Teaching the biocatalysis cycle using iterative design of L-proline biotransformation into <i>trans</i> -4-hydroxy-L-proline as a paradigm of molecular biotechnology

Biocatalysis is an exceptionally fascinating scientific discipline, offering solutions to numerous persistent global challenges. While nature provides a generous wealth of biocatalysts, scientists and engineers have the unique ability to harness and optimize their performance for specific applications. The development of a biocatalytic process is guided by a conceptual framework known as the biocatalysis cycle, an iterative and cyclical workflow encompassing design, synthesis, and analysis. These interconnected phases not only allow researchers to gain a deep understanding of the system but also enable integrative improvements across multiple levels. In this study, we present a course designed for master’s students in biochemistry, biotechnology, and related fields that encompasses the integrative and iterative nature of the cycle, from strain engineering, reaction design and product purification to process modelling and techno-economic analysis. The biotransformation of L-proline to trans-4-hydroxy-L-proline using recombinant Escherichia coli cells as whole-cell biocatalysts serves as an exemplary case study. The work highlights the necessity for a dynamic and integrated collaboration across multidisciplinary scientific fields, as well as for a vigorous interplay between academia and industry. Furthermore, this study envisages to communicate the cumulative effort invested by many scientists over a decade in establishing the trans-4-hydroxy-L-proline production by engineered Escherichia coli as a robust educational platform able to effectively convey the fundamental principles of the biocatalysis cycle to students in Molecular Biotechnology, fostering both conceptual understanding and practical insight.