Waste Biomass Biorefining as Pivotal Strategy in Circular Bioeconomy

Waste biomass biorefining is an important area of research for advancing the circular bioeconomy and replacing linear production models based on resource extraction, manufacturing, and disposal. Agro-industrial effluents, food and municipal waste, microalgae, biodiesel by-products, and synthesis gas represent abundant and underutilized feedstocks for producing fuels, platform chemicals, solvents, and food and cosmetic ingredients. However, their heterogeneous composition, seasonal availability, contaminants, and structural recalcitrance continue to limit efficient conversion. Recent studies have demonstrated progress in biomass pretreatment, microbial strain improvement, metabolic engineering, mixed microbial cultures, and integrated fermentation systems. Nevertheless, challenges remain in achieving reliable feedstock utilization, high product yields, process stability, economic viability, and reduced environmental impacts at industrial scale. Further investigation is needed to connect advances in biotechnology and process engineering with commercially sustainable biorefinery strategies.This Research Topic aims to advance the development of sustainable and commercially viable processes for converting waste biomass into industrially relevant, high-value products. It will address how pretreatment, microbial engineering, fermentation design, and bioreactor development can improve the accessibility and utilization of complex waste feedstocks. Contributions may investigate strategies for increasing product yield, productivity, and selectivity; enhancing microbial tolerance and substrate range; establishing stable and synergistic microbial consortia; and reducing energy, chemical, and water consumption. The Research Topic will also consider how emerging technologies, including microbial electrolysis cells, can be integrated into fermentation and biorefinery platforms. Research addressing process scalability, techno-economic performance, life-cycle impacts, and alignment with circular economy principles is particularly encouraged.To gather further insights into the biological and engineering approaches for converting diverse waste biomass feedstocks into value-added products, this Research Topic will focus on sustainable processes from feedstock preparation through fermentation and bioreactor operation, while considering their scalability, economic feasibility, and environmental performance. We welcome articles addressing, but not limited to, the following themes:\n\n- Sustainable pretreatment technologies for reducing biomass recalcitrance and improving substrate accessibility\n- Valorization of agro-industrial effluents, food waste, municipal waste, microalgae, biodiesel by-products, and synthesis gas\n- Microbial strain improvement and metabolic engineering for efficient waste-feedstock conversion\n- Development and optimization of microbial consortia for feedstock degradation and product formation\n- Microbial production of biofuels, platform chemicals, solvents, and food and cosmetic additives\n- Optimization of culture conditions, nutrient strategies, and fermentation parameters\n- Fermentation modes, process intensification, and bioreactor configuration\n- Fermentation process monitoring, control, and downstream processing\n- Integration of microbial electrolysis cells and other emerging bioprocess technologies\n- Techno-economic assessment, life-cycle assessment, and industrial scale-up of waste biomass biorefineries Topic editors: Roberto Mazzoli, Valeria Reginatto Spiller, Simone Morra, Esther Trigueros Source: https://www.frontiersin.org/research-topics/83920/waste-biomass-biorefining-as-pivotal-strategy-in-circular-bioeconomy