Katrien Claes

After studying Biochemistry and Biotechnology at Ghent University, Katrien Claes obtained a PhD on genetic engineering and recombinant protein production in Pichia pastorisat VIB/Ghent University. She then spent five years in the Microbial R&D division of Lonza in Switzerland, a leading CDMO for protein and biopharmaceutical production. Since returning to VIB in 2020, Katrien Claes is a senior Staff Scientist, overseeing our external collaborations in protein expression technologies and managing a major Gates Foundation grant. Her recent work is particularly associated with the OPENPichia initiative, which has become a widely recognized effort to democratize access to advanced Pichia engineering technologies.

Pichia pastoris (syn. Komagataella phaffii) is widely used for recombinant protein production. However, the commonly used NRRL Y-11430 strain is a patent deposit. Commercial distribution of derived strains during the patent lifetime has been instrumental for the access to and adoption of the Pichia platform. However, as a patent deposit not in the public domain, access to the strain(s) has been encumbered by access restrictions/licensing requirements much beyond the lifetime of the original patent. We developed OPENPichia, an open-access chassis derived from the NCYC 2543 deposit of the Komagataella phaffii type strain, which is genetically almost identical to NRRL Y-11430. Comparative genomics and functional validation revealed that NRRL Y-11430’s high transformability is linked to a truncated HOC1 ORF, affecting cell wall mannan. Introducing this truncation into NCYC 2543 yielded OPENPichia, which matches NRRL Y-11430 in protein secretion and transformability. VIB, provides OPENPichia to the biotech community for a one-time modest fee that serves maintenance and expansion of the OPENPichia resource, along with derivative strains (auxotrophic, protease-deficient, mutS). Additionally, a compatible modular Golden Gate-based vector toolkit was developed and is distributed by Genecorner/BCCM. Together, this allows for royalty-free strain engineering and product development for both academic and industrial users. More details: www.OPENPichia.com.