acta satech Journal of the Life & Physical Sciences Babcock

Submerged fermentation of Jatropha curcas seedcake to produce oxalic acid by Aspergillus niger and Aspergillus terreus
*Omojasola, P.F. and Okwechime, P.O.
Department of Microbiology, Faculty of Life Sciences, University of Ilorin, Nigeria
April 2018

Agro-industrial wastes mainly from the agricultural and food industries account for several thousand tonnes of waste yearly. These wastes can be further processed to other value-added products via the activities of microorganisms The potential use of Jatropha seedcake as a carbon source for the production of oxalic acid (OA) was investigated using Aspergillus niger (ATCC 16404) and Aspergillus terreus (ATCC 20542). The JSC was used as substrate in submerged fermentation carried out in separate flasks using Mineral Salts Medium for 10 days. Carboxymethyl cellulose was used as a control. Fermentation conditions were: pH 4.68; substrate concentration 10g; inocula size 2 % and temperature 282o C. The fermentation conditions were later varied to optimize OA production. Results showed OA yield of 200 g L-1 and 135 g L-1 by A. niger and A. terreus respectively on Day 8 of fermentation. Results from the optimized fermentations for A. niger that gave highest OA yields were pH 6; substrate concentration of 4g and inocula size of 5 mL. For A. terreus, they were pH 4, substrate concentration 6g and inocula size 4mL. These results support the potential use of Jatropha seed cake for fermentative production of oxalic acid.
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