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Sample records for acetone-butanol fermentation revisited

  1. Acetone-butanol Fermentation of Marine Macroalgae

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Acetone-butanol fermentation in Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Tantawi, M.

    1984-10-01

    Acetone and butanol can be produced by anaerobic fermentation of molasses with microorganisms such as Clostridium saccharobutylicum and Clostridium acetobutylicum. There are many steps in the process and the main problem is that the yields are quite susceptible to contamination. At the present time the process is uneconomical due to the cost of molasses, the considerable steam consumption for the sterilizing process and the expense of the disposal of the slops.

  3. System-level modeling of acetone-butanol-ethanol fermentation.

    Science.gov (United States)

    Liao, Chen; Seo, Seung-Oh; Lu, Ting

    2016-05-01

    Acetone-butanol-ethanol (ABE) fermentation is a metabolic process of clostridia that produces bio-based solvents including butanol. It is enabled by an underlying metabolic reaction network and modulated by cellular gene regulation and environmental cues. Mathematical modeling has served as a valuable strategy to facilitate the understanding, characterization and optimization of this process. In this review, we highlight recent advances in system-level, quantitative modeling of ABE fermentation. We begin with an overview of integrative processes underlying the fermentation. Next we survey modeling efforts including early simple models, models with a systematic metabolic description, and those incorporating metabolism through simple gene regulation. Particular focus is given to a recent system-level model that integrates the metabolic reactions, gene regulation and environmental cues. We conclude by discussing the remaining challenges and future directions towards predictive understanding of ABE fermentation. PMID:27020410

  4. Bioreactors and in situ product recovery techniques for acetone-butanol-ethanol fermentation.

    Science.gov (United States)

    Li, Si-Yu; Chiang, Chung-Jen; Tseng, I-Ting; He, Chi-Ruei; Chao, Yun-Peng

    2016-07-01

    The microbial fermentation process is one of the sustainable and environment-friendly ways to produce 1-butanol and other bio-based chemicals. The success of the fermentation process greatly relies on the choice of bioreactors and the separation methods. In this review, the history and the performance of bioreactors for the acetone-butanol-ethanol (ABE) fermentation is discussed. The subject is then focused on in situ product recovery (ISPR) techniques, particularly for the integrated extraction-gas stripping. The usefulness of this promising hybrid ISPR device is acknowledged by its incorporation with batch, fed-batch and continuous processes to improve the performance of ABE fermentation. PMID:27190167

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

    Energy Technology Data Exchange (ETDEWEB)

    Vrana, D.L.; Meagher, M.M.; Hutkins, R.W.; Duffield, B. (Univ. of Nebraska, Lincoln, NE (United States))

    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.

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

    Science.gov (United States)

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

    2015-07-01

    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. PMID:26100881

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

    Science.gov (United States)

    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. PMID:26562687

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:25966390

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  14. 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.

    Science.gov (United States)

    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. PMID:27010341

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

    Science.gov (United States)

    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. PMID:26476171

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:27142628

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

    Science.gov (United States)

    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. PMID:27060246

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

    Science.gov (United States)

    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 ...

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

    Science.gov (United States)

    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. PMID:27005413

  1. The Effect of pH Control on Acetone-Butanol-Ethanol Fermentation by Clostridium acetobutylicum ATCC 824 with Xylose and D-Glucose and D-Xylose Mixture

    Institute of Scientific and Technical Information of China (English)

    Wei Jiang; Zhiqiang Wen; Mianbin Wu; Hong Li; Jun Yang; Jianping Lin; Yijun Lin; Lirong Yang; Peilin Cen

    2014-01-01

    D-Glucose, L-arabinose, D-mannose, D-xylose, and cellobiose are saccharification products of lignocellulose and important carbon sources for industrial fermentation. The fermentation efficiency with each of the five sugars and the mixture of the two most dominant sugars, D-glucose and D-xylose, was evaluated for acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum ATCC 824. The utilization efficacy of the five reducing sugars was in the order of D-glucose, L-arabinose, D-mannose, D-xylose and cellobiose. D-Xylose, the second most abundant component in lignocellulosic hydrolysate, was used in the fermentation either as sole carbon source or mixed with glucose. The results indicated that maintaining pH at 4.8, the optimal pH value for solventogenesis, could increase D-xylose consumption when it was the sole carbon source. Different media con-taining D-glucose and D-xylose at different ratios (1:2, 1:5, 1.5:1, 2:1) were then attempted for the ABE fermenta-tion. When pH was at 4.8 and xylose concentration was five times that of glucose, a 256.9%increase in xylose utilization and 263.7%increase in solvent production were obtained compared to those without pH control. These results demonstrate a possible approach combining optimized pH control and D-glucose and D-xylose ratio to increase the fermentation efficiency of lignocellulosic hydrolysate.

  2. Acetone-butanol-ethanol fermentation from cane molasses by Clostridium beijerinckii DSM 6422%一株拜氏梭菌利用甘蔗废糖蜜发酵生产丙酮丁醇

    Institute of Scientific and Technical Information of China (English)

    孙珊; 汪维云; 倪晔; 王云; 宋钢; 孙志浩

    2012-01-01

    以甘蔗废糖蜜作为原料,利用Clostridium beijerinckii DSM 6422菌株进行丙酮丁醇发酵的初步研究.结果表明:采用H2SO4预处理糖蜜,初糖质量浓度60 g/L,(NH4)2SO4 2g/L,CaCO3 10 g/L,温度30℃,pH 5.5~7.0,接种量6%(体积分数),在5L发酵罐中发酵培养96 h,总溶剂产量为16.17 g/L,其中丁醇质量浓度为10.07 g/L,总溶剂产率为30.2%,糖利用率为89.3%.%Acetone-butanol-ethanol fermentation using sugar cane molasses by Clostridium beijerinckii DSM 6422 was studied. The molasses were pretreated with H2SO4 and the fermentation conditions including carbon source, nitrogen source, temperature and pH, etc. , were optimized. The results showed that the optimal fermentation conditions was as follows; initial sugar concentration 60 g/L, (NH4)2SO4 2 g/L, CaCO3 10 g/L, inoculation amount 6% ( V/V), pH 5. 5-7. 0, fermented at 30 ℃, for 96 h. Under these conditions, the total solvent, butanol ratio, solvent productivity, and sugar utilization in the 5-L bioreac-tor were 16. 17 g/L, 10. 07 g/L, 30. 2% , and 89. 3%, respectively.

  3. Production of Solvent (acetone-butanol-ethanol) in Continuous Fermentation by Clostridium saccharobutylicum DSM 13864 Using Gelatinised Sago Starch as a Carbon Source

    OpenAIRE

    Liew, S. T.; Arbakariya, A.; Rosfarizan, M.; Raha, A. R.

    2006-01-01

    Solvent production by Clostridium saccharobutylicum DSM 13864 was carried out in a single stage continuous culture using 2 L stirred tank fermenter with gelatinised sago starch as a carbon source. From the study it was found that the condition could be adjusted to suit for acids production (high dilution rate and high pH) or solvent production (low dilution rate and low pH) by manipulating the dilution rate and culture pH of single stage continuous fermentation. The highest solvent concentrat...

  4. Recent trends in acetone, butanol, and ethanol (ABE production

    Directory of Open Access Journals (Sweden)

    Keikhosro Karim

    2015-12-01

    Full Text Available Among the renewable fuels considered as a suitable substitute to petroleum-based gasoline, butanol has attracted a great deal of attention due to its unique properties. Acetone, butanol, and ethanol (ABE can be produced biologically from different substrates, including sugars, starch, lignocelluloses, and algae. This process was among the very first biofuel production processes which was commercialized during the First World War. The present review paper discusses the different aspects of the ABE process and the recent progresses made. Moreover, the microorganisms and the biochemistry of the ABE fermentation as well as the feedstocks used are reviewed. Finally, the challenges faced such as low products concentration and products` inhibitory effects on the fermentation are explained and different possible solutions are presented and reviewed.

  5. Production of Solvent (acetone-butanol-ethanol in Continuous Fermentation by Clostridium saccharobutylicum DSM 13864 Using Gelatinised Sago Starch as a Carbon Source

    Directory of Open Access Journals (Sweden)

    Liew, S. T.

    2006-01-01

    Full Text Available Solvent production by Clostridium saccharobutylicum DSM 13864 was carried out in a single stage continuous culture using 2 L stirred tank fermenter with gelatinised sago starch as a carbon source. From the study it was found that the condition could be adjusted to suit for acids production (high dilution rate and high pH or solvent production (low dilution rate and low pH by manipulating the dilution rate and culture pH of single stage continuous fermentation. The highest solvent concentration in outflow (9.10 g/L was obtained at pH 4.5 and dilution rate of 0.05 h^1, which corresponds to overall productivity of 0.46 g/L.h. However, the highest total solvent productivity (0.85 g/L.h was obtained at dilution rate of 0.11 h-1 and pH 4.5, which gave a total solvent yield of 0.29 g solvent/g sago starch. Although the total solvent productivity was greatly increased in continuous culture, the final solvent concentration attained in outflow was decreased by about 53% as compared to batch culture.

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

    Science.gov (United States)

    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. PMID:26718336

  7. 基于果糖与葡萄糖不同混合比例的丙酮丁醇发酵%Acetone-butanol-ethanol fermentation using mixture of glucose and fructose with different portions

    Institute of Scientific and Technical Information of China (English)

    吴又多; 付友思; 齐高相; 陈丽杰; 白凤武

    2014-01-01

    介绍了以不同底物的丁醇发酵结果,阐述了在以55g/L葡萄糖与果糖(1∶4)混合糖模拟菊芋物料为底物的丁醇发酵过程中存在果糖利用及丁醇产量较低等问题,研究了基于葡萄糖与果糖不同混合比例(1∶2、2∶3、3∶2及3∶1)的丁醇发酵性能。研究结果说明了随着混合比例提高,发酵时间由76h缩短至48h,菌体最大生物量OD620由2.1提高至4.3,而当葡萄糖与果糖混合比例为1∶2时,发酵过程中菌体细胞对果糖代谢能力最佳,且终点残糖浓度仅为2.1g/L,果糖利用效率达到95.03%,丁醇及总溶剂产量分别达到9.7g/L与16.0g/L。%Batch acetone-butanol-ethanol (ABE) fermentations from various substrates were briefly introduced. Limiting factors,such as low fructose utilization and butanol production,were involved in batch ABE fermentation by Clostridium acetobutylicum using 55 g/L mixture of glucose and fructose (1∶4) as substrates to stimulate the hydrolysate of Jerusalem artichoke tubers. Then the effect of fructose and glucose with different portions(1∶4 to 1∶2,2∶3,3∶2 and 3∶1)on the performance of batch ABE fermentation was studied. The results showed that the fermentation time was shortened from 76 h to 48 h as the portion increased,and the cell growth with the max OD620 was enhanced from 2.1 to 4.3. The fermentation gave the best metabolic activity of fructose utilization with the glucose/fructose portion of 1∶2,correspondingly,9.7 g/L and 16.0 g/L production of butanol and ABE were produced with only 2.1 g/L residual sugars,resulting in improved fructose utilization efficiency as high as 95.03%.

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

    Science.gov (United States)

    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.

  9. Acetone-butanol fermentation from the mixture of fructose and glucose%果糖及葡萄糖混合物为底物的丙酮丁醇发酵

    Institute of Scientific and Technical Information of China (English)

    邓攀; 陈丽杰; 辛程勋; 白凤武

    2011-01-01

    旨在以果糖和葡萄糖混合物模拟能源作物菊芋块茎水解液发酵生产丁醇.在培养基初始pH 5.5,发酵过程不控制pH的混合糖发酵中,出现了发酵提前终止现象,终点残糖浓度达23.26 g/L,而丁醇产量仅5.51g/L.进一步对比混合糖及葡萄糖、果糖不控制pH的发酵结果表明,导致这一现象的原因可能是有机酸毒性太大和pH太低.全程控制pH的混合糖发酵结果表明,高pH条件有利于提高糖利用率,但产酸多,丁醇产量较低:而低pH条件下发酵残糖较多,但丁醇产量相对较高.基于此,文中采用阶段性pH调控策略,即将发酵初期的pH控制在5.5,待菌体0D620上升到1.0后,解除pH控制,发酵终点残糖浓度下降到2.05 g/L,丁醇产量也相应提高到10.48 g/L.%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 S.S 1 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 S.S 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 2.0S g/L sugars unconverted and 10.48 g

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

    Science.gov (United States)

    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.

  11. Barley Distillers Dried Grains with Solubles (DDGS) as Feedstock for Production of Acetone, Butanol and Ethanol

    NARCIS (Netherlands)

    Houweling-Tan, G.B.N.; Sperber, B.L.H.M.; Wal, van der H.; Bakker, R.R.C.; Lopez Contreras, A.M.

    2016-01-01

    Distillers dried grains with solubles (DDGS) represent important co-product from commercial yeast fermentations, including bioethanol, from grains. In view of the current expansion of the bioethanol fermentation process, with the concomitant increase in production of DDGS, alternative applications t

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

    Science.gov (United States)

    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. PMID:26928043

  13. Butanol production by fermentation: efficient bioreactors

    Science.gov (United States)

    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...

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

    NARCIS (Netherlands)

    Izak, P.; Schwarz, K.M.; Ruth, W.; Bahl, H.; Kragl, U.

    2008-01-01

    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 meas

  15. One hundred years of clostridial butanol fermentation.

    Science.gov (United States)

    Moon, Hyeon Gi; Jang, Yu-Sin; Cho, Changhee; Lee, Joungmin; Binkley, Robert; Lee, Sang Yup

    2016-02-01

    Butanol has been widely used as an important industrial solvent and feedstock for chemical production. Also, its superior fuel properties compared with ethanol make butanol a good substitute for gasoline. Butanol can be efficiently produced by the genus Clostridium through the acetone-butanol-ethanol (ABE) fermentation, one of the oldest industrial fermentation processes. Butanol production via industrial fermentation has recently gained renewed interests as a potential solution to increasing pressure of climate change and environmental problems by moving away from fossil fuel consumption and moving toward renewable raw materials. Great advances over the last 100 years are now reviving interest in bio-based butanol production. However, several challenges to industrial production of butanol still need to be overcome, such as overall cost competitiveness and development of higher performance strains with greater butanol tolerance. This minireview revisits the past 100 years of remarkable achievements made in fermentation technologies, product recovery processes, and strain development in clostridial butanol fermentation through overcoming major technical hurdles. PMID:26738754

  16. Response surface optimisation for acetone-butanol-ethanol production from cassava starch by co-culture of Clostridium butylicum and Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Benjamas Cheirsilp

    2011-11-01

    Full Text Available Acetone-butanol-ethanol (ABE production from cassava starch was enhanced by a syntrophic co-culture of Clostridium butylicum TISTR 1032 and high amylase producing Bacillus subtilis WD 161 without anaerobic pretreatment. The production of amylase and ABE using this co-culture were respectively 16 and 6 times higher than those using the pure culture of C. butylicum TISTR 1032. The effect of the medium components on the performance of the co-culture was investigated using response surface methodology (RSM. Among the investigated components, cassava starch and ammonium nitrate contributed a significant effect on the production of amylase and ABE, while yeast extract had less effect. Based on the optimum strategy using RSM, the ABE production by the co-culture was improved 2.2-fold compared with that obtained from the initial condition and with a minimum requirement of nitrogen source.

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

    Science.gov (United States)

    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.

  18. BUTANOL PRODUCTION BY FERMENTATION OF RENEWABLE FEEDSTOCKS

    OpenAIRE

    Raganati, Francesca

    2014-01-01

    The study carried out during the present Ph.D. program aimed at investigating the Acetone-Butanol-Ethanol (ABE) production process by fermentation. The work was carried out at the Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale of the University of Naples ‘Federico II’. The activities were articulated according to three paths: i) the characterization of the ABE fermentation process as regards kinetics and yields using different renewable resources (lignocellul...

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

    Science.gov (United States)

    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...

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

    OpenAIRE

    Verberkmoes Nathan C; Hettich Robert L; Shah Manesh; Raghavan Vijaya GS; Sivagnanam Kumaran; Lefsrud Mark G

    2011-01-01

    Abstract 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 identifie...

