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Sample records for acetone butanol ethanol

  1. Assessment of in situ butanol recovery by vacuum during acetone butanol ethanol (ABE) fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butanol fermentation is product limiting due to butanol toxicity to microbial cells. Butanol (boiling point: 118 deg C) boils at a greater temperature than water (boiling point: 100 deg C) and application of vacuum technology to integrated acetone-butanol-ethanol (ABE) fermentation and recovery may ...

  2. Novel spectrophotometric method for detection and estimation of butanol in acetone-butanol-ethanol fermenter.

    PubMed

    Maiti, Sampa; Sarma, Saurabh Jyoti; Brar, Satinder Kaur; Bihan, Yann Le; Drogui, Patrick; Buelna, Gerardo; Verma, Mausam; Soccol, Carlos Ricardo

    2015-08-15

    A new, simple, rapid and selective spectrophotometric method has been developed for detection and estimation of butanol in fermentation broth. The red colored compound, produced during reduction of diquat-dibromide-monohydrate with 2-mercaptoethanol in aqueous solution at high pH (>13), becomes purple on phase transfer to butanol and gives distinct absorption at λ520nm. Estimation of butanol in the fermentation broth has been performed by salting out extraction (SOE) using saturated K3PO4 solution at high pH (>13) followed by absorbance measurement using diquat reagent. Compatibility and optimization of diquat reagent concentration for detection and estimation of butanol concentration in the fermentation broth range was verified by central composite design. A standard curve was constructed to estimate butanol in acetone-ethanol-butanol (ABE) mixture under optimized conditions. The spectrophotometric results for butanol estimation, was found to have 87.5% concordance with the data from gas chromatographic analysis.

  3. Butanol production in acetone-butanol-ethanol fermentation with in situ product recovery by adsorption.

    PubMed

    Xue, Chuang; Liu, Fangfang; Xu, Mengmeng; Tang, I-Ching; Zhao, Jingbo; Bai, Fengwu; Yang, Shang-Tian

    2016-11-01

    Activated carbon Norit ROW 0.8, zeolite CBV901, and polymeric resins Dowex Optipore L-493 and SD-2 with high specific loadings and partition coefficients were studied for n-butanol adsorption. Adsorption isotherms were found to follow Langmuir model, which can be used to estimate the amount of butanol adsorbed in acetone-butanol-ethanol (ABE) fermentation. In serum-bottle fermentation with in situ adsorption, activated carbon showed the best performance with 21.9g/L of butanol production. When operated in a fermentor, free- and immobilized-cell fermentations with adsorption produced 31.6g/L and 54.6g/L butanol with productivities of 0.30g/L·h and 0.45g/L·h, respectively. Thermal desorption produced a condensate containing ∼167g/L butanol, which resulted in a highly concentrated butanol solution of ∼640g/L after spontaneous phase separation. This in situ product recovery process with activated carbon is energy efficient and can be easily integrated with ABE fermentation for n-butanol production.

  4. Mathematical modelling of clostridial acetone-butanol-ethanol fermentation.

    PubMed

    Millat, Thomas; Winzer, Klaus

    2017-03-01

    Clostridial acetone-butanol-ethanol (ABE) fermentation features a remarkable shift in the cellular metabolic activity from acid formation, acidogenesis, to the production of industrial-relevant solvents, solventogensis. In recent decades, mathematical models have been employed to elucidate the complex interlinked regulation and conditions that determine these two distinct metabolic states and govern the transition between them. In this review, we discuss these models with a focus on the mechanisms controlling intra- and extracellular changes between acidogenesis and solventogenesis. In particular, we critically evaluate underlying model assumptions and predictions in the light of current experimental knowledge. Towards this end, we briefly introduce key ideas and assumptions applied in the discussed modelling approaches, but waive a comprehensive mathematical presentation. We distinguish between structural and dynamical models, which will be discussed in their chronological order to illustrate how new biological information facilitates the 'evolution' of mathematical models. Mathematical models and their analysis have significantly contributed to our knowledge of ABE fermentation and the underlying regulatory network which spans all levels of biological organization. However, the ties between the different levels of cellular regulation are not well understood. Furthermore, contradictory experimental and theoretical results challenge our current notion of ABE metabolic network structure. Thus, clostridial ABE fermentation still poses theoretical as well as experimental challenges which are best approached in close collaboration between modellers and experimentalists.

  5. Acetone, butanol, and ethanol production from wastewater algae.

    PubMed

    Ellis, Joshua T; Hengge, Neal N; Sims, Ronald C; Miller, Charles D

    2012-05-01

    Acetone, butanol, and ethanol (ABE) fermentation by Clostridium saccharoperbutylacetonicum N1-4 using wastewater algae biomass as a carbon source was demonstrated. Algae from the Logan City Wastewater Lagoon system grow naturally at high rates providing an abundant source of renewable algal biomass. Batch fermentations were performed with 10% algae as feedstock. Fermentation of acid/base pretreated algae produced 2.74 g/L of total ABE, as compared with 7.27 g/L from pretreated algae supplemented with 1% glucose. Additionally, 9.74 g/L of total ABE was produced when xylanase and cellulase enzymes were supplemented to the pretreated algae media. The 1% glucose supplement increased total ABE production approximately 160%, while supplementing with enzymes resulted in a 250% increase in total ABE production when compared to production from pretreated algae with no supplementation of extraneous sugar and enzymes. Additionally, supplementation of enzymes produced the highest total ABE production yield of 0.311 g/g and volumetric productivity of 0.102 g/Lh. The use of non-pretreated algae produced 0.73 g/L of total ABE. The ability to engineer novel methods to produce these high value products from an abundant and renewable feedstock such as algae could have significant implications in stimulating domestic energy economies.

  6. Evaluation of asymmetric polydimethylsiloxane-polyvinylidene fluoride composite membrane and incorporated with acetone-butanol-ethanol fermentation for butanol recovery.

    PubMed

    Xue, Chuang; Du, Guang-Qing; Chen, Li-Jie; Ren, Jian-Gang; Bai, Feng-Wu

    2014-10-20

    The polydimethylsiloxane-polyvinylidene fluoride (PDMS-PVDF) composite membrane was studied for its pervaporation performance to removal of butanol from butanol/ABE solution, fermentation broth as well as incorporated with acetone-butanol-ethanol (ABE) fermentation. The total flux and butanol titer in permeate through the PDMS-PVDF membrane were up to 769.6 g/m(2)h and 323.5 g/L at 80 °C, respectively. The butanol flux and total flux increased with increasing the feed temperature as well as the feed butanol titer. The butanol separation factor and butanol titer in permeate decreased slightly in the presence of acetone and ethanol in the feed due to their preferential dissolution and competitive permeation through the membrane. In fed-batch fermentation incorporated with pervaporation, butanol titer and flux in permeate maintained at a steady level with the range of 139.9-154.0 g/L and 13.3-16.3 g/m(2)h, respectively, which was attributed to the stable butanol titer in fermentation broth as well as the excellent hydrophobic nature of the PDMS-PVDF matrix. Therefore, the PDMS-PVDF composite membrane had a great potential in the in situ product recovery with ABE fermentation, enabling the economic production of biobutanol.

  7. Continuous acetone-butanol-ethanol fermentation using SO2-ethanol-water spent liquor from spruce.

    PubMed

    Survase, Shrikant A; Sklavounos, Evangelos; Jurgens, German; van Heiningen, Adriaan; Granström, Tom

    2011-12-01

    SO2-ethanol-water (SEW) spent liquor from spruce chips was successfully used for batch and continuous production of acetone, butanol and ethanol (ABE). Initially, batch experiments were performed using spent liquor to check the suitability for production of ABE. Maximum concentration of total ABE was found to be 8.79 g/l using 4-fold diluted SEW liquor supplemented with 35 g/l of glucose. The effect of dilution rate on solvent production, productivity and yield was studied in column reactor consisting of immobilized Clostridium acetobutylicum DSM 792 on wood pulp. Total solvent concentration of 12 g/l was obtained at a dilution rate of 0.21 h(-1). The maximum solvent productivity (4.86 g/l h) with yield of 0.27 g/g was obtained at dilution rate of 0.64 h(-1). Further, to increase the solvent yield, the unutilized sugars were subjected to batch fermentation.

  8. Pervaporation of model acetone-butanol-ethanol fermentation product solutions using polytetrafluoroethylene membranes

    SciTech Connect

    Vrana, D.L.; Meagher, M.M.; Hutkins, R.W.; Duffield, B. )

    1993-10-01

    A pervaporation apparatus was designed and tested in an effort to develop an integrated fermentation and product recovery process for acetone-butanol-ethanol(ABE) fermentation. A crossflow membrane module able to accommodate flat sheet hydrophobic membranes was used for the experiments. Permeate vapors were collected under vacuum and condensed in a dry ice/ethanol cold trap. The apparatus containing polytetrafluoroethylene membranes was tested using butanol-water and model solutions of ABE products. Parameters such as product concentration, component effect, temperature, and permeate side pressure were examined. 25 refs., 3 figs., 5 tabs.

  9. Impact of zinc supplementation on the improved fructose/xylose utilization and butanol production during acetone-butanol-ethanol fermentation.

    PubMed

    Wu, You-Duo; Xue, Chuang; Chen, Li-Jie; Bai, Feng-Wu

    2016-01-01

    Lignocellulosic biomass and dedicated energy crops such as Jerusalem artichoke are promising alternatives for biobutanol production by solventogenic clostridia. However, fermentable sugars such as fructose or xylose released from the hydrolysis of these feedstocks were subjected to the incomplete utilization by the strains, leading to relatively low butanol production and productivity. When 0.001 g/L ZnSO4·7H2O was supplemented into the medium containing fructose as sole carbon source, 12.8 g/L of butanol was achieved with butanol productivity of 0.089 g/L/h compared to only 4.5 g/L of butanol produced with butanol productivity of 0.028 g/L/h in the control without zinc supplementation. Micronutrient zinc also led to the improved butanol production up to 8.3 g/L derived from 45.2 g/L xylose as sole carbon source with increasing butanol productivity by 31.7%. Moreover, the decreased acids production was observed under the zinc supplementation condition, resulting in the increased butanol yields of 0.202 g/g-fructose and 0.184 g/g-xylose, respectively. Similar improvements were also observed with increasing butanol production by 130.2 % and 8.5 %, butanol productivity by 203.4% and 18.4%, respectively, in acetone-butanol-ethanol fermentations from sugar mixtures of fructose/glucose (4:1) and xylose/glucose (1:2) simulating the hydrolysates of Jerusalem artichoke tubers and corn stover. The results obtained from transcriptional analysis revealed that zinc may have regulatory mechanisms for the sugar transport and metabolism of Clostridium acetobutylicum L7. Therefore, micronutrient zinc supplementation could be an effective way for economic development of butanol production derived from these low-cost agricultural feedstocks.

  10. Targeted mutagenesis of the Clostridium acetobutylicum acetone-butanol-ethanol fermentation pathway.

    PubMed

    Cooksley, Clare M; Zhang, Ying; Wang, Hengzheng; Redl, Stephanie; Winzer, Klaus; Minton, Nigel P

    2012-11-01

    The production of the chemical solvents acetone and butanol by the bacterium Clostridium acetobutylicum was one of the first large-scale industrial processes to be developed, and in the first part of the last century ranked second in importance only to ethanol production. After a steep decline in its industrial use, there has been a recent resurgence of interest in the acetone-butanol-ethanol (ABE) fermentation process, with a particular emphasis on butanol production. In order to generate strains suitable for efficient use on an industrial scale, metabolic engineering is required to alter the AB ratio in favour of butanol, and eradicate the production of unwanted products of fermentation. Using ClosTron technology, a large-scale targeted mutagenesis in C. acetobutylicum ATCC 824 was carried out, generating a set of 10 mutants, defective in alcohol/aldehyde dehydrogenases 1 and 2 (adhE1, adhE2), butanol dehydrogenases A and B (bdhA, bdhB), phosphotransbutyrylase (ptb), acetate kinase (ack), acetoacetate decarboxylase (adc), CoA transferase (ctfA/ctfB), and a previously uncharacterised putative alcohol dehydrogenase (CAP0059). However, inactivation of the main hydrogenase (hydA) and thiolase (thl) could not be achieved. Constructing such a series of mutants is paramount for the acquisition of information on the mechanism of solvent production in this organism, and the subsequent development of industrial solvent producing strains. Unexpectedly, bdhA and bdhB mutants did not affect solvent production, whereas inactivation of the previously uncharacterised gene CAP0059 resulted in increased acetone, butanol, and ethanol formation. Other mutants showed predicted phenotypes, including a lack of acetone formation (adc, ctfA, and ctfB mutants), an inability to take up acids (ctfA and ctfB mutants), and a much reduced acetate formation (ack mutant). The adhE1 mutant in particular produced very little solvents, demonstrating that this gene was indeed the main contributor to

  11. Process for the fermentative production of acetone, butanol and ethanol

    DOEpatents

    Glassner, David A.; Jain, Mahendra K.; Datta, Rathin

    1991-01-01

    A process including multistage continuous fermentation followed by batch fermentation with carefully chosen temperatures for each fermentation step, combined with an asporogenic strain of C. acetobutylicum and a high carbohydrate substrate concentration yields extraordinarily high butanol and total solvents concentrations.

  12. Nesterenkonia sp. strain F, a halophilic bacterium producing acetone, butanol, and ethanol under aerobic conditions

    PubMed Central

    Amiri, Hamid; Azarbaijani, Reza; Parsa Yeganeh, Laleh; Shahzadeh Fazeli, Abolhassan; Tabatabaei, Meisam; Hosseini Salekdeh, Ghasem; Karimi, Keikhosro

    2016-01-01

    The moderately halophilic bacterium Nesterenkonia sp. strain F, which was isolated from Aran-Bidgol Lake (Iran), has the ability to produce acetone, butanol, and ethanol (ABE) as well as acetic and butyric acids under aerobic and anaerobic conditions. This result is the first report of ABE production with a wild microorganism from a family other than Clostridia and also the first halophilic species shown to produce butanol under aerobic cultivation. The cultivation of Nesterenkonia sp. strain F under anaerobic conditions with 50 g/l of glucose for 72 h resulted in the production of 105 mg/l of butanol, 122 mg/l of acetone, 0.2 g/l of acetic acid, and 2.5 g/l of butyric acid. Furthermore, the strain was cultivated on media with different glucose concentrations (20, 50, and 80 g/l) under aerobic and anaerobic conditions. Through fermentation with a 50 g/l initial glucose concentration under aerobic conditions, 66 mg/l of butanol, 125 mg/l of acetone, 291 mg/l of ethanol, 5.9 g/l of acetic acid, and 1.2 g/l of butyric acid were produced. The enzymes pertaining to the fermentation pathway in the strain were compared with the enzymes of Clostridium spp., and the metabolic pathway of fermentation used by Nesterenkonia sp. strain F was investigated. PMID:26725518

  13. Nesterenkonia sp. strain F, a halophilic bacterium producing acetone, butanol, and ethanol under aerobic conditions.

    PubMed

    Amiri, Hamid; Azarbaijani, Reza; Parsa Yeganeh, Laleh; Shahzadeh Fazeli, Abolhassan; Tabatabaei, Meisam; Salekdeh, Ghasem Hosseini; Karimi, Keikhosro

    2016-01-04

    The moderately halophilic bacterium Nesterenkonia sp. strain F, which was isolated from Aran-Bidgol Lake (Iran), has the ability to produce acetone, butanol, and ethanol (ABE) as well as acetic and butyric acids under aerobic and anaerobic conditions. This result is the first report of ABE production with a wild microorganism from a family other than Clostridia and also the first halophilic species shown to produce butanol under aerobic cultivation. The cultivation of Nesterenkonia sp. strain F under anaerobic conditions with 50 g/l of glucose for 72 h resulted in the production of 105 mg/l of butanol, 122 mg/l of acetone, 0.2 g/l of acetic acid, and 2.5 g/l of butyric acid. Furthermore, the strain was cultivated on media with different glucose concentrations (20, 50, and 80 g/l) under aerobic and anaerobic conditions. Through fermentation with a 50 g/l initial glucose concentration under aerobic conditions, 66 mg/l of butanol, 125 mg/l of acetone, 291 mg/l of ethanol, 5.9 g/l of acetic acid, and 1.2 g/l of butyric acid were produced. The enzymes pertaining to the fermentation pathway in the strain were compared with the enzymes of Clostridium spp., and the metabolic pathway of fermentation used by Nesterenkonia sp. strain F was investigated.

  14. Enhancement of n-butanol production by in situ butanol removal using permeating-heating-gas stripping in acetone-butanol-ethanol fermentation.

    PubMed

    Chen, Yong; Ren, Hengfei; Liu, Dong; Zhao, Ting; Shi, Xinchi; Cheng, Hao; Zhao, Nan; Li, Zhenjian; Li, Bingbing; Niu, Huanqing; Zhuang, Wei; Xie, Jingjing; Chen, Xiaochun; Wu, Jinglan; Ying, Hanjie

    2014-07-01

    Butanol recovery from acetone-butanol-ethanol (ABE) fed-batch fermentation using permeating-heating-gas was determined in this study. Fermentation was performed with Clostridium acetobutylicum B3 in a fibrous bed bioreactor and permeating-heating-gas stripping was used to eliminate substrate and product inhibition, which normally restrict ABE production and sugar utilization to below 20 g/L and 60 g/L, respectively. In batch fermentation (without permeating-heating-gas stripping), C. acetobutylicum B3 utilized 60 g/L glucose and produced 19.9 g/L ABE and 12 g/L butanol, while in the integrated process 290 g/L glucose was utilized and 106.27 g/L ABE and 66.09 g/L butanol were produced. The intermittent gas stripping process generated a highly concentrated condensate containing approximately 15% (w/v) butanol, 4% (w/v) acetone, a small amount of ethanol (<1%), and almost no acids, resulting in a highly concentrated butanol solution [∼ 70% (w/v)] after phase separation. Butanol removal by permeating-heating-gas stripping has potential for commercial ABE production.

  15. Effect of zinc supplementation on acetone-butanol-ethanol fermentation by Clostridium acetobutylicum.

    PubMed

    Wu, You-Duo; Xue, Chuang; Chen, Li-Jie; Bai, Feng-Wu

    2013-05-10

    In this article, effect of zinc supplementation on acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum was studied. It was found that when 0.001 g/L ZnSO4·7H2O was supplemented into the medium, solventogenesis was initiated earlier, with 21.0 g/L ABE (12.6 g/L butanol, 6.7 g/L acetone and 1.7 g/L ethanol) produced with a fermentation time of 40 h, compared to 19.4 g/L ABE (11.7 g/L butanol, 6.4 g/L acetone and 1.3g/L ethanol) produced with a fermentation time of 64 h in the control without zinc supplementation, and correspondingly ABE and butanol productivities were increased to 0.53 and 0.32 g/L/h from 0.30 and 0.18 g/L/h, increases of 76.7% and 77.8%, respectively, but their yields were not compromised. The reason for this phenomenon was attributed to rapid acids re-assimilation for more efficient ABE production, which was in accordance with relatively high pH and ORP levels maintained during the fermentation process. The maximum cell density increased by 23.8%, indicating that zinc supplementation stimulated cell growth, and consequently facilitated glucose utilization. However, more zinc supplementation exhibited an inhibitory effect, indicating that zinc supplementation at very low levels such as 0.001 g/L ZnSO4·7H2O will be an economically competitive strategy for improving butanol production.

  16. Modulation of Acetone-Butanol-Ethanol Fermentation by Carbon Monoxide and Organic Acids

    PubMed Central

    Datta, Rathin; Zeikus, J. G.

    1985-01-01

    Metabolic modulation of acetone-butanol-ethanol fermentation by Clostridium acetobutylicum with carbon monoxide (CO) and organic acids is described. CO, which is a known inhibitor of hydrogenase, was found to be effective in the concentration range of dissolved CO corresponding to a CO partial pressure of 0.1 to 0.2 atm. Metabolic modulation by CO was particularly effective when organic acids such as acetic and butyric acids were added to the fermentation as electron sinks. The uptake of organic acids was enhanced, and increases in butyric acid uptake by 50 to 200% over control were observed. Hydrogen production could be reduced by 50% and the ratio of solvents could be controlled by CO modulation and organic acid addition. Acetone production could be eliminated if desired. Butanol yield could be increased by 10 to 15%. Total solvent yield could be increased 1 to 3% and the electron efficiency to acetone-butanol-ethanol solvents could be increased from 73 to 78% for controls to 80 to 85% for CO- and organic acid-modulated fermentations. Based on these results, the dynamic nature of electron flow in this fermentation has been elucidated and mechanisms for metabolic control have been hypothesized. PMID:16346746

  17. Production of acetone, butanol, and ethanol from biomass of the green seaweed Ulva lactuca.

    PubMed

    van der Wal, Hetty; Sperber, Bram L H M; Houweling-Tan, Bwee; Bakker, Robert R C; Brandenburg, Willem; López-Contreras, Ana M

    2013-01-01

    Green seaweed Ulva lactuca harvested from the North Sea near Zeeland (The Netherlands) was characterized as feedstock for acetone, ethanol and ethanol fermentation. Solubilization of over 90% of sugars was achieved by hot-water treatment followed by hydrolysis using commercial cellulases. A hydrolysate was used for the production of acetone, butanol and ethanol (ABE) by Clostridium acetobutylicum and Clostridium beijerinckii. Hydrolysate-based media were fermentable without nutrient supplementation. C. beijerinckii utilized all sugars in the hydrolysate and produced ABE at high yields (0.35 g ABE/g sugar consumed), while C. acetobutylicum produced mostly organic acids (acetic and butyric acids). These results demonstrate the great potential of U. lactuca as feedstock for fermentation. Interestingly, in control cultures of C. beijerinckii on rhamnose and glucose, 1,2 propanediol was the main fermentation product (9.7 g/L).

  18. Acetone-butanol-ethanol production with high productivity using Clostridium acetobutylicum BKM19.

    PubMed

    Jang, Yu-Sin; Malaviya, Alok; Lee, Sang Yup

    2013-06-01

    Conventional acetone-butanol-ethanol (ABE) fermentation is severely limited by low solvent titer and productivities. Thus, this study aims at developing an improved Clostridium acetobutylicum strain possessing enhanced ABE production capability followed by process optimization for high ABE productivity. Random mutagenesis of C. acetobutylicum PJC4BK was performed by screening cells on fluoroacetate plates to isolate a mutant strain, BKM19, which exhibited the total solvent production capability 30.5% higher than the parent strain. The BKM19 produced 32.5 g L(-1) of ABE (17.6 g L(-1) butanol, 10.5 g L(-1) ethanol, and 4.4 g L(-1) acetone) from 85.2 g L(-1) glucose in batch fermentation. A high cell density continuous ABE fermentation of the BKM19 in membrane cell-recycle bioreactor was studied and optimized for improved solvent volumetric productivity. Different dilution rates were examined to find the optimal condition giving highest butanol and ABE productivities. The maximum butanol and ABE productivities of 9.6 and 20.0 g L(-1)  h(-1) , respectively, could be achieved at the dilution rate of 0.85 h(-1) . Further cell recycling experiments were carried out with controlled cell-bleeding at two different bleeding rates. The maximum solvent productivities were obtained when the fermenter was operated at a dilution rate of 0.86 h(-1) with the bleeding rate of 0.04 h(-1) . Under the optimal operational condition, butanol and ABE could be produced with the volumetric productivities of 10.7 and 21.1 g L(-1)  h(-1) , and the yields of 0.17 and 0.34 g g(-1) , respectively. The obtained butanol and ABE volumetric productivities are the highest reported productivities obtained from all known-processes.

  19. Acetone-Butanol-Ethanol (ABE) Fermentation Wastewater Treatment by Oleaginous Yeast Trichosporon cutaneum.

    PubMed

    Xiong, Lian; Huang, Chao; Li, Xiao-Mei; Chen, Xue-Fang; Wang, Bo; Wang, Can; Zeng, Xin-An; Chen, Xin-De

    2015-05-01

    In the present study, acetone-butanol-ethanol (ABE) fermentation wastewater with high chemical oxygen demand (COD) value (about 18,000 mg/L) was biologically treated by oleaginous yeast Trichosporon cutaneum without any pretreatment. During fermentation, most COD degradation was finished within 48 h and finally, a maximum COD degradation of 68% was obtained. The highest biomass and lipid content was 4.9 g/L and 14.7%, respectively. Various materials including sugars (glucose and xylose), organic acids (acetic acid and butyric acid), and alcohol compounds (ethanol and butanol) could be utilized as carbon sources by T. cutaneum simultaneously; thus, it has a broad carbon source spectrum and is a potential microorganism for biological treatment for various wastewaters. Overall, the lipid composition of microbial oils produced by this bioconversion is similar to that of vegetable oils, and thus, it could be used for biodiesel production.

  20. Organosolv pretreatment of rice straw for efficient acetone, butanol, and ethanol production.

    PubMed

    Amiri, Hamid; Karimi, Keikhosro; Zilouei, Hamid

    2014-01-01

    Acetone-butanol-ethanol (ABE) was produced from rice straw using a process containing ethanol organosolv pretreatment, enzymatic hydrolysis, and fermentation by Clostridium acetobutylicum bacterium. Pretreatment of the straw with 75% (v/v) aqueous ethanol containing 1% w/w sulfuric acid at 150 °C for 60 min resulted in the highest total sugar concentration of 31 g/L in the enzymatic hydrolysis. However, the highest ABE concentration and productivity (10.5 g/L and 0.20 g/Lh, respectively) were obtained from the straw pretreated at 180 °C for 30 min. Enzymatic hydrolysis of the straw pretreated at 180 °C for 30 min with 5% solid loading resulted in glucose yield of 46.2%, which was then fermented to 80.3 g butanol, 21.1 g acetone, and 22.5 g ethanol, the highest overall yield of ABE production. Thus, the organosolv pretreatment can be applied for efficient production of the solvents from rice straw.

  1. The enhancement of butanol production by in situ butanol removal using biodiesel extraction in the fermentation of ABE (acetone-butanol-ethanol).

    PubMed

    Yen, Hong-Wei; Wang, Yi-Cheng

    2013-10-01

    High butanol accumulation is due to feedback inhibition which leads to the low butanol productivity observed in acetone-butanol-ethanol (ABE) fermentation. The aim of this study is to use biodiesel as an extractant for the in situ removal of butanol from the broth. The results indicate that adding biodiesel as an extractant at the beginning of fermentation significantly enhances butanol production. No significant toxicity of biodiesel on the growth of Clostridium acetobutylicum is observed. In the fed-batch operation with glucose feeding, the maximum total butanol obtained is 31.44 g/L, as compared to the control batch (without the addition of biodiesel) at 9.85 g/L. Moreover, the productivity obtained is 0.295 g/L h in the fed-batch, which is higher than that of 0.185 g/L h for the control batch. The in situ butanol removal by the addition of biodiesel has great potential for commercial ABE production.

  2. Microbial inhibitors: formation and effects on acetone-butanol-ethanol fermentation of lignocellulosic biomass.

    PubMed

    Baral, Nawa Raj; Shah, Ajay

    2014-11-01

    Biobutanol is a promising biofuel due to the close resemblance of its fuel properties to gasoline, and it is produced via acetone-butanol-ethanol (ABE) fermentation using Clostridium species. However, lignin in the crystalline structure of the lignin-cellulose-hemicellulose biomass complex is not readily consumed by the Clostridium; thus, pretreatment is required to degrade this complex. During pretreatment, some fractions of cellulose and hemicellulose are converted into fermentable sugars, which are further converted to ABE. However, a major setback resulting from common pretreatment processes is the formation of sugar and lignin degradation compounds, including weak acids, furan derivatives, and phenolic compounds, which have inhibitory effects on the Clostridium. In addition, butanol concentration above 13 g/L in the fermentation broth is itself toxic to most Clostridium strain(s). This review summarizes the current state-of-the-art knowledge on the formation of microbial inhibitors during the most common lignocellulosic biomass pretreatment processes. Metabolic effects of inhibitors and their impacts on ABE production, as well as potential solutions for reducing inhibitor formation, such as optimizing pretreatment process parameters, using inhibitor tolerant strain(s) with high butanol yield ability, continuously recovering butanol during ABE fermentation, and adopting consolidated bioprocessing, are also discussed.

  3. Kinetic modeling and sensitivity analysis of acetone-butanol-ethanol production.

    PubMed

    Shinto, Hideaki; Tashiro, Yukihiro; Yamashita, Mayu; Kobayashi, Genta; Sekiguchi, Tatsuya; Hanai, Taizo; Kuriya, Yuki; Okamoto, Masahiro; Sonomoto, Kenji

    2007-08-01

    A kinetic simulation model of metabolic pathways that describes the dynamic behaviors of metabolites in acetone-butanol-ethanol (ABE) production by Clostridium saccharoperbutylacetonicum N1-4 was proposed using a novel simulator WinBEST-KIT. This model was validated by comparing with experimental time-course data of metabolites in batch cultures over a wide range of initial glucose concentrations (36.1-295 mM). By introducing substrate inhibition, product inhibition of butanol, activation of butyrate and considering the cessation of metabolic reactions in the case of insufficiency of energy after glucose exhaustion, the revised model showed 0.901 of squared correlation coefficient (r(2)) between experimental time-course of metabolites and calculated ones. Thus, the final revised model is assumed to be one of the best candidates for kinetic simulation describing dynamic behavior of metabolites in ABE production. Sensitivity analysis revealed that 5% increase in reaction of reverse pathway of butyrate production (R(17)) and 5% decrease in reaction of CoA transferase for butyrate (R(15)) highly contribute to high production of butanol. These system analyses should be effective in the elucidation which pathway is metabolic bottleneck for high production of butanol.

  4. Recent progress on industrial fermentative production of acetone-butanol-ethanol by Clostridium acetobutylicum in China.

    PubMed

    Ni, Ye; Sun, Zhihao

    2009-06-01

    China is one of the few countries, which maintained the fermentative acetone-butanol-ethanol (ABE) production for several decades. Until the end of the last century, the ABE fermentation from grain was operated in a few industrial scale plants. Due to the strong competition from the petrochemical industries, the fermentative ABE production lost its position in the 1990s, when all the solvent fermentation plants in China were closed. Under the current circumstances of concern about energy limitations and environmental pollution, new opportunities have emerged for the traditional ABE fermentation industry since it could again be potentially competitive with chemical synthesis. From 2006, several ABE fermentation plants in China have resumed production. The total solvent (acetone, butanol, and ethanol) production capacity from ten plants reached 210,000 tons, and the total solvent production is expected to be extended to 1,000,000 tons (based on the available data as of Sept. 2008). This article reviews current work in strain development, the continuous fermentation process, solvent recovery, and economic evaluation of ABE process in China. Challenges for an economically competitive ABE process in the future are also discussed.

  5. Optimization of wastewater microalgae saccharification using dilute acid hydrolysis for acetone, butanol, and ethanol fermentation

    SciTech Connect

    Castro, Yessica; Ellis, Joshua T.; Miller, Charles D.; Sims, Ronald C.

    2015-02-01

    Exploring and developing sustainable and efficient technologies for biofuel production are crucial for averting global consequences associated with fuel shortages and climate change. Optimization of sugar liberation from wastewater algae through acid hydrolysis was determined for subsequent fermentation to acetone, butanol, and ethanol (ABE) by Clostridium saccharoperbutylacetonicum N1-4. Acid concentration, retention time, and temperature were evaluated to determine optimal hydrolysis conditions by assessing the sugar and ABE yield as well as the associated costs. Sulfuric acid concentrations ranging from 0-1.5 M, retention times of 40-120 min, and temperatures from 23°C- 90°C were combined to form a full factorial experiment. Acid hydrolysis pretreatment of 10% dried wastewater microalgae using 1.0 M sulfuric acid for 120 min at 80-90°C was found to be the optimal parameters, with a sugar yield of 166.1 g for kg of dry algae, concentrations of 5.23 g/L of total ABE, and 3.74 g/L of butanol at a rate of USD $12.83 per kg of butanol.

  6. In situ hydrogen, acetone, butanol, ethanol and microdiesel production by Clostridium acetobutylicum ATCC 824 from oleaginous fungal biomass.

    PubMed

    Hassan, Elhagag Ahmed; Abd-Alla, Mohamed Hemida; Bagy, Magdy Mohamed Khalil; Morsy, Fatthy Mohamed

    2015-08-01

    An in situ batch fermentation technique was employed for biohydrogen, acetone, butanol, ethanol and microdiesel production from oleaginous fungal biomass using the anaerobic fermentative bacterium Clostridium acetobutylicum ATCC 824. Oleaginous fungal Cunninghamella echinulata biomass which has ability to accumulate up to 71% cellular lipid was used as the substrate carbon source. The maximum cumulative hydrogen by C. acetobutylicum ATCC 824 from crude C. echinulata biomass was 260 ml H2 l(-1), hydrogen production efficiency was 0.32 mol H2 mole(-1) glucose and the hydrogen production rate was 5.2 ml H2 h(-1). Subsequently, the produced acids (acetic and butyric acids) during acidogenesis phase are re-utilized by ABE-producing clostridia and converted into acetone, butanol, and ethanol. The total ABE produced by C. acetobutylicum ATCC 824 during batch fermentation was 3.6 g l(-1) from crude fungal biomass including acetone (1.05 g l(-1)), butanol (2.19 g l(-1)) and ethanol (0.36 g l(-1)). C. acetobutylicum ATCC 824 has ability to produce lipolytic enzymes with a specific activity 5.59 U/mg protein to hydrolyze ester containing substrates. The lipolytic potential of C. acetobutylicum ATCC 824 was used as a biocatalyst for a lipase transesterification process using the produced ethanol from ABE fermentation for microdiesel production. The fatty acid ethyl esters (microdiesel) generated from the lipase transesterification of crude C. echinulata dry mass was analyzed by GC/MS as 15.4% of total FAEEs. The gross energy content of biohydrogen, acetone, butanol, ethanol and biodiesel generated through C. acetobutylicum fermentation from crude C. echinulata dry mass was 3113.14 kJ mol(-1). These results suggest a possibility of integrating biohydrogen, acetone, butanol and ethanol production technology by C. acetobutylicum with microdiesel production from crude C. echinulata dry mass and therefore improve the feasibility and commercialization of bioenergy production.

  7. Continuous acetone-butanol-ethanol production by corn stalk immobilized cells.

    PubMed

    Zhang, Yuedong; Ma, Yujiu; Yang, Fangxiao; Zhang, Chunhui

    2009-08-01

    Corn stalk was used as a support to immobilize Clostridia beijerinckii ATCC 55025 in the fermentation process of acetone, butanol, and ethanol production. The effect of the dilution rate on solvent production was examined in a steady-state 20-day continuous flow operation. The maximum total solvent concentration of 8.99 g l(-1) was obtained at a dilution rate of 0.2 h(-1). Increasing the dilution rate between 0.2 and 1.0 h(-1) resulted in an increased solvent productivity, and the highest solvent productivity was obtained at 5.06 g l(-1) h(-1) with a dilution rate of 1 h(-1). The maximum solvent yield from glucose of 0.32 g g(-1) was observed at 0.25 h(-1). The cell adsorption and morphology change during the growth on corn stalk support were examined by the SEM.

  8. Kinetic Study of Acetone-Butanol-Ethanol Fermentation in Continuous Culture

    PubMed Central

    Buehler, Edward A.; Mesbah, Ali

    2016-01-01

    Acetone-butanol-ethanol (ABE) fermentation by clostridia has shown promise for industrial-scale production of biobutanol. However, the continuous ABE fermentation suffers from low product yield, titer, and productivity. Systems analysis of the continuous ABE fermentation will offer insights into its metabolic pathway as well as into optimal fermentation design and operation. For the ABE fermentation in continuous Clostridium acetobutylicum culture, this paper presents a kinetic model that includes the effects of key metabolic intermediates and enzymes as well as culture pH, product inhibition, and glucose inhibition. The kinetic model is used for elucidating the behavior of the ABE fermentation under the conditions that are most relevant to continuous cultures. To this end, dynamic sensitivity analysis is performed to systematically investigate the effects of culture conditions, reaction kinetics, and enzymes on the dynamics of the ABE production pathway. The analysis provides guidance for future metabolic engineering and fermentation optimization studies. PMID:27486663

  9. Acetone-butanol-ethanol (ABE) fermentation in an immobilized cell trickle bed reactor.

    PubMed

    Park, C H; Okos, M R; Wankat, P C

    1989-06-05

    Acetone-butanol-ethanol (ABE) fermentation was successfully carried out in an immobilized cell trickle bed reactor. The reactor was composed of two serial columns packed with Clostridium acetobutylicum ATCC 824 entrapped on the surface of natural sponge segments at a cell loading in the range of 2.03-5.56 g dry cells/g sponge. The average cell loading was 3.58 g dry cells/g sponge. Batch experiments indicated that a critical pH above 4.2 is necessary for the initiation of cell growth. One of the media used during continuous experiments consisted of a salt mixture alone and the other a nutrient medium containing a salt mixture with yeast extract and peptone. Effluent pH was controlled by supplying various fractions of the two different types of media. A nutrient medium fraction above 0.6 was crucial for successful fermentation in a trickle bed reactor. The nutrient medium fraction is the ratio of the volume of the nutrient medium to the total volume of nutrient plus salt medium. Supplying nutrient medium to both columns continuously was an effective way to meet both pH and nutrient requirement. A 257-mL reactor could ferment 45 g/L glucose from an initial concentration of 60 g/L glucose at a rate of 70 mL/h. Butanol, acetone, and ethanol concentrations were 8.82, 5.22, and 1.45 g/L, respectively, with a butanol and total solvent yield of 19.4 and 34.1 wt %. Solvent productivity in an immobilized cell trickle bed reactor was 4.2 g/L h, which was 10 times higher than that obtained in a batch fermentation using free cells and 2.76 times higher than that of an immobilized CSTR. If the nutrient medium fraction was below 0.6 and the pH was below 4.2, the system degenerated. Oxygen also contributed to the system degeneration. Upon degeneration, glucose consumption and solvent yield decreased to 30.9 g/L and 23.0 wt %, respectively. The yield of total liquid product (40.0 wt %) and butanol selectivity (60.0 wt %) remained almost constant. Once the cells were degenerated

  10. Acetone-butanol-ethanol production from substandard and surplus dates by Egyptian native Clostridium strains.

    PubMed

    Abd-Alla, Mohamed Hemida; Zohri, Abdel-Naser Ahmed; El-Enany, Abdel-Wahab Elsadek; Ali, Shimaa Mohamed

    2015-04-01

    One hundred and seven mesophilic isolates of Clostridium were isolated from agricultural soils cultivated with different plants in Assuit Governorate, Egypt. Eighty isolates (out of 107) showed the ability to produce ABE (Acetone, butanol and ethanol) on T6 medium ranging from 0.036 to 31.89 g/L. The highest numbers of ABE producing isolates were obtained from soil samples of potato contributing 27 isolates, followed by 18 isolates from wheat and 10 isolates from onion. On the other hand, there were three native isolates that produced ABE more than those produced by the reference isolate Clostridium acetobutylicum ATCC 824 (11.543 g/L). The three isolates were identified based on phenotypic and gene encoding 16S rRNA as Clostridium beijerinckii ASU10 (KF372577), Clostridium chauvoei ASU55 (KF372580) and Clostridium roseum ASU58 (KF372581). The highest ABE level from substandard and surplus dates was produced by C. beijerinckii ASU10 (24.07 g/L) comprising butanol 67.15% (16.16 g/L), acetone 30.73% (7.4 g/L) and ethanol 2.12% (0.51 g/L), while C. roseum ASU58 and C. chauvoei ASU55 produced ABE contributing 20.20 and 13.79 g/L, respectively. ABE production by C. acetobutylicum ATCC 824 was 15.01 g/L. This study proved that the native strains C. beijerinckii ASU10 and C. roseum ASU58 have high competitive efficacy on ABE production from economical substrate as substandard and surplus date fruits. Additionally, using this substrate without any nutritional components is considered to be a commercial substrate for desired ABE production.

  11. A novel in situ gas stripping-pervaporation process integrated with acetone-butanol-ethanol fermentation for hyper n-butanol production.

    PubMed

    Xue, Chuang; Liu, Fangfang; Xu, Mengmeng; Zhao, Jingbo; Chen, Lijie; Ren, Jiangang; Bai, Fengwu; Yang, Shang-Tian

    2016-01-01

    Butanol is considered as an advanced biofuel, the development of which is restricted by the intensive energy consumption of product recovery. A novel two-stage gas stripping-pervaporation process integrated with acetone-butanol-ethanol (ABE) fermentation was developed for butanol recovery, with gas stripping as the first-stage and pervaporation as the second-stage using the carbon nanotubes (CNTs) filled polydimethylsiloxane (PDMS) mixed matrix membrane (MMM). Compared to batch fermentation without butanol recovery, more ABE (27.5 g/L acetone, 75.5 g/L butanol, 7.0 g/L ethanol vs. 7.9 g/L acetone, 16.2 g/L butanol, 1.4 g/L ethanol) were produced in the fed-batch fermentation, with a higher butanol productivity (0.34 g/L · h vs. 0.30 g/L · h) due to reduced butanol inhibition by butanol recovery. The first-stage gas stripping produced a condensate containing 155.6 g/L butanol (199.9 g/L ABE), which after phase separation formed an organic phase containing 610.8 g/L butanol (656.1 g/L ABE) and an aqueous phase containing 85.6 g/L butanol (129.7 g/L ABE). Fed with the aqueous phase of the condensate from first-stage gas stripping, the second-stage pervaporation using the CNTs-PDMS MMM produced a condensate containing 441.7 g/L butanol (593.2 g/L ABE), which after mixing with the organic phase from gas stripping gave a highly concentrated product containing 521.3 g/L butanol (622.9 g/L ABE). The outstanding performance of CNTs-PDMS MMM can be attributed to the hydrophobic CNTs giving an alternative route for mass transport through the inner tubes or along the smooth surface of CNTs. This gas stripping-pervaporation process with less contaminated risk is thus effective in increasing butanol production and reducing energy consumption.

  12. Acetone-butanol-ethanol production from corn stover pretreated by alkaline twin-screw extrusion pretreatment.

    PubMed

    Zhang, Yuedong; Hou, Tongang; Li, Bin; Liu, Chao; Mu, Xindong; Wang, Haisong

    2014-05-01

    In this study, the alkaline twin-screw extrusion pretreated corn stover was subjected to enzymatic hydrolysis after washing. The impact of solid loading and enzyme dose on enzymatic hydrolysis was investigated. It was found that 68.2 g/L of total fermentable sugar could be obtained after enzymatic hydrolysis with the solid loading of 10 %, while the highest sugar recovery of 91.07 % was achieved when the solid loading was 2 % with the cellulase dose of 24 FPU/g substrate. Subsequently, the hydrolyzate was fermented by Clostridium acetobutylicum ATCC 824. The acetone-butanol-ethanol (ABE) production of the hydrolyzate was compared with the glucose, xylose and simulated hydrolyzate medium which have the same reducing sugar concentration. It was shown that 7.1 g/L butanol and 11.2 g/L ABE could be produced after 72 h fermentation for the hydrolyzate obtained from enzymatic hydrolysis with 6 % solid loading. This is comparable to the glucose and simulated hydrozate medium, and the overall ABE yield could reach 0.112 g/g raw corn stover.

  13. Acetone-butanol-ethanol production from Kraft paper mill sludge by simultaneous saccharification and fermentation.

    PubMed

    Guan, Wenjian; Shi, Suan; Tu, Maobing; Lee, Yoon Y

    2016-01-01

    Paper mill sludge (PS), a solid waste from pulp and paper industry, was investigated as a feedstock for acetone-butanol-ethanol (ABE) production by simultaneous saccharification and fermentation (SSF). ABE fermentation of paper sludge by Clostridium acetobutylicum required partial removal of ash in PS to enhance its enzymatic digestibility. Enzymatic hydrolysis was found to be a rate-limiting step in the SSF. A total of 16.4-18.0g/L of ABE solvents were produced in the SSF of de-ashed PS with solid loading of 6.3-7.4% and enzyme loading of 10-15FPU/g-glucan, and the final solvent yield reached 0.27g/g sugars. No pretreatment and pH control were needed in ABE fermentation of paper sludge, which makes it an attractive feedstock for butanol production. The results suggested utilization of paper sludge should not only consider the benefits of buffering effect of CaCO3 in fermentation, but also take into account its inhibitory effect on enzymatic hydrolysis.

  14. Recovery of dilute aqueous acetone, butanol, and ethanol with immobilized calixarene cavities.

    PubMed

    Thompson, Anthony B; Scholes, Rachel C; Notestein, Justin M

    2014-01-08

    Macrocyclic calixarene molecules were modified with functional groups of different polarities at the upper rim and subsequently grafted to mesoporous silica supports through a single Si atom linker. The resulting materials were characterized by thermogravimetric analysis, UV-visible spectroscopy, nitrogen physisorption, and solid-state NMR spectroscopy. Materials were then used to separate acetone, n-butanol, and ethanol from dilute aqueous solution, as may be useful in the recovery of fermentation-based biofuels. For the purpose of modeling batch adsorption isotherms, the materials were considered to have one strong adsorption site per calixarene molecule and a larger number of weak adsorption sites on the silica surface and external to the calixarene cavity. The magnitude of the net free energy change of adsorption varied from approximately 15 to 20 kJ/mol and was found to decrease as upper-rim calixarene functional groups became more electron-withdrawing. Adsorption appears to be driven by weak van der Waals interactions with the calixarene cavity and, particularly for butanol, minimizing contacts with solvent water. In addition to demonstrating potentially useful new sorbents, these materials provide some of the first experimental estimates of the energy of interaction between aqueous solutes and hydrophobic calixarenes, which have previously been inaccessible because of the insolubility of most nonionic calixarene species in water.

  15. Efficient acetone-butanol-ethanol production by Clostridium beijerinckii from sugar beet pulp.

    PubMed

    Bellido, Carolina; Infante, Celia; Coca, Mónica; González-Benito, Gerardo; Lucas, Susana; García-Cubero, María Teresa

    2015-08-01

    Sugar beet pulp (SBP) has been investigated as a promising feedstock for ABE fermentation by Clostridium beijerinckii. Although lignin content in SBP is low, a pretreatment is needed to enhance enzymatic hydrolysis and fermentation yields. Autohydrolysis at pH 4 has been selected as the best pretreatment for SBP in terms of sugars release and acetone and butanol production. The best overall sugars release yields from raw SBP ranged from 66.2% to 70.6% for this pretreatment. The highest ABE yield achieved was 0.4g/g (5.1g/L of acetone and 6.6g/L butanol) and 143.2g ABE/kg SBP (62.3g acetone and 80.9g butanol) were obtained when pretreated SBP was enzymatically hydrolyzed at 7.5% (w/w) solid loading. Higher solid loadings (10%) offered higher acetone and butanol titers (5.8g/L of acetone and 7.8g/L butanol). All the experiments were carried out under not-controlling pH conditions reaching about 5.3 in the final samples.

  16. Genome analysis of a hyper acetone-butanol-ethanol (ABE) producing Clostridium acetobutylicum BKM19.

    PubMed

    Cho, Changhee; Choe, Donghui; Jang, Yu-Sin; Kim, Kyung-Jin; Kim, Won Jun; Cho, Byung-Kwan; Papoutsakis, E Terry; Bennett, George N; Seung, Do Young; Lee, Sang Yup

    2017-02-01

    Previously the development of a hyper acetone-butanol-ethanol (ABE) producing Clostridium acetobutylicum BKM19 strain capable of producing 30.5% more total solvent by random mutagenesis of its parental strain PJC4BK, which is a buk mutant C. acetobutylicum ATCC 824 strain is reported. Here, BKM19 and PJC4BK strains are re-sequenced by a high-throughput sequencing technique to understand the mutations responsible for enhanced solvent production. In comparison with the C. acetobutylicum PJC4BK, 13 single nucleotide variants (SNVs), one deletion and one back mutation SNV are identified in the C. acetobutylicum BKM19 genome. Except for one SNV found in the megaplasmid, all mutations are found in the chromosome of BKM19. Among them, a mutation in the thlA gene encoding thiolase is further studied with respect to enzyme activity and butanol production. The mutant thiolase (thlA(V5A) ) is showed a 32% higher activity than that of the wild-type thiolase (thlA(WT) ). In batch fermentation, butanol production is increased by 26% and 23% when the thlA(V5A) gene is overexpressed in the wild-type C. acetobutylicum ATCC 824 and in its derivative, the thlA-knockdown TKW-A strain, respectively. Based on structural analysis, the mutation in thiolase does not have a direct effect on the regulatory determinant region (RDR). However, the mutation at the 5(th) residue seems to influence the stability of the RDR, and thus, increases the enzymatic activity and enhances solvent production in the BKM19 strain.

  17. Improvement of acetone, butanol, and ethanol production from woody biomass using organosolv pretreatment.

    PubMed

    Amiri, Hamid; Karimi, Keikhosro

    2015-10-01

    A suitable pretreatment is a prerequisite of efficient acetone-butanol-ethanol (ABE) production from wood by Clostridia. In this study, organosolv fractionation, an effective pretreatment with ability to separate lignin as a co-product, was evaluated for ABE production from softwood pine and hardwood elm. ABE production from untreated woods was limited to the yield of 81 g ABE/kg wood and concentration of 5.5 g ABE/L. Thus, the woods were pretreated with aqueous ethanol at elevated temperatures before hydrolysis and fermentation to ABE by Clostridium acetobutylicum. Hydrolysis of pine and elm pretreated at 180 °C for 60 min resulted in the highest sugar concentrations of 16.8 and 23.2 g/L, respectively. The hydrolysate obtained from elm was fermented to ABE with the highest yield of 121.1 g/kg and concentration of 11.6 g/L. The maximum yield of 87.9 g/kg was obtained from pine pretreated for 30 min at 150 °C. Moreover, structural modifications in the woods were investigated and related to the improvements. The woody biomasses are suitable feedstocks for ABE production after the organosolv pretreatment. Effects of the pretreatment conditions on ABE production might be related to the reduced cellulose crystallinity, reduced lignin and hemicellulose content, and lower total phenolic compounds in the hydrolysates.

  18. High acetone-butanol-ethanol production in pH-stat co-feeding of acetate and glucose.

    PubMed

    Gao, Ming; Tashiro, Yukihiro; Wang, Qunhui; Sakai, Kenji; Sonomoto, Kenji

    2016-08-01

    We previously reported the metabolic analysis of butanol and acetone production from exogenous acetate by (13)C tracer experiments (Gao et al., RSC Adv., 5, 8486-8495, 2015). To clarify the influence of acetate on acetone-butanol-ethanol (ABE) production, we first performed an enzyme assay in Clostridium saccharoperbutylacetonicum N1-4. Acetate addition was found to drastically increase the activities of key enzymes involved in the acetate uptake (phosphate acetyltransferase and CoA transferase), acetone formation (acetoacetate decarboxylase), and butanol formation (butanol dehydrogenase) pathways. Subsequently, supplementation of acetate during acidogenesis and early solventogenesis resulted in a significant increase in ABE production. To establish an efficient ABE production system using acetate as a co-substrate, several shot strategies were investigated in batch culture. Batch cultures with two substrate shots without pH control produced 14.20 g/L butanol and 23.27 g/L ABE with a maximum specific butanol production rate of 0.26 g/(g h). Furthermore, pH-controlled (at pH 5.5) batch cultures with two substrate shots resulted in not only improved acetate consumption but also a further increase in ABE production. Finally, we obtained 15.13 g/L butanol and 24.37 g/L ABE at the high specific butanol production rate of 0.34 g/(g h) using pH-stat co-feeding method. Thus, in this study, we established a high ABE production system using glucose and acetate as co-substrates in a pH-stat co-feeding system with C. saccharoperbutylacetonicum N1-4.

  19. Impact of sweet sorghum cuticular waxes (SSCW) on acetone-butanol-ethanol fermentation using Clostridium acetobutylicum ABE1201.

    PubMed

    Cai, Di; Chang, Zhen; Wang, Chengyu; Ren, Wenqiang; Wang, Zheng; Qin, Peiyong; Tan, Tianwei

    2013-12-01

    The effect of cuticular waxes of sweet sorghum stem on acetone-butanol-ethanol (ABE) fermentation process was investigated. About 22.9% of butanol and 25.4% of ABE were decreased with fermentation period extended when SSCW was added. The inhibition of SSCW militate against both acidogenesis and solventogenesis phase, which were inconsistent with the inhibition of lignocellulose hydrolysate. Further studies on the composition of SSCW were performed. Regulations of inhibition with different carbon chain length of main compositions of SSCW on ABE fermentation were also investigated.

  20. History of the acetone-butanol-ethanol fermentation industry in China: development of continuous production technology.

    PubMed

    Chiao, Jui-shen; Sun, Zhi-hao

    2007-01-01

    The acetone-butanol-ethanol (ABE) fermentation industry in China was started in the early 1950s in Shanghai and expanded rapidly thereafter. At its peak, there were about 30 plants all over the country and the total annual production of solvents reached 170,000 tons. This large enterprise was compelled to complete shutdown at the end of the 20th century due to the rapid increase of petrochemicals. The success of the ABE industry in China had special features like the development of a continuous fermentation technology. Its main strategic considerations were as follows: maintaining maximal growth and acid production phase, adoption of multiple stages in the solvent phase to allow gradual adaptation to increasing solvent, and the incorporation of stillage to offer enough nutrients to delay cell degeneration. Due to the tremendous national demand for solvents, China has begun a new round of ABE fermentation research. It is expected that a new era in the ABE industry is on the horizon.

  1. Integrated, systems metabolic picture of acetone-butanol-ethanol fermentation by Clostridium acetobutylicum.

    PubMed

    Liao, Chen; Seo, Seung-Oh; Celik, Venhar; Liu, Huaiwei; Kong, Wentao; Wang, Yi; Blaschek, Hans; Jin, Yong-Su; Lu, Ting

    2015-07-07

    Microbial metabolism involves complex, system-level processes implemented via the orchestration of metabolic reactions, gene regulation, and environmental cues. One canonical example of such processes is acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum, during which cells convert carbon sources to organic acids that are later reassimilated to produce solvents as a strategy for cellular survival. The complexity and systems nature of the process have been largely underappreciated, rendering challenges in understanding and optimizing solvent production. Here, we present a system-level computational framework for ABE fermentation that combines metabolic reactions, gene regulation, and environmental cues. We developed the framework by decomposing the entire system into three modules, building each module separately, and then assembling them back into an integrated system. During the model construction, a bottom-up approach was used to link molecular events at the single-cell level into the events at the population level. The integrated model was able to successfully reproduce ABE fermentations of the WT C. acetobutylicum (ATCC 824), as well as its mutants, using data obtained from our own experiments and from literature. Furthermore, the model confers successful predictions of the fermentations with various network perturbations across metabolic, genetic, and environmental aspects. From foundation to applications, the framework advances our understanding of complex clostridial metabolism and physiology and also facilitates the development of systems engineering strategies for the production of advanced biofuels.

  2. Effects of nutritional enrichment on the production of acetone-butanol-ethanol (ABE) by Clostridium acetobutylicum.

    PubMed

    Choi, Sung Jun; Lee, Joungmin; Jang, Yu-Sin; Park, Jin Hwan; Lee, Sang Yup; Kim, In Ho

    2012-12-01

    Clostridium acetobutylicum is an industrially important organism that produces acetone-butanol-ethanol (ABE). The main objective of this study was to characterize the effects of increased cell density on the production of ABE during the phase transition from acidogenesis to solventogenesis in C. acetobutylicum. The increased ABE productivity of C. acetobutylicum was obtained by increasing the cell density using a newly designed medium (designated C. a cetobutylicum medium 1; CAM1). The maximum OD(600) value of C. acetobutylicum ATCC 824 strain obtained with CAM1 was 19.7, which is 1.8 times higher than that obtained with clostridial growth medium (CGM). The overall ABE productivity obtained in the CAM1-fermetation of the ATCC 824 strain was 0.83 g/L/h, which is 1.5 times higher than that (0.55 g/L/h) obtained with CGM. However, the increased productivity obtained with CAM1 did not result in an increase in the final ABE titer, because phase transition occurred at a high titer of acids.

  3. Acetone-butanol-ethanol production in a novel continuous flow system.

    PubMed

    Elbeshbishy, Elsayed; Dhar, Bipro Ranjan; Hafez, Hisham; Lee, Hyung-Sool

    2015-08-01

    This study investigates the potential of using a novel integrated biohydrogen reactor clarifier system (IBRCS) for acetone-butanol-ethanol (ABE) production using a mixed culture at different organic loading rates (OLRs). The results of this study showed that using a setting tank after the fermenter and recycle the settled biomass to the fermenter is a practical option to achieve high biomass concentration in the fermenter and thus sustainable ABE fermentation in continuous mode. The average ABE concentrations of 2.3, 7.0, and 14.6gABE/L which were corresponding to ABE production rates of 0.4, 1.4, and 2.8gABE/Lreactorh were achieved at OLRs of 21, 64, and 128gCOD/Lreactord, respectively. The main volatile fatty acids components in the effluent were acetic, propionic, and butyric acids. Acetic acid was the predominant component in the OLR-1, while butyric acid was the predominant acid in OLRs 2 and 3.

  4. Electrooptical measurements for monitoring metabolite fluxes in acetone-butanol-ethanol fermentations.

    PubMed

    Junne, Stefan; Klein, Eva; Angersbach, Alexander; Goetz, Peter

    2008-03-01

    Anisotropy of electrical polarizability in Clostridium acetobutylicum cells during pH 5 controlled acetone butanol ethanol fermentations was observed. Cell length was determined from the electrooptical data. Mean length was determined as being 2.5 microm in the growth phase and 3.5 microm in the early stationary phase. Based on the obtained frequency dispersion of polarizability anisotropy (FDPA) in the range of 190 to 2,100 kHz, the switch from the acidogenic to the solventogenic phase could be monitored. The slope of polarizability versus the frequency made it possible to differentiate between phases of dominating acid and solvent production. Metabolite fluxes determined from concentration measurements correlated well to the polarizability. A partial least-squares (PLS) model was established and validated by applying data from several fermentations. The root mean square error of calibration (RMSEC) was 0.09 for the acid fluxes and 0.11 for the solvent fluxes. The root mean square error of prediction (RMSEP) was 0.20 for acid fluxes and 0.24 for solvent fluxes. The ratio of polarizability at high and low frequencies correlated to the ongoing sporulation process. At ratios below 0.25, spore formation in the cells became visible under the microscope. The advantage of using electrooptical measurements is the ability to observe metabolite fluxes rather than concentrations, which provides useful information on productivity during a bioprocess.

  5. Production of an acetone-butanol-ethanol mixture from Clostridium acetobutylicum and its conversion to high-value biofuels.

    PubMed

    Sreekumar, Sanil; Baer, Zachary C; Pazhamalai, Anbarasan; Gunbas, Gorkem; Grippo, Adam; Blanch, Harvey W; Clark, Douglas S; Toste, F Dean

    2015-03-01

    Clostridium acetobutylicum is a bacterial species that ferments sugar to a mixture of organic solvents (acetone, butanol and ethanol). This protocol delineates a methodology to combine solventogenic clostridial fermentation and chemical catalysis via extractive fermentation for the production of biofuel blendstocks. Extractive fermentation of C. acetobutylicum is operated in fed-batch mode with a concentrated feed solution (500 grams per liter glucose and 50 grams per liter yeast extract) for 60 h, producing in excess of 40 g of solvents (acetone, butanol and ethanol) between the completely immiscible extractant and aqueous phases of the bioreactor. After distillation of the extractant phase, the acetone, butanol and ethanol mixture is upgraded to long-chain ketones over a palladium-hydrotalcite (Pd-HT) catalyst. This reaction is generally carried out in batch with a high-pressure Q-tube for 20 h at 250 °C. Following this protocol enables the production of ∼0.5 g of high-value biofuel precursors from a 1.7-g portion of fermentation solvents.

  6. Production of butanol by Clostridium saccharoperbutylacetonicum N1-4 from palm kernel cake in acetone-butanol-ethanol fermentation using an empirical model.

    PubMed

    Shukor, Hafiza; Al-Shorgani, Najeeb Kaid Nasser; Abdeshahian, Peyman; Hamid, Aidil Abdul; Anuar, Nurina; Rahman, Norliza Abd; Kalil, Mohd Sahaid

    2014-10-01

    Palm kernel cake (PKC) was used for biobutanol production by Clostridium saccharoperbutylacetonicum N1-4 in acetone-butanol-ethanol (ABE) fermentation. PKC was subjected to acid hydrolysis pretreatment and hydrolysates released were detoxified by XAD-4 resin. The effect of pH, temperature and inoculum size on butanol production was evaluated using an empirical model. Twenty ABE fermentations were run according to an experimental design. Experimental results revealed that XAD-4 resin removed 50% furfural and 77.42% hydroxymethyl furfural. The analysis of the empirical model showed that linear effect of inoculums size with quadratic effect of pH and inoculum size influenced butanol production at 99% probability level (P<0.01). The optimum conditions for butanol production were pH 6.28, temperature of 28°C and inoculum size of 15.9%. ABE fermentation was carried out under optimum conditions which 0.1g/L butanol was obtained. Butanol production was enhanced by diluting PKC hydrolysate up to 70% in which 3.59g/L butanol was produced.

  7. Two-stage pervaporation process for effective in situ removal acetone-butanol-ethanol from fermentation broth.

    PubMed

    Cai, Di; Hu, Song; Miao, Qi; Chen, Changjing; Chen, Huidong; Zhang, Changwei; Li, Ping; Qin, Peiyong; Tan, Tianwei

    2017-01-01

    Two-stage pervaporation for ABE recovery from fermentation broth was studied to reduce the energy cost. The permeate after the first stage in situ pervaporation system was further used as the feedstock in the second stage of pervaporation unit using the same PDMS/PVDF membrane. A total 782.5g/L of ABE (304.56g/L of acetone, 451.98g/L of butanol and 25.97g/L of ethanol) was achieved in the second stage permeate, while the overall acetone, butanol and ethanol separation factors were: 70.7-89.73, 70.48-84.74 and 9.05-13.58, respectively. Furthermore, the theoretical evaporation energy requirement for ABE separation in the consolidate fermentation, which containing two-stage pervaporation and the following distillation process, was estimated less than ∼13.2MJ/kg-butanol. The required evaporation energy was only 36.7% of the energy content of butanol. The novel two-stage pervaporation process was effective in increasing ABE production and reducing energy consumption of the solvents separation system.

  8. Substrate dependent modulation of butanol to ethanol ratio in non-acetone forming Clostridium sporogenes NCIM 2918.

    PubMed

    Kaushal, Mehak; Ahlawat, Saumya; Mukherjee, Mayurketan; Muthuraj, Muthusivaramapandian; Goswami, Gargi; Das, Debasish

    2017-02-01

    Present study reports a non-acetone producing Clostridium sporogenes strain as a potential producer of liquid biofuels. Alcohol production was positively regulated by sorbitol and instant dry yeast as carbon and nitrogen sources respectively. Media optimization resulted in maximum butanol and ethanol titer (gL(-1)) of 12.1 and 7.9 respectively. Depending on the combination of carbon sources, the organism was found to manipulate its metabolism towards synthesis of either ethanol or butanol, thereby affecting the total alcohol titer. Among various dual substrate combinations, glucose-glycerol mixture in the ratio of 60:40 resulted in maximum butanol and ethanol titer (gL(-1)) of 11.9 and 12.1 respectively with total alcohol productivity of 0.59gL(-1)h(-1). In the mixture, when pure glycerol was replaced with crude glycerol, butanol and ethanol titer (gL(-1)) of 11.2 and 11.7 was achieved. Hence, the strain shows immense potential for biofuels production using crude glycerol as cheap substrate.

  9. Continuous two stage acetone-butanol-ethanol fermentation with integrated solvent removal using Clostridium acetobutylicum B 5313.

    PubMed

    Bankar, Sandip B; Survase, Shrikant A; Singhal, Rekha S; Granström, Tom

    2012-02-01

    The objective of this study was to optimize continuous acetone-butanol-ethanol (ABE) fermentation using a two stage chemostat system integrated with liquid-liquid extraction of solvents produced in the first stage. This minimized end product inhibition by butanol and subsequently enhanced glucose utilization and solvent production in continuous cultures of Clostridium acetobutylicum B 5313. During continuous two-stage ABE fermentation, sugarcane bagasse was used as the cell holding material for the both stages and liquid-liquid extraction was performed using an oleyl alcohol and decanol mixture. An overall solvent production of 25.32g/L (acetone 5.93g/L, butanol 16.90g/L and ethanol 2.48g/L) was observed as compared to 15.98g/L in the single stage chemostat with highest solvent productivity and solvent yield of 2.5g/Lh and of 0.35g/g, respectively. Maximum glucose utilization (83.21%) at a dilution rate of 0.051/h was observed as compared to 54.38% in the single stage chemostat.

  10. Simultaneous fermentation and separation in an immobilized cell trickle bed reactor: Acetone-butanol-ethane (ABE) and ethanol fermentation

    SciTech Connect

    Park, C.H.

    1989-01-01

    A novel process employing immobilized cells and in-situ product removal was studied for acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum and ethanol fermentation by Saccharomyces cerevisiae. Experimental studies of ABE fermentation in a trickle bed reactor without product separation showed that solvent production could be improved by one order of magnitude compared to conventional batch fermentation. Control of effluent pH near 4.3 and feed glucose concentrations higher than 10 g/L were the necessary conditions for cell growth and solvent production. A mathematical model using an equilibrium staged model predicted efficient separation of butanol from the fermentation broth. Activity coefficients of multicomponent system were estimated by Wilson's equation or the ASOG method. Inhibition by butanol and organic acids was incorporated into the kinetic expression. Experimental performance of simultaneous fermentation and separation in an immobilized cell trickle bed reactor showed that glucose conversion was improved as predicted by mathematical modeling and analysis. The effect of pH and temperature on ethanol fermentation by Saccharomyces cerevisiae was studied in free and immobilized cell reactors. Conditions for the highest glucose conversion, cell viability and least glycerol yield were determined.

  11. Assessment of morphological changes of Clostridium acetobutylicum by flow cytometry during acetone/butanol/ethanol extractive fermentation.

    PubMed

    González-Peñas, Helena; Lu-Chau, Thelmo Alejandro; Moreira, Maria Teresa; Lema, Juan Manuel

    2015-03-01

    Acetone/butanol/ethanol (ABE) fermentation by Clostridium acetobutylicum was investigated in extractive fed-batch experiments. In conventional fermentations, metabolic activity ceases when a critical threshold products concentration is reached (~21.6 g solvents l(-1)). Solvents production was increased up to 36.6 and 37.2 g l(-1), respectively, using 2-butyl-1-octanol (aqueous to organic ratio: 1:0.25 v/v) and pomace olive oil (1:1 v/v) as extraction solvents. The morphological changes of different cell types were monitored and quantified using flow cytometry. Butanol production in extractive fermentations with pomace olive oil was achieved mainly by vegetative cells, whereas the percentage of sporulating cells was lower than 10%.

  12. Acetone, butanol, and ethanol production from gelatinized cassava flour by a new isolates with high butanol tolerance.

    PubMed

    Li, Han-Guang; Ofosu, Fred Kwame; Li, Kun-Tai; Gu, Qiu-Ya; Wang, Qiang; Yu, Xiao-Bin

    2014-11-01

    To obtain native strains resistant to butanol toxicity, a new isolating method and serial enrichment was used in this study. With this effort, mutant strain SE36 was obtained, which could withstand 35g/L (compared to 20g/L of the wild-type strain) butanol challenge. Based on 16s rDNA comparison, the mutant strain was identified as Clostridium acetobutylicum. Under the optimized condition, the phase shift was smoothly triggered and fermentation performances were consequently enhanced. The maximum total solvent and butanol concentration were 23.6% and 24.3%, respectively higher than that of the wild-type strain. Furthermore, the correlation between butanol produced and the butanol tolerance was investigated, suggesting that enhancing butanol tolerance could improve butanol production. These results indicate that the simple but effective isolation method and acclimatization process are a promising technique for isolation and improvement of butanol tolerance and production.

  13. Efficient production of acetone-butanol-ethanol (ABE) from cassava by a fermentation-pervaporation coupled process.

    PubMed

    Li, Jing; Chen, Xiangrong; Qi, Benkun; Luo, Jianquan; Zhang, Yuming; Su, Yi; Wan, Yinhua

    2014-10-01

    Production of acetone-butanol-ethanol (ABE) from cassava was investigated with a fermentation-pervaporation (PV) coupled process. ABE products were in situ removed from fermentation broth to alleviate the toxicity of solvent to the Clostridium acetobutylicum DP217. Compared to the batch fermentation without PV, glucose consumption rate and solvent productivity increased by 15% and 21%, respectively, in batch fermentation-PV coupled process, while in continuous fermentation-PV coupled process running for 304 h, the substrate consumption rate, solvent productivity and yield increased by 58%, 81% and 15%, reaching 2.02 g/Lh, 0.76 g/Lh and 0.38 g/g, respectively. Silicalite-1 filled polydimethylsiloxane (PDMS)/polyacrylonitrile (PAN) membrane modules ensured media recycle without significant fouling, steadily generating a highly concentrated ABE solution containing 201.8 g/L ABE with 122.4 g/L butanol. After phase separation, a final product containing 574.3g/L ABE with 501.1g/L butanol was obtained. Therefore, the fermentation-PV coupled process has the potential to decrease the cost in ABE production.

  14. Acetone-butanol-ethanol fermentation in a continuous and closed-circulating fermentation system with PDMS membrane bioreactor.

    PubMed

    Chen, Chunyan; Xiao, Zeyi; Tang, Xiaoyu; Cui, Haidi; Zhang, Junqing; Li, Weijia; Ying, Chao

    2013-01-01

    Acetone-butanol-ethanol (ABE) fermentation by combining a PDMS membrane bioreactor and Clostridium acetobutylicum was studied, and a long continuous and closed-circulating fermentation (CCCF) system has been achieved. Two cycles of experiment were conducted, lasting for 274 h and 300 h, respectively. The operation mode of the first cycle was of fermentation intermittent coupling with pervaporation, and the second cycle was of continuous coupling. The average cell weight, glucose consumption rate, butanol productivity and butanol production of the first cycle were 1.59 g L(-1), 0.63 g L(-1)h(-1), 0.105 g L(-1)h(-1) and 28.03 g L(-1), respectively. Correspondingly, the four parameters of the second cycle were 1.68 g L(-1), 1.12 g L(-1)h(-1), 0.205 g L(-1)h(-1) and 61.43 g L(-1), respectively. The results indicate the fermentation behaviors under continuous coupling mode were superior to that under intermittent coupling mode. Besides, two peak values were observed in the time course profiles, which means the microorganism could adapt the long CCCF membrane bioreactor system.

  15. Production of acetone-butanol-ethanol (ABE) in direct fermentation of cassava by Clostridium saccharoperbutylacetonicum N1-4.

