01162naa a2200157 a 450000100080000000500110000800800410001910000120006024500780007226000090015052007270015965300250088665300150091170000190092677300590094516466381995-10-10       1948    bl ---       0--  u    #d1 aSHU, P.  aCitric acidbProduction by submerged fermentation with aspergillus niger.  c1948  aAverage yields of 72 grams of anhydrous citric acid per 100 grams of added sucrose were obtained by submerged culture of Aspergillus niger in shake flasks on a synthetic medium at an initial sucose concentration of 140 grams per liter. The fermentation required 9 days. A 70% yield was obtained in 12 days at a sucrose concentration of 260 grams per liter. data on the effect of changes in composition of the medium are presented. the optimal conditions for shake flask fermentations include potassium dihydrogen phosphate above 1 gram per liter, magnesium sulfate heptahydrate above 0.25 gram per liter, iron concentration of 1mg. per liter, 2.5 grams per liter of ammonium nitrate, and an initial pH between 2.2 and 4.2.  aCondicoes ambientais  aNutrientes1 aJOHNSON, M. J.  tIndustrial and Engineering Chemistrygv.40, n.7, 1948.