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Ana M R B Xavier - One of the best experts on this subject based on the ideXlab platform.
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Two-Stage Aeration Fermentation Strategy to Improve Bioethanol Production by Scheffersomyces stipitis
Fermentation, 2018Co-Authors: Tiago M. Henriques, Susana R. Pereira, Luísa S. Serafim, Ana M R B XavierAbstract:Hardwood spent sulfite liquor (HSSL) is a by-product from pulp industry with a high concentration of pentose sugars, besides some hexoses suitable for Bioethanol Production by Scheffersomyces stipitis. The establishment of optimal aeration process conditions that results in specific microaerophilic conditions required by S. stipitis is the main challenge for ethanol Production. The present study aimed to improve the ethanol Production from HSSL by S. stipitis through a two-stage aeration fermentation. Experiments with controlled dissolved oxygen tension (DOT) in the first stage and oxygen restriction in the second stage were carried out. The best results were obtained with DOT control at 50% in the first stage, where the increase of oxygen availability provided faster growth and higher biomass yield, and no oxygen supply with an agitation rate of 250 rpm, in the second stage allowed a successful induction of ethanol Production. Fermentation using 60% of HSSL (v/v) as substrate for S. stipitis provided a maximum specific growth rate of 0.07 h−1, an ethanol productivity of 0.04 g L h−1 and an ethanol yield of 0.39 g g−1, respectively. This work showed a successful two-stage aeration strategy as a promising aeration alternative for Bioethanol Production from HSSL by S. stipitis.
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Bioethanol Production from steam explosion pretreated and alkali extracted cistus ladanifer rockrose
Biochemical Engineering Journal, 2015Co-Authors: Miguel D Ferro, Maria C Fernandes, Ana F C Paulino, Janis Gravitis, Dmitry V Evtuguin, Sonia O Prozil, Ana M R B XavierAbstract:Abstract Biofuels are suitable alternatives to conventional and fossil fuels that pose serious environmental adverse effects to society. Bioethanol is the most promising biofuel and can be generated from lignocellulosic biomasses. Forest residues are outside the human food chain and inexpensive raw materials, but they need a previous pretreatment, in order to improve the cellulose accessibility for further bioconversion. The study of Bioethanol Production from rockrose pretreated by steam explosion (SE) was carried out employing separate enzymatic hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) approaches. Saccharification of untreated rockrose attained only 0.9% of sugars yield. However, the steam explosion pretreatment promoted the disruption of interfibrillar surfaces of fibers with partial degradation of lignin thus enhancing the accessibility of polysaccharides toward enzymatic hydrolysis. Alkaline extraction after steam explosion pretreatment of rockrose residue (R-SE-OH) led to the partial removal of lignin, hemicelluloses, and other degradation products from fibre surface allowing an increase of 75% in the glucose yield. Bioethanol Production in SSF mode was faster and slightly more efficient process than SHF providing the best results: ethanol concentration of 16.1 g L−1, fermentation efficiency of 69.8% and a yield of 22.1 g ethanol/100 g R-SE-OH.
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enzymatic saccharification and Bioethanol Production from cynara cardunculus pretreated by steam explosion
Bioresource Technology, 2015Co-Authors: Maria C Fernandes, Miguel D Ferro, Ana F C Paulino, Joana A S Mendes, Janis Gravitis, Dmitry V Evtuguin, Ana M R B XavierAbstract:Abstract The correct choice of the specific lignocellulosic biomass pretreatment allows obtaining high biomass conversions for biorefinery implementations and cellulosic Bioethanol Production from renewable resources. Cynara cardunculus (cardoon) pretreated by steam explosion (SE) was involved in second-generation Bioethanol Production using separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) processes. Steam explosion pretreatment led to partial solubilisation of hemicelluloses and increased the accessibility of residual polysaccharides towards enzymatic hydrolysis revealing 64% of sugars yield against 11% from untreated plant material. Alkaline extraction after SE pretreatment of cardoon (CSEOH) promoted partial removal of degraded lignin, tannins, extractives and hemicelluloses thus allowing to double glucose concentration upon saccharification step. Bioethanol fermentation in SSF mode was faster than SHF process providing the best results: ethanol concentration 18.7 g L −1 , fermentation efficiency of 66.6% and a yield of 26.6 g ethanol/100 g CSEOH or 10.1 g ethanol/100 g untreated cardoon.
Hyeunjong Bae - One of the best experts on this subject based on the ideXlab platform.
