There is a shortage of off the shelf antiviral compounds that work against a range of viruses. Virus outbreaks, like the recent SARS-CoV-2 pandemic, are common and it is important that this shortage is addressed.

Challenge

This project sought to identify antiviral therapeutics that can be extracted from the cyanobacterium, Arthrospira platensis, a filamentous cyanobacterium, often termed spirulina. Cyanobacteria are used in commercial production of a range of products such as food colourants, and although it is known that antiviral molecules can be extracted from them, it is not known which emerging virus families, likely to cause pandemics, these antivirals are effective against.

ScotBio have a range of commercial products on the market which are produced from spirulina. There is evidence that there may be antiviral compounds within spirulina that ScotBio were interested in investigating.

This project screened promising molecules against SARS-CoV-2-like viruses to define their activity and cytotoxicity to identify compounds for further analysis.

Solution

ScotBio worked with Robert Gordon University to prepare spirulina extracts, before separating both the extracts and the spent culture medium into a number of fractions. Fractions were categorised into different chemical groups, before screening at the University of Edinburgh for activity against a range of viruses.

RGU supervised the fractionation (separation into different, chemically distinct portions) of the spirulina extracts and provided some characterisation of the active fraction.  

University of Edinburgh performed the virology experiments which required cell lines and equipment that the company could not have accessed without academic collaboration.

Seven fractions were produced and sent for testing. None of the fractions showed cytotoxicity (toxicity to cells), but one of the extracts showed antiviral activity against SARS-CoV-2 pseudotypes (covid) and 229E-HCoV (common cold). This fraction was partially characterised and shown to contain repeating sugar units.

Outcome

The project gave ScotBio leverage for more grant funding and incentivised the recovery of polysaccharides from waste streams, as well as identifying compound targets for chemical manipulation and generation of patentable products. ScotBio also benefitted from training and experience in chemical analysis and project management.

RGU adopted new methods for fractionating and purifying polysaccharides and methods for monosaccharide analysis of microalgal hydrolysates. They also benefitted from leverage for more grant funding.

University of Edinburgh benefitted from training opportunities for a new PhD student, proof of concept and resources for the continuation and development of PhD and MRS projects.