Microalgae are photosynthetic microbes which offer the potential for the production of various high value products (HVP) such as pigments, proteins, lipids, and bio-active compounds.
We developped an advanced RP production and secretion system for the green unicellular model alga Chlamydomonas reinhardtii. The versatile expression vector employs the secretion signal of the C. reinhardtii carbonic anhydrase for efficient RP secretion into the culture medium. Unique restriction sites allow fast and easy sub-cloning of sequences of interest. Positive transformants can rapidly be identified by high-throughput plate-level screens via a coupled Gaussia luciferase marker. Compared to the native secretion signal of the Gaussia luciferase, up to 84% higher RP production could be achieved. The target RP is found exclusively in culture medium and can therefore easily be isolated and purified.
Recombinant protein expression & secretion, detected by luminescence
Terpenoids, also known as isoprenoids or terpenes, are structurally and functionally diverse hydrocarbons which have many natural roles including pigmentation, electron transport, membrane fluidity, signalling, and wound response. Through serial condensation of 5 carbon containing building blocks, arrays of natural terpenoids are chemically made in a modular fashion by an enzyme class known as the terpene synthases. Their natural diversity has lead to use of these compounds in food and feed, medicine, fragrance, and biofuel applications. The largest source of industrially and medically relevant terpenoid metabolites are higher plants. The expression of terpene synthases in biotechnological microbial hosts allows the transfer of valuable terpenoid production from native plants into controllable and containable production systems. Microbial terpenoid production provides reliable yields in contained cultivation, circumventing the need to harvest potentially rare natural sources of the desired product. Microalgal cells are naturally terpenoid rich, containing numerous natural terpenoid pigment molecules. We investigate the capacity of microalgae to act as hosts for photosynthetic-microbial style production of terpenoid products by transferring terpenoid synthases from higher plants into microalgae. The goal of this work is to generate photosynthetic bio-processes which use the algae as solar-powered green cell factories for sustainable terpenoid production.
Structural diversity of terpenoids