Cristina Campano
Virender Kumar
María José Fabra
Felice Quartinello- 1Polymer Biotechnology Group, Biological Research Centre Margarita Salas, Spanish National Research Council (CIB-CSIC), Madrid, Spain
- 2Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
- 3Food Safety and Preservation Department, Institute of Agrochemistry and Food Technology (IATA), CSIC, Valencia, Spain
- 4ACIB GmbH, Tulln an der Donau, Austria
- 5Department of Agricultural Sciences, Institute of Environmental Biotechnology, BOKU University, Tulln an der Donau, Austria
Editorial on the Research Topic
Closing the loop: enhancing biotechnological routes for a more circular economy transition
The challenge ahead
The relentless growth of the global population, coupled with rising rates of material and energy consumption, has led to an unprecedented accumulation of solid waste worldwide (Chen et al., 2020). Managing these vast waste streams is not only an environmental necessity but also a pressing socio-economic challenge, as inadequate disposal contributes to pollution, greenhouse gas emissions, and the depletion of natural resources (Singh et al., 2014). Among the different waste categories, municipal solid waste represents one of the most complex and heterogeneous fractions (Voukkali et al., 2024; Zhang et al., 2024). It encompasses diverse materials such as food residues, textiles, fabrics, and synthetic polymers, whose mixed and contaminated nature makes separation, recycling, and valorization particularly difficult (Nanda and Berruti, 2021). This complexity severely limits the effectiveness of conventional waste management strategies and underscores the urgent need for innovative solutions capable of transforming such residues into valuable resources (Campuzano and González-Martínez, 2016; Xiao et al., 2024; Kumar et al., 2025).
Overcoming these challenges requires going beyond traditional recycling practices, which, while essential to a circular economy, are often insufficient to deal with the complexity and heterogeneity of modern waste streams (Awino and Apitz, 2024; Corvellec et al., 2022). To effectively reduce dependence on fossil-based resources, there is a pressing need to develop advanced strategies that combine improved energy and material efficiency with the creation of novel, high-quality bio-based products (Khanna et al., 2024). Such innovations are key to meeting the rising global demand for goods while ensuring environmental sustainability.
In this context, biotechnology represents a powerful driver of the transition towards a circular and resource-efficient economy (Schilling and Weiss, 2021; Vandy et al., 2025). By harnessing advances in bacterial microbiology and enzymatic catalysis, it is now possible to transform heterogeneous waste streams into a wide range of bio-based products, from biofuels to high-performance polymers (Aurand et al., 2024; Torres-León et al., 2021). Recent progress illustrates the breadth of this potential: novel microbial biocatalysts are being identified through OMIC analyses (Hassan et al., 2022; Parveen et al., 2022); innovative enzymatic routes are being developed for polymer recycling (Kumar et al., 2025; Lens-Pechakova, 2021; Zhu et al., 2022) and producing microorganisms or microbial consortia are being refined through metabolic engineering and adaptive laboratory evolution (Guzmán, 2023; Hernández-Herreros et al., 2024; Hirasawa and Maeda, 2022). These advances are complemented by the development and optimization of sustainable bioproduction processes, ultimately paving the way for novel microbial-based value chains that can substitute fossil-derived products (Mihalyi et al., 2024; Pardo et al., 2025). To ensure that these innovations deliver genuine environmental benefits, life cycle analysis (LCA) provides a critical benchmark, allowing bio-based products and processes to be systematically compared with their conventional fossil-based counterparts (Cucurachi et al., 2022). We are convinced that biotechnology will play a central role in enabling this transition, and it is with this perspective that we have curated this Research Topic, whose contributions are summarized in the following sections.
Insights from the Research Topic
The articles included in this Research Topic collectively showcase the breadth of biotechnological approaches being developed to address pressing environmental and societal challenges. They span from enzymatic and microbial strategies for advanced recycling and waste valorization, to biotechnological innovations for renewable energy production, and the discovery of bioactive compounds with therapeutic potential. Together, these contributions highlight how biotechnology through its diverse applications in materials, energy, and health can open new pathways towards a more sustainable and circular bioeconomy. This Research Topic brings together four articles authored by 28 researchers, reflecting the collaborative effort driving progress in the field.
The contributions authored by Siracusa et al. focuses on the biochemical characterization of a novel polyester-hydrolyzing enzyme (Thb) derived from anaerobic Thermoanaerobacterales. This enzyme exhibits a pronounced specificity for aromatic polyesters compared to a well-known benchmark enzyme, revealing distinct potential for targeted polymer degradation. Through comparative analyses—including weight loss measurements and quantification of monomer release the study illuminates how structural differences in Thb underlie its enhanced activity on aromatic substrates. This work exemplifies how microbial catalysts can be leveraged to valorize plastic-rich waste streams and supports the development of more efficient, bio-based waste-to-resource processes.
