The Influence of Nitrogen Sources on Ethanol Production from Concentrated Sweet Sorghum Juice
Ethanol production from concentrated sweet sorghum juice was carried out under very high gravity (VHG) fermentation conditions using Saccharomyces cerevisiae yeast strain at 30℃. Different nitrogen sources (CO(NH2)2 or (NH4)2SO4), with the concentration of 0.8g nitrogen/L, were added to promote the ethanol yields and prevent the byproducts formation (no additional phosphorus). With an initial sugar concentration of 300 g/L, the maximum ethanol concentration and cell number of the fermentation medium with CO(NH2)2, as nitrogen source (135 g/L and 5.5 ×108/L, respectively) were higher compared to those of the control one (120 g/L and 4.7× 108/L, respectively). However, no positive effects of(NH4)2SO4 were observed compared with the control. The total yield of glycerol and acetic acid obtained with CO(NH2)2 as a nitrogen source was 0.027 g/g sugar, which was clearly lower than those for ammonium-grown culture (0.035 g/g sugar) and the control (0.037 g/g sugar). The lower values of glycerol and acetic acid yields indicate that CO(NH2)2, succeeds in the efficient balancing of the redox potential and reduces the formation of byproducts during VHG fermentation compared with that when, for example, ammonium salt is the only available nitrogen source.
Ethanol Urea Sweet sorghum juice Very high gravity fermentation Glycerol
Jianliang Yu Jing Zhong Xu Zhang Tianwei Tan
Beijing Key Lab of Bioprocess,College of Biology Science and Technology,Beijing University of Chemical Technology,Beijing 100029,China
国际会议
广州
英文
747-750
2008-12-03（万方平台首次上网日期，不代表论文的发表时间）