Anaerobic Formation of Fumaric Acid by the Mold Rhizopus nigricans

AEROBIC FORMATION OF FUMARIC ACID IN TiE MOLD RHIZOPUS NIGRICANS: SYNTHESIS B

Mechanism of fumaric acid accumulation in Rhizopus nigricans.

It is doubtful that the glyoxylate bypass plays a significant role in the accumulation of fumaric acid by fungi, as has been postulated. In high glucose media, which favor fumarate production, isocitrate lyase (threo-D(s) isocitrate glyoxylate lyase), which is the key enzyme of the glyoxylate bypass, is strongly repressed. The specific activity of this enzyme remains low as long as glucose is p...

Control of malate synthase formation in Rhizopus nigricans.

The control of malate synthase formation in a fumaric acid-producing strain of Rhizopus nigricans has been found to be similar in most respects to that of isocitrate lyase, the companion enzyme of the glyoxylate bypass. A basal level is formed in a casein hydrolysate medium, which is repressed by glucose. Utilization of glucose during growth results in relief of glucose repression. Any factor w...

Fumaric acid, anti-thrombin substance from Rhizopus javanicus.

An anti-thrombin substance (M2) was isolated from a culture broth of Rhizopus javanicus. Accumulation of M2 reached a maximum peak after 14 to 15 days of incubation and then decreased. The yield of M2 was 500 mg from 1 L of culture broth. M2 inhibited thrombin activity, and its 50% inhibition concentration in a reaction mixture containing 50 microL of 12.5 NIH unit/mL thrombin and 200 microL of...

Protoplast fusion of Rhizopus oryzae and Rhizopus microsporus for enhanced fumaric acid pr

Rhizopus oryzae and Rhizopus microsporus strains were screened for their ability to produce fumaric acid on glycerol as the sole carbon source in the medium. After seven days of stationary culture, fumaric acid was assayed by HPLC analysis, and maximum concentrations of 0.3% (w/v) and 0.33% (w/v) were recorded. Protoplast fusion was used to improve fumaric acid production. A selective medium fo...