African Journal of

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12362

Full Length Research Paper

Solid state fermentation studies of citric acid production

Ashish Kumar1* and V. K. Jain2
1Central Research & Development Laboratory, Hindustan Zinc Limited, P.O. Zinc Smelter, Debari, Pin 313024, Dist. Udaipur, Rajasthan, India. 2Department of Biochemical Engineering and Food Technology, H. B. Technological Institute, Kanpur-208002, U.P., India.
Email: [email protected]

  •  Accepted: 27 November 2007
  •  Published: 04 March 2008


Treated sugarcane bagasse supplemented with sucrose medium was found 1.7 fold (citric acid based on sugar consumption) better substrate than untreated bagasse carrier. The performance of packed bed reactor at aeration rate of 0.75 l/min and apparent packing density of 35.0 g/l was superior with citric acid yield of 55.90% (w/w), overall productivity of 0.087 g/100 g DS.h and specific growth rate of 0.055 h-1. However, in flask fermentation citric acid yield of 41.56% (w/w) with overall productivity of 0.064 g/100 gDS.h and specific growth rate of 0.043 h-1 was observed. The system confirmed that citric acid production was Type-II fermentation. Citric acid recovery of 90.39% (w/w) was achieved from fermented broth.


Key words: Aspergillus niger, kinetics, packed bed reactor, sugarcane bagasse.