The increasing consumption of fossil fuels is contributing to global resource depletion and environmental pollution.Branched-chain higher alcohols,such as isopentanol and isobutanol,have attracted significant attentio...The increasing consumption of fossil fuels is contributing to global resource depletion and environmental pollution.Branched-chain higher alcohols,such as isopentanol and isobutanol,have attracted significant attention as next-generation biofuels.Biofuel production through microbial fermentation offers a green,sustainable,and renewable alternative to chemical synthesis.While enhanced production of isopentanol has been achieved in a variety of chassis,the fermentation yield has not yet reached levels suitable for industrial-scale production.In this study,we employed a continuous perturbation tool to construct a genome-scale perturbation library,combined with an isopentanol biosensor to screen for high-yielding mutants.We identified five highyielding mutants,each exhibiting an increased glucose conversion rate and isopentanol titer.The F2 strain,in particular,achieved an isopentanol titer of 1.57±0.014 g/L and a yield of 14.04±0.251 mg/g glucose(10%glucose),surpassing the highest values reported to date in engineered Saccharomyces cerevisiae.Systematic transcriptome analysis of the isopentanol synthesis,glycolysis,glycerol metabolism,and ethanol synthesis pathways revealed that MPC,OAC1,BAT2,GUT2,PDC6,and ALD4 are linked to efficient isopentanol production.Further analysis of differentially expressed genes(DEGs)identified 17 and 12 co-expressed DEGs(co-DEGs)in all mutants and the two second-round mutants,respectively.In addition,we validated the knockout or overexpression of key co-DEGs.Our results confirmed the critical roles of HOM3 and DIP5 in isopentanol production,along with genes associated with the aerobic respiratory chain(SDH3,CYT1,COX7,ROX1,and ATG41)and cofactor balance(BNA2 and NDE1).Additionally,functional analysis of the co-DEGs revealed that MAL33 is associated with the synthesis of branched-chain higher alcohols,expanding the intracellular metabolic network and offering new possibilities for green,cost-effective biofuel production.展开更多
High-pressure vapor-liquid phase equilibrium data for carbon dioxide＋ isopentanol were measured at tempera- tures of 313.2, 323.1, 333.5 and 343.4 K in the pressure range of 4.64 to 12.71 MPa in a variable-volume hig...High-pressure vapor-liquid phase equilibrium data for carbon dioxide＋ isopentanol were measured at tempera- tures of 313.2, 323.1, 333.5 and 343.4 K in the pressure range of 4.64 to 12.71 MPa in a variable-volume high-pressure visual cell. The experimental data were well correlated with Peng-Robinson equation of state （PR-EOS） together with van der Waals-2 two-parameter mixing rule, and the binary interaction parameters were obtained. Henry coefficients and partial molar volumes of CO2 at infinite dilution were estimated based on Krichevsky-Kasarnovsky equation, and Henry coefficients increase with increasing temperature, however, partial molar volumes of CO2 at infinite dilution are negative and the magnitudes decrease with temperature.展开更多
该研究通过比较D101、D204、AB-8、X-5四种大孔树脂对白葡萄酒中异戊醇的吸附效果,选取最佳大孔树脂,并从动力学的角度对其吸附及解吸特性进行研究。结果表明,D101大孔树脂振荡吸附效果最佳,对异戊醇的吸附率达53%,其在体积分数为60%的...该研究通过比较D101、D204、AB-8、X-5四种大孔树脂对白葡萄酒中异戊醇的吸附效果,选取最佳大孔树脂,并从动力学的角度对其吸附及解吸特性进行研究。结果表明,D101大孔树脂振荡吸附效果最佳,对异戊醇的吸附率达53%,其在体积分数为60%的乙醇中解吸48 h时对异戊醇的解吸率最高,达77%,具有良好的可重复利用性。D101大孔吸附树脂对白葡萄酒中异戊醇的吸附符合Langmuir吸附等温模型,可用准一级动力学吸附模型描述。采用流速为2 m L/min的体积分数为60%的乙醇对D101大孔树脂进行动态解吸时,36 h可达到最佳解吸效果,最大解吸率为84%。展开更多
基金supported by the National Key Research and Development Program of China(2020YFA0908300)the National Natural Science Foundation of China(32371497)the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-KJGG-021).
文摘The increasing consumption of fossil fuels is contributing to global resource depletion and environmental pollution.Branched-chain higher alcohols,such as isopentanol and isobutanol,have attracted significant attention as next-generation biofuels.Biofuel production through microbial fermentation offers a green,sustainable,and renewable alternative to chemical synthesis.While enhanced production of isopentanol has been achieved in a variety of chassis,the fermentation yield has not yet reached levels suitable for industrial-scale production.In this study,we employed a continuous perturbation tool to construct a genome-scale perturbation library,combined with an isopentanol biosensor to screen for high-yielding mutants.We identified five highyielding mutants,each exhibiting an increased glucose conversion rate and isopentanol titer.The F2 strain,in particular,achieved an isopentanol titer of 1.57±0.014 g/L and a yield of 14.04±0.251 mg/g glucose(10%glucose),surpassing the highest values reported to date in engineered Saccharomyces cerevisiae.Systematic transcriptome analysis of the isopentanol synthesis,glycolysis,glycerol metabolism,and ethanol synthesis pathways revealed that MPC,OAC1,BAT2,GUT2,PDC6,and ALD4 are linked to efficient isopentanol production.Further analysis of differentially expressed genes(DEGs)identified 17 and 12 co-expressed DEGs(co-DEGs)in all mutants and the two second-round mutants,respectively.In addition,we validated the knockout or overexpression of key co-DEGs.Our results confirmed the critical roles of HOM3 and DIP5 in isopentanol production,along with genes associated with the aerobic respiratory chain(SDH3,CYT1,COX7,ROX1,and ATG41)and cofactor balance(BNA2 and NDE1).Additionally,functional analysis of the co-DEGs revealed that MAL33 is associated with the synthesis of branched-chain higher alcohols,expanding the intracellular metabolic network and offering new possibilities for green,cost-effective biofuel production.
文摘High-pressure vapor-liquid phase equilibrium data for carbon dioxide＋ isopentanol were measured at tempera- tures of 313.2, 323.1, 333.5 and 343.4 K in the pressure range of 4.64 to 12.71 MPa in a variable-volume high-pressure visual cell. The experimental data were well correlated with Peng-Robinson equation of state （PR-EOS） together with van der Waals-2 two-parameter mixing rule, and the binary interaction parameters were obtained. Henry coefficients and partial molar volumes of CO2 at infinite dilution were estimated based on Krichevsky-Kasarnovsky equation, and Henry coefficients increase with increasing temperature, however, partial molar volumes of CO2 at infinite dilution are negative and the magnitudes decrease with temperature.
文摘该研究通过比较D101、D204、AB-8、X-5四种大孔树脂对白葡萄酒中异戊醇的吸附效果,选取最佳大孔树脂,并从动力学的角度对其吸附及解吸特性进行研究。结果表明,D101大孔树脂振荡吸附效果最佳,对异戊醇的吸附率达53%,其在体积分数为60%的乙醇中解吸48 h时对异戊醇的解吸率最高,达77%,具有良好的可重复利用性。D101大孔吸附树脂对白葡萄酒中异戊醇的吸附符合Langmuir吸附等温模型,可用准一级动力学吸附模型描述。采用流速为2 m L/min的体积分数为60%的乙醇对D101大孔树脂进行动态解吸时,36 h可达到最佳解吸效果,最大解吸率为84%。