  1. 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

    Science.gov (United States)

    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...

  2. 高掺比ABE/柴油混合燃料的喷雾与燃烧特性%Spray and Combustion Characteristics of Acetone-Butanol-Ethanol (ABE)-Diesel Blend with High ABE Ratio

    Institute of Scientific and Technical Information of China (English)

    吴晗; 林亦律; 肖国炜; Lee Timothy; 李佳峰; 张春化

    2016-01-01

    The acetone-butanol-ethanol(ABE)/diesel blend with high ABE ratio as alternative fuel was studied and the experiments were conducted in a pre-combustion type constant volume chamber.ABE solution with typical volu-metric ratios of 30%, acetone,60%, butanol,and 10%, ethanol was blended with diesel at 80%, volume and was tested.The ambient temperature was set to be 1,100,K and 900,K,which represent normal temperature combustion mode and low temperature combustion mode,respectively,andthe ambient oxygen concentrations were set to be 21%,,16%, and 11%,,respectively,which represent different EGR conditions for diesel engine.In-cylinder pres-sure was recorded by using a pressure transducer and the time-resolved Mie-scattering image and natural flame lumi-nosity were captured by using a high-speed camera coupled with a copper vapor laser as a light source.The results show that,due to the high percentage of ABE in the blend,the liquid penetration and intensity of natural flame lu-minosity are reduced significantly,which indicates a high potential to reduce soot level when it is used as an alterna-tive fuel for internal combustion engine.Furthermore,a soot-free combustion is achieved by combing the low tem-perature combustion with blended fuel with a high percentage of ABE.Hence,in terms of soot emission,high ABE ratio blends are a very promising alternative fuel which can be directly used in diesel engines.%针对丙酮-丁醇-乙醇(ABE)/柴油混合燃料的喷雾蒸发和燃烧过程展开了试验研究.试验在预燃加热式定容燃烧弹中进行,燃料为体积分数80%的ABE和20%,的柴油混合物,且ABE溶液中丙酮、丁醇、乙醇的体积分数分别为30%,、60%,和10%,.试验过程中燃烧弹内喷雾环境温度分别控制在1,100,K和900,K以代表普通燃烧模式和低温燃烧模式,环境氧体积分数分别控制在21%,、16%,和11%,以对应发动机不同的 EGR 工况.由高速摄相机配合激光束的使用,拍摄喷雾

  3. 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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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. PMID:26849199

  5. Biotechnology for producing fuels and chemicals from biomass. Volume 2: Fermentation chemicals from biomass

    Science.gov (United States)

    Villet, R.

    1981-02-01

    The technological and economic feasibility of producing chemicals by fermentation is discussed: acetone; butanol; acetic acid; citric acid; 2,3-butanediol, and propionic acid. Improved cost of fermentative production will hinge on improving yields and using cellulosic feedstocks. The market for acetic acid is likely to grow 5 percent to 7 percent/yr. A potential process for production is the fermentation of hydrolyzed cellulosic material to ethanol followed by chemical conversion to acetic acid. The feedstock cost is 15 to 20 percent of the overall cost of production. The anticipated 5 percent growth in demand for citric acid could be enhanced by using it to displace phosphates in detergent manufacture. A number of useful chemicals can be derived from 2,3-butanediol, which has not been produced commercially on a large scale. The commercial fermentative production of propionic acid has not yet been developed.

  6. Production of biofuels from pretreated microalgae biomass by anaerobic fermentation with immobilized Clostridium acetobutylicum cells.

    Science.gov (United States)

    Efremenko, E N; Nikolskaya, A B; Lyagin, I V; Senko, O V; Makhlis, T A; Stepanov, N A; Maslova, O V; Mamedova, F; Varfolomeev, S D

    2012-06-01

    The purpose of this work was to study the possible use of pretreated biomass of various microalgae and cyanobacteria as substrates for acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum cells immobilized into poly(vinyl alcohol) cryogel. To this end, the biochemical composition of photosynthetic microorganisms cultivated under various conditions was studied. The most efficient technique for pretreating microalgal biomass for its subsequent conversion into biofuels appeared to be thermal decomposition at 108 °C. For the first time the maximum productivity of the ABE fermentation in terms of hydrogen (8.5 mmol/L medium/day) was obtained using pretreated biomass of Nannochloropsis sp. Maximum yields of butanol and ethanol were observed with Arthrospira platensis biomass used as the substrate. Immobilized Clostridium cells were demonstrated to be suitable for multiple reuses (for a minimum of five cycles) in ABE fermentation for producing biofuels from pretreated microalgal biomass.

  7. Biotechnology for producing fuels and chemicals from biomass. Volume II. Fermentation chemicals from biomass

    Energy Technology Data Exchange (ETDEWEB)

    Villet, R. (ed.)

    1981-02-01

    The technological and economic feasibility of producing some selected chemicals by fermentation is discussed: acetone, butanol, acetic acid, citric acid, 2,3-butanediol, and propionic acid. The demand for acetone and butanol has grown considerably. They have not been produced fermentatively for three decades, but instead by the oxo and aldol processes. Improved cost of fermentative production will hinge on improving yields and using cellulosic feedstocks. The market for acetic acid is likely to grow 5% to 7%/yr. A potential process for production is the fermentation of hydrolyzed cellulosic material to ethanol followed by chemical conversion to acetic acid. For about 50 years fermentation has been the chief process for citric acid production. The feedstock cost is 15% to 20% of the overall cost of production. The anticipated 5%/yr growth in demand for citric acid could be enhanced by using it to displace phosphates in detergent manufacture. A number of useful chemicals can be derived from 2,3-butanediol, which has not been produced commercially on a large scale. R and D are needed to establish a viable commercial process. The commercial fermentative production of propionic acid has not yet been developed. Recovery and purification of the product require considerable improvement. Other chemicals such as lactic acid, isopropanol, maleic anhydride, fumarate, and glycerol merit evaluation for commercial fermentative production in the near future.

  8. Butanol production from cane molasses by Clostridium saccharobutylicum DSM 13864: batch and semicontinuous fermentation.

    Science.gov (United States)

    Ni, Ye; Wang, Yun; Sun, Zhihao

    2012-04-01

    Clostridium acetobutylicum strains used in most Chinese ABE (acetone-butanol-ethanol) plants favorably ferment starchy materials like corn, cassava, etc., rather than sugar materials. This is one major problem of ABE industry in China and significantly limits the exploitation of cheap waste sugar materials. In this work, cane molasses were utilized as substrate in ABE production by Clostridium saccharobutylicum DSM 13864. Under optimum conditions, total solvent of 19.80 g/L (13.40 g/L butanol) was reached after 72 h of fermentation in an Erlenmeyer flask. In a 5-L bioreactor, total solvent of 17.88 g/L was attained after 36 h of fermentation, and the productivity and yield were 0.50 g/L/h and 0.33 g ABE/g sugar consumption, respectively. To further enhance the productivity, a two-stage semicontinuous fermentation process was steadily operated for over 8 days (205 h, 26 cycles) with average productivity (stage II) of 1.05 g/L/h and cell concentration (stage I) of 7.43 OD(660), respectively. The average batch fermentation time (stage I and II) was reduced to 21-25 h with average solvent of 15.27 g/L. This study provides valuable process data for the development of industrial ABE fermentation process using cane molasses as substrate. PMID:22362519

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

    Science.gov (United States)

    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.

  10. Industrial production of acetone and butanol by fermentation-100 years later.

    Science.gov (United States)

    Sauer, Michael

    2016-07-01

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:27367813

  13. Improving butanol fermentation to enter the advanced biofuel market.

    Science.gov (United States)

    Tracy, Bryan P

    2012-01-01

    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

  14. Use of Cupriavidus basilensis-aided bioabatement to enhance fermentation of acid-pretreated biomass hydrolysates by Clostridium beijerinckii.

    Science.gov (United States)

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

    2016-09-01

    Lignocellulose-derived microbial inhibitors (LDMICs) prevent efficient fermentation of Miscanthus giganteus (MG) hydrolysates to fuels and chemicals. To address this problem, we explored detoxification of pretreated MG biomass by Cupriavidus basilensis ATCC(®)BAA-699 prior to enzymatic saccharification. We document three key findings from our test of this strategy to alleviate LDMIC-mediated toxicity on Clostridium beijerinckii NCIMB 8052 during fermentation of MG hydrolysates. First, we demonstrate that growth of C. basilensis is possible on furfural, 5-hydroxymethyfurfural, cinnamaldehyde, 4-hydroxybenzaldehyde, syringaldehyde, vanillin, and ferulic, p-coumaric, syringic and vanillic acid, as sole carbon sources. Second, we report that C. basilensis detoxified and metabolized ~98 % LDMICs present in dilute acid-pretreated MG hydrolysates. Last, this bioabatement resulted in significant payoffs during acetone-butanol-ethanol (ABE) fermentation by C. beijerinckii: 70, 50 and 73 % improvement in ABE concentration, yield and productivity, respectively. Together, our results show that biological detoxification of acid-pretreated MG hydrolysates prior to fermentation is feasible and beneficial. PMID:27400988

  15. Enhanced mannan-derived fermentable sugars of palm kernel cake by mannanase-catalyzed hydrolysis for production of biobutanol.

    Science.gov (United States)

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

    2016-10-01

    Catalytic depolymerization of mannan composition of palm kernel cake (PKC) by mannanase was optimized to enhance the release of mannan-derived monomeric sugars for further application in acetone-butanol-ethanol (ABE) fermentation. Efficiency of enzymatic hydrolysis of PKC was studied by evaluating effects of PKC concentration, mannanase loading, hydrolysis pH value, reaction temperature and hydrolysis time on production of fermentable sugars using one-way analysis of variance (ANOVA). The ANOVA results revealed that all factors studied had highly significant effects on total sugar liberated (P<0.01). The optimum conditions for PKC hydrolysis were 20% (w/v) PKC concentration, 5% (w/w) mannanase loading, hydrolysis pH 4.5, 45°C temperature and 72h hydrolysis time. Enzymatic experiments in optimum conditions revealed total fermentable sugars of 71.54±2.54g/L were produced including 67.47±2.51g/L mannose and 2.94±0.03g/L glucose. ABE fermentation of sugar hydrolysate by Clostridium saccharoperbutylacetonicum N1-4 resulted in 3.27±1.003g/L biobutanol.

  16. Enhanced mannan-derived fermentable sugars of palm kernel cake by mannanase-catalyzed hydrolysis for production of biobutanol.

    Science.gov (United States)

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

    2016-10-01

    Catalytic depolymerization of mannan composition of palm kernel cake (PKC) by mannanase was optimized to enhance the release of mannan-derived monomeric sugars for further application in acetone-butanol-ethanol (ABE) fermentation. Efficiency of enzymatic hydrolysis of PKC was studied by evaluating effects of PKC concentration, mannanase loading, hydrolysis pH value, reaction temperature and hydrolysis time on production of fermentable sugars using one-way analysis of variance (ANOVA). The ANOVA results revealed that all factors studied had highly significant effects on total sugar liberated (P<0.01). The optimum conditions for PKC hydrolysis were 20% (w/v) PKC concentration, 5% (w/w) mannanase loading, hydrolysis pH 4.5, 45°C temperature and 72h hydrolysis time. Enzymatic experiments in optimum conditions revealed total fermentable sugars of 71.54±2.54g/L were produced including 67.47±2.51g/L mannose and 2.94±0.03g/L glucose. ABE fermentation of sugar hydrolysate by Clostridium saccharoperbutylacetonicum N1-4 resulted in 3.27±1.003g/L biobutanol. PMID:27372004

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

    Energy Technology Data Exchange (ETDEWEB)

    Sivagnanam, Kumaran [McGill University, Montreal, Quebec; Raghavan, Vijaya G. S. [McGill University, Montreal, Quebec; Shah, Manesh B [ORNL; Hettich, Robert {Bob} L [ORNL; Verberkmoes, Nathan C [ORNL; Lefsrud, Mark G [McGill University, Montreal, Quebec

    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.

  18. Predictive modeling in Clostridium acetobutylicum fermentations employing Raman spectroscopy and multivariate data analysis for real-time culture monitoring

    Science.gov (United States)

    Zu, Theresah N. K.; Liu, Sanchao; Germane, Katherine L.; Servinsky, Matthew D.; Gerlach, Elliot S.; Mackie, David M.; Sund, Christian J.

    2016-05-01

    The coupling of optical fibers with Raman instrumentation has proven to be effective for real-time monitoring of chemical reactions and fermentations when combined with multivariate statistical data analysis. Raman spectroscopy is relatively fast, with little interference from the water peak present in fermentation media. Medical research has explored this technique for analysis of mammalian cultures for potential diagnosis of some cancers. Other organisms studied via this route include Escherichia coli, Saccharomyces cerevisiae, and some Bacillus sp., though very little work has been performed on Clostridium acetobutylicum cultures. C. acetobutylicum is a gram-positive anaerobic bacterium, which is highly sought after due to its ability to use a broad spectrum of substrates and produce useful byproducts through the well-known Acetone-Butanol-Ethanol (ABE) fermentation. In this work, real-time Raman data was acquired from C. acetobutylicum cultures grown on glucose. Samples were collected concurrently for comparative off-line product analysis. Partial-least squares (PLS) models were built both for agitated cultures and for static cultures from both datasets. Media components and metabolites monitored include glucose, butyric acid, acetic acid, and butanol. Models were cross-validated with independent datasets. Experiments with agitation were more favorable for modeling with goodness of fit (QY) values of 0.99 and goodness of prediction (Q2Y) values of 0.98. Static experiments did not model as well as agitated experiments. Raman results showed the static experiments were chaotic, especially during and shortly after manual sampling.

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

    Science.gov (United States)

    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.

  20. The production of chemicals from food processing wastes using a novel fermenter separator. Annual progress report, January 1993--March 1994

    Energy Technology Data Exchange (ETDEWEB)

    Dale, M.C.; Venkatesh, K.V.; Choi, H.; Salicetti-Piazza, L.; Borgos-Rubio, N.; Okos, M.R.; Wankat, P.C.

    1994-03-15

    The basic objective of this project is to convert waste streams from the food processing industry to usable fuels and chemicals using novel bioreactors. These bioreactors should allow economical utilization of waste (whey, waste sugars, waste starch, bottling wastes, candy wastes, molasses, and cellulosic wastes) by the production of ethanol, acetone/butanol, organic acids (acetic, lactic, and gluconic), yeast diacetyl flavor, and antifungal compounds. Continuous processes incorporating various processing improvements such as simultaneous product separation and immobilized cells are being developed to allow commercial scale utilization of waste stream. The production of ethanol by a continuous reactor-separator is the process closest to commercialization with a 7,500 liter pilot plant presently sited at an Iowa site to convert whey lactose to ethanol. Accomplishments during 1993 include installation and start-up of a 7,500 liter ICRS for ethanol production at an industry site in Iowa; Donation and installation of a 200 liter yeast pilot Plant to the project from Kenyon Enterprises; Modeling and testing of a low energy system for recovery of ethanol from vapor is using a solvent absorption/extractive distillation system; Simultaneous saccharification/fermentation of raw corn grits and starch in a stirred reactor/separator; Testing of the ability of `koji` process to ferment raw corn grits in a `no-cook` process.

  1. Draft Genome Sequence of Clostridium pasteurianum NRRL B-598, a Potential Butanol or Hydrogen Producer

    OpenAIRE

    Kolek, Jan; Sedlář, Karel; Provazník, Ivo; Patáková, Petra

    2014-01-01

    We present a draft genome sequence of Clostridium pasteurianum NRRL B-598. This strain ferments saccharides by two-stage acetone-butanol (AB) fermentation, is oxygen tolerant, and has high hydrogen yields.