    PubMed

    Thang, Vu Hong; Kanda, Kohzo; Kobayashi, Genta

    2010-05-01

    In this work, acetone-butanol-ethanol (ABE) fermentation characteristics of cassava starch and cassava chips when using Clostridium saccharoperbutylacetonicum N1-4 was presented. The obtained results in batch mode using a 1-L fermenter showed that C. saccharoperbutylacetonicum N1-4 was a hyperamylolytic strain and capable of producing solvents efficiently from cassava starch and cassava chips, which was comparable to when glucose was used. Batch fermentation of cassava starch and cassava chips resulted in 21.0 and 19.4 g/L of total solvent as compared with 24.2 g/L of total solvent when using glucose. Solvent productivity in fermentation of cassava starch was from 42% to 63% higher than that obtained in fermentation using corn and sago starches in the same condition. In fermentation of cassava starch and cassava chips, maximum butanol concentration was 16.9 and 15.5 g/L, respectively. Solvent yield and butanol yield (based on potential glucose) was 0.33 and 0.41, respectively, for fermentation of cassava starch and 0.30 and 0.38, respectively for fermentation using cassava chips.

  16. Direct in situ butanol recovery inside the packed bed during continuous acetone-butanol-ethanol (ABE) fermentation.

    PubMed

    Wang, Yin-Rong; Chiang, Yu-Sheng; Chuang, Po-Jen; Chao, Yun-Peng; Li, Si-Yu

    2016-09-01

    In this study, the integrated in situ extraction-gas stripping process was coupled with continuous ABE fermentation using immobilized Clostridium acetobutylicum. At the same time, oleyl alcohol was cocurrently flowed into the packed bed reactor with the fresh medium and then recycled back to the packed bed reactor after removing butanol in the stripper. A high glucose consumption of 52 g/L and a high butanol productivity of 11 g/L/h were achieved, resulting in a high butanol yield of 0.21 g-butanol/g-glucose. This can be attributed to both the high bacterial activity for solvent production as well as a threefold increase in the bacterial density inside the packed bed reactor. Also reported is that 64 % of the butanol produced can be recovered by the integrated in situ extraction-gas stripping process. A high butanol productivity and a high glucose consumption were simultaneously achieved.

  17. Direct fermentation of gelatinized cassava starch to acetone, butanol, and ethanol using Clostridium acetobutylicum mutant obtained by atmospheric and room temperature plasma.

    PubMed

    Li, Han-guang; Luo, Wei; Wang, Qiang; Yu, Xiao-bin

    2014-04-01

    The mutant strain designated as ART18, obtained from the wild-type strain Clostridium acetobutylicum PW12 treated by atmospheric and room temperature plasma, showed higher solvent tolerance and butanol production than that of the wild-type strain. The production of butanol was 11.3 ± 0.5 g/L, 31 % higher than that of the wild-type strain when it was used for acetone, butanol, and ethanol fermentation in P2 medium. Furthermore, the effects of cassava flour concentration, pH regulators, and vitamins on the ABE production were also investigated. The highest butanol production of 15.8 ± 0.8 g/L and butanol yield (0.31 g/g) were achieved after the above factors were optimized. When acetone, butanol, and ethanol fermentation by ART18 was carried out in a 15-L bioreactor, the butanol production, the productivity of butanol, and the total solvent were 16.3 ± 0.9, 0.19, and 0.28 g/L(/)h, respectively. These results indicate that ART18 is a promising industrial producer in ABE fermentation.

  18. Effect of cellulosic sugar degradation products (furfural and hydroxymethylfurfural) on acetone-butanol-ethanol (ABE) fermentation using Clostridium beijerinckii P260

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were performed to identify chemicals present in wheat straw hydrolysate (WSH) that enhance acetone butanol ethanol (ABE) productivity. These chemicals were identified as furfural and hydroxymethyl furfural (HMF). Control experiment resulted in the production of 21.09-21.66 gL**-1 ABE with a ...

  19. Acetone-butanol-ethanol from sweet sorghum juice by an immobilized fermentation-gas stripping integration process.

    PubMed

    Cai, Di; Wang, Yong; Chen, Changjing; Qin, Peiyong; Miao, Qi; Zhang, Changwei; Li, Ping; Tan, Tianwei

    2016-07-01

    In this study, sweet sorghum juice (SSJ) was used as the substrate in a simplified ABE fermentation-gas stripping integration process without nutrients supplementation. The sweet sorghum bagasse (SSB) after squeezing the fermentable juice was used as the immobilized carrier. The results indicated that the productivity of ABE fermentation process was improved by gas stripping integration. A total 24g/L of ABE solvents was obtained from 59.6g/L of initial sugar after 80h of fermentation with gas stripping. Then, long-term of fed-batch fermentation with continuous gas stripping was further performed. 112.9g/L of butanol, 44.1g/L of acetone, 9.5g/L of ethanol (total 166.5g/L of ABE) was produced in overall 312h of fermentation. At the same time, concentrated ABE product was obtained in the condensate of gas stripping.

  20. Oil palm empty fruit bunch as alternative substrate for acetone-butanol-ethanol production by Clostridium butyricum EB6.

    PubMed

    Ibrahim, Mohamad Faizal; Abd-Aziz, Suraini; Razak, Mohamad Nafis Abdul; Phang, Lai Yee; Hassan, Mohd Ali

    2012-04-01

    Acetone-butanol-ethanol (ABE) production from renewable resources has been widely reported. In this study, Clostridium butyricum EB6 was employed for ABE fermentation using fermentable sugar derived from treated oil palm empty fruit bunch (OPEFB). A higher amount of ABE (2.61 g/l) was produced in a fermentation using treated OPEFB as the substrate when compared to a glucose based medium that produced 0.24 g/l at pH 5.5. ABE production was increased to 3.47 g/l with a yield of 0.24 g/g at pH 6.0. The fermentation using limited nitrogen concentration of 3 g/l improved the ABE yield by 64%. The study showed that OPEFB has the potential to be applied for renewable ABE production by C. butyricum EB6.

  1. A comparison of the energy use of in situ product recovery techniques for the Acetone Butanol Ethanol fermentation.

    PubMed

    Outram, Victoria; Lalander, Carl-Axel; Lee, Jonathan G M; Davis, E Timothy; Harvey, Adam P

    2016-11-01

    The productivity of the Acetone Butanol Ethanol (ABE) fermentation can be significantly increased by application of various in situ product recovery (ISPR) techniques. There are numerous technically viable processes, but it is not clear which is the most economically viable in practice. There is little available information about the energy requirements and economics of ISPR for the ABE fermentation. This work compares various ISPR techniques based on UniSim process simulations of the ABE fermentation. The simulations provide information on the process energy and separation efficiency, which is fed into an economic assessment. Perstraction was the only technique to reduce the energy demand below that of a batch process, by approximately 5%. Perstraction also had the highest profit increase over a batch process, by 175%. However, perstraction is an immature technology, so would need significant development before being integrated to an industrial process.

  2. A quantitative metabolomics study of high sodium response in Clostridium acetobutylicum ATCC 824 acetone-butanol-ethanol (ABE) fermentation

    PubMed Central

    Zhao, Xinhe; Condruz, Stefan; Chen, Jingkui; Jolicoeur, Mario

    2016-01-01

    Hemicellulose hydrolysates, sugar-rich feedstocks used in biobutanol refinery, are normally obtained by adding sodium hydroxide in the hydrolyze process. However, the resulting high sodium concentration in the hydrolysate inhibits ABE (acetone-butanol-ethanol) fermentation, and thus limits the use of these low-cost feedstocks. We have thus studied the effect of high sodium on the metabolic behavior of Clostridium acetobutyricum ATCC 824, with xylose as the carbon source. At a threshold sodium concentration of 200 mM, a decrease of the maximum cell dry weight (−19.50 ± 0.85%) and of ABE yield (−35.14 ± 3.50% acetone, −33.37 ± 0.74% butanol, −22.95 ± 1.81% ethanol) were observed compared to control culture. However, solvents specific productivities were not affected by supplementing sodium. The main effects of high sodium on cell metabolism were observed in acidogenesis, during which we observed the accumulation of ATP and NADH, and the inhibition of the pentose phosphate (PPP) and the glycolytic pathways with up to 80.73 ± 1.47% and 68.84 ± 3.42% decrease of the associated metabolic intermediates, respectively. However, the NADP+-to-NADPH ratio was constant for the whole culture duration, a phenomenon explaining the robustness of solvents specific productivities. Therefore, high sodium, which inhibited biomass growth through coordinated metabolic effects, interestingly triggered cell robustness on solvents specific productivity. PMID:27321153

  3. Production of acetone butanol ethanol (ABE) by a hyper-producing mutant strain of Clostridium beijerinckii BA101 and recovery by pervaporation

    SciTech Connect

    Qureshi, N.; Blaschek, H.P.

    1999-07-01

    A silicone membrane was used to study butanol separation from model butanol solutions and fermentation broth. Depending upon the butanol feed concentration in the model solution and pervaporation conditions, butanol selectivities of 20.88--68.32 and flux values of 158.7--215.4 g m{sup {minus}2} h{sup {minus}1} were achieved. Higher flux values were obtained at higher butanol concentrations using air as sweep gas. In an integrated process of butanol fermentation--recovery, solvent productivities were improved to 200% of the control batch fermentation productivities. In a batch reactor the hyper-butanol-producing mutant strain C. beijerinckii BA101 utilized 57.3 g/L glucose and produced 24.2 g/L total solvents, while in the integrated process it produced 51.5 g/L (culture volume) total solvents. Concentrated glucose medium was also fermented. The C. beijerinckii BA101 mutant strain was not negatively affected by the pervaporative conditions. In the integrated experiment, acids were not produced. With the active fermentation broth, butanol selectivity was reduced by a factor of 2--3. However, the membrane flux was not affected by the active fermentation broth. The butanol permeate concentration ranged from 26.4 to 95.4 g/L, depending upon butanol concentration in the fermentation broth. Since the permeate of most membranes contains acetone, butanol, and ethanol, it is suggested that distillation be used for further purification.

  4. Production of acetone butanol ethanol (ABE) by a hyper-producing mutant strain of Clostridium beijerinckii BA101 and recovery by pervaporation.

    PubMed

    Qureshi, N; Blaschek, H P

    1999-01-01

    A silicone membrane was used to study butanol separation from model butanol solutions and fermentation broth. Depending upon the butanol feed concentration in the model solution and pervaporation conditions, butanol selectivities of 20.88-68.32 and flux values of 158.7-215.4 g m(-)(2) h(-)(1) were achieved. Higher flux values (400 g m(-)(2) h(-)(1)) were obtained at higher butanol concentrations using air as sweep gas. In an integrated process of butanol fermentation-recovery, solvent productivities were improved to 200% of the control batch fermentation productivities. In a batch reactor the hyper-butanol-producing mutant strain C. beijerinckii BA101 utilized 57.3 g/L glucose and produced 24.2 g/L total solvents, while in the integrated process it produced 51.5 g/L (culture volume) total solvents. Concentrated glucose medium was also fermented. The C. beijerinckii BA101 mutant strain was not negatively affected by the pervaporative conditions. In the integrated experiment, acids were not produced. With the active fermentation broth, butanol selectivity was reduced by a factor of 2-3. However, the membrane flux was not affected by the active fermentation broth. The butanol permeate concentration ranged from 26.4 to 95.4 g/L, depending upon butanol concentration in the fermentation broth. Since the permeate of most membranes contains acetone, butanol, and ethanol (and small concentrations of acids), it is suggested that distillation be used for further purification.

  5. Enhancing acetone biosynthesis and acetone-butanol-ethanol fermentation performance by co-culturing Clostridium acetobutylicum/Saccharomyces cerevisiae integrated with exogenous acetate addition.

    PubMed

    Luo, Hongzhen; Ge, Laibing; Zhang, Jingshu; Ding, Jian; Chen, Rui; Shi, Zhongping

    2016-01-01

    Acetone is the major by-product in ABE fermentations, most researches focused on increasing butanol/acetone ratio by decreasing acetone biosynthesis. However, economics of ABE fermentation industry strongly relies on evaluating acetone as a valuable platform chemical. Therefore, a novel ABE fermentation strategy focusing on bio-acetone production by co-culturing Clostridium acetobutylicum/Saccharomyces cerevisiae with exogenous acetate addition was proposed. Experimental and theoretical analysis revealed the strategy could, enhance C. acetobutylicum survival oriented amino acids assimilation in the cells; control NADH regeneration rate at moderately lower level to enhance acetone synthesis but without sacrificing butanol production; enhance the utilization ability of C. acetobutylicum on glucose and direct most of extra consumed glucose into acetone/butanol synthesis routes. By implementing the strategy using synthetic or acetate fermentative supernatant, acetone concentrations increased to 8.27-8.55g/L from 5.86g/L of the control, while butanol concentrations also elevated to the higher levels of 13.91-14.23g/L from 11.63g/L simultaneously.

  6. Acetone-butanol-ethanol competitive sorption simulation from single, binary, and ternary systems in a fixed-bed of KA-I resin.

    PubMed

    Wu, Jinglan; Zhuang, Wei; Ying, Hanjie; Jiao, Pengfei; Li, Renjie; Wen, Qingshi; Wang, Lili; Zhou, Jingwei; Yang, Pengpeng

    2015-01-01

    Separation of butanol based on sorption methodology from acetone-butanol-ethanol (ABE) fermentation broth has advantages in terms of biocompatibility and stability, as well as economy, and therefore gains much attention. In this work a chromatographic column model based on the solid film linear driving force approach and the competitive Langmuir isotherm equations was used to predict the competitive sorption behaviors of ABE single, binary, and ternary mixture. It was observed that the outlet concentration of weaker retained components exceeded the inlet concentration, which is an evidence of competitive adsorption. Butanol, the strongest retained component, could replace ethanol almost completely and also most of acetone. In the end of this work, the proposed model was validated by comparison of the experimental and predicted ABE ternary breakthrough curves using the real ABE fermentation broth as a feed solution.

  7. Continuous acetone-butanol-ethanol (ABE) fermentation and gas production under slight pressure in a membrane bioreactor.

    PubMed

    Chen, Chunyan; Wang, Linyuan; Xiao, Guoqing; Liu, Yucheng; Xiao, Zeyi; Deng, Qing; Yao, Peina

    2014-07-01

    Two rounds of acetone-butanol-ethanol (ABE) fermentation under slight pressure were carried out in the continuous and closed-circulating fermentation (CCCF) system. Spores of the clostridium were observed and counted, with the maximum number of 2.1 × 10(8) and 2.3 × 10(8)ml(-1) separately. The fermentation profiles were comparable with that at atmospheric pressure, showing an average butanol productivity of 0.14 and 0.13 g L(-1)h(-1). Moreover, the average gas productivities of 0.28 and 0.27 L L(-1)h(-1) were obtained in two rounds of CCCF, and the cumulative gas production of 52.64 and 25.92 L L(-1) were achieved, with the hydrogen volume fraction of 41.43% and 38.08% respectively. The results suggested that slight pressures have no obvious effect on fermentation performance, and also indicated the significance and feasibility of gas recovery in the continuous ABE fermentation process.

  8. Microbial production of a biofuel (acetone-butanol-ethanol) in a continuous bioreactor: impact of bleed and simultaneous product removal.

    PubMed

    Ezeji, Thaddeus Chukwuemeka; Qureshi, Nasib; Blaschek, Hans Peter

    2013-01-01

    Acetone butanol ethanol (ABE) was produced in an integrated continuous one-stage fermentation and gas stripping product recovery system using Clostridium beijerinckii BA101 and fermentation gases (CO(2) and H(2)). In this system, the bioreactor was fed with a concentrated sugar solution (250-500 g L(-1) glucose). The bioreactor was bled semi-continuously to avoid accumulation of inhibitory chemicals and products. The continuous system was operated for 504 h (21 days) after which the fermentation was intentionally terminated. The bioreactor produced 461.3 g ABE from 1,125.0 g total sugar in 1 L culture volume as compared to a control batch process in which 18.4 g ABE was produced from 47.3 g sugar. These results demonstrate that ABE fermentation can be operated in an integrated continuous one-stage fermentation and product recovery system for a long period of time, if butanol and other microbial metabolites in the bioreactor are kept below threshold of toxicity.

  9. Allopurinol-mediated lignocellulose-derived microbial inhibitor tolerance by Clostridium beijerinckii during acetone-butanol-ethanol (ABE) fermentation.

    PubMed

    Ujor, Victor; Agu, Chidozie Victor; Gopalan, Venkat; Ezeji, Thaddeus Chukwuemeka

    2015-04-01

    In addition to glucans, xylans, and arabinans, lignocellulosic biomass hydrolysates contain significant levels of nonsugar components that are toxic to the microbes that are typically used to convert biomass to biofuels and chemicals. To enhance the tolerance of acetone-butanol-ethanol (ABE)-generating Clostridium beijerinckii NCIMB 8052 to these lignocellulose-derived microbial inhibitory compounds (LDMICs; e.g., furfural), we have been examining different metabolic perturbation strategies to increase the cellular reductant pools and thereby facilitate detoxification of LDMICs. As part of these efforts, we evaluated the effect of allopurinol, an inhibitor of NAD(P)H-generating xanthine dehydrogenase (XDH), on C. beijerinckii grown in furfural-supplemented medium and found that it unexpectedly increased the rate of detoxification of furfural by 1.4-fold and promoted growth, butanol, and ABE production by 1.2-, 2.5-, and 2-fold, respectively. Since NAD(P)H/NAD(P)(+) levels in C. beijerinckii were largely unchanged upon allopurinol treatment, we postulated and validated a possible basis in DNA repair to account for the solventogenic gains with allopurinol. Following the observation that supplementation of allopurinol in the C. beijerinckii growth media mitigates the toxic effects of nalidixic acid, a DNA-damaging antibiotic, we found that allopurinol elicited 2.4- and 6.7-fold increase in the messenger RNA (mRNA) levels of xanthine and hypoxanthine phosphoribosyltransferases, key purine-salvage enzymes. Consistent with this finding, addition of inosine (a precursor of hypoxanthine) and xanthine led to 1.4- and 1.7-fold increase in butanol production in furfural-challenged cultures of C. beijerinckii. Taken together, our results provide a purine salvage-based rationale for the unanticipated effect of allopurinol in improving furfural tolerance of the ABE-fermenting C. beijerinckii.

  10. Acetone-butanol-ethanol fermentation of corn stover by Clostridium species: present status and future perspectives.

    PubMed

    Li, Jianzheng; Baral, Nawa Raj; Jha, Ajay Kumar

    2014-04-01

    Sustainable vehicle fuel is indispensable in future due to worldwide depletion of fossil fuel reserve, oil price fluctuation and environmental degradation. Microbial production of butanol from renewable biomass could be one of the possible options. Renewable biomass such as corn stover has no food deficiency issues and is also cheaper in most of the agricultural based countries. Thus it can effectively solve the existing issue of substrate cost. In the last 30 years, a few of Clostridium strains have been successfully implemented for biobutanol fermentation. However, the commercial production is hindered due to their poor tolerance to butanol and inhibitors. Metabolic engineering of Clostridia strains is essential to solve above problems and ultimately enhance the solvent production. An effective and efficient pretreatment of raw material as well as optimization of fermentation condition could be another option. Furthermore, biological approaches may be useful to optimize both the host and pathways to maximize butanol production. In this context, this paper reviews the existing Clostridium strains and their ability to produce butanol particularly from corn stover. This study also highlights possible fermentation pathways and biological approaches that may be useful to optimize fermentation pathways. Moreover, challenges and future perspectives are also discussed.

  11. Enhancing clostridial acetone-butanol-ethanol (ABE) production and improving fuel properties of ABE-enriched biodiesel by extractive fermentation with biodiesel.

    PubMed

    Li, Qing; Cai, Hao; Hao, Bo; Zhang, Congling; Yu, Ziniu; Zhou, Shengde; Chenjuan, Liu

    2010-12-01

    The extractive acetone-butanol-ethanol (ABE) fermentations of Clostridium acetobutylicum were evaluated using biodiesel as the in situ extractant. The biodiesel preferentially extracted butanol, minimized product inhibition, and increased production of butanol (from 11.6 to 16.5 g L⁻¹) and total solvents (from 20.0 to 29.9 g L⁻¹) by 42% and 50%, respectively. The fuel properties of the ABE-enriched biodiesel obtained from the extractive fermentations were analyzed. The key quality indicators of diesel fuel, such as the cetane number (increased from 48 to 54) and the cold filter plugging point (decreased from 5.8 to 0.2 °C), were significantly improved for the ABE-enriched biodiesel. Thus, the application of biodiesel as the extractant for ABE fermentation would increase ABE production, bypass the energy intensive butanol recovery process, and result in an ABE-enriched biodiesel with improved fuel properties.

  12. Effective multiple stages continuous acetone-butanol-ethanol fermentation by immobilized bioreactors: Making full use of fresh corn stalk.

    PubMed

    Chang, Zhen; Cai, Di; Wang, Yong; Chen, Changjing; Fu, Chaohui; Wang, Guoqing; Qin, Peiyong; Wang, Zheng; Tan, Tianwei

    2016-04-01

    In order to make full use of the fresh corn stalk, the sugar containing juice was used as the sole substrate for acetone-butanol-ethanol production without any nutrients supplement, and the bagasse after squeezing the juice was used as the immobilized carrier. A total 21.34g/L of ABE was produced in batch cells immobilization system with ABE yield of 0.35g/g. A continuous fermentation containing three stages with immobilized cells was conducted and the effect of dilution rate on fermentation was investigated. As a result, the productivity and ABE solvents concentration reached 0.80g/Lh and 19.93g/L, respectively, when the dilution rate in each stage was 0.12/h (corresponding to a dilution rate of 0.04/h in the whole system). And the long-term operation indicated the continuous multiple stages ABE fermentation process had good stability and showed the great potential in future industrial applications.

  13. Optimization and validation of a GC-FID method for the determination of acetone-butanol-ethanol fermentation products.

    PubMed

    Lin, Xiaoqing; Fan, Jiansheng; Wen, Qingshi; Li, Renjie; Jin, Xiaohong; Wu, Jinglan; Qian, Wenbin; Liu, Dong; Xie, Jingjing; Bai, Jianxin; Ying, Hanjie

    2014-03-01

    An improved, simple gas chromatography-flame ionization detection (GC-FID) method was developed for measuring the products of acetone-butanol-ethanol (ABE) fermentation and the combined fermentation/separation processes. The analysis time per sample was reduced to less than 10 min compared to those of a conventional GC-FID (more than 20 min). The behavior of the compounds in temperature-programmed gas chromatographic runs was predicted using thermodynamic parameters derived from isothermal runs. The optimum temperature programming condition was achieved when the resolution for each peak met the analytical requirement and the analysis time was shortest. With the exception of acetic acid, the detection limits of the presented method for various products were below 10 mg/L. The repeatability and intermediate precision of the method were less than 10% (relative standard deviation). Validation and quantification results demonstrated that this method is a sensitive, reliable and fast alternative for conventional investigation of the adsorption-coupled ABE fermentation process.

  14. Enhanced enzymatic hydrolysis and acetone-butanol-ethanol fermentation of sugarcane bagasse by combined diluted acid with oxidate ammonolysis pretreatment.

    PubMed

    Li, Hailong; Xiong, Lian; Chen, Xuefang; Wang, Can; Qi, Gaoxiang; Huang, Chao; Luo, Mutan; Chen, Xinde

    2017-03-01

    This study aims to propose a biorefinery pretreatment technology for the bioconversion of sugarcane bagasse (SB) into biofuels and N-fertilizers. Performance of diluted acid (DA), aqueous ammonia (AA), oxidate ammonolysis (OA) and the combined DA with AA or OA were compared in SB pretreatment by enzymatic hydrolysis, structural characterization and acetone-butanol-ethanol (ABE) fermentation. Results indicated that DA-OA pretreatment improves the digestibility of SB by sufficiently hydrolyzing hemicellulose into fermentable monosaccharides and oxidating lignin into soluble N-fertilizer with high nitrogen content (11.25%) and low C/N ratio (3.39). The enzymatic hydrolysates from DA-OA pretreated SB mainly composed of glucose was more suitable for the production of ABE solvents than the enzymatic hydrolysates from OA pretreated SB containing high ratio of xylose. The fermentation of enzymatic hydrolysates from DA-OA pretreated SB produced 12.12g/L ABE in 120h. These results suggested that SB could be utilized efficient, economic, and environmental by DA-OA pretreatment.

  15. Genome shuffling of Clostridium acetobutylicum CICC 8012 for improved production of acetone-butanol-ethanol (ABE).

    PubMed

    Gao, Xiaofeng; Zhao, Hai; Zhang, Guohua; He, Kaize; Jin, Yanling

    2012-08-01

    Genome shuffling was applied to increase ABE production of the strict anaerobe C. acetobutylicum CICC 8012. By using physical and chemical mutagenesis, strains with superior streptomycin sulfate, 2-deoxy-D-glucose and butanol tolerance levels were isolated. These strains were used for genome shuffling. The best performing strain F2-GA was screened after two rounds of genome shuffling. With 55 g glucose/l as carbon source, F2-GA produced 22.21 g ABE/l in 72 h and ABE yield reached 0.42 g/g which was about 34.53 % improvement compared to the wild type. Fermentation parameters and gene expression of several key enzymes in ABE metabolic pathways were varied significantly between F2-GA and the wild type. These results demonstrated the potential use of genome shuffling to microbial breeding which were difficult to deal with traditional methods.

  16. Periodic peristalsis increasing acetone-butanol-ethanol productivity during simultaneous saccharification and fermentation of steam-exploded corn straw.

    PubMed

    Li, Jingwen; Wang, Lan; Chen, Hongzhang

    2016-11-01

    The acetone-butanol-ethanol (ABE) fermentation of lignocellulose at high solids content has recently attracted extensive attention. However, the productivity of high solids ABE fermentation of lignocellulose is typically low in traditional processes due to the lack of efficient intensifying methods. In the present study, periodic peristalsis, a novel intensifying method, was applied to improve ABE production by the simultaneous saccharification and fermentation (SSF) of steam-exploded corn straw using Clostridium acetobutylicum ATCC824. The ABE concentration and the ABE productivity of SSF at a solids content of 17.5% (w/w) with periodic peristalsis were 17.1 g/L and 0.20 g/(L h), respectively, which were higher than those obtained under static conditions (15.2 g/L and 0.14 g/(L h)). The initial sugar conversion rate over the first 12 h with periodic peristalsis was 4.67 g/(L h) at 10 FPU/g cellulase dosage and 15% (w/w) solids content, an increase of 49.7% compared with the static conditions. With periodic peristalsis, the period of batch fermentation was shortened from 108 h to 84 h. The optimal operating regime was a low frequency (6 h(-1)) of periodic peristalsis in the acid-production phase (0-48 h) of SSF. Therefore, periodic peristalsis should be an effective intensifying method to increase the productivity of ABE fermentation at high solids content.

  17. Enzymology of acetone-butanol-isopropanol formation

    SciTech Connect

    Chen, Jiann-Shin.

    1992-01-01

    The long-term goal of the project is to understand the fundamental properties of biological solvent production. Our approach is to elucidate first the molecular properties of solvent-producing enzymes and then to apply to information gained from the enzymological study to investigate control mechanisms for the solvent-producing pathways and the expression of solvent-production genes. Our research primarily involves two strains of Clostridium beijerinckii: C. Beijerinckii NRRL B593 which produces isopropanol in addition to acetone, butanol, and ethanol, and C. beijerinckii NRRL B592 which produces acetone, butanol and ethanol, but not isopropanol. In more recent studies, we also included another solvent-producing organism, Bacillus macerans. Objectives for the reporting period were: to characterize the distinct types of alcohol dehydrogenase; to purify and characterize acetoacetyl-CoA-reacting enzymes; and to clone and sequence the gene encoding the primary/secondary alcohol dehydrogenase of C beijerinckii NRRL B593 and to search for the promoter region for solvent-production genes.

  18. Acetone-butanol-ethanol fermentation of corn stover: current production methods, economic viability and commercial use.

    PubMed

    Baral, Nawa R; Slutzky, Lauren; Shah, Ajay; Ezeji, Thaddeus C; Cornish, Katrina; Christy, Ann

    2016-03-01

    Biobutanol is a next-generation liquid biofuel with properties akin to those of gasoline. There is a widespread effort to commercialize biobutanol production from agricultural residues, such as corn stover, which do not compete with human and animal foods. This pursuit is backed by extensive government mandates to expand alternative energy sources. This review provides an overview of research on biobutanol production using corn stover feedstock. Structural composition, pretreatment, sugar yield (following pretreatment and hydrolysis) and generation of lignocellulose-derived microbial inhibitory compounds (LDMICs) from corn stover are discussed. The review also discusses different Clostridium species and strains employed for biobutanol production from corn stover-derived sugars with respect to solvent yields, tolerance to LDMICs and in situ solvent recovery (integrated fermentation). Further, the economics of cellulosic biobutanol production are highlighted and compared to corn starch-derived ethanol and gasoline. As discussed herein, the economic competitiveness of biobutanol production from corn stover largely depends on feedstock processing and fermentation process design.

  19. Models construction for acetone-butanol-ethanol fermentations with acetate/butyrate consecutively feeding by graph theory.

    PubMed

    Li, Zhigang; Shi, Zhongping; Li, Xin

    2014-05-01

    Several fermentations with consecutively feeding of acetate/butyrate were conducted in a 7 L fermentor and the results indicated that exogenous acetate/butyrate enhanced solvents productivities by 47.1% and 39.2% respectively, and changed butyrate/acetate ratios greatly. Then extracellular butyrate/acetate ratios were utilized for calculation of acids rates and the results revealed that acetate and butyrate formation pathways were almost blocked by corresponding acids feeding. In addition, models for acetate/butyrate feeding fermentations were constructed by graph theory based on calculation results and relevant reports. Solvents concentrations and butanol/acetone ratios of these fermentations were also calculated and the results of models calculation matched fermentation data accurately which demonstrated that models were constructed in a reasonable way.

  20. Saccharification of polysaccharide content of palm kernel cake using enzymatic catalysis for production of biobutanol in acetone-butanol-ethanol fermentation.

    PubMed

    Shukor, Hafiza; Abdeshahian, Peyman; Al-Shorgani, Najeeb Kaid Nasser; Hamid, Aidil Abdul; Rahman, Norliza A; Kalil, Mohd Sahaid

    2016-02-01

    In this work, hydrolysis of cellulose and hemicellulose content of palm kernel cake (PKC) by different types of hydrolytic enzymes was studied to evaluate monomeric sugars released for production of biobutanol by Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564) in acetone-butanol-ethanol (ABE) fermentation. Experimental results revealed that when PKC was hydrolyzed by mixed β-glucosidase, cellulase and mannanase, a total simple sugars of 87.81±4.78 g/L were produced, which resulted in 3.75±0.18 g/L butanol and 6.44±0.43 g/L ABE at 168 h fermentation. In order to increase saccharolytic efficiency of enzymatic treatment, PKC was pretreated by liquid hot water before performing enzymatic hydrolysis. Test results showed that total reducing sugars were enhanced to 97.81±1.29 g/L with elevated production of butanol and ABE up to 4.15±1.18 and 7.12±2.06 g/L, respectively which represented an A:B:E ratio of 7:11:1.

  1. Use of Proteomic Analysis To Elucidate the Role of Calcium in Acetone-Butanol-Ethanol Fermentation by Clostridium beijerinckii NCIMB 8052

    PubMed Central

    Han, Bei; Ujor, Victor; Lai, Lien B.; Gopalan, Venkat

    2013-01-01

    Calcium carbonate increases growth, substrate utilization, and acetone-butanol-ethanol (ABE) fermentation by Clostridium beijerinckii NCIMB 8052. Toward an understanding of the basis for these pleiotropic effects, we profiled changes in the C. beijerinckii NCIMB 8052 proteome that occur in response to the addition of CaCO3. We observed increases in the levels of different heat shock proteins (GrpE and DnaK), sugar transporters, and proteins involved in DNA synthesis, repair, recombination, and replication. We also noted significant decreases in the levels of proteins involved in metabolism, nucleic acid stabilization, sporulation, oxidative and antibiotic stress responses, and signal transduction. We determined that CaCO3 enhances ABE fermentation due to both its buffering effects and its ability to influence key cellular processes, such as sugar transport, butanol tolerance, and solventogenesis. Moreover, activity assays in vitro for select solventogenic enzymes revealed that part of the underpinning for the CaCO3-mediated increase in the level of ABE fermentation stems from the enhanced activity of these catalysts in the presence of Ca2+. Collectively, these proteomic and biochemical studies provide new insights into the multifactorial basis for the stimulation of ABE fermentation and butanol tolerance in the presence of CaCO3. PMID:23104411

  2. Integrative modelling of pH-dependent enzyme activity and transcriptomic regulation of the acetone-butanol-ethanol fermentation of Clostridium acetobutylicum in continuous culture.

    PubMed

    Millat, Thomas; Janssen, Holger; Bahl, Hubert; Fischer, Ralf-Jörg; Wolkenhauer, Olaf

    2013-09-01

    In a continuous culture under phosphate limitation the metabolism of Clostridium acetobutylicum depends on the external pH level. By comparing seven steady-state conditions between pH 5.7 and pH 4.5 we show that the switch from acidogenesis to solventogenesis occurs between pH 5.3 and pH 5.0 with an intermediate state at pH 5.1. Here, an integrative study is presented investigating how a changing external pH level affects the clostridial acetone-butanol-ethanol (ABE) fermentation pathway. This is of particular interest as the biotechnological production of n-butanol as biofuel has recently returned into the focus of industrial applications. One prerequisite is the furthering of the knowledge of the factors determining the solvent production and their integrative regulations. We have mathematically analysed the influence of pH-dependent specific enzyme activities of branch points of the metabolism on the product formation. This kinetic regulation was compared with transcriptomic regulation regarding gene transcription and the proteomic profile. Furthermore, both regulatory mechanisms were combined yielding a detailed projection of their individual and joint effects on the product formation. The resulting model represents an important platform for future developments of industrial butanol production based on C. acetobutylicum.

  3. Artificial symbiosis for acetone-butanol-ethanol (ABE) fermentation from alkali extracted deshelled corn cobs by co-culture of Clostridium beijerinckii and Clostridium cellulovorans

    PubMed Central

    2014-01-01

    Background Butanol is an industrial commodity and also considered to be a more promising gasoline substitute compared to ethanol. Renewed attention has been paid to solvents (acetone, butanol and ethanol) production from the renewable and inexpensive substrates, for example, lignocellulose, on account of the depletion of oil resources, increasing gasoline prices and deteriorating environment. Limited to current tools for genetic manipulation, it is difficult to develop a genetically engineered microorganism with combined ability of lignocellulose utilization and solvents production. Mixed culture of cellulolytic microorganisms and solventogenic bacteria provides a more convenient and feasible approach for ABE fermentation due to the potential for synergistic utilization of the metabolic pathways of two organisms. But few bacteria pairs succeeded in producing biobutanol of high titer or high productivity without adding butyrate. The aim of this work was to use Clostridium cellulovorans 743B to saccharify lignocellulose and produce butyric acid, instead of adding cellulase and butyric acid to the medium, so that the soluble sugars and butyric acid generated can be subsequently utilized by Clostridium beijerinckii NCIMB 8052 to produce butanol in one pot reaction. Results A stable artificial symbiotic system was constructed by co-culturing a celluloytic, anaerobic, butyrate-producing mesophile (C. cellulovorans 743B) and a non-celluloytic, solventogenic bacterium (C. beijerinckii NCIMB 8052) to produce solvents by consolidated bioprocessing (CBP) with alkali extracted deshelled corn cobs (AECC), a low-cost renewable feedstock, as the sole carbon source. Under optimized conditions, the co-culture degraded 68.6 g/L AECC and produced 11.8 g/L solvents (2.64 g/L acetone, 8.30 g/L butanol and 0.87 g/L ethanol) in less than 80 h. Besides, a real-time PCR assay based on the 16S rRNA gene sequence was performed to study the dynamics of the abundance of each strain

  4. Downstream process synthesis for biochemical production of butanol, ethanol, and acetone from grains: generation of optimal and near-optimal flowsheets with conventional operating units.

    PubMed

    Liu, Jiahong; Fan, L T; Seib, Paul; Friedler, Ferenc; Bertok, Botond

    2004-01-01

    Manufacturing butanol, ethanol, and acetone through grain fermentation has been attracting increasing research interest. In the production of these chemicals from fermentation, the cost of product recovery constitutes the major portion of the total production cost. Developing cost-effective flowsheets for the downstream processing is, therefore, crucial to enhancing the economic viability of this manufacturing method. The present work is concerned with the synthesis of such a process that minimizes the cost of the downstream processing. At the outset, a wide variety of processing equipment and unit operations, i.e., operating units, is selected for possible inclusion in the process. Subsequently, the exactly defined superstructure with minimal complexity, termed maximal structure, is constructed from these operating units with the rigorous and highly efficient graph-theoretic method for process synthesis based on process graphs (P-graphs). Finally, the optimal and near-optimal flowsheets in terms of cost are identified.

  5. Efficient carbon dioxide utilization and simultaneous hydrogen enrichment from off-gas of acetone-butanol-ethanol fermentation by succinic acid producing Escherichia coli.

    PubMed

    He, Aiyong; Kong, Xiangping; Wang, Chao; Wu, Hao; Jiang, Min; Ma, Jiangfeng; Ouyang, Pingkai

    2016-08-01

    The off-gas from acetone-butanol-ethanol (ABE) fermentation was firstly used to be CO2 source (co-substrate) for succinic acid production. The optimum ratio of H2/CO2 indicated higher CO2 partial pressures with presence of H2 could enhance C4 pathway flux and reductive product productivity. Moreover, when an inner recycling bioreactor was used for CO2 recycling at a high total pressure (0.2Mpa), a maximum succinic acid concentration of 65.7g·L(-1) was obtained, and a productivity of 0.76g·L(-1)·h(-1) and a high yield of 0.86g·g(-1) glucose were achieved. Furthermore, the hydrogen content was simultaneously enriched to 92.7%. These results showed one successful attempt to reuse the off-gas of ABE fermentation which can be an attractive CO2 source for succinic acid production.

  6. Acetone butanol ethanol (ABE) production from concentrated substrate: reduction in substrate inhibition by fed-batch technique and product inhibition by gas stripping.

    PubMed

    Ezeji, T C; Qureshi, N; Blaschek, H P

    2004-02-01

    Acetone butanol ethanol (ABE) was produced in an integrated fed-batch fermentation-gas stripping product-recovery system using Clostridium beijerinckii BA101, with H(2) and CO(2) as the carrier gases. This technique was applied in order to eliminate the substrate and product inhibition that normally restricts ABE production and sugar utilization to less than 20 g l(-1) and 60 g l(-1), respectively. In the integrated fed-batch fermentation and product recovery system, solvent productivities were improved to 400% of the control batch fermentation productivities. In a control batch reactor, the culture used 45.4 g glucose l(-1) and produced 17.6 g total solvents l(-1) (yield 0.39 g g(-1), productivity 0.29 g l(-1) h(-1)). Using the integrated fermentation-gas stripping product-recovery system with CO(2) and H(2) as carrier gases, we carried out fed-batch fermentation experiments and measured various characteristics of the fermentation, including ABE production, selectivity, yield and productivity. The fed-batch reactor was operated for 201 h. At the end of the fermentation, an unusually high concentration of total acids (8.5 g l(-1)) was observed. A total of 500 g glucose was used to produce 232.8 g solvents (77.7 g acetone, 151.7 g butanol, 3.4 g ethanol) in 1 l culture broth. The average solvent yield and productivity were 0.47 g g(-1) and 1.16 g l(-1) h(-1), respectively.

  7. Effect of dilute alkaline pretreatment on the conversion of different parts of corn stalk to fermentable sugars and its application in acetone-butanol-ethanol fermentation.

    PubMed

    Cai, Di; Li, Ping; Luo, Zhangfeng; Qin, Peiyong; Chen, Changjing; Wang, Yong; Wang, Zheng; Tan, Tianwei

    2016-07-01

    To investigate the effect of dilute alkaline pretreatment on different parts of biomass, corn stalk was separated into flower, leaf, cob, husk and stem, which were treated by NaOH in range of temperature and chemical loading. The NaOH-pretreated solid was then enzymatic hydrolysis and used as the substrate for batch acetone-butanol-ethanol (ABE) fermentation. The results demonstrated the five parts of corn stalk could be used as potential feedstock separately, with vivid performances in solvents production. Under the optimized conditions towards high product titer, 7.5g/L, 7.6g/L, 9.4g/L, 7g/L and 7.6g/L of butanol was obtained in the fermentation broth of flower, leaf, cob, husk and stem hydrolysate, respectively. Under the optimized conditions towards high product yield, 143.7g/kg, 126.3g/kg, 169.1g/kg, 107.7g/kg and 116.4g/kg of ABE solvent were generated, respectively.

  8. Co-fermentation of hemicellulose and starch from barley straw and grain for efficient pentoses utilization in acetone-butanol-ethanol production.

    PubMed

    Yang, Ming; Kuittinen, Suvi; Zhang, Junhua; Vepsäläinen, Jouko; Keinänen, Markku; Pappinen, Ari

    2015-03-01

    This study aims to efficiently use hemicellulose-based biomass for ABE (acetone-butanol-ethanol) production by co-fermentation with starch-based biomass. Two processes were investigated: (I) co-fermentation of sugars derived from hemicellulose and starch in a mixture of barley straw and grain that was pretreated with dilute acid; (II) co-fermentation of straw hemicellulosic hydrolysate and gelatinized grain slurry in which the straw was pretreated with dilute acid. The two processes produced 11.3 and 13.5 g/L ABE that contains 7.4 and 7.8 g/L butanol, respectively. In process I, pretreatment with 1.0% H2SO4 resulted in better ABE fermentability than with 1.5% H2SO4, but only 19% of pentoses were consumed. In process II, 95% of pentoses were utilized even in the hemicellulosic hydrolysate pretreated with more severe condition (1.5% H2SO4). The results suggest that process II is more favorable for hemicellulosic biomass utilization, and it is also attractive for sustainable biofuel production due to great biomass availability.

  9. Acetone-butanol-ethanol (ABE) fermentation using Clostridium acetobutylicum XY16 and in situ recovery by PDMS/ceramic composite membrane.

    PubMed

    Wu, Hao; Chen, Xiao-Peng; Liu, Gong-Ping; Jiang, Min; Guo, Ting; Jin, Wan-Qin; Wei, Ping; Zhu, Da-Wei

    2012-09-01

    PDMS/ceramic composite membrane was directly integrated with acetone-butanol-ethanol (ABE) fermentation using Clostridium acetobutylicum XY16 at 37 °C and in situ removing ABE from fermentation broth. The membrane was integrated with batch fermentation, and approximately 46 % solvent was extracted. The solvent in permeates was 118 g/L, and solvent productivity was 0.303 g/(L/h), which was approximately 33 % higher compared with the batch fermentation without in situ recovery. The fed-batch fermentation with in situ recovery by pervaporation continued for more than 200 h, 61 % solvent was extracted, and the solvent in penetration was 96.2 g/L. The total flux ranged from 0.338 to 0.847 kg/(m(2)/h) and the separation factor of butanol ranged from 5.1 to 27.1 in this process. The membrane was fouled by the active fermentation broth, nevertheless the separation performances were partially recovered by offline membrane cleaning, and the solvent productivity was increased to 0.252 g/(L/h), which was 19 % higher compared with that in situ recovery process without membrane cleaning.

  10. Enhanced sugar production from pretreated barley straw by additive xylanase and surfactants in enzymatic hydrolysis for acetone-butanol-ethanol fermentation.

    PubMed

    Yang, Ming; Zhang, Junhua; Kuittinen, Suvi; Vepsäläinen, Jouko; Soininen, Pasi; Keinänen, Markku; Pappinen, Ari

    2015-01-01

    This study aims to improve enzymatic sugar production from dilute sulfuric acid-pretreated barley straw for acetone-butanol-ethanol (ABE) fermentation. The effects of additive xylanase and surfactants (polyethylene glycol [PEG] and Tween) in an enzymatic reaction system on straw hydrolysis yields were investigated. By combined application of 2g/100g dry-matter (DM) xylanase and PEG 4000, the glucose yield was increased from 53.2% to 86.9% and the xylose yield was increased from 36.2% to 70.2%, which were considerably higher than results obtained with xylanase or surfactant alone. The ABE fermentation of enzymatic hydrolysate produced 10.8 g/L ABE, in which 7.9 g/L was butanol. The enhanced sugar production increased the ABE yield from 93.8 to 135.0 g/kg pretreated straw. The combined application of xylanase and surfactants has a large potential to improve sugar production from barley straw pretreated with a mild acid and that the hydrolysate showed good fermentability in ABE production.

  11. Improvement in the bioreactor specific productivity by coupling continuous reactor with repeated fed-batch reactor for acetone-butanol-ethanol production.

    PubMed

    Setlhaku, Mpho; Brunberg, Sina; Villa, Eva Del Amor; Wichmann, Rolf

    2012-10-15

    In comparison to the different fermentation modes for the production of acetone, butanol and ethanol (ABE) researched to date, the continuous fermentation is the most economically favored. Continuous fermentation with two or more reactor cascade is reported to be the most efficient as it results in a more stable solvent production process. In this work, it is shown that a continuous (first-stage) reactor coupled to a repeated fed-batch (second stage) is superior to batch and fed-batch fermentations, including two-stage continuous fermentation. This is due to the efficient catalyst use, reported through the specific product rate and rapid glucose consumption rate. High solvents are produced at 19.4 g(ABE) l⁻¹, with volumetric productivities of 0.92 g(butanol) l⁻¹ h⁻¹ and 1.47 g(ABE) l ⁻¹ h⁻¹. The bioreactor specific productivities of 0.62 and 0.39 g g⁻¹(cdw) h⁻¹ obtained show a high catalyst activity. This new process mode has not been reported before in the development of ABE fermentation and it shows great potential and superiority to the existing fermentation methods.

  12. Efficient butanol recovery from acetone-butanol-ethanol fermentation cultures grown on sweet sorghum juice by pervaporation using silicalite-1 membrane.

    PubMed

    Kanemoto, Miho; Negishi, Hideyuki; Sakaki, Keiji; Ikegami, Toru; Chohnan, Shigeru; Nitta, Youji; Kurusu, Yasurou; Ohta, Hiroyuki

    2016-06-01

    We investigated butanol recovery by pervaporation separation, using a silicalite-1 membrane, from batch cultures of butanol-producing Clostridium beijerinckii SBP2 grown on sweet sorghum juice as a fermentation medium. The pervaporation system yielded 73% (w/v) butanol from intact feed cultures containing 1% (w/v) butanol, and had a butanol permeation flux of 11 g m(-2) h(-1). Upon neutralization and activated charcoal treatment of the feed cultures, butanol yield and total flux increased to 82% (w/v) and 40 g m(-2) h(-1), respectively. This system is applicable to refining processes for practical biobutanol production from a promising energy crop, sweet sorghum.

  13. A novel process for direct production of acetone-butanol-ethanol from native starches using granular starch hydrolyzing enzyme by Clostridium saccharoperbutylacetonicum N1-4.

    PubMed

    Thang, Vu Hong; Kobayashi, Genta

    2014-02-01

    In this work, a new approach for acetone-butanol-ethanol (ABE) production has been proposed. Direct fermentation of native starches (uncooked process) was investigated by using granular starch hydrolyzing enzyme (GSHE) and Clostridium saccharoperbutylacetonicum N1-4. Even the process was carried out under suboptimal condition for activity of GSHE, the production of ABE was similar with that observed in conventional process or cooked process in terms of final solvent concentration (21.3 ± 0.4 to 22.4 ± 0.4 g/L), butanol concentration (17.5 ± 0.4 to 17.8 ± 0.3 g/L) and butanol yield (0.33 to 0.37 g/g). The production of solvents was significantly dependent on the source of starches. Among investigated starches, corn starch was more susceptible to GSHE while cassava starch was the most resistant to this enzyme. Fermentation using native corn starch resulted in the solvent productivity of 0.47 g/L h, which was about 15 % higher than that achieved in cooked process. On the contrary, uncooked process using cassava and wheat starch resulted in the solvent productivity of 0.30 and 0.37 g/L h, which were respectively about 30 % lower than those obtained in cooked process. No contamination was observed during all trials even fermentation media were prepared without sterilization. During the fermentation using native starches, no formation of foam is observed. This uncooked process does not require cooking starchy material; therefore, the thermal energy consumption for solvent production would remarkably be reduced in comparison with cooked process.

  14. Fermentation and genomic analysis of acetone-uncoupled butanol production by Clostridium tetanomorphum.

    PubMed

    Gong, Fuyu; Bao, Guanhui; Zhao, Chunhua; Zhang, Yanping; Li, Yin; Dong, Hongjun

    2016-02-01

    In typical acetone-butanol-ethanol (ABE) fermentation, acetone is the main by-product (50 % of butanol mass) of butanol production, resulting in a low yield of butanol. It is known that some Clostridium tetanomorphum strains are able to produce butanol without acetone in nature. Here, we described that C. tetanomorphum strain DSM665 can produce 4.16 g/L butanol and 4.98 g/L ethanol at pH 6.0, and 9.81 g/L butanol and 1.01 g/L ethanol when adding 1 mM methyl viologen. Butyrate and acetate could be reassimilated and no acetone was produced. Further analysis indicated that the activity of the acetate/butyrate:acetoacetyl-CoA transferase responsible for acetone production is lost in C. tetanomorphum DSM665. The genome of C. tetanomorphum DSM665 was sequenced and deposited in DDBJ, EMBL, and GenBank under the accession no. APJS00000000. Sequence analysis indicated that there are no typical genes (ctfA/B and adc) that are typically parts of an acetone synthesis pathway in C. tetanomorphum DSM665. This work provides new insights in the mechanism of clostridial butanol production and should prove useful for the design of a high-butanol-producing strain.

  15. Hybrid Vapor Stripping-Vapor Permeation Process for Recovery and Dehydration of 1-Butanol and Acetone/Butanol/Ethanol from Dilute Aqueous Solutions. Part 1. Process Simulations

    EPA Science Inventory

    BACKGROUND: Fermentative production of butanol is limited to low concentrations, typically less than 2 wt% solvent, due to product inhibition. The result is high separation energy demand by conventional distillation approaches, despite favorable vapor-liquid equilibrium and parti...

  16. Acetone-butanol Fermentation of Marine Macroalgae

    SciTech Connect

    Huesemann, Michael H.; Kuo, Li-Jung; Urquhart, Lindsay A.; Gill, Gary A.; Roesijadi, Guritno

    2012-03-01

    Mannitol and laminarin, which are present at high concentrations in the brown macroalga Saccharina spp., a type of kelp, are potential biochemical feedstocks for butanol production. To test their bioconversion potential, aqueous extracts of the kelp Saccharina spp., mannitol, and glucose (a product of laminarin hydrolysis) were subjected to acetone-butanol fermentation by Clostridium acetobutylicum (ATCC 824). Both mannitol and glucose were readily fermented. Mixed substrate fermentations with glucose and mannitol resulted in diauxic growth of C. acetobutylicum with glucose depletion preceding mannitol utilization. Fermentation of kelp extract exhibited triauxic growth, with an order of utilization of free glucose, mannitol, and bound glucose, presumably laminarin. The lag in laminarin utilization reflected the need for enzymatic hydrolysis of this polysaccharide into fermentable sugars. The butanol and total solvent yields were 0.12 g/g and 0.16 g/g, respectively, indicating that significant improvements are still needed to make industrial-scale acetone-butanol fermentations of seaweed economically feasible.

  17. Economic evaluation of the acetone - butanol fermentation

    SciTech Connect

    Lenz, T.G.; Morevra, A.R.

    1980-12-01

    The economics of producing acetone and 1-butanol via fermentation have been examined for a 45 X 10 to the power of 6 kg of solvents/year plant. For a molasses substrate, the total annual production costs were about $24.4 million vs. a total annual income of $36 million, with about $20 million total required capital. Molasses cost of about $24.4 million/year was critical to these economics. Liquid whey was next evaluated as an alternative feed. Whey feed saved about $11 million annually in feed costs and yielded about $7 million net additional annual revenues from protein sale. These primary differences gave an annual gross profit of about $15 million for the whey case and resulted in a discounted cash flow rate of return of 29%. It is concluded that waste based acetone-butanol production via fermentation deserves further attention in view of the attractive whey-based economics and the excellent potential of butanol as a fuel extender, especially for diesohol blending.

  18. Efficient acetone-butanol-ethanol production (ABE) by Clostridium acetobutylicum XY16 immobilized on chemically modified sugarcane bagasse.

    PubMed

    Kong, Xiangping; He, Aiyong; Zhao, Jie; Wu, Hao; Jiang, Min

    2015-07-01

    Sugarcane bagasse was chemically modified by polyethylenimine (PEI) and glutaraldehyde (GA) and then used as a support to immobilize Clostridium acetobutylicum XY16 in the process of butanol production. Compared with batch fermentation using unmodified sugarcane bagasse, 22.3 g/L total solvents were produced by cells immobilized on 4 g/L PEI treated sugarcane bagasse with high solvent productivity of 0.62 g/(L h) and glucose consumption rate of 1.67 g/(L h). Improvement of 14, 43, and 37 % in total solvent titer, solvent productivity and glucose consumption rate was observed, respectively. Enhanced solvent production of 25.14 g/L was obtained when using a high concentration of glucose of 80 g/L. Continuous fermentation was studied using PEI/GA modified sugarcane bagasse as immobilization support with a range of dilution which rates from 0.2 to 2.5 to find an optimal condition. The maximum solvent productivity of 11.32 g/(L h) was obtained at a high dilution rate of 2.0 h(-1).

  19. Increased productivity of Clostridium acetobutylicum fermentation of acetone, butanol, and ethanol by pervaporation through supported ionic liquid membrane.

    PubMed

    Izák, Pavel; Schwarz, Katrin; Ruth, Wolfgang; Bahl, Hubert; Kragl, Udo

    2008-03-01

    Pervaporation proved to be one of the best methods to remove solvents out of a solvent producing Clostridium acetobutylicum culture. By using an ionic liquid (IL)-polydimethylsiloxane (PDMS) ultrafiltration membrane (pore size 60 nm), we could guarantee high stability and selectivity during all measurements carried out at 37 degrees C. Overall solvent productivity of fermentation connected with continuous product removal by pervaporation was 2.34 g l(-1) h(-1). The supported ionic liquid membrane (SILM) was impregnated with 15 wt% of a novel ionic liquid (tetrapropylammonium tetracyano-borate) and 85 wt% of polydimethylsiloxane. Pervaporation, accomplished with the optimized SILM, led to stable and efficient removal of the solvents butan-1-ol and acetone out of a C. acetobutylicum culture. By pervaporation through SILM, we removed more butan-1-ol than C. acetobutylicum was able to produce. Therefore, we added an extra dose of butan-1-ol to run fermentation on limiting values where the bacteria would still be able to survive its lethal concentration (15.82 g/l). After pervaporation was switched off, the bacteria died from high concentration of butan-1-ol, which they produced.

  20. Reverse osmosis application for butanol-acetone fermentation

    SciTech Connect

    Garcia, A.; Iannotti, E.L.; Fischer, J.R.

    1984-01-01

    The problems of dilute solvent concentration in butanol-acetone fermentation can be solved by using reverse osmosis to dewater the fermentation liquor. Polyamide membranes exhibited butanol rejection rates as high as 85%. Optimum rejection of butanol occurs at a pressure of approximately 5.5 to 6.5 MPa and hydraulic recoveries of 50-70%. Flux ranged from 0.5 to 1.8 l.

  1. Microbiological production of acetone-butanol by Clostridium acetobutylicum.

    PubMed

    Abou-Zeid, A A; Fouad, M; Yassein, M

    1978-01-01

    Trials succeeded in raising the efficiencies of the fermentation medium, used in the fermentative production of acetone-butanol by Clostridium acetobutylicum. Egyptian black strap molasses (50.0% sugars) was suitable as carbon source in the fermentation medium, and (NH4)2SO4 was utilized with great success as inorganic nitrogen source. 140.0 g/l black strap molasses (about 7.0% sugars) and 3.0 g/l (NH4)2SO4 were the optimum concentrations for obtaining good yields of acetone and butanol. Molasses and (NH4)2SO4 were preferred because they are cheaper than the other carbon and organic nitrogen sources, used in the fermentative production of acetone-butanol. The percentage increase of the total solvents produced in the fermentation (production medium) was increased by 64.0. The slop (by-product of the acetone-butanol fermentation after distillation) was re-used in the fermentation medium as organic nitrogen source and supported the microorganisms for a good production of acetone and butanol, while when stillage was used in the production medium, the total solvents output was less than that produced in the medium containing slop.

  2. Characterization of a butanol-acetone-producing Clostridium strain and identification of its solventogenic genes.

    PubMed

    Chua, Teck Khiang; Liang, Da-Wei; Qi, Chao; Yang, Kun-Lin; He, Jianzhong

    2013-05-01

    A unique Clostridium species strain G117 was obtained in this study to be capable of producing dominant butanol from glucose. Butanol of 13.50 g/L was produced when culture G117 was fed with 60 g/L glucose, which is ~20% higher than previously reported butanol production by wild-type Clostridium acetobutylicum ATCC 824 under similar conditions. Strain G117 also distinguishes itself by generating negligible amount of ethanol, but producing butanol and acetone as biosolvent end-products. A butanol dehydrogenase gene (bdh gene) was identified in strain G117, which demonstrated a ~200-fold increase in transcription level measured by quantitative real-time PCR after 10h of culture growth. The high transcription suggests that this bdh gene could be a putative gene involved in butanol production. In all, Clostridium sp. strain G117 serves as a potential candidate for industrial biobutanol production while the absence of ethanol ensures an economic-efficient separation and purification of butanol.

  3. Acetone-Butanol-Ethanol (ABE) production in fermentation of enzymatically hydrolyzed cassava flour by Clostridium beijerinckii BA101 and solvent separation.

    PubMed

    Lépiz-Aguilar, Leonardo; Rodríguez-Rodríguez, Carlos E; Arias, María Laura; Lutz, Giselle

    2013-08-01

    Cassava constitutes an abundant substrate in tropical regions. The production of butanol in ABE fermentation by Clostridium beijerinckii BA101 using cassava flour (CF) was scaled-up to bioreactor level (5 L). Optimized fermentation conditions were applied; that is, 40℃, 60 g/l CF, and enzymatic pretreatment of the substrate. The batch fermentation profile presented an acidogenic phase for the first 24 h and a solventogenic phase afterwards. An average of 37.01 g/l ABE was produced after 83 h, with a productivity of 0.446 g/l/h. Butanol production was 25.71 g/l with a productivity of 0.310 g/l/h, high or similar to analogous batch processes described for other substrates. Solvent separation by different combinations of fractioned and azeotropic distillation and liquid-liquid separation were assessed to evaluate energetic and economic costs in downstream processing. Results suggest that the use of cassava as a substrate in ABE fermentation could be a cost-effective way of producing butanol in tropical regions.

  4. Effect of ozonolysis parameters on the inhibitory compound generation and on the production of ethanol by Pichia stipitis and acetone-butanol-ethanol by Clostridium from ozonated and water washed sugarcane bagasse.

    PubMed

    Travaini, Rodolfo; Barrado, Enrique; Bolado-Rodríguez, Silvia

    2016-10-01

    Sugarcane bagasse (SCB) was ozone pretreated and detoxified by water washing, applying a L9(3)(4) orthogonal array (OA) design of experiments to study the effect of pretreatment parameters (moisture content, ozone concentration, ozone/oxygen flow and particle size) on the generation of inhibitory compounds and on the composition of hydrolysates of ozonated-washed samples. Ozone concentration resulted the highest influence process parameter on delignification and sugar release after washing; while, for inhibitory compound formation, moisture content also had an important role. Ozone expended in pretreatment related directly with sugar release and inhibitory compound formation. Washing detoxification was effective, providing non-inhibitory hydrolysates. Maximum glucose and xylose release yields obtained were 84% and 67%, respectively, for ozonated-washed SCB. Sugar concentration resulted in the decisive factor for biofuels yields. Ethanol production achieved an 88% yield by Pichia stipitis, whereas Clostridium acetobutylicum produced 0.072gBUTANOL/gSUGAR and 0.188gABE/gSUGAR, and, Clostridium beijerinckii 0.165gBUTANOL/gSUGAR and 0.257gABE/gSUGAR.

  5. Global transcriptional changes of Clostridium acetobutylicum cultures with increased butanol:acetone ratios.

    PubMed

    Hönicke, Daniel; Janssen, Holger; Grimmler, Christina; Ehrenreich, Armin; Lütke-Eversloh, Tina

    2012-05-15

    Artificial electron carriers have been widely used to shift the solvent ratio toward butanol in acetone-butanol-ethanol (ABE) fermentation of solventogenic clostridia according to decreased hydrogen production. In this study, first insights on the molecular level were gained to explore the effect of methyl viologen addition to cultures of Clostridium acetobutylicum. Employing batch fermentation in mineral salts medium, the butanol:acetone ratio was successively increased from 2.3 to 12.4 on a 100-ml scale in serum bottles and from 1.4 to 16.5 on a 1300-ml scale in bioreactors, respectively. The latter cultures were used for DNA microarray analyses to provide new information on the transcriptional changes referring to methyl viologen exposure and thus, exhibit gene expression patterns according to the manipulation of the cellular redox balance. Methyl viologen-exposed cultures revealed lower expression levels of the sol operon (CAP0162-0164) and the adjacent adc gene (CAP0165) responsible for solvent formation as well as iron and sulfate transporters and the CAC0105-encoded ferredoxin. On the contrary, genes for riboflavin biosynthesis, for the butyrate/butanol metabolic pathway and genes coding for sugar transport systems were induced. Interestingly, the adhE2-encoded bifunctional NADH-dependent aldhehyde/alcohol-dehydrogenase (CAP0035) was upregulated up to more than 100-fold expression levels as compared to the control culture without methyl viologen addition. The data presented here indicate a transcriptional regulation for decreased acetone biosynthesis and the redox-dependent substitution of adhE1 (CAP0162) by adhE2.

  6. Technical and economic assessment of processes for the production of butanol and acetone

    NASA Technical Reports Server (NTRS)

    1982-01-01

    This report represents a preliminary technical and economic evaluation of a process which produces mixed solvents (butaol/acetone/ethanol) via fermentation of sugars derived from renewable biomass resources. The objective is to assess the technology of producing butanol/acetone from biomass, and select a viable process capable of serving as a base case model for technical and economic analysis. It is anticipated that the base case process developed herein can then be used as the basis for subsequent studies concerning biomass conversion processes capable of producing a wide range of chemicals. The general criteria utilized in determining the design basis for the process are profit potential and non-renewable energy displacement potential. The feedstock chosen, aspen wood, was selected from a number of potential renewable biomass resources as the most readily available in the United States and for its relatively large potential for producing reducing sugars.

  7. Enzymology of acetone-butanol-isopropanol formation. Progress report, January 1, 1991--December 31, 1991

    SciTech Connect

    Chen, Jiann-Shin

    1992-01-01

    The long-term goal of the project is to understand the fundamental properties of biological solvent production. Our approach is to elucidate first the molecular properties of solvent-producing enzymes and then to apply to information gained from the enzymological study to investigate control mechanisms for the solvent-producing pathways and the expression of solvent-production genes. Our research primarily involves two strains of Clostridium beijerinckii: C. Beijerinckii NRRL B593 which produces isopropanol in addition to acetone, butanol, and ethanol, and C. beijerinckii NRRL B592 which produces acetone, butanol and ethanol, but not isopropanol. In more recent studies, we also included another solvent-producing organism, Bacillus macerans. Objectives for the reporting period were: to characterize the distinct types of alcohol dehydrogenase; to purify and characterize acetoacetyl-CoA-reacting enzymes; and to clone and sequence the gene encoding the primary/secondary alcohol dehydrogenase of C beijerinckii NRRL B593 and to search for the promoter region for solvent-production genes.

  8. Industrial production of acetone and butanol by fermentation—100 years later

    PubMed Central

    Sauer, Michael

    2016-01-01

    Microbial production of acetone and butanol was one of the first large-scale industrial fermentation processes of global importance. During the first part of the 20th century, it was indeed the second largest fermentation process, superseded in importance only by the ethanol fermentation. After a rapid decline after the 1950s, acetone-butanol-ethanol (ABE) fermentation has recently gained renewed interest in the context of biorefinery approaches for the production of fuels and chemicals from renewable resources. The availability of new methods and knowledge opens many new doors for industrial microbiology, and a comprehensive view on this process is worthwhile due to the new interest. This thematic issue of FEMS Microbiology Letters, dedicated to the 100th anniversary of the first industrial exploitation of Chaim Weizmann's ABE fermentation process, covers the main aspects of old and new developments, thereby outlining a model development in biotechnology. All major aspects of industrial microbiology are exemplified by this single process. This includes new technologies, such as the latest developments in metabolic engineering, the exploitation of biodiversity and discoveries of new regulatory systems such as for microbial stress tolerance, as well as technological aspects, such as bio- and down-stream processing. PMID:27199350

  9. Improvement of the butanol production selectivity and butanol to acetone ratio (B:A) by addition of electron carriers in the batch culture of a new local isolate of Clostridium acetobutylicum YM1.

    PubMed

    Nasser Al-Shorgani, Najeeb Kaid; Kalil, Mohd Sahaid; Wan Yusoff, Wan Mohtar; Shukor, Hafiza; Hamid, Aidil Abdul

    2015-12-01

    Improvement in the butanol production selectivity or enhanced butanol:acetone ratio (B:A) is desirable in acetone-butanol-ethanol (ABE) fermentation by Clostridium strains. In this study, artificial electron carriers were added to the fermentation medium of a new isolate of Clostridium acetobutylicum YM1 in order to improve the butanol yield and B:A ratio. The results revealed that medium supplementation with electron carriers changed the metabolism flux of electron and carbon in ABE fermentation by YM1. A decrease in acetone production, which subsequently improved the B:A ratio, was observed. Further improvement in the butanol production and B:A ratios were obtained when the fermentation medium was supplemented with butyric acid. The maximum butanol production (18.20 ± 1.38 g/L) was gained when a combination of methyl red and butyric acid was added. Although the addition of benzyl viologen (0.1 mM) and butyric acid resulted in high a B:A ratio of 16:1 (800% increment compared with the conventional 2:1 ratio), the addition of benzyl viologen to the culture after 4 h resulted in the production of 18.05 g/L butanol. Manipulating the metabolic flux to butanol through the addition of electron carriers could become an alternative strategy to achieve higher butanol productivity and improve the B:A ratio.

  10. Catalytic Combustion of Ethanol and Butanol

    DTIC Science & Technology

    2009-09-01

    completely for thermoelectric applications, or operate as a fuel reformer to produce hydrogen gas for fuel cells. 15. SUBJECT TERMS Alcohol, butanol...Hydrogen selectivity data for ethanol combustion is depicted in figure 10 as a function of equivalence ratio. Data for hydrogen gas , water vapor...further, more carbon monoxide, methane , and even ethene are produced as the carbon selectivity of carbon dioxide decreases. The appearance of

  11. Carbon monoxide bioconversion to butanol-ethanol by Clostridium carboxidivorans: kinetics and toxicity of alcohols.

    PubMed

    Fernández-Naveira, Ánxela; Abubackar, Haris Nalakath; Veiga, María C; Kennes, Christian

    2016-05-01

    Butanol production from carbon monoxide-rich waste gases or syngas is an attractive novel alternative to the conventional acetone-butanol-ethanol (ABE) fermentation. Solvent toxicity is a key factor reported in ABE fermentation with carbohydrates as substrates. However, in the gas-fermentation process, kinetic aspects and the inhibition effect of solvents have not thoroughly been studied. Therefore, different batch bottle experiments were carried out with the bacterial species Clostridium carboxidivorans using CO as carbon source for butanol-ethanol fermentation. A maximum specific growth rate of 0.086 ± 0.004 h(-1) and a biomass yield of 0.011 gbiomass/gCO were found, which is significantly lower than in other clostridia grown on sugars. Besides, three assays were carried out to check the inhibitory effect of butanol, ethanol, and their mixtures. Butanol had a higher inhibitory effect on the cells than ethanol and showed a lower IC50, reduced growth rate, and slower CO consumption with increasing alcohol concentrations. A concentration of 14-14.50 g/L butanol caused 50 % growth inhibition in C. carboxidivorans, and 20 g/L butanol resulted in complete inhibition, with a growth rate of 0 h(-1). Conversely, 35 g/L ethanol decreased by 50 % the final biomass concentration respect to the control and yielded the lowest growth rate of 0.024 h(-1). The inhibitory effect of mixtures of both alcohols was also checked adding similar, near identical, concentrations of each one. Growth decreased by 50 % in the presence of a total concentration of alcohols of 16.22 g/L, consisting of similar amounts of each alcohol. Occasional differences in initially added concentrations of alcohols were minimal. The lowest growth rate (0.014 h(-1)) was observed at the highest concentration assayed (25 g/L).

  12. Acetone, butanol, and ethanol production from cane molasses using Clostridium beijerinckii mutant obtained by combined low-energy ion beam implantation and N-methyl-N-nitro-N-nitrosoguanidine induction.

    PubMed

    Li, Han-guang; Luo, Wei; Gu, Qiu-ya; Wang, Qiang; Hu, Wen-jun; Yu, Xiao-bin

    2013-06-01

    In order to obtain mutant strains showing higher solvent tolerance and butanol production than those of wild-type strains, the butanol-producing strain Clostridium beijerinckii L175 was subjected to mutagenesis using a combined method of low-energy ion beam implantation and N-methyl-N-nitro-N-nitrosoguanidine induction. With this effort, mutant strain MUT3 was isolated. When it was used for butanol fermentation in P2 medium, the production of butanol was 15.8±0.7 g/L 46% higher than the wild-type strain. Furthermore, after optimization of butanol production from cane molasses with MUT3, the maximum butanol production of 14.9±0.5 g/L were obtained in crew-capped bottles. When ABE production by MUT3 was carried out in a bioreactor, the production of butanol and total solvent were 15.1±0.8 g/L and 22.1±0.9 g/L, respectively. The remarkable butanol production and solvent tolerance of MUT3 make it promising for butanol production from cane molasses.

  13. Metabolic Engineering of Clostridium acetobutylicum ATCC 824 for Isopropanol-Butanol-Ethanol Fermentation

    PubMed Central

    Lee, Joungmin; Jang, Yu-Sin; Choi, Sung Jun; Im, Jung Ae; Song, Hyohak; Cho, Jung Hee; Seung, Do Young; Papoutsakis, E. Terry; Bennett, George N.

    2012-01-01

    Clostridium acetobutylicum naturally produces acetone as well as butanol and ethanol. Since acetone cannot be used as a biofuel, its production needs to be minimized or suppressed by cell or bioreactor engineering. Thus, there have been attempts to disrupt or inactivate the acetone formation pathway. Here we present another approach, namely, converting acetone to isopropanol by metabolic engineering. Since isopropanol can be used as a fuel additive, the mixture of isopropanol, butanol, and ethanol (IBE) produced by engineered C. acetobutylicum can be directly used as a biofuel. IBE production is achieved by the expression of a primary/secondary alcohol dehydrogenase gene from Clostridium beijerinckii NRRL B-593 (i.e., adhB-593) in C. acetobutylicum ATCC 824. To increase the total alcohol titer, a synthetic acetone operon (act operon; adc-ctfA-ctfB) was constructed and expressed to increase the flux toward isopropanol formation. When this engineering strategy was applied to the PJC4BK strain lacking in the buk gene (encoding butyrate kinase), a significantly higher titer and yield of IBE could be achieved. The resulting PJC4BK(pIPA3-Cm2) strain produced 20.4 g/liter of total alcohol. Fermentation could be prolonged by in situ removal of solvents by gas stripping, and 35.6 g/liter of the IBE mixture could be produced in 45 h. PMID:22210214

  14. Metabolic engineering of Clostridium acetobutylicum for the enhanced production of isopropanol-butanol-ethanol fuel mixture.

