Biotechnology for Lignocellulosic Biomass

The scientific objectives of our group include:

1) Providing knowledge on the biological decay of plant biomass by fungi with special emphasis on lignin biodegradation, a key process for C recycling in nature and the complete exploitation of plant biomass as raw material, as an alternative to the use of fossil resources.

2) Promoting the use of these organisms and their enzymes (improved in the lab by protein engineering, computational design and synthetic biology techniques) for the industrial conversion of renewable plant biomass into bio-based chemicals and/or materials, including the synthesis of bioplastics.

3) Contributing in this way to the concept of Circular (Bio)economy through more sustainable, efficient and clean industrial processes (and with lower carbon footprint) in which organic waste (agricultural, forestry or industrial) is not generated or is used, as well as to the valorization and recycling of oil-derived plastic polymers.

To achieve the above objectives, the first step is unveiling the composition and behaviour of the enzymatic machinery responsible for the transformation of plant biomass by different species of saprophytic fungi. These studies include secretomic, transcriptomic and comparative genomic analyses, complemented with chemical analyses of degraded substrates. Our group has great expertise in oxidoreductase enzymes involved in the biodegradation of the lignin polymer and other aromatic compounds of great biotechnological interest: multicopper oxidases, heme-peroxidases, flavo-oxidases and heme-peroxygenases. Moreover, we carry out phylogenetic and evolutionary studies of all these enzymes, as well as the computational reconstruction and subsequent resurrection and characterization of ancestral enzymes. In this way, we can learn about the changes that each enzyme family has undergone during its evolution, which have given rise to the properties of extant enzymes, providing valuable information for the design of new enzymes as industrial biocatalysts.

The most interesting extant or resurrected enzymes from a biotechnological point of view, expressed in ad hoc herelogous hosts, are subjected to protein engineering through directed evolution and rational design, combined with computational design, to improve their properties or provide the new functionalities required for each specific application. The goal is to apply the new enzymes as biocatalysts in the conversion of plant materials in value-added compounds or in components of bio-based products, developing oxidation and oxyfunctionalization reactions of interest in Green Chemistry, such as those currently investigated in the FurEnPol (PLEC2021-007690), LIG2PLAST (PID2021-126384OB-I00) and OxyLipids (TED2021-129264B) projects, led by our group. More recently, we have started an innovation action funded by the Horizon Europe program and coordinated by our group (ROBUSTOO project, HORIZON-CL6-2023-CIRCBIO-01-101135119, https://www.robustoo.eu), which aims to capitalize on the results of previous EU-funded projects, WoodZymes (https://woodzymes.eu), SusBind (https://susbind.eu), and EnzOx2 (https://www.enzox2.eu). In these projects we had found the applicability of three types of oxidative enzymes, nonspecific peroxygenases (UPO), laccases and hydroxymethylfurfural oxidases (HMFO), to achieve novel and more environmentally friendly production of chemicals and materials from different plant components. To exploit their full industrial potential, ROBUSTOO is developing new, more robust enzymes, adapted to industrial application conditions, and addressing their large-scale production.

Finally, we participate in the CSIC Interdisciplinary Thematic Platform SusPlast on “Sustainable Plastics for a Circular Economy” since its launching, with the aim of contributing with biotechnological solutions to the production of bio-based plastics from renewable sources and the transformation and recycling of petroleum-derived polymers. As part of PTI+ we are responsible for the Pilot Plant for the Design of Enzymatic Biocatalysts.

The activities carried out by our group are aligned with several of the global change challenges proposed in the CSIC 2025 Strategy. In this sense, we actively contribute to finding answers to scientific challenges with a high social impact, such as those included in the ROBUSTOO, LIG2PLAST, OxyLipids and FurEnPol mentioned above. In the same way, our research work is reflected in patents and first-level high-impact international publications, as a result of interdisciplinary collaborations, which have allowed us to consolidate collaborations with national, European and American universities, research centers and companies.