Electrochemical oxidation of oxalic acid has been investigated at bare, highly boron-doped diamond electrodes. Cyclic voltammetry and flow injection analysis with amperometric detection were used to study the electrochemical reaction. Hydrogen-terminated diamonds exhibited well-defined peaks of oxalic acid oxidation in a wide pH range. A good linear response was observed for a concentration ran...

Efficient ligninolytic systems of wood-degrading fungi include not only oxidizing enzymes, but also low-molecular-weight effectors. The ability of Bjerkandera fumosa to secrete oxalic acid and versatile peroxidase (VP) in nitrogen-rich and nitrogen-limited media was studied. Higher activity of VP was determined in the nitrogen-limited media but greater concentration of oxalic acid was observed ...

1. As varying amounts of calcium oxalate may be held in solution in the urine, conclusions based upon the presence or number of calcium oxalate crystals found therein are of no real value as an indication of the quantity of oxalic acid present. 2. Unless the utmost care is exercised, the results obtained by quantitative estimation of oxalic acid are subject to large percentages of error. This i...

Oxalic acid produced by Aspergillus niger under submerged conditions in this work. Optimization done with different sources of carbon, nitrogen, minerals and at different pH then biomass production done of Aspergillus niger under submerged conditions for 7 days at room temperature. Further supernatant taken for titration and mycelium for oxaloacetate acetylhydrolase determination by SDS-PAGE. K...

SYNOPSIS Observations are reported on five cases of suicide or attempted suicide by poisoning with oxalic acid or ethylene glycol. Elevated oxalic acid levels were observed in the plasma, stomach contents, and a number of tissues. Raised oxalic acid levels in plasma were associated with reduced total and ultrafilterable calcium levels. It is suggested that the reduction in plasma total calcium ...

Rumen microbial degradation is an important route for detoxification of secondary plant compounds encountered in the diets of free-grazing ruminants. Exposure to diets containing particular secondary plant compounds can lead to increased rates of secondary compound degradation in the rumen. An experiment was conducted to determine whether rumen adaptation to oxalic acid would influence the diet...

Large quantities of oxalic acid accumulate in the cell sap of various plants and as a major product of carbohydrate metabolism by many molds. A recent investigation in our laboratory revealed that oxalic acid was produced from oxalacetic acid by an enzyme system which was isolated from the mycelia of Aspergillus niger (1). It was also demonstrated that oxalic acid was converted to formic acid a...

Aspergillus niger has shown production of metal chelating compounds mainly oxalic acid and citric acid. Production of oxalic acid by Aspergillus niger was found maximum in presence of Pb, followed by Cu+Pb and Cu. With increase in concentration of Pb to 50, 100 and 250 mg/L, the production of oxalic acid was increased. Whereas increase in concentration of Cu+Pb and Cu, resulted in decreased pro...

The heterogeneous ice nucleation potential of airborne oxalic acid dihydrate and sodium oxalate particles in the deposition and condensation mode has been investigated by controlled expansion cooling cycles in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at temperatures between 244 and 228 K. Previous laboratory studies have highlighted the particular role of oxal...

It is known that oxalic acid is a product of ascorbic acid metabolism in the guinea pig (1) and rat (2), and is formed in man from unidentified precursors (3). Oxalates are also of interest because of their occasional toxicity and unexplained deposition. Ascorbic, dehydroascorbic, and 2,3diketogulonic acids are known to give rise to oxalic and threonic acids in approximately quantitative yields...