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Alkaline biocatalysis for the direct synthesis of N ‐acetyl‐ D ‐neuraminic acid (Neu5Ac) from N ‐acetyl‐ D ‐glucosamine (GlcNAc)
Author(s) -
Blayer Simone,
Woodley John M.,
Dawson Michael J.,
Lilly Malcolm D.
Publication year - 1999
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(1999)66:2<131::aid-bit6>3.0.co;2-x
Subject(s) - neuraminic acid , epimer , chemistry , aldolase a , biotransformation , biocatalysis , enzyme , stereochemistry , organic chemistry , biochemistry , catalysis , reaction mechanism , sialic acid
Integration between the alkaline epimerization of N ‐acetyl‐ D ‐glucosamine (GlcNAc) to N ‐Acetyl‐ D ‐mannosamine (ManNAc) and the N ‐acetyl‐ D ‐neuraminic acid (Neu5Ac) aldolase‐catalyzed biotransformation has been assessed experimentally. GlcNAc epimerization took place above pH 9.0, and the initial rate of ManNAc formation increased exponentially to 10.37 mmol/L per hour at pH 12. However, above this pH, severe degradation of pyruvate occurred. A value of 31.3% molar conversion on Pyr was achieved in an integrated biotransformation. The “pseudo”‐steady state at the end of the reaction was comparable to the equilibrium achieved with a combination of an epimerase and aldolase enzymes. The integrated reaction proved feasible, but at the expense of pyruvate and Neu5Ac aldolase degradation. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 66: 131–136, 1999.