[ Objective] The research aimed to explore the efficiency of ethanol production under the optimal conditions of separate hydrolysis and fermentation （SHF） and simultaneous saccharification and fermentation （SSF）. ...[ Objective] The research aimed to explore the efficiency of ethanol production under the optimal conditions of separate hydrolysis and fermentation （SHF） and simultaneous saccharification and fermentation （SSF）. [ Method ] Under the optimal conditions of hydrolysis and fermenta- tion, SHF and SSF process were designed respectively. SHF process was conducted under the optimal conditions of hydrolysis and fermentation separately, while SSF process was carried out at the optimum temperature of hydrolysis and fermentation. [ Result] In SHF process, the efficiency of ethanol production was similar during both supematant and mixture fermentation, and yeast was more active during the mixture fermentation. In SSF process, the efficiency of ethanol production was higher at 35 ℃, and the production of xylose was higher than that in hydrolysis process. [ Conclusion] Under the experimental conditions, the efficiency of ethanol production during simultaneous saccharification and fermentation was higher than that during separate hydrolysis and fermentation.展开更多
Egypt faces a high population growth rate nowadays, which demands for an increase in agricultural production efficiency. Consequently, agricultural field residues will increase. Rice straw is one of the main agricultu...Egypt faces a high population growth rate nowadays, which demands for an increase in agricultural production efficiency. Consequently, agricultural field residues will increase. Rice straw is one of the main agriculture residues in Egypt. So this study was performed on rice straw as a resource for production of bioethanol. Eight microbial isolates, five yeasts and three fungi were isolated from rice straw. Yeast isolates were selected for their ability to utilize different sugars and cellulose. Chipped and grinded rice straw was subjected to different pretreatment methods physically through steam treatment by autoclaving and different doses of gamma γ irradiation (50 and 70 Mrad). Autoclaved pretreated rice straw was further enzymatically treated throughout solid state fermentation process by different fungal isolates;F68, F94 and F98 producing maximum total reducing sugars of 12.62, 13.58, 17.00 g/L, respectively. Bioethanol production by separate microbial hydrolysis and fermentation (SHF) process of rice straw hydrolysate was performed by the two selected fungal isolates;Trichoderma viride F94 and Aspergillus terreus F98 and two yeast isolates (Y26 and Y39). The two yeast isolates have been identified by 18S, RNA as Candida tropicalis Y26 and Saccharomyces cerevisiae Y39. SHF processes by F94 and Y26 produced 45 gallon/ton rice straw while that of F98 and Y39 produced 50 gallon/ton rice straw.展开更多
A greener method has been tested to utilize algal biomass as a feedstock to produce bio-oil in addition to acetone,butanol,and ethanol(ABE)products.Various hydrolysis treatments were used prior to fermentation includi...A greener method has been tested to utilize algal biomass as a feedstock to produce bio-oil in addition to acetone,butanol,and ethanol(ABE)products.Various hydrolysis treatments were used prior to fermentation including combination of thermal,chemical,and enzymatic,which resulted in maximum sugar release of 27.78 g/L.Bio-based terpenes was used instead of common toxic chemicals together with Clostridial fustants to produce bio-alcoholic fuels.Protoplast fusion technique were used to produce the novel Clostridia fusants(C.beijernickii+C.thermocellum and C.acetobutylicum+C.thermocellocum).Fused strains were then subjected to UV radiation for strain enhancement.Final fusansts showed clear improvement in thermal stability and resistance to biobutanol toxicity.Fermentation experiments showed maximum biobutanol final production of 7.98 g/L using CbCt versus 7.39 g/L using CaCt.Oil extraction from virgin algae was tested using a green,bio-based approach using ter-penes with ultrasonication and green Bligh and Dyer method,separately.In preliminary study on algal biomass,the combinations of ultrasonication followed by the green Bligh and Dyer have resulted in oil yield of 46.27%(d-limonene)and 39.85%(p-cymene).Oil extraction from an algae sample following fermentation using the combined extraction method resulted in significantly higher oil yield of 65.04%.展开更多
基金Supported by National Science and Technology Key Project of Water Pollution Control and Management(2009ZX07101-015-03)
文摘[ Objective] The research aimed to explore the efficiency of ethanol production under the optimal conditions of separate hydrolysis and fermentation （SHF） and simultaneous saccharification and fermentation （SSF）. [ Method ] Under the optimal conditions of hydrolysis and fermenta- tion, SHF and SSF process were designed respectively. SHF process was conducted under the optimal conditions of hydrolysis and fermentation separately, while SSF process was carried out at the optimum temperature of hydrolysis and fermentation. [ Result] In SHF process, the efficiency of ethanol production was similar during both supematant and mixture fermentation, and yeast was more active during the mixture fermentation. In SSF process, the efficiency of ethanol production was higher at 35 ℃, and the production of xylose was higher than that in hydrolysis process. [ Conclusion] Under the experimental conditions, the efficiency of ethanol production during simultaneous saccharification and fermentation was higher than that during separate hydrolysis and fermentation.
