CHARACTERIZATION OF XYLOSE UPTAKE IN THE YEASTS PICHIA-HEEDII AND PICHIA-STIPITIS
CHARACTERIZATION OF XYLOSE UPTAKE IN THE YEASTS PICHIA-HEEDII AND PICHIA-STIPITIS
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DOI：
10.1128/aem.55.1.159-164.1989
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发表时间：
1989-01-01
影响因子：
4.4
通讯作者：
BISSON, LF
中科院分区：
文献类型：
--
作者：
DOES, AL;BISSON, LF
在高效木糖发酵罐树干毕赤酵母和更易于基因操作的严格呼吸酵母毕赤酵母中研究了木糖吸收动力学。两种酵母都表现出不止一种木糖摄取系统，但底物亲和力不同。两种生物体的高亲和力木糖摄取Km与酿酒酵母的高效高亲和力葡萄糖摄取系统相似。在 P. heedii 中，低亲和力木糖摄取随着 2% 木糖生长而增强，但木糖含量为 0.05% 时则不然，而高亲和力木糖摄取则减少。与葡萄糖摄取相反，胡桃木的木糖摄取受到二硝基苯酚的抑制。二硝基苯酚抑制树干毕赤酵母对葡萄糖和木糖的吸收。 P. heedii 中 100 倍摩尔过量的木糖不会抑制葡萄糖的摄取。这表明胡桃木中的木糖摄取是通过不同于葡萄糖摄取的载体系统进行的。
The kinetics of xylose uptake were investigated in the efficient xylose fermenter Pichia stipitis and in the more readily genetically manipulated, strictly respiratory yeast Pichia heedii. Both yeasts demonstrated more than one xylose uptake system, differing in substrate affinity. The Km of high-affinity xylose uptake in both organisms was similar to that of the efficient high-affinity glucose uptake system of Saccharomyces cerevisiae. In P. heedii, low-affinity xylose uptake was enhanced with growth on 2% but not 0.05% xylose and high-affinity uptake was reduced. In contrast to glucose uptake, xylose uptake in P. heedii was inhibited by dinitrophenol. Dinitrophenol inhibited both glucose and xylose uptake by P. stipitis. Glucose uptake was not inhibited by a 100-fold molar excess of xylose in P. heedii. It is suggested that xylose uptake in P. heedii is via a carrier system(s) distinct from those for glucose uptake.