GRAM-SCALE SYNTHESIS OF RECOMBINANT CHITOOLIGOSACCHARIDES IN ESCHERICHIA-COLI

Cultivation of Escherichia coli harbouring heterologous genes of oligo saccharide synthesis is presented as a new method for preparing large quantities of high-value oligosaccharides. To test the feasibility of this method, we successfully produced in high yield (up to 2.5 g/L) pe nta-N-acetyl-chitopentaose (1) and its deacetylated derivative tetra-N -acetyl-chitopentaose (2) by cultivating at high density cells of E. c oli expressing nodC or nodBC genes (nodC and nodB encode for chitoolig osaccharide synthase and chitooligosaccharide N-deacetylase, respectiv ely). These two products were easily purified by charcoal adsorption a nd ion-exchange chromatography. One important application of compound 2 could be its utilisation as a precursor for the preparation of synth etic nodulation factors by chemical acylation. (C) 1997 Elsevier Scien ce Ltd.