Respiration-dependent utilization of sugars in yeasts: a determinant role for sugar transporters
Respiration-dependent utilization of sugars in yeasts: a determinant role for sugar transporters
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DOI：
10.1128/jb.184.2.427-432.2002
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发表时间：
2002-01-01
影响因子：
3.2
通讯作者：
Donnini, C
中科院分区：
文献类型：
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作者：
Goffrini, P;Ferrero, I;Donnini, C
在许多酵母物种中，包括乳酸克鲁维酵母（Kluyveromyces lactis），某些糖（如半乳糖、棉子糖和麦芽糖）上的生长仅在呼吸条件下发生。如果呼吸作用被抑制剂、突变或厌氧作用所阻断，则生长不会发生。利用某些糖对呼吸作用的这种明显依赖性常常被怀疑与糖摄取步骤的机制有关。我们假设在许多酵母物种中，这些糖的渗透酶活性不足以确保发酵生长所必需的高底物流量。通过引入额外的糖通透酶基因，我们获得了K。乳酸菌菌株能够在没有呼吸的情况下在半乳糖和棉子糖上生长。高剂量的通透酶和麦芽糖酶基因确实是K.乳酸菌细胞在没有呼吸的情况下在麦芽糖上生长。这些结果有力地表明，糖的吸收步骤是主要的瓶颈，在发酵同化某些糖在K。乳酸菌，可能还有许多其他酵母菌。
In many yeast species, including Kluyveromyces lactis, growth on certain sugars (such as galactose, raffinose, and maltose) occurs only, under respiratory conditions. If respiration is blocked by inhibitors, mutation, or anaerobiosis, growth does not take place. This apparent dependence on respiration for the utilization of certain sugars has often been suspected to be associated with the mechanism of the sugar uptake step. We hypothesized that in many yeast species, the permease activities for these sugars are not sufficient to ensure the high substrate flow that is necessary for fermentative growth. By introducing additional sugar permease genes, we have obtained K. lactis strains that were capable of growing on galactose and raffinose in the absence of respiration. High dosages of both the permease and maltase genes were indeed necessary for K. lactis cells to grow on maltose in the absence of respiration. These results strongly suggest that the sugar uptake step is the major bottleneck in the fermentative assimilation of certain sugars in K. lactis and probably in many other yeasts.