| Abstract [eng] |
L- and D-lactic acids are an important platform used for the production of various compounds, including biodegradable bioplastics that can replace the traditional petroleum-based polymers. Meanwhile, phenolic acids are significant antioxidants and can be utilized as precursors for the production of other value-added compounds. The fermentation of lactic acids and hydroxycinnamic acids requires strains which can use not only traditional substrates, but also low-cost, non-food alternatives. The transformation of alternative substrates, such as residues or wastes from the agro-food industry, into value-added materials not only ensures efficient production, but it is also an integral part of the circular economy. Pairing an appropriate microorganism to the right substrate is the actual bottleneck requiring the search for strains or the development of genetically modified microorganisms which could efficiently use components of agro-food waste and remain viable in the presence of inhibitors. Rapid and high-throughput analytical methods are required to search for and develop bacterial strains and adapt inexpensive and non-food alternative substrates. Genetically encoded biosensors are an increasingly widely used method that allows rapid characterization of several thousand variants in a short time. This thesis describes the identification and characterization of lactic acids and hydroxycinnamic acids-inducible gene expression systems and their application to the development of genetically encoded biosensors. The biosensors developed in the thesis are adapted to determine L- and D-lactic acids in biological samples with one enantiomer of L- or D-lactic acid or with their mixture. |
