Malic acid production through the whole-cell hydration of fumaric acid with immobilised Rhizopus oryzae

• Published in: Biochemical engineering journal Vol. 137; pp. 152 - 161
• Main Authors: Naude, Andre, Nicol, Willie
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-09-2018
• Subjects: Biocatalysis; Bioconversion; Immobilisation; Malic acid; Rhizopus oryzae; Malic acid; Bioconversion; Biocatalysis; Rhizopus oryzae; Immobilisation
• ISSN: 1369-703X; 1873-295X
• DOI: 10.1016/j.bej.2018.05.022

•Rhizopus oryzae demonstrated excellent malic acid production capabilities.•Biomass preparation was easier compared to existing processes.•No by-products were produced.•Maximum specific malic acid production was 3.78 g g−1 h−1.•Production rate half-life was 40 h.
The production of malic acid from fumaric acid using Rhizopus oryzae as a whole-cell bioconversion process was investigated. Biomass preparation and immobilisation were more straightforward compared with Bravibacterium flavum and Saccharomyces cerevisiae. Anaerobic operation greatly increased the process half-life, which also increased with an increasing sodium concentration in the medium. A model was proposed and validated using repeat-batch and continuous experiments. The results indicated a maximum specific productivity of 3.78 g g−1 h−1 and a process half-life of 40 h, which compares favourably with both B. flavum and S. cerevisiae. No other by-products were formed during the hydration reaction.