The determination of optimum values of volumetric oxygen transfer coefficient (k_La) for Spathaspora passalidarum is an important aspect for the optimization of ethanol production from pentoses since oxygen plays a key role on yeast metabolism. By studying the fermentation of a xylose and glucose mixture, the highest ethanol volumetric productivity was achieved at a k_La of 45 h⁻¹ (1.12 g_ethanol L⁻¹ h⁻¹), reducing the fermentation time to half when compared to other oxygen-limiting conditions that were considered optimum for other native strains, besides increasing xylose consumption rates. The high cell density fermentation showed to be a good strategy to be applied in industrial processes with S. passalidarum, enabling the complete exhaustion of a high initial substrate concentration (90 g L⁻¹) in less than 24 h, with a final ethanol titer of 28.61 (± 0.42) g L⁻¹. By performing a detailed investigation on oxidation–reduction potential (ORP), it was possible to conclude that the highest ethanol formation rates were registered at oxireduction potential values around − 100 mV, becoming an important parameter to be controlled when oxygen-limiting conditions are applied in industrial fermentations. The oxygen availability also affected the activity of enzyme XR and its preference for NADH or NADPH, directly affecting the activity of enzyme XDH and the redox imbalance on the xylose pathway. In addition, respirometric parameters were determined for the yeast S. passalidarum under an aerobic growth condition.

确定Passalidarum Spathaspora passalidarum的体积氧转移系数（k _L a）的最佳值是优化戊糖生产乙醇的重要方面，因为氧气在酵母代谢中起关键作用。通过研究木糖和葡萄糖混合物的发酵，在ak _L a为45 h ^-1时获得了最高的乙醇体积生产率（1.12 g_乙醇L ^-1  h ^-1），与提高其他木糖消耗速率的其他限氧条件相比，将发酵时间减少了一半，而其他限氧条件被认为对其他天然菌株是最佳的。高细胞密度发酵被证明是一种有效的策略，可用于帕氏链霉菌的工业生产，能够在不到24小时的时间内完全耗尽高浓度的初始底物（90 g L ^-1），并具有最终的乙醇滴定度的28.61（±0.42）g L ^-1。通过对氧化还原电位（ORP）进行详细研究，可以得出结论，最高乙醇生成速率记录在− 100 mV附近的氧化还原电位值上，成为在应用氧气限制条件时要控制的重要参数。在工业发酵中。氧的可用性还影响了XR酶的活性及其对NADH或NADPH的偏好，直接影响了XDH酶的活性和木糖途径上的氧化还原失衡。另外，在好氧生长条件下测定酵母帕氏链霉菌的呼吸测定参数。