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Piotr Hapeta Patrycja Szczepa&#x;ska Tadeusz Witkowski Jean-Marc Nicaud Anne-Marie Crutz-Le Coq Zbigniew Lazar 《International journal of molecular sciences》2021,22(17)
The development of efficient bioprocesses requires inexpensive and renewable substrates. Molasses, a by-product of the sugar industry, contains mostly sucrose, a disaccharide composed of glucose and fructose, both easily absorbed by microorganisms. Yarrowia lipolytica, a platform for the production of various chemicals, can be engineered for sucrose utilization by heterologous invertase expression, yet the problem of preferential use of glucose over fructose remains, as fructose consumption begins only after glucose depletion what significantly extends the bioprocesses. We investigated the role of hexose transporters and hexokinase (native and fructophilic) in this preference. Analysis of growth profiles and kinetics of monosaccharide utilization has proven that the glucose preference in Y. lipolytica depends primarily on the affinity of native hexokinase for glucose. Interestingly, combined overexpression of either hexokinase with hexose transporters significantly accelerated citric acid biosynthesis and enhanced pentose phosphate pathway leading to secretion of polyols (31.5 g/L vs. no polyols in the control strain). So far, polyol biosynthesis was efficient in glycerol-containing media. Moreover, overexpression of fructophilic hexokinase in combination with hexose transporters not only shortened this process to 48 h (84 h for the medium with glycerol) but also allowed to obtain 23% more polyols (40 g/L) compared to the glycerol medium (32.5 g/L). 相似文献
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目的:研究鲨肝刺激物质的降血糖作用机制。方法:采用四氧嘧啶糖尿病小鼠模型, 观察鲨肝刺激物质对糖尿病小鼠空腹血糖、果糖胺、胰岛素、肝糖原、己糖激酶、过氧化脂质等生化指标的影响。采用离体培养原代小鼠肝细胞, 研究鲨肝刺激物质对四氯化碳、对乙酰氨基酚所致肝细胞损伤的作用。结果:鲨肝刺激物质显著降低糖尿病小鼠空腹血糖和果糖胺水平, 增加血清胰岛素、肝糖原含量, 提高己糖激酶活性, 减轻四氯化碳、对乙酰氨基酚对原代小鼠肝细胞的损伤。结论:鲨肝刺激物质降血糖作用机制与保护胰岛和肝细胞功能、提高己糖激酶活性、促进肝糖原合成和抗氧化损伤作用密切相关。 相似文献