RELAY: Revalorization of lignin and aromatics in yeast

Carlos del Cerro Sánchez obtained his degree in Biotechnology (2009) at the Pablo de Olavide University (Seville, Spain) and completed his PhD thesis (2015) at the Centro de Investigaciones Biológicas Margarita Salas (CIB, CSIC), where he worked with different synthetic biology and metabolic engineering approaches focusing on environmental biotechnology applications.

After finishing his thesis, he initiated a postdoc stay (2017) at the National Renewable Energy Laboratory (Golden, CO, USA). There he studied different plant biomass revalorization processes to obtain platform chemicals for the production of biofuels and sustainable bioplastics.

In 2022, he returned to the CIB to continue working on waste revalorization using microbial platforms, and since 2023, he is a ComFuturo fellow working in his project RELAY.


El proyecto RELAY tiene por objetivo contribuir a desbloquear el enorme potencial industrial de la lignina, un biopolímero residual generado masivamente en la agricultura y otras actividades, que está infrautilizado a pesar de tener alto potencial de producir productos químicos de valor añadido. El proyecto pretende generar nuevos biocatalizadores basados en levaduras (organismos fácilmente manipulables genéticamente para que actúen como fábricas celulares), capaces de integrar varios pasos de la revalorización de la lignina: su despolimerización seguida de la producción de moléculas que sirvan en última instancia para generar bioplásticos de forma más sostenible. Además se darán los primeros pasos para su escalado industrial. Por tanto, este proyecto representa una novedosa aproximación biotecnológica para reciclar los residuos de lignina, contribuyendo así a un modelo de economía circular.
The RELAY project aims to contribute to unlocking the enormous industrial potential of lignin, a waste biopolymer massively generated in agriculture and other activities, which is under-utilised despite its high potential to produce value-added chemicals. The project aims to generate new biocatalysts based on yeasts (organisms that can be easily genetically manipulated to act as cell factories), capable of integrating several steps of lignin revalorisation: its depolymerisation followed by the production of molecules that ultimately serve to generate bioplastics in a more sustainable way. In addition, the first steps will be taken towards industrial scale-up. This project therefore represents a novel biotechnological approach to recycling lignin waste, thus contributing to a circular economy model.

Extended project summary:

The transition to environmentally friendly, circular economy models is an urgent need in our societies. For this reason, efficient waste management is key to get closer to more sustainable lifestyles that can help to stop global warming.

Plant biomass waste can be found as residues from different production activities, for example, agriculture or pulp and paper industry. Due to its woody properties, this biomass is difficult to process and transform. This is mainly due to the presence of lignin, a very abundant and complex polymer that confers rigidity to the plant and whose biological degradation in an industrial context implies an important technological challenge.

For this reason, the main goal of the RELAY project is to generate a new generation of biocatalysts capable of depolymerizing lignin and transforming the resulting monomers in molecules that can be used to produce more sustainable bioplastics and polymers. To do this, the brewer’s yeast Saccharomyces cerevisiae, an ancient biotechnological tool, will be used. This microbe has been chosen due to its great versatility, that allows merging fungal and bacterial functions in a single biological platform. For this reason, S. cerevisiae will be genetically manipulated to expand its metabolic capabilities, combining the lignin depolymerization properties of other fungi and bacterial metabolic pathways related to the degradation of aromatic compounds. Thus, starting from lignin, we will produce chemicals of interest that can be used to produce nylon or bioplastics with similar properties related to polyester. Additionally, these yeast-based biocatalysts will be adapted to large-scale conditions to improve their future industrial performance.

The implementation of this new lignin recycling technology could integrate several steps of the current lignin revalorization process in a single biocatalyst, stablishing a biorefinery that can produce green biopolymers without depending on petroleum-based feedstocks.