D-ribose is a unique, 5-carbon sugar that occurs naturally in all living cells. D-ribose has been used as a staring material for preparation of some certain medicines or just as a new nutraceutical that helps the body...D-ribose is a unique, 5-carbon sugar that occurs naturally in all living cells. D-ribose has been used as a staring material for preparation of some certain medicines or just as a new nutraceutical that helps the body naturally restore its energy level. The fermentative processes are the best for their relatively simple series of production steps and relatively cheap starting materials. However, because of the many impurities in glucose yeast water and its dark color, pretreatment and purification must be done to the fluid before D-ribose can be separated. In this paper, separation and purification of D-ribose was carried out using cation exchange resins, of which Ca2+ exchange resin had the best effect. The optimal condition for adsorption is a flow velocity of 0.5BV/h at adsorption temperature of 25℃. The optimal condition for desorption is a flow velocity of 0.5 BV/h at desorption temperature of 80℃.展开更多
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
Objective In this study, a pilot-scale investigation was conducted to examine and compare the biotoxicity of the organic compounds in effluents from five treatment processes (P1-P5) where each process was combination ...Objective In this study, a pilot-scale investigation was conducted to examine and compare the biotoxicity of the organic compounds in effluents from five treatment processes (P1-P5) where each process was combination of preoxidation (O3), coagulation, sedimentation, sand filtration, ozonation, granular activated carbon, biological activated carbon and chlorination (NaClO). Methods Organic compounds were extracted by XAD-2 resins and eluted with acetone and dichlormethane (DCM). The eluents were evaporated and redissolved with DMSO or DCM. The mutagenicity and estrogenicity of the extracts were assayed with the Ames test and yeast estrogen screen (YES assay), respectively. The organic compounds were detected by GC-MS. Results The results indicated that the mutation ratio (MR) of organic compounds in source water was higher than that for treated water. GC-MS showed that more than 48 organic compounds were identified in all samples and that treated water had significantly fewer types and concentrations of organic compounds than source water. Conclusion To different extents, all water treatment processes could reduce both the mutagenicity and estrogenicity, relative to source water. P2, P3, and P5 reduced mutagenicity more effectively, while P1 reduced estrogenicity, most effectively. Water treatment processes in this pilot plant had weak abilities to remove Di-n-butyl phthalate or 1, 2-Benzene dicarboxylic acid.展开更多
文摘D-ribose is a unique, 5-carbon sugar that occurs naturally in all living cells. D-ribose has been used as a staring material for preparation of some certain medicines or just as a new nutraceutical that helps the body naturally restore its energy level. The fermentative processes are the best for their relatively simple series of production steps and relatively cheap starting materials. However, because of the many impurities in glucose yeast water and its dark color, pretreatment and purification must be done to the fluid before D-ribose can be separated. In this paper, separation and purification of D-ribose was carried out using cation exchange resins, of which Ca2+ exchange resin had the best effect. The optimal condition for adsorption is a flow velocity of 0.5BV/h at adsorption temperature of 25℃. The optimal condition for desorption is a flow velocity of 0.5 BV/h at desorption temperature of 80℃.
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.
文摘Objective In this study, a pilot-scale investigation was conducted to examine and compare the biotoxicity of the organic compounds in effluents from five treatment processes (P1-P5) where each process was combination of preoxidation (O3), coagulation, sedimentation, sand filtration, ozonation, granular activated carbon, biological activated carbon and chlorination (NaClO). Methods Organic compounds were extracted by XAD-2 resins and eluted with acetone and dichlormethane (DCM). The eluents were evaporated and redissolved with DMSO or DCM. The mutagenicity and estrogenicity of the extracts were assayed with the Ames test and yeast estrogen screen (YES assay), respectively. The organic compounds were detected by GC-MS. Results The results indicated that the mutation ratio (MR) of organic compounds in source water was higher than that for treated water. GC-MS showed that more than 48 organic compounds were identified in all samples and that treated water had significantly fewer types and concentrations of organic compounds than source water. Conclusion To different extents, all water treatment processes could reduce both the mutagenicity and estrogenicity, relative to source water. P2, P3, and P5 reduced mutagenicity more effectively, while P1 reduced estrogenicity, most effectively. Water treatment processes in this pilot plant had weak abilities to remove Di-n-butyl phthalate or 1, 2-Benzene dicarboxylic acid.
