Optimization of Biocatalyst Specific Activity for Glycolic Acid Production

A chemoenzymatic process has been developed that employs an immobilized microbial nitrilase biocatalyst for the conversion of glycolonitrile to high-purity glycolic acid. The specific activity of this immobilized cell biocatalyst decreased significantly during initial use in either consecutive batch reactions with catalyst recycle, or in a continuous stirred-tank reactor, but the nitrilase activity remaining after this initial decrease was stable under the reactions conditions. The initial stability of this immobilized cell nitrilase catalyst has been improved by treatment of the microbial cells with glutaraldehyde prior to immobilization. Conditions for glutaraldehyde treatment were defined that completely inactivated the culture without significantly affecting nitrilase activity. A method for dehydration, storage and rehydration of the carrageenan-immobilized cells has also been demonstrated that further improves the specific activity of this biocatalyst.

[1]  E. Power.  Aldehydes as biocides , 1997 .

[2]  R. Fallon,et al.  Chemoenzymic Production of Lactams from Aliphatic α,ω-Dinitriles , 1998 .

[3]  J. Koeleman,et al.  Glutaraldehyde: Current Status and Uses , 1994, Infection Control & Hospital Epidemiology.

[4]  S. Gorman,et al.  Antimicrobial activity, uses and mechanism of action of glutaraldehyde. , 1980, The Journal of applied bacteriology.

[5]  W. Woodside,et al.  Studies on the mode of action of glutaraldehyde on Escherichia coli. , 1973, The Journal of applied bacteriology.

[6]  M. Payne,et al.  Purification, cloning, sequencing and over-expression in Escherichia coli of a regioselective aliphatic nitrilase from Acidovorax facilis 72W , 2003, Applied Microbiology and Biotechnology.

[7]  J. F. Gardner,et al.  Biocidal activities of glutaraldehyde and related compounds. , 1967, The Journal of applied bacteriology.

[8]  Isabelle Migneault,et al.  Glutaraldehyde: behavior in aqueous solution, reaction with proteins, and application to enzyme crosslinking. , 2004, BioTechniques.

[9]  Marin Berovic.  Sterilisation in biotechnology. , 2005, Biotechnology annual review.

[10]  Thomas Foo,et al.  Chemoenzymatic Synthesis of Glycolic Acid , 2007 .

[11]  M. Payne,et al.  Optimization of an immobilized-cell biocatalyst for production of 4-cyanopentanoic acid , 2002 .

[12]  R. Fallon,et al.  A Gram-negative bacterium producing a heat-stable nitrilase highly active on aliphatic dinitriles , 1999, Applied Microbiology and Biotechnology.

[13]  A. Middelberg,et al.  The effect of thermal deactivation on the properties and processing characteristics of E. coli. , 1996, Bioseparation.

[14]  Shijun Wu,et al.  Protein engineering of nitrilase for chemoenzymatic production of glycolic acid. , 2008, Biotechnology and bioengineering.

[15]  R. Fallon,et al.  Chemoenzymatic production of 1,5-dimethyl-2-piperidone , 2001 .

[16]  J. B. Jones,et al.  Chemical modification of enzymes for enhanced functionality. , 1999, Current opinion in biotechnology.

[17]  M. R. Russo,et al.  Inactivation of glutaraldehyde by reaction with sodium bisulfite. , 1996, Journal of toxicology and environmental health.

[18]  J. S. Pai,et al.  Permeabilization of Escherichia coli cells for enhanced penicillin acylase activity , 1994 .