A second contribution in the enzymatic recycling section of this Research Topic, authored by Egan et al. examines the use of commercial cellulase formulations to enable targeted enzymatic depolymerization of cotton within blended polyester/cotton textiles. By assessing a wide range of enzyme mixtures originally designed for biopolishing, stonewashing, or biomass degradation the study identifies enzyme activity profiles that optimize fiber separation in practical reactor systems. Importantly, the introduction of protein efficiency as a key metric links enzyme performance to economic viability, marking an important step toward scalable, enzyme-based recycling strategies. The results not only advance the scientific understanding of cellulase performance but also provide practical insights into how enzymatic tools can be adapted for more sustainable textile recycling practices.
More in the field of bioenergy, Chawla et al. explores microbial-based strategies to enhance renewable energy generation through the in situ biostimulation of coalbed methane (CBM) wells. Conducted at the Raniganj coal reservoir in India, this research demonstrates that nutrient-induced activation of endogenous microbial communities can quadruple methane production in certain wells. The study further examines how the microbial ecosystem shifts in response, offering insight into the bioconversion pathways at play.
Finally, the study developed by Abdelmalek et al. reports the purification and characterization of two novel protein-based α-amylase inhibitors from Saussurea costus, a medicinal plant traditionally associated with antidiabetic properties. The inhibitors demonstrated strong biochemical stability and inhibitory potency comparable to the standard drug acarbose, together with additional antimicrobial and anticancer activities. By uncovering the therapeutic potential of plant-derived molecules, the study broadens the scope of biotechnology toward health applications and highlights the value of bioprospecting in the circular bioeconomy.
Final reflections
We are confident that this Research Topic will stimulate further research and collaboration at the interface of biotechnology, sustainability, waste management, and health. By bringing together diverse approaches from enzymatic recycling and microbial bioenergy to the discovery of bioactive compounds, this Research Topic reinforces the transformative role of biotechnology in closing the loop and demonstrates its potential to drive innovation toward a truly circular bioeconomy.
Author contributions
CC: Writing – review and editing, Writing – original draft. VK: Writing – review and editing. MF: Writing – review and editing. FQ: Writing – review and editing.
Funding
The author(s) declare that financial support was received for the research and/or publication of this article. Also, editors want to acknowledge funding from the project OPENVIRO (PID2023-146557OB-C21 and PID2023-146557OB-C22), financed by MICIU/AEI/10.13039/501100011033/, H2020 UPLIFT Project by EU (Grant agreement no. 953073).
Acknowledgments
On behalf of the editorial team, we would like to express our sincere gratitude to all the authors who contributed their work to this Research Topic. Their commitment and scientific rigor have been essential to shaping this Research Topic and advancing the dialogue on biotechnology for a circular bioeconomy.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
Generative AI statement
The author(s) declare that Generative AI was used in the creation of this manuscript. The authors used ChatGPT (developed by OpenAI) to assist in improving the readability and language clarity of the manuscript. All content generated by the tool was carefully reviewed, revised, and verified by the authors to ensure accuracy and consistency with the research. Hence, the authors take full responsibility for the content of the publication.
Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
References
Aurand, E. R., Moon, T. S., Buan, N. R., Solomon, K. V., and Köpke, M.EBRC Technical Roadmapping Working Group (2024). Addressing the climate crisis through engineering biology. NPJ Clim. Action 3 (1), 9. doi:10.1038/s44168-023-00089-8
Awino, F. B., and Apitz, S. E. (2024). Solid waste management in the context of the waste hierarchy and circular economy frameworks: an international critical review. Integr. Environ. Assess. Manag. 20 (1), 9–35. doi:10.1002/ieam.4774
Campuzano, R., and González-Martínez, S. (2016). Characteristics of the organic fraction of municipal solid waste and methane production: a review. Waste Manag. 54, 3–12. doi:10.1016/j.wasman.2016.05.016
Chen, D. M. C., Bodirsky, B. L., Krueger, T., Mishra, A., and Popp, A. (2020). The world’s growing municipal solid waste: trends and impacts. Environ. Res. Lett. 15 (7), 074021. doi:10.1088/1748-9326/ab8659
Corvellec, H., Stowell, A. F., and Johansson, N. (2022). Critiques of the circular economy. J. Industrial Ecol. 26 (2), 421–432. doi:10.1111/jiec.13187
Cucurachi, S., Steubing, B., Siebler, F., Navarre, N., Caldeira, C., and Sala, S. (2022). Prospective LCA Methodology for Novel and Emerging Technologies for BIO-Based Products. Luxembourg: Publications Office of the European Union.
Guzmán, L. J. B. (2023). Development of synthetic cooperative consortia using genetic engineering and adaptive laboratory evolution in yeasts. Johann Wolfgang Goethe-Universitaet Frankf. Am. Main. Ger.
