Scottish biotechnology company ScotBio with funding from IBioIC, and in partnership with group company Allgo Biosciences, has developed an environmentally-friendly way of boosting the production and stability of the natural blue pigment phycocyanin, opening the door to access new global markets.

Introduction

Phycocyanin is a blue pigment extracted from the blue-green algae Spirulina. Although used in many applications, it is vulnerable to heat and acidity, which limits its use in the new fast-growing markets of fashion & textiles and printing, and the traditional markets of food & beverage.

There is increasing social and environmental pressure on the producers of consumer goods to replace artificial ingredients in their products and supply chains. Phycocyanin has traditionally been used in the food and beverage industry, where the natural blue colourant is in high demand as an alternative to the artificial colorants currently used. Due to its brilliant blue colour, there is a growing demand for phycocyanin in new markets such as the textiles and printing industries, and its anti-oxidant and potential anti-aging properties are highly desired by the nutraceutical and cosmetic industries. Nevertheless, phycocyanin from Spirulina tends to be less stable than artificial colourants and more vulnerable to pH, temperature, UV/light, oxygen, and solvents. This poses a barrier for many companies who cannot readily adjust their manufacturing processes.

Challenge

Allgo Biosciences and researchers at the University of Edinburgh had already developed strains of blue-green algae that produce phycocyanin that is more tolerant to extreme conditions, but needed to establish whether it could be produced at commercial scale and remain stable.

Some species of blue-green algae are adapted to live in extreme conditions such as thermal hot springs, and produce more thermotolerant phycocyanin compared with species found in more moderate climates. However, these strains prefer high temperatures to grow, tend to grow slowly, and their yields of phycocyanin are typically low.

Allgo Biosciences (a recently formed group company of long-standing industry partner Tantillus Synergy Limited and sister company to ScotBio) and researchers at the University of Edinburgh discovered that a close relative of Spirulina can be engineered to produce a heat-stable form of phycocyanin at room temperatures, thus enabling industry to scale up its production. They engineered the blue-green algae Synechocystis, a relative of Spirulina, to produce a more heat stable form of the blue pigment from Thermosynechococcus elongatus, which thrives at high temperatures. The power-pairing combines Synechocystis’s ability to produce high yields of phycocyanin at lower temperatures with its thermophile cousin’s ability to make a heat-tolerant form of the pigment.

However, it remained unclear how stable or scalable the cultivation of the engineered Synechocystis  strains would be, how much actual pigment could be generated, or whether these could be processed using conventional methods.

Solution

IBioIC funded a joint project between ScotBio, who partnered with Allgo Biosciences, and the University of Edinburgh to investigate scaling up their cyanobacterial cultivation using IBioIC’s FlexBio facility.

The approach taken was designed to match how conventional phycocyanin extracts are obtained from Spirulina. The heat and acid stability of the engineered-phycocyanin extracts generated were then evaluated and compared with conventional extracts.

The team were able to cultivate the engineered Synechocystis in volumes of 10s of litres and the strains were shown to remain stable under various light and nutrient availability conditions. A viable process was demonstrated, and gram quantities of the final blue powder were produced. The stability of the pigment at both low pH and high temperatures was shown to be superior to conventional pigments.

Outcome

The team successfully engineered a strain of blue-green algae that produced a heterologous ‘nature‑identical’ blue pigment. On testing, the pigment was proved to have better heat and acid stability and could be produced at scale.

This successful project has the potential to overcome some of the key barriers faced by global producers in transitioning to more sustainable and desirable natural colourants for numerous applications. The increase in thermal and acid tolerance of the phycocyanin from the engineered strain has opened opportunities above and beyond the traditional markets for phycocyanin of food & beverage. Markets such as textiles, printing, plastics, nutraceuticals, and cosmetics, where safety and performance are key and where there are no or limited restrictions to using products derived from GMOs . In addition, these molecular biology techniques can be applied to produce other nature‑identical products, which will increase the momentum towards sustainable production and healthy choices for consumers, enhance the reputation of Scotland as a world-leading innovator and open new market opportunities for the commercial partner.

Allgo Biosciences has been established as the group company with a portfolio for the application of molecular and synthetic biology. As phycocyanin is both a colour and protein, this project lays the foundation for future work, using molecular and synthetic biology to enhance the therapeutic protein and nutraceutical space thus future-proofing the group while ScotBio can focus on their core business of natural products.

Impact on partners

The project has answered key proof of concept questions and provided the necessary information and materials to evaluate the route to commercialization. These include further characterisation of the materials via national food and beverage industry bodies, exploring potential interest in new markets and exploring the regulatory barriers across priority territories. The addressable markets are substantial; for example, the global nutraceuticals market was estimated to be worth $382 bn in 2019 with an estimated compound annual growth rate of 8.3%.  

The project also resulted in a paper in Science Direct: Pilot scale production, extraction and purification of a thermostable phycocyanin from Synechocystis sp. PCC 6803: https://www.sciencedirect.com/science/article/pii/S0960852421018010 and provided industrial experience and professional development opportunities to postgraduate students, has progressed the technology readiness level of an active IBioIC collaborative PhD project.

References

Puzorjov, A., Dunn, K. E., & McCormick, A. J. (2021). Production of thermostable phycocyanin in a mesophilic cyanobacterium. Metabolic Engineering Communications, 13, e00175. https://doi.org/10.1016/J.MEC.2021.E00175

Puzorjov, A., Mert Unal, S., Wear, M. A., & McCormick, A. J. (2022). Pilot scale production, extraction and purification of a thermostable phycocyanin from Synechocystis sp. PCC 6803. Bioresource Technology, 345, 126459. https://doi.org/10.1016/j.biortech.2021.126459