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a strategy for sequential fermentation by saccharomyces cerevisiae and pichia stipitis in Bioethanol Production from hardwoods
Renewable Energy, 2019Co-Authors: Younho Song, Bok Jae Park, Eun Jin Cho, Chan Song Park, Hyeunjong BaeAbstract:Abstract Climate change due to global warming has led to the expansion of deciduous forests. Increased product yields from hardwood provide an opportunity for the exploitation of biomass resources, such as Bioethanol. In this study, the enzymatic hydrolysis of various hardwoods pretreated using the hydrogen peroxide–acetic acid (HPAC) method was evaluated. Glucose and xylose were fermented sequentially to improve the Bioethanol Production from hardwood. The HPAC pretreatment significantly reduced lignin and improved the hydrolysis efficiency compared with no treatment. The enhanced hydrolysis efficiency contributed to an increase in the Bioethanol productivity, which was similar to that of simultaneous saccharification and fermentation, by reducing the processing time of separate hydrolysis and fermentation. The sequential fermentation of glucose and xylose via Saccharomyces cerevisiae and Pichia stipitis, respectively, improved ethanol Production by approximately 12% over conventional fermentation used with glucose alone. The results suggest that sequential fermentation can improve Bioethanol Production from hardwood.
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comparison of red microalgae porphyridium cruentum culture conditions for Bioethanol Production
Bioresource Technology, 2017Co-Authors: Ho Myeong Kim, Hyeunjong BaeAbstract:Abstract Microalgae biomass are useful resources in biofuel Production. The objective of this study was to evaluate Bioethanol Production in response to Porphyridium cruemtum culture conditions. Enzymatic hydrolysis of seawater P. cruemtum (SPC) and freshwater P. cruemtum (FPC, 1% substrate loading, w/v) resulted in glucose conversion yields of 89.8 and 85.3%, respectively, without any pretreatment. However, FPC hydrolysate was more efficiently converted to ethanol about 7.1% than SPC hydrolysate. The comparison of separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) showed that SSF processing is a superior method for Bioethanol Production from both SPC and FPC. Though SSF processing (5% substrate loading, w/v) in a 500-mL twin-neck round bottom flask, we achieved ethanol conversion yields of 65.4 and 70.3% from SPC and FPC, respectively, after 9 h. These findings indicate that P. cruemtum can grow in freshwater conditions and is an efficient candidate for Bioethanol Production.
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cellulosic Bioethanol Production from jerusalem artichoke helianthus tuberosus l using hydrogen peroxide acetic acid hpac pretreatment
Bioresource Technology, 2016Co-Authors: Younho Song, Ho Myeong Kim, Hyeunjong BaeAbstract:Jerusalem artichoke (JA) is recognized as a suitable candidate biomass crop for Bioethanol Production because it has a rapid growth rate and high biomass productivity. In this study, hydrogen peroxide-acetic acid (HPAC) pretreatment was used to enhance the enzymatic hydrolysis and to effectively remove the lignin of JA. With optimized enzyme doses, synergy was observed from the combination of three different enzymes (RUT-C30, pectinase, and xylanase) which provided a conversion rate was approximately 30% higher than the rate with from treatment with RUT-C30 alone. Fermentation of the JA hydrolyzates by Saccharomyces cerevisiae produced a fermentation yield of approximately 84%. Therefore, Jerusalem artichoke has potential as a bioenergy crop for Bioethanol Production.
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a low energy cost effective approach to fruit and citrus peel waste processing for Bioethanol Production
Applied Energy, 2015Co-Authors: In Seong Choi, Yoon Gyo Lee, Sarmir Kumar Khanal, Bok Jae Park, Hyeunjong BaeAbstract:Abstract Large quantities of fruit waste are generated from agricultural processes worldwide. This waste is often simply dumped into landfills or the ocean. Fruit waste has high levels of sugars, including sucrose, glucose, and fructose, that can be fermented for Bioethanol Production. However, some fruit wastes, such as citrus peel waste (CPW), contain compounds that can inhibit fermentation and should be removed for efficient Bioethanol Production. We developed a novel approach for converting single-source CPW (i.e., orange, mandarin, grapefruit, lemon, or lime) or CPW in combination with other fruit waste (i.e., banana peel, apple pomace, and pear waste) to produce Bioethanol. Two in-house enzymes were produced from Avicel and CPW and were tested with fruit waste at 12–15% (w/v) solid loading. The rates of enzymatic conversion of fruit waste to fermentable sugars were approximately 90% for all feedstocks after 48 h. We also designed a d -limonene removal column (LRC) that successfully removed this inhibitor from the fruit waste. When the LRC was coupled with an immobilized cell reactor (ICR), yeast fermentation resulted in ethanol concentrations (14.4–29.5 g/L) and yields (90.2–93.1%) that were 12-fold greater than products from ICR fermentation alone.
