Department of Chemical, Environmental and Material Engineering, University of Jaén, Jaén, Spain.
Molecular Biology and Biochemical Engineering Department, Chemical Engineering Area, University of Pablo de Olavide, Seville, Spain.
Prep Biochem Biotechnol. 2022;52(6):627-639. doi: 10.1080/10826068.2021.1983829. Epub 2021 Oct 25.
has been employed to study, initially, the influence of the oxygen availability on D-xylose to xylitol fermentation, as this parameter is considered as one of the most critical variables for this bio alcohol accumulation. Apart from the air supplied in the fermentation process through the stirring vortex (0.0 v/v/min), additional aeration rates (0.1-2.0 v/v/min) effects were discussed. Furthermore, a change in the fermentative medium composition as well as a comparative analysis of behavior with respect to fermentation of D-glucose and D-xylose mixtures solutions, with the aim of producing both xylitol and ethanol bioproducts, were performed. For these purposes, specific growth rates, biomass productivities, specific substrate-uptake rates, overall biomass yields, specific xylitol formation rates and overall xylitol yields values have been calculated, applying a differential method to the kinetic data. Aeration influence was clearly evinced since a faster D-xylose metabolism, for aeration values close to 1.0 v/v/min, was noted. This yeast exhibited a sequential substrate consumption, firstly D-glucose and then D-xylose. The maximum xylitol yield (0.32 kg kg) was obtained for 0.5 v/v/min airflow, remarking a significant reduction of this parameter for both above and below the quoted air supply value.
已采用该方法研究初始阶段氧可用性对 D-木糖向木糖醇发酵的影响，因为该参数被认为是这种生物酒精积累的最关键变量之一。除了发酵过程中通过搅拌涡流（0.0 v/v/min）供应的空气外，还讨论了其他曝气率（0.1-2.0 v/v/min）的影响。此外，还改变了发酵培养基的组成，并对 D-葡萄糖和 D-木糖混合溶液发酵的行为进行了对比分析，目的是同时生产木糖醇和乙醇生物制品。为此，应用差量法对动力学数据进行了计算，得到了比生长速率、生物量产率、比底物摄取速率、总生物量产率、比木糖醇形成速率和总木糖醇产率值。曝气的影响很明显，因为在接近 1.0 v/v/min 的曝气值下，D-木糖的代谢速度更快。该酵母表现出顺序消耗底物的特性，首先消耗 D-葡萄糖，然后消耗 D-木糖。在 0.5 v/v/min 气流下获得了最大的木糖醇产率（0.32 kg kg），与引用的供气值上下相比，该参数显著降低。
