This is Pandeeswari Jeeva’s application video for the Engage your Audience! 2017 contest, which she participated in during FEMS 2017.

Genetic engineering of Saccharomyces cerevisiae for hyaluronic acid production

Hyaluronic acid (HA) is vital for normal growth and development of vertebrate which makes it as a commercially valuable polysaccharide in pharmaceutical and cosmetics industries. HA is synthesized by polymerization of two nucleotide sugars UDP-glucuronic acid and UDP-N-acetylglucosamine by the enzyme HA synthase (hasA). Two major genes required for the formation of HA monomers are hasB (UDP-glucose dehydrogenase) and hasD (glucosamine-phosphate acetyl transferase) respectively. Native Streptococcal species are being used for industrial scale production of HA, however, the presence of endotoxins and pathogenic factors renders it unsuitable for medical purposes. Hence, this demands for metabolic engineering of Generally Recognized As Safe (GRAS) microbes to produce HA. We have chosen Saccharomyces cerevisiae as a host for HA production due to its advantages such as lack of pathogenecity and hyaluronidase. In addition, it does not produce HA or any other polysaccharide that contains glucuronic acid due to absence of hasA and hasB. Thus, it makes S. cerevisiae a superior model system to elucidate HA biosynthesis. Jeong et.al., (2014) has demonstrated the expression of has genes from Xenopus laevis, though with low yield, in Pichia pastoris for HA production. In the current work, we have expressed X. laevis has genes in S. cerevisiae for producing medical-grade HA.