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Table 3 Effects of nitrogen source supplementation on ethanol production and sugar consumption

From: Conditions promoting effective very high gravity sugarcane juice fermentation

  PE-2 CAT-1
Ethanol (ml L−1) Consumed sugar (g L−1) Ethanol (ml L−1) Consumed sugar (g L−1)
°Brix 25 30 35 25 30 35 25 30 35 25 30 35
Ammonium phosphate (DAP)
 Fermentation cycle 1 106.9 aB 95.5 bE 84.9 cG nd nd nd 120.8 bD 128.7 aG 130.9 aD nd nd nd
2 139.2 bA 146.7 aBC 140.6 bAB 255.1 cA 240.0 bDE 278.0 aE 148.2 aAB 153.2 aDE 151.3 aA 244.1 bB 309.0 bF 259.9 aA
3 139.4 aA 138.0 aD 138.4 aBC nd nd nd 135.3 bC 129.6 bG 150.3 aA nd nd nd
4 142.9 aA 144.4 aC 144.6 aAB 255.0 cA 243.9 bCD 291.6 aF 146.8 aAB 145.2 aEF 146.0 aAB 242.8 bAB 307.6 bEF 258.8 aA
5 138.9 cA 157.8 aA 146.8 bA nd nd nd 142.6 bABC 149.3 aEF 149.6 aA nd nd nd
6 141.6 bA 158.4 aA 142.0 bAB 255.1 cA 269.9 bF 278.8 aE 140.7 aBC 143.9 aF 145.1 aABC 237.7 bAB 299.6 bDEF 254.5 aA
 AVERAGE (ml L−1) 134.8 140.1 132.9 139.1 141.7 145.5
 SUM (ml) 8089 8408 7973 8344 8499 8732
Urea
 Fermentation cycle 1 112.7 aB 97.2 bE 69.6 cH nd nd nd 135.6 aC 126.8 bG 136.6 aCD nd nd nd
2 142.9 aA 146.3 aBC 116.4 bF 255.1 cA 65.2 bC 184.8 aA 151.1 bA 174.4 aA 149.1 bA 244.1 cB 294.6 bDE 250.1 aA
3 142.2 aA 142.9 aCD 125.2 bF nd nd nd 149.2 aAB 79.3 bH 148.1 aA nd nd nd
4 141.0 bA 152.2 aAB 129.6 cDE 255.0 cA 65.6 bC 207.0 aC 148.8 bAB 160.9 aCD 148.8 bA 243.8 cAB 276.8 bC 256.6 aA
5 141.2 bA 153.2 aA 132.3 cCD nd nd nd 149.6 bA 165.3 aBC 147.2 bAB nd nd nd
6 139.4 bA 158.2 aA 127.7 cDE 255.2 cA 48.7 bE 211.7 aC 143.5 bABC 171.0 aAB 138.9 bBCD 244.1 cB 289.2 bCD 258.7 aA
 AVERAGE (ml L−1) 137.6 141.7 116.8 146.3 146.3 144.8
 SUM (ml) 8194 8500 7008 8778 8777 8687
  1. Results are shown for ammonium phosphate and urea supplemented very high gravity sugar cane juice fermentations with S. cerevisiae strains PE-2 and CAT-1 at 25, 30 and 35 °Brix. The results given are for the end of each 24-h fermentative cycle and are the average of three independent assays. Significantly different values are identified by different letters; different lower case letters indicate statistical differences within each fermentation batch, whereas different capital letters indicate statistical differences between different fermentation batches. Italics: maximum ethanol concentration produced by each strain. The aggregated cumulative value of ethanol produced at the end of the full six cycles is also shown (ml) as well as the corresponding relative production in   ml L−1