Growth and metabolite formation were studied in oxygen-limited chemostat cultures of Saccharomyces cerevisiae CBS 8066 and Candida utilis CBS 621 growing on glucose or maltose at a dilution rate of 0·1 h-1 With either glucose or maltose S. cerevisiae could be grown under dual limitation of oxygen and sugar. Respiration and alcoholic fermentation occurred simultaneously and the catabolite fluxes through these processes were dependent on the magnitude of the oxygen feed. C. utilis could also be grown under dual limitation of glucose and oxygen. However, at very low oxygen feed rates (i.e. below 4 mmol l-1 h-1) growth was limited by oxygen only, as indicated by the high residual glucose concentration in the culture. In contrast to S. cerevisiae, C. utilis could not be grown anaerobically at a dilution rate of 0·1 h-1. With C. utilis absence of oxygen resulted in wash-out, despite the presence of ergosterol and Tween-80 in the growth medium. The behaviour of C. utilis with respect to maltose utilization in oxygen-limited cultures was remarkable: alcoholic fermentation did not occur and the amount of maltose metabolized was dependent on the oxygen supply. Oxygen-limited cultures of C. utilis growing on maltose always contained high residual sugar concentrations. These observations throw new light on the so-called Kluyver effect. Apparently, maltose is a non-fermentable sugar for C. utilis CBS 621, despite the fact that it can serve as a substrate for growth of this facultatively fermentative yeast. This is not due to the absence of key enzymes of alcoholic fermentation. Pyruvate decarboxylase and alcohol dehydrogenase were present at high levels in maltose-utilizing cells of C. utilis grown under oxygen limitation. It is concluded that the Kluyver effect, in C. utilis growing on maltose, results from a regulatory mechanism that prevents the sugar from being fermented. Oxygen is not a key factor in this phenomenon since under oxygen limitation alcoholic fermentation of maltose was not triggered.
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机译：研究了生长和代谢物形成，在酿酒酵母中CBS 8066和念珠菌培养物中研究了氧气 - 限量化的培养物，并在葡萄糖或麦芽糖上以0·1 H-1的稀释率生长，以葡萄糖或麦芽糖S.酿酒酵母氧气和糖的双重限制。同时发生呼吸和酒精发酵，通过这些方法的抗粘合剂通量取决于氧气进料的大小。 C. Utilis也可以在葡萄糖和氧气的双重限制下生长。然而，在非常低的氧气进料速率下（即低于4mmol L-1 H-1）的生长仅受氧的限制，如培养物中的高残余葡萄糖浓度所示。与S.Cerevisiae相反，C.Utilis不能以0·1H-1的稀释率占厌氧。凭借C.Utilis缺乏氧气导致冲洗，尽管在生长培养基中存在Ergosterol和Tween-80。 C. Utilis关于氧气限制培养物中麦芽糖使用的行为显着：没有发生醇发酵，麦芽糖代谢量取决于氧气供应。在麦芽糖上生长的氧气限量培养始终含有高残留的糖浓度。这些观察结果在所谓的Kluyver效果上投掷新光。显然，麦芽糖是用于C.UTERIS CBS 621的不可发酵的糖，尽管它可以作为这种散热酵母生长的基材。这不是由于没有酒精发酵的关键酶。在氧气限制下，在氧气限制下生长的麦芽糖利用细胞，丙酮酸脱氢酶和醇脱氢酶存在于高水平。结论是，克鲁耶效应，在C. utilis上生长在麦芽糖上，由防止糖被发酵的调节机制产生。氧气不是这种现象中的关键因素，因为在氧气限制下，不触发麦芽糖的酒精发酵。
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