Biosynthesis of Chitooligosaccharides by Recombinant Escherichia coli

Abstract:

Acetyl-N-glucosaminyltransferase gene (nodC) was successfully cloned to Escherichia colifrom Mesorhizobium loti. The recombinant E.coli harboring nodC gene was able to synthesize chitooligosaccharides (COs) in MMYNG medium. In optimized condition, a yield of 526 mg/L was obtained after 26 h cultivation in 10 L bioreactor. COs concentration reached up to 4.5% of the cell dry weight. The COs products were purified by charcoal adsorption and Bio-gel P4 chromatography, penta-N-acetylchitopentaose （m/z, 1034［M+H］⁺）and tetra-N-acetylchitopentaose （m/z, 831［M+H］⁺） were identified as the dominating COs product using the method of liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS).