Production of O-acetylated and sulfated chitooligosaccharides by recombinant Escherichia coli strains harboring different combinations of nod genes

High cell density cultivation of recombinant Escherichia coli strains harbo ring the nodBC genes (encoding chitooligosaccharide synthase and chitooligo saccharide N-deacetylase, respectively) from Azorhizobium caulinodans has b een previously described as a practical method for the preparation of gram- scale quantities of penta-N-acetylchitopentaose and tetra-N-acetylchitopent aose (Samain, E., Drouillard, S., Heyraud, A., Driguez, H., Geremia, R.A., 1997. Carbohydr. Res. 30, 235-242). We have now extended this method to the production of sulfated and O-acetylated derivatives of these two compounds by coexpressing nodC or nodBC with nodH and/or nodL that encode chitooligo saccharide sulfotransferase and chitooligosaccharide O-acetyltransferase, r espectively. In addition, these substituted chitooligosaccharides were also obtained as tetramers by using nodC from Rhizobium meliloti instead of nod C from A. caulinodans. These compounds should be useful precursors for the preparation of Nod factor analogues by chemical modification. (C) 1999 Else vier Science B.V. All rights reserved.