Shikimic acid, a base compound for the formulation of swine/avian flu drug: statistical optimization, fed-batch and scale up studies along with its application as an antibacterial agent

Abstract

The sudden outbreak of swine flu has increased the global demand of shikimic acid which is an industrially interesting compound, as it is used as a key starting material for the synthesis of a neuraminidase inhibitor Tamiflu®, for the treatment of antiviral infections such as swine flu. Statistical optimization and evaluation of medium components for the production of shikimic acid by Citrobacter freundii is addressed in the present investigation. Plackett–Burman design was applied for the screening of the most significant variables affecting shikimic acid production, where glucose, asparagine, KH2PO4, CaCO3 and agitation rate were the most significant factors. Response surface methodology was also employed to study the interaction among the most significant variables through which shikimic acid production increased to 12.76 g/L. Further, fed-batch studies resulted in the production of 22.32 g/L of shikimic acid. The scalability of the process was also confirmed by running 14 L bioreactor (7.5 L production medium) where 20.12 g/L of shikimic acid was produced. In addition the antibacterial activity of the shikimic acid produced was analysed against four Gram positive and four Gram negative bacteria and it was found to have a greater inhibition effect against the Gram negative bacteria.