An efficient biocatalyst for the production of sialic acids- sugars for health

The aim of the project has been to bring forward an efficient biocatalyst for the production of sialic acids. Today, the largest market is for use in the production of anti-viral drugs, but the largest future demand will most likely be as a nutritional additive, in particular to infant milk formulas, and for cosmeceutical and pharmaceutical applications. We have optimized enzymes for production of high-value sialic acid starting from N-acetylglucosamine, the building block of chitin. Chitin is an abundant biomass found in for example crustacean shells. One of the enzymes that has been optimized is a sialic acid aldolase. This enzyme has unique properties, also facilitating the use of this enzyme alone for production of sialic acid from the cheaper substrate N-acetylglucosamine. Alternatively, the aldolases are used in combination with N-acetylglucosamin epimerases for production of sialic acid from N-acetylglucosamine. These processes have been compared in this project regarding yield and production costs. The results show that the process at alkaline pH and use of the aldolase alone is cheapest for lab scale production of sialic acid. The enzyme was shown to be more efficient in production of sialic acid than the variant from Escherichia coli, in terms of producing more sialic acid in shorter time. We have also been investigating the potential for using the enzymes in production of sialic acid derivatives with potential application as second-generation anti-infuenza drugs. We have among others produced and determined the structure of a new sialic acid aldolase. This enzyme has another substrate specificity than known sialic acid aldolases and is producing a variant of sialic acid. The commercialization work of the project has resulted in dialogue with different companies by the end of the project period.

Virkninger av prosjektet er økt samarbeid med andre forskningsinstitusjoner rundt temaet biomassekonvertering, økt interaksjon med industri, og en pågående dialog med ulike aktører knyttet til kommersialisering av prosess/produkt. Nye samarbeidsprosjekt har oppstått som følge av dette prosjektet. Prosjektet har gitt økt innsikt i valorisering av kitin-rik biomasse og N-acetylglukosamin. Prosjektet har bidratt til økt fokus rundt prosessene og produktene, gjennom aktivt å formidle resultater både til industrielle interessenter og det generelle publikum. Gjennom populærvitenskapelige artikler har vi hatt som mål å øke fokus i samfunnet rundt, om viktigheten av og potensialet i å utnytte restråstoff bedre og muligheten til å skape nye produkter ut fra dette.

The project will bring forward an efficient biocatalyst for the production of sialic acids. Today, the largest market is for use in the production of anti-viral drugs, but the largest future demand will most likely be as a nutritional additive, in particular to infant milk formulas, and for cosmeceutical and pharmaceutical applications. The enzymes that are investigated are N-acetylneuraminate lyases (NALs) identified from prospecting of the large in-house collection of marine Arctic bacteria. We are optimizing these enzymes for production of high-value sialic acid starting from sources containing N-acetylglucosamine (GlcNAc), the building block of chitin. Chitin is an abundant biomass found in for example crustacean shells. For one of the NALs, we have filed a patent for a specific application. This cold adapted NAL has unique pH stability and activity compared to the commercially available mesophilic versions. One unique and attractive property is the high stability at high pH that facilitates the use of this enzyme alone for production of sialic acid from the cheaper substrate GlcNAc. This step by itself can reduce the production cost of sialic acid, which comes on top of the benefits of using a much more catalytically efficient enzyme. Alternatively, the NALs can be used in combination with N-acetylglucosamine 2-epimerases (AGEs) for production of sialic acid from GlcNAc. These processes are compared in this project regarding yield and production costs. The results show that the process at alkaline pH and use of the aldolase alone is cheapest in lab scale production of sialic acid. We are also investigating the potential for using the enzymes in production of sialic acid derivatives with potential application as second-generation anti-infuenza drugs. We have among others produced and determined the structure of a new type of NAL which has another substrate specificity than other known NALs. This enzyme is therefore producing a variant of sialic acid. Substrate specificity studies are ongoing to determine what variant this is. Work with identification of potential industry partners is ongoing.