Hassan, S., Khurshid, Z., Bhat, S. A., Kumar, V., Ameen, F., Ganai, B. A., et al. (2022). Marine bacteria and omic approaches: a novel and potential repository for bioremediation assessment. J. Appl. Microbiol. 133 (4), 2299–2313. doi:10.1111/jam.15711
Hernández-Herreros, N., Rodríguez, A., Galán, B., and Prieto, M. A. (2024). Boosting hydrogen production in Rhodospirillum rubrum by syngas-driven photoheterotrophic adaptive evolution. Bioresour. Technol. 406, 130972. doi:10.1016/j.biortech.2024.130972
Hirasawa, T., and Maeda, T. (2022). Adaptive laboratory evolution of microorganisms: methodology and application for bioproduction. Microorganisms 11 (1), 92. doi:10.3390/microorganisms11010092
Khanna, M., Zilberman, D., Hochman, G., and Basso, B. (2024). An economic perspective of the circular bioeconomy in the food and agricultural sector. Commun. Earth & Environ. 5 (1), 507. doi:10.1038/s43247-024-01663-6
Kumar, V., Wimmer, R., and Varrone, C. (2025). Efficient bioprocess for mixed PET waste depolymerization using crude cutinase. Polymers 17 (6), 763. doi:10.3390/polym17060763
Lens-Pechakova, L. S. (2021). Recent studies on enzyme-catalysed recycling and biodegradation of synthetic polymers. Adv. Industrial Eng. Polym. Res. 4 (3), 151–158. doi:10.1016/j.aiepr.2021.06.005
Mihalyi, S., Sykacek, E., Campano, C., Hernández-Herreros, N., Rodríguez, A., Mautner, A., et al. (2024). Bio-upcycling of viscose/polyamide textile blends waste to biopolymers and fibers. Resour. Conservation Recycl. 208, 107712. doi:10.1016/j.resconrec.2024.107712
Nanda, S., and Berruti, F. (2021). Municipal solid waste management and landfilling technologies: a review. Environ. Chem. Lett. 19 (2), 1433–1456. doi:10.1007/s10311-020-01100-y
Pardo, I., Manoli, M. T., Capel, S., Calonge-García, A., and Prieto, M. A. (2025). Enzymatic recycling and microbial upcycling for a circular plastics bioeconomy. Curr. Opin. Biotechnol. 93, 103307. doi:10.1016/j.copbio.2025.103307
Parveen, H., Chaudhary, A., Chaudhary, P., Sultana, R., Kumar, G., Khati, P., et al. (2022). “Omics approaches for the production of the microbial enzymes and applications,” in Industrial Applications of Microbial Enzymes (Boca Raton, FL: CRC Press (Taylor & Francis Group)), 317–331.
Schilling, C., and Weiss, S. (2021). A roadmap for industry to harness biotechnology for a more circular economy. New Biotechnol. 60, 9–11. doi:10.1016/j.nbt.2020.08.005
Singh, J., Laurenti, R., Sinha, R., and Frostell, B. (2014). Progress and challenges to the global waste management system. Waste Manag. Res. 32, 800–812. doi:10.1177/0734242x14537868
Torres-León, C., Chávez-González, M. L., Hernández-Almanza, A., Martínez-Medina, G. A., Ramírez-Guzmán, N., Londoño-Hernández, L., et al. (2021). Recent advances on the microbiological and enzymatic processing for conversion of food wastes to valuable bioproducts. Curr. Opin. Food Sci. 38, 40–45. doi:10.1016/j.cofs.2020.11.002
Vandy, J. F., Mohanty, S., and Mohapatra, S. (2025). Biotechnology industry as a catalyst for circular economy in India. Discov. Sustain. 6, 728–26. doi:10.1007/s43621-025-01473-6
Voukkali, I., Papamichael, I., Loizia, P., and Zorpas, A. A. (2024). Urbanization and solid waste production: prospects and challenges. Environ. Sci. Pollut. Res. 31 (12), 17678–17689. doi:10.1007/s11356-023-27670-2
Xiao, N., Kong, L., Wei, M., Hu, X., and Li, O. (2024). Innovations in food waste management: from resource recovery to sustainable solutions. Waste Dispos. Sustain. Energy 6, 401–417. doi:10.1007/s42768-024-00201-6
Zhang, Z., Chen, Z., Zhang, J., Liu, Y., Chen, L., Yang, M., et al. (2024). Municipal solid waste management challenges in developing regions: a comprehensive review and future perspectives for Asia and Africa. Sci. Total Environ. 930, 172794. doi:10.1016/j.scitotenv.2024.172794
Keywords: circular bioeconomy, biotechnology, waste valorization, enzymatic and microbial processes, sustainability
Citation: Campano C, Kumar V, Fabra MJ and Quartinello F (2025) Editorial: Closing the loop: enhancing biotechnological routes for a more circular economy transition. Front. Bioeng. Biotechnol. 13:1697004. doi: 10.3389/fbioe.2025.1697004
Received: 01 September 2025; Accepted: 09 September 2025;
Published: 19 September 2025.
Edited and Reviewed by:
Michael Köpke, LanzaTech, United StatesCopyright © 2025 Campano, Kumar, Fabra and Quartinello. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Cristina Campano, Y3Jpc3RpbmEuY2FtcGFub0BjaWIuY3NpYy5lcw==; Felice Quartinello, ZmVsaWNlLnF1YXJ0aW5lbGxvQGJva3UuYWMuYXQ=