  2. Draft Genome Sequence of Clostridium pasteurianum NRRL B-598, a Potential Butanol or Hydrogen Producer.

    Science.gov (United States)

    Kolek, Jan; Sedlár, Karel; Provazník, Ivo; Patáková, Petra

    2014-01-01

    We present a draft genome sequence of Clostridium pasteurianum NRRL B-598. This strain ferments saccharides by two-stage acetone-butanol (AB) fermentation, is oxygen tolerant, and has high hydrogen yields. PMID:24652980

  3. Switchgrass (Panicum virgatum fermentation by Clostridium thermocellum and Clostridium saccharoperbutylacetonicum sequential culture in a continuous flow reactor

    Directory of Open Access Journals (Sweden)

    Noelia M. Elía

    2016-01-01

    Full Text Available The study was conducted to evaluate fermentation by Clostridium thermocellum and C. saccharoperbutylacetonicum in a continuous-flow, high-solids reactor. Liquid medium was continuously flowed through switchgrass (2 mm particle size at one of three flow rates: 83.33 mL h−1 (2 L d−1, 41.66 mL h−1 (1 L d−1, and 20.833 mL h−1 (0.5 L d−1. The cellulolytic phase was initiated by culturing C. thermocellum (63 °C, 24 h. The temperature was decreased (35 and C. saccharoperbutylacetonicum was inoculated. When metabolism decreased (96 h, the temperature was increased (63 °C; 24 h to permit cellulosome production by C. thermocellum. The C. saccharoperbutylacetonicum was re-inoculated and the temperature returned to 35°C. The average gross production over 9 d was 1480 mg total acids (formic, acetic lactic butyric, 207 mg total solvents (acetone, butanol, ethanol, and average dry matter disappearance was 2.8 g from 25 g non-pretreated switchgrass. There was no effect of flow rate on the product formation. These results indicate that C. thermocellum can survive and produce cellulases with C. saccharoperbutylacetonicumin a continuous-flow, high-solids reactor temperature with temperature cycling.

  4. Économie d'un procédé d'hydrolyse enzymatique et fermentation de la paille de blé pour la production d'alcool carburant Economics of a Process for Producing Alcohol Fuels by Enzymatic Hydrolysis and Fermentation of Wheat Straw

    Directory of Open Access Journals (Sweden)

    Arlie J. P.

    2006-11-01

    Full Text Available Après définition des grandes lignes d'un procédé de base d'hydrolyse-fermentation de la paille de blé, l'analyse de sensibilité montre que le rendement de l'hydrolyse a une grande importance sur les bilans énergétique et économique. Des rendements de l'ordre de 85 % permettent d'obtenir des valeurs d'investissement par tonne de pétrole économisée tout à fait comparables à celles obtenues par d'autres techniques de valorisation de la biomasse en alcool, telle la synthèse du méthanol obtenu après gazéification du bois à l'oxygène. The basic features of a process for production from cereal straw of an acetone-butanol mixture for use as a gasoline substitute are described. They include pretreatment and enzymatic hydrolysis of the substrate followed by fermentation of the sugars produced. A cost evaluation based on the performances of a reference process is presented. Then, an analysis of the sensitivity of the cost price of the process to the variation of the important parameters such as production capacity, enzyme productivity, hydrolysis yield is carried out. The energy balance of the process is presented.

  5. 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.

    Science.gov (United States)

    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. PMID:27089425

  6. Screening of ABE producing strains and study on fermenting butanol with corn cob hydrolysate%丙酮丁醇产生菌的筛选及玉米芯水解液发酵丁醇研究

    Institute of Scientific and Technical Information of China (English)

    王杰; 唐波; 葛珍珍; 周灿灿; 余晓斌

    2012-01-01

    The study on ABE producing strains screened from nature to ferment the enzymatic hydrolysate of corn cob pretreated by levigation was carried out. 205 ABE producing strains were screened from 133 forest soil samples. Among them, G -23 strain was able to use glucose, xylose and the mixture of both to ferment ABE. The results showed that corn cobs pretreated by levigation could effectively promote the enzymatic hydrolysis while the hydrolysate could be directly used in ABE fermentation. The ABE fermentation by G - 23 strain using cellulase hydrolysate pretreated by levigation was performed and then 7. 6 g/L butanol and 12. 8 g/L ABE were obtained.%对从自然界筛选的丙酮丁醇产生菌发酵玉米芯水磨酶水解液进行了研究.结果表明:从133份森林土样中筛选到的205株丙酮丁醇产生菌中,G-23菌株能够有效地利用葡萄糖、木糖以及葡萄糖和木糖的混合糖进行丙酮丁醇(acetone-butanol-ethanol,ABE)发酵.利用水磨的方法对玉米芯进行预处理,该方法能够有效提高玉米芯的酶水解效率,得到的水解液能直接进行丙酮丁醇发酵.利用G-23菌株对水磨预处理后的酶水解液进行ABE发酵,得到了较高产量的丁醇和总溶剂,分别为7.6 g/L和12.8 g/L.

  7. Ethanol fermentation

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The inulin of chicory slices was hydrolyzed enzymically and fermented to ethanol. Maximum ethanol yield was achieved with fermentation combined with saccharification, using cellulase and inulinase for saccharification. The fermenting organism was Saccharomyces cerevisiae. Kluyveromyces fragilis, containing endogenous inulinase, was also used, but with lower yield.

  8. Anaerobic biotechnological approaches for production of liquid energy carriers from biomass

    DEFF Research Database (Denmark)

    Karakashev, Dimitar Borisov; Thomsen, Anne Belinda; Angelidaki, Irini

    2007-01-01

    In recent years, increasing attention has been paid to the use of renewable biomass for energy production. Anaerobic biotechnological approaches for production of liquid energy carriers (ethanol and a mixture of acetone, butanol and ethanol) from biomass can be employed to decrease environmental...... pollution and reduce dependency on fossil fuels. There are two major biological processes that can convert biomass to liquid energy carriers via anaerobic biological breakdown of organic matter: ethanol fermentation and mixed acetone, butanol, ethanol (ABE) fermentation. The specific product formation...

  9. Biobutanol Production from Hexose and Pentose Sugars

    NARCIS (Netherlands)

    Raganati, F.; Procentese, A.; Olivieri, G.; Salatino, P.; Marzocchella, A.

    2014-01-01

    The Acetone-Butanol-Ethanol (ABE) fermentation is receiving renewed interest as a way to upgrade renewable resources for the production of products with high added value as chemicals and fuels. Main pre-requisites of fermentation feedstocks are abundance and un-competitiveness with food sources and

  10. Agricultural residues and energy crops as potentially economical and novel substrates for microbial production of butanol (a biofuel)

    Science.gov (United States)

    This review describes production of acetone butanol ethanol (ABE) from a variety of agricultural residues and energy crops employing biochemical or fermentation processes. A number of organisms are available for this bioconversion including Clostridium beijerinckii P260, C. beijerinckii BA101, C. a...

  11. Metabolic engineering toward 1-butanol derivatives in solvent producing clostridia

    NARCIS (Netherlands)

    Siemerink, M.A.J.

    2010-01-01

    Chapter 1 of this thesis gives an overview about the history of the acetone, butanol and ethanol (ABE) fermentation. The responsible solventogenic clostridia with their central metabolism are briefly discussed. Despite the fact that scientific research on the key organisms of the ABE process has con

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

    OpenAIRE

    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 ...

  13. The Faraday effect revisited

    DEFF Research Database (Denmark)

    Cornean, Horia; Nenciu, Gheorghe

    2009-01-01

    This paper is the second in a series revisiting the (effect of) Faraday rotation. We formulate and prove the thermodynamic limit for the transverse electric conductivity of Bloch electrons, as well as for the Verdet constant. The main mathematical tool is a regularized magnetic and geometric...

  14. A Hydrostatic Paradox Revisited

    Science.gov (United States)

    Ganci, Salvatore

    2012-01-01

    This paper revisits a well-known hydrostatic paradox, observed when turning upside down a glass partially filled with water and covered with a sheet of light material. The phenomenon is studied in its most general form by including the mass of the cover. A historical survey of this experiment shows that a common misunderstanding of the phenomenon…

  15. Protein modification by fermentation

    DEFF Research Database (Denmark)

    Barkholt, Helle Vibeke; Jørgensen, P.B.; Sørensen, Anne Dorthe;

    1998-01-01

    The effect of fermentation on components of potential significance for the allergenicity of pea was analyzed. Pea flour was fermented with three lactic acid bacteria, Pediococcus pentosaceus, Lactococcus raffinolactis, and Lactobacillus plantarum, and two fungi, Rhizopus microsporus, var...

  16. Probiotic fermented dairy products

    Directory of Open Access Journals (Sweden)

    Adnan Tamime

    2003-04-01

    Full Text Available Fermented dairy products are the most popular vehicle used in theindustry for the implantation of the probiotic microflora in humans. Therefore this paper provides an overview of new knowledge on probiotic fermented dairy products. It involves historical developments, commercial probiotic microorganisms and products, and their therapeutic properties, possibilities of quality improvement of different types of newly developed fermented dairy products together with fermented goat’s milk products.

  17. Remembered Experiences and Revisit Intentions

    DEFF Research Database (Denmark)

    Barnes, Stuart; Mattsson, Jan; Sørensen, Flemming

    2016-01-01

    path modelling, we examine the impact of positive affect tourist experiences on the development of revisit intentions. We find that longer-term remembered experiences have the strongest impact on revisit intentions, more so than predicted or immediate memory after an event. We also find that remembered...

  18. Deterministic Graphical Games Revisited

    DEFF Research Database (Denmark)

    Andersson, Daniel; Hansen, Kristoffer Arnsfelt; Miltersen, Peter Bro;

    2008-01-01

    We revisit the deterministic graphical games of Washburn. A deterministic graphical game can be described as a simple stochastic game (a notion due to Anne Condon), except that we allow arbitrary real payoffs but disallow moves of chance. We study the complexity of solving deterministic graphical...... games and obtain an almost-linear time comparison-based algorithm for computing an equilibrium of such a game. The existence of a linear time comparison-based algorithm remains an open problem.......We revisit the deterministic graphical games of Washburn. A deterministic graphical game can be described as a simple stochastic game (a notion due to Anne Condon), except that we allow arbitrary real payoffs but disallow moves of chance. We study the complexity of solving deterministic graphical...

  19. Fossil turbulence revisited

    CERN Document Server

    Gibson, C H

    1999-01-01

    A theory of fossil turbulence presented in the 11th Liege Colloquium on Marine turbulence is "revisited" in the 29th Liege Colloquium "Marine Turbulence Revisited". The Gibson (1980) theory applied universal similarity theories of turbulence and turbulent mixing to the vertical evolution of an isolated patch of turbulence in a stratified fluid as it is constrained and fossilized by buoyancy forces. Towed oceanic microstructure measurements of Schedvin (1979) confirmed the predicted universal constants. Universal constants, spectra, hydrodynamic phase diagrams (HPDs) and other predictions of the theory have been reconfirmed by a wide variety of field and laboratory observations. Fossil turbulence theory has many applications; for example, in marine biology, laboratory and field measurements suggest phytoplankton species with different swimming abilities adjust their growth strategies differently by pattern recognition of several days of turbulence-fossil-turbulence dissipation and persistence times above thres...

  20. Fermented milk for hypertension

    DEFF Research Database (Denmark)

    Usinger, Lotte; Reimer, Christina; Ibsen, Hans

    2012-01-01

    Fermented milk has been suggested to have a blood pressure lowering effect through increased content of proteins and peptides produced during the bacterial fermentation. Hypertension is one of the major risk factors for cardiovascular disease world wide and new blood pressure reducing lifestyle...... interventions, such as fermented milk, would be of great importance....

  1. Reverse cholesterol transport revisited

    Institute of Scientific and Technical Information of China (English)

    Astrid; E; van; der; Velde

    2010-01-01

    Reverse cholesterol transport was originally described as the high-density lipoprotein-mediated cholesterol flux from the periphery via the hepatobiliary tract to the intestinal lumen, leading to fecal excretion. Since the introduction of reverse cholesterol transport in the 1970s, this pathway has been intensively investigated. In this topic highlight, the classical reverse cholesterol transport concepts are discussed and the subject reverse cholesterol transport is revisited.

  2. The bar instability revisited

    OpenAIRE

    Chiodi, Filippo; Andreotti, Bruno; Claudin, Philippe

    2012-01-01

    The river bar instability is revisited, using a hydrodynamical model based on Reynolds averaged Navier-Stokes equations. The results are contrasted with the standard analysis based on shallow water Saint-Venant equations. We first show that the stability of both transverse modes (ripples) and of small wavelength inclined modes (bars) predicted by the Saint-Venant approach are artefacts of this hydrodynamical approximation. When using a more reliable hydrodynamical model, the dispersion relati...

  3. Oxidative phosphorylation revisited

    DEFF Research Database (Denmark)

    Nath, Sunil; Villadsen, John

    2015-01-01

    The fundamentals of oxidative phosphorylation and photophosphorylation are revisited. New experimental data on the involvement of succinate and malate anions respectively in oxidative phosphorylation and photophosphorylation are presented. These new data offer a novel molecular mechanistic...... are proton‐dicarboxylic acid anion cotransporters and not simply electrogenic proton translocators. These results necessitate revision of previous theories of biological energy transduction, coupling, and ATP synthesis. The novel molecular mechanism is extended to cover ATP synthesis in prokaryotes...

  4. Reframing in dentistry: revisited.

    Science.gov (United States)

    Nuvvula, Sivakumar; Kamatham, Rekalakshmi; Challa, Ramasubbareddy; Asokan, Sharath

    2013-01-01

    The successful practice of dentistry involves a good combination of technical skills and soft skills. Soft skills or communication skills are not taught extensively in dental schools and it can be challenging to learn and at times in treating dental patients. Guiding the child's behavior in the dental operatory is one of the preliminary steps to be taken by the pediatric dentist and one who can successfully modify the behavior can definitely pave the way for a life time comprehensive oral care. This article is an attempt to revisit a simple behavior guidance technique, reframing and explain the possible psychological perspectives behind it for better use in the clinical practice. PMID:24021326

  5. Analogue Magnetism Revisited

    CERN Document Server

    Osano, Bob

    2016-01-01

    In this article we revisit the significance of the often debated structural similarity between the equations of electromagnetism and fluid dynamics. Although the matching of the two sets of equations has successfully been done for non-dissipative forms of the equations, little has been done for cases where the dissipative terms are non-negligible. We consider the consequence of non-negligible viscosity and diffusivity, and how the fine-tuning of these parameters could allow fluid dynamics to be used to indirectly study certain properties of magnetic fields.

  6. Экстракционное извлечение n-бутанола и сопутствующих растворителей из среды ацетонобутилового брожения

    OpenAIRE

    Григорьев, Ю. В.; Ивашкевич, О. А.; Лещев, С. М.; Григорьева, И. М.; Болотник, Е. В.

    2013-01-01

    Extraction was found to be effective method for isolation of n-butyl alcohol and other accompanying products (ethanol, acetone) from culture broth of acetone-butanol fermentation. Culture broth obtained by fermentation of rye flour by Clostridium acetobutili-cum, was used as a object of research. Chloroform, toluene, tributylphosphate, rape seed oil, n-octyl alcohol and n-decyl alcohol were tested as extractants. Among them, n-decanol having high extraction capacity, low inflammability, volatil...

  7. Asian fungal fermented food

    NARCIS (Netherlands)

    Nout, M.J.R.; Aidoo, K.E.

    2010-01-01

    In Asian countries, there is a long history of fermentation of foods and beverages. Diverse micro-organisms, including bacteria, yeasts and moulds, are used as starters, and a wide range of ingredients can be made into fermented foods. The main raw materials include cereals, leguminous seeds, vegeta

  8. Quantum duel revisited

    Science.gov (United States)

    Schmidt, Alexandre G. M.; Paiva, Milena M.

    2012-03-01

    We revisit the quantum two-person duel. In this problem, both Alice and Bob each possess a spin-1/2 particle which models dead and alive states for each player. We review the Abbott and Flitney result—now considering non-zero α1 and α2 in order to decide if it is better for Alice to shoot or not the second time—and we also consider a duel where players do not necessarily start alive. This simple assumption allows us to explore several interesting special cases, namely how a dead player can win the duel shooting just once, or how can Bob revive Alice after one shot, and the better strategy for Alice—being either alive or in a superposition of alive and dead states—fighting a dead opponent.