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Bioethanol Production from rice straw by popping pretreatment
Biotechnology for Biofuels, 2013Co-Authors: In Seong Choi, Ho Myeong Kim, Kyoung Hyoun Kim, Hyeunjong BaeAbstract:Background Rice straw has considerable potential as a raw material for Bioethanol Production. Popping pretreatment of rice straw prior to downstream enzymatic hydrolysis and fermentation was found to increase cellulose to glucose conversion efficiency. The aim of this study was to investigate the influence of popping pretreatment and determine the optimal enzyme loading using a surface response design.
Razif Harun - One of the best experts on this subject based on the ideXlab platform.
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exploring alkaline pre treatment of microalgal biomass for Bioethanol Production
Applied Energy, 2011Co-Authors: W S Y Jason, Razif Harun, Tamara Cherrington, Michael K DanquahAbstract:We have investigated, for the first time, the alkaline pre-treatment of microalgal biomass, from the species Chlorococcum infusionum, using NaOH for Bioethanol Production. This pre-treatment step aims to release and breakdown entrapped polysaccharides in the microalgae cell walls into fermentable subunits. Three parameters were examined here; the concentration of NaOH, temperature and the pre-treatment time. The Bioethanol concentration, glucose concentration and the cell size were studied in order to determine the effectiveness of the pre-treatment process. Microscopic analysis was performed to confirm cell rupturing, the highest glucose yield was determined to be 350mg/g, and the maximum Bioethanol yield obtained was 0.26g ethanol/g algae using 0.75% (w/v) of NaOH and 120°C for 30min. Overall, the alkaline pre-treatment method proved to be promising option to pre-treat microalgal biomass for Bioethanol Production.
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influence of acid pre treatment on microalgal biomass for Bioethanol Production
Process Biochemistry, 2011Co-Authors: Razif Harun, Michael K DanquahAbstract:Abstract The utilisation of microalgal biomass as feedstock for Bioethanol Production has been very promising owing to the large amounts of carbohydrates embedded in the physiology of the microalgal cell. This is coupled with the potential of microalgae to achieve targets required for high growth rate Bioethanol Production, climate change mitigation and economic growth. The high content of complex carbohydrates entrapped in the cell wall of the microalgae makes it essential to incorporate a pre-treatment stage to release and convert these complex carbohydrates into simple sugars prior to the fermentation process. Hence, this study explores the influence of acid exposure as a microalgal pre-treatment strategy for Bioethanol Production. Different parameters were investigated: acid concentration, temperature, microalgae loading and pre-treatment time. A central composite design technique was employed to optimize the acid pre-treatment conditions. Results showed that the highest Bioethanol concentration obtained was 7.20 g/L and this was achieved when the pre-treatment step was performed with 15 g/L of microalgae at 140 °C using 1% (v/v) of sulphuric acid for 30 min. In terms of ethanol yield, ∼52 wt% (g ethanol/g microalgae) maximum was obtained using 10 g/L of microalgae and 3% (v/v) of sulphuric acid under 160 °C for 15 min. The statistical analysis revealed amongst the parameters investigated that temperature is the most critical factor during acid pre-treatment of microalgae for Bioethanol Production.
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microalgal biomass as a fermentation feedstock for Bioethanol Production
Science & Engineering Faculty, 2010Co-Authors: Razif Harun, Michael K Danquah, Gareth M FordeAbstract:Background: The increasing cost of fossil fuels as well as the escalating social and industrial awareness of the environmental impacts associated with the use of fossil fuels has created the need for more sustainable fuel options. Bioethanol, produced from renewable biomass such as sugar and starch materials, is believed to be one of these options, and it is currently being harnessed extensively. However, the utilization of sugar and starch materials as feedstocks for Bioethanol Production creates a major competition with the food market in terms of land for cultivation, and this makes Bioethanol from these sources economically less attractive. Result: This study explores the suitability of microalgae (Chlorococum sp.) as a substrate for Bioethanol Production via yeast (Saccharomycesbayanus)under different fermentation conditions. Results show a maximum ethanol concentration of 3.83 g L -1 obtained from 10 g L-1 of lipid-extracted microalgae debris. Conclusion: This productivity level (∼38% w/w), which is in keeping with that of current Production systems endorses microalgae as a promising substrate for Bioethanol Production.
