Citric Acid Production by Aspergillus niger NRRL 599 Using Whey-based Medium Fortified with Sugar

摘要

Citric acid (CA) production by Aspergillus niger NRRL 599 from cheese whey alone and in combination with different concentrations of sucrose, glucose, fructose, riboflavin, methanol and ammonium sulphate in surface culture process was studied.rnIt was found that whey with 15% (w/v) sucrose produced the highest amount (61.0 g/l) of CA after 10 days. Lower CA values were produced from whey alone or in combination with other concentrations of sugars. Highest biomass of A. niger was produced with the addition of riboflavin. Methanol and ammonium sulphate did not increase CA production when added to whey and 15% sucrose medium.rnThe cumulative effect of fermentation medium, pH (6), riboflavin (10 mg/l) and combination of two sugars (7.5% sucrose + 7.5% fructose) enhanced the production of CA by A. niger NRRL 599 by about 44% after 12 days.