Evidence for a cytoplasmic pathway of oxalate biosynthesis in Aspergillus niger

Journal Article · Tue Mar 01 00:00:00 EST 1988 · Appl. Environ. Microbiol.; (United States)

OSTI ID:7026847

Kubicek, C P; Schreferl-Kunar, G; Woehrer, W; Roehr, M

Oxalate accumulation of up to 8 g/liter was induced in Aspergillus niger by shifting the pH from 6 to 8. This required the presence of P/sub i/ and a nitrogen source and was inhibited by the protein synthesis inhibitor cycloheximide. Exogenously added /sup 14/CO/sub 2/ was not incorporated into oxalate, but was incorporated into acetate and malate, thus indicating the biosynthesis of oxalate by hydrolytic cleavage of oxaloacetate. Inhibition of mitochondrial citrate metabolism by fluorocitrate did not significantly decrease the oxalate yield. The putative enzyme that was responsible for this oxaloacetate hydrolase (EC 3.7.1.1), which was induced de novo during the pH shift. Subcellular fractionation of oxalic acid-forming mycelia of A. niger showed that this enzyme is located in the cytoplasm of A. niger. The results are consistent with a cytoplasmic pathway of oxalate formation which does not involve the tricarboxylic acid cycle.

• Research Organization: Institut fuer Biochemische Technologie und Mikrobiologie, Vienna (Austria)
• OSTI ID: 7026847
• Journal Information: Appl. Environ. Microbiol.; (United States), Vol. 54:3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ASPERGILLUS
METABOLISM
OXALATES
BIOSYNTHESIS
BIOLOGICAL PATHWAYS
CARBON 14 COMPOUNDS
CYTOPLASM
ENZYME ACTIVITY
HYDROLASES
PH VALUE
TRACER TECHNIQUES
CARBOXYLIC ACID SALTS
CELL CONSTITUENTS
ENZYMES
FUNGI
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
PLANTS
SYNTHESIS
550501* - Metabolism- Tracer Techniques