  9. Seven Issues Revisited

    DEFF Research Database (Denmark)

    Grønbæk, Kaj; Whitehead, Jim; De Bra, Paul;

    2002-01-01

    It has been 15 years since the original presentation by Frank Halasz at Hypertext'87 on seven issues for the next generation of hypertext systems. These issues are: Search and Query Composites Virtual Structures Computation in/over hypertext network Versioning Collaborative Work Extensibility...... and Tailorability Since that time, these issues have formed the nucleus of multiple research agendas within the Hypertext community. Befitting this direction-setting role, the issues have been revisited several times, by Halasz in his 1991 Hypertext keynote talk, and by Randy Trigg in his 1996 Hypertext keynote...... five years later. Additionally, over the intervening 15 years, many research systems have addressed the original seven issues, and new research avenues have opened up. The goal of this panel is to begin the process of developing a new set of seven issues for the next generation of hypertext system...

  10. Deterministic Graphical Games Revisited

    DEFF Research Database (Denmark)

    Andersson, Klas Olof Daniel; Hansen, Kristoffer Arnsfelt; Miltersen, Peter Bro;

    2012-01-01

    , such as retrograde analysis, have been rediscovered independently. We then revisit Washburn’s deterministic graphical games (DGGs), a natural generalization of chess-like games to arbitrary zero-sum payoffs. We study the complexity of solving DGGs and obtain an almost-linear time comparison-based algorithm...... for finding optimal strategies in such games. The existence of a linear time comparison-based algorithm remains an open problem.......Starting from Zermelo’s classical formal treatment of chess, we trace through history the analysis of two-player win/lose/draw games with perfect information and potentially infinite play. Such chess-like games have appeared in many different research communities, and methods for solving them...

  11. Reframing in dentistry: Revisited

    Directory of Open Access Journals (Sweden)

    Sivakumar Nuvvula

    2013-01-01

    Full Text Available The successful practice of dentistry involves a good combination of technical skills and soft skills. Soft skills or communication skills are not taught extensively in dental schools and it can be challenging to learn and at times in treating dental patients. Guiding the child′s behavior in the dental operatory is one of the preliminary steps to be taken by the pediatric dentist and one who can successfully modify the behavior can definitely pave the way for a life time comprehensive oral care. This article is an attempt to revisit a simple behavior guidance technique, reframing and explain the possible psychological perspectives behind it for better use in the clinical practice.

  12. Life quality index revisited

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager

    2004-01-01

    The derivation of the life quality index (LQI) is revisited for a revision. This revision takes into account the unpaid but necessary work time needed to stay alive in clean and healthy conditions to be fit for effective wealth producing work and to enjoyable free time. Dimension analysis...... at birth should not vary between countries. Finally the distributional assumptions are relaxed as compared to the assumptions made in an earlier work by the author. These assumptions concern the calculation of the life expectancy change due to the removal of an accident source. Moreover a simple public...... consistency problems with the standard power function expression of the LQI are pointed out. It is emphasized that the combination coefficient in the convex differential combination between the relative differential of the gross domestic product per capita and the relative differential of the expected life...

  13. Firewall Configuration Errors Revisited

    CERN Document Server

    Wool, Avishai

    2009-01-01

    The first quantitative evaluation of the quality of corporate firewall configurations appeared in 2004, based on Check Point FireWall-1 rule-sets. In general that survey indicated that corporate firewalls were often enforcing poorly written rule-sets, containing many mistakes. The goal of this work is to revisit the first survey. The current study is much larger. Moreover, for the first time, the study includes configurations from two major vendors. The study also introduce a novel "Firewall Complexity" (FC) measure, that applies to both types of firewalls. The findings of the current study indeed validate the 2004 study's main observations: firewalls are (still) poorly configured, and a rule-set's complexity is (still) positively correlated with the number of detected risk items. Thus we can conclude that, for well-configured firewalls, ``small is (still) beautiful''. However, unlike the 2004 study, we see no significant indication that later software versions have fewer errors (for both vendors).

  14. The bar instability revisited

    CERN Document Server

    Chiodi, Filippo; Claudin, Philippe

    2012-01-01

    The river bar instability is revisited, using a hydrodynamical model based on Reynolds averaged Navier-Stokes equations. The results are contrasted with the standard analysis based on shallow water Saint-Venant equations. We first show that the stability of both transverse modes (ripples) and of small wavelength inclined modes (bars) predicted by the Saint-Venant approach are artefacts of this hydrodynamical approximation. When using a more reliable hydrodynamical model, the dispersion relation does not present any maximum of the growth rate when the sediment transport is assumed to be locally saturated. The analysis therefore reveals the fundamental importance of the relaxation of sediment transport towards equilibrium as it it is responsible for the stabilisation of small wavelength modes. This dynamical mechanism is characterised by the saturation number, defined as the ratio of the saturation length to the water depth Lsat/H. This dimensionless number controls the transition from ripples (transverse patte...

  15. Logistics Innovation Process Revisited

    DEFF Research Database (Denmark)

    Gammelgaard, Britta; Su, Shong-Iee Ivan; Yang, Su-Lan

    2011-01-01

    that was triggered by the practical needs of new ways of handling material flows of a hospital. This approach made it possible to revisit theory on logistics innovation process. Findings – Apart from the tangible benefits reported to the case hospital, five findings can be extracted from this study: the logistics...... on internal stakeholders as on external relationships; and logistics innovation process may start out as a dialectic, conflict ridden process and end up in a well-ordered goal-oriented teleological process. Research limitations/implications – In general, the study contributes to the knowledge base...... on an existing model by methodological triangulation in order to learn more about the qualities of actual processes and their implications for theory and practice....

  16. Revisiting the Lambert's Problem

    CERN Document Server

    Izzo, Dario

    2014-01-01

    The orbital boundary value problem, also known as Lambert Problem, is revisited. Building upon Lancaster and Blanchard approach, new relations are revealed and a new variable representing all problem classes, under L-similarity, is used to express the time of flight equation. In the new variable, the time of flight curves have two oblique asymptotes and they mostly appear to be conveniently approximated by piecewise continuous lines. We use and invert such a simple approximation to provide an efficient initial guess to an Householder iterative method that is then able to converge, for the single revoltuion case, in only two iterations. The resulting algorithm is compared to Gooding's procedure revealing to be numerically as accurate, while having a smaller computational complexity.

  17. Klein's double discontinuity revisited

    DEFF Research Database (Denmark)

    Winsløw, Carl; Grønbæk, Niels

    2014-01-01

    Much effort and research has been invested into understanding and bridging the ‘gaps’ which many students experience in terms of contents and expectations as they begin university studies with a heavy component of mathematics, typically in the form of calculus courses. We have several studies...... of bridging measures, success rates and many other aspects of these “entrance transition” problems. In this paper, we consider the inverse transition, experienced by university students as they revisit core parts of high school mathematics (in particular, calculus) after completing the undergraduate...... mathematics courses which are mandatory to become a high school teacher of mathematics. To what extent does the “advanced” experience enable them to approach the high school calculus in a deeper and more autonomous way ? To what extent can “capstone” courses support such an approach ? How could it be hindered...

  18. Rumen microorganisms and fermentation

    Directory of Open Access Journals (Sweden)

    AR Castillo-González

    2014-01-01

    Full Text Available The rumen consists of a complex ecosystem where nutrients consumed by ruminants are digested by fermentation process, which is executed by diverse microorganisms such as bacteria, protozoa, and fungi. A symbiotic relationship is found among different groups of microorganisms due to the diverse nature of these microbial species and their adaptability and interactions also coexist. The ruminant provides the necessary environment for the establishment of such microorganisms, while the microorganisms obtain energy from the host animal from microbial fermentation end products. Within the ruminal ecosystem, the microorganisms coexist in a reduced environment and pH remains close to neutral. Rumen microorganisms are involved in the fermentation of substrates contained in thedietof the animals (carbohydrates, proteins and lipids. However, the fermentation process is not 100% effective because there are energy losses mainly in the form of methane gas (CH4, which is a problem for the environment since it is a greenhouse gas. In order to improve the efficiency of ruminant production systems, nutritional strategies that aim to manipulate ruminal fermentation using additives in the diet such as monensin, tallow, buffers, nitrogen compounds, probiotics, and others have been used. These additives allow changing the ruminal fermentation process in ways that produce better growth efficiency while decreasing energy loss. The purpose of this review is to contribute to a better understanding of the fermentation processes taking place in the rumen, providing information that can be applied in the development of new nutritional strategies for the improvement of the digestion process to achieve maximum production.

  19. Ethanol by continuous fermentation

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    EtOH is produced by continuous fermentation of molasses. Thus, molasses diluted to 20/sup 0/ Brix was inoculated with bakers' yeast and fermented at 32/sup 0/. When the medium reached 4% EtOH, it was circulated through a centrifuge. The concentrated yeast was recycled to the fermentor and the supernatant was sent to a still. After distillation, the still residue was returned to the fermentor. When the initial charge was entirely fermented, 13 kg molasses of 40/sup 0/ Brix was added to the fermentor per hour, and the yield of EtOH was 1.7 kg/100 L-hour.

  20. Filamentous Fungi Fermentation

    DEFF Research Database (Denmark)

    Nørregaard, Anders; Stocks, Stuart; Woodley, John;

    2014-01-01

    Filamentous fungi (including microorganisms such as Aspergillus niger and Rhizopus oryzae) represent an enormously important platform for industrial fermentation. Two particularly valuable features are the high yield coefficients and the ability to secrete products. However, the filamentous...

  1. Revisiting energy efficiency fundamentals

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Lombard, L.; Velazquez, D. [Grupo de Termotecnia, Escuela Superior de Ingenieros, Universidad de Sevilla, Camino de los Descubrimientos s/n, 41092 Seville (Spain); Ortiz, J. [Building Research Establishment (BRE), Garston, Watford, WD25 9XX (United Kingdom)

    2013-05-15

    Energy efficiency is a central target for energy policy and a keystone to mitigate climate change and to achieve a sustainable development. Although great efforts have been carried out during the last four decades to investigate the issue, focusing into measuring energy efficiency, understanding its trends and impacts on energy consumption and to design effective energy efficiency policies, many energy efficiency-related concepts, some methodological problems for the construction of energy efficiency indicators (EEI) and even some of the energy efficiency potential gains are often ignored or misunderstood, causing no little confusion and controversy not only for laymen but even for specialists. This paper aims to revisit, analyse and discuss some efficiency fundamental topics that could improve understanding and critical judgement of efficiency stakeholders and that could help in avoiding unfounded judgements and misleading statements. Firstly, we address the problem of measuring energy efficiency both in qualitative and quantitative terms. Secondly, main methodological problems standing in the way of the construction of EEI are discussed, and a sequence of actions is proposed to tackle them in an ordered fashion. Finally, two key topics are discussed in detail: the links between energy efficiency and energy savings, and the border between energy efficiency improvement and renewable sources promotion.

  2. Cats protecting birds revisited.

    Science.gov (United States)

    Fan, Meng; Kuang, Yang; Feng, Zhilan

    2005-09-01

    In this paper, we revisit the dynamical interaction among prey (bird), mesopredator (rat), and superpredator (cat) discussed in [Courchamp, F., Langlais, M., Sugihara, G., 1999. Cats protecting birds: modelling the mesopredator release effect. Journal of Animal Ecology 68, 282-292]. First, we develop a prey-mesopredator-superpredator (i.e., bird-rat-cat, briefly, BRC) model, where the predator's functional responses are derived based on the classical Holling's time budget arguments. Our BRC model overcomes several model construction problems in Courchamp et al. (1999), and admits richer, reasonable and realistic dynamics. We explore the possible control strategies to save or restore the bird by controlling or eliminating the rat or the cat when the bird is endangered. We establish the existence of two types of mesopredator release phenomena: severe mesopredator release, where once superpredators are suppressed, a burst of mesopredators follows which leads their shared prey to extinction; and mild mesopredator release, where the mesopredator release could assert more negative impact on the endemic prey but does not lead the endemic prey to extinction. A sharp sufficient criterion is established for the occurrence of severe mesopredator release. We also show that, in a prey-mesopredator-superpredator trophic food web, eradication of introduced superpredators such as feral domestic cats in the BRC model, is not always the best solution to protect endemic insular prey. The presence of a superpredator may have a beneficial effect in such systems. PMID:15998496

  3. Lorentz violation naturalness revisited

    Science.gov (United States)

    Belenchia, Alessio; Gambassi, Andrea; Liberati, Stefano

    2016-06-01

    We revisit here the naturalness problem of Lorentz invariance violations on a simple toy model of a scalar field coupled to a fermion field via a Yukawa interaction. We first review some well-known results concerning the low-energy percolation of Lorentz violation from high energies, presenting some details of the analysis not explicitly discussed in the literature and discussing some previously unnoticed subtleties. We then show how a separation between the scale of validity of the effective field theory and that one of Lorentz invariance violations can hinder this low-energy percolation. While such protection mechanism was previously considered in the literature, we provide here a simple illustration of how it works and of its general features. Finally, we consider a case in which dissipation is present, showing that the dissipative behaviour does not percolate generically to lower mass dimension operators albeit dispersion does. Moreover, we show that a scale separation can protect from unsuppressed low-energy percolation also in this case.

  4. Benjamin Franklin and Mesmerism, revisited.

    Science.gov (United States)

    McConkey, Kevin M; Perry, Campbell

    2002-10-01

    The authors revisit and update their previous historiographical note (McConkey & Perry, 1985) on Benjamin Franklin's involvement with and investigation of animal magnetism or mesmerism. They incorporate more recent literature and offer additional comment about Franklin's role in and views about mesmerism. Franklin had a higher degree of personal involvement with and a more detailed opinion of mesmerism than has been previously appreciated.

  5. The "Mushroom Cloud" Demonstration Revisited

    Science.gov (United States)

    Panzarasa, Guido; Sparnacci, Katia

    2013-01-01

    A revisitation of the classical "mushroom cloud" demonstration is described. Instead of aniline and benzoyl peroxide, the proposed reaction involves household chemicals such as alpha-pinene (turpentine oil) and trichloroisocyanuric acid ("Trichlor") giving an impressive demonstration of oxidation and combustion reactions that…

  6. Commercial Biomass Syngas Fermentation

    Directory of Open Access Journals (Sweden)

    James Daniell

    2012-12-01

    Full Text Available The use of gas fermentation for the production of low carbon biofuels such as ethanol or butanol from lignocellulosic biomass is an area currently undergoing intensive research and development, with the first commercial units expected to commence operation in the near future. In this process, biomass is first converted into carbon monoxide (CO and hydrogen (H2-rich synthesis gas (syngas via gasification, and subsequently fermented to hydrocarbons by acetogenic bacteria. Several studies have been performed over the last few years to optimise both biomass gasification and syngas fermentation with significant progress being reported in both areas. While challenges associated with the scale-up and operation of this novel process remain, this strategy offers numerous advantages compared with established fermentation and purely thermochemical approaches to biofuel production in terms of feedstock flexibility and production cost. In recent times, metabolic engineering and synthetic biology techniques have been applied to gas fermenting organisms, paving the way for gases to be used as the feedstock for the commercial production of increasingly energy dense fuels and more valuable chemicals.

  7. Xylose fermentation to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, J.D.

    1993-01-01

    The past several years have seen tremendous progress in the understanding of xylose metabolism and in the identification, characterization, and development of strains with improved xylose fermentation characteristics. A survey of the numerous microorganisms capable of directly fermenting xylose to ethanol indicates that wild-type yeast and recombinant bacteria offer the best overall performance in terms of high yield, final ethanol concentration, and volumetric productivity. The best performing bacteria, yeast, and fungi can achieve yields greater than 0.4 g/g and final ethanol concentrations approaching 5%. Productivities remain low for most yeast and particularly for fungi, but volumetric productivities exceeding 1.0 g/L-h have been reported for xylose-fermenting bacteria. In terms of wild-type microorganisms, strains of the yeast Pichia stipitis show the most promise in the short term for direct high-yield fermentation of xylose without byproduct formation. Of the recombinant xylose-fermenting microorganisms developed, recombinant E. coli ATTC 11303 (pLOI297) exhibits the most favorable performance characteristics reported to date.