    PubMed

    Jang, Yu-Sin; Malaviya, Alok; Lee, Joungmin; Im, Jung Ae; Lee, Sang Yup; Lee, Julia; Eom, Moon-Ho; Cho, Jung-Hee; Seung, Do Young

    2013-01-01

    Butanol is considered as a superior biofuel, which is conventionally produced by clostridial acetone-butanol-ethanol (ABE) fermentation. Among ABE, only butanol and ethanol can be used as fuel alternatives. Coproduction of acetone thus causes lower yield of fuel alcohols. Thus, this study aimed at developing an improved Clostridium acetobutylicum strain possessing enhanced fuel alcohol production capability. For this, we previously developed a hyper ABE producing BKM19 strain was further engineered to convert acetone into isopropanol. The BKM19 strain was transformed with the plasmid pIPA100 containing the sadh (primary/secondary alcohol dehydrogenase) and hydG (putative electron transfer protein) genes from the Clostridium beijerinckii NRRL B593 cloned under the control of the thiolase promoter. The resulting BKM19 (pIPA100) strain produced 27.9 g/l isopropanol-butanol-ethanol (IBE) as a fuel alcohols with negligible amount of acetone (0.4 g/l) from 97.8 g/l glucose in lab-scale (2 l) batch fermentation. Thus, this metabolically engineered strain was able to produce 99% of total solvent produced as fuel alcohols. The scalability and stability of BKM19 (pIPA100) were evaluated at 200 l pilot-scale fermentation, which showed that the fuel alcohol yield could be improved to 0.37 g/g as compared to 0.29 g/g obtained at lab-scale fermentation, while attaining a similar titer. To the best of our knowledge, this is the highest titer of IBE achieved and the first report on the large scale fermentation of C. acetobutylicum for IBE production.

  15. Infrared spectroscopic investigations of cationic ethanol, propanol, and butanol

    NASA Astrophysics Data System (ADS)

    Matsuda, Yoshiyuki; Harigaya, Hiroyuki; Xie, Min; Takahashi, Kaito; Fujii, Asuka

    2015-11-01

    Infrared spectroscopy of the alcohol cations of ethanol, propanol, and butanol was performed to investigate their structures and hyperconjugation mechanisms. In the ethanol cation, the Csbnd C bond hyperconjugates with the singly occupied molecular orbital (SOMO) at the oxygen atom, so that the Csbnd C bond weakens and the bond length elongates. Multiple hyperconjugations among SOMO, the Csbnd C bond, and the end Csbnd H bond occur in the propanol cation and enhance the acidity of the Csbnd H bond through the delocalization of its bonding σ electron. The butanol cation forms the oxonium-type structure through the proton transfer from the terminal CH bond.

  16. Pervaporation of ethanol and acetone above normal boiling temperatures

    SciTech Connect

    Windmoeller, D.; Galembeck, F. )

    1992-08-01

    Pervaporation experiments were performed at higher than normal feed liquid boiling temperatures by applying pressure to the feed compartment. Ethanol, acetone, and aqueous ethanol solutions were pervaporated through silicone rubber dense membranes. Large increases were observed in the permeate flow as the temperature rose above the liquid boiling temperature. Separation factors in aqueous ethanol pervaporation are not affected by these increases in permeate output, and they are in the same range as those obtained in conventional pervaporation.

  17. Molecular interaction forces in acetone + ethanol binary liquid solutions: FTIR and theoretical studies

    NASA Astrophysics Data System (ADS)

    Jadhav, Deepali L.; Karthick, N. K.; Kannan, P. P.; Shanmugam, R.; Elangovan, A.; Arivazhagan, G.

    2017-02-01

    FTIR spectra of neat acetone, ethanol and their binary solutions at the molar ratios 0.2:0.8 (ethanol: acetone), 0.4:0.6, 0.6:0.4 and 0.8:0.2 have been recorded at room temperature. Theoretical calculations have also been made on acetone (monomer and dimer), ethanol monomer, dimer, trimer, tetramer, pentamer, hexamer and ethanol - acetone complex molecules. 4:1 (ethanol:acetone), 5:1 and 6:2 complexation through the classical Cdbnd O⋯Hsbnd O and (acetone) Csbnd H⋯Osbnd C(ethanol) hydrogen bonds has been identified. Ethanol rich solutions may consist of ethanol multimers such as tetramer, pentamer and hexamer along with 4:1, 5:1 and 6:2 complex molecules depending upon ethanol concentration. Acetone seems to exist as a mixture of monomer and dimer.

  18. Butanol production by fermentation: efficient bioreactors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy security, environmental concerns, and business opportunities in the emerging bio-economy have generated strong interest in the production of n-butanol by fermentation. Acetone butanol ethanol (ABE or solvent) batch fermentation process is product limiting because butanol even at low concentra...

  19. Increasing butanol/acetone ratio and solvent productivity in ABE fermentation by consecutively feeding butyrate to weaken metabolic strength of butyrate loop.

    PubMed

    Li, Xin; Shi, Zhongping; Li, Zhigang

    2014-08-01

    In this study, we attempted to increase butanol/acetone ratio and total solvent productivity in ABE fermentations with corn- and cassava-based media, by consecutively feeding a small amount of butyrate/acetate during solventogenic phase to weaken the metabolic strengths in butyrate/acetate closed-loops. Consecutively feeding a small amount of butyrate (a total of 3.0 g/L-broth) is most effective in improving performance of corn-based ABE fermentations, as it simultaneously increased average butanol/acetone ratio by 23 % (1.92-2.36) and total solvent productivity by 16 % (0.355-0.410 g/L/h) as compared with those of control. However, the butyrate feeding strategy could not improve butanol/acetone ratio and total solvent productivity in cassava-based ABE fermentations, where the metabolic strength of butyrate closed-loop had already been very low.

  20. Elucidating the contributions of multiple aldehyde/alcohol dehydrogenases to butanol and ethanol production in Clostridium acetobutylicum

    PubMed Central

    Dai, Zongjie; Dong, Hongjun; Zhang, Yanping; Li, Yin

    2016-01-01

    Ethanol and butanol biosynthesis in Clostridium acetobutylicum share common aldehyde/alcohol dehydrogenases. However, little is known about the relative contributions of these multiple dehydrogenases to ethanol and butanol production respectively. The contributions of six aldehyde/alcohol dehydrogenases of C. acetobutylicum on butanol and ethanol production were evaluated through inactivation of the corresponding genes respectively. For butanol production, the relative contributions from these enzymes were: AdhE1 > BdhB > BdhA ≈ YqhD > SMB_P058 > AdhE2. For ethanol production, the contributions were: AdhE1 > BdhB > YqhD > SMB_P058 > AdhE2 > BdhA. AdhE1 and BdhB are two essential enzymes for butanol and ethanol production. AdhE1 was relatively specific for butanol production over ethanol, while BdhB, YqhD, and SMB_P058 favor ethanol production over butanol. Butanol synthesis was increased in the adhE2 mutant, which had a higher butanol/ethanol ratio (8.15:1) compared with wild type strain (6.65:1). Both the SMB_P058 mutant and yqhD mutant produced less ethanol without loss of butanol formation, which led to higher butanol/ethanol ratio, 10.12:1 and 10.17:1, respectively. To engineer a more efficient butanol-producing strain, adhE1 could be overexpressed, furthermore, adhE2, SMB_P058, yqhD are promising gene inactivation targets. This work provides useful information guiding future strain improvement for butanol production. PMID:27321949

  1. [Acetone-butanol fermentation from the mixture of fructose and glucose].

    PubMed

    Deng, Pan; Chen, Lijie; Xin, Chengxun; Bai, Fengwu

    2011-10-01

    A mixture of fructose and glucose was developed to simulate the hydrolysate of Jerusalem artichoke tubers, the fructose-based feedstock suitable for butanol production. With the initial pH of 5.5 without regulation during mixed-sugar fermentation, as high as 23.26 g/L sugars were remained unconverted, and butanol production of 5.51 g/L were obtained. Compared with either glucose or fructose fermentation, the early termination of mixed-sugar fermentation might be caused by toxic organic acids and the low pH. When the pH of the fermentation system was controlled at higher levels, it was found that sugars utilization was facilitated, but less butanol was produced due to the over-accumulation of organic acids. On the other hand, when the pH was controlled at lower levels, more sugars were remained unconverted, although butanol production was improved. Based on these experimental results, a stage-wise pH regulation strategy, e.g., controlling the pH of the fermentation system at 5.5 untill the OD620 reached 1.0, and then the pH control was removed, was developed, which significantly improved the fermentation performance of the system, with only 2.05 g/L sugars unconverted and 10.48 g/L butanol produced.

  2. Characterization of an Arxula adeninivorans alcohol dehydrogenase involved in the metabolism of ethanol and 1-butanol.

    PubMed

    Kasprzak, Jakub; Rauter, Marion; Riechen, Jan; Worch, Sebastian; Baronian, Kim; Bode, Rüdiger; Schauer, Frieder; Kunze, Gotthard

    2016-05-01

    In this study, alcohol dehydrogenase 1 from Arxula adeninivorans (Aadh1p) was identified and characterized. Aadh1p showed activity with short and medium chain length primary alcohols in the forward reaction and their aldehydes in the reverse reaction. Aadh1p has 64% identity with Saccharomyces cerevisiae Adh1p, is localized in the cytoplasm and uses NAD(+) as cofactor. Gene expression analysis showed a low level increase in AADH1 gene expression with ethanol, pyruvate or xylose as the carbon source. Deletion of the AADH1 gene affects growth of the cells with 1-butanol, ethanol and glucose as the carbon source, and a strain which overexpressed the AADH1 gene metabolized 1-butanol more rapidly. An ADH activity assay indicated that Aadh1p is a major enzyme for the synthesis of ethanol and the degradation of 1-butanol in A. adeninivorans.

  3. Efficient butanol-ethanol (B-E) production from carbon monoxide fermentation by Clostridium carboxidivorans.

    PubMed

    Fernández-Naveira, Ánxela; Abubackar, Haris Nalakath; Veiga, María C; Kennes, Christian

    2016-04-01

    The fermentation of waste gases rich in carbon monoxide using acetogens is an efficient way to obtain valuable biofuels like ethanol and butanol. Different experiments were carried out with the bacterial species Clostridium carboxidivorans as biocatalyst. In batch assays with no pH regulation, after complete substrate exhaustion, acetic acid, butyric acid, and ethanol were detected while only negligible butanol production was observed. On the other side, in bioreactors, with continuous carbon monoxide supply and pH regulation, both C2 and C4 fatty acids were initially formed as well as ethanol and butanol at concentrations never reported before for this type of anaerobic bioconversion of gaseous C1 compounds, showing that the operating conditions significantly affect the metabolic fermentation profile and butanol accumulation. Maximum ethanol and butanol concentrations in the bioreactors were obtained at pH 5.75, reaching values of 5.55 and 2.66 g/L, respectively. The alcohols were produced both from CO fermentation as well as from the bioconversion of previously accumulated acetic and butyric acids, resulting in low residual concentrations of such acids at the end of the bioreactor experiments. CO consumption was often around 50% and reached up to more than 80%. Maximum specific rates of ethanol and butanol production were reached at pH 4.75, with values of 0.16 g/h*g of biomass and 0.07 g/h*g of biomass, respectively, demonstrating that a low pH was more favorable to solventogenesis in this process, although it negatively affects biomass growth which does also play a role in the final alcohol titer.

  4. Acetone

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 03 / 004 www.epa.gov / iris TOXICOLOGICAL REVIEW OF ACETONE ( CAS No . 67 - 64 - 1 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) May 2003 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been reviewed in accor

  5. Investigation of acetone, butanol and carbon dioxide as new breath biomarkers for convenient and noninvasive diagnosis of obstructive sleep apnea syndrome.

    PubMed

    Bayrakli, Ismail; Öztürk, Önder; Akman, Hatice

    2016-12-01

    The objective of the present study was to investigate whether analysis of carbon dioxide, acetone and/or butanol present in human breath can be used as a simple and noninvasive diagnosis method for obstructive sleep apnea syndrome (OSAS). For this purpose, overnight changes in the concentrations of these breath molecules were measured before and after sleep in 10 patients who underwent polysomnography and were diagnosed with OSAS, and were compared with the levels of these biomarkers determined after sleep in 10 healthy subjects. The concentrations of exhaled carbon dioxide were measured using external cavity laser-based off-axis cavity enhanced absorption spectroscopy, whereas the levels of exhaled acetone and butanol were determined using thermal desorption gas chromatography mass spectrometry. We observed no significant changes in the levels of exhaled acetone and carbon dioxide in OSAS patients after sleep compared with pre-sleep values and compared with those in healthy control subjects. However, for the first time, to our knowledge, analyses of expired air showed an increased concentration of butanol after sleep compared with that before sleep and compared with that in healthy subjects. These results suggest that butanol can be established as a potential biomarker to enable the convenient and noninvasive diagnosis of OSAS in the future.

  6. The mechanism of switching from an acidogenic to butanol-acetone fermentation by Clostridium acetobutylicum

    SciTech Connect

    Rogers, P.

    1992-01-01

    The overall objective of this project is to elucidate the detailed mechanism by which solvent-forming bacteria such as Clostridium acetobutylicum regulate the well-known shift in fermentation pathway between alcohol-acetone and organic acid production. It is desired to eventually isolate and describe: (1) the regulatory genes and protein elements that determine induction of synthesis of the solvent-pathway enzymes; and (2) how this regulation system interacts with the sporulatin induction and development program and with related pathways such as granulse and exopolysaccharide formation in clostridia. A working model forhow clostridial control systems work can be derived from recent research on stress systems in E. coli and sporulation in Bacillus subtilis.

  7. Alcaligenes faecalis subsp. parafaecalis subsp. nov., a bacterium accumulating poly-beta-hydroxybutyrate from acetone-butanol bioprocess residues.

    PubMed

    Schroll, G; Busse, H J; Parrer, G; Rölleke, S; Lubitz, W; Denner, E B

    2001-04-01

    The authors have previously isolated a solvent tolerant bacterium, strain G(T), (T = type strain) capable to convert acetone-butanol bioprocess residues into poly-beta-hydroxybutyrate. Strain G(T) was initially identified as Alcaligenes spp by standard bacteriological tests. In this study the taxonomic position of the bacterium was investigated in detail. The 165 rDNA sequence analysis, the G + C content of DNA (56 mol%) and the presence of ubiquinone Q-8 confirmed strain G(T) as a representative of the genus Alcaligenes. In the polyamine pattern of the bacterium putrescine and cadaverine were detected, but only trace amounts of 2-hydroxyputrescine. The extremely low content of 2-hydroxyputrescine is remarkable, since this unique diamine is a common marker for beta-proteobacteria. Phylogenetic analyses of 16S rDNA demonstrated that Alcaligenes sp. G(T) is most closely related to the species Alcaligenes faecalis (99.6% sequence similarity to A. faecalis HR4 and 98.7% sequence similarity to A. faecalis [ATCC 8750T = DSM 30030T]. On the basis of DNA-DNA relatedness (56% similarity), the unique polyamine pattern, the physiological and biochemical differences strain G(T) could be distinguished from the species A. faecalis. Therefore, a new subspecies for the species Alcaligenes faecalis is proposed; Alcaligenes faecalis subsp. parafaecalis subsp. nov.

  8. Cellulosic butanol biofuel production from sweet sorghum bagasse (SSB): Impact of hot water pretreatment and solid loadings on fermentation employing Clostridium beijerinckii P260

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel butanol fermentation process was developed in which sweet sorghum bagasse (SSB) was pretreated using liquid hot water (LHW) pretreatment technique followed by enzymatic hydrolysis and butanol (acetone butanol ethanol; ABE) fermentation. A pretreatment temperature of 200 deg C resulted in the...

  9. Performance comparison of ethanol and butanol production in a continuous and closed-circulating fermentation system with membrane bioreactor.

    PubMed

    Chen, Chunyan; Long, Sihua; Li, Airong; Xiao, Guoqing; Wang, Linyuan; Xiao, Zeyi

    2017-03-16

    Since both ethanol and butanol fermentations are urgently developed processes with the biofuel-demand increasing, performance comparison of aerobic ethanol fermentation and anerobic butanol fermentation in a continuous and closed-circulating fermentation (CCCF) system was necessary to achieve their fermentation characteristics and further optimize the fermentation process. Fermentation and pervaporation parameters including the average cell concentration, glucose consumption rate, cumulated production concentration, product flux, and separation factor of ethanol fermentation were 11.45 g/L, 3.70 g/L/h, 655.83 g/L, 378.5 g/m(2)/h, and 4.83, respectively, the corresponding parameters of butanol fermentation were 2.19 g/L, 0.61 g/L/h, 28.03 g/L, 58.56 g/m(2)/h, and 10.62, respectively. Profiles of fermentation and pervaporation parameters indicated that the intensity and efficiency of ethanol fermentation was higher than butanol fermentation, but the stability of butanol fermentation was superior to ethanol fermentation. Although the two fermentation processes had different features, the performance indicated the application prospect of both ethanol and butanol production by the CCCF system.

  10. The post-mortem relationship between beta-hydroxybutyrate (BHB), acetone and ethanol in ketoacidosis.

    PubMed

    Elliott, Simon; Smith, Christopher; Cassidy, Diane

    2010-05-20

    A reduced blood pH (ketoacidosis) from the production of beta-oxidative ketone bodies as a result of alcoholism (alcoholic ketoacidosis, AKA) or diabetes (diabetic ketoacidosis, DKA) can feature in many fatalities and analytical evidence can be used to support a pathological diagnosis, or provide a possible cause of death in the absence of other pathologically significant findings. Existing beliefs concerning the relationship of BHB concentrations, acetone and ethanol have been re-examined by analysis of BHB, acetone and ethanol in over 350 fatalities grouped into alcoholics, diabetics, alcoholic diabetics, coupled with speculative cases and those with an alternative cause of death. Uniquely, the concentrations of BHB were measured in post-mortem blood, urine and vitreous humour using selective GC-MS. The results showed that existing beliefs need to be re-evaluated. Ethanol is not always low (<10mg/dL) or absent in cases of AKA. Also, the absence of acetone precludes [corrected] a high BHB (>250mg/L), therefore acetone can be used as an initial marker pathologically significant ketoacidosis. For blood and urine BHB concentrations the following interpretative ranges can be used (in mg/L); normal (<50mg/L), raised (51-249mg/L), high and pathologically significant (>250mg/L). Initial data suggest vitreous humour BHB could be a useful alternative in the absence of blood (same interpretative ranges may also apply). Analytical recommendation for investigation of post-mortem ketoacidosis is also presented.

  11. Problems with the microbial production of butanol.

    PubMed

    Zheng, Yan-Ning; Li, Liang-Zhi; Xian, Mo; Ma, Yu-Jiu; Yang, Jian-Ming; Xu, Xin; He, Dong-Zhi

    2009-09-01

    With the incessant fluctuations in oil prices and increasing stress from environmental pollution, renewed attention is being paid to the microbial production of biofuels from renewable sources. As a gasoline substitute, butanol has advantages over traditional fuel ethanol in terms of energy density and hygroscopicity. A variety of cheap substrates have been successfully applied in the production of biobutanol, highlighting the commercial potential of biobutanol development. In this review, in order to better understand the process of acetone-butanol-ethanol production, traditional clostridia fermentation is discussed. Sporulation is probably induced by solvent formation, and the molecular mechanism leading to the initiation of sporulation and solventogenesis is also investigated. Different strategies are employed in the metabolic engineering of clostridia that aim to enhancing solvent production, improve selectivity for butanol production, and increase the tolerance of clostridia to solvents. However, it will be hard to make breakthroughs in the metabolic engineering of clostridia for butanol production without gaining a deeper understanding of the genetic background of clostridia and developing more efficient genetic tools for clostridia. Therefore, increasing attention has been paid to the metabolic engineering of E. coli for butanol production. The importation and expression of a non-clostridial butanol-producing pathway in E. coli is probably the most promising strategy for butanol biosynthesis. Due to the lower butanol titers in the fermentation broth, simultaneous fermentation and product removal techniques have been developed to reduce the cost of butanol recovery. Gas stripping is the best technique for butanol recovery found so far.

  12. Modulation of the Acetone/Butanol Ratio during Fermentation of Corn Stover-Derived Hydrolysate by Clostridium beijerinckii Strain NCIMB 8052.

    PubMed

    Liu, Zi-Yong; Yao, Xiu-Qing; Zhang, Quan; Liu, Zhen; Wang, Ze-Jie; Zhang, Yong-Yu; Li, Fu-Li

    2017-04-01

    Producing biobutanol from lignocellulosic biomass has shown promise to ultimately reduce greenhouse gases and alleviate the global energy crisis. However, because of the recalcitrance of a lignocellulosic biomass, a pretreatment of the substrate is needed which in many cases releases soluble lignin compounds (SLCs), which inhibit growth of butanol-producing clostridia. In this study, we found that SLCs changed the acetone/butanol ratio (A/B ratio) during butanol fermentation. The typical A/B molar ratio during Clostridium beijerinckii NCIMB 8052 batch fermentation with glucose as the carbon source is about 0.5. In the present study, the A/B molar ratio during batch fermentation with a lignocellulosic hydrolysate as the carbon source was 0.95 at the end of fermentation. Structural and redox potential changes of the SLCs were characterized before and after fermentation by using gas chromatography/mass spectrometry and electrochemical analyses, which indicated that some exogenous SLCs were involved in distributing electron flow to C. beijerinckii, leading to modulation of the redox balance. This was further demonstrated by the NADH/NAD(+) ratio and trxB gene expression profile assays at the onset of solventogenic growth. As a result, the A/B ratio of end products changed significantly during C. beijerinckii fermentation using corn stover-derived hydrolysate as the carbon source compared to glucose as the carbon source. These results revealed that SLCs not only inhibited cell growth but also modulated the A/B ratio during C. beijerinckii butanol fermentation.IMPORTANCE Bioconversion of lignocellulosic feedstocks to butanol involves pretreatment, during which hundreds of soluble lignin compounds (SLCs) form. Most of these SLCs inhibit growth of solvent-producing clostridia. However, the mechanism by which these compounds modulate electron flow in clostridia remains elusive. In this study, the results revealed that SLCs changed redox balance by producing oxidative stress

  13. Butanol productivity enhancers in wheat straw hydrolyzate: employing potential of enhanced reaction rate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butanol production by fermentation is gaining momentum due to increased prices of fossil fuels. This biofuel is a major product of acetone-butanol-ethanol (ABE) fermentation that can be produced from hydrolyzed agricultural residues and/or corn. A control glucose (60 g/L) based batch fermentation us...

  14. Novel developments in butanol fermentation: Microbial genetics to agricultural substrates, process technology, and downstream processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butanol is the major product of acetone-butanol-ethanol (ABE; ratio 3:6:1) fermentation. It can be produced from various carbohydrates such as glucose, corn, molasses, and whey permeate (a by-product of the dairy industry) using microbial strains such as Clostridium beijerinckii and/or C. acetobuty...

  15. The Formation of Ethanol in Postmortem Tissues

    DTIC Science & Technology

    2004-02-01

    for ethanol analysis. The postmortem tissue specimens received by our laboratory have generally been subjected to severe trauma and may have been...Furthermore, the tissue specimens received by our laboratory typically have been subjected to trauma as a result of the violent nature of avia- tion...uoride, t-butanol, acetaldehyde , methanol, 2-propanol, acetone, n-propanol, isobutanol, n-butanol, sec-butanol and ethanol were purchased from Sigma

  16. Surface tension isotherms of the dioxane-acetone-water and glycerol-ethanol-water ternary systems

    NASA Astrophysics Data System (ADS)

    Dzhambulatov, R. S.; Dadashev, R. Kh.; Elimkhanov, D. Z.; Dadashev, I. N.

    2016-10-01

    The results of the experimental and theoretical studies of the concentration dependence of surface tension of aqueous solutions of the 1,4-dioxane-acetone-water and glycerol-ethanol-water ternary systems were given. The studies were performed by the hanging-drop method on a DSA100 tensiometer. The maximum error of surface tension was 1%. The theoretical models for calculating the surface tension of the ternary systems of organic solutions were analyzed.

  17. Continuous syngas fermentation for the production of ethanol, n-propanol and n-butanol.

    PubMed

    Liu, Kan; Atiyeh, Hasan K; Stevenson, Bradley S; Tanner, Ralph S; Wilkins, Mark R; Huhnke, Raymond L

    2014-01-01

    Syngas fermentation to fuels is a technology on the verge of commercialization. Low cost of fermentation medium is important for process feasibility. The use of corn steep liquor (CSL) instead of yeast extract (YE) in Alkalibaculum bacchi strain CP15 bottle fermentations reduced the medium cost by 27% and produced 78% more ethanol. When continuous fermentation was performed in a 7-L fermentor, 6g/L ethanol was obtained in the YE and YE-free media. When CSL medium was used in continuous fermentation, the maximum produced concentrations of ethanol, n-propanol and n-butanol were 8 g/L, 6 g/L and 1 g/L, respectively. n-Propanol and n-butanol were not typical products of strain CP15. A 16S rRNA gene-based survey revealed a mixed culture in the fermentor dominated by A. bacchi strain CP15 (56%) and Clostridium propionicum (34%). The mixed culture presents an opportunity for higher alcohols production from syngas.

  18. Co-production of acetone and ethanol with molar ratio control enables production of improved gasoline or jet fuel blends.

    PubMed

    Baer, Zachary C; Bormann, Sebastian; Sreekumar, Sanil; Grippo, Adam; Toste, F Dean; Blanch, Harvey W; Clark, Douglas S

    2016-10-01

    The fermentation of simple sugars to ethanol has been the most successful biofuel process to displace fossil fuel consumption worldwide thus far. However, the physical properties of ethanol and automotive components limit its application in most cases to 10-15 vol% blends with conventional gasoline. Fermentative co-production of ethanol and acetone coupled with a catalytic alkylation reaction could enable the production of gasoline blendstocks enriched in higher-chain oxygenates. Here we demonstrate a synthetic pathway for the production of acetone through the mevalonate precursor hydroxymethylglutaryl-CoA. Expression of this pathway in various strains of Escherichia coli resulted in the co-production of acetone and ethanol. Metabolic engineering and control of the environmental conditions for microbial growth resulted in controllable acetone and ethanol production with ethanol:acetone molar ratios ranging from 0.7:1 to 10.0:1. Specifically, use of gluconic acid as a substrate increased production of acetone and balanced the redox state of the system, predictively reducing the molar ethanol:acetone ratio. Increases in ethanol production and the molar ethanol:acetone ratio were achieved by co-expression of the aldehyde/alcohol dehydrogenase (AdhE) from E. coli MG1655 and by co-expression of pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (AdhB) from Z. mobilis. Controlling the fermentation aeration rate and pH in a bioreactor raised the acetone titer to 5.1 g L(-1) , similar to that obtained with wild-type Clostridium acetobutylicum. Optimizing the metabolic pathway, the selection of host strain, and the physiological conditions employed for host growth together improved acetone titers over 35-fold (0.14-5.1 g/L). Finally, chemical catalysis was used to upgrade the co-produced ethanol and acetone at both low and high molar ratios to higher-chain oxygenates for gasoline and jet fuel applications. Biotechnol. Bioeng. 2016;113: 2079-2087. © 2016 Wiley

  19. Butanol production in a first-generation Brazilian sugarcane biorefinery: technical aspects and economics of greenfield projects.

    PubMed

    Mariano, Adriano Pinto; Dias, Marina O S; Junqueira, Tassia L; Cunha, Marcelo P; Bonomi, Antonio; Filho, Rubens Maciel

    2013-05-01

    The techno-economics of greenfield projects of a first-generation sugarcane biorefinery aimed to produce ethanol, sugar, power, and n-butanol was conducted taking into account different butanol fermentation technologies (regular microorganism and mutant strain with improved butanol yield) and market scenarios (chemicals and automotive fuel). The complete sugarcane biorefinery with the batch acetone-butanol-ethanol (ABE) fermentation process was simulated using Aspen Plus®. The biorefinery was designed to process 2 million tonne sugarcane per year and utilize 25%, 50%, and 25% of the available sugarcane juice to produce sugar, ethanol, and butanol, respectively. The investment on a biorefinery with butanol production showed to be more attractive [14.8% IRR, P(IRR>12%)=0.99] than the conventional 50:50 (ethanol:sugar) annexed plant [13.3% IRR, P(IRR>12%)=0.80] only in the case butanol is produced by an improved microorganism and traded as a chemical.

  20. Two-stage in situ gas stripping for enhanced butanol fermentation and energy-saving product recovery

    SciTech Connect

    Xue, C; Zhao, JB; Liu, FF; Lu, CC; Yang, ST; Bai, FW

    2013-05-01

    Two-stage gas stripping for butanol recovery from acetone-butanol-ethanol (ABE) fermentation with Clostridium acetobutylicum JB200 in a fibrous bed bioreactor was studied. Compared to fermentation without in situ gas stripping, more ABE (10.0 g/L acetone, 19.2 g/L butanol, 1.7 g/L ethanol vs. 7.9 g/L acetone, 16.2 g/L butanol, 1.4 g/L ethanol) were produced, with a higher butanol yield (0.25 g/g vs. 0.20 g/g) and productivity (0.40 g/L.h vs. 0.30 g/L-h) due to reduced butanol inhibition. The first-stage gas stripping produced a condensate containing 175.6 g/L butanol (227.0 g/L ABE), which after phase separation formed an organic phase containing 612.3 g/L butanol (660.7 g/L ABE) and an aqueous phase containing 101.3 g/L butanol (153.2 g/L ABE). After second-stage gas stripping, a highly concentrated product containing 420.3 g/L butanol (532.3 g/L ABE) was obtained. The process is thus effective in producing high-titer butanol that can be purified with much less energy. (C) 2012 Elsevier Ltd. All rights reserved.

  1. Energy-efficient recovery of butanol from model solutions and fermentation broth by adsorption.

    PubMed

    Qureshi, N; Hughes, S; Maddox, I S; Cotta, M A

    2005-07-01

    This article discusses the separation of butanol from aqueous solutions and/or fermentation broth by adsorption. Butanol fermentation is also known as acetone butanol ethanol (ABE) or solvent fermentation. Adsorbents such as silicalite, resins (XAD-2, XAD-4, XAD-7, XAD-8, XAD-16), bone charcoal, activated charcoal, bonopore, and polyvinylpyridine have been studied. Use of silicalite appears to be the more attractive as it can be used to concentrate butanol from dilute solutions (5 to 790-810 g L(-1)) and results in complete desorption of butanol (or ABE). In addition, silicalite can be regenerated by heat treatment. The energy requirement for butanol recovery by adsorption-desorption processes has been calculated to be 1,948 kcal kg(-1) butanol as compared to 5,789 kcal kg(-1) butanol by steam stripping distillation. Other techniques such as gas stripping and pervaporation require 5,220 and 3,295 kcal kg(-1) butanol, respectively.

  2. Sensitivity of silica microspheres modified by xerogel layers to acetone and ethanol

    NASA Astrophysics Data System (ADS)

    Matějec, Vlastimil; Todorov, Filip; Jelinek, Michal; Fibrich, Martin; Chomát, Miroslav; Kubeček, Václav; Berková, Daniela

    2011-05-01

    The paper deals with the preparation and characterization of whispering-gallery-mode silica spherical microresonators and with effects of liquid acetone, ethanol, and xerogel layers applied onto these microresonators on their resonance spectra. Microrespheres with diameters ranging from 320 to 360 μm have been prepared by heating a tip of a silica fiber with a hydrogen-oxygen burner. The microspheres were excited by a fiber taper or a bulk prism and their resonance spectra were measured. Values of the Q factor from 104 to 106 have been determined from these spectra. In experiments, it has been found that short contact of microspheres with acetone causes a shift of resonance dips due to surface effects caused by acetone. A decrease of the Q factor has been observed with a microresonator onto which a xerogel silica layer was applied by the sol-gel method. A very high decrease of the Q factor has been observed when the silica microresonator was brought in contact with liquid ethanol.

  3. An economic evaluation of biological conversion of wheat straw to butanol: A biofuel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A cost estimation study was performed for a biological butanol production plant with a capacity of 150 x 10**6 kg butanol/year. Wheat straw was used as a feedstock. In addition to butanol, acetone (78.05 x 10**6 kg/year) and ethanol (28.54 x 10**6 kg/year) would also be produced. The total capital c...

  4. Nucleation of ethanol, propanol, butanol, and pentanol: A systematic experimental study along the homologous series

    NASA Astrophysics Data System (ADS)

    Manka, Alexandra A.; Wedekind, Jan; Ghosh, David; Höhler, Kristina; Wölk, Judith; Strey, Reinhard

    2012-08-01

    We present homogeneous vapor-liquid nucleation rates of the 1-alcohols (CnH2n+1OH, n = 2-4) measured in the well-established two-valve nucleation pulse chamber as well as in a novel one-piston nucleation pulse chamber at temperatures between 235 and 265 K. The nucleation rates and critical cluster sizes show a very systematic behavior with respect to the hydrocarbon chain length of the alcohol, just as their thermo-physical parameters such as surface tension, vapor pressure, and density would suggest. For all alcohols, except ethanol, predictions of classical nucleation theory lie several orders of magnitude below the experimental results and show a strong temperature-dependence typically found in nucleation experiments. The more recent Reguera-Reiss theory [J. Phys. Chem. B 108(51), 19831 (2004)] achieves reasonably good predictions for 1-propanol, 1-butanol, and 1-pentanol, and independent of the temperature. Ethanol, however, clearly shows the influence of strong association between molecules even in the vapor phase. We also scaled all experimental results with classic nucleation theory to compare our data with other data from the literature. We find the same overall temperature trend for all measurement series together but inverted and inconsistent temperature trends for individual 1-propanol and 1-butanol measurements in other devices. Overall, our data establishe a comprehensive and reliable data set that forms an ideal basis for comparison with nucleation theory.

  5. Regulation of the sol locus genes for butanol and acetone formation in Clostridium acetobutylicum ATCC 824 by a putative transcriptional repressor.

    PubMed

    Nair, R V; Green, E M; Watson, D E; Bennett, G N; Papoutsakis, E T

    1999-01-01

    A gene (orf1, now designated solR) previously identified upstream of the aldehyde/alcohol dehydrogenase gene aad (R. V. Nair, G. N. Bennett, and E. T. Papoutsakis, J. Bacteriol. 176:871-885, 1994) was found to encode a repressor of the sol locus (aad, ctfA, ctfB and adc) genes for butanol and acetone formation in Clostridium acetobutylicum ATCC 824. Primer extension analysis identified a transcriptional start site 35 bp upstream of the solR start codon. Amino acid comparisons of SolR identified a potential helix-turn-helix DNA-binding motif in the C-terminal half towards the center of the protein, suggesting a regulatory role. Overexpression of SolR in strain ATCC 824(pCO1) resulted in a solvent-negative phenotype owing to its deleterious effect on the transcription of the sol locus genes. Inactivation of solR in C. acetobutylicum via homologous recombination yielded mutants B and H (ATCC 824 solR::pO1X) which exhibited deregulated solvent production characterized by increased flux towards butanol and acetone formation, earlier induction of aad, lower overall acid production, markedly improved yields of solvents on glucose, a prolonged solvent production phase, and increased biomass accumulation compared to those of the wild-type strain.

  6. Technical and economic assessment of processes for the production of butanol and acetone. Phase two: analysis of research advances. Energy Conversion and Utilization Technologies Program

    SciTech Connect

    1984-08-01

    The initial objective of this work was to develop a methodology for analyzing the impact of technological advances as a tool to help establish priorities for R and D options in the field of biocatalysis. As an example of a biocatalyzed process, butanol/acetone fermentation (ABE process) was selected as the specific topic of study. A base case model characterizing the technology and economics associated with the ABE process was developed in the previous first phase of study. The project objectives were broadened in this second phase of work to provide parametric estimates of the economic and energy impacts of a variety of research advances in the hydrolysis, fermentation and purification sections of the process. The research advances analyzed in this study were based on a comprehensive literature review. The six process options analyzed were: continuous ABE fermentaton; vacuum ABE fermentation; Baelene solvent extraction; HRI's Lignol process; improved prehydrolysis/dual enzyme hydrolysis; and improved microorganism tolerance to butanol toxicity. Of the six options analyzed, only improved microorganism tolerance to butanol toxicity had a significant positive effect on energy efficiency and economics. This particular process option reduced the base case production cost (including 10% DCF return) by 20% and energy consumption by 16%. Figures and tables.

  7. Butanol production from concentrated lactose/whey permeate: Use of pervaporation membrane to recover and concentrate product

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In these studies butanol (acetone butanol ethanol, or ABE) was produced from concentrated lactose/whey permeate containing 211 gL-1 lactose. Fermentation of such a highly concentrated lactose solution was possible due to simultaneous product removal using a pervaporation membrane. In this system a p...

  8. Process integration for simultaneous saccharification, fermentation, and recovery (SSFR): Production of butanol from corn stover using Clostridium beijerinckii P260

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simultaneous saccharification, fermentation, and recovery (SSFR) process was developed for production of acetone butanol ethanol (AB or ABE), of which butanol is the main product, from corn stover employing Clostridium beijerinckii P260. Of the 86 gL^-1^ corn stover, over 97% of the sugars were r...

  9. Power-grade butanol recovery and utilization

    SciTech Connect

    Noon, R.

    1982-02-12

    As an alternative to the traditional recovery systems, it was proposed in a previous publication that the n-butanol/acetone/ethanol fermentation products could be recovered as a power grade fuel blend and used directly as a fuel. This would affect a savings in process energy requirements because each chemical component would not have to be processed individually to technical grade purity. Further, some residual water could be tolerated in the fuel blend. To develop such a power grade fuel recovery scheme beyond the conceptual stage, the Energy Research and Resource Division of the Kansas Energy Office undertook a two-fold program to demonstrate and test a power grade butanol/acetone/ethanol fuel recovery system, and further to demonstrate the feasibility of using the fuel blend in a standard type engine. A development program was initiated to accomplish the following objectives: design and test an operational power grade butanol recovery plant that would operate at one liter per hour output; and test and assess the performance of power grade butanol in a spark ignition automotive engine. This project has demonstrated that recovery of a power grade butanol fuel blend is simple and can be accomplished at a considered energy advantage over ethanol. It was further demonstrated that such a power grade blend works well in a typical spark ignition engine.

  10. Acetone enhances the direct analysis of total condensed tannins in plant tissues by the butanol-HCl-iron assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The butanol-HCl spectrophotometric assay is widely used to quantify extractable and insoluble forms of condensed tannin (CT, syn. proanthocyanidin) in foods, feeds, and foliage of herbaceous and woody plants. However, this method underestimates total CT content when applied directly to plant materia...

  11. Bioproduction of butanol in bioreactors: new insights from simultaneous in situ butanol recovery to eliminate product toxicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Simultaneous acetone butanol ethanol (ABE) fermentation by Clostridium beijerinckii 260 and in situ product recovery was investigated using a vacuum process operated in two modes: continuous and intermittent. Integrated batch fermentations and ABE recovery were conducted at 37 deg C using a 14-L bio...

  12. Life-cycle assessment of corn-based butanol as a potential transportation fuel.

    SciTech Connect

    Wu, M.; Wang, M.; Liu, J.; Huo, H.; Energy Systems

    2007-12-31

    Butanol produced from bio-sources (such as corn) could have attractive properties as a transportation fuel. Production of butanol through a fermentation process called acetone-butanol-ethanol (ABE) has been the focus of increasing research and development efforts. Advances in ABE process development in recent years have led to drastic increases in ABE productivity and yields, making butanol production worthy of evaluation for use in motor vehicles. Consequently, chemical/fuel industries have announced their intention to produce butanol from bio-based materials. The purpose of this study is to estimate the potential life-cycle energy and emission effects associated with using bio-butanol as a transportation fuel. The study employs a well-to-wheels analysis tool--the Greenhouse Gases, Regulated Emissions and Energy Use in Transportation (GREET) model developed at Argonne National Laboratory--and the Aspen Plus{reg_sign} model developed by AspenTech. The study describes the butanol production from corn, including grain processing, fermentation, gas stripping, distillation, and adsorption for products separation. The Aspen{reg_sign} results that we obtained for the corn-to-butanol production process provide the basis for GREET modeling to estimate life-cycle energy use and greenhouse gas emissions. The GREET model was expanded to simulate the bio-butanol life cycle, from agricultural chemical production to butanol use in motor vehicles. We then compared the results for bio-butanol with those of conventional gasoline. We also analyzed the bio-acetone that is coproduced with bio-butanol as an alternative to petroleum-based acetone. Our study shows that, while the use of corn-based butanol achieves energy benefits and reduces greenhouse gas emissions, the results are affected by the methods used to treat the acetone that is co-produced in butanol plants.

  13. Ultrasound-enhanced recovery of butanol/ABE by pervaporation.

    PubMed

    Menchavez, Russel Navarro; Ha, Sung Ho

    2013-11-01

    The search for renewable sources of energy has led to renewed interests on the biochemical route for the production of butanol. Butanol production suffers from several drawbacks, mainly caused by butanol inhibition to the butanol-producing microorganism which makes it economically uncompetitive against the chemical process. One possible solution proposed is the in situ recovery of acetone-butanol-ethanol (ABE). Among the in situ recovery options, membrane processes like pervaporation have a great potential. Thus, the effects of temperature, feed concentration, and ultrasound irradiation on permeate concentration and permeation flux for the recovery of butanol/ABE by pervaporation from aqueous solutions were investigated in this study. In the butanol-water system, permeate butanol concentration as well as flux increased with an increase in temperature and butanol feed concentration. When pervaporation studies with ABE-water mixture were carried out at 60 °C for 2, 4, 8, 16, and 24 h, pervaporation profile revealed an optimal permeate concentration as well as permeation flux. Applications of ultrasound irradiation on pervaporation improved permeate concentration by about 23 g/L for both butanol and ABE. Ultrasound irradiation also improved butanol and ABE mass permeation flux by about 13 and 11 %, respectively.

  14. Investigation of uncertainties associated with the production of n-butanol through ethanol catalysis in sugarcane biorefineries.

    PubMed

    Pereira, Lucas G; Dias, Marina O S; MacLean, Heather L; Bonomi, Antonio

    2015-08-01

    This study evaluated the viability of n-butanol production integrated within a first and second generation sugarcane biorefinery. The evaluation included a deterministic analysis as well as a stochastic approach, the latter using Monte Carlo simulation. Results were promising for n-butanol production in terms of revenues per tonne of processed sugarcane, but discouraging with respect to internal rate of return (IRR). The uncertainty analysis determined there was high risk involved in producing n-butanol and co-products from ethanol catalysis. It is unlikely that these products and associated production route will be financially attractive in the short term without lower investment costs, supportive public policies and tax incentives coupled with biofuels' production strategies.

  15. Temperature dependent selectivity towards ethanol and acetone of Dy3+-doped In2O3 nanoparticles

    NASA Astrophysics Data System (ADS)

    Anand, Kanica; Kaur, Jasmeet; Singh, Ravi Chand; Thangaraj, Rengasamy

    2017-02-01

    In this paper, the influence of Dy3+ doping on the sensor response (SR) and selectivity of In2O3 sensors for selective detection of ethanol and acetone has been studied. (0, 1, 5, 10%) Dy3+-doped In2O3 nanoparticles has been prepared employing a co-precipitation method and characterized by XRD, RAMAN, TEM, EDS and Photoluminescence studies. It has been observed that Dy3+ doping inhibits the nanoparticles growth and increases the lattice constant, structural disorder, activation energy, defect concentration and surface basicity. The highest SR for 10% Dy3+-doped In2O3 sensor has been ascribed to small size, high defects, high surface basicity and large lattice distortion.

  16. Cross-Selectivity Enhancement of Poly(vinylidene fluoride-hexafluoropropylene)-Based Sensor Arrays for Detecting Acetone and Ethanol

    PubMed Central

    Daneshkhah, Ali; Shrestha, Sudhir; Siegel, Amanda; Varahramyan, Kody; Agarwal, Mangilal

    2017-01-01

    Two methods for cross-selectivity enhancement of porous poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP)/carbon black (CB) composite-based resistive sensors are provided. The sensors are tested with acetone and ethanol in the presence of humid air. Cross-selectivity is enhanced using two different methods to modify the basic response of the PVDF-HFP/CB sensing platform. In method I, the adsorption properties of PVDF-HFP/CB are altered by adding a polyethylene oxide (PEO) layer or by treating with infrared (IR). In method II, the effects of the interaction of acetone and ethanol are enhanced by adding diethylene carbonate (DEC) or PEO dispersed in DEC (PEO/DEC) to the film. The results suggest the approaches used in method I alter the composite ability to adsorb acetone and ethanol, while in method II, they alter the transduction characteristics of the composite. Using these approaches, sensor relative response to acetone was increased by 89% compared with the PVDF-HFP/CB untreated film, whereas sensor relative response to ethanol could be decreased by 57% or increased by 197%. Not only do these results demonstrate facile methods for increasing sensitivity of PVDF-HFP/CB film, used in parallel they demonstrate a roadmap for enhancing system cross-selectivity that can be applied to separate units on an array. Fabrication methods, experimental procedures and results are presented and discussed. PMID:28294961

  17. Production of Butyric Acid and Butanol from Biomass

    SciTech Connect

    Ramey, David E.; Yang, Shang-Tian

    2005-08-25

    Butanol replaced gasoline gallon for gallon in a 10,000 miles trip across the United States without the need to highly modify a ’92 Buick (your existing car today). Butanol can now be made for less than ethanol and yields more Btu’s from the same corn, making the plow to tire equation positive – more energy out than it takes to make it and Butanol is much safer. Butanol when substituted for gasoline gives better gas mileage and does not pollute as tested in 10 states. Butanol should now receive the same recognition as ethanol in U.S. legislation “ethanol/butanol”. There is abundant plant biomass present as low-value agricultural commodities or processing wastes requiring proper disposal to avoid pollution problems. One example is in the corn refinery industry, which processes more than 13% of the ~9.5 billion bushels (~240 million metric tons) of corn annually produced in the U.S. to produce high-fructose-corn-syrup, dextrose, starch, and fuel alcohol, and generates more than 10 million metric tons of corn byproducts that are currently of limited use and pose significant environmental problems. The abundant inexpensive renewable resources as feedstock for fermentation, and recent advances in the fields of biotechnology and bioprocessing have resulted in a renewed interest in the fermentation production of chemicals and fuels, including n-butanol. The historic acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum is one of the oldest known industrial fermentations. It was ranked second only to ethanol fermentation by yeast in its scale of production, and is one of the largest biotechnological processes ever known. However, since the 1950's industrial ABE fermentation has declined continuously, and almost all butanol is now produced via petrochemical routes (Chemical Marketing Reporter, 1993). Butanol is an important industrial solvent and is a better fuel for replacing gasoline – gallon for gallon than ethanol. Current butanol prices

  18. Anaerobic Biodegradation of Biofuels (Ethanol, Biodiesel, n-Propanol, n-Butanol, and iso-Butanol) in Aquifer Sediment

    EPA Science Inventory

    In the late 1990s, there was a perception that “green” fuels such as ethanol posed less of a threat to ground water because they were readily degraded. This lead to a conclusion that the transition to “green” fuels would require less vigilance and that the existing level of effo...

  19. Anaerobic Biodegradation of Biofuels (Ethanol, Biodiesel, n-Propanol, n-Butanol, and iso-Butanol) in Aquifer Sediment (PP)

    EPA Science Inventory

    In the late 1990s, there was a perception that “green” fuels such as ethanol posed less of a threat to ground water because they were readily degraded. This lead to a conclusion that the transition to “green” fuels would require less vigilance and that the existing level of effo...

  20. Assessment of potential life-cycle energy and greenhouse gas emission effects from using corn-based butanol as a transportation fuel.

    SciTech Connect

    Wu, M.; Wang, M.; Liu, J.; Huo, H.; Energy Systems

    2008-01-01

    Since advances in the ABE (acetone-butanol-ethanol) fermentation process in recent years have led to significant increases in its productivity and yields, the production of butanol and its use in motor vehicles have become an option worth evaluating. This study estimates the potential life-cycle energy and emission effects associated with using bio-butanol as a transportation fuel. It employs a well-to-wheels (WTW) analysis tool: the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The estimates of life-cycle energy use and greenhouse gas (GHG) emissions are based on an Aspen Plus(reg. sign) simulation for a corn-to-butanol production process, which describes grain processing, fermentation, and product separation. Bio-butanol-related WTW activities include corn farming, corn transportation, butanol production, butanol transportation, and vehicle operation. In this study, we also analyzed the bio-acetone that is coproduced with bio-butanol as an alternative to petroleum-based acetone. We then compared the results for bio-butanol with those of conventional gasoline. Our study shows that driving vehicles fueled with corn-based butanol produced by the current ABE fermentation process could result in substantial fossil energy savings (39%-56%) and avoid large percentage of the GHG emission burden, yielding a 32%-48% reduction relative to using conventional gasoline. On energy basis, a bushel of corn produces less liquid fuel from the ABE process than that from the corn ethanol dry mill process. The coproduction of a significant portion of acetone from the current ABE fermentation presents a challenge. A market analysis of acetone, as well as research and development on robust alternative technologies and processes that minimize acetone while increase the butanol yield, should be conducted.

  1. Assessment of potential life-cycle energy and greenhouse gas emission effects from using corn-based butanol as a transportation fuel.

    PubMed

    Wu, May; Wang, Michael; Liu, Jiahong; Huo, Hong

    2008-01-01

    Since advances in the ABE (acetone-butanol-ethanol) fermentation process in recent years have led to significant increases in its productivity and yields, the production of butanol and its use in motor vehicles have become an option worth evaluating. This study estimates the potential life-cycle energy and emission effects associated with using bio-butanol as a transportation fuel. It employs a well-to-wheels (WTW) analysis tool: the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The estimates of life-cycle energy use and greenhouse gas (GHG) emissions are based on an Aspen Plus(R) simulation for a corn-to-butanol production process, which describes grain processing, fermentation, and product separation. Bio-butanol-related WTW activities include corn farming, corn transportation, butanol production, butanol transportation, and vehicle operation. In this study, we also analyzed the bio-acetone that is coproduced with bio-butanol as an alternative to petroleum-based acetone. We then compared the results for bio-butanol with those of conventional gasoline. Our study shows that driving vehicles fueled with corn-based butanol produced by the current ABE fermentation process could result in substantial fossil energy savings (39%-56%) and avoid large percentage of the GHG emission burden, yielding a 32%-48% reduction relative to using conventional gasoline. On energy basis, a bushel of corn produces less liquid fuel from the ABE process than that from the corn ethanol dry mill process. The coproduction of a significant portion of acetone from the current ABE fermentation presents a challenge. A market analysis of acetone, as well as research and development on robust alternative technologies and processes that minimize acetone while increase the butanol yield, should be conducted.

  2. Flame-Made Nb-Doped TiO2 Ethanol and Acetone Sensors

    PubMed Central

    Phanichphant, Sukon; Liewhiran, Chaikarn; Wetchakun, Khatcharin; Wisitsoraat, Anurat; Tuantranont, Adisorn

    2011-01-01

    Undoped TiO2 and TiO2 nanoparticles doped with 1–5 at.% Nb were successfully produced in a single step by flame spray pyrolysis (FSP). The phase and crystallite size were analyzed by XRD. The BET surface area (SSABET) of the nanoparticles was measured by nitrogen adsorption. The trend of SSABET on the doping samples increased and the BET equivalent particle diameter (dBET) (rutile) increased with the higher Nb-doping concentrations while dBET (anatase) remained the same. The morphology and accurate size of the primary particles were further investigated by high-resolution transmission electron microscopy (HRTEM). The crystallite sizes of undoped and Nb-doped TiO2 spherical were in the range of 10–20 nm. The sensing films were prepared by spin coating technique. The mixing sample was spin-coated onto the Al2O3 substrates interdigitated with Au electrodes. The gas sensing of acetone (25–400 ppm) was studied at operating temperatures ranging from 300–400 °C in dry air, while the gas sensing of ethanol (50–1,000 ppm) was studied at operating temperatures ranging from 250–400 °C in dry air. PMID:22346586

  3. Mutual diffusion of binary liquid mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride.

    PubMed

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y Mauricio; Vrabec, Jadran

    2016-03-28

    Mutual diffusion coefficients of all 20 binary liquid mixtures that can be formed out of methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride without a miscibility gap are studied at ambient conditions of temperature and pressure in the entire composition range. The considered mixtures show a varying mixing behavior from almost ideal to strongly non-ideal. Predictive molecular dynamics simulations employing the Green-Kubo formalism are carried out. Radial distribution functions are analyzed to gain an understanding of the liquid structure influencing the diffusion processes. It is shown that cluster formation in mixtures containing one alcoholic component has a significant impact on the diffusion process. The estimation of the thermodynamic factor from experimental vapor-liquid equilibrium data is investigated, considering three excess Gibbs energy models, i.e., Wilson, NRTL, and UNIQUAC. It is found that the Wilson model yields the thermodynamic factor that best suits the simulation results for the prediction of the Fick diffusion coefficient. Four semi-empirical methods for the prediction of the self-diffusion coefficients and nine predictive equations for the Fick diffusion coefficient are assessed and it is found that methods based on local composition models are more reliable. Finally, the shear viscosity and thermal conductivity are predicted and in most cases favorably compared with experimental literature values.

  4. A carbon nanotube filled polydimethylsiloxane hybrid membrane for enhanced butanol recovery

    PubMed Central

    Xue, Chuang; Du, Guang-Qing; Chen, Li-Jie; Ren, Jian-Gang; Sun, Jian-Xin; Bai, Feng-Wu; Yang, Shang-Tian

    2014-01-01

    The carbon nanotubes (CNTs) filled polydimethylsiloxane (PDMS) hybrid membrane was fabricated to evaluate its potential for butanol recovery from acetone-butanol-ethanol (ABE) fermentation broth. Compared with the homogeneous PDMS membrane, the CNTs filled into the PDMS membrane were beneficial for the improvement of butanol recovery in butanol flux and separation factor. The CNTs acting as sorption-active sites with super hydrophobicity could give an alternative route for mass transport through the inner tubes or along the smooth surface. The maximum total flux and butanol separation factor reached up to 244.3 g/m2·h and 32.9, respectively, when the PDMS membrane filled with 10 wt% CNTs was used to separate butanol from the butanol/water solution at 80°C. In addition, the butanol flux and separation factor increased dramatically as temperature increased from 30°C to 80°C in feed solution since the higher temperature produced more free volumes in polymer chains to facilitate butanol permeation. A similar increase was also observed when butanol titer in solution increased from 10 g/L to 25 g/L. Overall, the CNTs/PDMS hybrid membrane with higher butanol flux and selectivity should have good potential for pervaporation separation of butanol from ABE fermentation broth. PMID:25081019

  5. Role of Calcination Temperature on the Hydrotalcite Derived MgO–Al2O3 in Converting Ethanol to Butanol

    SciTech Connect

    Ramasamy, Karthikeyan K.; Gray, Michel; Job, Heather; Santosa, Daniel; Li, Xiaohong Shari; Devaraj, Arun; Karkamkar, Abhi; Wang, Yong

    2015-10-09

    In the base catalyzed ethanol condensation reactions, the calcined MgO-Al2O3 derived hydrotalcites used broadly as catalytic material and the calcination temperature plays a big role in determining the catalytic activity. The characteristic of the hydrotalcite material treated between catalytically relevant temperatures 450ºC and 800ºC have been studied with respect to the physical, chemical, and structural properties and compared with catalytic activity testing. With the increasing calcination temperature, the total measured catalytic basicity dropped linearly with the calcination temperature and the total measured acidity stayed the same for all the calcination temperatures except 800ºC. However, the catalyst activity testing does not show any direct correlation between the measured catalytic basicity and the catalyst activity to the ethanol condensation reaction to form 1-butanol. The highest ethanol conversion of 44 percent with 1-butanol selectivity of 50 percent was achieved for the 600ºC calcined hydrotalcite material.

  6. Sorption and phase distribution of ethanol and butanol blended gasoline vapours in the vadose zone after release.

    PubMed

    Ugwoha, Ejikeme; Andresen, John M

    2014-03-01

    The sorption and phase distribution of 20% ethanol and butanol blended gasoline (E20 and B20) vapours have been examined in soils with varying soil organic matter (SOM) and water contents via laboratory microcosm experiments. The presence of 20% alcohol reduced the sorption of gasoline compounds by soil as well as the mass distribution of the compounds to soil solids. This effect was greater for ethanol than butanol. Compared with the sorption coefficient (Kd) of unblended gasoline compounds, the Kd of E20 gasoline compounds decreased by 54% for pentane, 54% for methylcyclopentane (MCP) and 63% for benzene, while the Kd of B20 gasoline compounds decreased by 39% for pentane, 38% for MCP and 49% for benzene. The retardation factor (R) of E20 gasoline compounds decreased by 53% for pentane, 53% for MCP and 48% for benzene, while the R of B20 gasoline compounds decreased by 39% for pentane, 37% for MCP and 38% for benzene. For all SOM and water contents tested, the Kd and R of all gasoline compounds were in the order of unblended gasoline > B20 > E20, indicating that the use of high ethanol volume in gasoline to combat climate change could put the groundwater at greater risk of contamination.

  7. Effect of cocultures on the production of butanol by Clostridium sp. [C. butyricum, C. pasteurianum, C. butylicum, and C. acetobutylicum

    SciTech Connect

    Bergstrom, S.L.; Foutch, G.L.

    1983-01-01

    One of the problems with the production of butanol by fermentation is that a mixture of other solvents, primarily acetone and ethanol, are also produced. The ratio of butanol to acetone to ethanol is approximately 6:3:1. If the metabolism of the Clostridium can be shifted away from acetone and ethanol, then a higher percentage of the sugar carbon can be converted to butanol. This study examines the effects that cocultures of Clostridium have on the yield of butanol from glucose. C. butyricum and C. pasteurianum produced high concentrations of butyric acid from these sugars. C. butylicum and C. acetobutylicum are capable of utilizing this butyric acid for energy, resulting in butanol production. By using combinations of these strains in coculture a higher initial conversion to butyric acid would be expected followed by a higher overall yield of butanol. This coculture would not be expected to have an increased tolerance for butanol in the fermentation broth. 6 references, 1 figure, 3 tables.

  8. Enhanced Butanol Production Obtained by Reinforcing the Direct Butanol-Forming Route in Clostridium acetobutylicum

    PubMed Central

    Jang, Yu-Sin; Lee, Jin Young; Lee, Joungmin; Park, Jin Hwan; Im, Jung Ae; Eom, Moon-Ho; Lee, Julia; Lee, Sang-Hyun; Song, Hyohak; Cho, Jung-Hee; Seung, Do Young; Lee, Sang Yup

    2012-01-01

    ABSTRACT Butanol is an important industrial solvent and advanced biofuel that can be produced by biphasic fermentation by Clostridium acetobutylicum. It has been known that acetate and butyrate first formed during the acidogenic phase are reassimilated to form acetone-butanol-ethanol (cold channel). Butanol can also be formed directly from acetyl-coenzyme A (CoA) through butyryl-CoA (hot channel). However, little is known about the relative contributions of the two butanol-forming pathways. Here we report that the direct butanol-forming pathway is a better channel to optimize for butanol production through metabolic flux and mass balance analyses. Butanol production through the hot channel was maximized by simultaneous disruption of the pta and buk genes, encoding phosphotransacetylase and butyrate kinase, while the adhE1D485G gene, encoding a mutated aldehyde/alcohol dehydrogenase, was overexpressed. The ratio of butanol produced through the hot channel to that produced through the cold channel increased from 2.0 in the wild type to 18.8 in the engineered BEKW(pPthlAAD**) strain. By reinforcing the direct butanol-forming flux in C. acetobutylicum, 18.9 g/liter of butanol was produced, with a yield of 0.71 mol butanol/mol glucose by batch fermentation, levels which are 160% and 245% higher than those obtained with the wild type. By fed-batch culture of this engineered strain with in situ recovery, 585.3 g of butanol was produced from 1,861.9 g of glucose, with the yield of 0.76 mol butanol/mol glucose and productivity of 1.32 g/liter/h. Studies of two butanol-forming routes and their effects on butanol production in C. acetobutylicum described here will serve as a basis for further metabolic engineering of clostridia aimed toward developing a superior butanol producer. PMID:23093384

  9. Butanol production from hydrothermolysis-pretreated switchgrass: Quantification of inhibitors and detoxification of hydrolyzate.

    PubMed

    Liu, Kan; Atiyeh, Hasan K; Pardo-Planas, Oscar; Ezeji, Thaddeus C; Ujor, Victor; Overton, Jonathan C; Berning, Kalli; Wilkins, Mark R; Tanner, Ralph S

    2015-08-01

    The present study evaluated butanol production from switchgrass based on hydrothermolysis pretreatment. The inhibitors present in the hydrolyzates were measured. Results showed poor butanol production (1g/L) with non-detoxified hydrolyzate. However, adjusting the pH of the non-detoxified hydrolyzate to 6 and adding 4 g/L CaCO3 increased butanol formation to about 6g/L. There was about 1g/L soluble lignin content (SLC), and various levels of furanic and phenolic compounds found in the non-detoxified hydrolyzate. Detoxification of hydrolyzates with activated carbon increased the butanol titer to 11 g/L with a total acetone, butanol and ethanol (ABE) concentration of 17 g/L. These results show the potential of butanol production from hydrothermolysis pretreated switchgrass.

  10. Production of Butanol (A Biofuel) from Agricultural Residues: Part I - Use of Barley Straw Hydrolysate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fermentation of dilute sulfuric acid barley straw hydrolyzate (BSH; undiluted/untreated) by Clostridium beijerinckii P260 resulted in the production of 7.09 gL**-1 ABE (acetone butanol ethanol; AB or ABE), an ABE yield of 0.33, and productivity of 0.10 gL**-1h**-1. This level of ABE is much less th...

  11. Effects of acetone, acetonitrile, ethanol, methanol and DMSO on cytochrome P450 in rainbow trout (Oncorhynchus mykiss) hepatic microsomes.

    PubMed

    Sakalli, Sidika; Burkina, Viktoriia; Zlabek, Vladimir; Zamaratskaia, Galia

    2015-01-01

    In vitro impacts of five organic solvents on cytochrome P450 (CYP450) enzyme activity were investigated using hepatic microsomes of rainbow trout. The rates of several CYP450-mediated reactions were investigated at solvent concentrations ranging from 0.01% to 3%. The solvents greatly affected all tested reactions. In at least 0.8% ethanol, 2% methanol or acetone, 1% acetonitrile or 3% dimethyl sulfoxide (DMSO), 7-ethoxyresorufin-O-deethylase (EROD) activity decreased and at 3% acetonitrile or ethanol, it was undetected. At 3%, all tested solvents except methanol reduced 7-benzyloxy-4-trifluoromethylcoumarin-O-debenzylase (BFCOD) activity, but at low concentrations of ethanol (2% and lower) or DMSO (1% and lower), it was induced. This was not seen with the inclusion of a pre-incubation step. p-Nitrophenolhydroxylase (PNPH) activity was not affected at concentrations below 1% DMSO, and at 2% acetonitrile it was reduced, as it was above 1% methanol or 0.5% ethanol. Acetone did not affect PNPH activity with or without a pre-incubation step. In general, the degree of inhibition was similar with and without the pre-incubation step. We conclude that the concentration of organic solvent for solubilizing the substrate and inhibitor in in vitro microsomal studies should be minimized.

  12. Pervaporative butanol fermentation by Clostridium acetobutylicum B18

    SciTech Connect

    Geng, Q.; Park, C.H. . Dept. of Agricultural Engineering)

    1994-04-15

    Extractive acetone-butanol-ethanol (ABE) fermentation was carried out successfully using pervaporation and a low-acid-producing Clostridium acetobutylicum B18. A pervaporation module with 0.17 m[sup 2] of surface area was made of silicone membrane of 240 [mu]m thickness. Pervaporation experiments using make-up solutions showed that butanol and acetone fluxes increased linearly with their concentrations in the aqueous phase. Fickian diffusion coefficients were constants for fixed air flow rates, and increased at higher sweep air flow rates. During batch and fed-batch fermentation, pervaporation at an air flow rate of 8 L/min removed butanol and acetone efficiently. Butanol concentration was maintained below 4.5 g/L even though Clostridium acetobutylicum B18 produced butanol steadily. Pervaporation could not remove organic acids efficiently, but organic acids did not accumulate because strain B18 produced little organic acid and recycled added organic acids efficiently. With pervaporation, glucose consumption rate increased compared to without pervaporation, and up to 160 g/L of glucose was consumed during 80 h. Cell growth was not inhibited by possible salt accumulation or oxygen diffusion through the silicone tubing. The culture volume was maintained relatively constant during fed-batch operation because of an offsetting effect of water and product removal by pervaporation and addition of nutrient supplements.

  13. Butanol production from the effluent of hydrogen fermentation.

    PubMed

    Chen, W H; Chen, S Y; Chao, S J; Jian, Z C

    2011-01-01

    The purpose of the study was to recover butanol from the effluent of the hydrogen-producing bioreactor containing acetate, butyrate, and carbohydrate. The butanol production by Clostridium beijerinckii NRRL B592 was evaluated under both unsterilized and sterilized conditions for examining the potential of butanol production for the practical application. Sucrose of 10 g/L and butyrate of 2 g/L coupled with acetate buffer were used to mimic the effluent. Sucrose was completely consumed in the both unsterilized and sterilized conditions during acetone-butanol-ethanol (ABE) fermentation. However, the results illustrate that the carbohydrate consumption rate in the unsterilized condition was higher than that in the sterilized condition. The maximum butanol concentrations of 3,500 and 3,750 mg/L were achieved in the sterilized and unsterilized conditions, respectively. Meanwhile, it was found that the acetate and the butyrate concentrations of 600 and 1,500 mg/L, and 300 and 1,000 mg/L were ingested to yield butanol in the sterilized condition and in the unsterilized condition, respectively. The results concluded that high levels of acetate and butyrate could eliminate the interference of other microbial populations, resulting in the enrichment of C. beijerinckii NRRL B592 in the fermentor. The butanol production by C. beijerinckii NRRL B592 could be, therefore, produced from the effluent of the hydrogen-producing bioreactor. It promised that the microbial butanol production is one of attractive bioprocesses to recover energy from wastes.

  14. Fermentative production of butanol: Perspectives on synthetic biology.

    PubMed

    Nanda, Sonil; Golemi-Kotra, Dasantila; McDermott, John C; Dalai, Ajay K; Gökalp, Iskender; Kozinski, Janusz A

    2017-03-09

    Apprehensions relating to global warming, climate change, pollution, rising energy demands as well as fluctuating crude oil prices and supply are leading to a shift in global interest to find suitable alternatives to fossil fuels. This review aims to highlight the many different facets of butanol as an advanced next-generation transportation biofuel. Butanol has fuel properties almost on a par with gasoline, such as high energy content, low vapor pressure, non-hygroscopic nature, less volatility, flexible fuel blends and high octane number. The paper reviews some recent advances in acetone-butanol-ethanol fermentation with special emphasis on the primary challenges encountered in butanol fermentation, including butanol toxicity, solvent intolerance and bacteriophage contamination. The mechanisms for butanol recovery techniques have been covered along with their benefits and limitations. A comprehensive discussion of genetic and metabolic engineering of butanol-producing microorganisms is made for the prospective development of industrially-relevant strains that can overcome the technical challenges involved in efficient butanol production.

  15. Integrated distillation-membrane process for bio-ethanol and bio-butanol recovery from actual fermentation broths: Separation energy efficiency and fate of secondary fermentation products

    EPA Science Inventory

    A hybrid process integrating vapor stripping with vapor compression and vapor permeation membrane separation, termed Membrane Assisted Vapor Stripping (MAVS), was evaluated for recovery and dehydration of ethanol and/or 1-butanol from aqueous solution as an alternative to convent...

  16. Enhanced butanol production obtained by reinforcing the direct butanol-forming route in Clostridium acetobutylicum.

    PubMed

    Jang, Yu-Sin; Lee, Jin Young; Lee, Joungmin; Park, Jin Hwan; Im, Jung Ae; Eom, Moon-Ho; Lee, Julia; Lee, Sang-Hyun; Song, Hyohak; Cho, Jung-Hee; Seung, Do Young; Lee, Sang Yup

    2012-10-23

    Butanol is an important industrial solvent and advanced biofuel that can be produced by biphasic fermentation by Clostridium acetobutylicum. It has been known that acetate and butyrate first formed during the acidogenic phase are reassimilated to form acetone-butanol-ethanol (cold channel). Butanol can also be formed directly from acetyl-coenzyme A (CoA) through butyryl-CoA (hot channel). However, little is known about the relative contributions of the two butanol-forming pathways. Here we report that the direct butanol-forming pathway is a better channel to optimize for butanol production through metabolic flux and mass balance analyses. Butanol production through the hot channel was maximized by simultaneous disruption of the pta and buk genes, encoding phosphotransacetylase and butyrate kinase, while the adhE1(D485G) gene, encoding a mutated aldehyde/alcohol dehydrogenase, was overexpressed. The ratio of butanol produced through the hot channel to that produced through the cold channel increased from 2.0 in the wild type to 18.8 in the engineered BEKW(pPthlAAD(**)) strain. By reinforcing the direct butanol-forming flux in C. acetobutylicum, 18.9 g/liter of butanol was produced, with a yield of 0.71 mol butanol/mol glucose by batch fermentation, levels which are 160% and 245% higher than those obtained with the wild type. By fed-batch culture of this engineered strain with in situ recovery, 585.3 g of butanol was produced from 1,861.9 g of glucose, with the yield of 0.76 mol butanol/mol glucose and productivity of 1.32 g/liter/h. Studies of two butanol-forming routes and their effects on butanol production in C. acetobutylicum described here will serve as a basis for further metabolic engineering of clostridia aimed toward developing a superior butanol producer. IMPORTANCE Renewable biofuel is one of the answers to solving the energy crisis and climate change problems. Butanol produced naturally by clostridia has superior liquid fuel characteristics and thus has

  17. A Comparison of the Microbial Production and Combustion Characteristics of Three Alcohol Biofuels: Ethanol, 1-Butanol, and 1-Octanol.

    PubMed

    Kremer, Florian; Blank, Lars M; Jones, Patrik R; Akhtar, M Kalim

    2015-01-01

    Over the last decade, microbes have been engineered for the manufacture of a variety of biofuels. Saturated linear-chain alcohols have great potential as transport biofuels. Their hydrocarbon backbones, as well as oxygenated content, confer combustive properties that make it suitable for use in internal combustion engines. Herein, we compared the microbial production and combustion characteristics of ethanol, 1-butanol, and 1-octanol. In terms of productivity and efficiency, current microbial platforms favor the production of ethanol. From a combustion standpoint, the most suitable fuel for spark-ignition engines would be ethanol, while for compression-ignition engines it would be 1-octanol. However, any general conclusions drawn at this stage regarding the most superior biofuel would be premature, as there are still many areas that need to be addressed, such as large-scale purification and pipeline compatibility. So far, the difficulties in developing and optimizing microbial platforms for fuel production, particularly for newer fuel candidates, stem from our poor understanding of the myriad biological factors underpinning them. A great deal of attention therefore needs to be given to the fundamental mechanisms that govern biological processes. Additionally, research needs to be undertaken across a wide range of disciplines to overcome issues of sustainability and commercial viability.

