Arruda Priscila V, Felipe Maria G A
Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Estrada Municipal do Campinho s/n, P.O. Box 116, Lorena, SP 12602-810, Brazil.
Curr Microbiol. 2009 Mar;58(3):274-8. doi: 10.1007/s00284-008-9321-7. Epub 2008 Nov 25.
The effect of glycerol on xylose-to-xylitol bioconversion by Candida guilliermondii was evaluated by its addition (0.7 and 6.5 g/l) to semidefined media (xylose as a substrate). The glycerol concentrations were chosen based on the amounts produced during previous studies on xylitol production by C. guilliermondii. Medium without glycerol addition (control) and medium containing glycerol (53 g/l) in substitution to xylose were also evaluated. According to the results, the addition of 0.7 g/l glycerol to the fermentation medium favored not only the yield (Y(P/S)=0.78 g/g) but also the xylitol productivity (Q(P)=1.13 g/l/h). During the xylose-to-xylitol bioconversion, the formation of byproducts (glycerol and ethanol) was observed for all conditions employed. In relation to the cellular growth, glycerol as the only carbon source for C. guilliermondii was better than xylose or xylose and glycerol mixtures, resulting in a maximum cellular concentration (5.34 g/l).
通过向半限定培养基（以木糖为底物）中添加甘油（0.7和6.5 g/L），评估了甘油对季也蒙毕赤酵母将木糖转化为木糖醇生物转化的影响。甘油浓度是根据之前关于季也蒙毕赤酵母生产木糖醇的研究中产生的量来选择的。还评估了不添加甘油的培养基（对照）和用甘油（53 g/L）替代木糖的培养基。根据结果，向发酵培养基中添加0.7 g/L甘油不仅有利于产率（Y(P/S)=0.78 g/g），也有利于木糖醇生产率（Q(P)=1.13 g/L/h）。在木糖向木糖醇的生物转化过程中，在所采用的所有条件下均观察到副产物（甘油和乙醇）的形成。关于细胞生长，甘油作为季也蒙毕赤酵母的唯一碳源优于木糖或木糖与甘油的混合物，产生的最大细胞浓度为（5.34 g/L）。
