Microbial Systems and Protein Engineering

The growth and diversification of the research lines of the "Biotechnology for lignocellulosic biomass" group has led to the creation of this new group, structured around two main lines. Our common goal is focused on the bioconversion of natural or artificial waste by enzymes or whole microbial cells. Drs. Mª Jesús Martínez and Alicia Prieto lead studies on hydrolytic enzymes involved in the degradation and transformation of carbohydrates and lipids of the plant cell wall. On the other hand, Dr. Jorge Barriuso has initiated a promising research line centered on the use of fungi, bacteria, or microbial consortia, exploring the formation of catalytic biofilms and the cooperation between species mediated by quorum sensing mechanisms.

From the pillars of basic knowledge, our team wants to contribute to the establishment of clean bioprocesses based on the use of secondary raw materials (e.g., agro-industrial and plastic waste) for the sustainable development of society. Our research is aimed to reduce the consumption of fossil resources and global warming, the development of clean and non-polluting bioprocesses, and the elimination and exploitation of waste in accordance with the concepts of biorefinery and circular economy.

The group's extensive experience in the discovery and molecular, biochemical, and kinetic characterization of native and recombinant fungal hydrolases has made it possible to improve their catalytic properties, through protein engineering, for specific applications. Regarding the use of microorganisms in complex biotransformations, microbial strains are selected based on their enzymatic and metabolic arsenal, and then for their ability to degrade specific substrates and produce value-added compounds, create consortia, form catalytic biofilms, and establish cooperative relationships through quorum sensing mechanisms. The individual and detailed study of these aspects is crucial to find biotechnological solutions to some of the great social challenges.

In all our projects, biocatalysis aims to replace polluting processes, producing, in some cases, compounds that are impossible to obtain chemically, contributing to the development of sustainable processes. The most relevant applications addressed so far are related to the enzymatic production of second and third generation biofuels and value-added products, such as prebiotic oligosaccharides, bioactive derivatives of lipids or sugars, aromas, and flavorings. Among the most recent findings, the production of bioplastics (PHAs) from lignocellulosic waste using microbial consortia stands out, which gave rise to a patent, transferred to a company, and the creation of the spin-off Microbial Biosystems S.L.

The group also participates in two Interdisciplinary Thematic Platforms (PTI) of the CSIC: i) "Sustainable Plastics for a Circular Economy" (SusPlast), started in March 2019, whose objective is to develop research and innovation activities focused on production processes of plastics and their recycling. In this sense, several current projects focus on the production of bioplastics (PLA, PHAs, PEF) from renewable sources and the efficient degradation of conventional plastics (PE, PET) through biotechnological strategies; ii) PTI+TransEner (Green Energy and Hydrogen Production Program) which, in collaboration with the industrial sector, will develop knowledge that promotes the energy transition. This new platform aims to make a qualitative and quantitative leap in the CSIC's capacity to develop renewable and sustainable biofuel production technologies for maritime and air transport. Within the framework of this platform, a plant will be built at the CIB to produce, on a pilot scale, second-generation ethanol from lignocellulosic waste.

We also participate in the European research infrastructure IBISBA, whose objective is to provide access to a network of laboratories that accelerate the implementation of Synthetic Biology and White Biotechnology in the development of industrial bioprocesses and represents the preparatory phase of a European ESFRI.

Crystal structure of a fungal versatile sterol esterase/lipase which catalyzes efficiently esterification and transesterification reactions