Journal of Bioprocessing & Biotechniques

Whole-Cell Biocatalysis for 4-Hydroxyisoleucine (4-HIL) production in E. coli

Abstract

Gaurav Prajapati, Meenakshi Pawar and Kinshuk Raj Srivastava*

4-HydroxyIsoLeucine (4-HIL) is a valuable non-proteinogenic amino acid with potent insulinotropic properties, offering significant therapeutic potential for the treatment of type 2 diabetes and metabolic disorders. Currently, the industrial availability of 4-HIL is limited by the low yields obtained from Trigonella foenum-graecum (fenugreek) seeds and the environmental burden associated with chemical synthesis. To address these limitations, this study establishes a sustainable whole-cell biocatalytic platform for the production of 4-HIL using recombinant Escherichia coli containing L-isoleucine dioxygenase (IDOI162T/T182N). Thus, a whole-cell biotransformation system was subsequently developed, wherein the engineered cells catalysed the regio- and stereoselective hydroxylation of exogenously supplied L-isoleucine in the presence of α-ketoglutarate, FeSO? and ascorbic acid. This work demonstrates a robust and scalable "green" synthetic route for 4-HIL production, offering a viable alternative to traditional plant extraction for pharmaceutical applications.