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microalgal biomass as a fermentation feedstock for Bioethanol Production
Journal of Chemical Technology & Biotechnology, 2009Co-Authors: Michael K Danquah, Razif Harun, Gareth M FordeAbstract:BACKGROUND: The increasing cost of fossil fuels as well as the escalating social and industrial awareness of the environmental impacts associated with the use of fossil fuels has created the need for more sustainable fuel options. Bioethanol, produced from renewable biomass such as sugar and starch materials, is believed to be one of these options, and it is currently being harnessed extensively. However, the utilization of sugar and starch materials as feedstocks for Bioethanol Production creates a major competition with the food market in terms of land for cultivation, and this makes Bioethanol from these sources economically less attractive. RESULT: This study explores the suitability of microalgae (Chlorococum sp.) as a substrate for Bioethanol Production via yeast (Saccharomyces bayanus) under different fermentation conditions. Results show a maximum ethanol concentration of 3.83 g L−1 obtained from 10 g L−1 of lipid-extracted microalgae debris. CONCLUSION: This productivity level (∼38% w/w), which is in keeping with that of current Production systems endorses microalgae as a promising substrate for Bioethanol Production. Copyright © 2009 Society of Chemical Industry
Michael K Danquah - One of the best experts on this subject based on the ideXlab platform.
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exploring alkaline pre treatment of microalgal biomass for Bioethanol Production
Applied Energy, 2011Co-Authors: W S Y Jason, Razif Harun, Tamara Cherrington, Michael K DanquahAbstract:We have investigated, for the first time, the alkaline pre-treatment of microalgal biomass, from the species Chlorococcum infusionum, using NaOH for Bioethanol Production. This pre-treatment step aims to release and breakdown entrapped polysaccharides in the microalgae cell walls into fermentable subunits. Three parameters were examined here; the concentration of NaOH, temperature and the pre-treatment time. The Bioethanol concentration, glucose concentration and the cell size were studied in order to determine the effectiveness of the pre-treatment process. Microscopic analysis was performed to confirm cell rupturing, the highest glucose yield was determined to be 350mg/g, and the maximum Bioethanol yield obtained was 0.26g ethanol/g algae using 0.75% (w/v) of NaOH and 120°C for 30min. Overall, the alkaline pre-treatment method proved to be promising option to pre-treat microalgal biomass for Bioethanol Production.
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influence of acid pre treatment on microalgal biomass for Bioethanol Production
Process Biochemistry, 2011Co-Authors: Razif Harun, Michael K DanquahAbstract:Abstract The utilisation of microalgal biomass as feedstock for Bioethanol Production has been very promising owing to the large amounts of carbohydrates embedded in the physiology of the microalgal cell. This is coupled with the potential of microalgae to achieve targets required for high growth rate Bioethanol Production, climate change mitigation and economic growth. The high content of complex carbohydrates entrapped in the cell wall of the microalgae makes it essential to incorporate a pre-treatment stage to release and convert these complex carbohydrates into simple sugars prior to the fermentation process. Hence, this study explores the influence of acid exposure as a microalgal pre-treatment strategy for Bioethanol Production. Different parameters were investigated: acid concentration, temperature, microalgae loading and pre-treatment time. A central composite design technique was employed to optimize the acid pre-treatment conditions. Results showed that the highest Bioethanol concentration obtained was 7.20 g/L and this was achieved when the pre-treatment step was performed with 15 g/L of microalgae at 140 °C using 1% (v/v) of sulphuric acid for 30 min. In terms of ethanol yield, ∼52 wt% (g ethanol/g microalgae) maximum was obtained using 10 g/L of microalgae and 3% (v/v) of sulphuric acid under 160 °C for 15 min. The statistical analysis revealed amongst the parameters investigated that temperature is the most critical factor during acid pre-treatment of microalgae for Bioethanol Production.
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microalgal biomass as a fermentation feedstock for Bioethanol Production
Science & Engineering Faculty, 2010Co-Authors: Razif Harun, Michael K Danquah, Gareth M FordeAbstract:Background: The increasing cost of fossil fuels as well as the escalating social and industrial awareness of the environmental impacts associated with the use of fossil fuels has created the need for more sustainable fuel options. Bioethanol, produced from renewable biomass such as sugar and starch materials, is believed to be one of these options, and it is currently being harnessed extensively. However, the utilization of sugar and starch materials as feedstocks for Bioethanol Production creates a major competition with the food market in terms of land for cultivation, and this makes Bioethanol from these sources economically less attractive. Result: This study explores the suitability of microalgae (Chlorococum sp.) as a substrate for Bioethanol Production via yeast (Saccharomycesbayanus)under different fermentation conditions. Results show a maximum ethanol concentration of 3.83 g L -1 obtained from 10 g L-1 of lipid-extracted microalgae debris. Conclusion: This productivity level (∼38% w/w), which is in keeping with that of current Production systems endorses microalgae as a promising substrate for Bioethanol Production.