  8. Fermentative biofuels production

    International Nuclear Information System (INIS)

    The limited reserves and increasing prices of fossil carbohydrates, as well as the global warming due to their utilization, impose the finding of renewable energy sources. Because of this, since decades an increasing interest in production of alcohols, which can be used as a fuel additives or fuels for direct replacement in gasoline engines, is observed. Alcohols can be obtained chemically or as products of microbial metabolism of different species in fermentation of sugars or starchy materials. In the present review are summarized different fermentative pathways for production of all alcohols, which are or could be used as biofuels. The focus of the paper is on production limitations, strains development and economical perspectives. Key words: fermentation, biofuel, alcohols

  9. 焼酎蒸留廃液処理としてのアセトン・ブタノール発酵

    OpenAIRE

    小宮山, 晶子; 小林, 元太; 園元, 謙二; 石崎, 文彬; 吉野, 貞蔵; Komiyama, Akiko; Kobayashi, Genta; Sonomoto, Kenji; Ishizaki, Ayaaki; Yoshino, Sadazo

    2001-01-01

    Shochu distillery waste contains high suspended solid (SS) material, so that high biochemical oxygen demand (BOD) concentration indicates above 40,000ppm. Shochu distillery waste is easy to be spoiled at ambient temperature within a few days. A study for the feasibility of utilizing shochu distillery waste as a substratc for acetone, butanol and ethanol fermentation by Clostridium saccharoperbutylacetonicum N1-4 (ATCC13564) was carried out. Shochu distillery waste used a s the solevants subs...

  10. Biobutanol from cheese whey

    OpenAIRE

    Becerra, Manuel; Cerdán, María Esperanza; González-Siso, María Isabel

    2015-01-01

    At present, due to environmental and economic concerns, it is urgent to evolve efficient, clean and secure systems for the production of advanced biofuels from sustainable cheap sources. Biobutanol has proved better characteristics than the more widely used bioethanol, however the main disadvantage of biobutanol is that it is produced in low yield and titer by ABE (acetone-butanol-ethanol) fermentation, this process being not competitive from the economic point of view. In this review we summ...

  11. Utilizing Municipal and Industrial Wastes for the Production of Bioproducts: from Metagenomics to Bioproducts

    OpenAIRE

    Ellis, Joshua T.

    2013-01-01

    Global energy requirements are heavily dependent on fossil fuels such as oil, coal, and natural gas. With the expectation of fossil fuels being exhausted in the future, novel strategies need to be discovered for alternative energy generation. Biofuels such as acetone, butanol, ethanol, and hydrogen gas are gaining interest as high value energy sources. These fuels can be produced by anaerobic clostridia as metabolic byproducts of fermentation. The capability to produce these biofuels has been...

  12. Atmospheric predictability revisited

    Directory of Open Access Journals (Sweden)

    Lizzie S. R. Froude

    2013-06-01

    Full Text Available This article examines the potential to improve numerical weather prediction (NWP by estimating upper and lower bounds on predictability by re-visiting the original study of Lorenz (1982 but applied to the most recent version of the European Centre for Medium Range Weather Forecasts (ECMWF forecast system, for both the deterministic and ensemble prediction systems (EPS. These bounds are contrasted with an older version of the same NWP system to see how they have changed with improvements to the NWP system. The computations were performed for the earlier seasons of DJF 1985/1986 and JJA 1986 and the later seasons of DJF 2010/2011 and JJA 2011 using the 500-hPa geopotential height field. Results indicate that for this field, we may be approaching the limit of deterministic forecasting so that further improvements might only be obtained by improving the initial state. The results also show that predictability calculations with earlier versions of the model may overestimate potential forecast skill, which may be due to insufficient internal variability in the model and because recent versions of the model are more realistic in representing the true atmospheric evolution. The same methodology is applied to the EPS to calculate upper and lower bounds of predictability of the ensemble mean forecast in order to explore how ensemble forecasting could extend the limits of the deterministic forecast. The results show that there is a large potential to improve the ensemble predictions, but for the increased predictability of the ensemble mean, there will be a trade-off in information as the forecasts will become increasingly smoothed with time. From around the 10-d forecast time, the ensemble mean begins to converge towards climatology. Until this point, the ensemble mean is able to predict the main features of the large-scale flow accurately and with high consistency from one forecast cycle to the next. By the 15-d forecast time, the ensemble mean has lost

  13. Enceladus' tidal dissipation revisited

    Science.gov (United States)

    Tobie, Gabriel; Behounkova, Marie; Choblet, Gael; Cadek, Ondrej; Soucek, Ondrej

    2016-10-01

    A series of chemical and physical evidence indicates that the intense activity at Enceladus' South Pole is related to a subsurface salty water reservoir underneath the tectonically active ice shell. The detection of a significant libration implies that this water reservoir is global and that the average ice shell thickness is about 20-25km (Thomas et al. 2016). The interpretation of gravity and topography data further predicts large variations in ice shell thickness, resulting in a shell potentially thinner than 5 km in the South Polar Terrain (SPT) (Cadek et al. 2016). Such an ice shell structure requires a very strong heat source in the interior, with a focusing mechanism at the SPT. Thermal diffusion through the ice shell implies that at least 25-30 GW is lost into space by passive diffusion, implying a very efficient dissipation mechanism in Enceladus' interior to maintain such an ocean/ice configuration thermally stable.In order to determine in which conditions such a large dissipation power may be generated, we model the tidal response of Enceladus including variable ice shell thickness. For the rock core, we consider a wide range of rheological parameters representative of water-saturated porous rock materials. We demonstrate that the thinning toward the South Pole leads to a strong increase in heat production in the ice shell, with a optimal thickness obtained between 1.5 and 3 km, depending on the assumed ice viscosity. Our results imply that the heat production in the ice shell within the SPT may be sufficient to counterbalance the heat loss by diffusion and to power eruption activity. However, outside the SPT, a strong dissipation in the porous core is required to counterbalance the diffusive heat loss. We show that about 20 GW can be generated in the core, for an effective viscosity of 1012 Pa.s, which is comparable to the effective viscosity estimated in water-saturated glacial tills on Earth. We will discuss the implications of this revisited tidal

  14. Revisiting SU(N) integrals

    CERN Document Server

    Zuber, Jean-Bernard

    2016-01-01

    In this note, I revisit integrals over $\\SU(N)$ of the form $ \\int DU\\, U_{i_1j_1}\\cdots U_{i_pj_p}\\Ud_{k_1l_1}\\cdots \\Ud_{k_nl_n}$. While the case $p=n$ is well known, it seems that explicit expressions for $p=n+N$ had not appeared in the literature. Similarities and differences, in particular in the large $N$ limit, between the two cases are discussed

  15. The Damped String Problem Revisited

    CERN Document Server

    Gesztesy, Fritz

    2010-01-01

    We revisit the damped string equation on a compact interval with a variety of boundary conditions and derive an infinite sequence of trace formulas associated with it, employing methods familiar from supersymmetric quantum mechanics. We also derive completeness and Riesz basis results (with parentheses) for the associated root functions under less smoothness assumptions on the coefficients than usual, using operator theoretic methods (rather than detailed eigenvalue and root function asymptotics) only.

  16. Markowitz Revisited: Social Portfolio Engineering

    OpenAIRE

    Gasser, Stephan; Kremser, Thomas; Rammerstorfer, Margarethe; Weinmayer, Karl

    2014-01-01

    In recent years socially responsible investing has become an increasingly more popular subject with both private and institutional investors. At the same time, a number of scientific papers have been published on socially responsible investments (SRIs), covering a broad range of topics, from what actually defines SRIs to the financial performance of SRI funds in contrast to non-SRI funds. In this paper, we revisit Markowitz' Portfolio Selection Theory and propose a modification...

  17. Leadership and Management Theories Revisited

    OpenAIRE

    Madsen, Mona Toft

    2001-01-01

    The goal of the paper is to revisit and analyze key contributions to the understanding of leadership and management. As a part of the discussion a role perspective that allows for additional and/or integrated leader dimensions, including a change-centered, will be outlined. Seemingly, a major challenge on the substantive level is the integration of soft and hard managerial functions, while the concepts used in presenting these should at least in transition be able to contain a distinction bet...

  18. The power reinforcement framework revisited

    DEFF Research Database (Denmark)

    Nielsen, Jeppe; Andersen, Kim Normann; Danziger, James N.

    2016-01-01

    public organizations. This article revisits the 30-yearold power reinforcement framework by means of an empirical analysis on the use of mobile technology in a large-scale programme in Danish public sector home care. It explores whether and to what extent administrative management has controlled decision......-dominated and centrally controlled technologies that were the main focus of the 1970s and 1980s studies. Yet this study concludes that there is general support for the reinforcement framework in the contemporary application of mobile technology in public sector home care....

  19. Leadership and Management Theories Revisited

    DEFF Research Database (Denmark)

    Madsen, Mona Toft

    2001-01-01

    The goal of the paper is to revisit and analyze key contributions to the understanding of leadership and management. As a part of the discussion a role perspective that allows for additional and/or integrated leader dimensions, including a change-centered, will be outlined. Seemingly, a major...... challenge on the substantive level is the integration of soft and hard managerial functions, while the concepts used in presenting these should at least in transition be able to contain a distinction between hard, soft, and general practices....

  20. Jesus and the law revisited

    Directory of Open Access Journals (Sweden)

    William R.G. Loader

    2011-06-01

    Full Text Available This article revisited the issue of Jesus’ attitude towards the Torah on the basis of a critical discussion of the most recent extensive treatment of the theme by Meier in his A marginal Jew: Rethinking the historical Jesus: Volume four: Law and love (2009. It engaged Meier’s contribution in the light of contemporary research, concluding that, whilst Meier provided an erudite analysis, his thesis that Jesus’ teaching on divorce and oaths revoked Mosaic law did not convince, for it did not adequately consider the extent to which the contemporary interpretation of the Torah could encompass such radicalisation.

  1. Des aliments tu feras medecine: Hippocrate revisite

    OpenAIRE

    Lahlou, Saadi

    1999-01-01

    "Let foods be your medicine Hippocrates revisited". In this article the author discusses the behaviour of consumers, concepts of 'health foods' and helth eating towards food and the rise of businesses built around the health food industry.

  2. TRADITIONAL FERMENTED FOODS OF LESOTHO

    Directory of Open Access Journals (Sweden)

    Tendekayi H. Gadaga

    2013-06-01

    Full Text Available This paper describes the traditional methods of preparing fermented foods and beverages of Lesotho. Information on the preparation methods was obtained through a combination of literature review and face to face interviews with respondents from Roma in Lesotho. An unstructured questionnaire was used to capture information on the processes, raw materials and utensils used. Four products; motoho (a fermented porridge, Sesotho (a sorghum based alcoholic beverage, hopose (sorghum fermented beer with added hops and mafi (spontaneously fermented milk, were found to be the main fermented foods prepared and consumed at household level in Lesotho. Motoho is a thin gruel, popular as refreshing beverage as well as a weaning food. Sesotho is sorghum based alcoholic beverage prepared for household consumption as well as for sale. It is consumed in the actively fermenting state. Mafi is the name given to spontaneously fermented milk with a thick consistency. Little research has been done on the technological aspects, including the microbiological and biochemical characteristics of fermented foods in Lesotho. Some of the traditional aspects of the preparation methods, such as use of earthenware pots, are being replaced, and modern equipment including plastic utensils are being used. There is need for further systematic studies on the microbiological and biochemical characteristics of these these products.

  3. Hydrogen Production by Thermophilic Fermentation

    NARCIS (Netherlands)

    Niel, van E.W.J.; Willquist, K.; Zeidan, A.A.; Vrije, de T.; Mars, A.E.; Claassen, P.A.M.

    2012-01-01

    Of the many ways hydrogen can be produced, this chapter focuses on biological hydrogen production by thermophilic bacteria and archaea in dark fermentations. The thermophiles are held as promising candidates for a cost-effective fermentation process, because of their relatively high yields and broad

  4. China's Fermentation Industry Develops Rapidly

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 1 Output increases steadily The main products of China's fermen-tation industry include amino acid,organic acid, enzyme preparation,yeast, starch and starch sugar, spe-cial functional fermented products,etc. Monosodium glutamate is themain product of amino acid, and cit-ric acid is the main product of or-ganic acid.

  5. Lactose fermentation by engineered Saccharomyces cerevisiae capable of fermenting cellobiose.

    Science.gov (United States)

    Liu, Jing-Jing; Zhang, Guo-Chang; Oh, Eun Joong; Pathanibul, Panchalee; Turner, Timothy L; Jin, Yong-Su

    2016-09-20

    Lactose is an inevitable byproduct of the dairy industry. In addition to cheese manufacturing, the growing Greek yogurt industry generates excess acid whey, which contains lactose. Therefore, rapid and efficient conversion of lactose to fuels and chemicals would be useful for recycling the otherwise harmful acid whey. Saccharomyces cerevisiae, a popular metabolic engineering host, cannot natively utilize lactose. However, we discovered that an engineered S. cerevisiae strain (EJ2) capable of fermenting cellobiose can also ferment lactose. This finding suggests that a cellobiose transporter (CDT-1) can transport lactose and a β-glucosidase (GH1-1) can hydrolyze lactose by acting as a β-galactosidase. While the lactose fermentation by the EJ2 strain was much slower than the cellobiose fermentation, a faster lactose-fermenting strain (EJ2e8) was obtained through serial subcultures on lactose. The EJ2e8 strain fermented lactose with a consumption rate of 2.16g/Lh. The improved lactose fermentation by the EJ2e8 strain was due to the increased copy number of cdt-1 and gh1-1 genes. Looking ahead, the EJ2e8 strain could be exploited for the production of other non-ethanol fuels and chemicals from lactose through further metabolic engineering. PMID:27457698

  6. Fermented Broth in Tyrosinase- and Melanogenesis Inhibition

    Directory of Open Access Journals (Sweden)

    Chin-Feng Chan

    2014-08-01

    Full Text Available Fermented broth has a long history of applications in the food, pharmaceutical and cosmetic industries. Recently, the use of fermented broth in skin care products is in ascendance. This review investigates the efficacy of fermented broth in inhibiting tyrosinase and melanogenesis. Possible active ingredients and hypopigmentation mechanisms of fermented broth are discussed, and potential applications of fermented broth in the cosmetic industry are also addressed.

  7. Investigation and control of fermentation processes using fermenter calorimetry

    OpenAIRE

    Meier-Schneiders, Martin; Grosshans, Ulrich; Busch, Claudia; Eigenberger, Gerhart

    1992-01-01

    It is well known, that heat generation and total metabolic activity in biological systems are strongly correlated. Thus the heat production can provide important information for the study, supervision and control of biological fermentations. Microcalorimeters are widely used for studies concerning physiology, ecology, and pharmacology. They are very sensitive, but the measuring principle exhibits methodical disadvantages for its application in biotechnology (direct control of the fermentation...

  8. Modelling ethanol production from cellulose: separate hydrolysis and fermentation versus simultaneous saccharification and fermentation

    NARCIS (Netherlands)

    Drissen, R.E.T.; Maas, R.H.W.; Tramper, J.; Beeftink, H.H.

    2009-01-01

    In ethanol production from cellulose, enzymatic hydrolysis, and fermentative conversion may be performed sequentially (separate hydrolysis and fermentation, SHF) or in a single reaction vessel (simultaneous saccharification and fermentation, SSF). Opting for either is essentially a trade-off between

  9. KANJI: AN AYURVEDIC FERMENTATIVE PREPARATION

    OpenAIRE

    Santhosh B; Jadar P. G.; Nageswara Rao

    2012-01-01

    Kanji – A unique Ayurvedic fermentative preparation was prepared as per the textual reference Rasayanasara which is mainly indicated for the Shodhana (purification) of Metals and also for various mercurial processing. But Kanji by this reference is rarely prepared and used. Hence, the pharmaceutical and preliminary physico-chemical findings of this Kanji are reported in this paper. The fermentation process started on 7th day and completed on 31st day. The prepared Kanji was golden brown color...

