For practical applications of bioethanol, the uses of both highly concentrated biomass materials and their effective fermentation by yeasts are indispensable in order to produce ethanol at low costs. However, as the s...For practical applications of bioethanol, the uses of both highly concentrated biomass materials and their effective fermentation by yeasts are indispensable in order to produce ethanol at low costs. However, as the saccharified products of those biomass generally contain abundant sugars, the yeasts are affected by the compounds and are inclined to decrease their physiological activities. In the process of fermentation, ethanol is gradually produced by the yeasts in the culture;the concentrated metabolic product also damages itself, and inhibition of the fermentation frequently occurs. The application of yeasts with high fermentative activities under stress pressures such as sugars and ethanol is thus desired for bioethanol production. In this study, various types of high-fermentative yeasts under stress pressures were isolated mainly from coastal waters in Japan and characterized. All yeast strains with high fermentative activities under 20% v/v ethanol were found to be Saccharomyces cerevisiae. The HK21 strain isolated from Tokyo Bay and identified as S. cerevisiae had the highest fermentation activity under 30% w/v sorbitol and under 20% v/v ethanol, and it produced approx. 70 g/l (9% v/v) ethanol from the 15% w/v glucose solution at 25 oC within 5 days.展开更多
In coastal areas with complicated flow movement, deposition and scour readily occur in submarine excavation projects. In this study, a smallscale model, with a high resolution in the vertical direction, was used to si...In coastal areas with complicated flow movement, deposition and scour readily occur in submarine excavation projects. In this study, a smallscale model, with a high resolution in the vertical direction, was used to simulate the tidal current around a submarine excavation project. The finite volume method was used to solve Navier-Stokes equations and the Reynolds stress transport equation, and the entire process of the tidal current was simulated with unstructured meshes, generated in the irregular shape area, and structured meshes, generated in other water areas.The meshes near the bottom and free surface were densified with a minimum layer thickness of 0.05 m. The volume of fluid method was used to track the free surface, the volume fraction of cells on the upstream boundary was obtained from the volume fraction of adjacent cells, and that on the downstream boundary was determined by the water level process. The numerical results agree with the observed data, and some conclusions can be drawn: after the foundation trench excavation, the flow velocity decreases quite a bit through the foundation trench, with reverse flow occurring on the lee slope in the foundation trench; the swirling flow impedes inflow, leading to the occurrence of dammed water above the foundation trench; the turbulent motion is stronger during ebbing than in other tidal stages, the range with the maximum value of turbulent viscosity, occurring on the south side of the foundation trench at maximum ebbing, is greater than those in other tidal stages in a tidal cycle, and the maximum value of Reynolds shear stress occurs on the south side of the foundation trench at maximum ebbing in a tidal cycle. The numerical calculation method shows a strong performance in simulation of the hydrodynamic characteristics of tidal currents in the foundation trench, providing a basis for submarine engineering construction in coastal areas.展开更多
为了评价不同藜麦种质资源的耐盐性差异,以123份藜麦种质资源为材料,设置4个盐浓度(100、150、250和350m M)进行苗期盐胁迫处理试验,并鉴定其盐胁迫表型。结果表明,分别有3、20和94份种质能够耐受350、250和150 m M浓度的盐胁迫,所有藜...为了评价不同藜麦种质资源的耐盐性差异,以123份藜麦种质资源为材料,设置4个盐浓度(100、150、250和350m M)进行苗期盐胁迫处理试验,并鉴定其盐胁迫表型。结果表明,分别有3、20和94份种质能够耐受350、250和150 m M浓度的盐胁迫,所有藜麦种质对100 m M盐处理均不敏感。之后选取可耐受350m M盐浓度的3份种质PI 614921、Ames 13726、Ames 13761和另外3个可耐受250 m M盐浓度的现代藜麦品种Pasto、Atlas和Riobamba进行全生育周期盐胁迫处理试验,盐浓度为100、150和250m M,检测盐处理后4周和收获期藜麦的株高、叶绿素含量、根系干重、地上部干重以及最终籽粒产量。结果表明,藜麦植株的各生理指标和盐处理浓度均呈显著负相关;藜麦根系干重受盐胁迫影响最大,籽粒产量所受影响最小。最后选取Pasto、Atlas和Riobamba在电导率为7.0 m S·cm-1的盐土耕地上进行株行距密度分别为5 cm×12.5 cm和5 cm×50 cm的小区试验,收获后检测各小区的产量。3个品种的折算产量最高分别可达2.18、2.48和2.26 t·hm-2,其中Atlas和Pasto适于高密度种植、Riobamba适于低密度种植。综上所述,藜麦是一种普遍耐盐的物种,但是不同种质的耐盐性之间存在较大差异;盐胁迫对于藜麦产量的影响较小,因此盐土环境下种植不会使其经济价值大幅度下降。藜麦良好的耐盐性和较高的经济价值对进一步科学合理地利用盐土资源具有重要意义。展开更多
文摘For practical applications of bioethanol, the uses of both highly concentrated biomass materials and their effective fermentation by yeasts are indispensable in order to produce ethanol at low costs. However, as the saccharified products of those biomass generally contain abundant sugars, the yeasts are affected by the compounds and are inclined to decrease their physiological activities. In the process of fermentation, ethanol is gradually produced by the yeasts in the culture;the concentrated metabolic product also damages itself, and inhibition of the fermentation frequently occurs. The application of yeasts with high fermentative activities under stress pressures such as sugars and ethanol is thus desired for bioethanol production. In this study, various types of high-fermentative yeasts under stress pressures were isolated mainly from coastal waters in Japan and characterized. All yeast strains with high fermentative activities under 20% v/v ethanol were found to be Saccharomyces cerevisiae. The HK21 strain isolated from Tokyo Bay and identified as S. cerevisiae had the highest fermentation activity under 30% w/v sorbitol and under 20% v/v ethanol, and it produced approx. 70 g/l (9% v/v) ethanol from the 15% w/v glucose solution at 25 oC within 5 days.