  18. A Comparison of the Microbial Production and Combustion Characteristics of Three Alcohol Biofuels: Ethanol, 1-Butanol, and 1-Octanol

    PubMed Central

    Kremer, Florian; Blank, Lars M.; Jones, Patrik R.; Akhtar, M. Kalim

    2015-01-01

    Over the last decade, microbes have been engineered for the manufacture of a variety of biofuels. Saturated linear-chain alcohols have great potential as transport biofuels. Their hydrocarbon backbones, as well as oxygenated content, confer combustive properties that make it suitable for use in internal combustion engines. Herein, we compared the microbial production and combustion characteristics of ethanol, 1-butanol, and 1-octanol. In terms of productivity and efficiency, current microbial platforms favor the production of ethanol. From a combustion standpoint, the most suitable fuel for spark-ignition engines would be ethanol, while for compression-ignition engines it would be 1-octanol. However, any general conclusions drawn at this stage regarding the most superior biofuel would be premature, as there are still many areas that need to be addressed, such as large-scale purification and pipeline compatibility. So far, the difficulties in developing and optimizing microbial platforms for fuel production, particularly for newer fuel candidates, stem from our poor understanding of the myriad biological factors underpinning them. A great deal of attention therefore needs to be given to the fundamental mechanisms that govern biological processes. Additionally, research needs to be undertaken across a wide range of disciplines to overcome issues of sustainability and commercial viability. PMID:26301219

  19. Integrated butanol recovery for an advanced biofuel: current state and prospects.

    PubMed

    Xue, Chuang; Zhao, Jing-Bo; Chen, Li-Jie; Bai, Feng-Wu; Yang, Shang-Tian; Sun, Jian-Xin

    2014-04-01

    Butanol has recently gained increasing interest due to escalating prices in petroleum fuels and concerns on the energy crisis. However, the butanol production cost with conventional acetone-butanol-ethanol fermentation by Clostridium spp. was higher than that of petrochemical processes due to the low butanol titer, yield, and productivity in bioprocesses. In particular, a low butanol titer usually leads to an extremely high recovery cost. Conventional biobutanol recovery by distillation is an energy-intensive process, which has largely restricted the economic production of biobutanol. This article thus reviews the latest studies on butanol recovery techniques including gas stripping, liquid-liquid extraction, adsorption, and membrane-based techniques, which can be used for in situ recovery of inhibitory products to enhance butanol production. The productivity of the fermentation system is improved efficiently using the in situ recovery technology; however, the recovered butanol titer remains low due to the limitations from each one of these recovery technologies, especially when the feed butanol concentration is lower than 1 % (w/v). Therefore, several innovative multi-stage hybrid processes have been proposed and are discussed in this review. These hybrid processes including two-stage gas stripping and multi-stage pervaporation have high butanol selectivity, considerably higher energy and production efficiency, and should outperform the conventional processes using single separation step or method. The development of these new integrated processes will give a momentum for the sustainable production of industrial biobutanol.

  20. Prospective and development of butanol as an advanced biofuel.

    PubMed

    Xue, Chuang; Zhao, Xin-Qing; Liu, Chen-Guang; Chen, Li-Jie; Bai, Feng-Wu

    2013-12-01

    Butanol has been acknowledged as an advanced biofuel, but its production through acetone-butanol-ethanol (ABE) fermentation by clostridia is still not economically competitive, due to low butanol yield and titer. In this article, update progress in butanol production is reviewed. Low price and sustainable feedstocks such as lignocellulosic residues and dedicated energy crops are needed for butanol production at large scale to save feedstock cost, but processes are more complicated, compared to those established for ABE fermentation from sugar- and starch-based feedstocks. While rational designs targeting individual genes, enzymes or pathways are effective for improving butanol yield, global and systems strategies are more reasonable for engineering strains with stress tolerance controlled by multigenes. Compared to solvent-producing clostridia, engineering heterologous species such as Escherichia coli and Saccharomyces cerevisiae with butanol pathway might be a solution for eliminating the formation of major byproducts acetone and ethanol so that butanol yield can be improved significantly. Although batch fermentation has been practiced for butanol production in industry, continuous operation is more productive for large scale production of butanol as a biofuel, but a single chemostat bioreactor cannot achieve this goal for the biphasic ABE fermentation, and tanks-in-series systems should be optimized for alternative feedstocks and new strains. Moreover, energy saving is limited for the distillation system, even total solvents in the fermentation broth are increased significantly, since solvents are distilled to ~40% by the beer stripper, and more than 95% water is removed with the stillage without phase change, even with conventional distillation systems, needless to say that advanced chemical engineering technologies can distil solvents up to ~90% with the beer stripper, and the multistage pressure columns can well balance energy consumption for solvent fraction

  1. Butanol fermentation from microalgae-derived carbohydrates after ionic liquid extraction.

    PubMed

    Gao, Kai; Orr, Valerie; Rehmann, Lars

    2016-04-01

    Lipid extracted algae (LEA) is an attractive feedstock for alcohol fuel production as it is a non-food crop which is largely composed of readily fermented carbohydrates like starch rather than the more recalcitrant lignocellulosic materials currently under intense development. This study compares the suitability of ionic liquid extracted algae (ILEA) and hexane extracted algae (HEA) for acetone, butanol, and ethanol (ABE) fermentation. The highest butanol titers (8.05 g L(-1)) were achieved with the fermentation of the acid hydrolysates of HEA, however, they required detoxification to support product formation after acid hydrolysis while ILEA did not. Direct ABE fermentation of ILEA and HEA (without detoxification) starches resulted in a butanol titer of 4.99 and 6.63 g L(-1), respectively, which significantly simplified the LEA to butanol process. The study demonstrated the compatibility of producing biodiesel and butanol from a single feedstock which may help reduce the feedstock costs of each individual process.

  2. Use of the composite membrane of poly(ether-block-amide) and carbon nanotubes (CNTs) in a pervaporation system incorporated with fermentation for butanol production by Clostridium acetobutylicum.

    PubMed

    Yen, Hong-Wei; Chen, Zhi-Heng; Yang, I-Kuan

    2012-04-01

    Fermentation incorporated with pervaporation was regarded as an efficient way to relieve the feedback inhibition of butanol in acetone-butanol-ethanol (ABE) fermentation. The addition of CNTs (carbon nanotubes) to PEBA (poly(ether-block-amide)) could greatly enhance the removal flux of solvents (acetone, butanol and ethanol) in a model solution test. The butanol removing rate results in a 61% increase in the batch with PEBA+CNTs (5%) membrane compared with that of the batch with PEBA alone. Besides the increase of removal flux, the addition of CNTs enforces the mechanical strength of the pervaporation membrane, which leads to more resistance for a longer operational time. The combination of a 5-L fermenter with the pervaporation membrane of PEBA+CNTs (10%) indicates a 20% increase both in productivity and yield compared to using PEBA. In conclusion, the addition of CNTs to a PEBA pervaporation membrane has great potential when applied in the ABE fermentation industry.

  3. Improving Butanol Fermentation To Enter the Advanced Biofuel Market

    PubMed Central

    Tracy, Bryan P.

    2012-01-01

    ABSTRACT 1-Butanol is a large-volume, intermediate chemical with favorable physical and chemical properties for blending with or directly substituting for gasoline. The per-volume value of butanol, as a chemical, is sufficient for investing into the recommercialization of the classical acetone-butanol-ethanol (ABE) (E. M. Green, Curr. Opin. Biotechnol. 22:337–343, 2011) fermentation process. Furthermore, with modest improvements in three areas of the ABE process, operating costs can be sufficiently decreased to make butanol an economically viable advanced biofuel. The three areas of greatest interest are (i) maximizing yields of butanol on any particular substrate, (ii) expanding substrate utilization capabilities of the host microorganism, and (iii) reducing the energy consumption of the overall production process, in particular the separation and purification operations. In their study in the September/October 2012 issue of mBio, Jang et al. [mBio 3(5):e00314-12, 2012] describe a comprehensive study on driving glucose metabolism in Clostridium acetobutylicum to the production of butanol. Moreover, they execute a metabolic engineering strategy to achieve the highest yet reported yields of butanol on glucose. PMID:23232720

  4. An Evaluation of Methanol, Ethanol, the Propanols, and the Butanols as Ship Propulsion Fuels.

    DTIC Science & Technology

    1976-09-01

    This report evaluates the alkyl monohydric alcohols from methanol through the butanols (C-1 to C-4) as Navy ship propulsion fuels. Properties of the alcohols from the technical literature are compared with the properties of Navy ship propulsion hydrocarbon fuels (Diesel Fuel Marine and JP-5). None of these alcohols is suitable as a direct substitute or as an extender for the currently used ship propulsion fuels. The use of methanol with its low volumetric energy content would entail over a 50% reduction in range

  5. [Adaptation processes in mice during chronic combined exposure to radiation and chemical compounds (acetone, ethanol, acetaldehyde) innate to exploration missions].

    PubMed

    Tatarkin, S V; Shafirkin, A V; Mukhamedieva, L N; Barantseva, M Iu; Ivanova, S M

    2012-01-01

    The paper reports the results of experimental investigation with mice subjected to 63-day of daily 10-fold fractionated gamma-irradiation at the total dose of 350 cGy followed by 70-day exposure to chemical mixture (acetone, ethanol, acetate aldehyde) at close to maximum permissible concentrations innate to piloted space vehicles (MPCpsv). Measured levels of radiation and known radiation sensitivity of mice were used to model absorbed dose to cosmonauts on an exploration mission. Functional shifts in the hematopoietic system and changes in biochemical parameters of erythrocytes indicative of energy exchange and redox potential were tracked up during the combined radiation-chemical exposure and 90 days of recovery. It was shown that adaptation caused pronounced and strongly pronounced tension of regulatory mechanisms, particularly under the effects of radiation. High tension still persisted in the recovery period.

  6. Acetone-butanol-ethanol (ABE) production by Clostridium beijerinckii from wheat straw hydrolysates: efficient use of penta and hexa carbohydrates.

    PubMed

    Bellido, Carolina; Loureiro Pinto, Marina; Coca, Mónica; González-Benito, Gerardo; García-Cubero, María Teresa

    2014-09-01

    ABE fermentation by Clostridium beijerinckii of steam-exploded and ozonated wheat straw hydrolysates was investigated. In steam-exploded hydrolysates, highest yields of 0.40 g/g ABE yield and 127.71 g ABE/kg wheat straw were achieved when the whole slurry from the pretreatment was used. In ozonated hydrolysates, 0.32 g/g ABE yield and 79.65 g ABE/kg wheat straw were obtained from washed ozonated wheat straw. Diverse effects were observed in steam explosion and ozonolysis of wheat straw which resulted in hemicellulose removal and acid insoluble lignin solubilization, respectively. SEM analysis showed structural differences in untreated and pretreated biomass. Depending on the operational strategy, after pretreatment and enzymatic hydrolysis, the glucose recovery ranged between 65.73-66.49% and 63.22-65.23% and the xylose recovery ranged between 45.19-61.00% and 34.54-40.91% in steam-exploded and ozonated hydrolysates, respectively. The effect of the main inhibitory compounds found in hydrolysates (oxalic acid, acetic acid, 5-hydroxymethylfurfural and furfural) was studied through ABE fermentation in model media.

  7. Responses of lone star tick (acari: ixodidae) nymphs to the repellent deet applied in acetone and ethanol solutions in vitro bioassays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Behavioral bioassays remain a standard tool in the discovery, development, and registration of repellents. Although tick repellent bioassays tend to be rather uncomplicated, several factors can influence their outcomes. Typically repellent bioassays use a solvent, such as acetone or ethanol, to disp...

  8. Acetone enhances the direct analysis of Procyanidin- and Prodelphinidin-based condensed tannins in lotus species by the butanol-HCl-iron assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The butanol-HCl spectrophotometric assay is widely used for quantifying extractable and insoluble condensed tannins (CT, syn. proanthocyanidins) in foods, feeds, and foliage of herbaceous and woody plants, but the method underestimates total CT content when applied directly to plant material. To imp...

  9. Acetone production in solventogenic Clostridium species: new insights from non-enzymatic decarboxylation of acetoacetate.

    PubMed

    Han, Bei; Gopalan, Venkat; Ezeji, Thaddeus Chukwuemeka

    2011-08-01

    Development of a butanologenic strain with high selectivity for butanol production is often proposed as a possible route for improving the economics of biobutanol production by solventogenic Clostridium species. The acetoacetate decarboxylase (aadc) gene encoding acetoacetate decarboxylase (AADC), which catalyzes the decarboxylation of acetoacetate into acetone and CO(2), was successfully disrupted by homologous recombination in solventogenic Clostridium beijerinckii NCIMB 8052 to generate an aadc ( - ) mutant. Our fermentation studies revealed that this mutant produces a maximum acetone concentration of 3 g/L (in P2 medium), a value comparable to that produced by wild-type C. beijerinckii 8052. Therefore, we postulated that AADC-catalyzed decarboxylation of acetoacetate is not the sole means for acetone generation. Our subsequent finding that non-enzymatic decarboxylation of acetoacetate in vitro, under conditions similar to in vivo acetone-butanol-ethanol (ABE) fermentation, produces 1.3 to 5.2 g/L acetone between pH 6.5 and 4 helps rationalize why various knock-out and knock-down strategies designed to disrupt aadc in solventogenic Clostridium species did not eliminate acetone production during ABE fermentation. Based on these results, we discuss alternatives to enhance selectivity for butanol production.

  10. Key Roles of Lewis Acid-base Pairs on ZnxZryOz in Direct Ethanol/Acetone to Isobutene Conversion

    SciTech Connect

    Sun, Junming; Baylon, Rebecca A.; Liu, Changjun; Mei, Donghai; Martin, Kevin J.; Venkitasubramanian, Padmesh; Wang, Yong

    2016-01-20

    The effects of surface acidity on the cascade ethanol-to-isobutene conversion were studied using ZnxZryOz catalysts. The ethanol-to-isobutene reaction was found to be limited by the secondary reaction of the key intermediate, acetone, namely the acetone-to-isobutene reaction. Although the catalysts with coexisting Brønsted acidity could catalyze the rate-limiting acetone-to-isobutene reaction, the presence of Brønsted acidity is also detrimental. First, secondary isobutene isomerization is favored, producing a mixture of butene isomers. Second, undesired polymerization and coke formation prevail, leading to rapid catalyst deactivation. Most importantly, both steady-state and kinetic reaction studies as well as FTIR analysis of adsorbed acetone-d6 and D2O unambiguously showed that a highly active and selective nature of balanced Lewis acid-base pairs was masked by the coexisting Brønsted acidity in the aldolization and self-deoxygenation of acetone to isobutene. As a result, ZnxZryOz catalysts with only Lewis acid-base pairs were discovered, on which nearly a theoretical selectivity to isobutene (~88.9%) was successfully achieved, which has never been reported before. Moreover, the absence of Brønsted acidity in such ZnxZryOz catalysts also eliminates the side isobutene isomerization and undesired polymerization/coke reactions, resulting in the production of high purity isobutene with significantly improved catalyst stability (< 2% activity loss after 200 h time-on-stream). This work not only demonstrates a balanced Lewis acid-base pair for the highly active and selective cascade ethanol-to-isobutene reaction, but also sheds light on the rational design of selective and robust acid-base catalyst for C-C coupling via aldolization reaction.

  11. Enhancing Butanol Production under the Stress Environments of Co-Culturing Clostridium acetobutylicum/Saccharomyces cerevisiae Integrated with Exogenous Butyrate Addition.

    PubMed

    Luo, Hongzhen; Ge, Laibing; Zhang, Jingshu; Zhao, Yanli; Ding, Jian; Li, Zhigang; He, Zhenni; Chen, Rui; Shi, Zhongping

    2015-01-01

    In this study, an efficient acetone-butanol-ethanol (ABE) fermentation strategy integrating Clostridium acetobutylicum/Saccharomyces cerevisiae co-culturing system with exogenous butyrate addition, was proposed and experimentally conducted. In solventogenic phase, by adding 0.2 g-DCW/L-broth viable S. cerevisiae cells and 4.0 g/L-broth concentrated butyrate solution into C. acetobutylicum culture broth, final butanol concentration and butanol/acetone ratio in a 7 L anaerobic fermentor reached the highest levels of 15.74 g/L and 2.83 respectively, with the increments of 35% and 43% as compared with those of control. Theoretical and experimental analysis revealed that, the proposed strategy could, 1) extensively induce secretion of amino acids particularly lysine, which are favorable for both C. acetobutylicum survival and butanol synthesis under high butanol concentration environment; 2) enhance the utilization ability of C. acetobutylicum on glucose and over-produce intracellular NADH for butanol synthesis in C. acetobutylicum metabolism simultaneously; 3) direct most of extra consumed glucose into butanol synthesis route. The synergetic actions of effective amino acids assimilation, high rates of substrate consumption and NADH regeneration yielded highest butanol concentration and butanol ratio in C. acetobutylicum under this stress environment. The proposed method supplies an alternative way to improve ABE fermentation performance by traditional fermentation technology.

  12. Enhancing Butanol Production under the Stress Environments of Co-Culturing Clostridium acetobutylicum/Saccharomyces cerevisiae Integrated with Exogenous Butyrate Addition

    PubMed Central

    Luo, Hongzhen; Ge, Laibing; Zhang, Jingshu; Zhao, Yanli; Ding, Jian; Li, Zhigang; He, Zhenni; Chen, Rui; Shi, Zhongping

    2015-01-01

    In this study, an efficient acetone-butanol-ethanol (ABE) fermentation strategy integrating Clostridium acetobutylicum/Saccharomyces cerevisiae co-culturing system with exogenous butyrate addition, was proposed and experimentally conducted. In solventogenic phase, by adding 0.2 g-DCW/L-broth viable S. cerevisiae cells and 4.0 g/L-broth concentrated butyrate solution into C. acetobutylicum culture broth, final butanol concentration and butanol/acetone ratio in a 7 L anaerobic fermentor reached the highest levels of 15.74 g/L and 2.83 respectively, with the increments of 35% and 43% as compared with those of control. Theoretical and experimental analysis revealed that, the proposed strategy could, 1) extensively induce secretion of amino acids particularly lysine, which are favorable for both C. acetobutylicum survival and butanol synthesis under high butanol concentration environment; 2) enhance the utilization ability of C. acetobutylicum on glucose and over-produce intracellular NADH for butanol synthesis in C. acetobutylicum metabolism simultaneously; 3) direct most of extra consumed glucose into butanol synthesis route. The synergetic actions of effective amino acids assimilation, high rates of substrate consumption and NADH regeneration yielded highest butanol concentration and butanol ratio in C. acetobutylicum under this stress environment. The proposed method supplies an alternative way to improve ABE fermentation performance by traditional fermentation technology. PMID:26489085

  13. Optimization of butanol production from tropical maize stalk juice by fermentation with Clostridium beijerinckii NCIMB 8052.

    PubMed

    Wang, Yi; Blaschek, Hans P

    2011-11-01

    Mixed sugars from tropical maize stalk juice were used to carry out butanol fermentation with Clostridium beijerinckii NCIMB 8052. Batch experiments employing central composite design (CCD) and response surface methodology (RSM) optimization were performed to evaluate effects of three factors, i.e. pH, initial total sugar concentration, and agitation rate on butanol production. Optimum conditions of pH 6.7, sugar concentration 42.2g/L and agitation rate 48 rpm were predicted, under which a maximum butanol yield of 0.27 g/g-sugar was estimated. Further experiments demonstrated that higher agitation facilitated acetone production, leading to lower butanol selectivity in total acetone-butanol-ethanol (ABE). While glucose and fructose are more preferable by C. beijerinckii, sucrose can also be easily degraded by the microorganism. This study indicated that RSM is a useful approach for optimizing operational conditions for butanol production, and demonstrated that tropical maize, with high yield of biomass and stalk sugars, is a promising biofuel crop.

  14. Enhanced butanol production in a microbial electrolysis cell by Clostridium beijerinckii IB4.

    PubMed

    He, Ai-Yong; Yin, Chun-Yan; Xu, Hao; Kong, Xiang-Ping; Xue, Jia-Wei; Zhu, Jing; Jiang, Min; Wu, Hao

    2016-02-01

    Reducing power such as NADH is an essential factor for acetone/butanol/ethanol (ABE) fermentation using Clostridium spp. The objective of this study was to increase available NADH in Clostridium beijerinckii IB4 by a microbial electrolysis cell (MEC) with an electron carrier to enhance butanol production. First of all, a MEC was performed without electron carrier to study the function of cathodic potential applying. Then, various electron carriers were tested, and neutral red (NR)-amended cultures showed an increase of butanol concentration. Optimal NR concentration (0.1 mM) was used to add in a MEC. Electricity stimulated the cell growth obviously and dramatically diminished the fermentation time from 40 to 28 h. NR and electrically reduced NR improved the final butanol concentration and inhibited the acetone generation. In the MEC with NR, the butanol concentration, yield, proportion and productivity were increased by 12.2, 17.4, 7.2 and 60.3 %, respectively. To further understand the mechanisms of NR, cathodic potential applying and electrically reduced NR, NADH and NAD(+) levels, ATP levels and hydrogen production were determined. NR and electrically reduced NR also improved ATP levels and the ratio of NADH/NAD(+), whereas they decreased hydrogen production. Thus, the MEC is an efficient method for enhancing the butanol production.

  15. Improved efficiency of butanol production by absorbed lignocellulose fermentation.

    PubMed

    He, Qin; Chen, Hongzhang

    2013-03-01

    Alkali-treated steam-exploded corn stover (SECSAT) was used as solid substrate for acetone-butanol-ethanol (ABE) production by absorbed lignocellulose fermentation (ALF) using Clostridium acetobutylicum ATCC 824. The ABE concentration in ALF culture had increased by 47% compared with that in submerged culture. More surprisingly, the acetone production was promoted and ethanol production was lower in the presence of SECSAT than that in its absence. ALF was also successfully in cofermentation of glucose and xylose, although decreased fermentability with an increase in the proportion of xylose. An invariable chemical composition and dry weight of SECSAT was found in ALF. Partial simultaneous saccharification and fermentation of SECSAT using a certain amount of cellulase could not only enhance the ABE concentration by 71%, but also significantly increase the area proportion of fiber cells in SECSAT from 53% to 90%, which would be an excellent paper making material.

  16. Recent Advances in Catalytic Conversion of Ethanol to Chemicals

    SciTech Connect

    Sun, Junming; Wang, Yong

    2014-04-30

    With increased availability and decreased cost, ethanol is potentially a promising platform molecule for the production of a variety of value-added chemicals. In this review, we provide a detailed summary of recent advances in catalytic conversion of ethanol to a wide range of chemicals and fuels. We particularly focus on catalyst advances and fundamental understanding of reaction mechanisms involved in ethanol steam reforming (ESR) to produce hydrogen, ethanol conversion to hydrocarbons ranging from light olefins to longer chain alkenes/alkanes and aromatics, and ethanol conversion to other oxygenates including 1-butanol, acetaldehyde, acetone, diethyl ether, and ethyl acetate.

  17. The mechanism of switching from an acidogenic to butanol-acetone fermentation by Clostridium acetobutylicum. Technical progress report, July 1990--December 1992

    SciTech Connect

    Rogers, P.

    1992-12-31

    The overall objective of this project is to elucidate the detailed mechanism by which solvent-forming bacteria such as Clostridium acetobutylicum regulate the well-known shift in fermentation pathway between alcohol-acetone and organic acid production. It is desired to eventually isolate and describe: (1) the regulatory genes and protein elements that determine induction of synthesis of the solvent-pathway enzymes; and (2) how this regulation system interacts with the sporulatin induction and development program and with related pathways such as granulse and exopolysaccharide formation in clostridia. A working model forhow clostridial control systems work can be derived from recent research on stress systems in E. coli and sporulation in Bacillus subtilis.

  18. Combined Detoxification and In-situ Product Removal by a Single Resin During Lignocellulosic Butanol Production

    NASA Astrophysics Data System (ADS)

    Gao, Kai; Rehmann, Lars

    2016-07-01

    Phragmites australis (an invasive plant in North America) was used as feedstock for ABE (acetone-butanol-ethanol) fermentation by Clostridium saccharobutylicum. Sulphuric acid pretreated phragmites hydrolysate (SAEH) without detoxification inhibited butanol production (0.73 g/L butanol from 30 g/L sugars). The treatment of SAEH with resin L-493 prior the fermentation resulted in no inhibitory effects and an ABE titer of 14.44 g/L, including 5.49 g/L butanol was obtained, corresponding to an ABE yield and productivity of 0.49 g/g and 0.60 g/L/h, respectively. Dual functionality of the resin was realized by also using it as an in-situ product removal agent. Integrating in-situ product removal allowed for the use of high substrate concentrations without the typical product inhibition. Resin-detoxified SAEH was supplemented with neat glucose and an effective ABE titer of 33 g/L (including 13.7 g/L acetone, 16.4 g/L butanol and 1.9 g/L ethanol) was achieved with resin-based in-situ product removal, corresponding to an ABE yield and productivity of 0.41 g/g and 0.69 g/L/h, respectively. Both detoxification of the substrate and the products was achieved by the same resin, which was added prior the fermentation. Integrating hydrolysate detoxification and in-situ butanol removal in a batch process through single resin can potentially simplify cellulosic butanol production.

  19. Combined Detoxification and In-situ Product Removal by a Single Resin During Lignocellulosic Butanol Production

    PubMed Central

    Gao, Kai; Rehmann, Lars

    2016-01-01

    Phragmites australis (an invasive plant in North America) was used as feedstock for ABE (acetone-butanol-ethanol) fermentation by Clostridium saccharobutylicum. Sulphuric acid pretreated phragmites hydrolysate (SAEH) without detoxification inhibited butanol production (0.73 g/L butanol from 30 g/L sugars). The treatment of SAEH with resin L-493 prior the fermentation resulted in no inhibitory effects and an ABE titer of 14.44 g/L, including 5.49 g/L butanol was obtained, corresponding to an ABE yield and productivity of 0.49 g/g and 0.60 g/L/h, respectively. Dual functionality of the resin was realized by also using it as an in-situ product removal agent. Integrating in-situ product removal allowed for the use of high substrate concentrations without the typical product inhibition. Resin-detoxified SAEH was supplemented with neat glucose and an effective ABE titer of 33 g/L (including 13.7 g/L acetone, 16.4 g/L butanol and 1.9 g/L ethanol) was achieved with resin-based in-situ product removal, corresponding to an ABE yield and productivity of 0.41 g/g and 0.69 g/L/h, respectively. Both detoxification of the substrate and the products was achieved by the same resin, which was added prior the fermentation. Integrating hydrolysate detoxification and in-situ butanol removal in a batch process through single resin can potentially simplify cellulosic butanol production. PMID:27459906

  20. Adsorptive Separation of 1-Butanol from Aqueous Solutions Using MFI- and FER-Type Zeolite Frameworks: A Monte Carlo Study.

    PubMed

    DeJaco, Robert F; Bai, Peng; Tsapatsis, Michael; Siepmann, J Ilja

    2016-03-01

    Anaerobic fermentation can transform carbohydrates to yield a multicomponent mixture comprising mainly of acetone, 1-butanol, and ethanol (ABE) in a typical weight ratio of 3:6:1. Compared to ethanol, 1-butanol, the main product of ABE fermentation, offers significant advantages as a biofuel or a fuel additive. However, the toxicity of 1-butanol for cell cultures requires broth concentrations to be low in 1-butanol (≈1-2 wt %). An energy-efficient recovery method that performs well even at low 1-butanol concentrations is therefore necessary to ensure economic feasibility of the ABE fermentation process. In this work, configurational-bias Monte Carlo simulations in the Gibbs ensemble are performed to probe the adsorption of 1-butanol/water solutions onto all-siliceous zeolites with the framework types MFI and FER. At low solution concentration, the selectivity and capacity for 1-butanol in MFI are larger than those in FER, while the opposite is true for concentrations at or above those of ABE broths. Structural analysis at various loadings sheds light on the different sorbate-sorbate and sorbate-sorbent interactions that govern trends in adsorption in each zeolite.

  1. Anaerobic Biodegradation of Biofuels (Ethanol and Biodiesel) and Proposed Biofuels (n-Propanol, iso-Propanol, n-Butanol)

    EPA Science Inventory

    Biofuels, such as ethanol and biodiesel, are a growing component of the nation’s fuel supply. Ethanol is the primary biofuel in the US market, distributed as a blend with petroleum gasoline, in concentrations ranging from 10% ethanol (E10) to 85% ethanol (E85). Biodiesel, made fr...

  2. The mechanism of switching from an acidogenic to butanol-acetone fermentation by Clostridium acetobutylicum. Technical progress report, July 1990--June 1993

    SciTech Connect

    Rogers, P.

    1994-11-01

    The overall objective of this project was to elucidate the detailed mechanism by which solvent-forming bacteria such as Clostridium acetobutylicum regulate the well-known shift in fermentation pathway between alcohol-acetone and organic acid production. We eventually want to isolate and describe: (1) the regulatory genes and protein elements that determine induction of synthesis of the solvent-pathway enzymes; and (2) how this regulation system interacts with the sporulation induction and development program and with related pathways such as granulose and exopolysaccharide formation in clostridia. A working model for how clostridial control systems work can be derived from recent research on stress systems in E. coli and sporulation in Bacillus subtilis. This research was centered upon the technique of employing transposable elements that create gene fusions and mutations due to insertion in the chromosome of gram positive bacteria. Our approach was based on recent demonstration in our laboratory and by others of transconjugation of Tn916 into C. acetobutylicum and its insertion into the chromosome. A panel of strains with Tn916 inserts that are also solvent-negative and/or asporogenic were used to identify specific regulatory genes. A second approach was based upon electroporative transformation of plasmid PTV1 DNA carrying transposon Tn917 into C. acetobutylicum. Insertion of Tn917 lac to report activity of genes and functions in vegetative and stationary or slow-growing cells will be investigated.

  3. Improving performance of a gas stripping-based recovery system to remove butanol from Clostridium beijerinckii fermentation.

    PubMed

    Ezeji, Thaddeus C; Karcher, Patrick M; Qureshi, Nasib; Blaschek, Hans P

    2005-05-01

    The effect of factors such as gas recycle rate, bubble size, presence of acetone, and ethanol in the solution/broth were investigated in order to remove butanol from model solution or fermentation broth (also called acetone butanol ethanol or ABE or solvents). Butanol (8 g L(-1), model solution, Fig. 2) stripping rate was found to be proportional to the gas recycle rate. In the bubble size range attempted (< 0.5 and 0.5-5.0 mm), the bubble size did not have any effect on butanol removal rate (Fig. 3, model solution). In Clostridium beijerinckii fermentation, ABE productivity was reduced from 0.47 g L(-1) h(-1) to 0.25 g L(-1) h(-1) when smaller (< 0.5 mm) bubble size was used to remove ABE (Fig. 4, results reported as butanol/ABE concentration). The productivity was reduced as a result of addition of an excessive amount of antifoam used to inhibit the production of foam caused by the smaller bubbles. This suggested that the fermentation was negatively affected by antifoam.

  4. Comparison of the solubility of PVF and PVDF in supercritical CH{sub 2}F{sub 2} and CO{sub 2} and in CO{sub 2} with acetone, dimethyl ether, and ethanol

    SciTech Connect

    Lora, M.; Lim, J.S.; McHugh, M.A.

    1999-04-08

    Cloud-point data are reported at temperatures to 245 C and pressures to 2700 bar for poly(vinyl fluoride) (PVF) and poly(vinylidene fluoride) (PVDF) in CO{sub 2}, CH{sub 2}F{sub 2}, dimethyl ether (DME), acetone, and ethanol and in mixtures of CO{sub 2} with acetone, DME, and ethanol. PVF does not dissolve in CO{sub 2} even at 245 C and 2700 bar, but, PVF does dissolve in CH{sub 2}F{sub 2} at 180 C and pressures in excess of 1500 bar. To dissolve PVF in DME, pressures in excess of 550 bar and temperatures in excess of 130 C are needed although it only takes {approximately}100 bar to maintain a single phase to temperatures of {approximately}220 C with ethanol and acetone. Compared to the conditions needed to dissolve PVF, it takes hundreds of bar less pressure to dissolve PVDF in CO{sub 2}, CH{sub 2}F{sub 2}, and DME and {approximately}60 bar less pressure to dissolve it in acetone, but it does take {approximately}60 bar more pressure to dissolve it in ethanol. With CO{sub 2}, ethanol is a better cosolvent than acetone for both fluoropolymers at high temperatures and at low ethanol concentrations. However, when the temperature is decreased or the ethanol concentration is increased, it acts as an antisolvent probably due to ethanol self-association. Compared to ethanol and acetone, DME is not as good a cosolvent more than likely as a result of its lower density and smaller dipole moment. For all three cosolvents, their impact on the reduction of the cloud-point pressure diminishes with increasing cosolvent concentration. It is also evident that CO{sub 2} is an effective antisolvent since small amounts of it added to the polymer-cosolvent mixtures greatly increase the pressures needed to obtain a single phase.

  5. High-efficient n-butanol production by co-culturing Clostridium acetobutylicum and Saccharomyces cerevisiae integrated with butyrate fermentative supernatant addition.

    PubMed

    Luo, Hongzhen; Zeng, Qingwei; Han, Shuo; Wang, Zhaoyu; Dong, Qing; Bi, Yanhong; Zhao, Yuping

    2017-04-01

    Butanol is not only an important chemical intermediate and solvent in pharmaceutical and cosmetics industries, but also considered as an advanced biofuel. Although species of the natural host Clostridium have been engineered, butanol titers in the anaerobe seem to be limited by its intolerance to butanol less than 13 g/L. Here we aimed to develop a technology for enhancing butanol production by a co-culture system with butyrate fermentative supernatant addition. First, when adding 4.0 g/L butyrate into the acetone-butanol-ethanol (ABE) fermentation broth with single-shot at 24 h, the "acid crash" phenomenon occurred and the ABE fermentation performance deteriorated. Subsequently, we found that adding certain amino acids could effectively enhance butyrate re-assimilation, butanol tolerance and titer (from 11.1 to 14.8 g/L). Additionally, in order to decrease the raw material cost, butyrate fermentative supernatant produced by Clostridium tyrobutyricum was applied to butanol production in the Clostridium acetobutylicum/Saccharomyces cerevisiae co-culture system, instead of adding synthetic butyrate. Final butanol and total ABE concentrations reached higher levels of 16.3 and 24.8 g/L with increments of 46.8 and 37.8%, respectively. These results show that the proposed fermentation strategy has great potential for efficiently butanol production with an economic approach.

  6. Process economics of renewable biorefineries: butanol and ethanol production in integrated bioprocesses from lignocellulosics and other industrial by-products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter provides process economic details on production of butanol from lignocellulosic biomass and glycerol in integrated bioreactors where numerous unit operations are combined. In order to compare various processes, economic evaluations were performed using SuperPro Designer Software (versio...

  7. Butanol production by Clostridium beijerinckii ATCC 55025 from wheat bran.

    PubMed

    Liu, Ziyong; Ying, Yu; Li, Fuli; Ma, Cuiqing; Xu, Ping

    2010-05-01

    Wheat bran, a by-product of the wheat milling industry, consists mainly of hemicellulose, starch and protein. In this study, the hydrolysate of wheat bran pretreated with dilute sulfuric acid was used as a substrate to produce ABE (acetone, butanol and ethanol) using Clostridium beijerinckii ATCC 55025. The wheat bran hydrolysate contained 53.1 g/l total reducing sugars, including 21.3 g/l of glucose, 17.4 g/l of xylose and 10.6 g/l of arabinose. C. beijerinckii ATCC 55025 can utilize hexose and pentose simultaneously in the hydrolysate to produce ABE. After 72 h of fermentation, the total ABE in the system was 11.8 g/l, of which acetone, butanol and ethanol were 2.2, 8.8 and 0.8 g/l, respectively. The fermentation resulted in an ABE yield of 0.32 and productivity of 0.16 g l(-1) h(-1). This study suggests that wheat bran can be a potential renewable resource for ABE fermentation.

  8. Ex situ product recovery for enhanced butanol production by Clostridium beijerinckii.

    PubMed

    Lee, Sang-Hyun; Eom, Moon-Ho; Choi, Jin-Dal-Rae; Kim, Sooah; Kim, Jungyeon; Shin, Yong-An; Kim, Kyoung Heon

    2016-05-01

    In situ butanol recovery fermentation has been intensively studied as an effective alternative to conventional butanol production, which is limited due to the cellular toxicity of butanol. However, the low biocompatibility of adsorbents often leads to failure of in situ recovery fermentations. In this study, Clostridium beijerinckii NCIMB 8052 was cultured in flasks without shaking and in situ recovery fermentation was performed by using an adsorbent L493. The amounts of acetone, butanol, and ethanol (ABE) increased by 34.4 % in the presence of the adsorbent. In contrast, cell growth and production of organic acids and ABE were retarded in the 7-L batch fermentations with in situ butanol recovery. Cell damage occurred in the fermentor upon agitation in the presence of the adsorbent, unlike in static flask cultures with in situ recovery. Ex situ recovery fermentation using circulation of fermentation broth after mid-exponential phase of cell growth was developed to avoid adsorbent-cell incompatibility. No apparent cell damage was observed and 25.7 g/L of ABE was produced from 86.2 g/L glucose in the fed-batch mode using 7 L fermentors. Thus, ex situ recovery fermentation with C. beijerinckii is effective for enhancing butanol fermentation.

  9. Introducing a single secondary alcohol dehydrogenase into butanol-tolerant Clostridium acetobutylicum Rh8 switches ABE fermentation to high level IBE fermentation

    PubMed Central

    2012-01-01

    Background Previously we have developed a butanol tolerant mutant of Clostridium acetobutylicum Rh8, from the wild type strain DSM 1731. Strain Rh8 can tolerate up to 19 g/L butanol, with solvent titer improved accordingly, thus exhibiting industrial application potential. To test if strain Rh8 can be used for production of high level mixed alcohols, a single secondary alcohol dehydrogenase from Clostridium beijerinckii NRRL B593 was overexpressed in strain Rh8 under the control of thl promoter. Results The heterogenous gene sADH was functionally expressed in C. acetobutylicum Rh8. This simple, one-step engineering approach switched the traditional ABE (acetone-butanol-ethanol) fermentation to IBE (isopropanol-butanol-ethanol) fermentation. The total alcohol titer reached 23.88 g/l (7.6 g/l isopropanol, 15 g/l butanol, and 1.28 g/l ethanol) with a yield to glucose of 31.42%. The acid (butyrate and acetate) assimilation rate in isopropanol producing strain Rh8(psADH) was increased. Conclusions The improved butanol tolerance and the enhanced solvent biosynthesis machinery in strain Rh8 is beneficial for production of high concentration of mixed alcohols. Strain Rh8 can thus be considered as a good host for further engineering of solvent/alcohol production. PMID:22742819

  10. Uptake and Reactions of Formaldehyde, Acetaldehyde, Acetone, Propanal and Ethanol in Sulfuric Acid solutions at 200-240 K: Implications for upper tropospheric aerosol composition

    NASA Astrophysics Data System (ADS)

    Iraci, L. T.; Williams, M. B.; Axson, J.; Michelsen, R.

    2007-12-01

    The production of light absorbing, organic material in aerosol that is normally considered to be transparent in the UV and visible wavelength regions has significant implications for biogeochemical cycling and climate modelling. Production mechanisms likely involve carbonyl compounds such as formaldehyde, acetone, acetaldehyde and propanal that are present in significant quantities in the upper troposphere (UT). In this study, we have performed experiments focusing on a class of acid catalyzed carbonyl reactions, the formation of acetals. R2C=O + 2R'OH --> R2C(OR')2 + H2O Using a Knudsen cell apparatus, we have measured the rate of uptake of formaldehyde, acetaldehyde, acetone, propanal, and ethanol into sulfuric acid solutions ranging between 40-70 wt% of acid, containing 0-0.1 M of ethanol, acetone or formaldehyde at temperatures of 220-250 K. For all reactant pairs, the aldol condensation path, including self reaction, should be insignificant at the acidities studied. Evidence for reaction between organics was observed for all pairs, except those involving propanal which were likely limited by the very low solubility. We attribute enhanced uptake to the formation of acetals, such as 1,1-diethoxyethane and 2,2- diethoxypropane, among others. Enhanced uptake was observed to proceed on timescales > 1 hour and sometimes shows complex dependence on acidity that is likely related to speciation of the individual carbonyls in acidic solution. The acetal products do not absorb in the visible but are less volatile than parent molecules, allowing for accumulation in sulfuric acid particles, and enhanced uptake. Cross reactions of carbonyls with alcohols in sulfuric acid medium have not been previously measured, yet methanol and ethanol show high solubility and are present at significant concentrations in the UT. Thus even at slow reaction rates, the acetal reaction has ample starting material and proceeds under conditions common to the UT. We will present results for the

  11. Butanol production by immobilised Clostridium acetobutylicum in repeated batch, fed-batch, and continuous modes of fermentation.

    PubMed

    Dolejš, Igor; Krasňan, Vladimír; Stloukal, Radek; Rosenberg, Michal; Rebroš, Martin

    2014-10-01

    Clostridium acetobutylicum immobilised in polyvinylalcohol, lens-shaped hydrogel capsules (LentiKats(®)) was studied for production of butanol and other products of acetone-butanol-ethanol fermentation. After optimising the immobilisation protocol for anaerobic bacteria, continuous, repeated batch, and fed-batch fermentations in repeated batch mode were performed. Using glucose as a substrate, butanol productivity of 0.41 g/L/h and solvent productivity of 0.63 g/L/h were observed at a dilution rate of 0.05 h(-1) during continuous fermentation with a concentrated substrate (60 g/L). Through the process of repeated batch fermentation, the duration of fermentation was reduced from 27.8h (free-cell fermentation) to 3.3h (immobilised cells) with a solvent productivity of 0.77 g/L/h (butanol 0.57 g/L/h). The highest butanol and solvent productivities of 1.21 and 1.91 g/L/h were observed during fed-batch fermentation operated in repeated batch mode with yields of butanol (0.15 g/g) and solvents (0.24 g/g), respectively, produced per gram of glucose.

  12. Absorption of ethanol, acetone, benzene and 1,2-dichloroethane through human skin in vitro: a test of diffusion model predictions

    SciTech Connect

    Gajjar, Rachna M.; Kasting, Gerald B.

    2014-11-15

    The overall goal of this research was to further develop and improve an existing skin diffusion model by experimentally confirming the predicted absorption rates of topically-applied volatile organic compounds (VOCs) based on their physicochemical properties, the skin surface temperature, and the wind velocity. In vitro human skin permeation of two hydrophilic solvents (acetone and ethanol) and two lipophilic solvents (benzene and 1,2-dichloroethane) was studied in Franz cells placed in a fume hood. Four doses of each {sup 14}C-radiolabed compound were tested — 5, 10, 20, and 40 μL cm{sup −2}, corresponding to specific doses ranging in mass from 5.0 to 63 mg cm{sup −2}. The maximum percentage of radiolabel absorbed into the receptor solutions for all test conditions was 0.3%. Although the absolute absorption of each solvent increased with dose, percentage absorption decreased. This decrease was consistent with the concept of a stratum corneum deposition region, which traps small amounts of solvent in the upper skin layers, decreasing the evaporation rate. The diffusion model satisfactorily described the cumulative absorption of ethanol; however, values for the other VOCs were underpredicted in a manner related to their ability to disrupt or solubilize skin lipids. In order to more closely describe the permeation data, significant increases in the stratum corneum/water partition coefficients, K{sub sc}, and modest changes to the diffusion coefficients, D{sub sc}, were required. The analysis provided strong evidence for both skin swelling and barrier disruption by VOCs, even by the minute amounts absorbed under these in vitro test conditions. - Highlights: • Human skin absorption of small doses of VOCs was measured in vitro in a fume hood. • The VOCs tested were ethanol, acetone, benzene and 1,2-dichloroethane. • Fraction of dose absorbed for all compounds at all doses tested was less than 0.3%. • The more aggressive VOCs absorbed at higher levels than

  13. Use of poly(ether-block-amide) in pervaporation coupling with a fermentor to enhance butanol production in the cultivation of Clostridium acetobutylicum.

    PubMed

    Yen, Hong-Wei; Lin, Shang-Fu; Yang, I-Kuan

    2012-03-01

    The toxicity of the end-products of acetone-butanol-ethanol (ABE) process, mainly butanol, is recognized as the major problem contributing to the low productivity of butanol. The pervaporation technique was regarded as one of the ways to efficiently remove organic components. The results of pervaporation performance of poly(ether-block-amide) (PEBA) and polydimethylsiloxane (PDMS) membrane in a model solution indicated that PEBA membrane owned a higher butanol permeation flux of 9.975 gm(-2)h(-1) as opposed to 3.911 gm(-2)h(-1) using a PDMS membrane. Moreover, a higher temperature would result in a higher permeation flux, but has a lower separation factor (α) obtained, while using PEBA membrane. The batch fermentor operation connected to the pervaporation with PEBA membrane created 43% and 34% of increase in the butanol productivity and in the yield as compared to that of the simple batch. The fed-batch fermentation mode by glucose feeding combined with PEBA pervaporation lasting for 24h could achieve 39% increase of butanol productivity as compared to a simple batch. Conclusively, the pervaporation with PEBA membrane coupling with fermentor was presumed to be capable of enhancing butanol production in ABE fermentation, which might have the potential applied in the commercialized ABE fermentation process.

  14. Fermentative production of butanol from sorghum molasses as a potential agricultural fuel. Final report, June 26, 1981-September 25, 1982

    SciTech Connect

    Fan, L.T.

    1982-12-01

    A strain, Clostridium acetobutylicum ATCC 4259, suitable for butanol-acetone fermentation of sorghum molasses was selected from several strains of the American Type Culture Collection (ATCC). It was cultivated in the composition-optimized sorghum molasses medium. The microbial growth and sugar consumption pattern in the sorghum molasses medium exhibited a typical diauxie phenomenon. The results strongly suggest that the difficulty encountered by the Weizmann type of organisms in butanol-acetone fermentation of molasses is due to the diauxie phenomenon causing a significant decrease in the solvent production rate. Acid hydrolysis of sorghum molasses minimizes the occurrence of the phenomenon, thereby remarkably increasing the solvent yield. The final solvent concentrations in the inverted molasses medium were butanol, 1.0% (w/v); acetone, 0.37% (w/v); ethanol, 0.18% (w/v); and total solvent, 1.55% (w/v). The total solvent yield in the inverted sorghum molasses medium was 30.3% based on the weight of sugar consumed. Effects of the temperature, agitation and heat-shocking were also investigated.

  15. Cellulosic butanol production from alkali-pretreated switchgrass (Panicum virgatum) and phragmites (Phragmites australis).

    PubMed

    Gao, Kai; Boiano, Simone; Marzocchella, Antonio; Rehmann, Lars

    2014-12-01

    A potential dedicated energy crop (switchgrass) and an invasive (North America) plant species (phragmites) were compared as potential substrates for acetone butanol ethanol (ABE) fermentation. Both biomass were pretreated with 1% (w/v) NaOH and subjected to enzymatic hydrolysis. Total reducing sugar yields were 365 and 385gkg(-1) raw biomass for switchgrass and phragmites. Fermentation of the hydrolysates resulted in overall ABE yields of 146 and 150gkg(-1) (per kg dry plant material), with a theoretical maximum of 189 and 208gkg(-1), respectively. Though similar overall solvent yields were obtained from both crops, the largest carbon loss in the case of switchgrass occurred during pretreatment, while the largest loss in the case of phragmites occurred to enzymatic hydrolysis. These findings suggest that higher overall yields are achievable and that both crops are suitable feedstocks for butanol fermentation.

  16. Atmospheric chemistry of i-butanol.

    PubMed

    Andersen, V F; Wallington, T J; Nielsen, O J

    2010-12-02

    Smog chamber/FTIR techniques were used to determine rate constants of k(Cl + i-butanol) = (2.06 ± 0.40) × 10(-10), k(Cl + i-butyraldehyde) = (1.37 ± 0.08) × 10(-10), and k(OH + i-butanol) = (1.14 ± 0.17) × 10(-11) cm(3) molecule(-1) s(-1) in 700 Torr of N(2)/O(2) diluent at 296 ± 2K. The UV irradiation of i-butanol/Cl(2)/N(2) mixtures gave i-butyraldehyde in a molar yield of 53 ± 3%. The chlorine atom initiated oxidation of i-butanol in the absence of NO gave i-butyraldehyde in a molar yield of 48 ± 3%. The chlorine atom initiated oxidation of i-butanol in the presence of NO gave (molar yields): i-butyraldehyde (46 ± 3%), acetone (35 ± 3%), and formaldehyde (49 ± 3%). The OH radical initiated oxidation of i-butanol in the presence of NO gave acetone in a yield of 61 ± 4%. The reaction of chlorine atoms with i-butanol proceeds 51 ± 5% via attack on the α-position to give an α-hydroxy alkyl radical that reacts with O(2) to give i-butyraldehyde. The atmospheric fate of (CH(3))(2)C(O)CH(2)OH alkoxy radicals is decomposition to acetone and CH(2)OH radicals. The atmospheric fate of OCH(2)(CH(3))CHCH(2)OH alkoxy radicals is decomposition to formaldehyde and CH(3)CHCH(2)OH radicals. The results are consistent with, and serve to validate, the mechanism that has been assumed in the estimation of the photochemical ozone creation potential of i-butanol.

  17. Binary diffusion coefficients for mixtures of ionic liquids [EMIM][N(CN)2], [EMIM][NTf2], and [HMIM][NTf2] with acetone and ethanol by dynamic light scattering (DLS).

    PubMed

    Rausch, Michael H; Hopf, Lisa; Heller, Andreas; Leipertz, Alfred; Fröba, Andreas P

    2013-02-28

    Mutual diffusivities for binary mixtures of the ionic liquids (ILs) [EMIM][N(CN)2] (1-ethyl-3-methylimidazolium dicyanimide), [EMIM][NTf2] (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), and [HMIM][NTf2] (1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) with acetone and ethanol were studied in dependence on composition in the temperature range from 283.15 to 323.15 K, applying dynamic light scattering (DLS). The influence of experimental parameters on the achievable uncertainties was analyzed to ensure the acquisition of accurate data in adequate measurement times. For all probed systems, increasing binary diffusion coefficients were found for increasing temperatures. The systematic variation of anion and cation of the investigated ILs as well as a comparison with the literature data demonstrates the considerable influence of different ions on the resulting binary diffusion coefficients. Mutual diffusivities were found to be lower for the mixtures with ethanol than for those with acetone, which could be related to the formation of hydrogen bonds between ethanol and the ions. Most of the investigated IL solvent mixtures show increasing binary diffusion coefficients with increasing solvent concentration. For the mixtures of [EMIM][NTf2] with ethanol, however, a minimum of the mutual diffusivities was found in the ethanol mole fraction range from 0.7 to 0.8, which may hint at the vicinity of a critical demixing point. The viscosity of the pure ILs turned out to be no reliable indicator for the mutual diffusivity in mixtures with the same solvent.

  18. Enhanced butanol production by coculture of Clostridium beijerinckii and Clostridium tyrobutyricum.

    PubMed

    Li, Lin; Ai, Hongxia; Zhang, Shexi; Li, Shuang; Liang, Zexin; Wu, Zhen-Qiang; Yang, Shang-Tian; Wang, Ju-Fang

    2013-09-01

    Cocultures of Clostridium beijerinckii and Clostridium tyrobutyricum in free-cell and immobilized-cell fermentation modes were investigated as a means of enhancing butanol production. The immobilized fermentation was performed in a fibrous-bed bioreactor (FBB). The results demonstrated that two-strain coculture significantly enhanced butanol production, yield and volumetric productivity compared with those in pure culture with or without butyric acid. Further, continuous immobilized-cell cocultures in two FBBs using glucose, cassava starch, or cane molasses were conducted at a dilution rate of 0.144 h(-1). The butanol production (6.66 g/L), yield (0.18 g/g), and productivity (0.96 g/L/h) were obtained with cassava starch as the substrate. Meanwhile, the acetone-butanol-ethanol (ABE) yield (0.36 g/g) was the highest among all processes investigated, suggesting that this continuous coculture mode may be suitable for industrial ABE production with no need for repeated sterilization and inoculation.

  19. Investigation of gas stripping and pervaporation for improved feasibility of two-stage butanol production process.

    PubMed

    Setlhaku, Mpho; Heitmann, Sebastian; Górak, Andrzej; Wichmann, Rolf

    2013-05-01

    Gas stripping and pervaporation are investigated for butanol recovery in a two-stage acetone-butanol-ethanol (ABE) fermentation process. The first stage is operated in a continuous mode and the second stage as a fed-batch. Gas stripping coupled to the second stage and operated intermittently enabled additional glucose feeding in the second stage and up to 59 g/L butanol and 73 g/L total ABE solvents in the condensate. Concentration of 167 g/L butanol and 269 g/L ABE in the permeate was measured in ex situ pervaporation experiments using a PDMS membrane at temperature of 37 °C and pressure of 10mbars. The "operating window" tool is introduced to evaluate the feasibility of the existing ABE fermentations operated as continuous with cell recycle, as two-stages, with biomass immobilization or with integrated product removal. This tool enables the identification of the most favorable process configuration, which is the combination of cell immobilization and integrated product removal.

  20. Butanol production employing fed-batch fermentation by Clostridium acetobutylicum GX01 using alkali-pretreated sugarcane bagasse hydrolysed by enzymes from Thermoascus aurantiacus QS 7-2-4.

    PubMed

    Pang, Zong-Wen; Lu, Wei; Zhang, Hui; Liang, Zheng-Wu; Liang, Jing-Juan; Du, Liang-Wei; Duan, Cheng-Jie; Feng, Jia-Xun

    2016-07-01

    Sugarcane bagasse (SB) is a potential feedstock for butanol production. However, biological production of butanol from SB is less economically viable. In this study, evaluation of eight pretreatments on SB showed that alkali pretreatment efficiently removed lignin from SB while retaining the intact native structure of the released microfibrils. In total, 99% of cellulose and 100% of hemicellulose in alkali-pretreated SB were hydrolysed by enzymes from Thermoascus aurantiacus. The hydrolysate was used to produce butanol in a fed-batch fermentation by Clostridium acetobutylicum. At 60h, 14.17 and 21.11gL(-1) of butanol and acetone-butanol-ethanol (ABE) were produced from 68.89gL(-1) of total sugars, respectively, yielding 0.22 and 0.33gg(-1) of sugars. The maximum yield of butanol and ABE reached 15.4g and 22.9g per 100g raw SB, respectively. This established process may have potential application for butanol production from SB.

  1. Hybrid Vapor Stripping-Vapor Permeation Process for Recovery and Dehydration of 1-Butanol and Acetone/Butanol/Ethanol from Dilute Aqueous Solutions. Part 2. Experimental Validation with Simple Mixtures and Actual Fermentation Broth

    EPA Science Inventory

    BACKGROUND: In Part1 of this work, a process integrating vapor stripping, vapor compression, and a vapor permeation membrane separation step, Membrane Assisted Vapor Stripping (MAVS), was predicted to produce energy savings compared to traditional distillation systems for separat...

  2. Hydrogen production from oxidative steam reforming of bio-butanol over CoIr-based catalysts: effect of the support.

    PubMed

    Cai, Weijie; Piscina, Pilar Ramírez de la; Gabrowska, Klaudia; Homs, Narcís

    2013-01-01

    This paper studies the influence of the support on the behavior of bimetallic CoIr-based catalysts (6.5 wt.% Co, 0.4 wt.% Ir) for hydrogen production from the oxidative steam reforming of bio-butanol raw mixture (butanol/acetone/ethanol = 6/3/1 mass ratio). Catalytic tests were carried out at 500 °C for 60 h with raw mixture/water/air/Ar = 1/10/7.5/12 molar ratio and GHSV = 7500 h(-1). Over CoIr/18CeZrO(2) and CoIr/ZnO the main process which took place was the oxidative steam reforming of the raw mixture. CoIr/18CeZrO(2) showed the better catalytic performance. Characterization of the used catalysts indicated that both active metal sintering and coke formation was prevented on the CoIr/18CeZrO(2) catalyst.

  3. Hydrogen production from the steam reforming of bio-butanol over novel supported Co-based bimetallic catalysts.

    PubMed

    Cai, Weijie; de la Piscina, Pilar Ramirez; Homs, Narcis

    2012-03-01

    This paper reports the hydrogen production through the steam reforming of a bioresource-derived butanol mixture (butanol:acetone:ethanol=6:3:1 mass ratio) over supported cobalt-based catalysts. The support plays an important role for the catalytic behavior and Co/ZnO exhibits the best catalytic performance compared to Co/TiO(2) and Co/CeO(2). Moreover, a higher hydrogen yield is obtained over bimetallic Co-Ir/ZnO, which shows an increase in H(2) selectivity and a decrease in CH(4) selectivity under steam reforming conditions, compared to Co/ZnO. Raman results of the used catalysts indicate that the addition of Ir could prevent the coke formation to prolong the catalyst stability.

  4. Anaerobic Biodegradation of Biofuels (Ethanol and Biodiesel) and Proposed Biofuels (n-Propanol, iso-Propanol, n-Butanol, and 2,5-Dimethylfuran) in Aquifer Sediments

    EPA Science Inventory

    Biofuels, such as ethanol and biodiesel, are a growing component of the nation’s fuel supply. Ethanol is the primary biofuel in the US market, distributed as a blend with petroleum gasoline, in concentrations ranging from 10% ethanol (E10) to 85% ethanol (E85). Biodiesel, made fr...

  5. Anaerobic Biodegradation of Biofuels (Ethanol and Biodiesel) and Proposed Biofuels (n-Propanol, iso-Propanol, n-Butanol, and 2,5-Dimethylfuran) in Aquifer Sediments

    EPA Science Inventory

    Biofuels, such as ethanol and biodiesel, are a growing component of the nation's fuel supply. Ethanol is the primary biofuel in the US martket, distributed as a blend with petroleum gasoline in concentrations ranging from 10% ethanol (E10) to 85% ethanol (E85). Biodiesel, made ...

  6. Biocatalyzed processes for production of commodity chemicals: Assessment of future research advances for N-butanol production

    NASA Technical Reports Server (NTRS)

    Ingham, J. D.

    1984-01-01

    This report is a summary of assessments by Chem Systems Inc. and a further evaluation of the impacts of research advances on energy efficiency and the potential for future industrial production of acetone-butanol-ethanol (ABE) solvents and other products by biocatalyzed processes. Brief discussions of each of the assessments made by CSI, followed by estimates of minimum projected energy consumption and costs for production of solvents by ABE biocatalyzed processes are included. These assessments and further advances discussed in this report show that substantial decreases in energy consumption and costs are possible on the basis of specific research advances; therefore, it appears that a biocatalyzed process for ABE can be developed that will be competitive with conventional petrochemical processes for production of n-butanol and acetone. (In this work, the ABE process was selected and utilized only as an example for methodology development; other possible bioprocesses for production of commodity chemicals are not intended to be excluded.) It has been estimated that process energy consumption can be decreased by 50%, with a corresponding cost reduction of 15-30% (in comparison with a conventional petrochemical process) by increasing microorganism tolerance to n-butanol and efficient recovery of product solvents from the vapor phase.

  7. Butanol production from renewable biomass by clostridia.

    PubMed

    Jang, Yu-Sin; Malaviya, Alok; Cho, Changhee; Lee, Joungmin; Lee, Sang Yup

    2012-11-01

    Global energy crisis and limited supply of petroleum fuels have rekindled the worldwide focus towards development of a sustainable technology for alternative fuel production. Utilization of abundant renewable biomass offers an excellent opportunity for the development of an economical biofuel production process at a scale sufficiently large to have an impact on sustainability and security objectives. Additionally, several environmental benefits have also been linked with the utilization of renewable biomass. Butanol is considered to be superior to ethanol due to its higher energy content and less hygroscopy. This has led to an increased research interest in butanol production from renewable biomass in recent years. In this paper, we review the various aspects of utilizing renewable biomass for clostridial butanol production. Focus is given on various alternative substrates that have been used for butanol production and on fermentation strategies recently reported to improve butanol production.

  8. Metabolic engineering of Escherichia coli for 1-butanol production.

    PubMed

    Atsumi, Shota; Cann, Anthony F; Connor, Michael R; Shen, Claire R; Smith, Kevin M; Brynildsen, Mark P; Chou, Katherine J Y; Hanai, Taizo; Liao, James C

    2008-11-01

    Compared to ethanol, butanol offers many advantages as a substitute for gasoline because of higher energy content and higher hydrophobicity. Typically, 1-butanol is produced by Clostridium in a mixed-product fermentation. To facilitate strain improvement for specificity and productivity, we engineered a synthetic pathway in Escherichia coli and demonstrated the production of 1-butanol from this non-native user-friendly host. Alternative genes and competing pathway deletions were evaluated for 1-butanol production. Results show promise for using E. coli for 1-butanol production.

  9. Continuous butanol fermentation and feed starch retrogradation: butanol fermentation sustainability using Clostridium beijerinckii BA101.

    PubMed

    Ezeji, T C; Qureshi, N; Blaschek, H P

    2005-01-26

    Use of starch solution as feed for butanol bioconversion processes employing Clostridium beijerinckii BA101 may have added economic advantage over the use of glucose. Acetone butanol ethanol (ABE) was produced from 30 gL(-1) starch solution using a continuous process. The bioreactor was fed at a dilution rate of 0.02 h(-1) and starch solution/feed volume (3 L) was replaced every 72 h. The continuous reactor fed with cornstarch solution (feed temperature 19 degrees C) produced approximately 6.0 gL(-1) total ABE. Increasing the feed storage temperature to 37 degrees C improved ABE production to 7.2 gL(-1) suggesting that retrogradation was occurring more rapidly at 19 degrees C. In both these cases the fermentation drifted toward acid production after approximately 260 h, consistent with the retrogradation of starch overtime. The use of soluble starch, which is less prone to retrogradation, resulted in the production of 9.9 gL(-1) ABE at 37 degrees C feed storage temperature, as compared to 7.2 gL(-1) ABE when cornstarch was used. It should be noted that gelatinized starch retrogradation takes place after sterilization and prior to use of the feed medium, and does not occur during long-term storage of the raw corn material in the months leading up to processing. The degree of hydrolysis of gelatinized starch decreased from 68.8 to 56.2% in 3 days when stored at 37 degrees C. Soluble starch which does not retrograde demonstrated no change in the degree of hydrolysis.

  10. Development of a High-Efficiency Transformation Method and Implementation of Rational Metabolic Engineering for the Industrial Butanol Hyperproducer Clostridium saccharoperbutylacetonicum Strain N1-4.

    PubMed

    Herman, Nicolaus A; Li, Jeffrey; Bedi, Ripika; Turchi, Barbara; Liu, Xiaoji; Miller, Michael J; Zhang, Wenjun

    2017-01-15

    While a majority of academic studies concerning acetone, butanol, and ethanol (ABE) production by Clostridium have focused on Clostridium acetobutylicum, other members of this genus have proven to be effective industrial workhorses despite the inability to perform genetic manipulations on many of these strains. To further improve the industrial performance of these strains in areas such as substrate usage, solvent production, and end product versatility, transformation methods and genetic tools are needed to overcome the genetic intractability displayed by these species. In this study, we present the development of a high-efficiency transformation method for the industrial butanol hyperproducer Clostridium saccharoperbutylacetonicum strain N1-4 (HMT) ATCC 27021. Following initial failures, we found that the key to creating a successful transformation method was the identification of three distinct colony morphologies (types S, R, and I), which displayed significant differences in transformability. Working with the readily transformable type I cells (transformation efficiency, 1.1 × 10(6) CFU/μg DNA), we performed targeted gene deletions in C. saccharoperbutylacetonicum N1-4 using a homologous recombination-mediated allelic exchange method. Using plasmid-based gene overexpression and targeted knockouts of key genes in the native acetone-butanol-ethanol (ABE) metabolic pathway, we successfully implemented rational metabolic engineering strategies, yielding in the best case an engineered strain (Clostridium saccharoperbutylacetonicum strain N1-4/pWIS13) displaying an 18% increase in butanol titers and 30% increase in total ABE titer (0.35 g ABE/g sucrose) in batch fermentations. Additionally, two engineered strains overexpressing aldehyde/alcohol dehydrogenases (encoded by adh11 and adh5) displayed 8.5- and 11.8-fold increases (respectively) in batch ethanol production.

  11. Cell growth behaviors of Clostridium acetobutylicum in a pervaporation membrane bioreactor for butanol fermentation.

    PubMed

    Yao, Peina; Xiao, Zeyi; Chen, Chunyan; Li, Weijia; Deng, Qing

    2016-01-01

    Acetone-butanol-ethanol fermentation using Clostridium acetobutylicum was studied in the continuous and closed-circulating fermentation (CCCF) system. The experiment lasting for 192 H was carried out by integrating fermentation with in situ pervaporation. In the entire process, the cell growth profile took place in the following two phases: the logarithmic phase during early 28 H and the linear phase from 130 to 150 H. This was a unique characteristic compared with the curve of traditional fermentation, and the fitting equations of two growth phases were obtained by Origin software according to the kinetic model of cell growth. Besides, the kinetic parameters that include the butanol yield, maximum specific growth rate, average specific formation rate, and volumetric productivity of butanol were measured as 0.19 g g(-1) , 0.345 H(-1) , 0.134 H(-1) and 0.23 g L(-1)  H(-1) , respectively. The C. acetobutylicum in the CCCF system showed good adaptability and fermentation performance, and the prolonged fermentation period and high production were also the main advantages of CCCF technology.

  12. Comparative shotgun proteomic analysis of Clostridium acetobutylicum from butanol fermentation using glucose and xylose

    PubMed Central

    2011-01-01

    Background Butanol is a second generation biofuel produced by Clostridium acetobutylicum through acetone-butanol-ethanol (ABE) fermentation process. Shotgun proteomics provides a direct approach to study the whole proteome of an organism in depth. This paper focuses on shotgun proteomic profiling of C. acetobutylicum from ABE fermentation using glucose and xylose to understand the functional mechanisms of C. acetobutylicum proteins involved in butanol production. Results We identified 894 different proteins in C. acetobutylicum from ABE fermentation process by two dimensional - liquid chromatography - tandem mass spectrometry (2D-LC-MS/MS) method. This includes 717 proteins from glucose and 826 proteins from the xylose substrate. A total of 649 proteins were found to be common and 22 significantly differentially expressed proteins were identified between glucose and xylose substrates. Conclusion Our results demonstrate that flagellar proteins are highly up-regulated with glucose compared to xylose substrate during ABE fermentation. Chemotactic activity was also found to be lost with the xylose substrate due to the absence of CheW and CheV proteins. This is the first report on the shotgun proteomic analysis of C. acetobutylicum ATCC 824 in ABE fermentation between glucose and xylose substrate from a single time data point and the number of proteins identified here is more than any other study performed on this organism up to this report. PMID:22008648

  13. Butanol production from wood pulping hydrolysate in an integrated fermentation-gas stripping process

    SciTech Connect

    Lu, CC; Dong, J; Yang, ST

    2013-09-01

    Wood pulping hydrolysate (WPH) containing mainly xylose and glucose as a potential substrate for acetone-butanol-ethanol (ABE) fermentation was studied. Due to the inhibitors present in the hydrolysate, several dilution levels and detoxification treatments, including overliming, activated charcoal adsorption, and resin adsorption, were evaluated for their effectiveness in relieving the inhibition on fermentation. Detoxification using resin and evaporation was found to be the most effective method in reducing the toxicity of WPH. ABE production in batch fermentation by Clostridium beijerinckii increased 68%, from 6.73 g/L in the non-treated and non-diluted WPH to 11.35 g/L in the resin treated WPH. With gas stripping for in situ product removal, ABE production from WPH increased to 17.73 g/L, demonstrating that gas stripping was effective in alleviating butanol toxicity by selectively separating butanol from the fermentation broth, which greatly improved solvents production and sugar conversion in the fermentation. (C) 2013 Elsevier Ltd. All rights reserved.

  14. Phenotypic characterisation of Saccharomyces spp. for tolerance to 1-butanol.

    PubMed

    Zaki, A M; Wimalasena, T T; Greetham, D

    2014-11-01

    Biofuels are expected to play a role in replacing crude oil as a liquid transportation fuel, and research into butanol has highlighted the importance of this alcohol as a fuel. Butanol has a higher energy density than ethanol, butanol-gasoline blends do not separate in the presence of water, and butanol is miscible with gasoline (Szulczyk, Int J Energy Environ 1(1):2876-2895, 40). Saccharomyces cerevisiae has been used as a fermentative organism in the biofuel industry producing ethanol from glucose derived from starchy plant material; however, it typically cannot tolerate butanol concentrations greater than 2 % (Luong, Biotechnol Bioeng 29 (2):242-248, 27). 90 Saccharomyces spp. strains were screened for tolerance to 1-butanol via a phenotypic microarray assay and we observed significant variation in response with the most tolerant strains (S. cerevisiae DBVPG1788, S. cerevisiae DBVPG6044 and S. cerevisiae YPS128) exhibiting tolerance to 4 % 1-butanol compared with S. uvarum and S. castelli strains, which were sensitive to 3 % 1-butanol. Response to butanol was confirmed using traditional yeast methodologies such as growth; it was observed that fermentations in the presence of butanol, when using strains with a tolerant background, were significantly faster. Assessing for genetic rationale for tolerance, it was observed that 1-butanol-tolerant strains, when compared with 1-butanol-sensitive strains, had an up-regulation of RPN4, a transcription factor which regulates proteasome genes. Analysing for the importance of RPN4, we observed that a Δrpn4 strain displayed a reduced rate of fermentation in the presence of 1-butanol when compared with the BY4741 background strain. This data will aid the development of breeding programmes to produce better strains for future bio-butanol production.

  15. Macroalgae Butanol

    SciTech Connect

    2010-02-01

    Broad Funding Opportunity Announcement Project: E. I. du Pont de Nemours & Company (DuPont) and Bio Architecture Lab, Inc. (BAL) are exploring the commercial viability of producing fuel-grade isobutanol from macroalgae (seaweed). Making macroalgae an attractive substrate for biofuel applications however, will require continued technology development. Assuming these developments are successful, initial assessments suggest macroalgae aquafarming in our oceans has the potential to produce a feedstock with cost in the same range as terrestrial-based substrates (crop residuals, energy crops) and may be the feedstock of choice in some locations. The use of macroalgae also diversifies the sources of U.S. biomass in order to provide more options in meeting demand for biofuels. The process being developed will use a robust industrial biocatalyst (microorganism) capable of converting macroalgal-derived sugars directly into isobutanol. Biobutanol is an advanced biofuel with significant advantages over ethanol, including higher energy content, lower greenhouse gas emissions, and the ability to be blended in gasoline at higher levels than ethanol without changes to existing automobiles or the fuel industry infrastructure. Butamax™ is currently commercializing DuPont’s biobutanol fermentation technology that uses sugar and starch feedstocks.

