Dr. Ayşegül Öktem
Degrees
Ph.D., University of Groningen, Groningen, The Netherlands
M.S., Middle East Technical University, Molecular Biology and Genetics
B.S., Middle East Technical University, Molecular Biology and Genetics
Research Interests
Microbial cell factories
Cell engineering
Recombinant food enzyme production
Microbial fermentation
Sustainable fermentation techniques
Stress physiology of bacterial systems
Recent Publications
Öktem A., Yokoyama, K., Wu Y., Grilli F., Maaß S., Ishikawa S., Yotsuya M., Sato R., van
Dijl, J. M. *, Yoshida K.* (2026). Effects of breathing vessel culture on enzyme secretion
by a genome-reduced strain of Bacillus subtilis. Microbial Cell Factories. 25(53). https://doi.org/10.1186/s12934-026-02942-x
Yoshida, K., Yokoyama, K., Öktem, A., Ishikawa, S., van Dijl, J. M., Yotsuya, M., & Sato,
R. (2024). Bacillus subtilis grown in a “breathing” vessel without sparger aeration.
Bioscience Biotechnology and Biochemistry. 88(11), 1389-1393.
https://doi.org/10.1093/bbb/zbae120
Aguilar Suárez, R., Kohlstedt, M.*, Öktem, A.*, Neef, J., Wu, Y., Ikeda, K., ... van Dijl,
J. M. (2024). Metabolic profile of the genome-reduced bacillus subtilis strain iig-bs-27-
39: An attractive chassis for recombinant protein production. ACS Synthetic Biology. 13(7), 2199-2214. https://doi.org/10.1021/acssynbio.4c00254
Öktem, A., Pranoto D. A., van Dijl J. M. (2024) Post-translational secretion stress
regulation in Bacillus subtilis is controlled by intra- and extracellular proteases. New
Biotechnology. 79, 71-81. https://doi.org/10.1016/j.nbt.2023.12.009
Öktem A., Núñez-Nepomuceno D., Ferrero-Bordera B., Walgraeve J., Seefried M.,
Gesell-Salazar M., Maaß S., Becher D., Mäder U., Völker U.*, van Dijl J. M.* (2023)
Enhancing bacterial fitness and recombinant enzyme yield by engineering the quality
control protease HtrA of Bacillus subtilis. Microbiology Spectrum. e01778-
23. https://doi.org/10.1128/spectrum.01778-23
Rettenbacher, L. A.*, Arauzo-Aguilera, K.*, Buscajoni, L.*, Castillo-Corujo, A.*, Ferrero-
Bordera, B.*, Kostopoulou, A.*, Moran-Torres, R.*, Núñez-Nepomuceno, D.*, Öktem,
A.*, Palma, A.*, Pisent, B.*, Puricelli, M.*, Schilling, T.*, Tungekar, A. A.*, Walgraeve,
J.*, Humphreys, D., von der Haar, T., Gasser, B., Mattanovich, D., … van Dijl, J. M.
(2022). Microbial protein cell factories fight back? Trends in Biotechnology. 40(5), 576–590. https://doi.org/10.1016/j.tibtech.2021.10.003