Bioprocess development and optimization

The BIOSYSTEMS group carries out research in Bioprocess Engineering, with the main purpose of developing and optimizing biotechnological applications of non-conventional yeast and filamentous fungi. Under this goal different microbial cell cultivation strategies are studied, such as the use of high pressure bioreactors, airlift bioreactors, submerged and solid-state fermentation, and the use of immobilized cells.
Main topics of the team research work are:

Biotechnological application of Yarrowia lipolytica

Yarrowia lipolytica is an aerobic, eukaryotic, non-pathogenic and dimorphic microorganism, being one of the most studied “non-conventional” yeast species, with enormous potential of industrial application. This yeast is been explored by the team for many applications such as lipases, organic acids and aroma (γ-decalactone) production from castor oil. In this last example, culture medium is an oil-in-water emulsion that has been used as a model system for mass transfer phenomena characterization using different types of bioreactors, STR and airlift.

Strategies of oxygen transfer rate improvement to microbial cultures: hyperbaric bioreactors

Hyperbaric bioreactors operating at increased, air or other gas, total pressure are important tools to increase gas components solubility in the culture medium, thus improving mass transfer rate. These bioreactors have been used by the team for many aerobic bioprocesses, such as homologous and heterologous proteins production by several yeast species. Cell physiology under increased pressure has been characterized, mimicking the cellular behavior under stress conditions that may occur in high-scale bioreactors.

Up-grading of agro-industrial wastes

Bioprocess development based in low-cost substrates is one major pursuit of the team. The main objective is to give a competitive solution for the biotechnological industry to re-use wastes as feedstock, improve biotechnological processes by the use of more efficient resources, greener and more competitive technologies. In this context, crude glycerol from the biodiesel industry has been explored for the production of organic acids (ex. citric acid) by Yarrowia lipolytica. This yeast and other species of Candida have also been used due to the ability to grow on olive mill wastewaters and to produce enzymes from it. Mixtures of solid wastes such as pomaces from the wine and olive oil industry are been used in solid-state fermentation by Aspergillus spp to produce enzymes such as lipases, celullases, xilanases, among others.