ABSTRACT
Hyaluronic acid (HA) is a linear and unbranched high molecular weight polysaccharide. The rooster comb-based extraction process is facing a growing concern over the use of animal-derived components in biomedical and pharmaceutical applications. Hence, microbial production of HA has emerged as a new alternative. Molecular weight is an important quality parameter for a commercial HA product, as it determines the HA's rheological properties, affects physiological response, and defines suitable applications. The continuous rise in the cost of raw materials weakens the commercial competiveness of microbial HA production, and thus it is necessary to find a cheaper substrate replacement to reduce production cost. It is necessary to obtain specially designated molecular weight or uniform size-defined HA to extend the applications of HA and make better HA containing biomedical products. Despite an HA polymerization model having been put forward, and some key intracellular metabolites influencing molecular weight having been clarified, work needs to be performed to understand mechanism of molecular weight control.
