About This Project

Biomanufacturing of recombinant proteins in cell culture yields high value for biomedical applications but is costly and resource intensive. We have established a unique class of buoyant protein nanobubbles engineered to display binding peptides to select for protein targets, effectively creating a self-isolating affinity resin. Here, we propose to engineer Cyanobacteria as a sustainable, low resource biomanufacturing platform to unlock a new paradigm for producing these protein nanobubbles.

Ask the Scientists

What is the context of this research?

In biomanufacturing of recombinant proteins, purification has the most significant impact on cost, accessibility and sustainability (1, 2). Affinity chromatography has the highest fidelity (3) and 25% of the market share among purification technologies (4) in this multi-billion dollar market (5). However, traditional affinity resins require ecologically costly heavy metals (e.g. Ni-NTA beads) or selective protein-based binders (e.g. Protein A/G) that are sourced from a separate biomanufacturing process and chemically immobilized onto a solid support (6). There is an urgent need to develop sustainable and low-cost purification tools for protein biomanufacturing (7), to decouple market growth from ecological impact.

What is the significance of this project?

Gas vesicles (GVs) are genetically encodable, buoyant protein-shelled nanobubbles with emerging potential in biotechnology (8). We have recombinantly expressed engineered GVs in E. coli to display affinity tags and demonstrated their utility as buoyant “beads” for protein purification. Pre-translational modification of GVs yields a purely protein-based product, forgoing chemical modification and simplifying the production process, but GV production in E. coli is resource intensive with low yields. Certain species of photosynthetic cyanobacteria natively produce high yields of GVs on minimal resources – light, CO₂, N₂ and minerals. Enabling genetic engineering of GVs directly in these Cyanobacteria could provide a paradigm shift in protein biomanufacturing (9).

What are the goals of the project?

The current understanding of Cyanobacterial culture and genetic engineering lags behind established systems such as E. coli and key species of Cyanobacteria which are competent GV producers are not genetically tractable. We will address this in two sub goals:
A. We will develop a pipeline for the genetic engineering of a GV-competent Cyanobacterial species, enabling us to leverage and augment its native GV production capacities and establish it as a sustainable biomanufacturing platform for engineered GVs.
B. We will establish culturing of these Cyanobacteria in flexible, 100-liter scale bioreactors to harvest sustainably produced GVs and perform biochemical and functional validation to ensure we meet the needs of the growing biotech industry.