  16. Study of in situ 1-butanol pervaporation from A-B-E fermentation using a PDMS composite membrane: validity of solution-diffusion model for pervaporative A-B-E fermentation.

    PubMed

    Li, Si-Yu; Srivastava, Ranjan; Parnas, Richard S

    2011-01-01

    In this study, the application of a new polydimethylsiloxane (PDMS)/dual support composite membrane was investigated by incorporating the pervaporation process into the A-B-E (acetone-butanol-ethanol) fermentation. The performance of the A-B-E fermentation using the integrated pervaporation/fermentation process showed higher biomass concentrations and higher glucose consumption rates than those of the A-B-E fermentation without pervaporation. The performance of the membrane separation was studied during the separation of 1-butanol from three different 1-butanol solutions: binary, model, and fermentation culture solutions. The solution-diffusion model, specifically the mass transfer equation based on Fick's First Law, was shown to be applicable to the undefined A-B-E fermentation culture solutions. A quantitative comparison of 1-butanol separation from the three different solutions was made by calculating overall mass transfer coefficients of 1-butanol. It was found that the overall mass transfer coefficients during the separation of binary, model, and fermentation culture solutions were 1.50, 1.26, and 1.08 mm/h, respectively.

  17. Modifying the product pattern of Clostridium acetobutylicum: physiological effects of disrupting the acetate and acetone formation pathways.

    PubMed

    Lehmann, Dörte; Hönicke, Daniel; Ehrenreich, Armin; Schmidt, Michael; Weuster-Botz, Dirk; Bahl, Hubert; Lütke-Eversloh, Tina

    2012-05-01

    Clostridial acetone-butanol-ethanol (ABE) fermentation is a natural source for microbial n-butanol production and regained much interest in academia and industry in the past years. Due to the difficult genetic accessibility of Clostridium acetobutylicum and other solventogenic clostridia, successful metabolic engineering approaches are still rare. In this study, a set of five knock-out mutants with defects in the central fermentative metabolism were generated using the ClosTron technology, including the construction of targeted double knock-out mutants of C. acetobtuylicum ATCC 824. While disruption of the acetate biosynthetic pathway had no significant impact on the metabolite distribution, mutants with defects in the acetone pathway, including both acetoacetate decarboxylase (Adc)-negative and acetoacetyl-CoA:acyl-CoA transferase (CtfAB)-negative mutants, exhibited high amounts of acetate in the fermentation broth. Distinct butyrate increase and decrease patterns during the course of fermentations provided experimental evidence that butyrate, but not acetate, is re-assimilated via an Adc/CtfAB-independent pathway in C. acetobutylicum. Interestingly, combining the adc and ctfA mutations with a knock-out of the phosphotransacetylase (Pta)-encoding gene, acetate production was drastically reduced, resulting in an increased flux towards butyrate. Except for the Pta-negative single mutant, all mutants exhibited a significantly reduced solvent production.

  18. Butanol production from wheat straw hydrolysate using Clostridium beijerinckii.

    PubMed

    Qureshi, Nasib; Saha, Badal C; Cotta, Michael A

    2007-11-01

    In these studies, butanol (acetone butanol ethanol or ABE) was produced from wheat straw hydrolysate (WSH) in batch cultures using Clostridium beijerinckii P260. In control fermentation 48.9 g L(-1) glucose (initial sugar 62.0 g L(-1)) was used to produce 20.1 g L(-1) ABE with a productivity and yield of 0.28 g L(-1 )h(-1) and 0.41, respectively. In a similar experiment where WSH (60.2 g L(-1) total sugars obtained from hydrolysis of 86 g L(-1) wheat straw) was used, the culture produced 25.0 g L(-1) ABE with a productivity and yield of 0.60 g L(-1 )h(-1) and 0.42, respectively. These results are superior to the control experiment and productivity was improved by 214%. When WSH was supplemented with 35 g L(-1) glucose, a reactor productivity was improved to 0.63 g L(-1 )h(-1) with a yield of 0.42. In this case, ABE concentration in the broth was 28.2 g L(-1). When WSH was supplemented with 60 g L(-1) glucose, the resultant medium containing 128.3 g L(-1) sugars was successfully fermented (due to product removal) to produce 47.6 g L(-1) ABE, and the culture utilized all the sugars (glucose, xylose, arabinose, galactose, and mannose). These results demonstrate that C. beijerinckii P260 has excellent capacity to convert biomass derived sugars to solvents and can produce over 28 g L(-1) (in one case 41.7 g L(-1) from glucose) ABE from WSH. Medium containing 250 g L(-1) glucose resulted in no growth and no ABE production. Mixtures containing WSH + 140 g L(-1) glucose (total sugar approximately 200 g L(-1)) showed poor growth and poor ABE production.

  19. Economic evaluation of the acetone-butane fermentation

    SciTech Connect

    Lenz, T.G.; Moreira, A.R.

    1980-01-01

    The economics of producing acetone as 1-butanol via fermentation have been examined for a 45 x 1 kg of solvents/year plant. For a molasses substrate the total annual production costs were approximately $39 million vs. a total annual income of $36 million, with approximatley $20 million total required capital. Molasses cost of approximately $24.4 million/year was critical to these economics. Liquid whey was next evaluated as an alternative feed. Whey feed saved approximately 11 million dollars annually in feed costs and yielded approximately 8 million net additional annual revenues from protein sale. The primary differences gave an annual gross profit of approximately $15 million for the whey case and resulted in a discounted cash flow rate return of 29%. Waste-based acetone-butanol production via fermentation deserves further attention in view of the attractive whey-based economics and the excellent potential of butanol as a fuel extender, especially for diesohol blending.

  20. Butanol production from concentrated lactose/whey permeate: use of pervaporation membrane to recover and concentrate product.

    PubMed

    Qureshi, N; Friedl, A; Maddox, I S

    2014-12-01

    In these studies, butanol (acetone butanol ethanol or ABE) was produced from concentrated lactose/whey permeate containing 211 g L(-1) lactose. Fermentation of such a highly concentrated lactose solution was possible due to simultaneous product removal using a pervaporation membrane. In this system, a productivity of 0.43 g L(-1) h(-1) was obtained which is 307 % of that achieved in a non-product removal batch reactor (0.14 g L(-1) h(-1)) where approximately 60 g L(-1) whey permeate lactose was fermented. The productivity obtained in this system is much higher than that achieved in other product removal systems (perstraction 0.21 g L(-1) h(-1) and gas stripping 0.32 g L(-1) h(-1)). This membrane was also used to concentrate butanol from approximately 2.50 g L(-1) in the reactor to 755 g L(-1). Using this membrane, ABE selectivities and fluxes of 24.4-44.3 and 0.57-4.05 g m(-2) h(-1) were obtained, respectively. Pervaporation restricts removal of water from the reaction mixture thus requiring significantly less energy for product recovery when compared to gas stripping.

  1. Chemostat cultivation and transcriptional analyses of Clostridium acetobutylicum mutants with defects in the acid and acetone biosynthetic pathways.

    PubMed

    Hönicke, Daniel; Lütke-Eversloh, Tina; Liu, Ziyong; Lehmann, Dörte; Liebl, Wolfgang; Ehrenreich, Armin

    2014-12-01

    Clostridium acetobutylicum is a model organism for the biotechnologically important acetone-butanol-ethanol (ABE) fermentation. With the objective to rationally develop strains with improved butanol production, detailed insights into the physiological and genetic mechanisms of solvent production are required. Therefore, pH-controlled phosphate-limited chemostat cultivation and DNA microarray technology were employed for an in-depth analysis of knockout mutants with defects in the central fermentative metabolism. The set of studied mutants included strains with inactivated phosphotransacetylase (pta), phosphotransbutyrylase (ptb), and acetoacetate decarboxylase (adc) encoding genes, as well as an adc/pta double knockout mutant. A comprehensive physiological characterization of the mutants was performed by continuous cultivation, allowing for a well-defined separation of acidogenic and solventogenic growth, combined with the advantage of the high reproducibility of steady-state conditions. The ptb-negative strain C. acetobutylicum ptb::int(87) exhibited the most striking metabolite profile: Sizable amounts of butanol (29 ± 1.3 mM) were already produced during acidogenic growth. The product patterns of the mutants as well as accompanying transcriptomic data are presented and discussed.

  2. Ethanol stimulates epithelial sodium channels by elevating reactive oxygen species.

    PubMed

    Bao, Hui-Fang; Song, John Z; Duke, Billie J; Ma, He-Ping; Denson, Donald D; Eaton, Douglas C

    2012-12-01

    Alcohol affects total body sodium balance, but the molecular mechanism of its effect remains unclear. We used single-channel methods to examine how ethanol affects epithelial sodium channels (ENaC) in A6 distal nephron cells. The data showed that ethanol significantly increased both ENaC open probability (P(o)) and the number of active ENaC in patches (N). 1-Propanol and 1-butanol also increased ENaC activity, but iso-alcohols did not. The effects of ethanol were mimicked by acetaldehyde, the first metabolic product of ethanol, but not by acetone, the metabolic product of 2-propanol. Besides increasing open probability and apparent density of active channels, confocal microscopy and surface biotinylation showed that ethanol significantly increased α-ENaC protein in the apical membrane. The effects of ethanol on ENaC P(o) and N were abolished by a superoxide scavenger, 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy (TEMPOL) and blocked by the phosphatidylinositol 3-kinase inhibitor LY294002. Consistent with an effect of ethanol-induced reactive oxygen species (ROS) on ENaC, primary alcohols and acetaldehyde elevated intracellular ROS, but secondary alcohols did not. Taken together with our previous finding that ROS stimulate ENaC, the current results suggest that ethanol stimulates ENaC by elevating intracellular ROS probably via its metabolic product acetaldehyde.

  3. Butanol production from hexoses and pentoses by fermentation of Clostridium acetobutylicum.

    PubMed

    Raganati, Francesca; Olivieri, Giuseppe; Götz, Peter; Marzocchella, Antonio; Salatino, Piero

    2015-08-01

    The present paper reports the characterization of ABE (acetone-butanol-ethanol) production by Clostridium acetobutylicum DSM 792 for sugars representative of hydrolysed lignocellulosic biomass (glucose, mannose, arabinose, xylose). The attention was focused on: the selection of an optimal medium for the simultaneous conversion of the investigated sugars; the assessment of interference-synergistic effects during the fermentation of mixtures of the investigated sugars. The synthetic medium was optimised in terms of nutritional factors: the KH2PO4-K2HPO4 concentration was increased up to 5 g/L; the MgSO4 concentration was increased up to 2 g/L; the MnSO4 concentration was increased up to 0.1 g/L; the FeSO4 concentration ranged between 0.002 and 0.01 g/L); the CaCO3 concentration was increased up to 10 g/L. The optimal concentration of the investigated factors was assessed and it varied from one sugar to another. The batch fermentations of a mixture of the four sugars highlighted their synergistic effects. Once set the initial concentration of the sugars (60 g/L), the butanol and solvent concentration increased up to 14.6 and 20.6 g/L, respectively, when the four sugars were present.

  4. Improved efficiency of separate hexose and pentose fermentation from steam-exploded corn stalk for butanol production using Clostridium beijerinckii.

    PubMed

    Mu, Xindong; Sun, Wei; Liu, Chao; Wang, Haisong

    2011-08-01

    Water extract of steam-exploded corn stalk (SECS) was detoxified and used as feed for acetone-butanol-ethanol (ABE) fermentation using Clostridium beijerinckii. Utilization of water extract improved the total ABE yield (g ABE/g dry SECS). Separated fermentation showed higher fermentability (0.078 g ABE/g dry SECS) over typical fermentation (0.058 g ABE/g dry SECS). Furthermore, the final ABE yields (g ABE/g utilized sugar) from water extract neutralized by Ca(OH)(2), NaOH, and Na(2)SO(3) were 0.16, 0.1 and 0.07, respectively, suggesting that Ca(OH)(2) had the best detoxification effect.

  5. Synthetic resin-bound truncated Candida antarctica lipase B for production of fatty acid alkyl esters by transesterification of corn and soybean oils with ethanol or butanol.

    PubMed

    Hughes, Stephen R; Moser, Bryan R; Robinson, Samantha; Cox, Elby J; Harmsen, Amanda J; Friesen, Jon A; Bischoff, Kenneth M; Jones, Marjorie A; Pinkelman, Rebecca; Bang, Sookie S; Tasaki, Ken; Doll, Kenneth M; Qureshi, Nasib; Liu, Siqing; Saha, Badal C; Jackson, John S; Cotta, Michael A; Rich, Joseph O; Caimi, Paolo

    2012-05-31

    A gene encoding a synthetic truncated Candida antarctica lipase B (CALB) was generated via automated PCR and expressed in Saccharomyces cerevisiae. Western blot analysis detected five truncated CALB variants, suggesting multiple translation starts from the six in-frame ATG codons. The longest open reading frame, which corresponds to amino acids 35-317 of the mature lipase, appeared to be expressed in the greatest amount. The truncated CALB was immobilized on Sepabeads® EC-EP resin and used to produce ethyl and butyl esters from crude corn oil and refined soybean oil. The yield of ethyl esters was 4-fold greater from corn oil than from soybean oil and was 36% and 50% higher, respectively, when compared to a commercially available lipase resin (Novozym 435) using the same substrates. A 5:1 (v/v) ratio of ethanol to corn oil produced 3.7-fold and 8.4-fold greater yields than ratios of 15:1 and 30:1, respectively. With corn oil, butyl ester production was 56% higher than ethyl ester production. Addition of an ionic catalytic resin step prior to the CALB resin increased yields of ethyl esters from corn oil by 53% compared to CALB resin followed by ionic resin. The results suggest resin-bound truncated CALB has potential application in biodiesel production using biocatalysts.

  6. Technoeconomic evaluation of the extractive fermentation of butanol as a guide to research in this area of biotechnology

    SciTech Connect

    Busche, R.M. )

    1991-09-01

    This report represents the completion of a part of an overall project to evaluate the technical and economic status of several newly conceptualized processes for producing butanol, acetone, acetic acid, and aerobically produced specialty chemicals, which are candidates for research support. The objective of the project are to identify strengths and weaknesses in the proposed and to assist in developing an ongoing research strategy along economically relevant lines. The products to be studied presently comprise a collective US market for 10.7 billion lb valued at $2.8 billion. If their manufacturing processes were converted from petroleum feedstocks to corn, they could consume 556 million bushels. Furthermore, if ethanol could be produced at a low enough price to serve as the precursor to ethylene and butadiene, it an its derivatives could account for 159 billion lb, or 50% of the US production of 316 billion lb of synthetic organic chemicals, presently valued at $113 billion. This use would consume 3.4 billion bushels, or {approximately}45% of the corn crop. In addition, the use of butanol for diesel blends or in jet fuel blends to enhance the range of military aircraft could further increase its market.

  7. Process integration for simultaneous saccharification, fermentation, and recovery (SSFR): production of butanol from corn stover using Clostridium beijerinckii P260.

    PubMed

    Qureshi, N; Singh, V; Liu, S; Ezeji, T C; Saha, B C; Cotta, M A

    2014-02-01

    A simultaneous saccharification, fermentation, and recovery (SSFR) process was developed for the production of acetone-butanol-ethanol (AB or ABE), of which butanol is the main product, from corn stover employing Clostridium beijerinckii P260. Of the 86 g L(-1) corn stover provided, over 97% of the sugars were released during hydrolysis and these were fermented completely with an ABE productivity of 0.34 g L(-1)h(-1) and yield of 0.39. This productivity is higher than 0.31 g L(-1)h(-1) when using glucose as a substrate demonstrating that AB could be produced efficiently from lignocellulosic biomass. Acetic acid that was released from the biomass during pretreatment and hydrolysis was also used by the culture to produce AB. An average rate of generation of sugars during corn stover hydrolysis was 0.98 g L(-1)h(-1). In this system AB was recovered using vacuum, and as a result of this (simultaneous product recovery), 100% sugars were used by the culture.

  8. Reduction of acetone to isopropanol using producer gas fermenting microbes.

    PubMed

    Ramachandriya, Karthikeyan D; Wilkins, Mark R; Delorme, Marthah J M; Zhu, Xiaoguang; Kundiyana, Dimple K; Atiyeh, Hasan K; Huhnke, Raymond L

    2011-10-01

    Gasification-fermentation is an emerging technology for the conversion of lignocellulosic materials into biofuels and specialty chemicals. For effective utilization of producer gas by fermenting bacteria, tar compounds produced in the gasification process are often removed by wet scrubbing techniques using acetone. In a preliminary study using biomass generated producer gas scrubbed with acetone, an accumulation of acetone and subsequent isopropanol production was observed. The effect of 2 g/L acetone concentrations in the fermentation media on growth and product distributions was studied with "Clostridium ragsdalei," also known as Clostridium strain P11 or P11, and Clostridium carboxidivorans P7 or P7. The reduction of acetone to isopropanol was possible with "C. ragsdalei," but not with P7. In P11 this reaction occurred rapidly when acetone was added in the acidogenic phase, but was 2.5 times slower when added in the solventogenic phase. Acetone at concentrations of 2 g/L did not affect the growth of P7, but ethanol increased by 41% and acetic acid concentrations decreased by 79%. In the fermentations using P11, growth was unaffected and ethanol concentrations increased by 55% when acetone was added in the acidogenic phase. Acetic acid concentrations increased by 19% in both the treatments where acetone was added. Our observations indicate that P11 has a secondary alcohol dehydrogenase that enables it to reduce acetone to isopropanol, while P7 lacks this enzyme. P11 offers an opportunity for biological production of isopropanol from acetone reduction in the presence of gaseous substrates (CO, CO₂, and H₂).

  9. Prospects for Anaerobic Biodegradation of Biofuels (Ethanol and Biodiesel) and Proposed Biofuels (n-Propanol, iso-Propanol, n-Butanol, and 2,5-Dimethylfuran) in Aquifer Sediments

    EPA Science Inventory

    Biofuels, such as ethanol and biodiesel, are a growing component of the nation’s fuel supply. Ethanol is the primary biofuel in the US market, distributed as a blend with petroleum gasoline, in concentrations ranging from 10% ethanol (E10) to 85% ethanol (E85). Biodiesel, made ...

  10. n-Butanol

    Integrated Risk Information System (IRIS)

    n - Butanol ; CASRN 71 - 36 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  11. Butanol tolerance in microorganisms

    DOEpatents

    Bramucci, Michael G.; Nagarajan, Vasantha

    2016-03-01

    Provided herein are recombinant yeast host cells and methods for their use for production of fermentation products from a pyruvate utilizing pathway. Yeast host cells provided herein comprise reduced pyruvate decarboxylase activity and modified adenylate cyclase activity. In embodiments, yeast host cells provided herein comprise resistance to butanol and increased biomass production.

  12. Improvement of butanol production from a hardwood hemicelluloses hydrolysate by combined sugar concentration and phenols removal.

    PubMed

    Mechmech, Fatma; Chadjaa, Hassan; Rahni, Mohamed; Marinova, Mariya; Ben Akacha, Najla; Gargouri, Mohamed

    2015-09-01

    The feasibility of using hardwood hemicellulosic pre-hydrolysate recovered from a dissolving pulping process for Acetone-Butanol-Ethanol (ABE) fermentation has been investigated. Dilutions and detoxification methods based on flocculation and nanofiltration were tested to determine the inhibitory concentration of phenolic compounds and to evaluate the efficiency of inhibitors removal on fermentation. Flocculation carried out with ferric sulfate was the most effective method for removal of phenolics (56%) and acetic acid (80%). The impact on fermentation was significant, with an ABE production of 6.40 g/L and 4.25 g/L when using flocculation or combined nanofiltration/flocculation respectively, as compared to a non-significant production for the untreated hydrolysate. By decreasing the toxicity effect of inhibitors, this study reports for the first time that the use of these techniques is efficient to increase the inhibitory concentration threshold of phenols, from 0.3g/L in untreated hydrolysate, to 1.1g/L in flocculated and in nanofiltrated and flocculated hydrolysates.

  13. Butanol production from lignocellulose by simultaneous fermentation, saccharification, and pervaporation or vacuum evaporation.

    PubMed

    Díaz, Víctor Hugo Grisales; Tost, Gerard Olivar

    2016-10-01

    Techno-economic study of acetone, butanol and ethanol (ABE) fermentation from lignocellulose was performed. Simultaneous saccharification, fermentation and vacuum evaporation (SFS-V) or pervaporation (SFS-P) were proposed. A kinetic model of metabolic pathways for ABE fermentation with the effect of phenolics and furans in the growth was proposed based on published laboratory results. The processes were optimized in Matlab®. The end ABE purification was carried out by heat-integrated distillation. The objective function of the minimization was the total annualized cost (TAC). Fuel consumption of SFS-P using poly[1-(trimethylsilyl)-1-propyne] membrane was between 13.8 and 19.6% lower than SFS-V. Recovery of furans and phenolics for the hybrid reactors was difficult for its high boiling point. TAC of SFS-P was increased 1.9 times with supplementation of phenolics and furans to 3g/l each one for its high toxicity. Therefore, an additional detoxification method or an efficient pretreatment process will be necessary.

  14. Oil palm empty fruit bunch to biofuels and chemicals via SO2-ethanol-water fractionation and ABE fermentation.

    PubMed

    Sklavounos, Evangelos; Iakovlev, Mikhail; Survase, Shrikant; Granström, Tom; van Heiningen, Adriaan

    2013-11-01

    A process has been developed for conversion of spent liquor produced by SO2-ethanol-water (SEW) fractionation of oil palm empty fruit bunch (OPEFB) fibers to biofuels by ABE fermentation. The fermentation process utilizes Clostridia bacteria that produce butanol, ethanol and acetone solvents at a total yield of 0.26 g/g sugars. A conditioning scheme is developed, which demonstrates that it is possible to utilize the hemicellulose sugars from this agricultural waste stream by traditional ABE fermentation. Fractionation as well as sugar hydrolysis in the spent liquor is hindered by the high cation content of OPEFB, which can be partly removed by acidic leaching suggesting that a better deashing method is necessary. Furthermore, it is inferred that better and more selective lignin removal is needed during conditioning to improve liquor fermentability.

  15. In Vitro Bioconversion of Pyruvate to n-Butanol with Minimized Cofactor Utilization

    PubMed Central

    Reiße, Steven; Haack, Martina; Garbe, Daniel; Sommer, Bettina; Steffler, Fabian; Carsten, Jörg; Bohnen, Frank; Sieber, Volker; Brück, Thomas

    2016-01-01

    Due to enhanced energy content and reduced hygroscopicity compared with ethanol, n-butanol is flagged as the next generation biofuel and platform chemical. In addition to conventional cellular systems, n-butanol bioproduction by enzyme cascades is gaining momentum due to simplified process control. In contrast to other bio-based alcohols like ethanol and isobutanol, cell-free n-butanol biosynthesis from the central metabolic intermediate pyruvate involves cofactors [NAD(P)H, CoA] and acetyl-CoA-dependent intermediates, which complicates redox and energy balancing of the reaction system. We have devised a biochemical process for cell-free n-butanol production that only involves three enzyme activities, thereby eliminating the need for acetyl-CoA. Instead, the process utilizes only NADH as the sole redox mediator. Central to this new process is the amino acid catalyzed enamine–aldol condensation, which transforms acetaldehyde directly into crotonaldehyde. Subsequently, crotonaldehyde is reduced to n-butanol applying a 2-enoate reductase and an alcohol dehydrogenase, respectively. In essence, we achieved conversion of the platform intermediate pyruvate to n-butanol utilizing a biocatalytic cascade comprising only three enzyme activities and NADH as reducing equivalent. With reference to previously reported cell-free n-butanol reaction cascades, we have eliminated five enzyme activities and the requirement of CoA as cofactor. Our proof-of-concept demonstrates that n-butanol was synthesized at neutral pH and 50°C. This integrated reaction concept allowed GC detection of all reaction intermediates and n-butanol production of 148 mg L−1 (2 mM), which compares well with other cell-free n-butanol production processes. PMID:27800475

  16. Biochemical pathways generating post-mortem volatile compounds co-detected during forensic ethanol analyses.

    PubMed

    Boumba, Vassiliki A; Ziavrou, Kallirroe S; Vougiouklakis, Theodore

    2008-01-30

    In this contribution are presented the fermentations of the main substrates present in a decaying corpse, namely carbohydrates, amino acids, glycerol and fatty acids, generating the post-mortem volatile compounds that could be detected along with ethanol during the forensic ethanol analysis. The available literature (preferably reviews) on microbial metabolic pathways (enzymes, substrates, conditions) that are implicated in the formation of these volatiles has been reviewed. The microbial formation of the following volatiles is supported by the presented biochemical data: ethanol, acetaldehyde, acetone, 2-propanol, 1-propanol, 1-butanol, isobutanol, isoamyl alcohol, d-amyl alcohol, acetate, propionate, butyrate, isobutyrate and ethyl esters (mainly ethyl acetate). The extracted information was correlated with the existing forensic literature on the post-mortem detected volatiles. The significance of the microbial produced volatiles on the selection of an appropriate internal standard for the ethanol analysis has been considered. Finally, the possible contribution of the presence of volatiles in the interpretation of ethanol analysis results in post-mortem cases is discussed.

  17. Coculture Production of Butanol by Clostridium Bacteria

    NASA Technical Reports Server (NTRS)

    Bergstrom, S. L.; Foutch, G. L.

    1985-01-01

    Production of butanol by anaerobic fermentation of sugars enhanced by use of two Clostridium species, one of which feeds on metabolic product of other. Renewed interest in fermentation process for making butanol stimulated by potential use of butanol as surfactant in enhanced oil recovery. Butanol also used as fuel or as chemical feedstock and currently produced synthetically from petroleum.

  18. Acetone and isopropanol in ruminal fluid and feces of lactating dairy cows.

    PubMed

    Sato, Hiroshi; Shiogama, Yumiko

    2010-03-01

    Acetone and its metabolite isopropanol are produced by gut microbes as well as by the host's metabolism. To evaluate the production of acetone and isopropanol in alimentary tracts, a total of 80 pair-samples of feces and ruminal fluid were taken in lactating dairy cows that had been fed silage-containing diets. Acetone and isopropanol were analyzed, together with ethanol and volatile fatty acids (VFAs). Isopropanol was detected in 57 fecal and all the ruminal samples; however, the ruminal isopropanol and ethanol concentrations were distinctly lower than those in the feces. Acetone was detected in 13 fecal and 53 ruminal samples; however, there was no significant difference in acetone concentrations between the feces and the ruminal fluid. The group with higher fecal isopropanol concentration showed higher fecal proportions of acetate accompanied by low proportion of minor VFA, which consisted of isobutyrate and iso- and n-valerate. In the group with higher ruminal isopropanol concentration, ethanol concentration was higher; the ruminal VFA profiles showed only a negligible difference. Fecal and ruminal ethanol concentrations were not affected by feed ethanol. Thus, the colon showed an accelerated alcoholic fermentation compared with the rumen of dairy cows; however, acetone was present at higher frequency in the rumen than in the feces.

  19. Control of butanol formation in Clostridium acetobutylicum by transcriptional activation.

    PubMed

    Thormann, Kai; Feustel, Lothar; Lorenz, Karin; Nakotte, Stephan; Dürre, Peter

    2002-04-01

    The sol operon of Clostridium acetobutylicum is the essential transcription unit for formation of the solvents butanol and acetone. The recent proposal that transcriptional regulation of this operon is controlled by the repressor Orf5/SolR (R. V. Nair, E. M. Green, D. E. Watson, G. N. Bennett, and E. T. Papoutsakis, J. Bacteriol. 181:319-330, 1999) was found to be incorrect. Instead, regulation depends on activation, most probably by the multivalent transcription factor Spo0A. The operon is transcribed from a single promoter. A second signal identified in primer extension studies results from mRNA processing and can be observed only in the natural host, not in a heterologous host. The first structural gene in the operon (adhE, encoding a bifunctional butyraldehyde/butanol dehydrogenase) is translated into two different proteins, the mature AdhE enzyme and the separate butanol dehydrogenase domain. The promoter of the sol operon is preceded by three imperfect repeats and a putative Spo0A-binding motif, which partially overlaps with repeat 3 (R3). Reporter gene analysis performed with the lacZ gene of Thermoanaerobacterium thermosulfurigenes and targeted mutations of the regulatory region revealed that the putative Spo0A-binding motif, R3, and R1 are essential for control. The data obtained also indicate that an additional activator protein is involved.

  20. Fate of acetone in water

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.

    1982-01-01

    The physical, chemical, and biological processes that might affect the concentration of acetone in water were investigated in laboratory studies. Processes considered included volatilization, adsorption by sediments, photodecomposition, bacterial degradation, and absorption by algae and molds. It was concluded that volatilization and bacterial degradation were the dominant processes determining the fate of acetone in streams and rivers. ?? 1982.

  1. Recycling of acetone by distillation

    SciTech Connect

    Brennan, D.L.; Campbell, B.A.; Phelan, J.E.; Harper, M.

    1992-09-01

    The Resource Conservation Recovery Act (RCRA) identifies spent acetone solvent as a listed hazardous waste. At Fernald, acetone has been spent that has been contaminated with radionuclides and therefore is identified as a mixed hazardous waste. At the time of this publication there is no available approved method of recycling or disposal of radioactively contaminated spent acetone solvent. The Consent Decree with the Ohio EPA and the Consent Agreement with the United States EPA was agreed upon for the long-term compliant storage of hazardous waste materials. The purpose of this project was to demonstrate the feasibility for safely decontaminating spent acetone to background levels of radioactivity for reuse. It was postulated that through heat distillation, radionuclides could be isolated from the spent acetone.

  2. Glycerol supplementation of the growth medium enhances in situ detoxification of furfural by Clostridium beijerinckii during butanol fermentation.

    PubMed

    Ujor, Victor; Agu, Chidozie Victor; Gopalan, Venkat; Ezeji, Thaddeus Chukwuemeka

    2014-01-01

    Lignocellulose-derived microbial inhibitors such as furfural and 5-hydroxymethyl furfural adversely affect fermentation of lignocellulosic biomass hydrolysates to fuels and chemicals due to their toxicity on fermenting microbes. To harness the potential of lignocellulose as a cheap source of fermentable sugars, in situ detoxification of furfural and other lignocellulose-derived microbial inhibitors is essential. To enhance in situ detoxification and tolerance of furfural by Clostridium beijerinckii NCIMB 8052 during acetone-butanol-ethanol (ABE) fermentation, the effect of glycerol on NADH/NADPH generation and ABE production by furfural (4, 5, and 6 g/L)-challenged cultures was investigated in this study. In all instances, beneficial outcomes were observed. For example, the fermentation medium supplemented with glycerol and subjected to 5 g/L furfural elicited up to 1.8- and 3-fold increases, respectively, in NADH and NADPH levels in C. beijerinckii 8052 relative to the control culture. These critical changes are the likely underpinnings for the glycerol-mediated 2.3-fold increase in the rate of detoxification of 5 g/L furfural, substrate consumption, and ABE production compared to the unsupplemented medium. Collectively, these results demonstrate that increased intracellular NADH/NADPH in C. beijerinckii 8052 due to glycerol utilization engenders favorable effects on many aspects of cellular metabolism, including enhanced furfural reduction and increased ABE production.

  3. Shotgun proteomic monitoring of Clostridium acetobutylicum during stationary phase of butanol fermentation using xylose and comparison with the exponential phase

    SciTech Connect

    Sivagnanam, Kumaran; Raghavan, Vijaya G. S.; Shah, Manesh B; Hettich, Robert {Bob} L; Verberkmoes, Nathan C; Lefsrud, Mark G

    2012-01-01

    Economically viable production of solvents through acetone butanol ethanol (ABE) fermentation requires a detailed understanding of Clostridium acetobutylicum. This study focuses on the proteomic profiling of C. acetobutylicum ATCC 824 from the stationary phase of ABE fermentation using xylose and compares with the exponential growth by shotgun proteomics approach. Comparative proteomic analysis revealed 22.9% of the C. acetobutylicum genome and 18.6% was found to be common in both exponential and stationary phases. The proteomic profile of C. acetobutylicum changed during the ABE fermentation such that 17 proteins were significantly differentially expressed between the two phases. Specifically, the expression of five proteins namely, CAC2873, CAP0164, CAP0165, CAC3298, and CAC1742 involved in the solvent production pathway were found to be significantly lower in the stationary phase compared to the exponential growth. Similarly, the expression of fucose isomerase (CAC2610), xylulose kinase (CAC2612), and a putative uncharacterized protein (CAC2611) involved in the xylose utilization pathway were also significantly lower in the stationary phase. These findings provide an insight into the metabolic behavior of C. acetobutylicum between different phases of ABE fermentation using xylose.

  4. Enhanced butanol production by Clostridium acetobutylicum NCIMB 13357 grown on date fruit as carbon source in P2 medium.

    PubMed

    Khamaiseh, Emran I; Abdul Hamid, Aidil; Abdeshahian, Peyman; Wan Yusoff, Wan Mohtar; Kalil, Mohd Sahaid

    2014-01-01

    The production of biobutanol was studied by the cultivation of Clostridium acetobutylicum NCIMB 13557 in P2 medium including date fruit as the sole substrate. The effect of P2 medium and the effect of different concentrations of date fruit ranging from 10 to 100 g/L on biobutanol production were investigated. Anaerobic batch culture was carried out at 35 °C incubation temperature and pH 7.0 ± 0.2 for 72 h. Experimental results showed that the lowest yield of biobutanol and acetone-butanol-ethanol (ABE) was 0.32 and 0.35 gram per gram of carbohydrate consumed (g/g), respectively, when an initial date fruit concentration of 10 g/L was utilized. At this fruit date concentration a biobutanol production value of 1.56 g/L was obtained. On the other hand, the maximum yield of biobutanol (0.48 g/g) and ABE (0.63 g/g) was produced at 50 g/L date fruit concentration with a biobutanol production value as high as 11 g/L. However, when a higher initial date fruit concentration was used, biobutanol and ABE production decreased to reach the yield of 0.22 g/g and 0.35 g/g, respectively, where 100 g/L date fruit was used. Similar results also revealed that 10.03 g/L biobutanol was produced using 100 g/L date fruit.

  5. Dual substrate strategy to enhance butanol production using high cell inoculum and its efficient recovery by pervaporation.

    PubMed

    Yadav, Sweta; Rawat, Garima; Tripathi, Priyanka; Saxena, R K

    2014-01-01

    The present study deals with the development of an efficient ABE fermentation process using mixed substrate strategy for butanol production wherein no acetone was produced. For this, glucose was supplemented in the medium containing glycerol as main substrate which leads to a higher butanol production of 17.75 g/L in 72 h by Clostridium acetobutylicum KF158795. Moreover, the high cell inoculum also resulted in an increased ABE productivity of 0.46 g/L/h. Further, industrial scalability of the process was also successfully validated in a 300 L fermenter. Furthermore, potential of the Polymeric (PolyRMem) and Zeolite (ZeoMem) membranes for separation of butanol from fermentation broth was also studied by testing the pervaporation performance through which the butanol was successfully recovered.

  6. Heat transfer performance of a pulsating heat pipe charged with acetone-based mixtures

    NASA Astrophysics Data System (ADS)

    Wang, Wenqing; Cui, Xiaoyu; Zhu, Yue

    2016-12-01

    Pulsating heat pipes (PHPs) are used as high efficiency heat exchangers, and the selection of working fluids in PHPs has a great impact on the heat transfer performance. This study investigates the thermal resistance characteristics of the PHP charged with acetone-based binary mixtures, where deionized water, methanol and ethanol were added to and mixed with acetone, respectively. The volume mixing ratios were 2:1, 4:1 and 7:1, and the heating power ranged from 10 to 100 W with filling ratios of 45, 55, 62 and 70%. At a low filling ratio (45%), the zeotropic characteristics of the binary mixtures have an influence on the heat transfer performance of the PHP. Adding water, which has a substantially different boiling point compared with that of acetone, can significantly improve the anti-dry-out ability inside the PHP. At a medium filling ratio (55%), the heat transfer performance of the PHP is affected by both phase transition characteristics and physical properties of working fluids. At high heating power, the thermal resistance of the PHP with acetone-water mixture is between that with pure acetone and pure water, whereas the thermal resistance of the PHP with acetone-methanol and acetone-ethanol mixtures at mixing ratios of 2:1 and 4:1 is less than that with the corresponding pure fluids. At high filling ratios (62 and 70%), the heat transfer performance of the PHP is mainly determined by the properties of working fluids that affects the flow resistance. Thus, the PHP with acetone-methanol and acetone-ethanol mixtures that have a lower flow resistance shows better heat transfer performance than that with acetone-water mixture.

  7. Soy molasses as fermentation substrate for production of butanol using Clostridium beijerinckii BA101.

    PubMed

    Qureshi, N; Lolas, A; Blaschek, H P

    2001-05-01

    Spray-dried soy molasses (SDSM) contains the sugars dextrose, sucrose, fructose, pinitol, raffinose, verbascose, melibiose, and stachyose. Of the 746 g kg(-1) total sugars in SDSM, 434 g kg(-1) is fermentable using Clostridium beijerinckii BA101. SDSM was used to produce acetone, butanol, and ethanol (ABE) by C. beijerinckii BA101 in batch cultures. Using 80 g l(-1) SDSM, 10.7 g l(-1) ABE was produced in P2 medium. Higher concentrations of SDSM resulted in poor solvent production due to the presence of excessive salt and inhibitory components. C. beijerinckii BA101 in SDSM at 80 g l(-1) concentration produced 22.8 g l(-1) ABE when supplemented with 25.3 g l(-1) glucose. SDSM contains 57.4 g kg(-1) mineral ash and 2% tri-calcium phosphate. Tri-calcium phosphate up to 43.1 g l(-1) was not inhibitory and at a tri-calcium phosphate concentration of 28.8 g l(-1), the culture produced more solvents (30.1 g l(-1)) than the control experiment (23.8 g l(-1)). In contrast, sodium chloride was a strong inhibitor of C. beijerinckii BA101 cell growth. At a concentration of 10 g l(-1) sodium chloride, a maximum cell concentration of 0.6 g l(-1) was achieved compared to 1.7 g l(-1) in the control experiment. The effects of two salts on specific growth rate constant (mu) and specific rate of ABE production (nu) for C. beijerinckii BA101 were examined.

  8. Adaptation of lactic acid bacteria to butanol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butanol can be produced biologically through fermentation of various substrates by Gram-positive Clostridium species. However, to profitably produce butanol at industrial scales, new microbial biocatalysts with increased tolerance to butanol are needed. In this study we report the isolation and se...

  9. Utilization of pentoses from sugarcane biomass: techno-economics of biogas vs. butanol production.

    PubMed

    Mariano, Adriano Pinto; Dias, Marina O S; Junqueira, Tassia L; Cunha, Marcelo P; Bonomi, Antonio; Filho, Rubens Maciel

    2013-08-01

    This paper presents the techno-economics of greenfield projects of an integrated first and second-generation sugarcane biorefinery in which pentose sugars obtained from sugarcane biomass are used either for biogas (consumed internally in the power boiler) or n-butanol production via the ABE batch fermentation process. The complete sugarcane biorefinery was simulated using Aspen Plus®. Although the pentoses stream available in the sugarcane biorefinery gives room for a relatively small biobutanol plant (7.1-12 thousand tonnes per year), the introduction of butanol and acetone to the product portfolio of the biorefinery increased and diversified its revenues. Whereas the IRR of the investment on a biorefinery with biogas production is 11.3%, IRR varied between 13.1% and 15.2% in the butanol production option, depending on technology (regular or engineered microorganism with improved butanol yield and pentoses conversion) and target market (chemicals or automotive fuels). Additional discussions include the effects of energy-efficient technologies for butanol processing on the profitability of the biorefinery.

  10. Insights on Clusters Formation Mechanism by Time of Flight Mass Spectrometry. 2. The Case of Acetone-Water Clusters

    NASA Astrophysics Data System (ADS)

    Apicella, B.; Li, X.; Passaro, M.; Russo, C.

    2016-11-01

    This paper is the second of a series dealing with clusters formation mechanism. In part 1, water clusters with the addition of an electrophilic molecule such as ethanol were studied by Time Of Flight Mass Spectrometry (TOFMS). Mass distributions of molecular clusters of ethanol, water and ethanol-water mixed clusters, were obtained by means of two different ionization methods: Electron Ionization (EI) and picosecond laser Photo-Ionization (PI) at a wavelength of 355 nm. In part 2, the same experimental approach was employed to obtain mass spectra of clusters generated by acetone-water binary mixtures with a different composition. Strong dependence of the mass spectra of clusters with EI and PI on the acetone-water mixing ratio was observed. It was shown that the spectral pattern changes gradually and water-rich cluster signals become fainter while acetone-rich cluster signals become more intensive with increasing acetone concentrations from 0.3% to 40%. Owing to the hydrogen bond acceptor character of acetone, its self-association is discouraged with respect to ethanol. The autocorrelation function (AF) was used to analyze the variation of the water clusters composition with the increase of the acetone concentration in terms of fundamental periodicities. However, although acetone and ethanol present a very different hydrogen-bonding ability, similarly to ethanol-water system, in acetone-water system the formation of water-rich clusters and subsequent metastable fragmentation are the dominant process that determine the clusters distribution, irrespective of the ionization process, while the ionization process significantly affects the acetone-rich clusters distribution.

  11. Isolation of a solventogenic Clostridium sp. strain: fermentation of glycerol to n-butanol, analysis of the bcs operon region and its potential regulatory elements.

    PubMed

    Panitz, J C; Zverlov, V V; Pham, V T T; Stürzl, S; Schieder, D; Schwarz, W H

    2014-02-01

    A new solventogenic bacterium, strain GT6, was isolated from standing water sediment. 16S-rRNA gene analysis revealed that GT6 belongs to the heterogeneous Clostridium tetanomorphum group of bacteria exhibiting 99% sequence identity with C. tetanomorphum 4474(T). GT6 can utilize a wide range of carbohydrate substrates including glucose, fructose, maltose, xylose and glycerol to produce mainly n-butanol without any acetone. Additional products of GT6 metabolism were ethanol, butyric acid, acetic acid, and trace amounts of 1,3-propanediol. Medium and substrate composition, and culture conditions such as pH and temperature influenced product formation. The major fermentation product from glycerol was n-butanol with a final concentration of up to 11.5 g/L. 3% (v/v) glycerol lead to a total solvent concentration of 14 g/L within 72 h. Growth was not inhibited by glycerol concentrations as high as 15% (v/v). The solventogenesis genes crt, bcd, etfA/B and hbd composing the bcs (butyryl-CoA synthesis) operon of C. tetanomorphum GT6 were sequenced. They occur in a genomic arrangement identical to those in other solventogenic clostridia. Furthermore, the sequence of a potential regulator gene highly similar to that of the NADH-sensing Rex family of regulatory genes was found upstream of the bcs operon. Potential binding sites for Rex have been identified in the promoter region of the bcs operon of solvent producing clostridia as well as upstream of other genes involved in NADH oxidation. This indicates a fundamental role of Rex in the regulation of fermentation products in anaerobic, and especially in solventogenic bacteria.

  12. N-butanol and isobutanol as alternatives to gasoline: Comparison of port fuel injector characteristics

    NASA Astrophysics Data System (ADS)

    Fenkl, Michael; Pechout, Martin; Vojtisek, Michal

    2016-03-01

    The paper reports on an experimental investigation of the relationship between the pulse width of a gasoline engine port fuel injector and the quantity of the fuel injected when butanol is used as a fuel. Two isomers of butanol, n-butanol and isobutanol, are considered as potential candidates for renewable, locally produced fuels capable of serving as a drop-in replacement fuel for gasoline, as an alternative to ethanol which poses material compatibility and other drawbacks. While the injected quantity of fuel is typically a linear function of the time the injector coil is energized, the flow through the port fuel injector is complex, non ideal, and not necessarily laminar, and considering that butanol has much higher viscosity than gasoline, an experimental investigation was conducted. A production injector, coupled to a production fueling system, and driven by a pulse width generator was operated at various pulse lengths and frequencies, covering the range of engine rpm and loads on a car engine. The results suggest that at least at room temperature, the fueling rate remains to be a linear function of the pulse width for both n-butanol and isobutanol, and the volumes of fuel injected are comparable for gasoline and both butanol isomers.

  13. Identification of butanol tolerant genes in Lactobacillus mucosae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butanol, though in low concentrations, is produced biologically through fermentation of lignocellulosic biomass-derived substrates by Gram-positive Clostridium species. However, naturally available butanol fermenting microbes are sensitive to stress caused by increased production of butanol and the...

  14. Progress and perspectives on improving butanol tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fermentative production of butanol for use as a biofuel or chemical feedstock is regarded as a promising renewable technology that reduces greenhouse gas emissions and has the potential to become a substitute for non-sustainable chemical production route. However, butanol toxicity to the producing m...

  15. The preventive effect of N-butanol fraction of Nigella sativa on ethylene glycol-induced kidney calculi in rats

    PubMed Central

    Hadjzadeh, Mousa-Al-Reza; Rad, Abolfazl Khajavi; Rajaei, Ziba; Tehranipour, Maryam; Monavar, Nahid

    2011-01-01

    Background: The current study was carried out to determine whether the aqueous-ethanolic extract or the butanolic fraction of Nigella sativa (NS) seeds could prevent or reduce calculi aggregation in experimental calcium oxalate nephrolithiasis in Wistar rats. Materials and Methods: Male Wistar rats were randomly divided into 5 groups: group A received tap drinking water for 28 days. Groups B, C, D and E received 1% ethylene glycol for induction of calcium oxalate (CaOx) calculus formation for 28 days. Rats in groups C, D and E also received aqueous-ethanolic extract of NS, N-butanol fraction and N-butanol phase remnant of NS, respectively, in drinking water at a dose of 250 mg/kg for 28 days. Urine concentration of oxalate, citrate, and calcium on days 0, 14, and 28, and also serum concentration of magnesium and calcium on days 0 and 28, were measured. On day 29, kidneys were removed for histopathologic study and examined for counting the calcium oxalate deposits in 10 microscopic fields. Result: Treatment of rats with N-butanol fraction and N-butanol phase remnant of NS significantly reduced the number and size of kidney calcium oxalate deposits compared with ethylene glycol group. Urinary concentration of oxalate in all experimental groups increased compared with control group on days 14 and 28, whereas the urine citrate concentration was lower in all experimental groups compared with control group on days 14 and 28. Conclusion: N-butanol fraction and N-butanol phase remnant of NS showed a beneficial effect on calcium oxalate deposition in the rat kidney. Therefore, the butanolic fraction of NS may be suggested for prevention of calcium oxalate calculi in humans. PMID:22262938

  16. Metabolic engineering of Saccharomyces cerevisiae for the production of n-butanol

    SciTech Connect

    Steen, EricJ.; Chan, Rossana; Prasad, Nilu; Myers, Samuel; Petzold, Christopher; Redding, Alyssa; Ouellet, Mario; Keasling, JayD.

    2008-11-25

    BackgroundIncreasing energy costs and environmental concerns have motivated engineering microbes for the production of ?second generation? biofuels that have better properties than ethanol.Results& ConclusionsSaccharomyces cerevisiae was engineered with an n-butanol biosynthetic pathway, in which isozymes from a number of different organisms (S. cerevisiae, Escherichia coli, Clostridium beijerinckii, and Ralstonia eutropha) were substituted for the Clostridial enzymes and their effect on n-butanol production was compared. By choosing the appropriate isozymes, we were able to improve production of n-butanol ten-fold to 2.5 mg/L. The most productive strains harbored the C. beijerinckii 3-hydroxybutyryl-CoA dehydrogenase, which uses NADH as a co-factor, rather than the R. eutropha isozyme, which uses NADPH, and the acetoacetyl-CoA transferase from S. cerevisiae or E. coli rather than that from R. eutropha. Surprisingly, expression of the genes encoding the butyryl-CoA dehydrogenase from C. beijerinckii (bcd and etfAB) did not improve butanol production significantly as previously reported in E. coli. Using metabolite analysis, we were able to determine which steps in the n-butanol biosynthetic pathway were the most problematic and ripe for future improvement.

  17. Accurate High-Temperature Reaction Networks for Alternative Fuels: Butanol Isomers

    SciTech Connect

    Van Geem, K. M.; Pyl, S. P.; Marin, G. B.; Harper, M. R.; Green, W. H.

    2010-11-03

    Oxygenated hydrocarbons, particularly alcohol compounds, are being studied extensively as alternatives and additives to conventional fuels due to their propensity of decreasing soot formation and improving the octane number of gasoline. However, oxygenated fuels also increase the production of toxic byproducts, such as formaldehyde. To gain a better understanding of the oxygenated functional group’s influence on combustion properties—e.g., ignition delay at temperatures above the negative temperature coefficient regime, and the rate of benzene production, which is the common precursor to soot formation—a detailed pressure-dependent reaction network for n-butanol, sec-butanol, and tert-butanol consisting of 281 species and 3608 reactions is presented. The reaction network is validated against shock tube ignition delays and doped methane flame concentration profiles reported previously in the literature, in addition to newly acquired pyrolysis data. Good agreement between simulated and experimental data is achieved in all cases. Flux and sensitivity analyses for each set of experiments have been performed, and high-pressure-limit reaction rate coefficients for important pathways, e.g., the dehydration reactions of the butanol isomers, have been computed using statistical mechanics and quantum chemistry. The different alcohol decomposition pathways, i.e., the pathways from primary, secondary, and tertiary alcohols, are discussed. Furthermore, comparisons between ethanol and n-butanol, two primary alcohols, are presented, as they relate to ignition delay.

  18. An experimental and kinetic modeling study of combustion of isomers of butanol

    SciTech Connect

    Grana, Roberto; Frassoldati, Alessio; Faravelli, Tiziano; Ranzi, Eliseo; Niemann, Ulrich; Seiser, Reinhard; Cattolica, Robert; Seshadri, Kalyanasundaram

    2010-11-15

    A kinetic model is developed to describe combustion of isomers of butanol - n-butanol (n-C{sub 4}H{sub 9}OH), sec-butanol (sec-C{sub 4}H{sub 9}OH), iso-butanol (iso-C{sub 4}H{sub 9}OH), and tert-butanol (tert-C{sub 4}H{sub 9}OH). A hierarchical approach is employed here. This approach was previously found to be useful for developing detailed and semi-detailed mechanism of oxidation of various hydrocarbon fuels. This method starts from lower molecular weight compounds of a family of species and proceeds to higher molecular weight compounds. The pyrolysis and oxidation mechanisms of butanol isomers are similar to those for hydrocarbon fuels. Here, the development of the complete set of the primary propagation reactions for butanol isomers proceeds from the extension of the kinetic parameters for similar reactions already studied and recently revised for ethanol, n-propanol and iso-propanol. A detailed description leading to evaluation of rate constants for initiation reactions, metathesis reactions, decomposition reactions of alkoxy radicals, isomerization reactions, and four-center molecular dehydration reactions are given. Decomposition and oxidation of primary intermediate products are described using a previously developed semi-detailed kinetic model for hydrocarbon fuels. The kinetic mechanism is made up of more than 7000 reactions among 300 species. The model is validated by comparing predictions made using this kinetic model with previous and new experimental data on counterflow non-premixed flames of n-butanol and iso-butanol. The structures of these flames were measured by removing gas samples from the flame and analyzing them using a gas chromatograph. Temperature profiles were measured using coated thermocouples. The flame structures were measured under similar conditions for both fuels to elucidate the similarities and differences in combustion characteristics of the two isomers. The profiles measured include those of butanol, oxygen, carbon dioxide

  19. Enzymology of acetone-butanol-isopropanol formation. Progress report, June 16, 1990--June 15, 1993

    SciTech Connect

    Chen, Jiann-Shin

    1993-06-01

    During the current project period, alcohol dehydrogenases (ADH) and acetoacetyl-CoA-reacting enzymes of C. beijerinckii were purified to homogeneity. Structural and catalytic properties of the purged enzymes were determined. A range of conditions was used to investigate the activity and stability of each enzyme. This information will facilitate the selection of differential assays and handling conditions for the unequivocal determination of the activity of a specific enzyme in crude extracts. In genetic studies, crude extracts are often the most practical material for the monitoring of specific enzyme activities. A selective assay is especially important when the relative levels of interfering enzymes change during physiological or genetic manipulations. The results from our study of ADH and aldehyde dehydrogenase (ALDH) demonstrate the technical difficulties associated with the measurement of these enzyme activities in crude extracts. First of all, because the two enzymes catalyze sequential reactions, the NAD(P)H-linked activities of ADH and ALDH in crude extracts are easily over or underestimated or masked. Secondly, the presence of multiple ADHs with overlapping coenzyme specificities in the same cell makes it difficult to assign the measured activity to a specific isozyme. Lastly, these enzymes are especially oxygen-sensitive in crude extracts, which, necessitates the use of good anaerobic techniques. We have determined the N-terminal amino acid sequence (the first 30-45 residues) the primary/secondary ADH the ALDH, the 3-hydroxybutyryl-CoA dehydrogenase, and both subunits of the CoA-transferase. The amino acid sequences will allow us to design oligonucleotide probes for the cloning of their structural genes and then to study the organization and regulation of these genes. Using this approach, we have cloned and sequenced the ADH gene encoding the primary/secondary ADH.

  20. Systems analysis of the culture physiology in acetone-butanol fermentation

    SciTech Connect

    Yerushaimi, L.; Volesky, B.; Votruba, J.

    1986-09-01

    The pronounced differences in performance of a strain of Clostridium acetobutylicum ATCC 824 were analyzed by the method of systems analysis. The mechanism for cellular transport of substrate (glucose), solvents, and acids was studied and mathematically formulated. The systems analysis approach in the treatment of data from culture experiments pointed out the cell membrane malfunction indicated by its altered permeability and reflected in the altered number of active sugar transport sites. Experimental results obtained from the study of the cell uptake of 3-0-methyl glucose (0.7 mM) by the normal culture and the retarded culture confirmed the theoretical predictions regarding a slower transport in the retarded culture. The initial uptake rate and the accumulation coefficient of the sugar in the normal culture were 15.0 and 4.1 times higher, respectively, than those for the retarded culture. Adjustment of the culture pH resulted in further increases in these parameters by factors of 3.0 and 3.5, respectively.

  1. Simultaneous bioconversion of barley straw to butanol and product recovery: use of concentrated sugar solution and process integration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a result of increased gasoline prices, we focused on the production of butanol which contains more energy than ethanol on per gallon (or kg) basis from cellulosic agricultural biomass such as wheat straw using two different systems: i) separate hydrolysis, fermentation, and recovery (SHFR), and ...

  2. Pharmacokinetics and pharmacodynamics of ethanol, whiskey, and ethanol with n-propyl, n-butyl, and iso-amyl alcohols.

    PubMed

    Auty, R M; Branch, R A

    1977-08-01

    Plasma ethanol concentration, reaction time, and electroencephalogram (EEG) were recorded in 6 normal men after ingestion of ethanol along (Group 1), whiskey (Group 2), or a mixture of ethanol, n-propanol, n-butanol, and iso-amyl alcohol (Group 3). The peak plasma ethanol concentration and the total area under the plasma concentration:time curve of ethanol did not depend upon the type of drink given, but the half-life of the terminal exponential phase of ethanol elimination was longer in Group 3. In each study period reaction time increased, there was a relative increase in delta activity (2 to 3 Hz) and a fall in mean dominant frequency in EEG activity. The extent of increase in reaction time depended on the rate of increase in plasma ethanol concentration and correlated with the concentration of ethanol while the plasma concentration of ethanol was falling. Differences in the effects of ethanol between study periods were minimal.

  3. Biobutanol as Fuel for Direct Alcohol Fuel Cells-Investigation of Sn-Modified Pt Catalyst for Butanol Electro-oxidation.

    PubMed

    Puthiyapura, Vinod Kumar; Brett, Dan J L; Russell, Andrea E; Lin, Wen-Feng; Hardacre, Christopher

    2016-05-25

    Direct alcohol fuel cells (DAFCs) mostly use low molecular weight alcohols such as methanol and ethanol as fuels. However, short-chain alcohol molecules have a relative high membrane crossover rate in DAFCs and a low energy density. Long chain alcohols such as butanol have a higher energy density, as well as a lower membrane crossover rate compared to methanol and ethanol. Although a significant number of studies have been dedicated to low molecular weight alcohols in DAFCs, very few studies are available for longer chain alcohols such as butanol. A significant development in the production of biobutanol and its proposed application as an alternative fuel to gasoline in the past decade makes butanol an interesting candidate fuel for fuel cells. Different butanol isomers were compared in this study on various Pt and PtSn bimetallic catalysts for their electro-oxidation activities in acidic media. Clear distinctive behaviors were observed for each of the different butanol isomers using cyclic voltammetry (CV), indicating a difference in activity and the mechanism of oxidation. The voltammograms of both n-butanol and iso-butanol showed similar characteristic features, indicating a similar reaction mechanism, whereas 2-butanol showed completely different features; for example, it did not show any indication of poisoning. Ter-butanol was found to be inactive for oxidation on Pt. In situ FTIR and CV analysis showed that OHads was essential for the oxidation of primary butanol isomers which only forms at high potentials on Pt. In order to enhance the water oxidation and produce OHads at lower potentials, Pt was modified by the oxophilic metal Sn and the bimetallic PtSn was studied for the oxidation of butanol isomers. A significant enhancement in the oxidation of the 1° butanol isomers was observed on addition of Sn to the Pt, resulting in an oxidation peak at a potential ∼520 mV lower than that found on pure Pt. The higher activity of PtSn was attributed to the

  4. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acetone. 173.210 Section 173.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... established for acetone in spice oleoresins when present therein as a residue from the extraction of spice....

  5. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetone. 173.210 Section 173.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... established for acetone in spice oleoresins when present therein as a residue from the extraction of spice....

  6. Lignocellulosic butanol production from Napier grass using semi-simultaneous saccharification fermentation.

    PubMed

    He, Chi-Ruei; Kuo, Yu-Yuan; Li, Si-Yu

    2017-05-01

    Napier grass is a potential feedstock for biofuel production because of its strong adaptability and wide availability. Compositional analysis has been done on Napier grass which was collected from a local area of Taiwan. By comparing acid- and alkali-pretreatment, it was found that the alkali-pretreatment process is favorable for Napier grass. An overall glucose yield of 0.82g/g-glucosetotal can be obtained with the combination of alkali-pretreatment (2.5wt% NaOH, 8wt% sample loading, 121°C, and a reaction time of 40min) and enzymatic hydrolysis (40FPU/g-substrate). Semi-simultaneous saccharification fermentation (sSSF) was carried out, where enzymatic hydrolysis and ABE fermentation were operated in the same batch. It was found that after 24-h hydrolysis, followed by 96-h fermentation, the butanol and acetone concentrations reached 9.45 and 4.85g/L, respectively. The butanol yield reached 0.22g/g-sugarglucose+xylose. Finally, the efficiency of butanol production from Napier grass was calculated at 31%.

  7. Kinetics and products of the reaction of OH radicals with 3-methoxy-3-methyl-1-butanol.

    PubMed

    Aschmann, Sara M; Arey, Janet; Atkinson, Roger

    2011-08-15

    3-Methoxy-3-methyl-1-butanol [CH(3)OC(CH(3))(2)CH(2)CH(2)OH] is used as a solvent for paints, inks, and fragrances and as a raw material for the production of industrial detergents. A rate constant of (1.64 ± 0.18) × 10(-11) cm(3) molecule(-1) s(-1) for the reaction of 3-methoxy-3-methyl-1-butanol with OH radicals has been measured at 296 ± 2 K using a relative rate method, where the indicated error is the estimated overall uncertainty. Acetone, methyl acetate, glycolaldehyde, and 3-methoxy-3-methylbutanal were identified as products of the OH radical-initiated reaction, with molar formation yields of 3 ± 1%, 35 ± 9%, 13 ± 3%, and 33 ± 7%, respectively, at an average NO concentration of 1.3 × 10(14) molecules cm(-3). Using a 12-h average daytime OH radical concentration of 2 × 10(6) molecules cm(-3), the calculated lifetime of 3-methoxy-3-methyl-1-butanol with respect to reaction with OH radicals is 8.5 h. Potential reaction mechanisms are discussed.

  8. Alcohol Selectivity in a Synthetic Thermophilic n-Butanol Pathway Is Driven by Biocatalytic and Thermostability Characteristics of Constituent Enzymes

    PubMed Central

    Loder, Andrew J.; Zeldes, Benjamin M.; Garrison, G. Dale; Lipscomb, Gina L.; Adams, Michael W. W.

    2015-01-01

    n-Butanol is generated as a natural product of metabolism by several microorganisms, but almost all grow at mesophilic temperatures. A synthetic pathway for n-butanol production from acetyl coenzyme A (acetyl-CoA) that functioned at 70°C was assembled in vitro from enzymes recruited from thermophilic bacteria to inform efforts for engineering butanol production into thermophilic hosts. Recombinant versions of eight thermophilic enzymes (β-ketothiolase [Thl], 3-hydroxybutyryl-CoA dehydrogenase [Hbd], and 3-hydroxybutyryl-CoA dehydratase [Crt] from Caldanaerobacter subterraneus subsp. tengcongensis; trans-2-enoyl-CoA reductase [Ter] from Spirochaeta thermophila; bifunctional acetaldehyde dehydrogenase/alcohol dehydrogenase [AdhE] from Clostridium thermocellum; and AdhE, aldehyde dehydrogenase [Bad], and butanol dehydrogenase [Bdh] from Thermoanaerobacter sp. strain X514) were utilized to examine three possible pathways for n-butanol. These pathways differed in the two steps required to convert butyryl-CoA to n-butanol: Thl-Hbd-Crt-Ter-AdhE (C. thermocellum), Thl-Hbd-Crt-Ter-AdhE (Thermoanaerobacter X514), and Thl-Hbd-Crt-Ter-Bad-Bdh. n-Butanol was produced at 70°C, but with different amounts of ethanol as a coproduct, because of the broad substrate specificities of AdhE, Bad, and Bdh. A reaction kinetics model, validated via comparison to in vitro experiments, was used to determine relative enzyme ratios needed to maximize n-butanol production. By using large relative amounts of Thl and Hbd and small amounts of Bad and Bdh, >70% conversion to n-butanol was observed in vitro, but with a 60% decrease in the predicted pathway flux. With more-selective hypothetical versions of Bad and Bdh, >70% conversion to n-butanol is predicted, with a 19% increase in pathway flux. Thus, more-selective thermophilic versions of Bad, Bdh, and AdhE are needed to fully exploit biocatalytic n-butanol production at elevated temperatures. PMID:26253677

  9. Towards improved butanol production through targeted genetic modification of Clostridium pasteurianum.

    PubMed

    Schwarz, Katrin M; Grosse-Honebrink, Alexander; Derecka, Kamila; Rotta, Carlo; Zhang, Ying; Minton, Nigel P

    2017-03-01

    Declining fossil fuel reserves, coupled with environmental concerns over their continued extraction and exploitation have led to strenuous efforts to identify renewable routes to energy and fuels. One attractive option is to convert glycerol, a by-product of the biodiesel industry, into n-butanol, an industrially important chemical and potential liquid transportation fuel, using Clostridium pasteurianum. Under certain growth conditions this Clostridium species has been shown to predominantly produce n-butanol, together with ethanol and 1,3-propanediol, when grown on glycerol. Further increases in the yields of n-butanol produced by C. pasteurianum could be accomplished through rational metabolic engineering of the strain. Accordingly, in the current report we have developed and exemplified a robust tool kit for the metabolic engineering of C. pasteurianum and used the system to make the first reported in-frame deletion mutants of pivotal genes involved in solvent production, namely hydA (hydrogenase), rex (Redox response regulator) and dhaBCE (glycerol dehydratase). We were, for the first time in C. pasteurianum, able to eliminate 1,3-propanediol synthesis and demonstrate its production was essential for growth on glycerol as a carbon source. Inactivation of both rex and hydA resulted in increased n-butanol titres, representing the first steps towards improving the utilisation of C. pasteurianum as a chassis for the industrial production of this important chemical.

  10. Simultaneous saccharification and fermentation of lignocellulosic residues pretreated with phosphoric acid-acetone for bioethanol production.

    PubMed

    Li, Hui; Kim, Nag-Jong; Jiang, Min; Kang, Jong Won; Chang, Ho Nam

    2009-07-01

    Bermudagrass, reed and rapeseed were pretreated with phosphoric acid-acetone and used for ethanol production by means of simultaneous saccharification and fermentation (SSF) with a batch and fed-batch mode. When the batch SSF experiments were conducted in a 3% low effective cellulose, about 16 g/L of ethanol were obtained after 96 h of fermentation. When batch SSF experiments were conducted with a higher cellulose content (10% effective cellulose for reed and bermudagrass and 5% for rapeseed), higher ethanol concentrations and yields (of more than 93%) were obtained. The fed-batch SSF strategy was adopted to increase the ethanol concentration further. When a higher water-insoluble solid (up to 36%) was applied, the ethanol concentration reached 56 g/L of an inhibitory concentration of the yeast strain used in this study at 38 degrees C. The results show that the pretreated materials can be used as good feedstocks for bioethanol production, and that the phosphoric acid-acetone pretreatment can effectively yield a higher ethanol concentration.

  11. Metabolic process engineering of Clostridium tyrobutyricum Δack-adhE2 for enhanced n-butanol production from glucose: effects of methyl viologen on NADH availability, flux distribution, and fermentation kinetics.

    PubMed

    Du, Yinming; Jiang, Wenyan; Yu, Mingrui; Tang, I-Ching; Yang, Shang-Tian

    2015-04-01

    Butanol biosynthesis through aldehyde/alcohol dehydrogenase (adhE2) is usually limited by NADH availability, resulting in low butanol titer, yield, and productivity. To alleviate this limitation and improve n-butanol production by Clostridium tyrobutyricum Δack-adhE2 overexpressing adhE2, the NADH availability was increased by using methyl viologen (MV) as an artificial electron carrier to divert electrons from ferredoxin normally used for H2 production. In the batch fermentation with the addition of 500 μM MV, H2 , acetate, and butyrate production was reduced by more than 80-90%, while butanol production increased more than 40% to 14.5 g/L. Metabolic flux analysis revealed that butanol production increased in the fermentation with MV because of increased NADH availability as a result of reduced H2 production. Furthermore, continuous butanol production of ∼55 g/L with a high yield of ∼0.33 g/g glucose and extremely low ethanol, acetate, and butyrate production was obtained in fed-batch fermentation with gas stripping for in situ butanol recovery. This study demonstrated a stable and reliable process for high-yield and high-titer n-butanol production by metabolically engineered C. tyrobutyricum by applying MV as an electron carrier to increase butanol biosynthesis.

  12. Flame Propagation of Butanol Isomers/Air Mixtures

    SciTech Connect

    Veloo, Peter S.; Egolfopoulos, Fokion N.

    2011-01-01

    An experimental and computational study was conducted on the propagation of flames of saturated butanol isomers. The experiments were performed in the counterflow configuration under atmospheric pressure, unburned mixture temperature of 343 K, and for a wide range of equivalence ratios. The experiments were simulated using a recent kinetic model for the four isomers of butanol. Results indicate that n-butanol/air flames propagate somewhat faster than both sec-butanol/air and iso-butanol/air flames, and that tert-butanol/air flames propagate notably slower compared to the other three isomers. Reaction path analysis of tert-butanol/air flames revealed that iso-butene is a major intermediate, which subsequently reacts to form the resonantly stable iso-butenyl radical retarding thus the overall reactivity of tert-butanol/air flames relatively to the other three isomers. Through sensitivity analysis, it was determined that the mass burning rates of sec-butanol/air and iso-butanol/air flames are sensitive largely to hydrogen, carbon monoxide, and C{sub 1}–C{sub 2} hydrocarbon kinetics and not to fuel-specific reactions similarly to n-butanol/air flames. However, for tert-butanol/air flames notable sensitivity to fuel-specific reactions exists. While the numerical results predicted closely the experimental data for n-butanol/air and sec-butanol/air flames, they overpredicted and underpredicted the laminar flame speeds for iso-butanol/air and tert-butanol/air flames respectively. It was demonstrated further that the underprediction of the laminar flame speeds of tert-butanol/air flames by the model was most likely due to deficiencies of the C{sub 4}-alkene kinetics.

  13. Two-stage bile preparation with acetone for recovery of fluorescent aromatic compounds (FACs).

    PubMed

    Karami, Ali; Syed, Mohd A; Christianus, Annie; Willett, Kristine L; Mazzeo, Jeffrey R; Courtenay, Simon C

    2012-07-15

    In this study we sought to optimize recovery of fluorescent aromatic compounds (FACs) from the bile of African catfish (Clarias gariepinus) injected with 10mg/kg benzo[a]pyrene (BaP). Fractions of pooled bile were hydrolyzed, combined with ten volumes of methanol, ethanol, acetonitrile, or acetone, centrifuged and supernatants were analyzed by high-performance liquid chromatography with fluorescent detection (HPLC/FL). As well, to test whether FACs were being lost in solids from the centrifugation, pellets were resuspended, hydrolyzed and mixed with six volumes of the organic solvent that produced best FAC recovery from the supernatant, and subjected to HPLC/FL. Highest FAC concentrations were obtained with 2000μl and 1250μl acetone for supernatants and resuspended pellets respectively. FACs concentrations were negatively correlated with biliary protein content but were unaffected by addition of bovine serum albumin (BSA) followed by no incubation indicating that the presence of proteins in the biliary mixture does not simply interfere with detection of FACs. In another experiment, efficiency of acetone addition was compared to two different liquid-liquid extractions (L-LEs). Acetone additions provided significantly higher biliary FACs than the L-LE methods. The new two-stage bile preparation with acetone is an efficient, inexpensive and easily performed method.

  14. Enhanced Butanol Production Through Adding Organic Acids and Neutral Red by Newly Isolated Butanol-Tolerant Bacteria.

    PubMed

    Jiang, Cheng; Cao, Guangli; Wang, Zhenyu; Li, Ying; Song, Jinzhu; Cong, Hua; Zhang, Junzheng; Yang, Qian

    2016-12-01

    As alternative microorganisms for butanol production with high butanol tolerant and productivity are in high demand, one excellent butanol-tolerant bacterium, S10, was isolated and identified as Clostridium acetobutylicum S10. In order to enhance the performance of butanol production, organic acids and neutral red were added during butanol fermentation. Synergistic effects were exhibited in the combinations of organic acids and neutral red to promote butanol production. Consequently, the optimal concentrations of combined acetate, butyrate, and neutral red were determined at sodium acetate 1.61 g/L, sodium butyrate 1.88 g/L, and neutral red 0.79 g/L, respectively, with the butanol yield of 6.09 g/L which was 20.89 % higher than that in control. These results indicated that combination of adding organic acid and neutral red is a potential effective measure to improve butanol production.

  15. 40 CFR 721.10592 - 1-Butanol, 4-amino-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 1-Butanol, 4-amino-. 721.10592 Section... Substances § 721.10592 1-Butanol, 4-amino-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-butanol, 4-amino- (PMN P-11-130; CAS No....

  16. 40 CFR 721.10592 - 1-Butanol, 4-amino-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 1-Butanol, 4-amino-. 721.10592 Section... Substances § 721.10592 1-Butanol, 4-amino-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-butanol, 4-amino- (PMN P-11-130; CAS No....

