Glycolic Acid → Glyoxylic Acid

Participants

Reaction Conditions

Reaction Steps

A 300-mL EZE-Seal stirred autoclave reactor (Autoclave Engineers) was charged with 100 mL of a solution containing glycolic acid (0.500M), aminomethylphosphonic acid (0.375M), isobutyric acid (0.100M, HPLC internal standard), and flavin mononucleotide (0.01 mM) at pH 8.3 (adjusted with 50% NaOH), and the solution cooled to 5° C. Frozen (-80° C.) Aspergillus nidulans FT17SYCSL/OL (26 g, 124 IU glycolate oxidase and 57,800 IU catalase) were allowed to thaw at 5° C., then washed with 2×100 mL of KH2PO4 (50 mM, pH 7.0)/FMN (0.01 mM) buffer at 5° C. and the washed cells added to the reactor with 1.4×106 units of Aspergillus niger soluble catalase (Sigma). The pH of the resulting mixture was re-adjusted to 8.3 with 50% NaOH, then stirred at 400 rpm and 5° C. under 120 psig of oxygen while bubbling oxygen through the mixture at 50 mL/min. After 11.5 hours, the yields of glyoxylic acid, oxalic acid, and formic acid were 94%, 3.5%, and 2.7%, respectively, with 1.3% recovery of glycolic acid. The final activities of glycolate oxidase and Aspergillus niger catalase were 7% and 77% of their initial values.

Provenance & Evidence