Biotechnology seminar

Thank you for all joining the last Biotechnology seminar! Next week, on October 1st, we have two more exciting talks, and as always in the Seminarrum 3130-303 from 12.00 to 13.00.

We will be happy to welcome Professor Eyal Zussmann, who will discuss how protein-based materials can be engineered into nanofibers, with potential applications in tissue engineering and cultured meat. Afterwards, PostDoc Jamie Lustermans will take us to the limits of microscopy and microbial physiology, exploring cable bacteria, extracellular electron transfer, and innovative imaging techniques.

Speaker: Professor Eyal Zussmann

Title:

Overcoming Rheological and Structural Challenges in Additive Manufacturing of Proteinaceous-Based Structures

Abstract:

The versatile molecular structures and biological functions of proteins make them highly valuable building blocks in biotechnology and medicine. Although proteins can self-assemble into supramolecular structures, their relatively weak physical interactions lead to shorter lifespans compared to chemically cross-linked materials. Enhancing the stability of these supramolecular assemblies requires strategies to modulate intermolecular interaction strengths. In this talk, we provide an overview of research on assembling proteins using electrospinning to generate fibers with orientational order. Continuous fiber formation requires jet stabilization via sufficient solution viscoelasticity; however, native proteins typically retain rigid secondary or tertiary structures, preventing the intermolecular entanglements needed to establish a global network (Lauricella 2020; Martin 2024; Martin 2025). A common strategy to introduce viscoelasticity is blending the protein with a secondary carrier polymer. Alternatively, unfolding proteins into linear-like chains can impart the required rheological properties, albeit often at the expense of using toxic solvents (Dror 2008). To overcome these limitations, we focus on developing supramolecular networks by bridging proteins with oppositely charged, weak polyelectrolyte macromolecules (e.g., polysaccharides) (Martin 2019; Warwar 2022). We demonstrate the formation of a global network and the electrospinning of these protein-polyelectrolyte complexes into nanofibers under strong electric fields. Finally, we discuss the mechanical properties and stimuli-responsive tunability of these nanofibers, highlighting their potential applications in tissue engineering and cultured meat (Levi, 2026; Kabha, 2021).

References

Dror, Y., et al. (2008), Nanofibers made of globular proteins. Biomacromolecules, 2749–2754.

Lauricella, M., et al. (2020), Models of polymer solutions in electrified jets and solution blowing. Reviews of Modern Physics, 035004.

Martin, P., et al. (2019), pH Controlled Network Formation in a Mixture of Oppositely Charged Cellulose Nanocrystals and Poly(allylamine). J. Polym. Sci. Part B Polym. Phys., 1527–1536.

Martin, P. et al. (2024), Charge transport in electrospinning of polyelectrolyte solutions. Soft Matter, 5572-5582.

Martin, P., et al. (2025), Capillary Self-thinning of Threads of Polyelectrolyte Solutions with Axial Electric Fields. Proceedings of the National Academy of Sciences, e2422879122.

S. Levi, S. et al. (2026), Not just a protein source: Chickpea protein-based scaffolds for cultured meat. Food Hydrocolloids, 111847.

Kabha, A. et al. (2021), Biodegradable Controlled Release Device for Localized Chemotherapeutic Treatment of Bladder Cancer. ACS Biomaterials Science & Engineering, 2548-2557.

Speaker: PostDoc Jamie Lustermans

Title:
Pushing the limits of microscopy and microbial physiology

Abstract:

Fluorescence microscopy has a clear limit, which is why we cannot identify cellular structures smaller than 200 nm. This pushes people towards electron microscopy, which gives beautifully detailed resolution, but in terms of labelling it often leaves much to be desired. Cleverly designed sample preparation, to overcome this, is used to perform expansion microscopy: we expanded centimeters-long multicellular bacterial filaments that are capable of electron transfer. Cable bacteria, that are grown exclusively in sediment, have very strong conductive fibers that were previously only visible with electron microscopy. In that sediment, there is an electric community from which we described a new species that is capable of extra-cellular electron transfer to anodes. This has always been assumed to be an exclusively anaerobic process, yet Microbacterium deferens is capable of dual breathing. Other isolates from this community can make sturdy biofilms that may be used to assist Sporomusa ovata to stick better to the cathode to more effectively make acetate.

You’ll be sure to stick around for these two talks, supplied with coffee and cake!