  17. Critical roles of Rho-associated kinase in membrane blebbing and mitochondrial pathway of apoptosis caused by 1-butanol.

    PubMed

    Noritake, Kanako; Aki, Toshihiko; Funakoshi, Takeshi; Unuma, Kana; Nara, Akina; Kato, Chizuru; Uemura, Koichi

    2012-09-01

    Alcohols are widely used as industrial solvents and chemical intermediates but can cause serious damage to human health. Nevertheless, few studies have addressed the molecular mechanisms underlying the cytotoxicity of industrial alcohols, with the notable exception of ethanol. The goal of our current study is to elucidate the molecular mechanism of cytotoxicity caused by primary alcohols containing longer carbon chains than ethanol. We find that 1-butanol induces morphological changes in H9c2 cardiomyoblastoma including nuclear condensation and membrane blebbing, both of which are features of apoptotic response. Moreover, a decrease in the mitochondrial membrane potential, the cytosolic release of cytochrome c, and the activation of caspase 9 and 3 was observed, thus revealing the activation of the mitochondrial apoptotic pathway by 1-butanol. The addition of Y-27632, a specific inhibitor of Rho-associated kinase (ROCK), suppressed the membrane blebbing and mitochondrial apoptotic pathway. In comparison z-VAD-fmk, a pan-caspase inhibitor, did not inhibit membrane blebbing but did prevent cell death following exposure to 1-butanol. These results indicate that mitochondrial pathway of apoptosis and membrane blebbing are parallel phenomena that occur downstream of ROCK. This kinase thus plays an essential role in 1-butanol cytotoxicity and subsequent cell death in H9c2 cells.

  18. Critical Heat Flux of Butanol Aqueous Solution

    NASA Astrophysics Data System (ADS)

    Nishiguchi, Shotaro; Shoji, Masahiro

    It is known that the addition of small amount of alcohol such as butanol to water enhances the CHF. Such aqueous solution is actively applied to heat transfer devices such as heat pipes and microchannel cooling systems, however, the fundamental characters of boiling have not been fully understood. In the present research, the experiment of boiling heat transfer is performed on a heated wire by employing butanol aqueous solution as a typical test solution and by changing concentration 1-butanol and subcooling in a wide range. Bubbling aspects were observed using high-speed video camera. It is found from the experiment that CHF is 2 to 3 times higher than that of pure water and generating bubbles are tiny even at the saturated condition. The dependence of CHF on subcooling is found to be curious showing that CHF decreases first, takes a minimum, and then increases with increasing subcooling. These results suggest that the butanol aqueous solution is a promising liquid for the application of boiling to a small-scaled cooling device.

  19. Effects of butanol on Clostridium acetobutylicum.

    PubMed Central

    Bowles, L K; Ellefson, W L

    1985-01-01

    The internal pH of Clostridium acetobutylicum was determined at various stages during the growth of the organism. Even in the presence of significant quantities of acetic, butyric, and lactic acids, an internal pH of 6.2 was maintained. Experiments using N,N'-dicyclohexylcarbodiimide indicated that a functioning H+-ATPase is necessary for internal pH control. Butanol, one of the end products of the fermentation, had numerous harmful effects on C. acetobutylicum. At a concentration high enough to inhibit growth, butanol destroyed the ability of the cell to maintain internal pH, lowered the intracellular level of ATP, and inhibited glucose uptake. Experiments done at two different external pH values suggested that the butanol-mediated decrease in ATP concentration was independent of the drop in internal pH. Glucose uptake was not affected by arsenate, suggesting that uptake was not ATP dependent. The effects of butanol on C. acetobutylicum are complex, inhibiting several interrelated membrane processes. PMID:2868690

  20. Recovery of butanol by counter-current carbon dioxide fractionation with its potential application to butanol fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A counter-current CO2 fractionation method was studied as a means to recover butanol (also known as 1-butanol or n-butanol) and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating parameters, such as solvent-to-feed ratio,...

  1. Production of 2-methyl-1-butanol and 3-methyl-1-butanol in engineered Corynebacterium glutamicum.

    PubMed

    Vogt, Michael; Brüsseler, Christian; Ooyen, Jan van; Bott, Michael; Marienhagen, Jan

    2016-11-01

    The pentanol isomers 2-methyl-1-butanol and 3-methyl-1-butanol represent commercially interesting alcohols due to their potential application as biofuels. For a sustainable microbial production of these compounds, Corynebacterium glutamicum was engineered for producing 2-methyl-1-butanol and 3-methyl-1-butanol via the Ehrlich pathway from 2-keto-3-methylvalerate and 2-ketoisocaproate, respectively. In addition to an already available 2-ketoisocaproate producer, a 2-keto-3-methylvalerate accumulating C. glutamicum strain was also constructed. For this purpose, we reduced the activity of the branched-chain amino acid transaminase in an available C. glutamicuml-isoleucine producer (K2P55) via a start codon exchange in the ilvE gene enabling accumulation of up to 3.67g/l 2-keto-3-methylvalerate. Subsequently, nine strains expressing different gene combinations for three 2-keto acid decarboxylases and three alcohol dehydrogenases were constructed and characterized. The best strains accumulated 0.37g/l 2-methyl-1-butanol and 2.76g/l 3-methyl-1-butanol in defined medium within 48h under oxygen deprivation conditions, making these strains ideal candidates for additional strain and process optimization.

  2. Anti-inflammatory effect of ethanol and other alcohols on rat paw edema and pleurisy.

    PubMed

    Strubelt, O; Zetler, G

    1980-06-01

    The rat paw edema due to carrageenan, yeast, and dextran was dose-dependently antagonized by oral administration of ethanol. Carrageenan-induced paw edema was also inhibited by methanol, 1-propanol, and 1-butanol. The rat carrageenan pleurisy was reduced by oral pretreatment with methanol, ethanol, 1-propanol, 1-butanol, and dimethyl sulfoxide. Central depression, altered adrenal functions, increased osmolality, and hypothermia were no important factors for these actions of solvents. It is concluded that the inhibitory effect of ethanol on inflammatory responses increases the susceptibility of alcoholics to infection.

  3. Metabolic engineering of Thermoanaerobacterium saccharolyticum for n-butanol production

    SciTech Connect

    Bhandiwad, Ashwini; Shaw, A Joe; Guss, Adam M; Guseva, Anna; Lynd, Lee R

    2014-01-01

    The thermophilic anaerobe Thermoanaerobacterium saccharolyticum JW/SL-YS485 was investigated as a host for n-butanol production. A systematic approach was taken to demonstrate functionality of heterologous components of the clostridial n-butanol pathway via gene expression and enzymatic activity assays in this organism. Subsequently, integration of the entire pathway in the wild-type strain resulted in n-butanol production of 0.85 g/L from 10 g/L xylose, corresponding to 21% of the theoretical maximum yield. We were unable to integrate the n-butanol pathway in strains lacking the ability to produce acetate, despite the theoretical overall redox neutrality of n-butanol formation. However, integration of the n-butanol pathway in lactate deficient strains resulted in n-butanol production of 1.05 g/L from 10 g/L xylose, corresponding to 26% of the theoretical maximum.

  4. Photochemistry of Acetone in Simulated Atmosphere

    NASA Astrophysics Data System (ADS)

    Chakraborty, T.; Ghosh, A. K.; Chattopadhyay, A.

    2013-06-01

    Acetone has been identified to be one of the dominant non-methane organic species present in our atmosphere with an annual budget of ˜40-60; Tg; (10^{12} ;g). It has been proposed that the major fraction of atmospheric acetone (˜65%) is removed via photodissociation channel. Numerous laboratory investigations were devoted in the past to understand how the reactions are evolved in presence of oxygen and water vapour. Our recent study, wherein the photo products are probed using a tandem methodology of quadrupole mass spectrometry and gas-phase infrared spectroscopy reveals that a significant fraction of acetone is converted to formic acid in presence of oxygen when exposed to ultraviolet light of wavelengths available in troposphere. The measurement has been repeated with other linear and cyclic ketones and some of their deuterated analogues. The details of our findings will be presented in the talk.

  5. Acetone transport in poly(ethylene terephthalate)

    NASA Astrophysics Data System (ADS)

    Ouyang, Hao; Chen, Che-Chen

    1997-05-01

    Organic solvents like acetone can penetrate into poly(ethylene terephthalate) (PET). The model of case I (Fickian) and case II (swelling) is employed to study the phenomenon of mass transport. This model is successful in explaining the behavior of mass transport in an amorphous polymer, for example, poly(methyl methacrylate) (PMMA). The characteristic parameters, diffusivity D and velocity v, can be obtained from the analysis of experimental data. The mass transport in PET is different from that in PMMA. It is accompanied by a large-scale structural rearrangement, which leads to induced crystallization of the original amorphous state. This is the so-called "solvent-induced crystallization." Acetone-induced crystallization was confirmed by x-ray diffraction. The differential scanning calorimetry thermograms of acetone-treated PET show that the crystallization peak disappears and the glass transition temperature decreases.

  6. Preliminary toxicological study of ferric acetyl acetonate

    SciTech Connect

    London, J.E.; Smith, D.M.

    1983-01-01

    The calculated acute oral LD/sub 50//sup 30/ (lethal does for 50% of the animals occuring with 30 days after compound administration) values for ferric acetyl acetonate were 584 mg/kg in mice and 995 mg/kg in rats. According to classical guidelines, this compound would be considered slightly toxic in both species. Skin application studies in the rabbit demonstrated the compound to be irritating. The eye irritation study disclosed the compound to be a severe irritant causing permanent damage to the cornea (inflammation and scarring resulting in blindness). The sensitization study in the guinea pig did not show ferric acetyl acetonate to be deleterious in this regard.

  7. Bacterial degradation of acetone in an outdoor model stream

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Tai, D.Y.

    1993-01-01

    Diurnal variations of the acetone concentration in an outdoor model stream were measured with and without a nitrate supplement to determine if the nitrate supplement would stimulate bacterial degradation of the acetone. Acetone loss coefficients were computed from the diurnal data using a fitting procedure based on a Lagrangian particle model. The coefficients indicated that bacterial degradation of the acetone was occurring in the downstream part of the stream during the nitrate addition. However, the acetone concentrations stabilized at values considerably above the limit of detection for acetone determination, in contrast to laboratory respirometer studies where the acetone concentration decreased rapidly to less than the detection limit, once bacterial acclimation to the acetone had occurred. One possible explanation for the difference in behavior was the limited 6-hour residence time of the acetone in the model stream.

  8. Butanol and hexanol production in Clostridium carboxidivorans syngas fermentation: Medium development and culture techniques.

    PubMed

    Phillips, John R; Atiyeh, Hasan K; Tanner, Ralph S; Torres, Juan R; Saxena, Jyotisna; Wilkins, Mark R; Huhnke, Raymond L

    2015-08-01

    Clostridium carboxidivorans was grown on model syngas (CO:H2:CO2 [70:20:10]) in a defined nutrient medium with concentrations of nitrogen, phosphate and trace metals formulated to enhance production of higher alcohols. C. carboxidivorans was successfully grown in a limited defined medium (no yeast extract, no MES buffer and minimal complex chemical inputs) using an improved fermentation protocol. Low partial pressure of CO in the headspace, coupled with restricted mass transfer for CO and H2, was required for successful fermentation. In the absence of substrate inhibition (particularly from CO), growth limitation increased production of alcohols, especially butanol and hexanol. Concentrations of butanol (over 1.0g/L), hexanol (up to 1.0g/L) and ethanol (over 3.0g/L) were achieved in bottle fermentations. Minimal medium and controlled supply of CO and H2 should be used in characterizing candidate butanol and hexanol producing strains to select for commercial potential.

  9. [Performance optimization of property-improved biodiesel manufacturing process coupled with butanol extractive fermentation].

    PubMed

    Zhang, Longyun; Yang, Ying; Shi, Zhongping

    2008-11-01

    The products concentrations in traditional acetone-butanol (AB) fermentation are too low that large amount of energy has to be consumed in the distillation and product recovery process. Aiming at direct utilization of the fermentation products, in this study, optimization of property-improved biodiesel manufacturing process coupled with AB extractive fermentation was conducted, under the condition of using the biodiesel originated from waste cooking oil as the extractant and high concentrated corn flour medium. The effect of biodiesel/broth volume ratio, waste supernatant recycle ratio, and electronic carrier addition on the major process performance index was carefully investigated. Under the optimized condition, the biodiesel quality was improved with the cetane value increased from 51.4 to 54.4; "actual butanol yield" reached to a level of 18%, and waste supernatant recycle ratio exceeded 50%. In this way, elimination of energy-consuming product recovery process and realization of "energy-saving & waste minimization" industrial production target advocated by the state government, could be potentially expected.

  10. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acetone. 173.210 Section 173.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Solvents, Lubricants, Release Agents and...

  11. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.802... proportions of higher polymers, manufactured by reaction of hydrogen peroxide and acetone. (b) The additive... additive container and any intermediate premix thereof shall bear, in addition to the other...

  12. Acetone excretion into urine of workers exposed to acetone in acetate fiber plants.

    PubMed

    Satoh, T; Omae, K; Takebayashi, T; Nakashima, H; Higashi, T; Sakurai, H

    1995-01-01

    To develop a proper protocol for biological exposure monitoring of acetone, we evaluated whether exposure to acetone on the previous day affects the biological monitoring value at the end of a work day. One hundred and ten male workers exposed to acetone in three acetate fiber manufacturing plants were monitored using a liquid passive sampler on two consecutive working days after 2 days without exposure. Urine samples were collected at the start of the workshift and the end of the shift on both days for each subject. For ten exposed workers urine samples were collected approximately every 2 h during and after the first working day until the following morning. Acetone concentrations in urine (Cu) at the start of the first working day were 1.3 +/- 2.4 (range: ND-14.1) mg/l in nonexposed workers and 2.4 +/- 5.6 (range: ND-40.3) mg/l in exposed workers. The urinary acetone concentration at the beginning of the second working day indicated that urinary levels of acetone do not decline to background level by the following morning when exposure concentration exceeds 300 ppm. However, linear regression analysis demonstrated that the relationship between environmental exposure level and urine level was similar on the 1st day and the 2nd day. Thus, although urine acetone levels did not return completely to baseline after high exposures, under the present exposure levels the exposure on the previous day did not significantly affect urinary acetone at the end of the workshift of the next day.

  13. Ethanol poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002644.htm Ethanol poisoning To use the sharing features on this page, please enable JavaScript. Ethanol poisoning is caused by drinking too much alcohol. ...

  14. Ethanol Basics

    SciTech Connect

    2015-01-30

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  15. Interaction between amylose and 1-butanol during 1-butanol-hydrochloric acid hydrolysis of normal rice starch.

    PubMed

    Hu, Xiuting; Wei, Benxi; Zhang, Bao; Li, Hongyan; Xu, Xueming; Jin, Zhengyu; Tian, Yaoqi

    2013-10-01

    The aim of this study was to examine the interaction between amylose and 1-butanol during the 1-butanol-hydrochloric acid (1-butanol-HCl) hydrolysis of normal rice starch. The interaction model between amylose and 1-butanol was proposed using gas chromatography-mass spectrometry (GC-MS), (13)C cross polarization and magic angle spinning NMR analysis ((13)C CP/MAS NMR), differential scanning calorimetry (DSC), and thermalgravimetric analysis (TGA). GC-MS data showed that another form of 1-butanol existed in 1-butanol-HCl-hydrolyzed normal rice starch, except in the form of free molecules absorbed on the starch granules. The signal of 1-butanol-HCl-hydrolyzed starch at 100.1 ppm appeared in the (13)C CP/MAS NMR spectrum, indicating that the amylose-1-butanol complex was formed. DSC and TGA data also demonstrated the formation of the complex, which significantly affected the thermal properties of normal rice starch. These findings revealed that less dextrin with low molecular weight formed might be attributed to resistance of this complex to acid during 1-butanol-HCl hydrolysis.

  16. Oxidation of 1-butanol and a mixture of n-heptane/1-butanol in a motored engine

    SciTech Connect

    Zhang, Yu.; Boehman, Andre L.

    2010-10-15

    The oxidation of neat 1-butanol and a mixture of n-heptane and 1-butanol was studied in a modified CFR engine at an equivalence ratio of 0.25 and an intake temperature of 120 C. The engine compression ratio was gradually increased from the lowest point to the point where significant high temperature heat release was observed. Heat release analyses showed that no noticeable low temperature heat release behavior was observed from the oxidation of neat 1-butanol while the n-heptane/1-butanol mixture exhibited pronounced cool flame behavior. Species concentration profiles were obtained via GC-MS and GC-FID/TCD. Quantitative analyses of the reaction products from the oxidation of neat 1-butanol indicate that 1-butanol is consumed mainly through H-atom abstraction. Among the H-atom abstraction reactions, it is observed that the H-atom abstraction from the {alpha}-carbon of 1-butanol is particularly favored. The investigation on the oxidation of the mixture of n-heptane/1-butanol showed that the oxidation of 1-butanol is facilitated at low temperatures through the radical pool generated from the oxidation of n-heptane. (author)

  17. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  18. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  19. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  20. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  1. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  2. Acetone potentiation of acute acetonitrile toxicity in rats

    SciTech Connect

    Freeman, J.J.; Hayes, E.P.

    1985-01-01

    The purpose of these studies was to investigate the nature and mechanism of a toxicologic interaction between acetonitrile and acetone. Results of oral doe-response studies utilizing 1:1 (w/w) mixture of acetonitrile and acetone, or varying doses of acetonitrile administered together with a constant dose of acetone, indicated that acetone potentiated acute acetonitrile toxicity three- to fourfold in rats. The onset of severe toxicity (manifested by tremors and convulsions) was delayed in the groups dosed with both solvents compared to the groups that received acetonitrile or acetone alone. Blood cyanide (a metabolite of acetonitrile) and serum acetonitrile and acetone concentrations were measured after oral administration of 25% aqueous solutions of acetonitrile, acetone, or acetonitrile plus acetone. Concentrations of cyanide in the blood of rats given acetonitrile plus acetone remained near baseline, in contrast to the high concentrations found in rats dosed with acetonitrile alone. At 34-36 h, high blood cyanide concentrations were found in rats dosed with both of the solvents. This delayed onset of elevation of blood cyanide coincided with the occurrence of clinical signs and with the disappearance of serum acetone. In further pharmacokinetic studies, blood cyanide concentrations were measured after similar dosage regimens of acetone and acetonitrile. Peak cyanide concentrations were found to be significantly greater in rats dosed with both solvents than in rats given only acetonitrile. Administration of either sodium thiosulfate or a second dose of acetone prevented the toxicity associated with exposure to both solvents.

  3. Butanol biorefineries: Use of novel technologies to produce biofuel butanol from sweet sorghum bagasse (SSB)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to produce butanol biofuel at a competitive price, agricultural residues such as SSB should be used. This feedstock was studied as a substitute to corn to lower feedstock costs and broaden beyond a food crop. In addition, cutting edge science & technology was applied. In these studies we us...

  4. Selective n-butanol production by Clostridium sp. MTButOH1365 during continuous synthesis gas fermentation due to expression of synthetic thiolase, 3-hydroxy butyryl-CoA dehydrogenase, crotonase, butyryl-CoA dehydrogenase, butyraldehyde dehydrogenase, and NAD-dependent butanol dehydrogenase.

    PubMed

    Berzin, Vel; Tyurin, Michael; Kiriukhin, Michael

    2013-02-01

    Acetogen Clostridum sp. MT1962 produced 287 mM acetate (p < 0.005) and 293 mM ethanol (p < 0.005) fermenting synthesis gas blend 60% CO and 40% H₂ in single-stage continuous fermentation. This strain was metabolically engineered to the biocatalyst Clostridium sp. MTButOH1365. The engineered biocatalyst lost production of ethanol and acetate while initiated the production of 297 mM of n-butanol (p < 0.005). The metabolic engineering comprised Cre-lox66/lox71-based elimination of phosphotransacetylase and acetaldehyde dehydrogenase along with integration to chromosome synthetic thiolase, 3-hydroxy butyryl-CoA dehydrogenase, crotonase, butyryl-CoA dehydrogenase, butyraldehyde dehydrogenase, and NAD-dependent butanol dehydrogenase. This is the first report on elimination of acetate and ethanol production genes and expression of synthetic gene cluster encoding n-butanol biosynthesis pathway in acetogen biocatalyst for selective fuel n-butanol production with no antibiotic support for the introduced genes.

  5. Recovery of butanol from fermentation broth by pervaporation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butanol can be produced by fermentation from corn, molasses or lignocellulosic biomass for use as a chemical or superior biofuel. However, butanol’s production is hampered by its toxicity to the microbial culture that produces it. In fermentation broths, final butanol concentrations typically range ...

  6. Control of Carbon and Electron Flow in Clostridium acetobutylicum Fermentations: Utilization of Carbon Monoxide to Inhibit Hydrogen Production and to Enhance Butanol Yields

    PubMed Central

    Kim, Byung Hong; Bellows, Para; Datta, Rathin; Zeikus, J. G.

    1984-01-01

    Extracts prepared from non-solvent-producing cells of Clostridium acetobutylicum contained methyl viologen-linked hydrogenase activity (20 U/mg of protein at 37°C) but did not display carbon monoxide dehydrogenase activity. CO addition readily inhibited the hydrogenase activity of cell extracts or of viable metabolizing cells. Increasing the partial pressure of CO (2 to 10%) in unshaken anaerobic culture tube headspaces significantly inhibited (90% inhibition at 10% CO) both growth and hydrogen production by C. acetobutylicum. Growth was not sensitive to low partial pressures of CO (i.e., up to 15%) in pH-controlled fermentors (pH 4.5) that were continuously gassed and mixed. CO addition dramatically altered the glucose fermentation balance of C. acetobutylicum by diverting carbon and electrons away from H2, CO2, acetate, and butyrate production and towards production of ethanol and butanol. The butanol concentration was increased from 65 to 106 mM and the butanol productivity (i.e., the ratio of butanol produced/total acids and solvents produced) was increased by 31% when glucose fermentations maintained at pH 4.5 were continuously gassed with 85% N2-15% CO versus N2 alone. The results are discussed in terms of metabolic regulation of C. acetobutylicum saccharide fermentations to achieve maximal butanol or solvent yield. PMID:16346643

  7. Ethanol inhibits neuritogenesis induced by astrocyte muscarinic receptors.

    PubMed

    Guizzetti, Marina; Moore, Nadia H; Giordano, Gennaro; VanDeMark, Kathryn L; Costa, Lucio G

    2010-09-01

    In utero alcohol exposure can lead to fetal alcohol spectrum disorders, characterized by cognitive and behavioral deficits. In vivo and in vitro studies have shown that ethanol alters neuronal development. We have recently shown that stimulation of M(3) muscarinic receptors in astrocytes increases the synthesis and release of fibronectin, laminin, and plasminogen activator inhibitor-1, causing neurite outgrowth in hippocampal neurons. As M(3) muscarinic receptor signaling in astroglial cells is strongly inhibited by ethanol, we hypothesized that ethanol may also inhibit neuritogenesis in hippocampal neurons induced by carbachol-stimulated astrocytes. In the present study, we report that the effect of carbachol-stimulated astrocytes on hippocampal neuron neurite outgrowth was inhibited in a concentration-dependent manner (25-100 mM) by ethanol. This effect was because of the inhibition of the release of fibronectin, laminin, and plasminogen activator inhibitor-1. Similar effects on neuritogenesis and on the release of astrocyte extracellular proteins were observed after the incubation of astrocytes with carbachol in the presence of 1-butanol, another short-chain alcohol, which like ethanol is a competitive substrate for phospholipase D, but not by tert-butanol, its analog that is not a substrate for this enzyme. This study identifies a potential novel mechanism involved in the developmental effects of ethanol mediated by the interaction of ethanol with cell signaling in astrocytes, leading to an impairment in neuron-astrocyte communication.

  8. Fuel ethanol

    SciTech Connect

    Not Available

    1989-02-01

    This report discusses the Omnibus Trade and Competitiveness Act of 1988 which requires GAO to examine fuel ethanol imports from Central America and the Caribbean and their impact on the U.S. fuel ethanol industry. Ethanol is the alcohol in beverages, such as beer, wine, and whiskey. It can also be used as a fuel by blending with gasoline. It can be made from renewable resources, such as corn, wheat, grapes, and sugarcane, through a process of fermentation. This report finds that, given current sugar and gasoline prices, it is not economically feasible for Caribbean ethanol producers to meet the current local feedstock requirement.

  9. Antimutagenicity of an acetone extract of yogurt.

    PubMed

    Nadathur, S R; Gould, S J; Bakalinsky, A T

    1995-04-01

    Reconstituted non-fat dry milk powder, fermented by a mixture of Streptococcus thermophilus CH3 and Lactobacillus bulgaricus 191R to produce yogurt, was freeze-dried and extracted in acetone. After evaporation of the acetone, the extract was dissolved in dimethyl sulfoxide (DMSO) and tested for antimutagenicity. In the Ames test, significant dose-dependent activity was observed against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitro-quinoline-N-oxide (4NQO), 3,2'-dimethyl-4-aminobiphenyl (DMAB), 9,10-dimethyl-1,2-benz[a]anthracene (DMBA), and 3-amino-1-methyl-5H-pyrido[4,3-b]indole acetate (Trp-P-2). Weak activity was observed against 1,2,7,8-diepoxyoctane (DEO), and no activity was observed against methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS), or aflatoxin B1 (AFB1). In a related assay (Saccharomyces cerevisiae D7), significant antimutagenic activity was detected against MNNG and 4NQO. Activity against the experimental colon carcinogens MNNG and DMAB was examined further, as assayed in the Ames test (Salmonella typhimurium TA100). Compounds responsible for both activities were less soluble in aqueous solutions than in DMSO. Adjustment of yogurt pH to 3, 7.6, or 13 prior to freeze-drying and acetone extraction did not significantly alter the amount of anti-MNNG activity recovered. In contrast, extractability of anti-DMAB activity was significantly greater at acidic pH. Conjugated linoleic acid, a known dairy anticarcinogen, failed to inhibit mutagenesis caused by either mutagen, suggesting that other yogurt-derived compound(s) are responsible. Unfermented milk was treated with lactic acid, yogurt bacteria without subsequent growth, or both, to determine if formation of antimutagenic activity required bacterial growth. Extracts of the milk treatments exhibited the same weak antimutagenicity observed in unfermented milk, approximately 2.5-fold less than in the yogurt extracts, suggesting that antimutagenic activity is associated with bacterial

  10. Enhanced butanol fermentation using metabolically engineered Clostridium acetobutylicum with ex situ recovery of butanol.

    PubMed

    Lee, Sang-Hyun; Kim, Sooah; Kim, Jung Yeon; Cheong, Nam Yong; Kim, Kyoung Heon

    2016-10-01

    In this study, metabolic target reactions for strain engineering were searched via intracellular coenzyme A (CoA) metabolite analysis. The metabolic reactions catalyzed by thiolase (AtoB) and aldehyde-alcohol dehydrogenase (AdhE1) were considered potential rate-limiting steps. In addition, CoA transferase (CtfAB) was highlighted as being important for the assimilation of organic acids, in order to achieve high butanol production. Based on this quantitative analysis, the BEKW_E1AB-atoB strain was constructed by overexpressing the thl (atoB), adhE1, and ctfAB genes in Clostridium acetobutylicum strain BEKW, which has the phosphotransacetylase (pta) and butyrate kinase (buk) genes knocked out. After 100h of continuous fermentation coupled with adsorptive ex situ butanol recovery, the concentrations found after considering desorption, yield, and productivity for the BEKW_E1AB-atoB strain were 55.7g/L, 0.38g/g, and 2.64g/L/h, respectively. The level of butanol production achieved (2.64g/L/h) represents the highest reported value obtained after adsorptive, long-term fermentation.

  11. Acetone in theGlobal Troposphere: Its Possible Role as a Global Source of PAN

    NASA Technical Reports Server (NTRS)

    Singh, H. B.; Kanakidou, M.

    1994-01-01

    Oxygenated hydrocarbons are thought to be important components of the atmosphere but, with the exception of formaldehyde, very little about their distribution and fate is known. Aircraft measurements of acetone (CH3COCH3), PAN (CH3CO3NO2) and other organic species (e. g. acetaldehyde, methanol and ethanol) have been performed over the Pacific, the southern Atlantic, and the subarctic atmospheres. Sampled areas extended from 0 to 12 km altitude over latitudes of 70 deg N to 40 deg S. All measurements are based on real time in-situ analysis of cryogenically preconcentrated air samples. Substantial concentrations of these oxygenated species (10-2000 ppt) have been observed at all altitudes and geographical locations in the troposphere. Important sources include, emissions from biomass burning, plant and vegetation, secondary oxidation of primary non-methane hydrocarbons, and man-made emissions. Direct measurements within smoke plumes have been used to estimate the biomass burning source. Photochemistry studies are used to suggest that acetone could provide a major source of peroxyacetyl radicals in the atmosphere and play an important role in sequestering reactive nitrogen. Model calculations show that acetone photolysis contributes significantly to PAN formation in the middle and upper troposphere.

  12. Direct hydrogenation of biomass-derived butyric acid to n-butanol over a ruthenium-tin bimetallic catalyst.

    PubMed

    Lee, Jong-Min; Upare, Pravin P; Chang, Jong-San; Hwang, Young Kyu; Lee, Jeong Ho; Hwang, Dong Won; Hong, Do-Young; Lee, Seung Hwan; Jeong, Myung-Geun; Kim, Young Dok; Kwon, Young-Uk

    2014-11-01

    Catalytic hydrogenation of organic carboxylic acids and their esters, for example, cellulosic ethanol from fermentation of acetic acid and hydrogenation of ethyl acetate is a promising possibility for future biorefinery concepts. A hybrid conversion process based on selective hydrogenation of butyric acid combined with fermentation of glucose has been developed for producing biobutanol. ZnO-supported Ru-Sn bimetallic catalysts exhibits unprecedentedly superior performance in the vapor-phase hydrogenation of biomass-derived butyric acid to n-butanol (>98% yield) for 3500 h without deactivation.

  13. Apparatus and method for monitoring breath acetone and diabetic diagnostics

    DOEpatents

    Duan, Yixiang; Cao, Wenqing

    2008-08-26

    An apparatus and method for monitoring diabetes through breath acetone detection and quantitation employs a microplasma source in combination with a spectrometer. The microplasma source provides sufficient energy to produce excited acetone fragments from the breath gas that emit light. The emitted light is sent to the spectrometer, which generates an emission spectrum that is used to detect and quantify acetone in the breath gas.

  14. Higher-alcohols biorefinery: improvement of catalyst for ethanol conversion.

    PubMed

    Olson, Edwin S; Sharma, Ramesh K; Aulich, Ted R

    2004-01-01

    The concept of a biorefinery for higher-alcohol production is to integrate ethanol and methanol formation via fermentation and biomass gasification, respectively, with conversion of these simple alcohol intermediates into higher alcohols via the Guerbet reaction. 1-Butanol results from the self-condensation of ethanol in this multistep reaction occurring on a single catalytic bed. Combining methanol with ethanol gives a mixture of propanol, isobutanol, and 2-methyl-1-butanol. All of these higher alcohols are useful as solvents, chemical intermediates, and fuel additives and, consequently, have higher market values than the simple alcohol intermediates. Several new catalysts for the condensation of ethanol and alcohol mixtures to higher alcohols were designed and tested under a variety of conditions. Reactions of methanol-ethanol mixtures gave as high as 100% conversion of the ethanol to form high yields of isobutanol with smaller amounts of 1-propanol, the amounts in the mixture depending on the starting mixture. The most successful catalysts are multifunctional with basic and hydrogen transfer components.

  15. Comparative shotgun proteomic analysis of Clostridium acetobutylicum from butanol fermentation using glucose and xylose

    SciTech Connect

    Sivagnanam, Kumaran; Raghavan, Vijaya G. S.; Shah, Manesh B; Hettich, Robert {Bob} L; Verberkmoes, Nathan C; Lefsrud, Mark G

    2011-01-01

    Background: Butanol is a second generation biofuel produced by Clostridium acetobutylicum through acetonebutanol- ethanol (ABE) fermentation process. Shotgun proteomics provides a direct approach to study the whole proteome of an organism in depth. This paper focuses on shotgun proteomic profiling of C. acetobutylicum from ABE fermentation using glucose and xylose to understand the functional mechanisms of C. acetobutylicum proteins involved in butanol production. Results: We identified 894 different proteins in C. acetobutylicum from ABE fermentation process by two dimensional - liquid chromatography - tandem mass spectrometry (2D-LC-MS/MS) method. This includes 717 proteins from glucose and 826 proteins from the xylose substrate. A total of 649 proteins were found to be common and 22 significantly differentially expressed proteins were identified between glucose and xylose substrates. Conclusion: Our results demonstrate that flagellar proteins are highly up-regulated with glucose compared to xylose substrate during ABE fermentation. Chemotactic activity was also found to be lost with the xylose substrate due to the absence of CheW and CheV proteins. This is the first report on the shotgun proteomic analysis of C. acetobutylicum ATCC 824 in ABE fermentation between glucose and xylose substrate from a single time data point and the number of proteins identified here is more than any other study performed on this organism up to this report.

  16. IRIS Toxicological Review of n-Butanol (External Review Draft)

    EPA Science Inventory

    EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of n-butanol that will appear in the Integrated Risk Information System (IRIS) database.

  17. Total flavonoid and phenolic contents of n-butanol extract of Samanea saman leaf and the antibacterial activity towards Escherichia coli and Staphylococcus aureus

    NASA Astrophysics Data System (ADS)

    Rita, Wiwik Susanah; Swantara, I. Made Dira; Asih, I. A. Raka Astiti; Sinarsih, Ni Ketut; Suteja, I. Kadek Pater

    2016-03-01

    Total flavonoid and phenolic contents in some natural products was suspected of having a positive correlation to its activity in inhibiting the growth of bacteria. The aim of this study was to determine the total flavonoid and phenolic contents of n-butanol extract of Samanea saman leaf, and to evaluate the antibacterial activity towards Escherechia coli and Staphylococcus aureus. Extraction of compounds was done by ethanol 96%, followed by fractionation into n-hexane, ethyl acetate, and n-butanol. Determination of total flavonoid and phenolic contents was done by UV-Vis Spectrophotometer using standard of quersetin and galic acid respectively. In addition, antibacterial activity was evaluated by agar disc diffusion method. Extraction of 1000 g of Samanea saman leaf was obtained 80 g of ethanol extracts, fractionation of the extract was obtained 8.02 g of n-hexane extracts, 7.11 g of ethyl acetate extracts, 13.5 g of n-butanol extracts, and 14.16 g of aqueous extracts. Phytochemical screening of the n-butanol extracts revealed the presence of flavonoid and phenolic compounds. Total flavonoid and phenolic contents were successively 43.5798 mg QE/100g and 34.0180 mg GAE/100g. The butanol extracts inhibited the growth of S.aureus higher than the growth of E.coli. At the concentration of 2, 4, 6, 8 % (b/v), and positive control (meropenem μg/disc), inhibition zone towards S. aureus was successively 5.67, 9.33, 10.33, 12.00, and 32.33 mm, while the inhibition zone towards E. coli was1.33, 3.33, 4.33, 5.43, and 34.00 mm.

  18. Temperature Dependence of Densities and Excess Molar Volumes of the Ternary Mixture (1-Butanol + Chloroform + Benzene) and its Binary Constituents (1-Butanol + Chloroform and 1-Butanol + Benzene)

    NASA Astrophysics Data System (ADS)

    Smiljanić, Jelena D.; Kijevčanin, Mirjana Lj.; Djordjević, Bojan D.; Grozdanić, Dušan K.; Šerbanović, Slobodan P.

    2008-04-01

    Densities ρ of the 1-butanol + chloroform + benzene ternary mixture and the 1-butanol + chloroform and 1-butanol + benzene binaries have been measured at six temperatures (288.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K and atmospheric pressure, using an oscillating U-tube densimeter. From these densities, excess molar volumes ( V E) were calculated and fitted to the Redlich Kister equation for all binary mixtures and to the Nagata and Tamura equation for the ternary system. The Radojković et al. equation has been used to predict excess molar volumes of the ternary mixtures. Also, V E data of the binary systems were correlated by the van der Waals (vdW1) and Twu Coon Bluck Tilton (TCBT) mixing rules coupled with the Peng Robinson Stryjek Vera (PRSV) equation of state. The prediction and correlation of V E data for the ternary system were performed by the same models.

  19. Dissociative electron attachment studies on acetone

    NASA Astrophysics Data System (ADS)

    Prabhudesai, Vaibhav S.; Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E.

    2014-10-01

    Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0-20 eV. H- is found to be the most dominant fragment followed by O- and OH- with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H- and O- fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance.

  20. Dissociative electron attachment studies on acetone

    SciTech Connect

    Prabhudesai, Vaibhav S. Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E.

    2014-10-28

    Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0–20 eV. H{sup −} is found to be the most dominant fragment followed by O{sup −} and OH{sup −} with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H{sup −} and O{sup −} fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance.

  1. Effect of Cobalt Particle Size on Acetone Steam Reforming

    SciTech Connect

    Sun, Junming; Zhang, He; Yu, Ning; Davidson, Stephen; Wang, Yong

    2015-06-11

    Carbon-supported cobalt nanoparticles with different particle sizes were synthesized and characterized by complementary characterization techniques such as X-ray diffraction, N-2 sorption, acetone temperature-programmed desorption, transmission electron microscopy, and CO chemisorption. Using acetone steam reforming reaction as a probe reaction, we revealed a volcano-shape curve of the intrinsic activity (turnover frequency of acetone) and the CO2 selectivity as a function of the cobalt particle size with the highest activity and selectivity observed at a particle size of approximately 12.8nm. Our results indicate that the overall performance of acetone steam reforming is related to a combination of particle-size-dependent acetone decomposition, water dissociation, and the oxidation state of the cobalt nanoparticles.

  2. 3-Methyl-1-butanol Biosynthesis in an Engineered Corynebacterium glutamicum.

    PubMed

    Xiao, Shiyuan; Xu, Jingliang; Chen, Xiaoyan; Li, Xiekun; Zhang, Yu; Yuan, Zhenhong

    2016-05-01

    Biofuel offers a promising solution to the adverse environmental problems and depletion in reserves of fossil fuels. Higher alcohols including 3-methyl-1-butanol were paid much more attention as fuel substitute in recent years, due to its similar properties to gasoline. In the present work, 3-methyl-1-butanol production in engineered Corynebacterium glutamicum was studied. α-Ketoisovalerate decarboxylase gene (kivd) from Lactococcus lactis combined with alcohol dehydrogenase gene (adh2, adhA, and adh3) from three organisms were overexpressed in C. glutamicum. Enzymatic assay and alcohol production results showed that adh3 from Zymomonas mobilis was the optimum candidate for 3-methyl-1-butanol production in C. glutamicum. The recombinant with kivd and adh3 could produce 0.182 g/L of 3-methyl-1-butanol and 0.144 g/L of isobutanol after 12 h of incubation. Further inactivation of the E1 subunit of pyruvate dehydrogenase complex gene (aceE) and lactic dehydrogenase gene (ldh) in the above C. glutamicum strain would improve the 3-Methyl-1-butanol titer to 0.497 g/L after 12 h of incubation.

  3. Measuring breath acetone for monitoring fat loss: Review

    PubMed Central

    2015-01-01

    Objective Endogenous acetone production is a by‐product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in predicting fat loss and its sensitivity to changes in physiologic parameters. Results BrAce can range from 1 ppm in healthy non‐dieting subjects to 1,250 ppm in diabetic ketoacidosis. A strong correlation exists between increased BrAce and the rate of fat loss. Multiple metabolic and respiratory factors affect the measurement of BrAce. BrAce is most affected by changes in the following factors (in descending order): dietary macronutrient composition, caloric restriction, exercise, pulmonary factors, and other assorted factors that increase fat metabolism or inhibit acetone metabolism. Pulmonary factors affecting acetone exchange in the lung should be controlled to optimize the breath sample for measurement. Conclusions When biologic factors are controlled, BrAce measurement provides a non‐invasive tool for monitoring the rate of fat loss in healthy subjects. PMID:26524104

  4. An Acetone Nanosensor For Non-invasive Diabetes Detection

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yun, X.; Stanacevic, M.; Gouma, P. I.

    2009-05-01

    Diabetes is a most common disease worldwide. Acetone in exhaled breath is a known biomarker of Type- 1 diabetes. An exhaled breath analyzer has been developed with the potential to diagnose diabetes as a non-invasive alternative of the currently used blood-based diagnostics. This device utilizes a chemiresistor based on ferroelectric tungsten oxide nanoparticles and detects acetone selectively in breath-simulated media. Real-time monitoring of the acetone concentration is feasible, potentially making this detector a revolutionary, non- invasive, diabetes diagnostic tool.

  5. Nonpremixed ignition, laminar flame propagation, and mechanism reduction of n-butanol, iso-butanol, and methyl butanoate

    SciTech Connect

    Lu, Wei; Kelley, A. P.; Law, C. K.

    2011-01-01

    The non-premixed ignition temperature of n-butanol (CH{sub 3}CH{sub 2}CH{sub 2}CH{sub 2}OH), iso-butanol ((CH{sub 3}){sub 2}CHCH{sub 2}OH) and methyl butanoate (CH{sub 3}CH{sub 2}CH{sub 2}COOCH{sub 3}) was measured in a liquid pool assembly by heated oxidizer in a stagnation flow for system pressures of 1 and 3 atm. In addition, the stretch-corrected laminar flame speeds of mixtures of air–n-butanol/iso-butanol/methyl butanoate were determined from the outwardly propagating spherical flame at initial pressures of up to 2 atm, for an extensive range of equivalence ratio. The ignition temperature and laminar flame speeds of n-butanol and methyl butanoate were computationally simulated with three recently developed kinetic mechanisms in the literature. Dominant reaction pathways to ignition and flame propagation were identified and discussed through a chemical explosive mode analysis (CEMA) and sensitivity analysis. The detailed models were further reduced through a series of systematic strategies. The reduced mechanisms provided excellent agreement in both homogeneous and diffusive combustion environments and greatly improved the computation efficiency.

  6. Development of a high temperature microbial fermentation process for butanol

    SciTech Connect

    Jeor, Jeffery D. St.; Reed, David W.; Daubaras, Dayna L.; Thompson, Vicki S.

    2015-08-01

    Transforming renewable biomass into cost-competitive high-performance biofuels and bioproducts is key to the U.S. future energy and chemical needs. Butanol production by microbial fermentation for chemical conversion to polyolefins, elastomers, drop-in jet or diesel fuel, and other chemicals is a promising solution. A high temperature fermentation process could decrease energy costs, capital cost, give higher butanol production, and allow for continuous fermentation. In this paper, we describe our approach to genetically transform Geobacillus caldoxylosiliticus, using a pUCG18 plasmid, for potential insertion of a butanol production pathway. Transformation methods tested were electroporation of electrocompetent cells, ternary conjugation with E. coli donor and helper strains, and protoplast fusion. These methods have not been successful using the current plasmid. Growth controls show cells survive the various methods tested, suggesting the possibility of transformation inhibition from a DNA restriction modification system in G. caldoxylosiliticus, as reported in the literature.

  7. Frontiers in microbial 1-butanol and isobutanol production.

    PubMed

    Chen, Chang-Ting; Liao, James C

    2016-03-01

    The heavy dependence on petroleum-derived fuel has raised concerns about energy sustainability and climate change, which have prompted researchers to explore fuel production from renewable sources. 1-Butanol and isobutanol are promising biofuels that have favorable properties and can also serve as solvents or chemical feedstocks. Microbial production of these alcohols provides great opportunities to access a wide spectrum of renewable resources. In recent years, research has improved the native 1-butanol production and has engineered isobutanol production in various organisms to explore metabolic diversity and a broad range of substrates. This review focuses on progress in metabolic engineering for the production of these two compounds using various resources.

  8. Potential biofuel additive from renewable sources--Kinetic study of formation of butyl acetate by heterogeneously catalyzed transesterification of ethyl acetate with butanol.

    PubMed

    Ali, Sami H; Al-Rashed, Osama; Azeez, Fadhel A; Merchant, Sabiha Q

    2011-11-01

    Butyl acetate holds great potential as a sustainable biofuel additive. Heterogeneously catalyzed transesterification of biobutanol and bioethylacetate can produce butyl acetate. This route is eco-friendly and offers several advantages over the commonly used Fischer Esterification. The Amberlite IR 120- and Amberlyst 15-catalyzed transesterification is studied in a batch reactor over a range of catalyst loading (6-12 wt.%), alcohol to ester feed ratio (1:3 to 3:1), and temperature (303.15-333.15K). A butanol mole fraction of 0.2 in the feed is found to be optimum. Amberlite IR 120 promotes faster kinetics under these conditions. The transesterifications studied are slightly exothermic. The moles of solvent sorbed per gram of catalyst decreases (ethanol>butanol>ethyl acetate>butyl acetate) with decrease in solubility parameter. The dual site models, the Langmuir Hinshelwood and Popken models, are the most successful in correlating the kinetics over Amberlite IR 120 and Amberlyst 15, respectively.

  9. Toward Portable Breath Acetone Analysis for Diabetes Detection

    PubMed Central

    Righettoni, Marco; Tricoli, Antonio

    2013-01-01

    Diabetes is a lifelong condition that may cause death and seriously affects the quality of life of a rapidly growing number of individuals. Acetone is a selective breath marker for diabetes that may contribute to the monitoring of related metabolic disorder and thus simplify the management of this illness. Here, the overall performance of Si-doped WO3 nanoparticles made by flame spray pyrolysis as portable acetone detectors is critically reviewed focusing on the requirements for medical diagnostic. The effect of flow rate, chamber volume and acetone dissociation within the measuring chamber are discussed with respect to the calibration of the sensor response. The challenges for the fabrication of portable breath acetone sensors based on chemo-resistive detectors are underlined indicating possible solutions and novel research directions. PMID:21828897

  10. New Insights into Reaction Mechanisms of Ethanol Steam Reforming on Co-ZrO2

    SciTech Connect

    Sun, Junming; Karim, Ayman M.; Mei, Donghai; Engelhard, Mark H.; Bao, Xinhe; Wang, Yong

    2015-01-01

    The reaction pathway of ethanol steam reforming on Co-ZrO2 has been identified and the active sites associated with each step are proposed. Ethanol is converted to acetaldehyde and then to acetone, followed by acetone steam reforming. More than 90% carbon was found to follow this reaction pathway. N2-Sorption, X-ray Diffraction (XRD), Temperature Programmed Reduction (TPR), in situ X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy, as well as theoretical Density Functional Theory (DFT) calculations have been employed to identify the structure and functionality of the catalysts, which was further used to correlate their performance in ESR. It was found that metallic cobalt is mainly responsible for the acetone steam reforming reactions; while, CoO and basic sites on the support play a key role in converting ethanol to acetone via dehydrogenation and condensation/ketonization reaction pathways. The current work provides fundamental understanding of the ethanol steam reforming reaction mechanisms on Co-ZrO2 catalysts and sheds light on the rational design of selective and durable ethanol steam reforming catalysts.

  11. The Sensing Properties of Single Y-Doped SnO2 Nanobelt Device to Acetone.

    PubMed

    Li, Xinmin; Liu, Yingkai; Li, Shuanghui; Huang, Jieqing; Wu, Yuemei; Yu, Dapeng

    2016-12-01

    Pure SnO2 and Y-doped SnO2 nanobelts were prepared by thermal evaporation at 1350 °C in the presence of Ar carrier gas (30 sccm). The samples were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersion spectrometer (EDS), X-ray photoelectron spectrometer (XPS), UV-Vis absorption spectroscopy, Raman spectroscopy, and Fourier transform infrared spectrum (FTIR). The sensing properties of the devices based on a single SnO2 nanobelt and Y-doped SnO2 nanobelt were explored to acetone, ethanol, and ethanediol. It reveals that the sensitivity of single Y-doped SnO2 nanobelt device is 11.4 to 100 ppm of acetone at 210 °C, which is the highest response among the three tested VOC gases. Y(3+) ions improve the sensitivity of SnO2 sensor and have an influence on the optical properties of Y-doped SnO2 nanobelts.

  12. Secondary alcohol dehydrogenase catalyzes the reduction of exogenous acetone to 2-propanol in Trichomonas vaginalis.

    PubMed

    Sutak, Robert; Hrdy, Ivan; Dolezal, Pavel; Cabala, Radomir; Sedinová, Miroslava; Lewin, Joern; Harant, Karel; Müller, Miklos; Tachezy, Jan

    2012-08-01

    Secondary alcohols such as 2-propanol are readily produced by various anaerobic bacteria that possess secondary alcohol dehydrogenase (S-ADH), although production of 2-propanol is rare in eukaryotes. Specific bacterial-type S-ADH has been identified in a few unicellular eukaryotes, but its function is not known and the production of secondary alcohols has not been studied. We purified and characterized S-ADH from the human pathogen Trichomonas vaginalis. The kinetic properties and thermostability of T. vaginalis S-ADH were comparable with bacterial orthologues. The substantial activity of S-ADH in the parasite's cytosol was surprising, because only low amounts of ethanol and trace amounts of secondary alcohols were detected as metabolic end products. However, S-ADH provided the parasite with a high capacity to scavenge and reduce external acetone to 2-propanol. To maintain redox balance, the demand for reducing power to metabolize external acetone was compensated for by decreased cytosolic reduction of pyruvate to lactate and by hydrogenosomal metabolism of pyruvate. We speculate that hydrogen might be utilized to maintain cytosolic reducing power. The high activity of Tv-S-ADH together with the ability of T. vaginalis to modulate the metabolic fluxes indicate efficacious metabolic responsiveness that could be advantageous for rapid adaptation of the parasite to changes in the host environment.

  13. Acetone sensor based on zinc oxide hexagonal tubes

    SciTech Connect

    Hastir, Anita Singh, Onkar Anand, Kanika Singh, Ravi Chand

    2014-04-24

    In this work hexagonal tubes of zinc oxide have been synthesized by co-precipitation method. For structural, morphological, elemental and optical analysis synthesized powders were characterized by using x-ray diffraction, field emission scanning microscope, EDX, UV-visible and FTIR techniques. For acetone sensing thick films of zinc oxide have been deposited on alumina substrate. The fabricated sensors exhibited maximum sensing response towards acetone vapour at an optimum operating temperature of 400°C.

  14. 40 CFR 721.10162 - 1,3 Dioxolane-4-butanol, 2-ethenyl-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1,3 Dioxolane-4-butanol, 2-ethenyl... Specific Chemical Substances § 721.10162 1,3 Dioxolane-4-butanol, 2-ethenyl-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,3 dioxolane-4-butanol,...

  15. 40 CFR 721.10162 - 1,3 Dioxolane-4-butanol, 2-ethenyl-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 1,3 Dioxolane-4-butanol, 2-ethenyl... Specific Chemical Substances § 721.10162 1,3 Dioxolane-4-butanol, 2-ethenyl-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,3 dioxolane-4-butanol,...

  16. 40 CFR 721.10162 - 1,3 Dioxolane-4-butanol, 2-ethenyl-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 1,3 Dioxolane-4-butanol, 2-ethenyl... Specific Chemical Substances § 721.10162 1,3 Dioxolane-4-butanol, 2-ethenyl-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,3 dioxolane-4-butanol,...

  17. 40 CFR 721.10162 - 1,3 Dioxolane-4-butanol, 2-ethenyl-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 1,3 Dioxolane-4-butanol, 2-ethenyl... Specific Chemical Substances § 721.10162 1,3 Dioxolane-4-butanol, 2-ethenyl-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,3 dioxolane-4-butanol,...

  18. 40 CFR 721.10162 - 1,3 Dioxolane-4-butanol, 2-ethenyl-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 1,3 Dioxolane-4-butanol, 2-ethenyl... Specific Chemical Substances § 721.10162 1,3 Dioxolane-4-butanol, 2-ethenyl-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,3 dioxolane-4-butanol,...

  19. Bioconversion of lignocellulose to butanol (a superior fuel) and process technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Economic studies on bioconversion of corn to butanol have demonstrated that substrate cost affects butanol price most. Hence, to produce butanol cost competitively, more economical substrates should be used. Additionally, process technologies, such as reactor designs and energy efficient product re...

  20. 76 FR 25362 - Cooperative Research and Development Agreement: Butanol Fuel Blend Usage With Marine Outboard...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... SECURITY Coast Guard Cooperative Research and Development Agreement: Butanol Fuel Blend Usage With Marine... Agreement (CRADA) to identify and investigate the use of butanol fuel blends within marine outboard engines... butanol fuel blends with marine outboard engines, with the overarching goal of reducing their...

  1. Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria.

    PubMed

    Heider, Johann; Schühle, Karola; Frey, Jasmin; Schink, Bernhard

    2016-01-01

    Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO2-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions.

  2. Modeling microbial ethanol production by E. coli under aerobic/anaerobic conditions: applicability to real postmortem cases and to postmortem blood derived microbial cultures.

    PubMed

    Boumba, Vassiliki A; Kourkoumelis, Nikolaos; Gousia, Panagiota; Economou, Vangelis; Papadopoulou, Chrissanthy; Vougiouklakis, Theodore

    2013-10-10

    The mathematical modeling of the microbial ethanol production under strict anaerobic experimental conditions for some bacterial species has been proposed by our research group as the first approximation to the quantification of the microbial ethanol production in cases where other alcohols were produced simultaneously with ethanol. The present study aims to: (i) study the microbial ethanol production by Escherichia coli under controlled aerobic/anaerobic conditions; (ii) model the correlation between the microbial produced ethanol and the other higher alcohols; and (iii) test their applicability in: (a) real postmortem cases that had positive BACs (>0.10 g/L) and co-detection of higher alcohols and 1-butanol during the original ethanol analysis and (b) postmortem blood derived microbial cultures under aerobic/anaerobic controlled experimental conditions. The statistical evaluation of the results revealed that the formulated models were presumably correlated to 1-propanol and 1-butanol which were recognized as the most significant descriptors of the modeling process. The significance of 1-propanol and 1-butanol as descriptors was so powerful that they could be used as the only independent variables to create a simple and satisfactory model. The current models showed a potential for application to estimate microbial ethanol - within an acceptable standard error - in various tested cases where ethanol and other alcohols have been produced from different microbes.

  3. Mutant strain of C. acetobutylicum and process for making butanol

    DOEpatents

    Jain, Mahendra K.; Beacom, Daniel; Datta, Rathin

    1993-01-01

    A biologically pure asporogenic mutant of Clostridium acetobutylicum is produced by growing sporogenic C. acetobutylicum ATCC 4259 and treating the parent strain with ethane methane sulfonate. The mutant which as been designated C. acetobutylicum ATCC 55025 is useful in an improved ABE fermentation process, and produces high concentrations of butanol and total solvents.

  4. Quantitative Clinical Diagnostic Analysis of Acetone in Human Blood by HPLC: A Metabolomic Search for Acetone as Indicator

    PubMed Central

    Akgul Kalkan, Esin; Sahiner, Mehtap; Ulker Cakir, Dilek; Alpaslan, Duygu; Yilmaz, Selehattin

    2016-01-01

    Using high-performance liquid chromatography (HPLC) and 2,4-dinitrophenylhydrazine (2,4-DNPH) as a derivatizing reagent, an analytical method was developed for the quantitative determination of acetone in human blood. The determination was carried out at 365 nm using an ultraviolet-visible (UV-Vis) diode array detector (DAD). For acetone as its 2,4-dinitrophenylhydrazone derivative, a good separation was achieved with a ThermoAcclaim C18 column (15 cm × 4.6 mm × 3 μm) at retention time (tR) 12.10 min and flowrate of 1 mL min−1 using a (methanol/acetonitrile) water elution gradient. The methodology is simple, rapid, sensitive, and of low cost, exhibits good reproducibility, and allows the analysis of acetone in biological fluids. A calibration curve was obtained for acetone using its standard solutions in acetonitrile. Quantitative analysis of acetone in human blood was successfully carried out using this calibration graph. The applied method was validated in parameters of linearity, limit of detection and quantification, accuracy, and precision. We also present acetone as a useful tool for the HPLC-based metabolomic investigation of endogenous metabolism and quantitative clinical diagnostic analysis. PMID:27298750

  5. Study of butanol extraction through pervaporation in acetobutylic fermentation

    SciTech Connect

    Larrayoz, M.A.; Puigjaner, L.

    1987-01-01

    Substrates conversion during acetobutylic fermentation is essentially limited by the concentration of butanol in the fermentation medium, since butanol itself a by-product of this process. Butanol concentrations of 14-16 g/L inhibit bacterial growth, thereby limiting glucose consumption between 60 and 70 g/L. Thus, there is a limit to the amount of usable substrate beyond which the inhibiting level of butanol is reached, leaving unconverted substrate in the fermentaion medium. One way to reduce this effect would be by in situ extraction of the inhibiting product, thus increasing substrate conversion into products once the inhibiting effect in the bacteria has been removed. Different alternatives such as liquid-liquid extraction in anaerobic systems have been proposed. However, these methods have not been sufficiently developed since most of the solvents utilized for extraction are toxic to bacteria, and those which are not present the inconvenience of a very low solvent-butanol distribution coefficient. In most cases, the separation of organic compounds is carried out at the industrial level using distillation, which is very expensive in terms of energy consumption. On the other hand, membrane separation systems are rather promising processes due to their low energetic cost and to the fact that they have been widely developed in several industrial areas, such as salt water desalinitation, oxygen-rich air production etc. Nevertheless, separation of neutral organic compounds cannot be achieved using the techniques, since they are based on properties such as ionization indices which are not present in neutral moleules. Pervaporation makes possible the separation of different organic compounds. Pervaporation is a process in which organic compounds diffuse through a membrane. Therefore, this technique may be used if the components of a mixture show different membrane diffusion rates.

  6. Acetone production with metabolically engineered strains of Acetobacterium woodii.

    PubMed

    Hoffmeister, Sabrina; Gerdom, Marzena; Bengelsdorf, Frank R; Linder, Sonja; Flüchter, Sebastian; Öztürk, Hatice; Blümke, Wilfried; May, Antje; Fischer, Ralf-Jörg; Bahl, Hubert; Dürre, Peter

    2016-07-01

    Expected depletion of oil and fossil resources urges the development of new alternative routes for the production of bulk chemicals and fuels beyond petroleum resources. In this study, the clostridial acetone pathway was used for the formation of acetone in the acetogenic bacterium Acetobacterium woodii. The acetone production operon (APO) containing the genes thlA (encoding thiolase A), ctfA/ctfB (encoding CoA transferase), and adc (encoding acetoacetate decarboxylase) from Clostridium acetobutylicum were cloned under the control of the thlA promoter into four vectors having different replicons for Gram-positives (pIP404, pBP1, pCB102, and pCD6). Stable replication was observed for all constructs. A. woodii [pJIR_actthlA] achieved the maximal acetone concentration under autotrophic conditions (15.2±3.4mM). Promoter sequences of the genes ackA from A. woodii and pta-ack from C. ljungdahlii were determined by primer extension (PEX) and cloned upstream of the APO. The highest acetone production in recombinant A. woodii cells was achieved using the promoters PthlA and Ppta-ack. Batch fermentations using A. woodii [pMTL84151_actthlA] in a bioreactor revealed that acetate concentration had an effect on the acetone production, due to the high Km value of the CoA transferase. In order to establish consistent acetate concentration within the bioreactor and to increase biomass, a continuous fermentation process for A. woodii was developed. Thus, acetone productivity of the strain A. woodii [pMTL84151_actthlA] was increased from 1.2mgL(-1)h(-1) in bottle fermentation to 26.4mgL(-1)h(-1) in continuous gas fermentation.

  7. Quantitative proteomics reveals dynamic responses of Synechocystis sp. PCC 6803 to next-generation biofuel butanol.

    PubMed

    Tian, Xiaoxu; Chen, Lei; Wang, Jiangxin; Qiao, Jianjun; Zhang, Weiwen

    2013-01-14

    Butanol is a promising biofuel, and recent metabolic engineering efforts have demonstrated the use of photosynthetic cyanobacterial hosts for its production. However, cyanobacteria have very low tolerance to butanol, limiting the economic viability of butanol production from these renewable producing systems. The existing knowledge of molecular mechanism involved in butanol tolerance in cyanobacteria is very limited. To build a foundation necessary to engineer robust butanol-producing cyanobacterial hosts, in this study, the responses of Synechocystis PCC 6803 to butanol were investigated using a quantitative proteomics approach with iTRAQ - LC-MS/MS technologies. The resulting high-quality dataset consisted of 25,347 peptides corresponding to 1452 unique proteins, a coverage of approximately 40% of the predicted proteins in Synechocystis. Comparative quantification of protein abundances led to the identification of 303 differentially regulated proteins by butanol. Annotation and GO term enrichment analysis showed that multiple biological processes were regulated, suggesting that Synechocystis probably employed multiple and synergistic resistance mechanisms in dealing with butanol stress. Notably, the analysis revealed the induction of heat-shock protein and transporters, along with modification of cell membrane and envelope were the major protection mechanisms against butanol. A conceptual cellular model of Synechocystis PCC 6803 responses to butanol stress was constructed to illustrate the putative molecular mechanisms employed to defend against butanol stress.

  8. Biological butanol production from microalgae-based biodiesel residues by Clostridium acetobutylicum.

    PubMed

    Cheng, Hai-Hsuan; Whang, Liang-Ming; Chan, Kun-Chi; Chung, Man-Chien; Wu, Shu-Hsien; Liu, Cheng-Pin; Tien, Shih-Yuan; Chen, Shan-Yuan; Chang, Jo-Shu; Lee, Wen-Jhy

    2015-05-01

    This study conducted batch experiments to evaluate the potential of butanol production from microalgae biodiesel residues by Clostridium acetobutylicum. The results indicated that with 90 g/L of glucose as the sole substrate the highest butanol yield of 0.2 g/g-glucose was found, but the addition of butyrate significantly enhanced the butanol yield. The highest butanol yield of 0.4 g/g-glucose was found with 60 g/L of glucose and 18 g/L of butyrate. Using microalgae biodiesel residues as substrate, C. acetobutylicum produced 3.86 g/L of butanol and achieved butanol yield of 0.13 g/g-carbohydrate via ABE fermentation, but the results indicated that approximately one third of carbohydrate was not utilized by C. acetobutylicum. Biological butanol production from microalgae biodiesel residues can be possible, but further research on fermentation strategies are required to improve production yield.

  9. Optimization of fermentation condition favoring butanol production from glycerol by Clostridium pasteurianum DSM 525.

    PubMed

    Sarchami, Tahereh; Johnson, Erin; Rehmann, Lars

    2016-05-01

    Butanol is a promising biofuel and valuable platform chemical that can be produced through fermentative conversion of glycerol. The initial fermentation conditions for butanol production from pure glycerol by Clostridium pasteurianum DSM 525 were optimized via a central composite design. The effect of inoculum age, initial cell density, initial pH of medium and temperature were quantified and a quadratic model was able to predict butanol yield as a function of all four investigated factors. The model was confirmed through additional experiments and via analysis of variance (ANOVA). Subsequently, numerical optimization was used to maximize the butanol yield within the experimental range. Based on these results, batch fermentations in a 7 L bioreactor were performed using pure and crude (residue from biodiesel production) glycerol as substrates at optimized conditions. A butanol yield of 0.34 mole(butanol) mole(-1)(glycerol) was obtained indicating the suitability of this feedstock for fermentative butanol production.

  10. Biogenic and biomass burning sources of acetone to the troposphere

    SciTech Connect

    Atherton, C.S.

    1997-04-01

    Acetone may be an important source of reactive odd hydrogen in the upper troposphere and lower stratosphere. This source of odd hydrogen may affect the concentration of a number of species, including ozone, nitrogen oxides, methane, and others. Traditional, acetone had been considered a by-product of the photochemical oxidation of other species, and had not entered models as a primary emission. However, recent work estimates a global source term of 40-60 Tg acetone/year. Of this, 25% is directly emitted during biomass burning, and 20% is directly emitted by evergreens and other plants. Only 3% is due to anthropogenic/industrial emissions. The bulk of the remainder, 51% of the acetone source, is a secondary product from the oxidation of propane, isobutane, and isobutene. Also, while it is speculated that the oxidation of pinene (a biogenic emission) may also contribute about 6 Tg/year, this term is highly uncertain. Thus, the two largest primary sources of acetone are biogenic emission and biomass burning, with industrial/anthropogenic emissions very small in comparison.

  11. Sensor gas analyzer for acetone determination in expired air

    NASA Astrophysics Data System (ADS)

    Baranov, Vitaly V.

    2001-05-01

    Diseases and changes in the way of life change the concentration and composition of the expired air. Our adaptable gas analyzer is intended for the selective analysis of expired air and can be adapted for the solution of current diagnostic and analytical tasks by the user (a physician or a patient). Having analyzed the existing trends in the development of noninvasive diagnostics we have chosen the method of noninvasive acetone detection in expired air, where the acetone concentration correlates with blood and urine glucose concentrations. The appearance of acetone in expired air is indicative of disorders that may be caused not only by diabetes but also be wrong diet, incorrect sportsmen training etc. To control the disorders one should know the acetone concentration in the human body. This knowledge allows one to judge upon the state of the patient, choose a correct diet that will not cause damage to the patient's health, determine sportsmen training efficiency and results and solve the artificial pancreas problem. Our device provide highly accurate analysis, rapid diagnostics and authentic acetone quantification in the patient's body at any time aimed at prediction of the patient's state and assessing the efficiency of the therapy used. Clinical implementation of the device will improve the health and save lives of many thousands of diabetes sufferers.

  12. Nitrate-Dependent Degradation of Acetone by Alicycliphilus and Paracoccus Strains and Comparison of Acetone Carboxylase Enzymes ▿

    PubMed Central

    Dullius, Carlos Henrique; Chen, Ching-Yuan; Schink, Bernhard

    2011-01-01

    A novel acetone-degrading, nitrate-reducing bacterium, strain KN Bun08, was isolated from an enrichment culture with butanone and nitrate as the sole sources of carbon and energy. The cells were motile short rods, 0.5 to 1 by 1 to 2 μm in size, which gave Gram-positive staining results in the exponential growth phase and Gram-negative staining results in the stationary-growth phase. Based on 16S rRNA gene sequence analysis, the isolate was assigned to the genus Alicycliphilus. Besides butanone and acetone, the strain used numerous fatty acids as substrates. An ATP-dependent acetone-carboxylating enzyme was enriched from cell extracts of this bacterium and of Alicycliphilus denitrificans K601T by two subsequent DEAE Sepharose column procedures. For comparison, acetone carboxylases were enriched from two additional nitrate-reducing bacterial species, Paracoccus denitrificans and P. pantotrophus. The products of the carboxylase reaction were acetoacetate and AMP rather than ADP. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of cell extracts and of the various enzyme preparations revealed bands corresponding to molecular masses of 85, 78, and 20 kDa, suggesting similarities to the acetone carboxylase enzymes described in detail for the aerobic bacterium Xanthobacter autotrophicus strain Py2 (85.3, 78.3, and 19.6 kDa) and the phototrophic bacterium Rhodobacter capsulatus. Protein bands were excised and compared by mass spectrometry with those of acetone carboxylases of aerobic bacteria. The results document the finding that the nitrate-reducing bacteria studied here use acetone-carboxylating enzymes similar to those of aerobic and phototrophic bacteria. PMID:21841031

  13. Direct conversion of bio-ethanol to isobutene on nanosized Zn(x)Zr(y)O(z) mixed oxides with balanced acid-base sites.

    PubMed

    Sun, Junming; Zhu, Kake; Gao, Feng; Wang, Chongmin; Liu, Jun; Peden, Charles H F; Wang, Yong

    2011-07-27

    We report the design and synthesis of nanosized Zn(x)Zr(y)O(z) mixed oxides for direct and high-yield conversion of bio-ethanol to isobutene (~83%). ZnO is addded to ZrO(2) to selectively passivate zirconia's strong Lewis acidic sites and weaken Brönsted acidic sites, while simultaneously introducing basicity. As a result, the undesired reactions of bio-ethanol dehydration and acetone polymerization/coking are suppressed. Instead, a surface basic site-catalyzed ethanol dehydrogenation to acetaldehyde, acetaldehyde to acetone conversion via a complex pathway including aldol-condensation/dehydrogenation, and a Brönsted acidic site-catalyzed acetone-to-isobutene reaction pathway dominates on the nanosized Zn(x)Zr(y)O(z) mixed oxide catalyst, leading to a highly selective process for direct conversion of bio-ethanol to isobutene.

  14. Si:WO(3) Sensors for highly selective detection of acetone for easy diagnosis of diabetes by breath analysis.

    PubMed

    Righettoni, Marco; Tricoli, Antonio; Pratsinis, Sotiris E

    2010-05-01

    Acetone in the human breath is an important marker for noninvasive diagnosis of diabetes. Here, novel chemo-resistive detectors have been developed that allow rapid measurement of ultralow acetone concentrations (down to 20 ppb) with high signal-to-noise ratio in ideal (dry air) and realistic (up to 90% RH) conditions. The detector films consist of (highly sensitive) pure and Si-doped WO(3) nanoparticles (10-13 nm in diameter) made in the gas phase and directly deposited onto interdigitated electrodes. Their sensing properties (selectivity, limit of detection, response, and recovery times) have been investigated as a function of operating temperature (325-500 degrees C), relative humidity (RH), and interfering analyte (ethanol or water vapor) concentration. It was found that Si-doping increases and stabilizes the acetone-selective epsilon-WO(3) phase while increasing its thermal stability and, thus, results in superior sensing performance with an optimum at about 10 mol % Si content. Furthermore, increasing the operation temperature decreased the detector response to water vapor, and above 400 degrees C, it was (acetone) and diabetes patients (>or=1800 ppb) can be clearly distinguished by a remarkable gap (40%) in sensor response. As a result, these solid state detectors may offer a portable and cost-effective alternative to more bulky systems for noninvasive diabetes detection by human breath analysis.

  15. Acetone Powder From Dormant Seeds of Ricinus communis L

    NASA Astrophysics Data System (ADS)

    Cavalcanti, Elisa D. C.; Maciel, Fábio M.; Villeneuve, Pierre; Lago, Regina C. A.; Machado, Olga L. T.; Freire, Denise M. G.

    The influence of several factors on the hydrolytic activity of lipase, present in the acetone powder from dormant castor seeds (Ricinus communis) was evaluated. The enzyme showed a marked specificity for short-chain substrates. The best reaction conditions were an acid medium, Triton X-100 as the emulsifying agent and a temperature of 30°C. The lipase activity of the acetone powder of different castor oil genotypes showed great variability and storage stability of up to 90%. The toxicology analysis of the acetone powder from genotype Nordestina BRS 149 showed a higher ricin (toxic component) content, a lower 2S albumin (allergenic compound) content, and similar allergenic potential compared with untreated seeds.

  16. Detoxification of biomass derived acetate via metabolic conversion to ethanol, acetone, isopropanol, or ethyl acetate

    DOEpatents

    Sillers, William Ryan; Van Dijken, Hans; Licht, Steve; Shaw, IV, Arthur J.; Gilbert, Alan Benjamin; Argyros, Aaron; Froehlich, Allan C.; McBride, John E.; Xu, Haowen; Hogsett, David A.; Rajgarhia, Vineet B.

