Glycolic Acid → Glyoxylic Acid

Participants

Reaction Conditions

Reaction Steps

A 300-mL EZE-Seal stirred autoclave reactor equipped with Dispersimax Impeller (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. To the reactor was then added 10 g of Pichia pastoris transformant, NRRL Y-21001, (391 IU glycolate oxidase and 457,000 IU catalase) which had been permeabilized by treatment with 0.1% "TRITON" X-100/1 freeze-thaw, and 1.4×106 units of Aspergillus niger soluble catalase (Sigma). The pH of the resulting mixture re-adjusted to 8.3 with 50% NaOH. This mixture was stirred at 1000 rpm, which bubbled oxygen through the mixture via the action of the turbine impeller, and at 5° C. under 120 psig of oxygen. The reaction was monitored by taking a 0.40 mL aliquot of the reaction mixture at regular intervals, filtering the aliquot using a Millipore "ULTRAFREE"-MC 10,000 NMWL Filter Unit, and analyzing the filtrate by HPLC. After 1.0 hour, the yields of glyoxylic acid, oxalic acid, and formic acid were 89.8%, 6.0%, and 2.9%, respectively, with 1.7% recovery of glycolic acid. The final activities of permeabilized-cell glycolate oxidase and catalase were 117% and 78% of their initial values.

Provenance & Evidence