Effect of pH on metabolite excretion and cell morphology of Euglena gracilis under dark, anaerobic conditions
Effect of pH on metabolite excretion and cell morphology of Euglena gracilis under dark, anaerobic conditions
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黑暗、厌氧条件下 pH 对眼虫代谢物排泄和细胞形态的影响
DOI：
10.1016/j.algal.2020.102084
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Osanai Takashi
中科院分区：
文献类型：
--
作者：
Yoshioka Kazumasa;Suzuki Kengo;Osanai Takashi
细小眼虫是一种在水生环境中发现的单细胞真核微藻。它可以适应其形态以响应各种环境应激因素，例如温度、光和离子浓度的变化。纤细细胞在黑暗和厌氧条件下分泌琥珀酸和氨基酸；然而，关于这些条件对大肠杆菌细胞形态的影响的研究很少。迄今为止已进行了 gracilili 。在本研究中，我们旨在评估 pH 对大肠杆菌中琥珀酸、谷氨酰胺和谷氨酸排泄的影响。 gracilis 以及这些代谢物的水平与黑暗、厌氧条件下的细胞形态之间的相关性。 E.琥珀酸、谷氨酰胺和谷氨酸的排泄。纤细化 pH 值依赖性。酸性条件下（pH 3-5）谷氨酸和谷氨酰胺的排泄增加。相反，琥珀酸的产生取决于缓冲盐；使用 GTA [3,3-二甲基-戊二酸、三（羟甲基）氨基甲烷和 2-氨基-2-甲基-1,3-丙二醇] 或柠檬酸盐缓冲液时，琥珀酸盐水平较高，而使用乙酸盐缓冲液（pH 4 或 5）时，琥珀酸盐水平较低。酸性条件下梭形细胞数量趋于增加，细胞长宽比与谷氨酰胺和谷氨酸水平呈正相关。细胞密度增加，尤其是谷氨酰胺和琥珀酸产量增加；特别是，琥珀酸滴度达到 1.5 g/L。我们的研究结果表明，培养基的 pH 值会改变大肠杆菌的代谢物产生和细胞形态。黑暗、厌氧条件下的薄壁细胞。对真核发酵的更深入了解将有利于生物精炼行业，主要用于利用厌氧微生物生产增值产品。
Euglena gracilis is a unicellular eukaryotic microalga found in aquatic environments. It can acclimate its morphology in response to various environmental stress factors such as changes in temperature, light, and ion concentrations.E. graciliscells excrete succinate and amino acids under dark and anaerobic conditions; however, only a few studies on the effect of these conditions on the cell morphology ofE. gracilishave been conducted thus far. In the present study, we aimed to evaluate the effects of pH on succinate, glutamine and glutamate excretion inE. gracilisand the correlation between the levels of these metabolites and cell morphology under dark, anaerobic conditions. The excretion of succinate, glutamine and glutamate byE. gracilisis pH dependent. Glutamate and glutamine excretion increased under acidic conditions (pH 3–5). On the contrary, succinate production depended on the buffer salts; succinate levels were higher when GTA [3,3-dimethyl-glutaric acid, tris(hydroxymethyl)aminomethane, and 2-amino-2-methyl-1,3-propanediol] or citrate buffer were used and were lower when acetate buffer was used (pH 4 or 5). The number of spindle cells tended to increase under acidic conditions and the aspect ratio of the cells was positively correlated with glutamine and glutamate levels. Increase in cell density particularly enhanced glutamine and succinate production; in particular, the succinate titer reached 1.5 g/L. Our findings indicate that pH of the media alters metabolite production and cell morphology ofE. graciliscells under dark, anaerobic conditions. A deeper understanding of eukaryotic fermentation will benefit the biorefinery industry, mainly for the production of value-added products using anaerobic microorganisms.
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影响因子：
2.2
作者：
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影响因子：
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影响因子：
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