文摘Egypt faces a high population growth rate nowadays, which demands for an increase in agricultural production efficiency. Consequently, agricultural field residues will increase. Rice straw is one of the main agriculture residues in Egypt. So this study was performed on rice straw as a resource for production of bioethanol. Eight microbial isolates, five yeasts and three fungi were isolated from rice straw. Yeast isolates were selected for their ability to utilize different sugars and cellulose. Chipped and grinded rice straw was subjected to different pretreatment methods physically through steam treatment by autoclaving and different doses of gamma γ irradiation (50 and 70 Mrad). Autoclaved pretreated rice straw was further enzymatically treated throughout solid state fermentation process by different fungal isolates;F68, F94 and F98 producing maximum total reducing sugars of 12.62, 13.58, 17.00 g/L, respectively. Bioethanol production by separate microbial hydrolysis and fermentation (SHF) process of rice straw hydrolysate was performed by the two selected fungal isolates;Trichoderma viride F94 and Aspergillus terreus F98 and two yeast isolates (Y26 and Y39). The two yeast isolates have been identified by 18S, RNA as Candida tropicalis Y26 and Saccharomyces cerevisiae Y39. SHF processes by F94 and Y26 produced 45 gallon/ton rice straw while that of F98 and Y39 produced 50 gallon/ton rice straw.
基金Authors would like to acknowledge financial support from Agricul-ture and Agri-Food Canada,the Natural Sciences and Engineering Re-search Council of Canada(NSERC),and the Faculty of Engineering and Architectural Science at Toronto Metropolitan University in Toronto,Canada.
文摘A greener method has been tested to utilize algal biomass as a feedstock to produce bio-oil in addition to acetone,butanol,and ethanol(ABE)products.Various hydrolysis treatments were used prior to fermentation including combination of thermal,chemical,and enzymatic,which resulted in maximum sugar release of 27.78 g/L.Bio-based terpenes was used instead of common toxic chemicals together with Clostridial fustants to produce bio-alcoholic fuels.Protoplast fusion technique were used to produce the novel Clostridia fusants(C.beijernickii+C.thermocellum and C.acetobutylicum+C.thermocellocum).Fused strains were then subjected to UV radiation for strain enhancement.Final fusansts showed clear improvement in thermal stability and resistance to biobutanol toxicity.Fermentation experiments showed maximum biobutanol final production of 7.98 g/L using CbCt versus 7.39 g/L using CaCt.Oil extraction from virgin algae was tested using a green,bio-based approach using ter-penes with ultrasonication and green Bligh and Dyer method,separately.In preliminary study on algal biomass,the combinations of ultrasonication followed by the green Bligh and Dyer have resulted in oil yield of 46.27%(d-limonene)and 39.85%(p-cymene).Oil extraction from an algae sample following fermentation using the combined extraction method resulted in significantly higher oil yield of 65.04%.