    2017-03-28

    One aspect of the invention relates to a genetically modified thermophilic or mesophilic microorganism, wherein a first native gene is partially, substantially, or completely deleted, silenced, inactivated, or down-regulated, which first native gene encodes a first native enzyme involved in the metabolic production of an organic acid or a salt thereof, thereby increasing the native ability of said thermophilic or mesophilic microorganism to produce lactate or acetate as a fermentation product. In certain embodiments, the aforementioned microorganism further comprises a first non-native gene, which first non-native gene encodes a first non-native enzyme involved in the metabolic production of lactate or acetate. Another aspect of the invention relates to a process for converting lignocellulosic biomass to lactate or acetate, comprising contacting lignocellulosic biomass with a genetically modified thermophilic or mesophilic microorganism.

  17. Distribution coefficients of alcohols in the air-butanol system

    SciTech Connect

    Filimonov, V.N.; Milyaev, Yu.F.; Balyatinskaya, L.N.

    1987-12-01

    The chromatographic analysis of mixtures of lower C/sub 1/-C/sub 3/ aliphatic alcohols was made; n-butanol was used as the absorbent. A Tsvet-100 chromatograph was used with a flame ionization detector, which was calibrated against standard solutions of alcohols in the n-butanol. Characteristics of the absorption concentration are shown. The liquid phase was analyzed for various concentrations of the substance being determined after bringing it into equilibrium with the gas phase. According to the limits of detection found experimentally, the gain in the increase in sensitivity in the analysis of alcohols having an equilibrium concentration compared with direct chromatographing comprises the values 1.1, 6.9, and 8.7.

  18. Fragrance material review on 2-ethyl-1-butanol.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2010-07-01

    A toxicologic and dermatologic review of 2-ethyl-1-butanol when used as a fragrance ingredient is presented. 2-Ethyl-1-butanol is a member of the fragrance structural group branched chain saturated alcohols. The common characteristic structural elements of the alcohols with saturated branched chain are one hydroxyl group per molecule, and a C(4)-C(12) carbon chain with one or several methyl side chains. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances.

  19. Extractions of isoquinoline alkaloids with butanol and octanol.

    PubMed

    Gregorová, Jana; Babica, Jan; Marek, Radek; Paulová, Hana; Táborská, Eva; Dostál, Jirí

    2010-09-01

    Six different isoquinoline alkaloids (sanguinarine, chelerythrine, berberine, coptisine, allocryptopine, and protopine) were extracted by butanol and octanol from aqueous solution, pH 4.5. The samples were analyzed by HPLC. Butanol extraction was non-selective, alkaloids passed into organic phase in 83-98%. Octanol extraction provided more selective yields: sanguinarine 99%, chelerythrine 94%, berberine 18%, coptisine 16%, allocryptopine 7.5%, protopine 7%. Further, we tested octanol treatment of extract from Dicranostigma lactucoides. The octanol extraction yields were also selective: sanguinarine 98%, chelerythrine 92%, chelirubine 92.5%, protopine 6% and allocryptopine 3.5%. 6-Butoxy-5,6-dihydrosanguinarine and 6-butoxy-5,6-dihydrochelerythrine were prepared and their NMR and MS data are reported and discussed.

  20. Recent advances to improve fermentative butanol production: genetic engineering and fermentation technology.

    PubMed

    Zheng, Jin; Tashiro, Yukihiro; Wang, Qunhui; Sonomoto, Kenji

    2015-01-01

    Butanol has recently attracted attention as an alternative biofuel because of its various advantages over other biofuels. Many researchers have focused on butanol fermentation with renewable and sustainable resources, especially lignocellulosic materials, which has provided significant progress in butanol fermentation. However, there are still some drawbacks in butanol fermentation in terms of low butanol concentration and productivity, high cost of feedstock and product inhibition, which makes butanol fermentation less competitive than the production of other biofuels. These hurdles are being resolved in several ways. Genetic engineering is now available for improving butanol yield and butanol ratio through overexpression, knock out/down, and insertion of genes encoding key enzymes in the metabolic pathway of butanol fermentation. In addition, there are also many strategies to improve fermentation technology, such as multi-stage continuous fermentation, continuous fermentation integrated with immobilization and cell recycling, and the inclusion of additional organic acids or electron carriers to change metabolic flux. This review focuses on the most recent advances in butanol fermentation especially from the perspectives of genetic engineering and fermentation technology.

  1. Isolation and characterisation of non-anaerobic butanol-producing symbiotic system TSH06.

    PubMed

    Wang, Genyu; Wu, Pengfei; Liu, Ya; Mi, Shuo; Mai, Shuai; Gu, Chunkai; Wang, Gehua; Liu, Hongjuan; Zhang, Jianan; Børresen, Børre Tore; Mellemsæther, Evy; Kotlar, Hans Kristian

    2015-10-01

    Butanol-producing microorganisms are all obligate anaerobes. In this study, a unique symbiotic system TSH06 was isolated to be capable of producing butanol under non-anaerobic condition. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S ribosomal RNA (rRNA) revealed that two strains coexist in TSH06. The two strains were identical to Clostridium acetobutylicum and Bacillus cereus, respectively. They were isolated individually and named as C. acetobutylicum TSH1 and B. cereus TSH2. C. acetobutylicum TSH1 is a butanol-producing, obligate anaerobic strain. Facultative anaerobic B. cereus TSH2 did not possess the ability of butanol production; however, it offered C. acetobutylicum TSH1 the viability under non-anaerobic condition. Moreover, B. cereus TSH2 enhanced butanol yield and speed of fermentation. TSH06 produced 12.97 g/L butanol and 15.39 g/L total solvent under non-anaerobic condition, which is 25 and 24 %, respectively, higher than those of C. acetobutylicum TSH1. In addition, TSH06 produced butanol faster under non-anaerobic condition than under anaerobic condition. Butanol accounted for more than 80 % of total solvent, which is higher than the known report. TSH06 was stable during passage. In all, TSH06 is a promising candidate for industrialisation of biobutanol with high yield, high butanol proportion, easy-handling and time-saving system. These results demonstrated the potential advantage of symbiosis. This study also provides a promising strategy for butanol fermentation.

  2. Vapor pressures of binary mixtures of hexane + 1-butanol, + 2-butanol, + 2-methyl-1-propanol, or + 2-methyl-2-propanol at 298. 15 K

    SciTech Connect

    Rodriguez, V.; Pardo, J.; Lopez, M.C.; Royo, F.M.; Urieta, J.S. . Dept. de Quimica Organica-Quimica Fisica)

    1993-07-01

    Previous papers from this laboratory reported measurements of excess enthalpies, excess volumes, vapor pressures, and dipole moments for mixtures containing an alkanol. The authors have now begun a systematic study of the properties of mixtures containing isomeric butanols. While many studies of the thermodynamic properties of 1-butanol have been published, only a few systematic investigations have been carried out for mixtures containing isomeric butanols. The total vapor pressures of binary mixtures of hexane + 1-butanol, + 2-butanol, + 2-methyl-1-propanol, or + 2-methyl-2-propanol were measured by a static method at 298.15 K. Vapor-phase compositions, activity coefficients, and excess molar Gibbs energies were calculated by Barker's method.

  3. Comprehensive reaction mechanism for n-butanol pyrolysis and combustion

    SciTech Connect

    Harper, Michael R.; Green, William H.; Geem, Kevin M. van; Pyl, Steven P.; Marin, Guy B.

    2011-01-15

    A detailed reaction mechanism for n-butanol, consisting of 263 species and 3381 reactions, has been generated using the open-source software package, Reaction Mechanism Generator (RMG). The mechanism is tested against recently published data - jet-stirred reactor mole fraction profiles, opposed-flow diffusion flame mole fraction profiles, autoignition delay times, and doped methane diffusion flame mole fraction profiles - and newly acquired n-butanol pyrolysis experiments with very encouraging results. The chemistry of butanal is also validated against autoignition delay times obtained in shock tube experiments. A flux and sensitivity analysis for each simulated dataset is discussed and reveals important reactions where more accurate rate constant estimates were required. New rate constant expressions were computed using quantum chemistry and transition state theory calculations. Furthermore, in addition to comparing the proposed model with the eight datasets, the model is also compared with recently published n-butanol models for three of the datasets. Key differences between the proposed model and the published models are discussed. (author)

  4. ATP drives direct photosynthetic production of 1-butanol in cyanobacteria.

    PubMed

    Lan, Ethan I; Liao, James C

    2012-04-17

    While conservation of ATP is often a desirable trait for microbial production of chemicals, we demonstrate that additional consumption of ATP may be beneficial to drive product formation in a nonnatural pathway. Although production of 1-butanol by the fermentative coenzyme A (CoA)-dependent pathway using the reversal of β-oxidation exists in nature and has been demonstrated in various organisms, the first step of the pathway, condensation of two molecules of acetyl-CoA to acetoacetyl-CoA, is thermodynamically unfavorable. Here, we show that artificially engineered ATP consumption through a pathway modification can drive this reaction forward and enables for the first time the direct photosynthetic production of 1-butanol from cyanobacteria Synechococcus elongatus PCC 7942. We further demonstrated that substitution of bifunctional aldehyde/alcohol dehydrogenase (AdhE2) with separate butyraldehyde dehydrogenase (Bldh) and NADPH-dependent alcohol dehydrogenase (YqhD) increased 1-butanol production by 4-fold. These results demonstrated the importance of ATP and cofactor driving forces as a design principle to alter metabolic flux.

  5. IRIS Toxicological Review of n-Butanol (Interagency Science ...

    EPA Pesticide Factsheets

    On September 8, 2011, the Toxicological Review of n-Butanol (External Review Draft) was released for external peer review and public comment. The Toxicological Review and charge were reviewed internally by EPA and by other federal agencies and White House Offices before public release. In the new IRIS process, introduced by the EPA Administrator, all written comments on IRIS assessments submitted by other federal agencies and White House Offices will be made publicly available. Accordingly, interagency comments with EPA's response and the interagency science consultation draft of the IRIS Toxicological Review of n-Butanol and the charge to external peer reviewers are posted on this site. EPA is undertaking an Integrated Risk Information System (IRIS) health assessment for n-butanol. IRIS is an EPA database containing Agency scientific positions on potential adverse human health effects that may result from chronic (or lifetime) exposure to chemicals in the environment. IRIS contains chemical-specific summaries of qualitative and quantitative health information in support of two steps of the risk assessment paradigm, i.e., hazard identification and dose-response evaluation. IRIS assessments are used in combination with specific situational exposure assessment information to evaluate potential public health risk associated with environmental contaminants.

  6. Value of furfural/ethanol coproduction from acid hydrolysis processes

    SciTech Connect

    Parker, S.; Calnon, M.; Feinberg, D.; Power, A.; Weiss, L.

    1983-08-01

    The benefits of two modifications in the acid hydrolysis of cellulosic feedstocks for the production of ethanol fuels were investigated: marketing of the by-product furfural and xylose fermentation. Preliminary analysis indicate that the furfural by-product furfural and xylose fermentation. Perliminary analyses indicate that the furfural by-product credit is more beneficial at a minimum net profit of $0.08/lb of furfural. For this credit to have a major impact on ethanol production costs, new markets for large quantities of furfural must be identified. Furfural can be an alternative feedstock for hydrocarbon-based commodity chemicals. The costs and profitabilities of producing five chemicals from furfurals as opposed to conventional hydrocarbon-based feedstocks were studied. The furfural processes for production of styrene and butadiene were found to be marginally competitive or not competitive. The furfural processes for adipic acid, maleic anhydride, and butanol could be competitive. Results of analysis by a computer model of the petrochemical industry indicate that with furfural markets additional to these three furfural processes, over 2.5 x 10/sup 9/ gal of ethanol could be marketed at about $1.00/gal. Converting the xylose stream to ethanol has about the same effect on the selling price of ethanol as the furfural credit. The greatest ethanol production will result from xylose fermentation, but the furfural credit offers large near-term profits and has a more diversified impact on reducing petroleum product demand. 6 figures, 17 tables.

  7. NASOPHARYNGEAL CONCENTRATIONS IN THE HUMAN VOLUNTEER BREATHING ACETONE

    EPA Science Inventory

    In an effort to examine the absorption of a common chemical into the nasopharyngeal region in humans, a 57 year old male volunteer inhaled uniformly labeled 13C-acetone at 1.4 ppm for 30 min while performing different breathing maneuvers; nose inhale, nose exhale (NINE); mouth ...

  8. Controlling tunnelling in methane loss from acetone ions by deuteration.

    PubMed

    Bodi, Andras; Baer, Tomas; Wells, Nancy K; Fakhoury, Daniel; Klecyngier, David; Kercher, James P

    2015-11-21

    Energetic acetone cations decay by methane or methyl radical loss. Although the methane-loss barrier to form the ketene cation is higher and the activation entropy is lower, it has a significant branching ratio at low energies thanks to quantum tunnelling. H-atom tunnelling can be selectively quenched and the methane-loss channel suppressed quantitatively by deuteration.

  9. Accurate Assignment of Ethanol Origin in Postmortem Urine: A Case Study

    DTIC Science & Technology

    2004-08-01

    indole-3- acetaldehyde (5-HIAL). This intermediate can undergo either oxidation or reduction, as shown in Figure 1. Oxidation of the aldehyde...other VOCs, including n-propanol, n-butanol, and acetaldehyde at substantial concentrations. These other VOCs, like ethanol, were present in each...hyde, which was present at 12 mg/dL in the blood. This concentration of acetaldehyde result could reasonably be considered to support either antemortem

  10. A fully integrated standalone portable cavity ringdown breath acetone analyzer

    NASA Astrophysics Data System (ADS)

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  11. Understanding butanol tolerance and assimilation in Pseudomonas putida BIRD-1: an integrated omics approach.

    PubMed

    Cuenca, María del Sol; Roca, Amalia; Molina-Santiago, Carlos; Duque, Estrella; Armengaud, Jean; Gómez-Garcia, María R; Ramos, Juan L

    2016-01-01

    Pseudomonas putida BIRD-1 has the potential to be used for the industrial production of butanol due to its solvent tolerance and ability to metabolize low-cost compounds. However, the strain has two major limitations: it assimilates butanol as sole carbon source and butanol concentrations above 1% (v/v) are toxic. With the aim of facilitating BIRD-1 strain design for industrial use, a genome-wide mini-Tn5 transposon mutant library was screened for clones exhibiting increased butanol sensitivity or deficiency in butanol assimilation. Twenty-one mutants were selected that were affected in one or both of the processes. These mutants exhibited insertions in various genes, including those involved in the TCA cycle, fatty acid metabolism, transcription, cofactor synthesis and membrane integrity. An omics-based analysis revealed key genes involved in the butanol response. Transcriptomic and proteomic studies were carried out to compare short and long-term tolerance and assimilation traits. Pseudomonas putida initiates various butanol assimilation pathways via alcohol and aldehyde dehydrogenases that channel the compound to central metabolism through the glyoxylate shunt pathway. Accordingly, isocitrate lyase - a key enzyme of the pathway - was the most abundant protein when butanol was used as the sole carbon source. Upregulation of two genes encoding proteins PPUBIRD1_2240 and PPUBIRD1_2241 (acyl-CoA dehydrogenase and acyl-CoA synthetase respectively) linked butanol assimilation with acyl-CoA metabolism. Butanol tolerance was found to be primarily linked to classic solvent defense mechanisms, such as efflux pumps, membrane modifications and control of redox state. Our results also highlight the intensive energy requirements for butanol production and tolerance; thus, enhancing TCA cycle operation may represent a promising strategy for enhanced butanol production.

  12. Production of butanol by fermentation in the presence of cocultures of clostridium

    NASA Technical Reports Server (NTRS)

    Bergstrom, S. L.; Foutch, G. L. (Inventor)

    1985-01-01

    Sugars are converted to a mixture of solvents including butanol by a fermentation process employing a coculture of microorganisms of the Clostridium genus, one of said microorganisms favoring the production of butyric acid and the other of which converts the butyric acid so produced to butanol. The use of a coculture substantially increases the yield of butanol over that obtained using a culture employing only one microorganism.

  13. In vitro antioxidant activity and inhibitory effect, on oleic acid-induced hepatic steatosis, of fractions and subfractions from oat (Avena sativa L.) ethanol extract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oats (Avena sativa L.) were extracted with 80% aqueous ethanol and the extract was successively isolated by liquid-liquid partition to yield n-hexane, ethyl acetate, n-butanol and water layers. Among these extractions the ethyl acetate (EA) layer exhibited the highest total phenolic content (TPC), t...

  14. IRIS Toxicological Review of Tert-Butyl Alcohol (Tert-Butanol) ...

    EPA Pesticide Factsheets

    The IRIS Toxicological Review of tert-Butyl Alcohol (tert-Butanol) was released for external peer review in April 2017. EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis supporting the tert-butanol assessment and release a final report of their review. Information regarding the peer review can be found on the SAB website. EPA is conducting an Integrated Risk Information System (IRIS) health assessment for tert-butanol. The outcome of this project is a Toxicological Review and IRIS Summary for tert-butanol that will be entered into the IRIS database.

  15. Genomic Library Screens for Genes Involved in n-Butanol Tolerance in Escherichia coli

    PubMed Central

    Reyes, Luis H.; Almario, Maria P.; Kao, Katy C.

    2011-01-01

    Background n-Butanol is a promising emerging biofuel, and recent metabolic engineering efforts have demonstrated the use of several microbial hosts for its production. However, most organisms have very low tolerance to n-butanol (up to 2% (v/v)), limiting the economic viability of this biofuel. The rational engineering of more robust n-butanol production hosts relies upon understanding the mechanisms involved in tolerance. However, the existing knowledge of genes involved in n-butanol tolerance is limited. The goal of this study is therefore to identify E. coli genes that are involved in n-butanol tolerance. Methodology/Principal Findings Using a genomic library enrichment strategy, we identified approximately 270 genes that were enriched or depleted in n-butanol challenge. The effects of these candidate genes on n-butanol tolerance were experimentally determined using overexpression or deletion libraries. Among the 55 enriched genes tested, 11 were experimentally shown to confer enhanced tolerance to n-butanol when overexpressed compared to the wild-type. Among the 84 depleted genes tested, three conferred increased n-butanol resistance when deleted. The overexpressed genes that conferred the largest increase in n-butanol tolerance were related to iron transport and metabolism, entC and feoA, which increased the n-butanol tolerance by 32.8±4.0% and 49.1±3.3%, respectively. The deleted gene that resulted in the largest increase in resistance to n-butanol was astE, which enhanced n-butanol tolerance by 48.7±6.3%. Conclusions/Significance We identified and experimentally verified 14 genes that decreased the inhibitory effect of n-butanol tolerance on E. coli. From the data, we were able to expand the current knowledge on the genes involved in n-butanol tolerance; the results suggest that an increased iron transport and metabolism and decreased acid resistance may enhance n-butanol tolerance. The genes and mechanisms identified in this study will be helpful in the

  16. Homeoviscous response of Clostridium pasteurianum to butanol toxicity during glycerol fermentation.

    PubMed

    Venkataramanan, Keerthi P; Kurniawan, Yogi; Boatman, Judy J; Haynes, Cassandra H; Taconi, Katherine A; Martin, Lenore; Bothun, Geoffrey D; Scholz, Carmen

    2014-06-10

    Clostridium pasteurianum ATCC 6013 achieves high n-butanol production when glycerol is used as the sole carbon source. In this study, the homeoviscous membrane response of C. pasteurianum ATCC 6013 has been examined through n-butanol challenge experiments. Homeoviscous response is a critical aspect of n-butanol tolerance and has not been examined in detail for C. pasteurianum. Lipid membrane compositions were examined for glycerol fermentations with n-butanol production, and during cell growth in the absence of n-butanol production, using gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance ((1)H-NMR). Membrane stabilization due to homeoviscous response was further examined by surface pressure-area (π-A) analysis of membrane extract monolayers. C. pasteurianum was found to exert a homeoviscous response that was comprised of an increase lipid tail length and a decrease in the percentage of unsaturated fatty acids with increasing n-butanol challenge. This led to a more rigid or stable membrane that counteracted n-butanol fluidization. This is the first report on the changes in the membrane lipid composition during n-butanol production by C. pasteurianum ATCC 6013, which is a versatile microorganism that has the potential to be engineered as an industrial n-butanol producer using crude glycerol.

  17. Measurement of the diffusion coefficient of acetone in succinonitrile at its melting point

    NASA Technical Reports Server (NTRS)

    Chopra, M. A.; Glicksman, M. E.; Singh, N. B.

    1988-01-01

    The diffusion coefficient of acetone in liquid succinonitrile at 331.1 K was determined using the method of McBain and Dawson (1935). Only dilute mixtures of SCN-acetone were studied. The interdiffusion constant was determined to be 0.0000127 sq cm/s and was essentially independent of the acetone concentration over the range investigated (0.5 to 18 mol pct acetone).

  18. Effect of Water on Ethanol Conversion over ZnO

    SciTech Connect

    Rahman, Muhammad Mahfuzur; Davidson, Stephen D.; Sun, Junming; Wang, Yong

    2015-10-01

    This work focuses on understanding the role of water on ethanol conversion over zinc oxide (ZnO). It was found that a competitive adsorption between ethanol and water occurs on ZnO, which leads to the blockage of the strong Lewis acid site by water on ZnO. As a result, both dehydration and dehydrogenation reactions are inhibited. However, the extent of inhibition for dehydration is orders of magnitude higher than that for dehydrogenation, leading to the shift of reaction pathway from ethanol dehydration to dehydrogenation. In the secondary reactions for acetaldehyde conversion, water inhibits the acetaldehyde aldol-condensation to crotonaldehyde, favoring the oxidation of acetaldehyde to acetic acid, and then to acetone via ketonization at high temperature (i.e., 400 °C).

  19. Evaluation of unbound free heme in plant cells by differential acetone extraction.

    PubMed

    Espinas, Nino A; Kobayashi, Koichi; Takahashi, Shigekazu; Mochizuki, Nobuyoshi; Masuda, Tatsuru

    2012-07-01

    Heme functions not only as a prosthetic group of hemoproteins but also as a regulatory molecule, suggesting the presence of 'free' heme. Classically, total non-covalently bound heme is extracted from plant samples with acidic acetone after removal of pigments with basic and neutral acetone. Earlier work proposed that free heme can be selectively extracted into basic acetone. Using authentic hemoproteins, we confirmed that acidic acetone can quantitatively extract heme, while no heme was extracted into neutral acetone. Meanwhile, a certain amount of heme was extracted into basic acetone from hemoglobin and myoglobin. Moreover, basic acetone extracted loosely bound heme from bovine serum albumin, implying that the nature of hemoproteins largely influences heme extraction into basic acetone. Using a highly sensitive heme assay, we found that basic and neutral acetone can extract low levels of heme from plant samples. In addition, neutral acetone quantitatively extracted free heme when it was externally added to plant homogenates. Furthermore, the level of neutral acetone-extractable heme remained unchanged by precursor (5-aminolevulinic acid) feeding, while increased by norflurazon treatment which abolishes chloroplast biogenesis. However, changes in these heme levels did not correlate to genomes uncoupled phenotypes, suggesting that the level of unbound free heme would not affect retrograde signaling from plastids to the nucleus. The present data demonstrate that the combination of single-step acetone extraction following a sensitive heme assay is the ideal method for determining total and free heme in plants.

  20. Laminar burning velocities and flame instabilities of butanol isomers-air mixtures

    SciTech Connect

    Gu, Xiaolei; Huang, Zuohua; Wu, Si; Li, Qianqian

    2010-12-15

    Laminar burning velocities and flame instabilities of the butanol-air premixed flames and its isomers are investigated using the spherically expanding flame with central ignition at initial temperature of 428 K and initial pressures of 0.10 MPa, 0.25 MPa, 0.50 MPa and 0.75 MPa. Laminar burning velocities and sensitivity factor of n-butanol-air mixtures are computed using a newly developed kinetic mechanism. Unstretched laminar burning velocity, adiabatic temperature, Lewis number, Markstein length, critical flame radius and Peclet number are obtained over a wide range of equivalence ratios. Effect of molecular structure on laminar burning velocity of the isomers of butanol is analyzed from the aspect of C-H bond dissociation energy. Study indicates that although adiabatic flame temperatures of the isomers of butanol are the same, laminar burning velocities give an obvious difference among the isomers of butanol. This indicates that molecular structure has a large influence on laminar burning velocities of the isomers of butanol. Branching (-CH3) will decrease laminar burning velocity. Hydroxyl functional group (-OH) attaching to the terminal carbon atoms gives higher laminar burning velocity compared to that attaching to the inner carbon atoms. Calculated dissociation bond energies show that terminal C-H bonds have larger bond energies than that of inner C-H bonds. n-Butanol, no branching and with hydroxyl functional group (-OH) attaching to the terminal carbon atom, gives the largest laminar burning velocity. tert-Butanol, with highly branching and hydroxyl functional group (-OH) attaching to the inner carbon atom, gives the lowest laminar burning velocity. Laminar burning velocities of iso-butanol and sec-butanol are between those of n-butanol and tert-butanol. The instant of transition to cellularity is experimentally determined for the isomers of butanol and subsequently interpreted on the basis of hydrodynamic and diffusion-thermal instabilities. Little effect

  1. Positronium lifetime in supercooled 1-butanol: Search for polyamorphism

    NASA Astrophysics Data System (ADS)

    Zgardzińska, B.; Paluch, M.; Goworek, T.

    2010-05-01

    Isothermal transformations of supercooled 1-butanol were observed by positron lifetime spectroscopy. Transformation rate is the highest near 150 K, whereas below 140 K it slows down becoming undetectable below 120 K. At the temperature range of 123-135 K the ortho-positronium lifetime achieves the final value which is higher than the one observed for crystalline phase. This is an indication of transition to a new (meta)stable structure, in which the ortho-positronium lifetime and intensity reach values that are intermediate between liquid and crystal phases. Consistency of positron annihilation data with the concept of two coexisting phases is discussed.

  2. Enhanced Acetone Sensing Characteristics of ZnO/Graphene Composites.

    PubMed

    Zhang, Hao; Cen, Yuan; Du, Yu; Ruan, Shuangchen

    2016-11-09

    ZnO/graphene (ZnO-G) hybrid composites are prepared via hydrothermal synthesis with graphite, N-methyl-pyrrolidone (NMP), and Zn(NO₃)₂·6H₂O as the precursors. The characterizations, including X-ray diffraction (XRD), thermogravimetric analyses (TGA), Raman spectroscopy, and transmission electron microscopy (TEM) indicate the formation of ZnO-G. Gas sensors were fabricated with ZnO-G composites and ZnO as sensing material, indicating that the response of the ZnO towards acetone was significantly enhanced by graphene doping. It was found that the ZnO-G sensor exhibits remarkably enhanced response of 13.3 at the optimal operating temperature of 280 °C to 100 ppm acetone, an improvement from 7.7 with pure ZnO.

  3. Enhanced Acetone Sensing Characteristics of ZnO/Graphene Composites

    PubMed Central

    Zhang, Hao; Cen, Yuan; Du, Yu; Ruan, Shuangchen

    2016-01-01

    ZnO/graphene (ZnO-G) hybrid composites are prepared via hydrothermal synthesis with graphite, N-methyl-pyrrolidone (NMP), and Zn(NO3)2·6H2O as the precursors. The characterizations, including X-ray diffraction (XRD), thermogravimetric analyses (TGA), Raman spectroscopy, and transmission electron microscopy (TEM) indicate the formation of ZnO-G. Gas sensors were fabricated with ZnO-G composites and ZnO as sensing material, indicating that the response of the ZnO towards acetone was significantly enhanced by graphene doping. It was found that the ZnO-G sensor exhibits remarkably enhanced response of 13.3 at the optimal operating temperature of 280 °C to 100 ppm acetone, an improvement from 7.7 with pure ZnO. PMID:27834870

  4. Cellulosic Substrates and Challenges Ahead

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cost of production of butanol (acetone-butanol-ethanol; or ABE) is determined by feedstock prices, fermentation, recovery, by-product credits and the waste water treatment. Along these lines, we have an intensive research program on the use of various agricultural substrates, fermentation strate...

  5. Effect of Coadsorbed Water on the Photodecomposition of Acetone on TiO2(110)

    SciTech Connect

    Henderson, Michael A.

    2008-06-10

    The influence of coadsorbed water on the photodecomposition of acetone on TiO2 was examined using temperature programmed desorption (TPD) and the rutile TiO2(110) surface as a model photocatalyst. Of the two major influences ascribed to water in the heterogeneous photocatalysis literature (promotion via OH radical supply and inhibition due to site blocking), only the negative influence of water was observed. As long as the total water and acetone coverage was maintained well below the first layer saturation coverage (‘1 ML’), little inhibition of acetone photodecomposition was observed. However, as the total water+acetone coverage exceeded 1 ML, acetone was preferentially displaced from the first layer to physisorbed states by water and the extent of acetone photodecomposition attenuated. The displacement originated from water compressing acetone into high coverage regions where increased acetone-acetone repulsions caused displacement from the first layer. The immediate product of acetone photodecomposition was adsorbed acetate, which occupies twice as many surface sites per molecule as compared to acetone. Since the acetate intermediate was more stable on the TiO2(110) surface than either water or acetone (as gauged by TPD) and since its photodecomposition rate was less than that of acetone, additional surface sites were not opened up during acetone photodecomposition for previously displaced acetone molecules to re-enter the first layer. Results in this study suggest that increased molecular-level repulsions between organic molecules brought about by increased water coverage are as influential in the inhibiting effect of water on photooxidation rates as are water-organic repulsions.

  6. Self-Associating Behavior of Acetone in Liquid Krypton.

    PubMed

    De Beuckeleer, Liene I; Herrebout, Wouter A

    2016-02-18

    Acetone molecules are inclined to self-associate through dipole-dipole interactions because of their large dipole moment. Infrared spectroscopy of compounds dissolved in liquid noble gases supported by high level ab initio calculations allows investigating the self-associating behavior and determining the thermodynamical properties. In this study, infrared spectra of various concentrations of acetone dissolved in liquid krypton are recorded at constant temperature. Overlapping monomer and dimer spectra are separated by analyzing the obtained data sets with numerical methods based on least-squares fitting. Although acetone is known to self-associate, only a few spectral features have been presented in literature before. In this study, the application of new numerical approaches succeeds in resolving overlapping spectra and allows observing isolated acetone dimer absorption bands for the complete mid infrared spectrum. By use of data sets of spectra recorded at temperatures between 134 and 142 K, the experimental standard dimerization enthalpy was determined to be -10.8 kJ mol(-1). MP2/aug-cc-pVDZ calculations predicted a stacked and planar dimer geometry of which the stacked geometry is more stable. Combining MP2 energies and single point corrections involving CCSD(T) calculations and complete basis set extrapolations based on the MP2/aug-cc-pVDZ equilibrium geometry lead to complexation energy of -28.4 kJ mol(-1) for the stacked geometry and -15.1 kJ mol(-1) for the planar geometry. The corresponding values for the complexation enthalpies in solution, obtained by combining these values with corrections for thermal and solvent influences are -13.7 and -5.8 kJ mol(-1).

  7. Cellulosic butanol production from agricultural biomass and residues: Recent advances in technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter details the recent advances made on bioconversion of lignocellulosic biomass to butanol, a superior biofuel that can be used in internal combustion engines or transportation industry. It should be noted that butanol producing cultures cannot tolerate or produce more than 20-30 g/L of ac...

  8. Biooxidation of n-butane to 1-butanol by engineered P450 monooxygenase under increased pressure.

    PubMed

    Nebel, Bernd A; Scheps, Daniel; Honda Malca, Sumire; Nestl, Bettina M; Breuer, Michael; Wagner, Hans-Günter; Breitscheidel, Boris; Kratz, Detlef; Hauer, Bernhard

    2014-12-10

    In addition to the traditional 1-butanol production by hydroformylation of gaseous propene and by fermentation of biomass, the cytochrome P450-catalyzed direct terminal oxidation of n-butane into the primary alcohol 1-butanol constitutes an alternative route to provide the high demand of this basic chemical. Moreover the use of n-butane offers an unexploited ubiquitous feed stock available in large quantities. Based on protein engineering of CYP153A from Polaromonas sp. JS666 and the improvement of the native redox system, a highly ω-regioselective (>96%) fusion protein variant (CYP153AP.sp.(G254A)-CPRBM3) for the conversion of n-butane into 1-butanol was developed. Maximum yield of 3.12g/L butanol, of which 2.99g/L comprise for 1-butanol, has been obtained after 20h reaction time. Due to the poor solubility of n-butane in an aqueous system, a high pressure reaction assembly was applied to increase the conversion. After optimization a maximum product content of 4.35g/L 1-butanol from a total amount of 4.53g/L butanol catalyzed by the self-sufficient fusion monooxygenase has been obtained at 15bar pressure. In comparison to the CYP153A wild type the 1-butanol concentration was enhanced fivefold using the engineered monooxygenase whole cell system by using the high-pressure reaction assembly.

  9. Improvement of 2,4-dinitrophenylhydrazine derivatization method for carbon isotope analysis of atmospheric acetone.

    PubMed

    Wen, Sheng; Yu, Yingxin; Guo, Songjun; Feng, Yanli; Sheng, Guoying; Wang, Xinming; Bi, Xinhui; Fu, Jiamo; Jia, Wanglu

    2006-01-01

    Through simulation experiments of atmospheric sampling, a method via 2,4-dinitrophenylhydrazine (DNPH) derivatization was developed to measure the carbon isotopic composition of atmospheric acetone. Using acetone and a DNPH reagent of known carbon isotopic compositions, the simulation experiments were performed to show that no carbon isotope fractionation occurred during the processes: the differences between the predicted and measured data of acetone-DNPH derivatives were all less than 0.5 per thousand. The results permitted the calculation of the carbon isotopic compositions of atmospheric acetone using a mass balance equation. In this method, the atmospheric acetone was collected by a DNPH-coated silica cartridge, washed out as acetone-DNPH derivatives, and then analyzed by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). Using this method, the first available delta13C data of atmospheric acetone are presented.

  10. Changes in membrane fatty acid composition through proton-induced fabF mutation enhancing 1-butanol tolerance in E. coli

    NASA Astrophysics Data System (ADS)

    Jeong, Haeyoung; Kim, Sun Hong; Han, Sang Soo; Kim, Myung Hee; Lee, Keun Chul

    2012-07-01

    While a rational approach based on genomic data has become the preferred method for microbial strain development, radiation-induced random mutagenesis is still a robust method for organisms such as plants whose genome or target gene information is unavailable. We previously reported on a combined approach that consists of proton irradiation and a long-term experimental evolution to enhance 1-butanol tolerance of the E. coli C strain so that it can be used as a basal strain for the production of 1-butanol, a potential biofuel along with ethanol. Genome sequencing of one randomly chosen clone (PKH5000) from the endpoint population revealed eleven mutations occurring in the coding regions, and we found that a mutation (F74C) in fabF gene encoding β-ketoacyl-ACP synthases II is associated with a twofold increase in the major unsaturated fatty acid, cis-vaccenic acid. The increase of cis-vaccenic acid by wild-type FabF, which is more active at low temperatures or in the presence of organic compounds, is considered to be a protective mechanism against cold stress. A structural analysis of the FabF protein suggests that the F74C mutation may affect the enzyme activity through a change in flexibility around the catalytic site. The expression of a plasmid that harbors mutant fabF gene in the fabF knockout strain enhanced growth in a medium containing butanol with a concomitant elevation of the cis-vaccenic acid level. Among the eight available Keio knockout strains for genes that have amino acid substitution in the PKH5000 strain, the fabF mutant showed the slowest growth in the presence of 0.7% butanol. We propose that fabF, as probably the gene most responsible for butanol tolerance in wild-type form, contributes further when converted into a F74C missense mutation, which is beneficial as it increases the level of cis-vaccenic acid.

  11. Acetone and Acetaldehyde Exchange Above a Managed Temperate Mountain Grassland

    NASA Astrophysics Data System (ADS)

    Hörtnagl, L. J.; Bamberger, I.; Graus, M.; Ruuskanen, T.; Schnitzhofer, R.; Hansel, A.; Wohlfahrt, G.

    2011-12-01

    The exchange of acetone and acetaldehyde was measured above an intensively managed hay meadow in the Stubai Valley (Tyrol, Austria) during the growing seasons in 2008 and 2009. Half-hourly fluxes of both compounds were calculated by means of the virtual disjunct eddy covariance (vDEC) method by combining the 3-dimensional wind data from a sonic anemometer with the compound specific volume mixing ratios quantified with a proton-transfer-reaction mass spectrometer (PTR-MS). The cutting of the meadow resulted in the largest perturbation of the VOC exchange rates. Peak emissions for both VOC species were observed during and right after the cutting of the meadow, with rates of up to 12.1 and 10.1 nmol m-2 s-1 for acetaldehyde and acetone, respectively, reflecting the drying of the wounded plant material. During certain time periods, undisturbed by management events, both compounds exhibited a clear diurnal cycle. Emission rates of up to 3.7 nmol m-2 s-1 for acetaldehyde and 3.2 nmol m-2 s-1 for acetone were measured in October 2008, while a uptake of both compounds with rates of up to 1.8 and 2.1 nmol m-2 s-1, respectively, could be observed in May 2009, when also clear compensation points of 0.3 ppb for acetaldehyde and 1.0 ppb for acetone were observed. In an effort to explore the controls on observed exchange patterns, a simple and multiple linear regression analysis was conducted. A clear interconnection between VOC concentrations and VOC exchange could be seen only in May 2009, when concentration values alone explained 30.6% and 11.7% of the acetaldehyde and acetone flux variance, respectively. However, when trying to predict the observed exchange patterns of both VOC species in a multiple linear regression based on supporting environmental measurements - including air and soil temperature, soil water content and PAR among others - the analysis yielded unsatisfactory results, accounting for 10% and 4% of the observed acetaldehyde and acetone flux variance over both

  12. Kansas Ethanol Lyons Approval

    EPA Pesticide Factsheets

    This update August 9, 2016 letter from EPA approves, with modifications, the petition from Kansas Ethanol, LLC, Lyons facility, regarding non-grandfathered ethanol produced through a dry mill process, qualifying under the Clean Air Act for renewable fuel

  13. Emissions of aldehydes and ketones from a two-stroke engine using ethanol and ethanol-blended gasoline as fuel.

    PubMed

    Magnusson, Roger; Nilsson, Calle; Andersson, Barbro

    2002-04-15

    Besides aliphatic gasoline, ethanol-blended gasoline intended for use in small utility engines was recently introduced on the Swedish market. For small utility engines, little data is available showing the effects of these fuels on exhaust emissions, especially concerning aldehydes and ketones (carbonyls). The objective of the present investigation was to study carbonyl emissions and regulated emissions from a two-stroke chain saw engine using ethanol, gasoline, and ethanol-blended gasoline as fuel (0%, 15%, 50%, 85%, and 100% ethanol). The effects of the ethanol-blending level and mechanical changes of the relative air/fuel ratio, lambda, on exhaust emissions was investigated, both for aliphatic and regular gasoline. Formaldehyde, acetaldehyde, and aromatic aldehydes were the most abundant carbonyls in the exhaust. Acetaldehyde dominated for all ethanol-blended fuels (1.2-12 g/kWh, depending on the fuel and lambda), and formaldehyde dominated for gasoline (0.74-2.3 g/kWh, depending on the type of gasoline and lambda). The main effects of ethanol blending were increased acetaldehyde emissions (30-44 times for pure ethanol), reduced emissions of all other carbonyls exceptformaldehyde and acrolein (which showed a more complex relation to the ethanol content), reduced carbon monoxide (CO) and ntirogen oxide (NO) emissions, and increased hydrocarbon (HC) and nitrogen dixodie (NO2) emissions. The main effects of increasing lambda were increased emissions of carbonyls and nitrogen oxides (NOx) and reduced CO and HC emissions. When the two types of gasoline are considered, benzaldehyde and tolualdehyde could be directly related to the gasoline content of aromatics or olefins, but also acrolein, propanal, crotonaldehyde, and methyl ethyl ketone mainly originated from aromatics or olefins, while the main source for formaldehyde, acetaldehyde, acetone, methacrolein, and butanal was saturated aliphatic hydrocarbons.

  14. Integrated OMICS guided engineering of biofuel butanol-tolerance in photosynthetic Synechocystis sp. PCC 6803

    PubMed Central

    2013-01-01

    Background Photosynthetic cyanobacteria have been recently proposed as a ‘microbial factory’ to produce butanol due to their capability to utilize solar energy and CO2 as the sole energy and carbon sources, respectively. However, to improve the productivity, one key issue needed to be addressed is the low tolerance of the photosynthetic hosts to butanol. Results In this study, we first applied a quantitative transcriptomics approach with a next-generation RNA sequencing technology to identify gene targets relevant to butanol tolerance in a model cyanobacterium Synechocystis sp. PCC 6803. The results showed that 278 genes were induced by the butanol exposure at all three sampling points through the growth time course. Genes encoding heat-shock proteins, oxidative stress related proteins, transporters and proteins involved in common stress responses, were induced by butanol exposure. We then applied GC-MS based metabolomics analysis to determine the metabolic changes associated with the butanol exposure. The results showed that 46 out of 73 chemically classified metabolites were differentially regulated by butanol treatment. Notably, 3-phosphoglycerate, glycine, serine and urea related to general stress responses were elevated in butanol-treated cells. To validate the potential targets, we constructed gene knockout mutants for three selected gene targets. The comparative phenotypic analysis confirmed that these genes were involved in the butanol tolerance. Conclusion The integrated OMICS analysis provided a comprehensive view of the complicated molecular mechanisms employed by Synechocystis sp. PCC 6803 against butanol stress, and allowed identification of a series of potential gene candidates for tolerance engineering in cyanobacterium Synechocystis sp. PCC 6803. PMID:23883549

  15. Comprehensive molecular characterization of Methylobacterium extorquens AM1 adapted for 1-butanol tolerance

    DOE PAGES

    Hu, Bo; Yang, Yi -Ming; Beck, David A. C.; ...

    2016-04-11

    In this study, the toxicity of alcohols is one of the major roadblocks of biological fermentation for biofuels production. Methylobacterium extorquens AM1, a facultative methylotrophic α-proteobacterium, has been engineered to generate 1-butanol from cheap carbon feedstocks through a synthetic metabolic pathway. However, M. extorquens AM1 is vulnerable to solvent stress, which impedes further development for 1-butanol production. Only a few studies have reported the general stress response of M. extorquens AM1 to solvent stress. Therefore, it is highly desirable to obtain a strain with ameliorated 1-butanol tolerance and elucidate the molecular mechanism of 1-butnaol tolerance in M. extorquens AM1 formore » future strain improvement. In this work, adaptive laboratory evolution was used as a tool to isolate mutants with 1-butanol tolerance up to 0.5 %. The evolved strains, BHBT3 and BHBT5, demonstrated increased growth rates and higher survival rates with the existence of 1-butanol. Whole genome sequencing revealed a SNP mutation at kefB in BHBT5, which was confirmed to be responsible for increasing 1-butanol tolerance through an allelic exchange experiment. Global metabolomic analysis further discovered that the pools of multiple key metabolites, including fatty acids, amino acids, and disaccharides, were increased in BHBT5 in response to 1-butanol stress. Additionally, the carotenoid synthesis pathway was significantly down-regulated in BHBT5. In conclusion, we successfully screened mutants resistant to 1-butanol and provided insights into the molecular mechanism of 1-butanol tolerance in M. extorquens AM1. This research will be useful for uncovering the mechanism of cellular response of M. extorquens AM1 to solvent stress, and will provide the genetic blueprint for the rational design of a strain of M. extorquens AM1 with increased 1-butanol tolerance in the future.« less

  16. Anaphylactoid reaction to ethanol.

    PubMed

    Kelso, J M; Keating, M U; Squillace, D L; O'Connell, E J; Yunginger, J W; Sachs, M I

    1990-05-01

    We studied a 14-year-old boy who developed a pruritic rash and facial swelling after ingestion of beer or wine. A blinded challenge with purified ethanol was positive demonstrating ethanol itself to be the offending agent. An IgE-mediated reaction to ethanol or one of its metabolites as a hapten is possible, or the reaction may involve unusual metabolism of ethanol with accumulation of acetaldehyde and/or direct mast cell degranulation.

  17. Ethanol Enhances Hepatitis C Virus Replication through Lipid Metabolism and Elevated NADH/NAD+*

    PubMed Central

    Seronello, Scott; Ito, Chieri; Wakita, Takaji; Choi, Jinah

    2010-01-01

    Ethanol has been suggested to elevate HCV titer in patients and to increase HCV RNA in replicon cells, suggesting that HCV replication is increased in the presence and absence of the complete viral replication cycle, but the mechanisms remain unclear. In this study, we use Huh7 human hepatoma cells that naturally express comparable levels of CYP2E1 as human liver to demonstrate that ethanol, at subtoxic and physiologically relevant concentrations, enhances complete HCV replication. The viral RNA genome replication is affected for both genotypes 2a and 1b. Acetaldehyde, a major product of ethanol metabolism, likewise enhances HCV replication at physiological concentrations. The potentiation of HCV replication by ethanol is suppressed by inhibiting CYP2E1 or aldehyde dehydrogenase and requires an elevated NADH/NAD+ ratio. In addition, acetate, isopropyl alcohol, and concentrations of acetone that occur in diabetics enhance HCV replication with corresponding increases in the NADH/NAD+. Furthermore, inhibiting the host mevalonate pathway with lovastatin or fluvastatin and fatty acid synthesis with 5-(tetradecyloxy)-2-furoic acid or cerulenin significantly attenuates the enhancement of HCV replication by ethanol, acetaldehyde, acetone, as well as acetate, whereas inhibiting β-oxidation with β-mercaptopropionic acid increases HCV replication. Ethanol, acetaldehyde, acetone, and acetate increase the total intracellular cholesterol content, which is attenuated with lovastatin. In contrast, both endogenous and exogenous ROS suppress the replication of HCV genotype 2a, as previously shown with genotype 1b. Conclusion: Therefore, lipid metabolism and alteration of cellular NADH/NAD+ ratio are likely to play a critical role in the potentiation of HCV replication by ethanol rather than oxidative stress. PMID:19910460

  18. Ethanol Basics (Fact Sheet)

    SciTech Connect

    Not Available

    2015-01-01

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  19. Ethanol has different effects on Ca(2+)-transport ATPases of muscle, brain and blood platelets.

    PubMed Central

    Mitidieri, F; de Meis, L

    1995-01-01

    The effects of ethanol on different sarco/endoplasmic reticulum Ca(2+)-transport ATPases (SERCAs) were studied. In sarcoplasmic reticulum vesicles, ethanol concentrations varying from 5 to 20% promoted a progressive inhibition of Ca2+ uptake, enhancement of Ca2+ efflux, activation of the ATPase activity, increase of the enzyme phosphorylation by ATP and inhibition of enzyme phosphorylation by P1. The effects of ethanol on Ca2+ uptake and Ca2+ efflux were antagonized by Mg2+, P(i) and spermine. The increased efflux promoted by ethanol was antagonized by Ca2+ and thapsigargin. In brain and platelet vesicles a biphasic effect of ethanol was observed, so that activation occurred at low concentrations (5-10%) and inhibition at higher concentrations. The activation was not observed with the use of n-propanol and n-butanol. Different from the situation in sarcoplasmic reticulum, the decrease of the Ca2+ uptake in brain and platelet vesicles was associated with an inhibition of the ATPase activity. Mg2+ and P(i) antagonized the enhancement of Ca2+ efflux and the inhibition of Ca2+ uptake promoted by ethanol. However, thapsigargin and Ca2+ did not arrest the Ca2+ efflux promoted by ethanol in brain and platelet preparations. These results suggest that, in sarcoplasmic reticulum vesicles, ethanol uncouples the pump, promoting its activity as a Ca2+ channel. The SERCA isoform found in skeletal muscle has different properties from the isoforms found in brain and blood platelets. PMID:8554513

  20. Insights into Acetone Photochemistry on Rutile TiO2(110). 1. Off-Normal CH3 Ejection from Acetone Diolate.

    SciTech Connect

    Petrik, Nikolay G.; Henderson, Michael A.; Kimmel, Gregory A.

    2015-06-04

    Thermal- and photon-stimulated reactions of acetone co-adsorbed with oxygen on rutile TiO2(110) surface are studied with infrared reflection-adsorption spectroscopy (IRAS) combined with temperature programmed desorption and angle-resolved photon stimulated desorption. IRAS results show that n2-acetone diolate ((CH3)2COO) is produced via thermally-activated reactions between the chemisorbed oxygen with co-adsorbed acetone. Formation of acetone diolate is also consistent with 18O / 16O isotopic exchange experiments. During UV irradiation at 30 K, CH3 radicals are ejected from the acetone diolate with a distribution that is peaked at .-. +- 66 degrees from the surface normal along the azimuth (i.e. perpendicular to the rows of bridging oxygen and Ti5c ions). This distribution is also consistent with the orientation of the C–CH3 bonds in the n2-acetone diolate on TiO2(110). The acetone diolate peaks disappear from the IRAS spectra after UV irradiation and new peaks are observed and associated with n2-acetate. The data presented here demonstrate direct signatures of the proposed earlier 2-step mechanism for acetone photooxidation on TiO2(110)

  1. Ethanol production by thermophilic bacteria: metabolic control of end product formation in Thermoanaerobium brockii

    SciTech Connect

    Ben-Bassat, A.; Lamed, R.; Zeikus, J.G.

    1981-04-01

    Specific changes in the chemical and microbial composition fof Thermoanaerobium brockii fermentations were compared and related to alterations of process rates, end product yields, and growth parameters. Fermentation of starch as compared with glucose was associated with significant decreases in growth rate and intracellular fructose-1,6-bisphosphate concentration and with a dramatic increase in the ethanols/lactate product ratio. Glucose or pyruvate fermentation in the presence of acetone was correlated with increased substrate consumption, growth, acetate yield, and quantitative reduction of acetone to isopropanol in lieu of normal reduced fermentation products. Glucose fermentation in the presence of exogenous hydrogen was associated with inhibition of endogenous H/sub 2/ production. The effects of exogenous hydrogen on glucose fermentation were totally reversed by the addition of acetone. Glucose fermentation in coculture with Methanobacterium thermoautotrophicum correlated with increased growth, acetate yield, and the formation of methane in lieu of monoculture reduced products.

  2. A sensitivity analysis of key natural factors in the modeled global acetone budget

    NASA Astrophysics Data System (ADS)

    Brewer, J. F.; Bishop, M.; Kelp, M.; Keller, C. A.; Ravishankara, A. R.; Fischer, E. V.

    2017-02-01

    Acetone is one of the most abundant carbonyl compounds in the atmosphere, and it serves as an important source of HOx (OH + HO2) radicals in the upper troposphere and a precursor for peroxyacetyl nitrate. We present a global sensitivity analysis targeted at several major natural source and sink terms in the global acetone budget to find the input factor or factors to which the simulated acetone mixing ratio was most sensitive. The ranges of input factors were taken from literature. We calculated the influence of these factors in terms of their elementary effects on model output. Of the six factors tested here, the four factors with the highest contribution to total global annual model sensitivity are direct emissions of acetone from the terrestrial biosphere, acetone loss to photolysis, the concentration of acetone in the ocean mixed layer, and the dry deposition of acetone to ice-free land. The direct emissions of acetone from the terrestrial biosphere are globally important in determining acetone mixing ratios, but their importance varies seasonally outside the tropics. Photolysis is most influential in the upper troposphere. Additionally, the influence of the oceanic mixed layer concentrations are relatively invariant between seasons, compared to the other factors tested. Monoterpene oxidation in the troposphere, despite the significant uncertainties in acetone yield in this process, is responsible for only a small amount of model uncertainty in the budget analysis.

  3. Molybdenum disulfide catalyzed tungsten oxide for on-chip acetone sensing

    NASA Astrophysics Data System (ADS)

    Li, Hong; Ahn, Sung Hoon; Park, Sangwook; Cai, Lili; Zhao, Jiheng; He, Jiajun; Zhou, Minjie; Park, Joonsuk; Zheng, Xiaolin

    2016-09-01

    Acetone sensing is critical for acetone leak detection and holds a great promise for the noninvasive diagnosis of diabetes. It is thus highly desirable to develop a wearable acetone sensor that has low cost, miniature size, sub-ppm detection limit, great selectivity, as well as low operating temperature. In this work, we demonstrate a cost-effective on-chip acetone sensor with excellent sensing performances at 200 °C using molybdenum disulfide (MoS2) catalyzed tungsten oxide (WO3). The WO3 based acetone sensors are first optimized via combined mesoscopic nanostructuring and silicon doping. Under the same testing conditions, our optimized mesoporous silicon doped WO3 [Si:WO3(meso)] sensor shows 2.5 times better sensitivity with ˜1000 times smaller active device area than the state-of-art WO3 based acetone sensor. Next, MoS2 is introduced to catalyze the acetone sensing reactions for Si:WO3(meso), which reduces the operating temperature by 100 °C while retaining its high sensing performances. Our miniaturized acetone sensor may serve as a wearable acetone detector for noninvasive diabetes monitoring or acetone leakage detection. Moreover, our work demonstrates that MoS2 can be a promising nonprecious catalyst for catalytic sensing applications.

  4. Phase transitions of amorphous solid acetone in confined geometry investigated by reflection absorption infrared spectroscopy.

    PubMed

    Shin, Sunghwan; Kang, Hani; Kim, Jun Soo; Kang, Heon

    2014-11-26

    We investigated the phase transformations of amorphous solid acetone under confined geometry by preparing acetone films trapped in amorphous solid water (ASW) or CCl4. Reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) were used to monitor the phase changes of the acetone sample with increasing temperature. An acetone film trapped in ASW shows an abrupt change in the RAIRS features of the acetone vibrational bands during heating from 80 to 100 K, which indicates the transformation of amorphous solid acetone to a molecularly aligned crystalline phase. Further heating of the sample to 140 K produces an isotropic solid phase, and eventually a fluid phase near 157 K, at which the acetone sample is probably trapped in a pressurized, superheated condition inside the ASW matrix. Inside a CCl4 matrix, amorphous solid acetone crystallizes into a different, isotropic structure at ca. 90 K. We propose that the molecularly aligned crystalline phase formed in ASW is created by heterogeneous nucleation at the acetone-water interface, with resultant crystal growth, whereas the isotropic crystalline phase in CCl4 is formed by homogeneous crystal growth starting from the bulk region of the acetone sample.

  5. Acetone PLIF concentration measurements in a submerged round turbulent jet

    NASA Astrophysics Data System (ADS)

    Kravtsov, Z. D.; Chikishev, L. M.; Dulin, V. M.

    2016-10-01

    Transport of passive scalar in near-field of a submerged turbulent jet, was studied experimentally by using the planar laser-induced fluorescence technique. The jet issued from a round pipe with the inner diameter and length of 21 mm and 700 mm, respectively. Three cases of Reynolds numbers were studied: Re=3000, 6000, and 9000. Vapor of acetone, mixed to the jet flow, served as a passive fluorescent tracer. The paper describes data processing utilized to convert intensity of fluorescence images to the instantaneous concentration.

  6. Process parameters for operating 1-butanol gas stripping in a fermentor.

    PubMed

    Liao, Ying-Chen; Lu, Kuan-Ming; Li, Si-Yu

    2014-11-01

    In this study, effects of the agitation speed, the flow rate, and type of non-polar gases on the performance of gas stripping was systematically investigated. Macroscopically, the stripping rate of butanol is linearly proportional to the concentration of butanol in the feed solution. Nevertheless, a decrease in butanol selectivity was observed with the increasing butanol concentrations up to 0.01 g/cm(3). This can be attributed to the thermodynamics reason that with increasing butanol concentrations in the feed, more stripping gas will dissolve in the feed solution that decrease the activity of butanol for mass transfer from liquids to gas bubbles. This can be supported by the use of highly soluble gas of carbon dioxide as the stripping gas where the Ksa dropped 48% compared to the nitrogen stripping. By the parameter sensitivity analysis, it has been shown that the dominant variable is the flow rate. The best strategy of maximizing the performance of 1-butanol gas stripping at a given flow rate is to bubble the gases at a high superficial velocity, which leads to a less resistance on the liquid side for mass transfer.

  7. Metabolic engineering of a synergistic pathway for n-butanol production in Saccharomyces cerevisiae

    PubMed Central

    Shi, Shuobo; Si, Tong; Liu, Zihe; Zhang, Hongfang; Ang, Ee Lui; Zhao, Huimin

    2016-01-01

    n-Butanol has several favourable properties as an advanced fuel or a platform chemical. Bio-based production of n-butanol is becoming increasingly important for sustainable chemical industry. Synthesis of n-butanol can be achieved via more than one metabolic pathway. Here we report the metabolic engineering of Saccharomyces cerevisiae to produce n-butanol through a synergistic pathway: the endogenous threonine pathway and the introduced citramalate pathway. Firstly, we characterized and optimized the endogenous threonine pathway; then, a citramalate synthase (CimA) mediated pathway was introduced to construct the synergistic pathway; next, the synergistic pathway was optimized by additional overexpression of relevant genes identified previously; meanwhile, the n-butanol production was also improved by overexpression of keto-acid decarboxylases (KDC) and alcohol dehydrogenase (ADH). After combining these strategies with co-expression of LEU1 (two copies), LEU4, LEU2 (two copies), LEU5, CimA, NFS1, ADH7 and ARO10*, we achieved an n-butanol production of 835 mg/L in the final engineered strain, which is almost 7-fold increase compared to the initial strain. Furthermore, the production showed a 3-fold of the highest titer ever reported in yeast. Therefore, the engineered yeast strain represents a promising alternative platform for n-butanol production. PMID:27161023

  8. Evaluation of developmental toxicity of 1-butanol given to rats in drinking water throughout pregnancy.

    PubMed

    Ema, M; Hara, H; Matsumoto, M; Hirose, A; Kamata, E

    2005-02-01

    The objective of this study was to evaluate the developmental toxicity of 1-butanol in rats. Pregnant rats were given drinking water containing 1-butanol at 0.2%, 1.0% or 5.0% (316, 1454 or 5654 mg/kg/day) on days 0-20 of pregnancy. A significant decrease in maternal body weight gain accompanied by reduced food and water consumption was found at 5.0%. No significant increase in the incidence of pre- and postimplantation embryonic loss was observed in any groups treated with 1-butanol. Fetal weight was significantly lowered at 5.0%. Although a significant increase in the incidence of fetuses with skeletal variations and decreased degree of ossification was found at 5.0%, no increase in the incidence of fetuses with external, skeletal and internal abnormalities was detected in any groups treated with 1-butanol. The data demonstrate that 1-butanol is developmental toxic only at maternal toxic doses. No evidence for teratogenicity of 1-butanol was noted in rats. Based on the significant decreases in maternal body weight gain and fetal weight, it is concluded that the no observed adverse effect levels (NOAELs) of 1-butanol for both dams and fetuses are 1.0% (1454 mg/kg/day) in rats.

  9. Purification and characterization of 4-N-trimethylamino-1-butanol dehydrogenase from Fusarium merismoides var. acetilereum.

    PubMed

    Fujimitsu, Hiroshi; Taniyama, Yuko; Tajima, Sae; Mohamed Ahmed, Isam A; Arima, Jiro; Mori, Nobuhiro

    2016-09-01

    From investigation of 60 filamentous fungi, we identified Fusarium merismoides var. acetilereum, which uses 4-N-trimethylamino-1-butanol (TMA-butanol) as the sole source of carbon and nitrogen. The fungus produced NAD(+)-dependent TMA-butanol dehydrogenase (DH) when it was cultivated in medium containing TMA-butanol. The enzyme showed molecular mass of 40 kDa by SDS-PAGE and 160 kDa by gel filtration, suggesting that it is a homotetramer. TMA-butanol DH is stable at pH 7.5-9.0. It exhibits moderate stability with respect to temperature (up to 30 °C). Additionally, it has optimum activity at 45 °C and at pH 9.5. The enzyme has broad specificity to various alkyl alcohols and amino alkyl alcohols, and the carbon chains of which are longer than butanol. Moreover, the activity is strongly inhibited by oxidizing agents, carbonyl and thiol modulators, and chelating agents. This report is the first study examining TMA-butanol DH from eukaryotic microbes.

  10. Low and High Temperature Combustion Chemistry of Butanol Isomers in Premixed Flames and Autoignition Systems

    SciTech Connect

    Sarathy, S M; Pitz, W J; Westbrook, C K; Mehl, M; Yasunaga, K; Curran, H J; Tsujimura, T; Osswald, P; Kohse-Hoinghaus, K

    2010-12-12

    Butanol is a fuel that has been proposed as a bio-derived alternative to conventional petroleum derived fuels. The structural isomer in traditional 'bio-butanol' fuel is n-butanol, but newer conversion technologies produce iso-butanol as a fuel. In order to better understand the combustion chemistry of bio-butanol, this study presents a comprehensive chemical kinetic model for all the four isomers of butanol (e.g., 1-, 2-, iso- and tert-butanol). The proposed model includes detailed high temperature and low temperature reaction pathways. In this study, the primary experimental validation target for the model is premixed flat low-pressure flame species profiles obtained using molecular beam mass spectrometry (MBMS). The model is also validated against previously published data for premixed flame velocity and n-butanol rapid compression machine and shock tube ignition delay. The agreement with these data sets is reasonably good. The dominant reaction pathways at the various pressures and temperatures studied are elucidated. At low temperature conditions, we found that the reaction of alphahydroxybutyl with O{sub 2} was important in controlling the reactivity of the system, and for correctly predicting C{sub 4} aldehyde profiles in low pressure premixed flames. Enol-keto isomerization reactions assisted by HO{sub 2} were also found to be important in converting enols to aldehydes and ketones in the low pressure premixed flames. In the paper, we describe how the structural features of the four different butanol isomers lead to differences in the combustion properties of each isomer.

  11. Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.; Tai, D.Y.

    1988-01-01

    The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the time-of-travel and dispersion characteristics of the stream. A 12-h injection of t-butyl alcohol (TBA) was used to determine the volatilization characteristics of the stream. Volatilization controlled the acetone concentration in the stream. Significant bacterial degradation of acetone did not occur, contrary to expectations based on previous laboratory studies. Attempts to induce degradation of the acetone by injecting glucose and a nutrient solution containing bacteria acclimated to acetone were unsuccessful. Possible explanations for the lack of bacterial degradation included a nitrate limitation and a limited residence time in the stream system. ?? 1988.

  12. The Effect of Fluorocarbon Surfactant Additives on the Effective Viscosity of Acetone Solutions of Cellulose Diacetate,

    DTIC Science & Technology

    2014-09-26

    34 FOREIGN TECHNOLOGY DIVISION i00 Lfl .. THE EFFECT OF FLUOROCARBON SURFACTANT ADDITIVES ON THE EFFECTIVE VISCOSITY OF ACETONE SOLUTIONS OF CELLULOSE...ADDITIVES ON TH~ .. t- ’_ ition EFFECTIVE VISCOSITY OF ACETONE SOLUTIONS OF CELLULOSE DIACETATE D~rbt~l By: L.A. Shits, N. Yu. Kal’nova Codesuton English...VISCOSITY OF ACETONE SOLUTIONS OF CELLULOSE DIACETATE L. A. Shits, N. Yu. Kal’nova (Institute of Physical Chemistry of the AS USSR, Moscow) ! - The

  13. Application of LaserBreath-001 for breath acetone measurement in subjects with diabetes mellitus

    NASA Astrophysics Data System (ADS)

    Wang, Zhennan; Sun, Meixiu; Chen, Zhuying; Zhao, Xiaomeng; Li, Yingxin; Wang, Chuji

    2016-11-01

    Breath acetone is a promising biomarker of diabetes mellitus. With an integrated standalone, on-site cavity ringdown breath acetone analyzer, LaserBreath-001, we tested breath samples from 23 type 1 diabetic (T1D) patients, 312 type 2 diabetic (T2D) patients, 52 healthy subjects. In the cross-sectional studies, the obtained breath acetone concentrations were higher in the diabetic subjects compared with those in the control group. No correlation between breath acetone and simultaneous BG was observed in the T1D, T2D, and healthy subjects. A moderate positive correlation between the mean individual breath acetone concentrations and the mean individual BG levels was observed in the 20 T1D patients without ketoacidosis. In a longitudinal study, the breath acetone concentrations in a T1D patient with ketoacidosis decreased significantly and remained stable during the 5-day hospitalization. The results from a relatively large number of subjects tested indicate that an elevated mean breath acetone concentration exists in diabetic patients in general. Although many physiological parameters affect breath acetone concentrations, fast (<1 min) and on site breath acetone measurement can be used for diabetic screening and management under a specifically controlled condition.

  14. Fluorometric biosniffer (biochemical gas sensor) for breath acetone as a volatile indicator of lipid metabolism

    NASA Astrophysics Data System (ADS)

    Mitsubayashi, Kohji; Chien, Po-Jen; Ye, Ming; Suzuki, Takuma; Toma, Koji; Arakawa, Takahiro

    2016-11-01

    A fluorometric acetone biosniffer (biochemical gas sensor) for assessment of lipid metabolism utilizing reverse reaction of secondary alcohol dehydrogenase was constructed and evaluated. The biosniffer showed highly sensitivity and selectivity for continuous monitoring of gaseous acetone. The measurement of breath acetone concentration during fasting and aerobic exercise were also investigated. The acetone biosniffer provides a novel analytical tool for noninvasive evaluation of human lipid metabolism and it is also expected to use for the clinical and physiological applications such as monitoring the progression of diabetes.

  15. Tunable catalytic properties of bi-functional mixed oxides in ethanol conversion to high value compounds

    SciTech Connect

    Ramasamy, Karthikeyan K.; Gray, Michel J.; Job, Heather M.; Smith, Colin D.; Wang, Yong

    2016-04-10

    tA highly versatile ethanol conversion process to selectively generate high value compounds is pre-sented here. By changing the reaction temperature, ethanol can be selectively converted to >C2alcohols/oxygenates or phenolic compounds over hydrotalcite derived bi-functional MgO–Al2O3cata-lyst via complex cascade mechanism. Reaction temperature plays a role in whether aldol condensationor the acetone formation is the path taken in changing the product composition. This article containsthe catalytic activity comparison between the mono-functional and physical mixture counterpart to thehydrotalcite derived mixed oxides and the detailed discussion on the reaction mechanisms.

  16. Tunable catalytic properties of bi-functional mixed oxides in ethanol conversion to high value compounds

    DOE PAGES

    Ramasamy, Karthikeyan K.; Gray, Michel; Job, Heather; ...

    2016-02-03

    Here, a highly versatile ethanol conversion process to selectively generate high value compounds is presented here. By changing the reaction temperature, ethanol can be selectively converted to >C2 alcohols/oxygenates or phenolic compounds over hydrotalcite derived bi-functional MgO–Al2O3 catalyst via complex cascade mechanism. Reaction temperature plays a role in whether aldol condensation or the acetone formation is the path taken in changing the product composition. This article contains the catalytic activity comparison between the mono-functional and physical mixture counterpart to the hydrotalcite derived mixed oxides and the detailed discussion on the reaction mechanisms.

  17. Tunable catalytic properties of bi-functional mixed oxides in ethanol conversion to high value compounds

    SciTech Connect

    Ramasamy, Karthikeyan K.; Gray, Michel; Job, Heather; Smith, Colin; Wang, Yong

    2016-02-03

    Here, a highly versatile ethanol conversion process to selectively generate high value compounds is presented here. By changing the reaction temperature, ethanol can be selectively converted to >C2 alcohols/oxygenates or phenolic compounds over hydrotalcite derived bi-functional MgO–Al2O3 catalyst via complex cascade mechanism. Reaction temperature plays a role in whether aldol condensation or the acetone formation is the path taken in changing the product composition. This article contains the catalytic activity comparison between the mono-functional and physical mixture counterpart to the hydrotalcite derived mixed oxides and the detailed discussion on the reaction mechanisms.

  18. Ethanol Vapor Sensing Properties of Triangular Silver Nanostructures Based on Localized Surface Plasmon Resonance

    PubMed Central

    Ma, Wenying; Yang, Huan; Wang, Weimin; Gao, Ping; Yao, Jun

    2011-01-01

    A sensitive volatile organic vapor sensor based on the LSPR properties of silver triangular nanoprisms is proposed in this paper. The triangular nanoprisms were fabricated by a nanosphere lithography (NSL) method. They have sharp vertices and edges, and are arranged in an ideal hexangular array. These characteristics ensure that they exhibit an excellent LSPR spectrum and a high sensitivity to the exterior environment changes. The LSPR spectra responding to ethanol vapor and four other volatile organic vapors—acetone, benzene, hexane and propanol—were measured with a UV-vis spectrometer in real time. Compared with the other four vapors, ethanol exhibits the highest sensitivity (∼0.1 nm/mg L−1) and the lowest detection limit (∼10 mg/L) in the spectral tests. The ethanol vapor test process is also fast (∼4 s) and reversible. These insights demonstrate that the triangular nanoprism based nano-sensor can be used in ethanol vapor detection applications. PMID:22164096

  19. By-product inhibition effects of ethanolic fermentation by Saccharomyces cerevisiae

    SciTech Connect

    Maiorella, B.; Blanch, H.W.; Wilke, C.R.

    1983-01-01

    Inhibition by secondary fermentation products may limit the ultimate productivity of new glucose to ethanol fermentation processes. New processes are under development whereby ethanol is selectively removed from the fermenting broth to eliminate ethanol inhibition effects. These processes can concentrate minor secondary products to the point where they become toxic to the yeast. Vacuum fermentation selectively concentrates nonvolatile products in the fermentation broth. Membrane fermentation systems may concentrate large molecules which are sterically blocked from membrane transport. Extractive fermentation systems, employing nonpolar solvents, may concentrate small organic acids. By-product production rates and inhibition levels in continuous fermentation with Saccharomyces cerevisiae have been determined for acetaldehyde, glycerol, formic, lactic, and acetic acids, 1-propanol, 2-methyl-1-butanol, and 2,3- butanediol to assess the potential effects of these by-products on new fermentation processes. Mechanisms are proposed for the various inhibition effects observed. (Refs. 15).

  20. By-product inhibition effects on ethanolic fermentation by Saccharomyces cerevisiae

    SciTech Connect

    Mairoella, B.; Blanch, H.W.; Wilke, C.R.

    1983-01-01

    Inhibition by secondary fermentation products may limit the ultimate productivity of new glucose to ethanol fermentation processes. New processes are under development whereby ethanol is selectively removed from the fermenting broth to eliminate ethanol inhibition effects. These processes can concentrate minor secondary products to the point where they become toxic to the yeast. Vacuum fermentation selectively concentrates nonvolatile products in the fermentation broth. Membrane fermentation systems may concentrate large molecules which are sterically blocked from membrane transport. Extractive fermentation systems, employing nonpolar solvents, may concentrate small organic acids. By-product production rates and inhibition levels in continuous fermentation with Saccharomyces cerevisiae have been determined for acetaldehyde, glycerol, formic, lactic, and acetic acids, 1-propanol, 2-methyl-1-butanol, and 2,3-butanediol to assess the potential effects of these by-products on new fermentation processes. Mechanisms are proposed for the various inhibition effects observed.

