Ewa Żymanczyk-Duda
Wroclaw University of Science and Technology, Poland
Title: Microbial bioconversions of biologically active P-C compounds: Scope and limitations of scaling-up
Biography
Biography: Ewa Żymanczyk-Duda
Abstract
Chirality is a crucial feature in the world of living organisms. This is responsible for the specific interactions between biologically active compounds in nature; therefore, it is also fundamental for designing the novel compounds. Among P-C compounds, structures are phosphonate derivatives such as amino phosphonates, keto phosphonates, hydroxy phosphonates. These are analogues of physiological compounds, so they are applied as moderators of activity of particular enzymes involved in natural compounds metabolic pathways. For such purposes, it is necessary to receive them as defined optical isomers. Chemical synthesis of such phosphonates is of low-effectiveness, also for the economic reasons, so biocatalytical approach appeared to be a good alternative. Good results were achieved for the kinetic resolutions of the racemic mixtures of amino- and hydroxy-phosphonates. This was performed via selective oxidation and employing following fungal genera: Penicillium, Beauveria, Cunninghamella, Verticillium, Cladosporium, Rhodotorula and Saccharomyces (as whole-cells biocatalysts). The same fungal mycelia were able to selectively reduce (thermodynamic process) prochiral keto phosphonates. The above mentioned experiments succeeded based on the laboratory scale and the most effective ones were selected for scaling- up process. This was the hardest part, because it required the modifications of the biotransformation procedures and the biocatalyst form. Experiments were performed with the use of batch and continuous reactors, and the fungal mycelia were immobilized with the use of polyurethane foams.