  10. Revisiting tourist behavior via destination brand worldness

    Directory of Open Access Journals (Sweden)

    Murat Kayak

    2016-11-01

    Full Text Available Taking tourists’ perspective rather than destination offerings as its core concept, this study introduces “perceived destination brand worldness” as a variable. Perceived destination brand worldness is defined as the positive perception that a tourist has of a country that is visited by tourists from all over the world. Then, the relationship between perceived destination brand worldness and intention to revisit is analyzed using partial least squares regression. This empirical study selects Taiwanese tourists as its sample, and the results show that perceived destination brand worldness is a direct predictor of intention to revisit. In light of these empirical findings and observations, practical and theoretical implications are discussed.

  11. n-Butanol derived from biochemical and chemical routes: A review

    Directory of Open Access Journals (Sweden)

    B. Ndaba

    2015-12-01

    Full Text Available Traditionally, bio-butanol is produced with the ABE (Acetone Butanol Ethanol process using Clostridium species to ferment sugars from biomass. However, the route is associated with some disadvantages such as low butanol yield and by-product formation (acetone and ethanol. On the other hand, butanol can be directly produced from ethanol through aldol condensation over metal oxides/ hydroxyapatite catalysts. This paper suggests that the chemical conversion route is more preferable than the ABE process, because the reaction proceeds more quickly compared to the fermentation route and fewer steps are required to get to the product.

  12. Immobilized cells in meat fermentation.

    Science.gov (United States)

    McLoughlin, A J; Champagne, C P

    1994-01-01

    The immobilization of microbial cells can contribute to fermented meat technology at two basic levels. First, the solid/semisolid nature (low available water) of the substrate restricts the mobility of cells and results in spatial organizations based on "natural immobilization" within the fermentation matrix. The microniches formed influence the fermentation biochemistry through mass transfer limitations and the subsequent development and activity of the microflora. This form of immobilization controls the nature of competition between subpopulations within the microflora and ultimately exerts an effect on the ecological competence (ability to survive and compete) of the various cultures present. Second, immobilized cell technology (ICT) can be used to enhance the ecological competence of starter cultures added to initiate the fermentation. Immobilization matrices such as alginate can provide microniches or microenvironments that protect the culture during freezing or lyophilization, during subsequent rehydration, and when in competition with indigenous microflora. The regulated release of cells from the microenvironments can also contribute to competitive ability. The regulation of both immobilization processes can result in enhanced fermentation activity. PMID:8069934

  13. Fermentation of irradiated sugarcane must

    Energy Technology Data Exchange (ETDEWEB)

    Alcarde, Andre Ricardo; Horii, Jorge [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz. Dept. de Agroindustria, Alimentos e Nutricao]. E-mail: aralcard@esalq.usp.br; Walder, Julio Marcos Melges [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia

    2003-12-01

    Bacillus and Lactobacillus are bacteria that usually contaminate the ethanolic fermentation by yeasts and my influence yeast viability. As microorganisms can be killed by ionizing radiation, the efficacy of gamma radiation in reducing the population of certain contaminating bacteria from sugarcane must was examined and, as a consequence, the beneficial effect of lethal doses of radiation on some parameters of yeast-based ethanolic fermentation was verified. Must from sugarcane juice was inoculated with bacteria of the general Bacillus and Lactobacillus. The contaminated must was irradiated with 2.0, 4.0, 6.0, 8.0 and 10.0 kGy of gamma radiation. After ethanolic fermentation by the yeast (Saccharomyces cerevisiae) the total and volatile acidity produced during the process were evaluated: yeast viability and ethanol yield were also recorded. Treatments of gamma radiation reduced the population of the contaminating bacteria in the sugarcane must. The acidity produced during the fermentation decreased as the dose rate of radiation increased. Conversely, the yeast viability increased as the dose rate of radiation increased. Gamma irradiation was an efficient treatment to decontaminate the must and improved its parameters related to ethanolic fermentation, including ethanol yield, which increased 1.9%. (author)

  14. Revisiting the Regenerative Possibilities of Ortiz

    Science.gov (United States)

    Duques, Matthew

    2004-01-01

    The author of this article revisits Simon Ortiz's poem, "From Sand Creek," in which the latter can in so few words convey both the horrific tragedy of conquest and colonization, while at the same time find a space for possibility, a means for recovery that is never about forgetting but always occurs as a kind of recuperative remembering. Ortiz…

  15. Topological string theory revisited I: The stage

    Science.gov (United States)

    Jia, Bei

    2016-08-01

    In this paper, we reformulate topological string theory using supermanifolds and supermoduli spaces, following the approach worked out by Witten (Superstring perturbation theory revisited, arXiv:1209.5461). We intend to make the construction geometrical in nature, by using supergeometry techniques extensively. The goal is to establish the foundation of studying topological string amplitudes in terms of integration over appropriate supermoduli spaces.

  16. Coccolithophorids in polar waters: Calciarcus spp. revisited

    DEFF Research Database (Denmark)

    Thomsen, Helge Abildhauge; Østergaard, Jette B.

    2014-01-01

    The genus Calciarcus is revisited here with the purpose of providing, based on additional sampling from both polar regions, an update on species diversity and morphology that can serve as a reference for future work. The geographic realm of the genus is significantly widened and a case is built...

  17. Fine structure of the butterfly diagram revisited

    Science.gov (United States)

    Major, Balázs

    The latitudinal time distribution of sunspots (butterfly diagram) was studied by Becker (1959) and Antalová & Gnevyshev (1985). Our goal is to revisit these studies. In the first case we check whether there is a poleward migration in sunspot activity. In the second case we confirm the results, and make more quantitative statements concerning their significance and the position of the activity peaks.

  18. The Rotating Morse-Pekeris Oscillator Revisited

    Science.gov (United States)

    Zuniga, Jose; Bastida, Adolfo; Requena, Alberto

    2008-01-01

    The Morse-Pekeris oscillator model for the calculation of the vibration-rotation energy levels of diatomic molecules is revisited. This model is based on the realization of a second-order exponential expansion of the centrifugal term about the minimum of the vibrational Morse oscillator and the subsequent analytical resolution of the resulting…

  19. Revisiting Basic Counseling Skills with Children

    Science.gov (United States)

    Van Velsor, Patricia

    2004-01-01

    Counseling with children can be challenging for counselors whose training focused on adult clients. The purpose of this article is to offer information to counselors seeking to improve their skills with children, revisiting a topic discussed in an earlier Journal of Counseling & Development article by P. Erdman and R. Lampe (1996). Examples of…

  20. Ethanolic fermentation of pentoses in lignocellulose hydrolysates

    Energy Technology Data Exchange (ETDEWEB)

    Hahn-Haegerdal, B.; Linden, T.; Senac, T.; Skoog, K. [Lund Univ. Chemical Center (Sweden)

    1991-12-31

    In the fermentation of lignocellulose hydrolysates to ethanol, two major problems are encountered: the fermentation of the pentose sugar xylose, and the presence of microbial inhibitors. Xylose can be directly fermented with yeasts; such as Pachysolen tannophilus, Candida shehatae, and Pichia stipis, or by isomerization of xylose to xylulose with the enzyme glucose (xylose) isomerase, and subsequent fermentation with bakers yeast, Saccharomyces cerevisiae. The direct fermentation requires low, carefully controlled oxygenation, as well as the removal of inhibitors. Also, the xylose-fermenting yeasts have a limited ethanol tolerance. The combined isomerization and fermentation with XI and S. cerevisiae gives yields and productivities comparable to those obtained in hexose fermentations without oxygenation and removal of inhibitors. However, the enzyme is not very stable in a lignocellulose hydrolysate, and S. cerevisiae has a poorly developed pentose phosphate shunt. Different strategies involving strain adaptation, and protein and genetic engineering adopted to overcome these different obstacles, are discussed.

  1. Treatment of biomass to obtain fermentable sugars

    Science.gov (United States)

    Dunson, Jr., James B.; Tucker, Melvin; Elander, Richard; Hennessey, Susan M.

    2011-04-26

    Biomass is pretreated using a low concentration of aqueous ammonia at high biomass concentration. Pretreated biomass is further hydrolyzed with a saccharification enzyme consortium. Fermentable sugars released by saccharification may be utilized for the production of target chemicals by fermentation.

  2. Yeasts Diversity in Fermented Foods and Beverages

    Science.gov (United States)

    Tamang, Jyoti Prakash; Fleet, Graham H.

    People across the world have learnt to culture and use the essential microorganisms for production of fermented foods and alcoholic beverages. A fermented food is produced either spontaneously or by adding mixed/pure starter culture(s). Yeasts are among the essential functional microorganisms encountered in many fermented foods, and are commercially used in production of baker's yeast, breads, wine, beer, cheese, etc. In Asia, moulds are predominant followed by amylolytic and alcohol-producing yeasts in the fermentation processes, whereas in Africa, Europe, Australia and America, fermented products are prepared exclusively using bacteria or bacteria-yeasts mixed cultures. This chapter would focus on the varieties of fermented foods and alcoholic beverages produced by yeasts, their microbiology and role in food fermentation, widely used commercial starters (pilot production, molecular aspects), production technology of some common commercial fermented foods and alcoholic beverages, toxicity and food safety using yeasts cultures and socio-economy

  3. Fluidized Bed Reactor as Solid State Fermenter

    OpenAIRE

    Krishnaiah, K.; Janaun, J.; Prabhakar, A.

    2005-01-01

    Various reactors such as tray, packed bed, rotating drum can be used for solid-state fermentation. In this paper the possibility of fluidized bed reactor as solid-state fermenter is considered. The design parameters, which affect the performances are identified and discussed. This information, in general can be used in the design and the development of an efficient fluidized bed solid-state fermenter. However, the objective here is to develop fluidized bed solid-state fermenter for palm kerne...

  4. Antioxidant properties of fermented mango leaf extracts.

    Science.gov (United States)

    Park, Anna; Ku, Taekyu; Yoo, Ilsou

    2015-01-01

    Antioxidant properties of mango (Mangifera indica) leaves were evaluated. Hydroalcoholic leaf extracts that were lyophilized were subsequently fermented with either Lactobacillus casei or effective microorganisms (EM) such as probiotic bacteria and/or other anaerobic organisms. Antioxidant properties were measured as a function of the mango leaf extract concentration in the fermentation broth. Tests for radical scavenging using the 1,1-diphenyl-2-picrylhydrazyl radical showed higher antioxidant activity for Lactobacillus- and EM-fermented mango leaf extracts than for the synthetic antioxidant butylated hydroxytoluene. Antioxidant activity generally increased with increasing fermented extract concentration as did the fermented extracts' polyphenol and flavonoid contents. Fermented extracts reduced reactive oxygen species generation by lipopolysaccharide in RAW 264.7 cells when measured via fluorescence of dichlorodihydrofluorescein acetate treated cells using flow cytometry. RAW 264.7 cells also showed a concentration-dependent cytotoxic effect of the fermented extracts using the 3-(4,5-dimethylthialol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Inhibition of mushroom tyrosinase activity as well as nitrite scavenging by the fermented extracts increased as fermented extract concentrations increased. Tyrosinase activity was assayed with 3,4-dihydroxyphenylalanine as substrate. Nitrite scavenging was assessed via measurement of inhibition of chromophore production from nitrite-naphthylamine-sulfanilic acid mixtures. The antioxidant properties of fermented mango leaf extracts suggest the fermented extracts may be useful in developing health food and fermentation-based beauty products.

  5. Macroscopic modelling of solid-state fermentation

    NARCIS (Netherlands)

    Hoogschagen, M.J.

    2007-01-01

    Solid-state fermentation is different from the more well known process of liquid fermentation because no free flowing water is present. The technique is primarily used in Asia. Well-known products are the foods tempe, soy sauce and saké. In industrial solid-state fermentation, the substrate usually

  6. PAT tools for fermentation processes

    DEFF Research Database (Denmark)

    Gernaey, Krist; Bolic, Andrijana; Svanholm, Bent

    2012-01-01

    knowledge is central in PAT projects. This manuscript therefore gives a brief overview of a number of PAT tools for collecting process knowledge on fermentation processes: on-line sensors, mechanistic models and small-scale equipment for high-throughput experimentation. The manuscript ends with a short......The publication of the Process Analytical Technology (PAT) guidance has been one of the most important milestones for pharmaceutical production during the past ten years. The ideas outlined in the PAT guidance are also applied in other industries, for example the fermentation industry. Process...

  7. Revisiting the 1761 Transatlantic Tsunami

    Science.gov (United States)

    Baptista, Maria Ana; Wronna, Martin; Miranda, Jorge Miguel

    2016-04-01

    The tsunami catalogs of the Atlantic include two transatlantic tsunamis in the 18th century the well known 1st November 1755 and the 31st March 1761. The 31st March 1761 earthquake struck Portugal, Spain, and Morocco. The earthquake occurred around noontime in Lisbon alarming the inhabitants and throwing down ruins of the past 1st November 1755 earthquake. According to several sources, the earthquake was followed by a tsunami observed as far as Cornwall (United Kingdom), Cork (Ireland) and Barbados (Caribbean). The analysis of macroseismic information and its compatibility with tsunami travel time information led to a source area close to the Ampere Seamount with an estimated epicenter circa 34.5°N 13°W. The estimated magnitude of the earthquake was 8.5. In this study, we revisit the tsunami observations, and we include a report from Cadiz not used before. We use the results of the compilation of the multi-beam bathymetric data, that covers the area between 34°N - 38°N and 12.5°W - 5.5°W and use the recent tectonic map published for the Southwest Iberian Margin to select among possible source scenarios. Finally, we use a non-linear shallow water model that includes the discretization and explicit leap-frog finite difference scheme to solve the shallow water equations in the spherical or Cartesian coordinate to compute tsunami waveforms and tsunami inundation and check the results against the historical descriptions to infer the source of the event. This study received funding from project ASTARTE- Assessment Strategy and Risk Reduction for Tsunamis in Europe a collaborative project Grant 603839, FP7-ENV2013 6.4-3

  8. Anaerobic xylose fermentation by Spathaspora passalidarum

    DEFF Research Database (Denmark)

    Hou, Xiaoru

    2012-01-01

    A cost-effective conversion of lignocellulosic biomass into bioethanol requires that the xylose released from the hemicellulose fraction (20–40% of biomass) can be fermented. Baker’s yeast, Saccharomyces cerevisiae, efficiently ferments glucose but it lacks the ability to ferment xylose. Xylose......-fermenting yeast such as Pichia stipitis requires accurately controlled microaerophilic conditions during the xylose fermentation, rendering the process technically difficult and expensive. In this study, it is demonstrated that under anaerobic conditions Spathaspora passalidarum showed high ethanol production...

  9. Fermentative processes for environmental remediation

    OpenAIRE

    Grilli, Selene

    2013-01-01

    The growing interest in environmental protection has led to the development of emerging biotechnologies for environmental remediation also introducing the biorefinery concept. This work mainly aimed to evaluate the applicability of innovative biotechnologies for environmental remediation and bioenergy production, throught fermentative processes. The investigated biotechnologies for waste and wastewater treatment and for the valorisation of specific feedstocks and energy recovery, were m...

  10. Cleaning Validation of Fermentation Tanks

    DEFF Research Database (Denmark)

    Salo, Satu; Friis, Alan; Wirtanen, Gun

    2008-01-01

    Reliable test methods for checking cleanliness are needed to evaluate and validate the cleaning process of fermentation tanks. Pilot scale tanks were used to test the applicability of various methods for this purpose. The methods found to be suitable for validation of the clenlinees were visula...

  11. Yeasts are essential for cocoa bean fermentation.

    Science.gov (United States)

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2014-03-17

    Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality. Cocoa bean fermentations were conducted with the addition of 200ppm Natamycin to inhibit the growth of yeasts, and the resultant microbial ecology and metabolism, bean chemistry and chocolate quality were compared with those of normal (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii and Kluyveromyces marxianus, the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in the control fermentation. In fermentations with the presence of Natamycin, the same bacterial species grew but yeast growth was inhibited. Physical and chemical analyses showed that beans fermented without yeasts had increased shell content, lower production of ethanol, higher alcohols and esters throughout fermentation and lesser presence of pyrazines in the roasted product. Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics.

