(485y) Metabolic Engineering of Rhizopus Oryzae for Enhanced Production of Fumaric Acid From Sugars

Fumaric acid is a dicarboxylic acid used extensively in resins, food acidulants, and other applications including oil field fluids, esters etc. Some strains of Rhizopus oryzae, which is a filamentous fungus, can produce fumaric acid from sugars under aerobic conditions but the fumarate yield is relatively low due to the co-production of ethanol and other fermentation byproducts. In this work, metabolic engineering technique is applied to optimize the fermentation for enhanced fumaric acid production. Fumaric acid production can be increased by overexpressing fumarase, malate dehydrogenase and pyruvate carboxylase, which are contributive to the fumaric acid formation in cytosolic pathway. These genes were obtained from Rhizopus oryzae genome by using PCR, and then cloned into the fungal cells by biolistic transformation. The effects of transformation on the mutants and fumaric acid fermentation kinetics were studied and will be reported in this paper. The fumaric acid production will be illustrated by exploring the metabolic pathway through the genetic mode.