基金supported by the National Natural Science Foundation of China(Grant No.41406005)
文摘In coastal areas with complicated flow movement, deposition and scour readily occur in submarine excavation projects. In this study, a smallscale model, with a high resolution in the vertical direction, was used to simulate the tidal current around a submarine excavation project. The finite volume method was used to solve Navier-Stokes equations and the Reynolds stress transport equation, and the entire process of the tidal current was simulated with unstructured meshes, generated in the irregular shape area, and structured meshes, generated in other water areas.The meshes near the bottom and free surface were densified with a minimum layer thickness of 0.05 m. The volume of fluid method was used to track the free surface, the volume fraction of cells on the upstream boundary was obtained from the volume fraction of adjacent cells, and that on the downstream boundary was determined by the water level process. The numerical results agree with the observed data, and some conclusions can be drawn: after the foundation trench excavation, the flow velocity decreases quite a bit through the foundation trench, with reverse flow occurring on the lee slope in the foundation trench; the swirling flow impedes inflow, leading to the occurrence of dammed water above the foundation trench; the turbulent motion is stronger during ebbing than in other tidal stages, the range with the maximum value of turbulent viscosity, occurring on the south side of the foundation trench at maximum ebbing, is greater than those in other tidal stages in a tidal cycle, and the maximum value of Reynolds shear stress occurs on the south side of the foundation trench at maximum ebbing in a tidal cycle. The numerical calculation method shows a strong performance in simulation of the hydrodynamic characteristics of tidal currents in the foundation trench, providing a basis for submarine engineering construction in coastal areas.
基金the financial supports from the China Postdoctoral Science Foundation (No. 2021M700388)the Interdisciplinary Research Project for Young Teachers of USTB (Fundamental Research Funds for the Central Universities), China (No. FRF-IDRY-20-013)+1 种基金the Fundamental Research Funds for the Central Universities, China (No. FRF-TP-20-041A1)the National Natural Science Foundation of China (No. U2034206)。
基金江苏省农业科技自主创新资金项目[CX(14)2044]美国国际发展署Securing Water for Food Award-salt Tolerant Quinoa子项目(UR4443 B)
文摘为了评价不同藜麦种质资源的耐盐性差异,以123份藜麦种质资源为材料,设置4个盐浓度(100、150、250和350m M)进行苗期盐胁迫处理试验,并鉴定其盐胁迫表型。结果表明,分别有3、20和94份种质能够耐受350、250和150 m M浓度的盐胁迫,所有藜麦种质对100 m M盐处理均不敏感。之后选取可耐受350m M盐浓度的3份种质PI 614921、Ames 13726、Ames 13761和另外3个可耐受250 m M盐浓度的现代藜麦品种Pasto、Atlas和Riobamba进行全生育周期盐胁迫处理试验,盐浓度为100、150和250m M,检测盐处理后4周和收获期藜麦的株高、叶绿素含量、根系干重、地上部干重以及最终籽粒产量。结果表明,藜麦植株的各生理指标和盐处理浓度均呈显著负相关;藜麦根系干重受盐胁迫影响最大,籽粒产量所受影响最小。最后选取Pasto、Atlas和Riobamba在电导率为7.0 m S·cm-1的盐土耕地上进行株行距密度分别为5 cm×12.5 cm和5 cm×50 cm的小区试验,收获后检测各小区的产量。3个品种的折算产量最高分别可达2.18、2.48和2.26 t·hm-2,其中Atlas和Pasto适于高密度种植、Riobamba适于低密度种植。综上所述,藜麦是一种普遍耐盐的物种,但是不同种质的耐盐性之间存在较大差异;盐胁迫对于藜麦产量的影响较小,因此盐土环境下种植不会使其经济价值大幅度下降。藜麦良好的耐盐性和较高的经济价值对进一步科学合理地利用盐土资源具有重要意义。