  12. Anaerobic fermentation of beef cattle manure

    Science.gov (United States)

    Hashimoto, A. G.; Chen, Y. R.; Varel, V. H.

    1981-01-01

    The conversion of livestock manure and crop residues into methane and a high protein feed ingredient by thermophilic anaerobic fermentation is summarized. The major biological and operational factors involved in methanogenesis are discussed, and a kinetic model that describes the fermentation process is presented. Substrate biodegradability, fermentation temperature, and influent substrate concentration to have significant effects on CH4 production rate. Assessment of the energy requirements for anaerobic fermentation systems showed that the major energy requirement for a thermophilic system was for maintaining the fermenter temperature. The next major energy consumption was due to the mixing of the influent slurry and fermenter liquor. An approach to optimizing anaerobic fermenter s by selecting design criteria that maximize the net energy production per unit cost is presented.

  13. The Brewing Process: Optimizing the Fermentation

    Directory of Open Access Journals (Sweden)

    Teodora Coldea

    2014-11-01

    Full Text Available Beer is a carbonated alcoholic beverage obtained by alcoholic fermentation of malt wort boiled with hops. Brown beer obtained at Beer Pilot Station of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca was the result of a recipe based on blond, caramel and black malt in different proportions, water, hops and yeast. This study aimed to monitorize the evolution of wort in primary and secondary alcoholic fermentation in order to optimize the process. Two wort batches were assambled in order to increase the brewing yeast fermentation performance. The primary fermentation was 14 days, followed by another 14 days of secondary fermentation (maturation. The must fermentation monitoring was done by the automatic FermentoStar analyzer. The whole fermentation process was monitorized (temperature, pH, alcohol concentration, apparent and total wort extract.

  14. Fermentation of hexoses to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Lena [Goeteborg Univ. (Sweden). Dept. of General and Marine Microbiology]|[Chalmers Univ. of Technology, Goeteborg (Sweden). Dept of Chemical Reaction Engineering

    2000-06-01

    The Goals of the project has been: to increase the ethanol yield by reducing the by-product formation, primarily biomass and glycerol, and to prevent stuck fermentations, i.e. to maintain a high ethanol production rate simultaneously with a high ethanol yield. The studies have been performed both in defined laboratory media and in a mixture of wood- and wheat hydrolysates. The yeast strains used have been both industrial strains of bakers yeast, Saccharomyces cerevisiae, and haploid laboratory strains. The Relevance of these studies with respect to production of ethanol to be used as fuel is explained by: With the traditional process design used today, it is very difficult to reach a yield of more than 90 % of the theoretical maximal value of ethanol based on fermented hexose. During 'normal' growth and fermentation conditions in either anaerobic batch or chemostat cultures, substrate is lost as biomass and glycerol in the range of 8 to 11 % and 6 to 11 % of the substrate consumed (kg/kg). It is essential to reduce these by-products. Traditional processes are mostly batch processes, in which there is a risk that the biocatalyst, i.e. the yeast, may become inactivated. If for example yeast biomass production is avoided by use of non-growing systems, the ethanol production rate is instantaneously reduced by at least 50%. Unfortunately, even if yeast biomass production is not avoided on purpose, it is well known that stuck fermentations caused by cell death is a problem in large scale yeast processes. The main reason for stuck fermentations is nutrient imbalances. For a good process economy, it is necessary to ensure process accessibility, i.e. to maintain a high and reproducible production rate. This will both considerably reduce the necessary total volume of the fermentors (and thereby the investment costs), and moreover minimize undesirable product fall-out.

  15. Revisiting the Diffusion Problem in a Capillary Tube Geometry

    CERN Document Server

    Sullivan, Eric

    2012-01-01

    The present work revisits the problem of modeling diffusion above a stagnant liquid interface in a capillary tube geometry. In this revisitation we elucidate a misconception found in the classical model proposed by Bird et. al. Furthermore, we propose alternative explanations for thermally forced diffusion and provide a description of natural convection in the absence of forcing terms.

  16. Coccolithophorids in polar waters: Wigwamma spp. revisited

    DEFF Research Database (Denmark)

    Thomsen, Helge Abildhauge; Østergaard, Jette B.; Heldal, Mikal

    2013-01-01

    A contingent of weakly calcified coccolithophorid genera and species were described from polar regions almost 40 years ago. In the interim period a few additional findings have been reported enlarging the realm of some of the species. The genus Wigwamma is revisited here with the purpose of provi......A contingent of weakly calcified coccolithophorid genera and species were described from polar regions almost 40 years ago. In the interim period a few additional findings have been reported enlarging the realm of some of the species. The genus Wigwamma is revisited here with the purpose...... of providing, based on additional sampling from both polar regions, an update on species morphology, life history events and biogeography that can serve as a reference for the future. A new genus, Pseudowigwamma gen. nov. is described to accommodate Wigwamma scenozonion, a species which critically deviates...

  17. ConocoPhillips’ share price model revisited

    OpenAIRE

    Kitov, Ivan

    2012-01-01

    Three years ago we found a statistically reliable link between ConocoPhillips’ (NYSE: COP) stock price and the difference between the core and headline CPI in the United States. In this article, the original relationship is revisited with new data available since 2009. The agreement between the observed monthly closing price (adjusted for dividends and splits) and that predicted from the CPI difference is confirmed. The original quantitative link is validated. In order to improve the accurac...

  18. Spine revisited: Principles and parlance redefined

    Directory of Open Access Journals (Sweden)

    Kothari M

    2005-01-01

    Full Text Available A revised appreciation of the evolution and the nature of bone in general and of vertebrae in particular, allows revisiting the human spine to usher in some new principles and more rational parlance, that embody spine′s phylogeny, ontogeny, anatomy and physiology. Such an approach accords primacy to spine′s soft-tissues, and relegates to its bones a secondary place.

  19. The Actinide Transition Revisited by Gutzwiller Approximation

    Science.gov (United States)

    Xu, Wenhu; Lanata, Nicola; Yao, Yongxin; Kotliar, Gabriel

    2015-03-01

    We revisit the problem of the actinide transition using the Gutzwiller approximation (GA) in combination with the local density approximation (LDA). In particular, we compute the equilibrium volumes of the actinide series and reproduce the abrupt change of density found experimentally near plutonium as a function of the atomic number. We discuss how this behavior relates with the electron correlations in the 5 f states, the lattice structure, and the spin-orbit interaction. Our results are in good agreement with the experiments.

  20. BHQ revisited (2): Texture development

    Science.gov (United States)

    Kilian, Rüdiger; Heilbronner, Renée

    2016-04-01

    appears that grains can be unfavourably oriented for glide despite their c-axis direction falling in those positions which were used in the "classical" interpretation. Additionally, it turns out that grain-scale dispersion axes can be used to describe the kinematic behaviour in a more consistent way compared to the rotations axes obtained from intragranular misorientations in the range of 2-10°. The implications derived from the experimental data set will be compared to data obtained from natural quartz mylonites which formed in a comparable recrystallization regime. This is the companion poster to "BHQ revisited (I) looking at grain size" where the development of the dynamically recrystallized grain size is addressed. Reference cited: Heilbronner, R., and J. Tullis (2006), Evolution of c axis pole figures and grain size during dynamic recrystallization: Results from experimentally sheared quartzite, J. Geophys. Res., 111, B10202, doi:10.1029/2005JB004194.

  1. PAT tools for fermentation processes

    DEFF Research Database (Denmark)

    Gernaey, Krist

    to summarize process knowledge, to support experimental work, and also within design of PAT systems - Small-scale equipment for high-throughput experimentation, a field which has been researched intensively during the past decade The presentation ends with a short perspective on future developments......The publication of the Process Analytical Technology (PAT) guidance has been one of the most important milestones for pharmaceutical production during the past ten years. The ideas outlined in the PAT guidance are also applied in other industries, for example the fermentation industry. Process...... knowledge is central in PAT projects. This presentation therefore gives a brief overview of a number of PAT tools for collecting process knowledge on fermentation processes: - On-line sensors, where for example spectroscopic measurements are increasingly applied - Mechanistic models, which can be used...

  2. Pesticides' influence on wine fermentation.

    Science.gov (United States)

    Caboni, Pierluigi; Cabras, Paolo

    2010-01-01

    Wine quality strongly depends on the grape quality. To obtain high-quality wines, it is necessary to process healthy grapes at the correct ripeness stage and for this reason the farmer has to be especially careful in the prevention of parasite attacks on the grapevine. The most common fungal diseases affecting grape quality are downy and powdery mildew (Plasmopara viticola and Uncinula necator), and gray mold (Botrytis cinerea). On the other hand, the most dangerous insects are the grape moth (Lobesia botrana), vine mealybug (Planococcus ficus), and the citrus mealybug (Planococcus citri). Farmers fight grape diseases and insects applying pesticides that can be found at harvest time on grapes. The persistence of pesticides depends on the chemical characteristic of the active ingredients as well as on photodegradation, thermodegradation, codistillation, and enzymatic degradation. The pesticide residues on grapes can be transferred to the must and this can influence the selection and development of yeast strains. Moreover, yeasts can also influence the levels of the pesticides in the wine by reducing or adsorbing them on lees. During the fermentative process, yeasts can cause the disappearance of pesticide residues by degradation or absorption at the end of the fermentation when yeasts are deposited as lees. In this chapter, we reviewed the effect of commonly used herbicides, insecticides, and fungicides on yeasts. We also studied the effect of alcoholic and malolactic fermentation on pesticide residues.

  3. Pesticides' influence on wine fermentation.

    Science.gov (United States)

    Caboni, Pierluigi; Cabras, Paolo

    2010-01-01

    Wine quality strongly depends on the grape quality. To obtain high-quality wines, it is necessary to process healthy grapes at the correct ripeness stage and for this reason the farmer has to be especially careful in the prevention of parasite attacks on the grapevine. The most common fungal diseases affecting grape quality are downy and powdery mildew (Plasmopara viticola and Uncinula necator), and gray mold (Botrytis cinerea). On the other hand, the most dangerous insects are the grape moth (Lobesia botrana), vine mealybug (Planococcus ficus), and the citrus mealybug (Planococcus citri). Farmers fight grape diseases and insects applying pesticides that can be found at harvest time on grapes. The persistence of pesticides depends on the chemical characteristic of the active ingredients as well as on photodegradation, thermodegradation, codistillation, and enzymatic degradation. The pesticide residues on grapes can be transferred to the must and this can influence the selection and development of yeast strains. Moreover, yeasts can also influence the levels of the pesticides in the wine by reducing or adsorbing them on lees. During the fermentative process, yeasts can cause the disappearance of pesticide residues by degradation or absorption at the end of the fermentation when yeasts are deposited as lees. In this chapter, we reviewed the effect of commonly used herbicides, insecticides, and fungicides on yeasts. We also studied the effect of alcoholic and malolactic fermentation on pesticide residues. PMID:20610173

  4. NaCl-Added Soybean Fermentation and Post-Fermentation Moisture Modulation

    NARCIS (Netherlands)

    Rakshit, M.; Nout, M.J.R.; Sarkar, P.K.

    2015-01-01

    The present study aimed to evaluate the effect of adding NaCl prior to fermentation and moisture reduction after the fermentation on the safety and shelf life of kinema, a Bacillus-fermented soybean food. The physicochemical parameters of kinema decreased with an increase in the concentration of NaC

  5. Fluidized Bed Reactor as Solid State Fermenter

    Directory of Open Access Journals (Sweden)

    Krishnaiah, K.

    2005-01-01

    Full Text Available Various reactors such as tray, packed bed, rotating drum can be used for solid-state fermentation. In this paper the possibility of fluidized bed reactor as solid-state fermenter is considered. The design parameters, which affect the performances are identified and discussed. This information, in general can be used in the design and the development of an efficient fluidized bed solid-state fermenter. However, the objective here is to develop fluidized bed solid-state fermenter for palm kernel cake conversion into enriched animal and poultry feed.

  6. Microbial fermented tea - a potential source of natural food preservatives

    NARCIS (Netherlands)

    Mo, H.Z.; Yang Zhu, Yang; Chen, Z.M.

    2008-01-01

    Antimicrobial activities of microbial fermented tea are much less known than its health beneficial properties. These antimicrobial activities are generated in natural microbial fermentation process with tea leaves as substrates. The antimicrobial components produced during the fermentation process h

  7. Fermented Meat Products%发酵肉制品

    Institute of Scientific and Technical Information of China (English)

    凌静

    2008-01-01

    This article introduced the types,characteristics of the fermented meat product and the research situation of the domestic and foreign fermented meat product.It also indicated the developing prospect of the fermented meat products.

  8. Microbial biotechnology.

    Science.gov (United States)

    Demain, A L

    2000-01-01

    For thousands of years, microorganisms have been used to supply products such as bread, beer and wine. A second phase of traditional microbial biotechnology began during World War I and resulted in the development of the acetone-butanol and glycerol fermentations, followed by processes yielding, for example, citric acid, vitamins and antibiotics. In the early 1970s, traditional industrial microbiology was merged with molecular biology to yield more than 40 biopharmaceutical products, such as erythropoietin, human growth hormone and interferons. Today, microbiology is a major participant in global industry, especially in the pharmaceutical, food and chemical industries. PMID:10631778

  9. Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Progress report, June 1-August 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.I.C.; Cooney, C.L.; Demain, A.L.; Gomez, R.F.; Sinskey, A.J.

    1978-08-01

    Studies concerning the cellobiose properties of Clostridium thermocellum were started to determine if the cellulose degradation end products can be enhanced for glucose (with a subsequent decrease in cellobiose). Implications of preliminary studies indicate that the cells or the enzyme(s) responsible for converting cellobiose to glucose can be manipulated environmentally and genetically to increase the final yield of glucose. The second area of effort is to the production of chemical feedstocks. Three fermentations have been identified for exploration. Preliminary reports on acrylic acid acetone/butanol, and acetic acid production by C. propionicum, C. acetobutylicum, and C. thermoaceticum, respectively, are included. (DMC)

  10. Capturing the response of Clostridium acetobutylicum to chemical stressors using a regulated genome-scale metabolic model

    International Nuclear Information System (INIS)

    Clostridia are anaerobic Gram-positive Firmicutes containing broad and flexible systems for substrate utilization, which have been used successfully to produce a range of industrial compounds. Clostridium acetobutylicum has been used to produce butanol on an industrial scale through acetone-butanol-ethanol (ABE) fermentation. A genome-scale metabolic (GSM) model is a powerful tool for understanding the metabolic capacities of an organism and developing metabolic engineering strategies for strain development. The integration of stress related specific transcriptomics information with the GSM model provides opportunities for elucidating the focal points of regulation

  11. Utilization of economical substrate-derived carbohydrates by solventogenic clostridia: pathway dissection, regulation and engineering.

    Science.gov (United States)

    Gu, Yang; Jiang, Yu; Yang, Sheng; Jiang, Weihong

    2014-10-01

    Solventogenic clostridia can produce acetone, butanol and ethanol (ABE) by using different carbohydrates. For economical reasons, the utilization of cheap and renewable biomass in clostridia-based ABE fermentation has recently attracted increasing interests. With the study of molecular microbiology and development of genetic tools, the understanding of carbohydrate metabolism in clostridia has increased in recent years. Here, we review the pioneering work in this field, with a focus on dissecting the pathways and describing the regulation of the metabolism of economical substrate-derived carbohydrates by clostridia. Recent progress in the metabolic engineering of carbohydrate utilization pathways is also described.

