Question

How do you convert SCB into xylitol ? ​

Answer 1

Answer:

The xylitol production has become an important process to investigate given the diverse product applications, especially in the food industry. The biotechnological xylitol production has been assessed mainly through an experimental approach via batch and fed-batch operation.

Explanation:

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Answer 2

Answer:

The xylitol production has become an important process to investigate given the diverse product applications, especially in the food industry. The biotechnological xylitol production has been assessed mainly through an experimental approach via batch and fed-batch operation. This study presents an analysis for optimal operation of the fed batch process following a systematic methodology. The model based approach includes the collection, validation and calibration of the mathematical model, followed by the proposal of some operation scenarios. The implementation of such methodology allowed to increase 20% the yield of xylitol compared with the obtained previously in some experiments. Moreover, an analysis for the diauxic phenomenon was also performed, allowing to determine an optimal feeding ratio between substrates.

R2 0.999 0.994 0.994

The SRC provides the linear model determination coefficient (R2) shown in Table 1. The R2 values were very close to 1 for all the analysed variables, which means that the model outputs could be linearized to a high degree and the βi to be used as a reliable index of the sensitivity measure. Figure 2 illustrates the uncertainty decomposition for final biomass, xylose and xylitol concentration. The biomass production is mainly affected by maximum specific growth rate on xylitol (μmax,xit) and the saturation constant based on xylitol (Ks,xit). Regarding to xylose consumption and xylitol production, there are two main parameters which have high effect in their outputs, the maximum specific uptake rate of xylose (qmax,xyl) and the saturation constant based on xylose (Ks,xyl).

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Figure 2. Uncertainty decomposition by the SRC method for biomass production, xylose consumption and xylitol production.

The four identified parameters with higher influence in the model outputs were the only recalibrated at step 2 at prior work (Prado-Rubio et al., 2015) and the sensitivity analysis confirmed which output variable is indeed influencing the model. As previously mentioned, the identified parameters show the potential effect in the production of xylitol due to disturbances, for example, whether there is lower specific uptake rate of xylose than estimated owe to the presence of unexpected species such as inhibitors, toxics, microorganisms, etc., that would affect the desired yield. Therefore, relying on the previous results, the four identified parameters are used to foresee some potential disturbances during the fermentation that must be rejected in controlled scenarios.