Batch Fermentation of Recombinant Burkholderia Intracellular Motility A Protein in Escherichia coli for the Diagnosis of Equine Glanders

Abstract

Burkholderia mallei is the causative agent of glanders, and it is a category B biothreat agent. A simple and rapid diagnostic tool is essential for control of glanders. We have previously shown the usefulness of a novel Burkholderia intracellular motility A (BimA) protein in glanders diagnosis. Efficient strategies for the production of this novel recombinant protein are important because of the requirement of high amounts of high-quality protein. We optimized the production and downstream process of recombinant (rBimA) protein from Escherichia coli host. Optimized fermentation culture medium (modified terrific broth) was evaluated for production of recombinant (rBimA) protein in shake flasks. The recombinant protein was further produced by batch fermentation using 5-L bioreactor. Cells were grown in optimized modified terrific broth medium; culture was induced with 0.5-mM isopropyl-β-D-1-thiogalactopyranoside and further grown for 8 hours to reach 16.0 g/L dry cell weight. The recombinant (rBimA) protein was purified from inclusion bodies under denaturing conditions using metal affinity chromatography, which yielded 178.50 mg/L of protein. The purified protein was found to be reactive with B. mallei–infected equine serum samples.