C5 Biological Route: Solar-to-Isoprene
C5 develops a next-generation, fully biological Solar-to-x platform capable of converting sunlight, water, and CO2 directly into isoprene, a valuable industrial molecule.
Solar-to-X technologies aim to use sunlight to convert simple molecules like water and CO2 into valuable fuels and chemicals, but current approaches still face major hurdles: they often have low efficiency, require large amounts of energy, rely on expensive or rare materials, and suffer from rapid performance loss. Even biological routes struggle with slow reaction rates and toxic intermediates.
By improving CO2 fixation, creating a catalysis enhancing synthetic organelle for key reactions, and simplifying product recovery, C5 offers a more sustainable, scalable, and cost-effective path toward clean Solar-to-X chemical production.
Scientific Innovations
C5 integrates three major scientific breakthroughs. Each solves a long-standing bottleneck in biological Solar-to-X systems
GED Cycle: A More Efficient CO2-Fixation Engine
The Calvin–Benson–Bassham (CBB) cycle, driven by Rubisco, is globally important yet inherently inefficient: Rubisco is slow, wastes energy through oxygenation, and requires high ATP input.
C5 replaces this bottleneck with the GED cycle, a synthetic carbon fixation pathway that offers an about 30% more energy efficient route for converting CO2 into useful molecules. Additionally, it has the potential to accelerate photosynthetic CO2 fixation by 2-3 fold. C5 installs this cycle into in the fast-growing cyanobacterium Synechococcus so it can operate faster and more efficiently.
Target
Successfully install a fully functional GED cycle in cyanobacteria — something never achieved before.
Synthetic Organelle for Compartmentalized Metabolism
Compartmentalization creates a microenvironment that protects the cyanobacteria’cytosol from toxic intermediates, maintains favorable metabolite gradients and overall boosts carbon flux toward the selected pathway.
In C5 the synthetic organelle is the is the engine room where the most energy-saving steps (the GED cycle) and the most toxic steps of the isoprene production are co-localized to make the whole process faster and more efficient
Target
High-catalytic rates for targeted reactions within the synthetic organelle variants (best permeability profile).
A Direct CO2 to Isoprene Pipeline
Conventional microbial cell factories must synthesize sugars/starch/glycogen and then break them down again to produce chemicals — an energetically expensive detour.
C5 eliminates these inefficiencies by directly producing isoprene, which spontaneously volatilizes and separates from cells and media.
Target
Isoprene recovery at 99% efficiency and >90% purity