Utilization of Orange Waste for the Production of Citric Acid via Fermentation

  • P. R. Dahal Central Department of Microbiology, Tribhuvan University, Kirtipur; Kathmandu
  • R. P. Adhikari Royal Nepal Academy of Science and Technology, CPO 3323, Kathmandu
  • M. P. Baral


Raw liquid obtained from juice of orange solid waste was used as a substrate for the production of citric acid by using Aspergillus niger, isolated from the orange waste as starter. The optimum yield was obtained at 30/C on a rotary shaker at 150 rpm. The optimum conditions were incubated upto 96 hr., pH 2.0 - 3.0. The yields of citric acid varied from 2.6 - 5.2 g/1 of the liquid, depending on the sugar content and other physical factors.