KSP: Industrial-scale production of diatoxanthin – a high-value product from microalgae with anti-cancer and anti-inflammation properties

In DIATOX, we aim to genetically engineer microalgae to enable industrial production of the rare pigment diatoxanthin. Research indicates that diatoxanthin possesses antioxidant, anti-inflammatory and anti-cancer properties. Diatoxanthin is only found in a few groups of microalgae. Diatoxanthin is produced by the algae as protection against high intensity light and can be viewed as a “sunscreen” pigment. Research on this rare pigment is limited, but recent data implies that diatoxanthin exhibits higher bioactivity than commercially available pigments. Commercial production of diatoxanthin from “natural” microalgae is not feasible since the pigment is rapidly removed from the cells when they are no longer exposed to high intensity light, which will be the case during large-scale harvesting of algal biomass. In addition, producing commercially interesting levels of diatoxanthin in “natural” microalgae will depend on subjecting the algae culture to high intensity light for a prolonged period of time. This can be technically challenging at high cell densities and costly in countries where algae production is dependent on artificial light. In this project, we will create algae mutants that overproduce diatoxanthin without depending on exposure to high intensity light, and where the accumulated diatoxanthin remains stable even after removal of the algae cells from the light source. We will identify optimal cultivation conditions, and harvesting and processing methods that ensure high yield and intact bioactivity of the pigment. Bioactive properties that may have a positive impact on human health will be investigated, and the potential for industrial production will be explored by companies experienced in large-scale microalgae production. Producing a high-value product like diatoxanthin can cause microalgae cultivation to become economically viable, and open up the possibility of using the rest of the algal biomass for feed or production of biofuel.

Microalgae are a sustainable resource that have the potential to meet the world’s energy, feed and material needs. However, the microalgae industry is still in its infancy, and several challenges need to be overcome to lower the production costs of microalgae ingredients. Production of high-value compounds like carotenoids has the potential to secure economic viability of the microalgae industry and pave the way for use of the rest of biomass for e.g. feed and biofuel. Carotenoids are beneficial for human health through their antioxidant effects and might offer protection against a variety of diseases. Recently, the photoprotective carotenoid diatoxanthin has been shown to have pronounced bioactivity, outperforming commercially available carotenoids as a potential disease preventing agent. However, to enable industrial production of the pigment it is necessary to overcome the dependence of prolonged exposure to high light intensities to reach commercially interesting pigment levels and to avoid loss of accumulated diatoxanthin during harvesting of the biomass. In this project we aim to establish a diatoxanthin production line suitable for large-scale commercial production of the pigment. Microalgae mutant lines that overproduce diatoxanthin without the need for high intensity light and where the accumulated product is stable after removal of the algae cells from the light source will be created. Growth conditions will be optimized, and methods will be established for harvesting and processing of the diatoxanthin-containing biomass to maximize yield and secure intact bioactivity of the pigment. To confirm the bioactivity of diatoxanthin and expand upon its published effects relevant to human health, antioxidative, photoprotective and chemotherapeutic properties will be evaluated. The potential for commercial production of diatoxanthin using the gene edited algae strains will be explored by companies experienced in industrial-scale cultivation of microalgae.