Simultaneous hydrolysis and fermentation (SHF) of sweet sorghum juice is a multi-step process and interactions between enzymes inside the yeast and the complex substrate. In addition, SHF also undergoesmechanisms by the product and other components inside the substrate. The process, interactions, and as well as inhibition mechanism of SHF are not fully understood. A modified kinetics model based on those reported by Philippidis [24] and Shadbahr [17] were used in this study to quantify the sucrose hydrolysis and sugars fermentation. However, the original version of kinetics model [24] was also used as for the comparison. The kinetics model assumes that the yeast both consume and hydrolyze the sucrose into glucose and fructose. The rate of sucrose hydrolysis is shown on Eq. 1 below. One mole of glucose or fructose (180 g/mol) will be fermented to two moles of ethanol (46 g/mol) and two moles of carbon dioxide (44 g/mol). The reaction pathway for the biochemical conversion of sucrose is supposed to follow the pathway shown by Figure 2.
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The general idea is that the growth accumulation is the subtraction of bacteria growth and bacteria death. There are two different kinetics models proposed to explain the growth mechanism of the yeast as shown by Eq. 2 and Eq. 3. The Eq. 3 considered that either glucose or fructose had its own saturation constant due to the fondness of most yeast species to the glucose [25] which led to the different rate of glucose and fructose utilization by the
The general idea is that the growth accumulation is the subtraction of bacteria growth and bacteria death. There are two different kinetics models proposed to explain the growth mechanism of the yeast as shown by Eq. 2 and Eq. 3. The Eq. 3 considered that either glucose or fructose had its own saturation constant due to the fondness of most yeast species to the glucose [25] which led to the different rate of glucose and fructose utilization by the