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microalgal biomass as a fermentation feedstock for Bioethanol Production
Journal of Chemical Technology & Biotechnology, 2009Co-Authors: Michael K Danquah, Razif Harun, Gareth M FordeAbstract:BACKGROUND: The increasing cost of fossil fuels as well as the escalating social and industrial awareness of the environmental impacts associated with the use of fossil fuels has created the need for more sustainable fuel options. Bioethanol, produced from renewable biomass such as sugar and starch materials, is believed to be one of these options, and it is currently being harnessed extensively. However, the utilization of sugar and starch materials as feedstocks for Bioethanol Production creates a major competition with the food market in terms of land for cultivation, and this makes Bioethanol from these sources economically less attractive. RESULT: This study explores the suitability of microalgae (Chlorococum sp.) as a substrate for Bioethanol Production via yeast (Saccharomyces bayanus) under different fermentation conditions. Results show a maximum ethanol concentration of 3.83 g L−1 obtained from 10 g L−1 of lipid-extracted microalgae debris. CONCLUSION: This productivity level (∼38% w/w), which is in keeping with that of current Production systems endorses microalgae as a promising substrate for Bioethanol Production. Copyright © 2009 Society of Chemical Industry
Miguel D Ferro - One of the best experts on this subject based on the ideXlab platform.
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Bioethanol Production from steam explosion pretreated and alkali extracted cistus ladanifer rockrose
Biochemical Engineering Journal, 2015Co-Authors: Miguel D Ferro, Maria C Fernandes, Ana F C Paulino, Janis Gravitis, Dmitry V Evtuguin, Sonia O Prozil, Ana M R B XavierAbstract:Abstract Biofuels are suitable alternatives to conventional and fossil fuels that pose serious environmental adverse effects to society. Bioethanol is the most promising biofuel and can be generated from lignocellulosic biomasses. Forest residues are outside the human food chain and inexpensive raw materials, but they need a previous pretreatment, in order to improve the cellulose accessibility for further bioconversion. The study of Bioethanol Production from rockrose pretreated by steam explosion (SE) was carried out employing separate enzymatic hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) approaches. Saccharification of untreated rockrose attained only 0.9% of sugars yield. However, the steam explosion pretreatment promoted the disruption of interfibrillar surfaces of fibers with partial degradation of lignin thus enhancing the accessibility of polysaccharides toward enzymatic hydrolysis. Alkaline extraction after steam explosion pretreatment of rockrose residue (R-SE-OH) led to the partial removal of lignin, hemicelluloses, and other degradation products from fibre surface allowing an increase of 75% in the glucose yield. Bioethanol Production in SSF mode was faster and slightly more efficient process than SHF providing the best results: ethanol concentration of 16.1 g L−1, fermentation efficiency of 69.8% and a yield of 22.1 g ethanol/100 g R-SE-OH.
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enzymatic saccharification and Bioethanol Production from cynara cardunculus pretreated by steam explosion
Bioresource Technology, 2015Co-Authors: Maria C Fernandes, Miguel D Ferro, Ana F C Paulino, Joana A S Mendes, Janis Gravitis, Dmitry V Evtuguin, Ana M R B XavierAbstract:Abstract The correct choice of the specific lignocellulosic biomass pretreatment allows obtaining high biomass conversions for biorefinery implementations and cellulosic Bioethanol Production from renewable resources. Cynara cardunculus (cardoon) pretreated by steam explosion (SE) was involved in second-generation Bioethanol Production using separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) processes. Steam explosion pretreatment led to partial solubilisation of hemicelluloses and increased the accessibility of residual polysaccharides towards enzymatic hydrolysis revealing 64% of sugars yield against 11% from untreated plant material. Alkaline extraction after SE pretreatment of cardoon (CSEOH) promoted partial removal of degraded lignin, tannins, extractives and hemicelluloses thus allowing to double glucose concentration upon saccharification step. Bioethanol fermentation in SSF mode was faster than SHF process providing the best results: ethanol concentration 18.7 g L −1 , fermentation efficiency of 66.6% and a yield of 26.6 g ethanol/100 g CSEOH or 10.1 g ethanol/100 g untreated cardoon.