African Journal of Biotechnology Vol. 2 (10), pp. 356-359, October 2003

ISSN 1684-5315  © 2003 Academic Journals

Full Length Research Paper

Citric acid production from whey with sugars and additives by Aspergillus niger

Murad A. El-Holi and Khalaf S. Al-Delaimy٭

Department of Nutrition and Food Technology, Faculty of Agriculture, The university of Jordan, Amman, Jordan.

*Corresponding author; Tel.: 00962-6-5355000/2568, Fax: 00962-6-5355577, E-mail: delaimy@ju.edu.jo.

Accepted 22 September 2003  

Citric acid (CA) production by Aspergillus niger ATCC9642 from whey with  different concentrations of sucrose, glucose, fructose, galactose  riboflavin, tricalcium phosphate and methanol in surface culture process was studied. It was found that whey with 15% (w/v) sucrose with or without 1% methanol was the most favourable medium producing the highest amount (106.5 g/l) of citric acid. Lower CA was produced from whey with other concentrations of sugars and other additives used. Highest biomass of A. niger was produced with the addition of riboflavins. In general, extension of the fermentation (up to 20 days) resulted in an increase in CA and biomass, and decrease in both residual sucrose and pH values.

Key words: Citric acid, Aspergillus niger, whey fermentation, surface culture.