A. M. Mimi Sakinah

Processes for the Production of Xylitol—A Review

Xylitol is a sugar alcohol that is used as a sweetener for diabetics and also for other purposes (e.g., in chewing gum). Industrially, xylitol is manufactured through a chemical process that has some disadvantages, including a high energy requirement, extensive purification steps, and a high cost of product. The microbial production of xylitol has been examined as an alternative to the chemical process, which on an industrial scale is time-consuming mainly due to sterilization and inoculum development. The enzymatic production of xylitol from lignocellulosics is an attractive and promising alternative to the chemical process, potentially eliminating the major disadvantages of conventional processes. This article reviews the literature on xylitol production processes and identifies ways to further improve xylitol synthesis to compete with the current chemical process.

Application of fractional factorial design (FFD) for screening of significant factor in influencing succinic acid production from biodiesel based glycerol: Using Escherichia coli

The production of succinic acid from biodiesel based glycerol was carried out using Escherichia coli K-12 MG1655 strain. The contribution of every parameter was evaluated and optimized using statistical modeling. A 26–1 fractional factorial design (FFD) was applied to screen the effect of substrate concentration, tryptone concentration, sodium carbonate concentration, inoculums density, pH and incubation period for Escherichia coli reaction on succinic acid production. The result of first order factorial design showed that glycerol concentration, tryptone concentration, incubation period and pH had significant positive effect (p>0.001) to the reaction. Meanwhile, inoculums density and Na2CO3 concentration exhibited insignificant effect in the reaction. In addition, interaction between inoculums density of substrate concentration and tryptone concentration, glycerol concentration and Na2CO3 concentration, tryptone concentration and pH, Na2CO3 concentration and incubation period and inoculums density with pH gave significant effects (p<0.001) to succinic acid production.