consortia, for example, are now capable of enhancing the breakdown of complex pollutants, improving the efficiency of wastewater treatment plants, and supporting circular economy principles within urban settings. These innovations contribute significantly to lowering greenhouse gas emissions, reducing landfill dependency, and improving public health by minimising exposure to untreated waste. The integration of microbial technologies into urban planning aligns with the broader vision of smart and sustainable cities. When combined with digital tools such as real-time monitoring, automated waste sorting systems, and data-driven environmental management, microbial biotechnology offers a resilient and adaptable framework for addressing modern urban challenges. The paper concludes that microbial innovations, supported by appropriate policy, investment, and community participation, have the potential to reshape waste management systems and foster long-term urban sustainability.
*Dr. Renuka G. (Sat,) studied this question.