Инженерно-генетически модифицированные дрожжи Cellusec® сокращают потребность в промышленных ферментах для производства биоэтанола

Abstract Background Cellulase enzyme secretion by cells of 2G S. cerevisiae yeast is considered a promising strategy to reduce the prohibitive cost of commercial cellulase cocktails in lignocellulosic bioethanol production. Here, we have developed Cellusec® strains by engineering enzyme secretion capacity into an industrial lignocellulosic bioethanol strain and demonstrated its potential in simultaneous saccharification and fermentation (SSF) experiments of real-world feedstocks. Results A single copy each of CBHI, CBHII and EG encoding genes, and three copies of a BGL encoding gene were inserted into the strain, followed by overexpression of HAC1i. Importantly, all intermediate strains were evaluated throughout the engineering process, allowing identification of performance trade-offs associated with successive genetic modifications. We show that cell-free supernatant from Cellusec® strains reduced exogenous cellulase cocktail requirements by up to 53% during crystalline cellulose saccharification under low-temperature, enzyme-limited conditions. Under similar conditions, ethanol titers in SSF of cellulosic material obtained from furfural production (furfural residues, FR) were improved by up to 14% in Cellusec® strains, compared to the non-secreting parent. In SSF of pretreated softwood from forestry waste (FW), Cellusec® strains achieved ethanol titers of up to 5.15% (v/v), corresponding to a 25% improvement compared to the non-secreting parent strain. Distinct substrate-dependent synergies were observed between CTec3-HS and the different secreted enzymes. Notably, the recently discovered processive endoglucanase RfGH5_4 was expressed in S. cerevisiae for the first time and showed particularly strong synergy with CTec3-HS in FW SSF. Conclusion These results demonstrate that cellulase-secreting yeast can substantially reduce commercial enzyme requirements in lignocellulosic bioethanol production in SSF setups. They also highlight the importance of tailoring enzyme combinations to specific feedstocks and/or further optimizing cocktails of secreted enzymes. Abbreviations - SSF: - Simultaneous saccharification and fermentation - CBH: - Cellobiohydrolase - EG: - Endoglucanase - BGL: - β-Glucosidase - FR: - Furfural residues - FW: - Forestry waste - CBP: - Consolidated bioprocessing - LCB: - Lignocellulose biomass - DTT: - Dithiothreitol - YP(D): - Yeast extract, peptone, (dextrose) - OD: - Optical density - gRNA: - Guide RNA Acknowledgements We want to thank Stien Veulemans for helping with the execution of the cellobiose fermentation experiments. Funding This work was supported by the Baekeland mandate HBC.2022.0158, funded by Flanders Innovation & entrepreneurship (VLAIO). This work was performed in collaboration with NovelYeast, which additionally provided financial support. Ethics declarations Ethics approval and consent to participate Not applicable. Consent for publication Not applicable. Competing interests The authors declare that this work was performed in collaboration with NovelYeast, which provided financial support and whose employees are co-authors of this study. Additional information Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Supplementary Information Rights and permissions Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. About this article Cite this article Thevelein, B., Demeke, M.M., Desmet, T. et al. Cellulase-secreting yeast can substantially reduce commercial enzyme requirements in lignocellulosic ethanol production. Biotechnol. Biofuels Bioprod. (2026). https://doi.org/10.1186/s13068-026-02810-1 - Received: - Accepted: - Published: - DOI: https://doi.org/10.1186/s13068-026-02810-1