  1. Conversion of 2,3-butanediol to 2-butanol, olefins and fuels

    DOEpatents

    Lilga, Michael A.; Lee, Guo-Shuh; Lee, Suh-Jane

    2016-12-13

    Embodiments of an integrated method for step-wise conversion of 2,3-butanediol to 2-butanol, and optionally to hydrocarbons, are disclosed. The method includes providing an acidic catalyst, exposing a composition comprising aqueous 2,3-butanediol to the acidic catalyst to produce an intermediate composition comprising methyl ethyl ketone, providing a hydrogenation catalyst that is spatially separated from the acidic catalyst, and subsequently exposing the intermediate composition to the hydrogenation catalyst to produce a composition comprising 2-butanol. The method may further include subsequently exposing the composition comprising 2-butanol to a deoxygenation catalyst, and deoxygenating the 2-butanol to form hydrocarbons. In some embodiments, the hydrocarbons comprise olefins, such as butenes, and the method may further include subsequently exposing the hydrocarbons to a hydrogenation catalyst to form saturated hydrocarbons.

  2. Techno-economics of carbon preserving butanol production using a combined fermentative and catalytic approach.

    PubMed

    Nilsson, Robert; Bauer, Fredric; Mesfun, Sennai; Hulteberg, Christian; Lundgren, Joakim; Wännström, Sune; Rova, Ulrika; Berglund, Kris Arvid

    2014-06-01

    This paper presents a novel process for n-butanol production which combines a fermentation consuming carbon dioxide (succinic acid fermentation) with subsequent catalytic reduction steps to add hydrogen to form butanol. Process simulations in Aspen Plus have been the basis for the techno-economic analyses performed. The overall economy for the novel process cannot be justified, as production of succinic acid by fermentation is too costly. Though, succinic acid price is expected to drop drastically in a near future. By fully integrating the succinic acid fermentation with the catalytic conversion the need for costly recovery operations could be reduced. The hybrid process would need 22% less raw material than the butanol fermentation at a succinic acid fermentation yield of 0.7g/g substrate. Additionally, a carbon dioxide fixation of up to 13ktonnes could be achieved at a plant with an annual butanol production of 10ktonnes.

  3. Utilizing an endogenous pathway for 1-butanol production in Saccharomyces cerevisiae.

    PubMed

    Si, Tong; Luo, Yunzi; Xiao, Han; Zhao, Huimin

    2014-03-01

    Microbial production of higher alcohols from renewable feedstock has attracted intensive attention thanks to its potential as a source for next-generation gasoline substitutes. Here we report the discovery, characterization and engineering of an endogenous 1-butanol pathway in Saccharomyces cerevisiae. Upon introduction of a single gene deletion adh1Δ, S. cerevisiae was able to accumulate more than 120 mg/L 1-butanol from glucose in rich medium. Precursor feeding, ¹³C-isotope labeling and gene deletion experiments demonstrated that the endogenous 1-butanol production was dependent on catabolism of threonine in a manner similar to fusel alcohol production by the Ehrlich pathway. Specifically, the leucine biosynthesis pathway was engaged in the conversion of key 2-keto acid intermediates. Overexpression of the pathway enzymes and elimination of competing pathways achieved the highest reported 1-butanol titer in S. cerevisiae (242.8 mg/L).

  4. Modeling the Fate of Groundwater Contaminants Resulting from Leakage of Butanol-blended Fuel

    EPA Science Inventory

    The poster demonstrates the integration of MODFLOW2000 and modified RT3D, simulating flow and transport of remediation process results from leakage of Butanol and Benzene contained in alternative fuels.

  5. Fermentation method producing ethanol

    DOEpatents

    Wang, Daniel I. C.; Dalal, Rajen

    1986-01-01

    Ethanol is the major end product of an anaerobic, thermophilic fermentation process using a mutant strain of bacterium Clostridium thermosaccharolyticum. This organism is capable of converting hexose and pentose carbohydrates to ethanol, acetic and lactic acids. Mutants of Clostridium thermosaccharolyticum are capable of converting these substrates to ethanol in exceptionally high yield and with increased productivity. Both the mutant organism and the technique for its isolation are provided.

  6. Ethanol immunosuppression in vitro

    SciTech Connect

    Kaplan, D.R.

    1986-03-01

    Ethanol in concentrations equivalent to levels achieved by the ingestion of moderate to large amounts of alcoholic beverages has been shown to inhibit mitogen and anti-CD3 stimulated human T lymphocyte proliferation. This inhibition was monophasic suggesting that ethanol affected a single limiting component of T cell proliferation. In experiments designed to test the effect of ethanol on various aspects of proliferation, it was demonstrated that ethanol inhibited the capacity of exogenously supplied interleukin 2 to stimulate proliferation of T cells that had previously acquired interleukin 2 receptors in a monophasic, dose-dependent manner. Moreover, there was no suppression of interleukin 2 production or interleukin 2 receptor acquisition. Thus, ethanol was shown to mediate immunosuppression by a mechanism specific to one component of proliferation. Additive inhibition of T cell proliferation was seen with ethanol plus cyclosporin A which inhibits interleukin 2 production. The level of inhibition with 250 ng/ml cyclosporin A alone was equivalent to the level seen with 62 ng/ml cyclosporin A plus 20 mM (94 mg%) ethanol. Ethanol also suppressed an immune effector mechanism. NK cytotoxicity was depressed in a monophasic, dose-dependent manner. Thus, ethanol might be considered as a possible adjunct in immunosuppressive therapy.

  7. Expression of Clostridium acetobutylicum ATCC 824 Genes in Escherichia coli for Acetone Production and Acetate Detoxification

    PubMed Central

    Bermejo, Lourdes L.; Welker, Neil E.; Papoutsakis, Eleftherios T.

    1998-01-01

    A synthetic acetone operon (ace4) composed of four Clostridium acetobutylicum ATCC 824 genes (adc, ctfAB, and thl, coding for the acetoacetate decarboxylase, coenzyme A transferase, and thiolase, respectively) under the control of the thl promoter was constructed and was introduced into Escherichia coli on vector pACT. Acetone production demonstrated that ace4 is expressed in E. coli and resulted in the reduction of acetic acid levels in the fermentation broth. Since different E. coli strains vary significantly in their growth characteristics and acetate metabolism, ace4 was expressed in three E. coli strains: ER2275, ATCC 11303, and MC1060. Shake flask cultures of MC1060(pACT) produced ca. 2 mM acetone, while both strains ER2275(pACT) and ATCC 11303(pACT) produced ca. 40 mM acetone. Glucose-fed cultures of strain ATCC 11303(pACT) resulted in a 150% increase in acetone titers compared to those of batch shake flask cultures. External addition of sodium acetate to glucose-fed cultures of ATCC 11303(pACT) resulted in further increased acetone titers. In bioreactor studies, acidic conditions (pH 5.5 versus 6.5) improved acetone production. Despite the substantial acetone evaporation due to aeration and agitation in the bioreactor, 125 to 154 mM acetone accumulated in ATCC 11303(pACT) fermentations. These acetone titers are equal to or higher than those produced by wild-type C. acetobutylicum. This is the first study to demonstrate the ability to use clostridial genes in nonclostridial hosts for solvent production. In addition, acetone-producing E. coli strains may be useful hosts for recombinant protein production in that detrimental acetate accumulation can be avoided. PMID:9501448

  8. Evaluating the Potential Importance of Monoterpene Degradation for Global Acetone Production

    NASA Astrophysics Data System (ADS)

    Kelp, M. M.; Brewer, J.; Keller, C. A.; Fischer, E. V.

    2015-12-01

    Acetone is one of the most abundant volatile organic compounds (VOCs) in the atmosphere, but estimates of the global source of acetone vary widely. A better understanding of acetone sources is essential because acetone serves as a source of HOx in the upper troposphere and as a precursor to the NOx reservoir species peroxyacetyl nitrate (PAN). Although there are primary anthropogenic and pyrogenic sources of acetone, the dominant acetone sources are thought to be from direct biogenic emissions and photochemical production, particularly from the oxidation of iso-alkanes. Recent work suggests that the photochemical degradation of monoterpenes may also represent a significant contribution to global acetone production. We investigate that hypothesis using the GEOS-Chem chemical transport model. In this work, we calculate the emissions of eight terpene species (α-pinene, β-pinene, limonene, Δ3-carene, myrcene, sabinene, trans-β-ocimene, and an 'other monoterpenes' category which contains 34 other trace species) and couple these with upper and lower bound literature yields from species-specific chamber studies. We compare the simulated acetone distributions against in situ acetone measurements from a global suite of NASA aircraft campaigns. When simulating an upper bound on yields, the model-to-measurement comparison improves for North America at both the surface and in the upper troposphere. The inclusion of acetone production from monoterpene degradation also improves the ability of the model to reproduce observations of acetone in East Asian outflow. However, in general the addition of monoterpenes degrades the model comparison for the Southern Hemisphere.

  9. Molecular interactions in 1-butanol + IL solutions by measuring and modeling activity coefficients.

    PubMed

    Nann, Alexander; Mündges, Jan; Held, Christoph; Verevkin, Sergey P; Sadowski, Gabriele

    2013-03-21

    Molecular interactions in 1-butanol + ionic liquid (IL) solutions have been investigated by measuring and modeling activity-coefficient data. The activity coefficients in binary solutions containing 1-butanol and an IL were determined experimentally: the ILs studied were 1-decyl-3-methyl-imidazolium tetracyanoborate ([Im10.1](+)[tcb](-)), 4-decyl-4-methyl-morpholinium tetracyanoborate ([Mo10.1](+)[tcb](-)), 1-decyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide ([Im10.1](+)[ntf2](-)), and 4-decyl-4-methyl-morpholinium bis(trifluoromethylsulfonyl)imide ([Mo10.1](+)[ntf2](-)). The methods used to determine the activity coefficients included vapor-pressure osmometry, headspace-gas chromatography, and gas-liquid chromatography. The results from all of these techniques were combined to obtain activity-coefficient data over the entire IL concentration range, and the ion-specific interactions of the ILs investigated were identified with 1-butanol. The highest (1-butanol)-IL interactions of the ILs considered in this work were found for [Im10.1](+)[tcb](-); thus, [Im10.1](+)[tcb](-) showed the highest affinity for 1-butanol in a binary mixture. The experimental data were modeled with the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT). PC-SAFT was able to accurately describe the pure IL and (1-butanol)-IL data. Moreover, the model was shown to be predictive and extrapolative with respect to concentration and temperature.

  10. Metabolic engineering of cyanobacteria for 1-butanol production from carbon dioxide.

    PubMed

    Lan, Ethan I; Liao, James C

    2011-07-01

    Production of chemicals and fuels directly from CO(2) is an attractive approach to solving the energy and environmental problems. 1-Butanol, a chemical feedstock and potential fuel, has been produced by fermentation of carbohydrates, both in native Clostridium species and various engineered hosts. To produce 1-butanol from CO(2), we transferred a modified CoA-dependent 1-butanol production pathway into a cyanobacterium, Synechococcus elongatus PCC 7942. We demonstrated the activity of each enzyme in the pathway by chromosomal integration and expression of the genes. In particular, Treponema denticola trans-enoyl-CoA reductase (Ter), which utilizes NADH as the reducing power, was used for the reduction of crotonyl-CoA to butyryl-CoA instead of Clostridium acetobutylicum butyryl-CoA dehydrogenase to by-pass the need of Clostridial ferredoxins. Addition of polyhistidine-tag increased the overall activity of Ter and resulted in higher 1-butanol production. Removal of oxygen is an important factor in the synthesis of 1-butanol in this organism. This result represents the first autotrophic 1-butanol production.

  11. Butanol production by a Clostridium beijerinckii mutant with high ferulic acid tolerance.

    PubMed

    Liu, Jun; Guo, Ting; Wang, Dong; Xu, Jiahui; Ying, Hanjie

    2016-09-01

    A mutant strain of Clostridium beijerinckii, with high tolerance to ferulic acid, was generated using atmospheric pressure glow discharge and high-throughput screening of C. beijerinckii NCIMB 8052. The mutant strain M11 produced 7.24 g/L of butanol when grown in P2 medium containing 30 g/L of glucose and 0.5 g/L of ferulic acid, which is comparable to the production from non-ferulic acid cultures (8.11 g/L of butanol). When 0.8 g/L of ferulic acid was introduced into the P2 medium, C. beijerinckii M11 grew well and produced 4.91 g/L of butanol. Both cell growth and butanol production of C. beijerinckii M11 were seriously inhibited when 0.9 g/L of ferulic acid was added into the P2 medium. Furthermore, C. beijerinckii M11 could produce 6.13 g/L of butanol using non-detoxified hemicellulosic hydrolysate from diluted sulfuric acid-treated corn fiber (SAHHC) as the carbon source. These results demonstrate that C. beijerinckii M11 has a high ferulic acid tolerance and is able to use non-detoxified SAHHC for butanol production.

  12. Measurement of human cerebral blood flow with (15O)butanol and positron emission tomography

    SciTech Connect

    Berridge, M.S.; Adler, L.P.; Nelson, A.D.; Cassidy, E.H.; Muzic, R.F.; Bednarczyk, E.M.; Miraldi, F. )

    1991-09-01

    Although H2(15)O is widely used for CBF measurement by positron tomography, it underestimates CBF, especially at elevated flow rates. Several tracers, including butanol, overcome this problem, but the short half-life of 15O provides advantages that cause water to remain the tracer of choice. The authors report the first use and evaluation of 15O-labeled butanol for CBF measurement. Flow measurements made in a similar fashion with water and butanol at 10-min intervals were compared in normal volunteers under resting and hypercapnic conditions. Regional analysis showed good agreement between the tracers at low flows, and significant underestimation of flow by water relative to butanol in regions of elevated flow. The observed relationship between the tracers and the curve-fitted permeability-surface area product for water (133 ml.100 g-1.min-1) follow the known relationship between water and true flow. These observations indicate that (15O)-butanol provided accurate measurements of human regional CBF under conditions of elevated perfusion. They conclude that butanol is a convenient and accurate method for routine CBF determination by positron emission tomography.

  13. Antioxidant potential of n-butanol fraction from extract of Jasminum mesnyi Hance leaves.

    PubMed

    Borar, Sakshi; Punia, Priyanka; Kalia, A N

    2011-01-01

    Methanolic extract of Jasminum mesnyi Hance leaves having antidiabetic activity was subjected to fractionation to obtain antioxidant and antihyperglycemic rich fraction. Different concentrations of ethyl acetate and n-butanol fractions were subjected to antioxidant assay by DPPH method, nitric oxide scavenging activity and reducing power assay. The fractions showed dose dependent free radical scavenging property in all the models. IC50 values for ethyl acetate and n-butanol fractions were 153.45 +/- 6.65 and 6.22 +/- 0.25 microg/ml, respectively, as compared to L-ascorbic acid and rutin (as standards; IC50 values 6.54 +/- 0.24 and 5.43 +/- 0.21 microg/ml, respectively) in DPPH model. In nitric oxide scavenging activity, IC50 values were 141.54 +/- 9.95 microg/ml, 35.12 +/- 1.58 microg/ml, 21.06 +/- 0.95 microg/ml and 29.93 +/- 0.32 microg/ml for ethyl acetate, n-butanol fractions, L-ascorbic acid and rutin, respectively. n-Butanol fraction showed a good reducing potential and better free radical scavenging activity as compared to ethyl acetate fraction. Potent antioxidant n-butanol fraction showed better oral glucose tolerance test (antihyperglycemic) at par with metformin (standard drug), n-Butanol fraction contained secoiridoid glycosides which might be responsible for both antioxidant and antihyperglycemic activity.

  14. ARTP mutation and genome shuffling of ABE fermentation symbiotic system for improvement of butanol production.

    PubMed

    Gu, Chunkai; Wang, Genyu; Mai, Shuai; Wu, Pengfei; Wu, Jianrong; Wang, Gehua; Liu, Hongjuan; Zhang, Jianan

    2017-03-01

    Butanol is an ideal renewable biofuel which possesses superior fuel properties. Previously, butanol-producing symbiotic system TSH06 was isolated in our lab, with microoxygen tolerance ability. To boost butanol yield for large-scale industrial production, TSH06 was used as parental strain and subjected to atmospheric and room temperature plasma (ARTP) and four rounds of genome shuffling (GS). ARTP mutant and GS strain were co-cultured with facultative anaerobic Bacillus cereus TSH2 to form a symbiotic system with microoxygen tolerance, which was then subjected to fermentation. Relative messenger RNA (mRNA) level of key enzyme gene was measured by real-time PCR. The highest butanol titer of TS4-30 reached 15.63 g/L, which was 34% higher than TSH06 (12.19 g/L). Compared with parental strain, mRNA of acid-forming gene in TS4-30 decreased in acidogenesis phase, while solvent-forming gene increased in solventogenesis phase. This gene expression pattern was consistent with high butanol yield and low acid level in TS4-30. In summary, symbiotic system TS4-30 was obtained with butanol titer improvement and microoxygen tolerance.

  15. Acetone-CO enhancement ratios in the upper troposphere based on 7 years of CARIBIC data: new insights and estimates of regional acetone fluxes

    NASA Astrophysics Data System (ADS)

    Fischbeck, Garlich; Bönisch, Harald; Neumaier, Marco; Brenninkmeijer, Carl A. M.; Orphal, Johannes; Brito, Joel; Becker, Julia; Sprung, Detlev; van Velthoven, Peter F. J.; Zahn, Andreas

    2017-02-01

    Acetone and carbon monoxide (CO) are two important trace gases controlling the oxidation capacity of the troposphere; enhancement ratios (EnRs) are useful in assessing their sources and fate between emission and sampling, especially in pollution plumes. In this study, we focus on in situ data from the upper troposphere recorded by the passenger-aircraft-based IAGOS-CARIBIC (In-service Aircraft for a Global Observing System-Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) observatory over the periods 2006-2008 and 2012-2015. This dataset is used to investigate the seasonal and spatial variation of acetone-CO EnRs. Furthermore, we utilize a box model accounting for dilution, chemical degradation and secondary production of acetone from precursors. In former studies, increasing acetone-CO EnRs in a plume were associated with secondary production of acetone. Results of our box model question this common presumption and show increases of acetone-CO EnR over time without taking secondary production of acetone into account. The temporal evolution of EnRs in the upper troposphere, especially in summer, is not negligible and impedes the interpretation of EnRs as a means for partitioning of acetone and CO sources in the boundary layer. In order to ensure that CARIBIC EnRs represent signatures of source regions with only small influences by dilution and chemistry, we limit our analysis to temporal and spatial coherent events of high-CO enhancement. We mainly focus on North America and Southeast Asia because of their different mix of pollutant sources and the good data coverage. For both regions, we find the expected seasonal variation in acetone-CO EnRs with maxima in summer, but with higher amplitude over North America. We derive mean (± standard deviation) annual acetone fluxes of (53 ± 27) 10-13 kg m-2 s-1 and (185 ± 80) 10-13 kg m-2 s-1 for North America and Southeast Asia, respectively. The derived flux for North America

  16. Production of 2-methyl-1-butanol in engineered Escherichia coli.

    PubMed

    Cann, Anthony F; Liao, James C

    2008-11-01

    Recent progress has been made in the production of higher alcohols by harnessing the power of natural amino acid biosynthetic pathways. Here, we describe the first strain of Escherichia coli developed to produce the higher alcohol and potential new biofuel 2-methyl-1-butanol (2MB). To accomplish this, we explored the biodiversity of enzymes catalyzing key parts of the isoleucine biosynthetic pathway, finding that AHAS II (ilvGM) from Salmonella typhimurium and threonine deaminase (ilvA) from Corynebacterium glutamicum improve 2MB production the most. Overexpression of the native threonine biosynthetic operon (thrABC) on plasmid without the native transcription regulation also improved 2MB production in E. coli. Finally, we knocked out competing pathways upstream of threonine production (DeltametA, Deltatdh) to increase its availability for further improvement of 2MB production. This work led to a strain of E. coli that produces 1.25 g/L 2MB in 24 h, a total alcohol content of 3 g/L, and with yields of up to 0.17 g 2MB/g glucose.

  17. Influence of dynamic hand-grip exercise on acetone in gas emanating from human skin.

    PubMed

    Mori, Kenji; Funada, Toshiaki; Kikuchi, Maasa; Ohkuwa, Tetsuo; Itoh, Hiroshi; Yamazaki, Yoshihiko; Tsuda, Takao

    2008-01-01

    This study investigated the effects of dynamic hand-grip exercise on skin-gas acetone concentration. The subjects for this experiment were seven healthy males. In the first experiment, to ascertain the reproducibility of the results for the skin-gas acetone concentration test, the skin gas was collected four times from one subject. In the second experiment, all subjects performed three different types of exercise (Exercises I-III) for a duration of 60 s. Exercise I was performed at 10 kg with one contraction every 3 s. Exercise II was 30 kg with one contraction every 3 s. Exercise III was 10 kg with one contraction per second. Acetone concentration was analyzed by gas chromatography. In the first experiment, reasonable reproducibility was obtained in measurements of skin-gas acetone concentration during the hand-grip exercise. In the second experiment, acetone concentration in skin gas during hand-grip exercise II was significantly higher than the basal level. Although skin-gas acetone levels increased in all subjects during exercises I and III, a significant difference was not found. No significant difference was found in skin-gas acetone concentration during dynamic hand-grip exercise among exercises I, II, and III. This study confirmed that skin-gas acetone levels increase during dynamic hand-grip exercise.

  18. Influence of cycle exercise on acetone in expired air and skin gas.

    PubMed

    Yamai, Kazuaki; Ohkuwa, Tetsuo; Itoh, Hiroshi; Yamazaki, Yoshihiko; Tsuda, Takao

    2009-01-01

    This study investigated the influence of cycle exercise on acetone concentration in expired air and skin gas. The subjects for this experiment were eight healthy males. Subjects performed a continuous graded exercise test on a cycle ergometer. The workloads were 360 (1.0 kg), 720 (2.0 kg), 990 (2.75 kg) kgm/min, and each stage was 5 min in duration. A pedaling frequency of 60 rpm was maintained. Acetone concentration was analyzed by gas chromatography. The acetone concentration in expired air and skin gas during exercise at 990 kgm/min intensity was significantly increased compared with the basal level. The skin-gas acetone concentration at 990 kgm/min significantly increased compared with the 360 kgm/min (P < 0.05). The acetone excretion of expired air at 720 kgm/min and 990 kgm/min significantly increased compared with the basal level (P < 0.05). Acetone concentration in expired air was 4-fold greater than skin gas at rest and 3-fold greater during exercise (P < 0.01). Skin gas acetone concentration significantly related with expired air (r = 0.752; P < 0.01). This study confirmed that the skin-gas acetone concentration reflected that of expired air.

  19. Ethanol tolerance in bacteria.

    PubMed

    Ingram, L O

    1990-01-01

    The adverse effects of ethanol on bacterial growth, viability, and metabolism are caused primarily by ethanol-induced leakage of the plasma membrane. This increase in membrane leakage is consistent with known biophysical properties of membranes and ethanolic solutions. The primary actions of ethanol result from colligative effects of the high molar concentrations rather than from specific interactions with receptors. The ethanol tolerance of growth in different microorganisms appears to result in large part from adaptive and evolutionary changes in cell membrane composition. Different cellular activities vary in their tolerance to ethanol. Therefore, it is essential that the aspect of cellular function under study be specifically defined and that comparisons of ethanol tolerance among systems share this common definition. Growth is typically one of the most sensitive cellular activities to inhibition by ethanol, followed by survival, or loss of reproductive ability. Glycolysis is the most resistant of these three activities. Since glycolysis is an exergonic process, a cell need not be able to grow or remain viable for glycolysis to occur.

  20. Infrared spectroscopy of acetone-methanol liquid mixtures: Hydrogen bond network

    NASA Astrophysics Data System (ADS)

    Max, Jean-Joseph; Chapados, Camille

    2005-01-01

    Acetone and methanol mixtures covering the whole solubility range are studied by Fourier transform infrared attenuated total reflectance spectroscopy. The strong bathochromic shifts observed on methanol OH and acetone CO stretch IR bands are related to hydrogen bonds between these groups. Factor analysis separates the spectra into four acetone and four methanol principal factors. A random molecular model developed for the acetone-water system [Max and Chapados, J. Chem. Phys. 119, 5632 (2003); 120, 6625 (2004)] was modified for the acetone-methanol system. This model, which takes into account H bonds accepted by methanol and acetone, is made up of 12 methanol and 11 acetone species. The 23 species abundances are regrouped according to evolving patterns or spectral similarities to compare them to the eight experimental factors. Methanol acetone mixtures are almost but not exactly random: the methanol oxygen atoms have stronger capacities than acetone to accept H bonds from methanol in the proportion 1.5 to 1. Since oxygen atoms are in excess, all labile hydrogen atoms will form H bonds. As acetone is added to methanol, its OH stretch band blueshifts as the number of accepted H bonds decreases. When methanol gives one H bond and accepts one, an H-bonding network is formed that was coined "chained organization." However, the acetone molecules do not sequester any methanol molecules by breaking or increasing the H-bond methanol network. Similarly, the methanol molecules do not sequester any acetone molecules. Consequently no acetone-methanol complex is formed in the mixtures. Gaussian simulation of the four principal factors in the methanol OH stretch region gave three distinct absorption regimes consisting of the OH stretch bands and their satellites that are identified as MeOH1, MeOH2, and MeOH3 (subscript indicates the number of H, covalent and H bond, which surround the oxygen). These regimes are related to those identified in the water-acetone system as OH2, OH3

  1. Controlling Citrate Synthase Expression by CRISPR/Cas9 Genome Editing for n-Butanol Production in Escherichia coli.

    PubMed

    Heo, Min-Ji; Jung, Hwi-Min; Um, Jaeyong; Lee, Sang-Woo; Oh, Min-Kyu

    2017-02-17

    Genome editing using CRISPR/Cas9 was successfully demonstrated in Esherichia coli to effectively produce n-butanol in a defined medium under microaerobic condition. The butanol synthetic pathway genes including those encoding oxygen-tolerant alcohol dehydrogenase were overexpressed in metabolically engineered E. coli, resulting in 0.82 g/L butanol production. To increase butanol production, carbon flux from acetyl-CoA to citric acid cycle should be redirected to acetoacetyl-CoA. For this purpose, the 5'-untranslated region sequence of gltA encoding citrate synthase was designed using an expression prediction program, UTR designer, and modified using the CRISPR/Cas9 genome editing method to reduce its expression level. E. coli strains with decreased citrate synthase expression produced more butanol and the citrate synthase activity was correlated with butanol production. These results demonstrate that redistributing carbon flux using genome editing is an efficient engineering tool for metabolite overproduction.

  2. Integration of stable isotope and trace contaminant concentration for enhanced forensic acetone discrimination

    SciTech Connect

    Moran, James J.; Ehrhardt, Christopher J.; Wahl, Jon H.; Kreuzer, Helen W.; Wahl, Karen L.

    2013-07-18

    We analyzed 21 neat acetone samples from 15 different suppliers to demonstrate the utility of a coupled stable isotope and trace contaminant strategy for distinguishing forensically-relevant samples. By combining these two pieces of orthogonal data we could discriminate all of the acetones that were produced by the 15 different suppliers. Using stable isotope ratios alone, we were able to distinguish 9 acetone samples, while the remaining 12 fell into four clusters with highly similar signatures. Adding trace chemical contaminant information enhanced discrimination to 13 individual acetones with three residual clusters. The acetones within each cluster shared a common manufacturer and might, therefore, not be expected to be resolved. The data presented here demonstrates the power of combining orthogonal data sets to enhance sample fingerprinting and highlights the role disparate data could play in future forensic investigations.

  3. Detection of acetone processing of castor bean mash for forensic investigation of ricin preparation methods.

    PubMed

    Kreuzer, Helen W; Wahl, Jon H; Metoyer, Candace N; Colburn, Heather A; Wahl, Karen L

    2010-07-01

    Samples containing the toxic castor bean protein ricin have been recently seized in connection with biocriminal activity. Analytical methods that enable investigators to determine how the samples were prepared and to match seized samples to potential source materials are needed. One commonly described crude ricin preparation method is acetone extraction of crushed castor beans. Here, we describe the use of solid-phase microextraction and headspace analysis to determine whether castor beans were processed by acetone extraction. We prepared acetone-extracted castor bean mash, along with controls of unextracted mash and mash extracted with nonacetone organic solvents. Samples of acetone-extracted mash and unextracted mash were stored in closed containers for up to 109 days at both room temperature and -20 degrees C, and in open containers at room temperature for up to 94 days. Acetone-extracted bean mash could consistently be statistically distinguished from controls, even after storage in open containers for 94 days.

  4. Boron nitride nanotube based nanosensor for acetone adsorption: a DFT simulation.

    PubMed

    Ganji, Masoud Darvish; Rezvani, Mahyar

    2013-03-01

    We have investigated the adsorption properties of acetone on zigzag single-walled BNNTs using density functional theory (DFT) calculations. The results obtained show that acetone is strongly bound to the outer surface of a (5,0) BNNT on the top site directly above the boron atom, with a binding energy of -96.16 kJ mol(-1) and a B-O binding distance of 1.654 Å. Our first-principles calculations also predict that the ability of zigzag BNNTs to adsorb acetone is significantly stronger than the corresponding ability of zigzag CNTs. A comparative investigation of BNNTs with different diameters indicated that the ability of the side walls of the tubes to adsorb acetone decreases significantly for nanotubes with larger diameters. Furthermore, the stability of the most stable acetone/BNNT complex was tested using ab initio molecular dynamics simulation at room temperature.

  5. Structure and internal rotation dynamics of the acetone-neon complex studied by microwave spectroscopy

    NASA Astrophysics Data System (ADS)

    Gao, Jiao; Seifert, Nathan A.; Thomas, Javix; Xu, Yunjie; Jäger, Wolfgang

    2016-12-01

    The microwave spectra of the van der Waals complexes acetone-20Ne and acetone-22Ne were measured using a cavity-based supersonic jet Fourier-transform microwave spectrometer in the region from 5 to 18 GHz. For these two isotopologues, both c- and weaker a-type transitions were observed. The transitions are split into multiplets due to the internal rotation of the two methyl groups in acetone. Initial electronic structure calculations were performed at the MP2/6-311++g (2d, p) level of theory and the internal rotation barrier height of the methyl groups was calculated to be ∼2.8 kJ/mol. The ab initio rotational constants were the basis for the spectroscopic searches, but the multiplet structures and floppiness of the complex made the quantum number assignment very difficult. The assignment was finally achieved with the aid of constructing closed frequency loops and predicting internal rotation splittings using the XIAM internal rotation program. The acetone methyl group tunneling barrier height was determined experimentally to be 3.10(6) kJ mol-1 [259(5) cm-1] in the acetone-Ne complex, which is lower than in the acetone monomer but comparable to the acetone-Ar complex (Kang et al., 2002). Experimental data and high-level CCSD(T)/aug-cc-pVTZ calculations suggest that the Ne atom lies directly above the plane formed by the carbonyl group and the two carbon-carbon bonds, which is different than the slightly offset position found previously in the acetone-Ar complex. Additionally, ab initio calculations and Quantum Theory of Atoms in Molecules analyses were used to analyze the methyl internal rotation motions in acetone and acetone-Ne.

  6. Development of a PtSn bimetallic catalyst for direct fuel cells using bio-butanol fuel.

    PubMed

    Puthiyapura, V K; Brett, D J L; Russell, A E; Lin, W F; Hardacre, C

    2015-09-07

    Pt and PtSn catalysts were studied for n-butanol electro-oxidation at various temperatures. PtSn showed a higher activity towards butanol electro-oxidation compared to Pt in acidic media. The onset potential for n-butanol oxidation on PtSn is ∼520 mV lower than that found on Pt, and significantly lower activation energy was found for PtSn compared with that for Pt.

  7. Genome-scale analyses of butanol tolerance in Saccharomyces cerevisiae reveal an essential role of protein degradation

    PubMed Central

    2013-01-01

    Background n-Butanol and isobutanol produced from biomass-derived sugars are promising renewable transport fuels and solvents. Saccharomyces cerevisiae has been engineered for butanol production, but its high butanol sensitivity poses an upper limit to product titers that can be reached by further pathway engineering. A better understanding of the molecular basis of butanol stress and tolerance of S. cerevisiae is important for achieving improved tolerance. Results By combining a screening of the haploid S. cerevisiae knock-out library, gene overexpression, and genome analysis of evolutionary engineered n-butanol-tolerant strains, we established that protein degradation plays an essential role in tolerance. Strains deleted in genes involved in the ubiquitin-proteasome system and in vacuolar degradation of damaged proteins showed hypersensitivity to n-butanol. Overexpression of YLR224W, encoding the subunit responsible for the recognition of damaged proteins of an ubiquitin ligase complex, resulted in a strain with a higher n-butanol tolerance. Two independently evolved n-butanol-tolerant strains carried different mutations in both RPN4 and RTG1, which encode transcription factors involved in the expression of proteasome and peroxisomal genes, respectively. Introduction of these mutated alleles in the reference strain increased butanol tolerance, confirming their relevance in the higher tolerance phenotype. The evolved strains, in addition to n-butanol, were also more tolerant to 2-butanol, isobutanol and 1-propanol, indicating a common molecular basis for sensitivity and tolerance to C3 and C4 alcohols. Conclusions This study shows that maintenance of protein integrity plays an essential role in butanol tolerance and demonstrates new promising targets to engineer S. cerevisiae for improved tolerance. PMID:23552365

  8. Butanol tolerance regulated by a two-component response regulator Slr1037 in photosynthetic Synechocystis sp. PCC 6803

    PubMed Central

    2014-01-01

    Background Butanol production directly from CO2 in photosynthetic cyanobacteria is restricted by the high toxicity of butanol to the hosts. In previous studies, we have found that a few two-component signal transduction systems (TCSTSs) were differentially regulated in Synechocystis sp. PCC 6803 after butanol treatment. Results To explore regulatory mechanisms of butanol tolerance, in this work, by constructing gene knockout mutants of the butanol-responsive TCSTS genes and conducting tolerance analysis, we uncovered that an orphan slr1037 gene encoding a novel response regulator was involved in butanol tolerance in Synechocystis. Interestingly, the ∆slr1037 mutant grew similarly to the wild type under several other stress conditions tested, which suggests that its regulation on butanol tolerance is specific. Using a quantitative iTRAQ LC-MS/MS proteomics approach coupled with real-time reverse transcription PCR, we further determined the possible butanol-tolerance regulon regulated by Slr1037. The results showed that, after slr1037 deletion, proteins involved in photosynthesis and glycolysis/gluconeogenesis of central metabolic processes, and glutaredoxin, peptide methionine sulfoxide reductase and glucosylglycerol-phosphate synthase with stress-responsive functions were down-regulated, suggesting that Slr1037 may exhibit regulation to a wide range of cellular functions in combating butanol stress. Conclusions The study provided a proteomic description of the putative butanol-tolerance regulon regulated by the slr1037 gene. As the first signal transduction protein identified directly related to butanol tolerance, response regulator Slr1037 could be a natural candidate for transcriptional engineering to improve butanol tolerance in Synechocystis. PMID:24932218

  9. Biofuel combustion chemistry: from ethanol to biodiesel.

    PubMed

    Kohse-Höinghaus, Katharina; Osswald, Patrick; Cool, Terrill A; Kasper, Tina; Hansen, Nils; Qi, Fei; Westbrook, Charles K; Westmoreland, Phillip R

    2010-05-10

    Biofuels, such as bio-ethanol, bio-butanol, and biodiesel, are of increasing interest as alternatives to petroleum-based transportation fuels because they offer the long-term promise of fuel-source regenerability and reduced climatic impact. Current discussions emphasize the processes to make such alternative fuels and fuel additives, the compatibility of these substances with current fuel-delivery infrastructure and engine performance, and the competition between biofuel and food production. However, the combustion chemistry of the compounds that constitute typical biofuels, including alcohols, ethers, and esters, has not received similar public attention. Herein we highlight some characteristic aspects of the chemical pathways in the combustion of prototypical representatives of potential biofuels. The discussion focuses on the decomposition and oxidation mechanisms and the formation of undesired, harmful, or toxic emissions, with an emphasis on transportation fuels. New insights into the vastly diverse and complex chemical reaction networks of biofuel combustion are enabled by recent experimental investigations and complementary combustion modeling. Understanding key elements of this chemistry is an important step towards the intelligent selection of next-generation alternative fuels.

  10. Caenorhabditis elegans battling starvation stress: low levels of ethanol prolong lifespan in L1 larvae.

    PubMed

    Castro, Paola V; Khare, Shilpi; Young, Brian D; Clarke, Steven G

    2012-01-01

    The nematode Caenorhabditis elegans arrests development at the first larval stage if food is not present upon hatching. Larvae in this stage provide an excellent model for studying stress responses during development. We found that supplementing starved larvae with ethanol markedly extends their lifespan within this L1 diapause. The effects of ethanol-induced lifespan extension can be observed when the ethanol is added to the medium at any time between 0 and 10 days after hatching. The lowest ethanol concentration that extended lifespan was 1 mM (0.005%); higher concentrations to 68 mM (0.4%) did not result in increased survival. In spite of their extended survival, larvae did not progress to the L2 stage. Supplementing starved cultures with n-propanol and n-butanol also extended lifespan, but methanol and isopropanol had no measurable effect. Mass spectrometry analysis of nematode fatty acids and amino acids revealed that L1 larvae can incorporate atoms from ethanol into both types of molecules. Based on these data, we suggest that ethanol supplementation may extend the lifespan of L1 larvae by either serving as a carbon and energy source and/or by inducing a stress response.

  11. Engineering global transcription factor cyclic AMP receptor protein of Escherichia coli for improved 1-butanol tolerance.

    PubMed

    Zhang, Hongfang; Chong, Huiqing; Ching, Chi Bun; Song, Hao; Jiang, Rongrong

    2012-05-01

    One major challenge in biofuel production, including biobutanol production, is the low tolerance of the microbial host towards increasing biofuel concentration during fermentation. Here, we have demonstrated that Escherichia coli 1-butanol tolerance can be greatly enhanced through random mutagenesis of global transcription factor cyclic AMP receptor protein (CRP). Four mutants (MT1-MT4) with elevated 1-butanol tolerance were isolated from error-prone PCR libraries through an enrichment screening. A DNA shuffling library was then constructed using MT1-MT4 as templates and one mutant (MT5) that exhibited the best tolerance ability among all variants was selected. In the presence of 0.8 % (v/v, 6.5 g/l) 1-butanol, the growth rate of MT5 was found to be 0.28 h(-1) while that of wild type was 0.20 h(-1). When 1-butanol concentration increased to 1.2 % (9.7 g/l), the growth rate of MT5 (0.18 h(-1)) became twice that of the wild type (0.09 h(-1)). Microbial adhesion to hydrocarbon test showed that cell surface of MT5 was less hydrophobic and its cell length became significantly longer in the presence of 1-butanol, as observed by scanning electron microscopy. Quantitative real-time reverse transcription PCR analysis revealed that several CRP regulated, 1-butanol stress response related genes (rpoH, ompF, sodA, manX, male, and marA) demonstrated differential expression in MT5 in the presence or absence of 1-butanol. In conclusion, direct manipulation of the transcript profile through engineering global transcription factor CRP can provide a useful tool in strain engineering.

  12. Metabolic engineering of Klebsiella pneumoniae for the de novo production of 2-butanol as a potential biofuel.

    PubMed

    Chen, Zhen; Wu, Yao; Huang, Jinhai; Liu, Dehua

    2015-12-01

    Butanol isomers are important bulk chemicals and promising fuel substitutes. The inevitable toxicity of n-butanol and isobutanol to microbial cells hinders their final titers. In this study, we attempt to engineer Klebsiella pneumoniae for the de novo production of 2-butanol, another butanol isomer which shows lower toxicity than n-butanol and isobutanol. 2-Butanol synthesis was realized by the extension of the native meso-2,3-butanediol synthesis pathway with the introduction of diol dehydratase and secondary alcohol dehydrogenase. By the screening of different secondary alcohol dehydrogenases and diol dehydratases, 320mg/L of 2-butanol was produced by the best engineered K. pneumoniae. The production was increased to 720mg/L by knocking out the ldhA gene and appropriate addition of coenzyme B12. Further improvement of 2-butanol to 1030mg/L was achieved by protein engineering of diol dehydratase. This work lays the basis for the metabolic engineering of microorganism for the production of 2-butanol as potential biofuel.

  13. Impact of higher alcohols blended in gasoline on light-duty vehicle exhaust emissions.

    PubMed

    Ratcliff, Matthew A; Luecke, Jon; Williams, Aaron; Christensen, Earl; Yanowitz, Janet; Reek, Aaron; McCormick, Robert L

    2013-12-03

    Certification gasoline was splash blended with alcohols to produce four blends: ethanol (16 vol%), n-butanol (17 vol%), i-butanol (21 vol%), and an i-butanol (12 vol%)/ethanol (7 vol%) mixture; these fuels were tested in a 2009 Honda Odyssey (a Tier 2 Bin 5 vehicle) over triplicate LA92 cycles. Emissions of oxides of nitrogen, carbon monoxide, non-methane organic gases (NMOG), unburned alcohols, carbonyls, and C1-C8 hydrocarbons (particularly 1,3-butadiene and benzene) were determined. Large, statistically significant fuel effects on regulated emissions were a 29% reduction in CO from E16 and a 60% increase in formaldehyde emissions from i-butanol, compared to certification gasoline. Ethanol produced the highest unburned alcohol emissions of 1.38 mg/mile ethanol, while butanols produced much lower unburned alcohol emissions (0.17 mg/mile n-butanol, and 0.30 mg/mile i-butanol); these reductions were offset by higher emissions of carbonyls. Formaldehyde, acetaldehyde, and butyraldehyde were the most significant carbonyls from the n-butanol blend, while formaldehyde, acetone, and 2-methylpropanal were the most significant from the i-butanol blend. The 12% i-butanol/7% ethanol blend was designed to produce no increase in gasoline vapor pressure. This fuel's exhaust emissions contained the lowest total oxygenates among the alcohol blends and the lowest NMOG of all fuels tested.

  14. Conditioned Place Preference to Acetone Inhalation and the Effects on Locomotor Behavior and 18FDG Uptake

    SciTech Connect

    Pai, J.C.; Dewey, S.L.; Schiffer, W.; Lee, D.

    2006-01-01

    Acetone is a component in many inhalants that have been widely abused. While other solvents have addictive potential, such as toluene, it is unclear whether acetone alone contains addictive properties. The locomotor, relative glucose metabolism and abusive effects of acetone inhalation were studied in animals using the conditioned place preference (CPP) paradigm and [18F]2-fluorodeoxy-D-glucose (18FDG) imaging. The CPP apparatus contains two distinct conditioning chambers and a middle adaptation chamber, each lined with photocells to monitor locomotor activity. Adolescent Sprague-Dawley rats (n=16; 90-110 g) were paired with acetone in least preferred conditioning chamber, determined on the pretest day. The animals were exposed to a 10,000 ppm dose for an hour, alternating days with air. A CPP test was conducted after the 3rd, 6th and 12th pairing. In these same animals, the relative glucose metabolism effects were determined using positron emission tomography (PET) imaging with 18FDG. Following the 3rd pairing, there was a significant aversion to the acetone paired chamber (190.9 ± 13.7 sec and 241.7 ± 16.9 sec, acetone and air, respectively). After the 6th pairing, there was no significant preference observed with equal time spent in each chamber (222 ± 21 sec and 207 ± 20 sec, acetone and air-paired, respectively). A similar trend was observed after the 12th pairing (213 ± 21 sec and 221 ± 22 sec, acetone and air-paired, respectively). Locomotor analysis indicated a significant decrease (p<0.05) from air pairings to acetone pairings on the first and sixth pairings. The observed locomotor activity was characteristic of central nervous system (CNS) depressants, without showing clear abusive effects in this CPP model. In these studies, acetone vapors were not as reinforcing as other solvents, shown by overall lack of preference for the acetone paired side of the chamber. PET imaging indicated a regionally specific distribution of 18FDG uptake following

  15. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management

    PubMed Central

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-01-01

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no “best-practice method” for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p < 0.05) between the mean individual breath acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T

  16. Formation of halogenated acetones in the lower troposphere

    NASA Astrophysics Data System (ADS)

    Sattler, Tobias; Wittmer, Julian; Krause, Torsten; Schöler, Heinz Friedrich; Kamilli, Katharina; Held, Andreas; Zetzsch, Cornelius; Ofner, Johannes; Atlas, Elliot

    2015-04-01

    Western Australia is a semi-/arid region that is heavily influenced by climate change and agricultural land use. The area is known for its saline lakes with a wide range of hydrogeochemical parameters and consists of ephemeral saline and saline groundwater fed lakes with a pH range from 2.5 to 7.1. In 2012 a novel PTFE-chamber was setup directly on the lakes. The 1.5 m³ cubic chamber was made of UV transparent PTFE foil to permit photochemistry while preventing dilution of the air due to lateral wind transport. This experimental setup allows linking measured data directly to the chemistry of and above the salt lakes. Air samples were taken using stainless steel canisters and measured by GC-MS/ECD. Sediment, crust and water samples were taken for investigation of potential VOC and VOX emissions in the laboratory using GC-MS. Several lakes were investigated and canister samples were taken over the day to see diurnal variations. The first samples were collected at 6 a.m. and from this time every 2 hours a canister was filled with chamber air. Concentrations of chloroacetone up to 15 ppb and of bromoacetone up to 40 ppb in the air samples were detected. The concentrations vary over the day and display their highest values around noon. Soil and water samples showed a variety of highly volatile and semi-volatile VOC/VOX but no halogenated acetones. An abiotic formation of these VOC/VOX seems conclusive due to iron-catalysed reactions below the salt crust [1]. The salt crust is the interface through which VOC/VOX pass from soil/groundwater to the atmosphere where they were photochemically altered. This explains the finding of halo acetones only in the air samples and not in water and soil samples measured in the laboratory. The main forming pathway for these haloacetones is the direct halogenation due to atomic chlorine and bromine above the salt lakes [2]. A minor pathway is the atmospheric degradation of chloropropane and bromopropane [3]. These halopropanes were found

  17. Evaluation of solvent system for the enzymatic synthesis of ethanol-based biodiesel from sludge palm oil (SPO).

    PubMed

    Nasaruddin, Ricca Rahman; Alam, Md Zahangir; Jami, Mohammed Saedi

    2014-02-01

    A green technology of biodiesel production focuses on the use of enzymes as the catalyst. In enzymatic biodiesel synthesis, suitable solvent system is very essential to reduce the inhibition effects of the solvent to the enzymes. This study produced ethanol-based biodiesel from a low-cost sludge palm oil (SPO) using locally-produced Candida cylindracea lipase from fermentation of palm oil mill effluent (POME) based medium. The optimum levels of ethanol-to-SPO molar ratio and enzyme loading were found to be 4:1 and 10 U/25 g of SPO respectively with 54.4% w/w SPO yield of biodiesel and 21.7% conversion of free fatty acid (FFA) into biodiesel. Addition of tert-butanol at 2:1 tert-butanol-to-SPO molar ratio into the ethanol-solvent system increased the yield of biodiesel to 71.6% w/w SPO and conversion of FFA into biodiesel to 28.8%. The SPO and ethanol have promising potential for the production of renewable biodiesel using enzymatic-catalyzed esterification and transesterification.

  18. 40 CFR 721.10238 - Formaldehyde, polymers with acetone-phenol reaction products and phenol, potassium sodium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Formaldehyde, polymers with acetone..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts. (a) Chemical substance..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts (PMN P-09-147; CAS...

  19. Continuous butanol fermentation from xylose with high cell density by cell recycling system.

    PubMed

    Zheng, Jin; Tashiro, Yukihiro; Yoshida, Tsuyoshi; Gao, Ming; Wang, Qunhui; Sonomoto, Kenji

    2013-02-01

    A continuous butanol production system with high-density Clostridium saccharoperbutylacetonicum N1-4 generated by cell recycling was established to examine the characteristics of butanol fermentation from xylose. In continuous culture without cell recycling, cell washout was avoided by maintaining pH>5.6 at a dilution rate of 0.26 h(-1), indicating pH control was critical to this experiment. Subsequently, continuous culture with cell recycling increased cell concentration to 17.4 g L(-1), which increased butanol productivity to 1.20 g L(-1) h(-1) at a dilution rate of 0.26 h(-1) from 0.529 g L(-1) h(-1) without cell recycling. The effect of dilution rates on butanol production was also investigated in continuous culture with cell recycling. Maximum butanol productivity (3.32 g L(-1) h(-1)) was observed at a dilution rate of 0.78 h(-1), approximately 6-fold higher than observed in continuous culture without cell recycling (0.529 g L(-1) h(-1)).

  20. Driving forces enable high-titer anaerobic 1-butanol synthesis in Escherichia coli.

    PubMed

    Shen, Claire R; Lan, Ethan I; Dekishima, Yasumasa; Baez, Antonino; Cho, Kwang Myung; Liao, James C

    2011-05-01

    1-Butanol, an important chemical feedstock and advanced biofuel, is produced by Clostridium species. Various efforts have been made to transfer the clostridial 1-butanol pathway into other microorganisms. However, in contrast to similar compounds, only limited titers of 1-butanol were attained. In this work, we constructed a modified clostridial 1-butanol pathway in Escherichia coli to provide an irreversible reaction catalyzed by trans-enoyl-coenzyme A (CoA) reductase (Ter) and created NADH and acetyl-CoA driving forces to direct the flux. We achieved high-titer (30 g/liter) and high-yield (70 to 88% of the theoretical) production of 1-butanol anaerobically, comparable to or exceeding the levels demonstrated by native producers. Without the NADH and acetyl-CoA driving forces, the Ter reaction alone only achieved about 1/10 the level of production. The engineered host platform also enables the selection of essential enzymes with better catalytic efficiency or expression by anaerobic growth rescue. These results demonstrate the importance of driving forces in the efficient production of nonnative products.

  1. Metabolic engineering of Saccharomyces cerevisiae for the production of isobutanol and 3-methyl-1-butanol.

    PubMed

    Park, Seong-Hee; Kim, Sujin; Hahn, Ji-Sook

    2014-11-01

    Saccharomyces cerevisiae naturally produces small amounts of isobutanol and 3-methyl-1-butanol via Ehrlich pathway from the catabolism of valine and leucine, respectively. In this study, we engineered CEN.PK2-1C, a leucine auxotrophic strain having a LEU2 gene mutation, for the production of isobutanol and 3-methyl-1-butanol. First, ALD6 encoding aldehyde dehydrogenase and BAT1 involved in valine synthesis were deleted to eliminate competing pathways. We also increased transcription of endogenous genes in the valine and leucine biosynthetic pathways by expressing Leu3Δ601, a constitutively active form of Leu3 transcriptional activator. For the production of isobutanol, genes involved in isobutanol production (ILV2, ILV3, ILV5, ARO10, and ADH2) were additionally overexpressed in ald6Δbat1Δ strain expressing LEU3Δ601, resulting in 376.9 mg/L isobutanol production from 100 g/L glucose. To increase 3-methyl-1-butanol production, leucine biosynthetic genes were additionally overexpressed in the final isobutanol-production strain. The resulting strain overexpressing LEU2 and LEU4 (D578Y) , a feedback inhibition-insensitive mutant of LEU4, showed a 34-fold increase in 3-methyl-1-butanol synthesis compared with CEN.PK2-1C control strain, producing 765.7 mg/L 3-methyl-1-butanol.

  2. Stacking structure of confined 1-butanol in SBA-15 investigated by solid-state NMR spectroscopy.

    PubMed

    Lin, Yun-Chih; Chou, Hung-Lung; Sarma, Loka Subramanyam; Hwang, Bing-Joe

    2009-10-12

    Understanding the complex thermodynamic behavior of confined amphiphilic molecules in biological or mesoporous hosts requires detailed knowledge of the stacking structures. Here, we present detailed solid-state NMR spectroscopic investigations on 1-butanol molecules confined in the hydrophilic mesoporous SBA-15 host. A range of NMR spectroscopic measurements comprising of (1)H spin-lattice (T(1)), spin-spin (T(2)) relaxation, (13)C cross-polarization (CP), and (1)H,(1)H two-dimensional nuclear Overhauser enhancement spectroscopy ((1)H,(1)H 2D NOESY) with the magic angle spinning (MAS) technique as well as static wide-line (2)H NMR spectra have been used to investigate the dynamics and to observe the stacking structure of confined 1-butanol in SBA-15. The results suggest that not only the molecular reorientation but also the exchange motions of confined molecules of 1-butanol are extremely restricted in the confined space of the SBA-15 pores. The dynamics of the confined molecules of 1-butanol imply that the (1)H,(1)H 2D NOESY should be an appropriate technique to observe the stacking structure of confined amphiphilc molecules. This study is the first to observe that a significant part of confined 1-butanol molecules are orientated as tilted bilayered structures on the surface of the host SBA-15 pores in a time-average state by solid-state NMR spectroscopy with the (1)H,(1)H 2D NOESY technique.

  3. Fermentation approach for enhancing 1-butanol production using engineered butanologenic Escherichia coli.

    PubMed

    Chen, Shang-Kai; Chin, Wei-Chih; Tsuge, Kenji; Huang, Chieh-Chen; Li, Si-Yu

    2013-10-01

    In this study, engineered butanologenic Escherichia coli T5 constructed by the OGAB method was used for 1-butanol production. The results showed the feasibility of the artificial butanologenic operon, (Promoter Pr)-thil-crt-bcd-etfB-etfA-hbd-adhe1-adhe, where the 1-butanol titer, specific BuOH yield, and BuOH yield were 4.50 mg/L, 4.50 mg-BuOH/g cell, and 0.35 mg-BuOH/g-glucose, respectively. Fermentation conditions of anaerobic, low initial concentrations of carbon sources, low oxidation state of carbon source, pH of 6, addition of glutathione and citrate, had been shown for efficiently improving the 1-butanol production. The premise behind these fermentation approaches can be categorized into two lines of reasoning, either elevated the availability of acetyl-CoA or lowered the intracellular redox state. By comparing the fermentation conditions tested in this study, pH has been shown to be the most efficiency strategies for 1-butanol production while the replacement of glucose with glycerol provides the highest improvement in butanol yield.

  4. Butanol production from acid hydrolyzed corn fiber with Clostridium beijerinckii mutant.

    PubMed

    Du, Teng-fei; He, Ai-yong; Wu, Hao; Chen, Jia-nan; Kong, Xiang-ping; Liu, Jun-li; Jiang, Min; Ouyang, Ping-kai

    2013-05-01

    Sulfuric acid treated corn fiber hydrolysate (SACFH) inhibited cell growth and the production of butanol (4.7±0.2 g/L) by Clostridium beijerinckii IB4 in P2 medium. Optimal medium components were determined using fractional factorial design. NH4HCO3, FeSO4·7H2O and CaCO3 were demonstrated to be significant components in the production of butanol. The Box-Behnken design and a corresponding quadratic model were used to predict medium components (NH4HCO3 1.96 g/L, FeSO4·7H2O 0.26 g/L and CaCO3 3.15 g/L) and butanol yield (9.5 g/L). The confirmation experiment, under the predicted optimal conditions, yielded a butanol level of 9.5±0.1g/L. This study indicates that the Box-Behnken design is an effective approach for screening the optimal medium components required for the production of butanol. It also demonstrates that SACFH, which has high levels of inhibitors such as furan and phenolic compounds, may be used as a renewable carbon source in the production of biofuels.

  5. Heterogeneous photocatalytic oxidation of acetone for airpurification by near UV-irradiated titanium dioxide.

    PubMed

    Chang, Chiu-Ping; Chen, Jong-Nan; Lu, Ming-Chun

    2003-06-01

    This work presents a photocatalysis-based method to treat and purify air because of its broad applicability to common, oxidizable air contaminants. The effect of oxygen content, temperature, water vapor, and acetone concentration on the photooxidation of acetone on TiO2 surface was investigated. The photocatalytic decomposition reaction of acetone obeyed the first-order equation. The decomposition rate increased with increasing the oxygen content. The rate of acetone oxidation increased when water vapor increased from 18.7 to 417 microM and decreased at higher than 417 microM. The conversion and mineralization of acetone decreased at higher than 138 degrees C. The initial rate of acetone degradation can be well described by the Langmuir-Hinshelwood rate form. The specific reaction rate constant and the equilibrium adsorption are 15.8 microM/min and 0.0671 L/microM, respectively. The difference between observed and estimated half-lives became larger when the initial concentration of acetone was increased. It is assumed that the intermediates competed with parent compound so that delayed the half-life. The detection of CO2 production can support this assumption.

  6. Measurement of breath acetone concentrations by selected ion flow tube mass spectrometry in type 2 diabetes.

    PubMed

    Storer, Malina; Dummer, Jack; Lunt, Helen; Scotter, Jenny; McCartin, Fiona; Cook, Julie; Swanney, Maureen; Kendall, Deborah; Logan, Florence; Epton, Michael

    2011-12-01

    Selected ion flow tube-mass spectrometry (SIFT-MS) can measure volatile compounds in breath on-line in real time and has the potential to provide accurate breath tests for a number of inflammatory, infectious and metabolic diseases, including diabetes. Breath concentrations of acetone in type 2 diabetic subjects undertaking a long-term dietary modification programme were studied. Acetone concentrations in the breath of 38 subjects with type 2 diabetes were determined by SIFT-MS. Anthropomorphic measurements, dietary intake and medication use were recorded. Blood was analysed for beta hydroxybutyrate (a ketone body), HbA1c (glycated haemoglobin) and glucose using point-of-care capillary (fingerprick) testing. All subjects were able to undertake breath manoeuvres suitable for analysis. Breath acetone varied between 160 and 862 ppb (median 337 ppb) and was significantly higher in men (median 480 ppb versus 296 ppb, p = 0.01). In this cross-sectional study, no association was observed between breath acetone and either dietary macronutrients or point-of-care capillary blood tests. Breath analysis by SIFT-MS offers a rapid, reproducible and easily performed measurement of acetone concentration in ambulatory patients with type 2 diabetes. The high inter-individual variability in breath acetone concentration may limit its usefulness in cross-sectional studies. Breath acetone may nevertheless be useful for monitoring metabolic changes in longitudinal metabolic studies, in a variety of clinical and research settings.

  7. Concentration of dilute acetone-water solutions using pervaporation

    SciTech Connect

    Hollein, M.E.; Hammond, M.; Slater, C.S. )

    1993-03-01

    The separation of acetone-water mixtures by pervaporation has been studied. Four membranes were evaluated: a silicone composite (SC) membrane, a polydimethylsiloxane (PDMS) membrane, a polymethoxysiloxane (PMS), and a poly-ether-block-polyamide copolymer (PEBA) membrane. The silicone composite membrane exhibited a higher flux and selectivity than any of the other membranes studies. At a feed temperature of 50[degrees]C, a permeate-side pressure of 1 torr, and a feed concentration of 5.0%, the silicone composite membrane had a flux of 1.1 kg/m[sup 2][center dot]h and a selectivity of 50. The effects of temperature and permeate-side pressure on membrane transport were studied using the SC membrane. An increase in temperature increased the flux exponentially, but had little effect on selectivity. An analysis of the data shows that the trend agrees quite well with an Arrhenius-type relationship. As the permeate-side pressure increased, the flux decreased in a sigmoidal fashion over the range evaluated. Selectivity did not change significantly over the lower portion of the pressure range studied. The effect of feed concentration on flux and selectivity was also investigated. 30 refs., 11 figs.

  8. Determination of acetone and methyl ethyl ketone in water

    USGS Publications Warehouse

    Tai, D.Y.

    1978-01-01

    Analytical procedures for the determination of acetone and methyl ethyl ketone in water samples were developed. Concentrations in the milligram-per-liter range were determined by injecting an aqueous sample into the analysis system through an injection port, trapping the organics on Tenax-GC at room temperature, and thermally desorbing the organics into a gas chromatograph with a flame ionization detector for analysis. Concentrations in the microgram-per-liter range were determined by sweeping the headspace vapors over a water sample at 50C, trapping on Tenax-GC, and thermally desorbing the organics into the gas chromatograph. The precision for two operators of the milligram-per-liter concentration procedure, expressed as the coefficient of variation, was generally less than 2 percent for concentrations ranging from 16 to 160 milligrams per liter. The precision from two operators of the microgram-per-liter concentration procedure was between 2 and 4 percent for concentrations of 20 and 60 micrograms per liter. (Woodard-USGS)

  9. Infrared spectroscopy of acetone-water liquid mixtures. I. Factor analysis

    NASA Astrophysics Data System (ADS)

    Max, Jean-Joseph; Chapados, Camille

    2003-09-01

    Acetone and water mixtures covering the whole solubility range were measured by Fourier transform infrared attenuated total reflectance spectroscopy. In this system, only water can supply the hydrogen atoms necessary for hydrogen bonding. Using spectral windowing with factor analysis (FA), 10 principal factors were retrieved, five water and five acetone. Hydrogen bonding is observed on the carbonyl stretch band as water is introduced in the solution, redshifting the band further from its gas position than that observed in pure liquid acetone. This indicates that the hydrogen bonding is stronger than the acetone dipole-dipole interactions because it overrides them. A water molecule isolated in acetone is twice H bonded through its two H atoms; although both OH groups are H-bond donors, the OH stretch band is less redshifted (˜138 cm-1) than that of pure liquid water (˜401 cm-1). This is attributable to the two lone electron pairs remaining on the oxygen atom that sustain a large part of the OH valence bond strength. Hydrogen bonds on the water oxygen weaken both its OH valence bonds and modify the OH stretch band when water is added to the solution. The oxygen atoms of both water and acetone can accept 0, 1, and 2 H bonds given by water to yield three water and three acetone situations. Since these six situations are far less than the 10 principal factors retrieved by FA, other perturbations must be present to account for the difference. Although acetone and water are intermingled through H bonds, hydrates in the sense of an acetone molecule sequestering a number of water molecules or altering the H-bonding water network are not present because the principal factors evolve independently.

  10. Biofuel Ethanol Transport Risk

    EPA Science Inventory

    Ethanol production has increased rapidly over the last 10 years and many communities lack awareness of the increased and growing extent of biofuel transportation through their jurisdictions. These communities and their emergency responders may not have the information and resour...

  11. Process for producing ethanol

    SciTech Connect

    Lantero, O.J.; Fish, J.J.

    1993-07-27

    A process is described for producing ethanol from raw materials containing a high dry solid mash level having fermentable sugars or constituents which can be converted into sugars, comprising the steps of: (a) liquefaction of the raw materials in the presence of an alpha amylase to obtain liquefied mash; (b) saccharification of the liquefied mash in the presence of a glucoamylase to obtain hydrolysed starch and sugars; (c) fermentation of the hydrolysed starch and sugars by yeast to obtain ethanol; and (d) recovering the obtained ethanol, wherein an acid fungal protease is introduced to the liquefied mash during the saccharification and/or to the hydrolysed starch and sugars during the fermentation, thereby increasing the rate of production of ethanol as compared to a substantially similar process conducted without the introduction of the protease.

  12. Ethanol production from lignocellulose

    DOEpatents

    Ingram, Lonnie O.; Wood, Brent E.

    2001-01-01

    This invention presents a method of improving enzymatic degradation of lignocellulose, as in the production of ethanol from lignocellulosic material, through the use of ultrasonic treatment. The invention shows that ultrasonic treatment reduces cellulase requirements by 1/3 to 1/2. With the cost of enzymes being a major problem in the cost-effective production of ethanol from lignocellulosic material, this invention presents a significant improvement over presently available methods.

  13. Drive cycle analysis of butanol/diesel blends in a light-duty vehicle.

    SciTech Connect

    Miers, S. A.; Carlson, R. W.; McConnell, S. S.; Ng, H. K.; Wallner, T.; LeFeber, J.; Energy Systems; Esper Images Video & Multimedia

    2008-10-01

    The potential exists to displace a portion of the petroleum diesel demand with butanol and positively impact engine-out particulate matter. As a preliminary investigation, 20% and 40% by volume blends of butanol with ultra low sulfur diesel fuel were operated in a 1999 Mercedes Benz C220 turbo diesel vehicle (Euro III compliant). Cold and hot start urban as well as highway drive cycle tests were performed for the two blends of butanol and compared to diesel fuel. In addition, 35 MPH and 55 MPH steady-state tests were conducted under varying road loads for the two fuel blends. Exhaust gas emissions, fuel consumption, and intake and exhaust temperatures were acquired for each test condition. Filter smoke numbers were also acquired during the steady-state tests.

  14. Synthesis of butenes through 2-butanol dehydration over mesoporous materials produced from ferrierite

    SciTech Connect

    Jeong, Soyeon; Kim, Hyeonjoo; Bae, Jung A.; Kim, Do Heui; Peden, Charles HF; Park, Young-Kwon; Jeon, Jong Ki

    2012-05-20

    Mesoporous materials synthesized from commercial ferrierite (MMZ-FER) were applied to butanol dehydration. The MMZ-FER was produced by disassembling ferrierite into unit structures in the presence of an alkali solution, adding a surfactant as a templating material, followed by hydrothermal treatment. The effect of the alkali/(Si+Al) ratio in the disassembling step on the characteristics of the catalyst and butanol dehydration performance were investigated. The MMZ-FER materials, synthesized in a condition in which the NaOH/(Si + Al) mole ratio in the disassembling step was 0.67 and 1.0, demonstrated similar textural properties to those of MCM-41. Many weak acid sites developed on the MMZ-FER(0.67) and MMZ-FER(1.0) samples, which is attributed to the creation of ferrierite-induced acid sites. The MMZ-FER materials showed excellent catalytic activity, selectivity, and stability during the dehydration of 2-butanol.

  15. [Particulate distribution characteristics of Chinese phrase V diesel engine based on butanol-diesel blends].

    PubMed

    Lou, Di-Ming; Xu, Ning; Fan, Wen-Jia; Zhang, Tao

    2014-02-01

    With a common rail diesel engine without any modification and the engine exhaust particle number and particle size analyzer EEPS, this study used the air-fuel ratio to investigate the particulate number concentration, mass concentration and number distribution characteristics of a diesel engine fueled with butanol-diesel blends (Bu10, Bu15, Bu20, Bu30 and Bu40) and petroleum diesel. The results show: for all test fuels, the particle number distributions turn to be unimodal. With the increasing of butanol, numbers of nucleation mode particles and small accumulation mode particle decrease. At low speed and low load conditions, the number of large accumulation mode particle increases slightly, but under higher speed and load conditions, the number does not increase. When the fuels contain butanol, the total particle number concentration and mass concentration in all conditions decrease and that is more obvious at high speed load.

  16. Comparison studies of surface cleaning methods for PAN-based carbon fibers with acetone, supercritical acetone and subcritical alkali aqueous solutions

    NASA Astrophysics Data System (ADS)

    Meng, Linghui; Fan, Dapeng; Huang, Yudong; Jiang, Zaixing; Zhang, Chunhua

    2012-11-01

    Four kinds of polyacrylonitrile-based carbon fibers were cleaned by three methods and were characterized by X-ray photoelectron spectroscopy, monofilament tensile strength test and atomic force microscopy (AFM). Experimental results of these tests reveal that the method using supercritical acetone or subcritical potassium hydroxide aqueous solution act as the processing medium shows a better cleaning effect compared to the traditional method, Soxhlet extraction with acetone. The method using supercritical acetone is more appropriate to wipe off the oxygenated contaminants on carbon fibers' surfaces and causes a relatively smaller damage to the bulk strength of each carbon fiber. As far as treating method using the subcritical alkali aqueous solution, it can thoroughly remove silicious contaminants on the surfaces of treated fibers.

  17. Transcriptional Analysis of Lactobacillus brevis to N-Butanol and Ferulic Acid Stress Responses

    PubMed Central

    Winkler, James; Kao, Katy C.

    2011-01-01

    Background The presence of anti-microbial phenolic compounds, such as the model compound ferulic acid, in biomass hydrolysates pose significant challenges to the widespread use of biomass in conjunction with whole cell biocatalysis or fermentation. Currently, these inhibitory compounds must be removed through additional downstream processing or sufficiently diluted to create environments suitable for most industrially important microbial strains. Simultaneously, product toxicity must also be overcome to allow for efficient production of next generation biofuels such as n-butanol, isopropanol, and others from these low cost feedstocks. Methodology and Principal Findings This study explores the high ferulic acid and n-butanol tolerance in Lactobacillus brevis, a lactic acid bacterium often found in fermentation processes, by global transcriptional response analysis. The transcriptional profile of L. brevis reveals that the presence of ferulic acid triggers the expression of currently uncharacterized membrane proteins, possibly in an effort to counteract ferulic acid induced changes in membrane fluidity and ion leakage. In contrast to the ferulic acid stress response, n-butanol challenges to growing cultures primarily induce genes within the fatty acid synthesis pathway and reduced the proportion of 19∶1 cyclopropane fatty acid within the L. brevis membrane. Both inhibitors also triggered generalized stress responses. Separate attempts to alter flux through the Escherichia coli fatty acid synthesis by overexpressing acetyl-CoA carboxylase subunits and deleting cyclopropane fatty acid synthase (cfa) both failed to improve n-butanol tolerance in E. coli, indicating that additional components of the stress response are required to confer n-butanol resistance. Conclusions Several promising routes for understanding both ferulic acid and n-butanol tolerance have been identified from L. brevis gene expression data. These insights may be used to guide further engineering of

  18. Ethanol production from syngas by Clostridium strain P11 using corn steep liquor as a nutrient replacement to yeast extract.

    PubMed

    Maddipati, Prasanth; Atiyeh, Hasan K; Bellmer, Danielle D; Huhnke, Raymond L

    2011-06-01

    The feasibility of replacing yeast extract (YE) by corn steep liquor (CSL), a low cost nutrient source, for syngas fermentation to produce ethanol using Clostridium strain P11 was investigated. About 32% more ethanol (1.7 g L(-1)) was produced with 20 g L(-1) CSL media in 250-mL bottle fermentations compared to media with 1 g L(-1) YE after 360 h. Maximum ethanol concentrations after 360 h of fermentation in a 7.5-L fermentor with 10 and 20 g L(-1) CSL media were 8.6 and 9.6 g L(-1), respectively, which represent 57% and 60% of the theoretical ethanol yields from CO. Only about 6.1 g L(-1) of ethanol was obtained in the medium with 1 g L(-1) YE after 360 h, which represents 53% of the theoretical ethanol yield from CO. The use of CSL also enhanced butanol production by sevenfold compared to YE in bottle fermentations. These results demonstrate that CSL can replace YE as the primary medium component and significantly enhance ethanol production by Clostridium strain P11.

  19. 76 FR 57033 - Draft Toxicological Review of n-Butanol: In Support of Summary Information on the Integrated Risk...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-15

    ... ``Toxicological Review of n-Butanol: In Support of Summary Information on the Integrated Risk Information System... AGENCY Draft Toxicological Review of n-Butanol: In Support of Summary Information on the Integrated Risk Information System (IRIS) AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of Public...

  20. 76 FR 54227 - Draft Toxicological Review of n-Butanol: In Support of Summary Information on the Integrated Risk...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-31

    ...-Butanol: In Support of Summary Information on the Integrated Risk Information System (IRIS)'' (EPA/ 635/R... Integrated Risk Information System (IRIS)'' is available primarily via the Internet on the NCEA home page... AGENCY Draft Toxicological Review of n-Butanol: In Support of Summary Information on the Integrated...