In ethanol fermentation of Saccharomyces cerevisiae （S. cerevisiae）, glycerol is one of the main by-products. The purpose of this investigation was to increase ethanol yield through minimizing glycerol yield by usin...In ethanol fermentation of Saccharomyces cerevisiae （S. cerevisiae）, glycerol is one of the main by-products. The purpose of this investigation was to increase ethanol yield through minimizing glycerol yield by using mutants in which FPS1 encoding a channel protein that mediates glycerol export and GPD2 encoding one of glycerol-3-phosphate dehydrogenase were knocked-out using one-step gene replacement. GLT1 and GLN1 that encode glutamate synthase and glutamine synth.etase, respectively,were overexpressed using two-step gene replacment in fpsl△gpd2△ mutant.The fermentation properties of ZAL69（fpsl△：：LEU2 gpd2△：：URA3） and ZAL808 （fps1△：：LEU2 gpd2△：：URA3 PPGK1-GLT1 PPGK1-GLN1） under microaerobic conditions were investigated and compared with those of wild type（DC124）. Consumption of glucose, yield of ethanol, yield of glycerol, acetic acid, and pyruvic acid were monitored. Compared with wild type, the ethanol yield of ZAL69 and ZAL808 were improved by. 13.17% and 6.66 %, respectively, whereas glycerol yield decreased by 37.4 % and 41.7 %. Meanwhile, acetic acia yield and pyruvic acid yield aecreasea aramatlcally comparea to wild type. Our results indicate that FPS1 and GPD2 deletion of S. cerevisiae resulted in reduced glycerol yield and increased ethanol yield, but simultaneous overexpression of GLT1 and GLN1 infps1△gpd2△ mutant did not have a higher ethanol yield thanfps1△gpd2△ mutant.展开更多
目的探讨组蛋白去乙酰化酶(histone deacetylase,HDAC)2在蛛网膜下腔出血(subarachnoid hemorrhage,SAH)模型小鼠谷氨酸转运体(glutamate transporter,GLT)的调节中的作用,以及HDAC2抑制剂(HDAC2i)对SAH后认知障碍的保护作用。方法采用...目的探讨组蛋白去乙酰化酶(histone deacetylase,HDAC)2在蛛网膜下腔出血(subarachnoid hemorrhage,SAH)模型小鼠谷氨酸转运体(glutamate transporter,GLT)的调节中的作用,以及HDAC2抑制剂(HDAC2i)对SAH后认知障碍的保护作用。方法采用颈内动脉穿刺法建立小鼠SAH模型,Western Blot和免疫荧光染色检测SAH小鼠海马区各亚型HDAC、GLT1的表达水平及其在星形胶质细胞中的定位。用Morris水迷宫和旷场行为学试验检测新型特异性HDAC2i腹腔注射10 d对SAH小鼠学习记忆、抑郁情绪的改善作用。结果与假手术组(Sham)相比,SAH组小鼠各时间点海马组织星形胶质细胞的GLT1表达水平降低( P <0.05-0.01),各亚型HDAC表达水平增高( P <0.05-0.01),HDAC2变化最为显著;HDAC2i治疗后SAH小鼠水迷宫训练逃逸时间显著降低( P <0.05),目标象限活动时间增加( P <0.05)。同时HDAC2i改善SAH小鼠行为学异常的作用又可以被GLT1拮抗剂阻断。结论HDAC2可能通过调控星形胶质细胞的GLT1表达,参与SAH后小鼠认知障碍的调节。特异性HDAC2i可能具有改善SAH后认知障碍的作用。展开更多
基金the National High Technology Research and Development Program of China(2002AA647040)
文摘In ethanol fermentation of Saccharomyces cerevisiae （S. cerevisiae）, glycerol is one of the main by-products. The purpose of this investigation was to increase ethanol yield through minimizing glycerol yield by using mutants in which FPS1 encoding a channel protein that mediates glycerol export and GPD2 encoding one of glycerol-3-phosphate dehydrogenase were knocked-out using one-step gene replacement. GLT1 and GLN1 that encode glutamate synthase and glutamine synth.etase, respectively,were overexpressed using two-step gene replacment in fpsl△gpd2△ mutant.The fermentation properties of ZAL69（fpsl△：：LEU2 gpd2△：：URA3） and ZAL808 （fps1△：：LEU2 gpd2△：：URA3 PPGK1-GLT1 PPGK1-GLN1） under microaerobic conditions were investigated and compared with those of wild type（DC124）. Consumption of glucose, yield of ethanol, yield of glycerol, acetic acid, and pyruvic acid were monitored. Compared with wild type, the ethanol yield of ZAL69 and ZAL808 were improved by. 13.17% and 6.66 %, respectively, whereas glycerol yield decreased by 37.4 % and 41.7 %. Meanwhile, acetic acia yield and pyruvic acid yield aecreasea aramatlcally comparea to wild type. Our results indicate that FPS1 and GPD2 deletion of S. cerevisiae resulted in reduced glycerol yield and increased ethanol yield, but simultaneous overexpression of GLT1 and GLN1 infps1△gpd2△ mutant did not have a higher ethanol yield thanfps1△gpd2△ mutant.
文摘目的探讨组蛋白去乙酰化酶(histone deacetylase,HDAC)2在蛛网膜下腔出血(subarachnoid hemorrhage,SAH)模型小鼠谷氨酸转运体(glutamate transporter,GLT)的调节中的作用,以及HDAC2抑制剂(HDAC2i)对SAH后认知障碍的保护作用。方法采用颈内动脉穿刺法建立小鼠SAH模型,Western Blot和免疫荧光染色检测SAH小鼠海马区各亚型HDAC、GLT1的表达水平及其在星形胶质细胞中的定位。用Morris水迷宫和旷场行为学试验检测新型特异性HDAC2i腹腔注射10 d对SAH小鼠学习记忆、抑郁情绪的改善作用。结果与假手术组(Sham)相比,SAH组小鼠各时间点海马组织星形胶质细胞的GLT1表达水平降低( P <0.05-0.01),各亚型HDAC表达水平增高( P <0.05-0.01),HDAC2变化最为显著;HDAC2i治疗后SAH小鼠水迷宫训练逃逸时间显著降低( P <0.05),目标象限活动时间增加( P <0.05)。同时HDAC2i改善SAH小鼠行为学异常的作用又可以被GLT1拮抗剂阻断。结论HDAC2可能通过调控星形胶质细胞的GLT1表达,参与SAH后小鼠认知障碍的调节。特异性HDAC2i可能具有改善SAH后认知障碍的作用。