  12. Chemicals from biomass - BioForest

    Energy Technology Data Exchange (ETDEWEB)

    Heiningen, A. van (Aalto University School of Chemical Technology, Espoo (Finland), Dept. of Forest Products Technology), e-mail: adriaan.vanheiningen@aalto.fi; Granstroem, T. (Aalto University School of Chemical Technology, Espoo (Finland), Dept.of Biotechnology and Chemical Technology), e-mail: tom.granstrom@aalto.fi

    2011-11-15

    The objective of the BioForest project is to develop the science and technology of a series of integrated processing steps which economically convert mixed hardwood and softwood biomass and recycled fibers into commodity chemicals at an existing forest products complex which also produces wood and/or pulp and paper. The commodity products will be produced from the biomass carbohydrates using a novel biomass fractionation process, a modified ABE (Acetone- Butanol-Ethanol) fermentation process, and a novel continuous solvent recovery method from the fermentation liquid. The mixture of solvents produced by the modified ABE process consists of isopropanol, butanol and ethanol. The key technological barriers which have been accomplished in the Bioforest project are following: 1. Fundamental understanding of the kinetics of delignification, hemicellulose dissolution and cellulose degradation during SEW fractionation of softwood and hardwood 2. Optimization of SEW fractionation of softwood biomass with a total treatment time as short as 30 minutes 3. Simultaneous SEW fractionation of hardwood and softwood biomass 4. Production of a high concentration (> 100 g/L) hemicellulose monosugar solution from SEW spent fractionation liquor at a sugar yield larger than 85% by multistep conditioning 5. Construction of E.coli strain harboring isopropanol dehydrogenase gene capable of acetone conversion to isopropanol 6. Successful fermentation of the conditioned hemicellulose monosugar solution to ABE (Acetone, Butanol, Ethanol) solvents using advanced column technology (patent pending) or semi-solid pulp fermentations with the volumetric productivities of 5.5 and 13.5 g/L h respectively. (orig.)

  13. Kinetics model development of cocoa bean fermentation

    Science.gov (United States)

    Kresnowati, M. T. A. P.; Gunawan, Agus Yodi; Muliyadini, Winny

    2015-12-01

    Although Indonesia is one of the biggest cocoa beans producers in the world, Indonesian cocoa beans are oftenly of low quality and thereby frequently priced low in the world market. In order to improve the quality, adequate post-harvest cocoa processing techniques are required. Fermentation is the vital stage in series of cocoa beans post harvest processing which could improve the quality of cocoa beans, in particular taste, aroma, and colours. During the fermentation process, combination of microbes grow producing metabolites that serve as the precursors for cocoa beans flavour. Microbial composition and thereby their activities will affect the fermentation performance and influence the properties of cocoa beans. The correlation could be reviewed using a kinetic model that includes unstructured microbial growth, substrate utilization and metabolic product formation. The developed kinetic model could be further used to design cocoa bean fermentation process to meet the expected quality. Further the development of kinetic model of cocoa bean fermentation also serve as a good case study of mixed culture solid state fermentation, that has rarely been studied. This paper presents the development of a kinetic model for solid-state cocoa beans fermentation using an empirical approach. Series of lab scale cocoa bean fermentations, either natural fermentations without starter addition or fermentations with mixed yeast and lactic acid bacteria starter addition, were used for model parameters estimation. The results showed that cocoa beans fermentation can be modelled mathematically and the best model included substrate utilization, microbial growth, metabolites production and its transport. Although the developed model still can not explain the dynamics in microbial population, this model can sufficiently explained the observed changes in sugar concentration as well as metabolic products in the cocoa bean pulp.

  14. The Faraday effect revisited: General theory

    DEFF Research Database (Denmark)

    Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm

    2006-01-01

    This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. At zero temperature and zero frequency......, if the Fermi energy lies in a spectral gap, we rigorously prove theWidom-Streda formula. For free electrons, the transverse conductivity can be explicitly computed and coincides with the classical result. In the general case, using magnetic perturbation theory, the conductivity tensor is expanded in powers...

  15. Polynomial chaotic inflation in supergravity revisited

    Directory of Open Access Journals (Sweden)

    Kazunori Nakayama

    2014-10-01

    Full Text Available We revisit a polynomial chaotic inflation model in supergravity which we proposed soon after the Planck first data release. Recently some issues have been raised in Ref. [12], concerning the validity of our polynomial chaotic inflation model. We study the inflaton dynamics in detail, and confirm that the inflaton potential is very well approximated by a polynomial potential for the parameters of our interest in any practical sense, and in particular, the spectral index and the tensor-to-scalar ratio can be estimated by single-field approximation. This justifies our analysis of the polynomial chaotic inflation in supergravity.

  16. Coccolithophorids in polar waters: Pappomonas spp. revisited

    DEFF Research Database (Denmark)

    Thomsen, Helge Abildhauge; Østergaard, J.B.

    2014-01-01

    A contingent of weakly calcified coccolithophorid genera and species were described from polar regions almost 40 years ago. In the interim period a few additional findings have been reported enlarging the realm of some of the species. The genus Pappomonas is revisited here with the purpose...... of providing, based on additional sampling from both polar regions, an update on species morphology, life history aspects and biogeography that can serve as a reference for the future. The examination of a substantial number of cells unequivocally supports the elevation to species level of P. borealis stat...

  17. Coccolithophorids in polar waters: Trigonaspis spp. revisited

    DEFF Research Database (Denmark)

    Thomsen, Helge Abildhauge; Østergaard, Jette B.

    2015-01-01

    A group of weakly calcified coccolithophorid genera and species were described from polar regions several decades ago. In the interim period a few additional findings have been reported adding to the morphological and biogeographical databases of some of the species. The holococcolithophorid genus...... Trigonaspis is revisited here with the purpose of providing, based on additional sampling from both polar regions, an update on species morphology, life history aspects and biogeography. The genus Trigonaspis as currently circumscribed comprises four taxa – two from each polar region. The triangular plates...

  18. Sloan Digital Sky Survey Photometric Calibration Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Marriner, John; /Fermilab

    2012-06-29

    The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recomputed and compared to synthetic magnitudes computed from measured filter bandpasses.

  19. Resolution of Reflection Seismic Data Revisited

    DEFF Research Database (Denmark)

    Hansen, Thomas Mejer; Mosegaard, Klaus; Zunino, Andrea

    wavelength of the wavelet within the thin layer. Using a simple thin-layer parameterization Widess (1973) demonstrated that thin layers with thickness less that around λb/8 cannot be resolved from seismic data independent of the noise level. This has results since been widely adopted as a commonly accepted...... lower vertical resolution of reflection seismic data. In the following we will revisit think layer model and demonstrate that there is in practice no limit to the vertical resolution using the parameterization of Widess (1973), and that the vertical resolution is limited by the noise in the data...

  20. Revisiting Fermat's Factorization for the RSA Modulus

    CERN Document Server

    Gupta, Sounak

    2009-01-01

    We revisit Fermat's factorization method for a positive integer $n$ that is a product of two primes $p$ and $q$. Such an integer is used as the modulus for both encryption and decryption operations of an RSA cryptosystem. The security of RSA relies on the hardness of factoring this modulus. As a consequence of our analysis, two variants of Fermat's approach emerge. We also present a comparison between the two methods' effective regions. Though our study does not yield a new state-of-the-art algorithm for integer factorization, we believe that it reveals some interesting observations that are open for further analysis.

  1. Re-visiting the Piper Alpha accident

    OpenAIRE

    Dykesteen, Mette Kahrs

    2013-01-01

    The main objective of this thesis has been to re-visit the Piper Alpha accident using the latest version of the FLACS simulation code. In 1988/89 simulations of the gas explosion in the C Module of Piper Alpha were performed by Jan Roar Bakke and Idar Storvik at Christian Michelsen Institute, in conjunction with the investigation after the accident. For these simulations the computer code FLACS was used [1, 2]. In this thesis, the same simulation cases have been looked into, and the results o...

  2. Sloan Digital Sky Survey Photometric Calibration Revisited

    Science.gov (United States)

    Marriner, J.

    2016-05-01

    The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recomputed and compared to synthetic magnitudes computed from measured filter bandpasses.

  3. Energy balance in solid state fermentation processes

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L.J.A.; Torres, A.; Echevarria, J.; Saura, G. (Instituto Cubano de Investigaciones de los Derivados de la Cana de Azucar (ICIDCA), La Habana (Cuba))

    1991-01-01

    It was applied a macroscopic energy balance to a solid state fermentation process and an electron balance in order to estimate the temperature and the heat evolved in the process. There were employed several equations that describe the development of the system and offer the possibility to design or control such fermentations. (orig.).

  4. Solid state fermentation for foods and beverages

    NARCIS (Netherlands)

    Chen, J.; Zhu, Y.; Nout, M.J.R.; Sarkar, P.K.

    2013-01-01

    The book systematically describes the production of solid-state fermented food and beverage in terms of the history and development of SSF technology and SSF foods, bio-reactor design, fermentation process, various substrate origins and sustainable development. It emphasizes Oriental traditional foo

  5. Recent advances in fermentative biohydrogen production

    Institute of Scientific and Technical Information of China (English)

    Xuemei Liu; Nanqi Ren; Funan Song; Chuanping Yang; Aijie Wang

    2008-01-01

    Hydrogen energy, as a kind of clean energy with great potential, has been a hotspot for study worldwide. Based on the recent research on biohydrogen production, this paper gives a brief review on the following aspects: fermentative hydrogen production process and the engineering control statagy, key factors affecting the efficiency of hydrogen production, such as substrates, cysteine, metal ions, anaerobic fermentation terminal products, and formic acid and ammonia. Moreover, anaerobic fermentative hydrogen-producing strain and regulation and control of enzyme gene in fermentative hydrogen production are also discussed. Finally, the prospect of anaerobic fermentative biohydrogen production is proposed in three study areas, namely developing new techniques for breeding hydrogen-producing bacteria, exploitations of more strains and gene resources, and intensifying the application of microbial molecular breeding in hydrogen production.

  6. Lactic acid fermentation of crude sorghum extract

    Energy Technology Data Exchange (ETDEWEB)

    Samuel, W.A.; Lee, Y.Y.; Anthony, W.B.

    1980-04-01

    Crude extract from sweet sorghum supplemented with vetch juice was utilized as the carbohydrate source for fermentative production of lactic acid. Fermentation of media containing 7% (w/v) total sugar was completed in 60-80 hours by Lactobacillus plantarum, product yield averaging 85%. Maximum acid production rates were dependent on pH, initial substrate distribution, and concentration, the rates varying from 2 to 5 g/liter per hour. Under limited medium supplementation the lactic acid yield was lowered to 67%. The fermented ammoniated product contained over eight times as much equivalent crude protein (N x 6.25) as the original medium. Unstructured kinetic models were developed for cell growth, lactic acid formation, and substrate consumption in batch fermentation. With the provision of experimentally determined kinetic parameters, the proposed models accurately described the fermentation process. 15 references.

  7. FERMENTED MILK AS A FUNCTIONAL FOOD

    Directory of Open Access Journals (Sweden)

    Irena Rogelj

    2000-06-01

    Full Text Available Certain foods have been associated with health benefits for many years; fermented milks and yoghurt are typical examples. The health properties of these dairy products were a part of folklore until the concept of probiotics emerged, and the study of fermented milks and yoghurt containing probiotic bacteria has become more systematic. Functional foods have thus developed as a food, or food ingredient, with positive effects on host health and/or well-being beyond their nutritional value, and fermented milk with probiotic bacteria has again become the prominent representative of this new category of food. Milk alone is much more than the sum of its nutrients. It contains an array of bioactivities: modulating digestive and gastrointestinal functions, haemodynamics, controlling probiotic microbial growth, and immunoregulation. When fermented milk is enriched with probiotic bacteria and prebiotics it meets all the requirements of functional food. The possible positive effects of enriched fermented milk on host health will be reviewed.

  8. Functional genomics for food fermentation processes.

    Science.gov (United States)

    Smid, E J; Hugenholtz, J

    2010-01-01

    This review describes recent scientific and technological drivers of food fermentation research. In addition, a number of practical implications of the results of this development will be highlighted. The first part of the manuscript elaborates on the message that genome sequence information gives us an unprecedented view on the biodiversity of microbes in food fermentation. This information can be made applicable for tailoring relevant characteristics of food products through fermentation. The second part deals with the integration of genome sequence data into metabolic models and the use of these models for a number of topics that are relevant for food fermentation processes. The final part will be about metagenomics approaches to reveal the complexity and understand the functionality of undefined complex microbial consortia used in a diverse range of food fermentation processes.

  9. Ground Zero revisits shape outbreaks: Zika and beyond

    CERN Document Server

    Manrique, Pedro D; Johnson, Neil F

    2016-01-01

    During an infection outbreak, many people continue to revisit Ground Zero - such as the one square mile of Miami involved in the current Zika outbreak- for work, family or social reasons. Public health planning must account for the counterintuitive ways in which this human flow affects the outbreak's duration, severity and time-to-peak. Managing this flow of revisits can allow the outbreak's evolution to be tailored.

  10. The role of brand destination experience in determining revisit intention

    DEFF Research Database (Denmark)

    Mattsson, Jan; Barnes, Stuart; Sørensen, Flemming

    experience, which provides a more holistic and unified view of the brand destination. The research uses a logistic regression model to determine the role of satisfaction and brand experience in determining revisit intentions. The study also examines differences among subgroups and four brand experience sub......-constructs. The findings suggest that brand experience is an important determinant of revisit intentions, but that there is variation among respondent groups. The paper rounds off with conclusions and implications for research and practice....

  11. Biohydrogen production from soluble condensed molasses fermentation using anaerobic fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Lay, Chyi-How; Lin, Chiu-Yue [Department of Environmental Engineering and Science, Feng Chia University, Taichung 40724 (China); Wu, Jou-Hsien; Hsiao, Chin-Lang [Department of Water Resource Engineering, Feng Chia University (China); Chang, Jui-Jen [Department of Life Sciences, National Chung Hsing University (China); Chen, Chin-Chao [Environmental Resources Laboratory, Department of Landscape Architecture, Chungchou Institute of Technology (China)

    2010-12-15

    Using anaerobic micro-organisms to convert organic waste to produce hydrogen gas gives the benefits of energy recovery and environmental protection. The objective of this study was to develop a biohydrogen production technology from food wastewater focusing on hydrogen production efficiency and micro-flora community at different hydraulic retention times. Soluble condensed molasses fermentation (CMS) was used as the substrate because it is sacchariferous and ideal for hydrogen production. CMS contains nutrient components that are necessary for bacterial growth: microbial protein, amino acids, organic acids, vitamins and coenzymes. The seed sludge was obtained from the waste activated sludge from a municipal sewage treatment plant in Central Taiwan. This seed sludge was rich in Clostridium sp. A CSTR (continuously stirred tank reactor) lab-scale hydrogen fermentor (working volume, 4.0 L) was operated at a hydraulic retention time (HRT) of 3-24 h with an influent CMS concentration of 40 g COD/L. The results showed that the peak hydrogen production rate of 390 mmol H{sub 2}/L-d occurred at an organic loading rate (OLR) of 320 g COD/L-d at a HRT of 3 h. The peak hydrogen yield was obtained at an OLR of 80 g COD/L-d at a HRT of 12 h. At HRT 8 h, all hydrogenase mRNA detected were from Clostridium acetobutylicum-like and Clostridium pasteurianum-like hydrogen-producing bacteria by RT-PCR analysis. RNA based hydrogenase gene and 16S rRNA gene analysis suggests that Clostridium exists in the fermentative hydrogen-producing system and might be the dominant hydrogen-producing bacteria at tested HRTs (except 3 h). The hydrogen production feedstock from CMS is lower than that of sucrose and starch because CMS is a waste and has zero cost, requiring no added nutrients. Therefore, producing hydrogen from food wastewater is a more commercially feasible bioprocess. (author)

  12. Prebiotics in piglet nutrition? Fermentation kinetics along the GI tract

    NARCIS (Netherlands)

    Awati, A.A.

    2005-01-01

    Keywords: fermentation, gas production, pigletsThe generalized theory behind the carbohydrate to protein fermentation in the GIT is that in presence of fermentable carbohydrate substrate, microbes prefer to ferment carbohydrate source to derive energy and use the nitrogen available for their own gro

  13. Researchers foment better ways to ferment

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-01

    Researchers in Australia and the US are experimenting with Zymomonas mobilis, the bacteria strain used to make tequila. It could reduce fermentation times because it can withstand substantially higher temperatures than yeast. MIT is experimenting with Clostridium thermocellum, a bacteria strain which has the ability to hydrolyze cellulose into glucose sugar and simultaneously ferment the glucose to ethanol. Purdue University is working with Rhizopus, used in the fermentation of certain Chinese wines where alcohol content approaches 18%. Other researchers are looking at enzyme-based processes to improve sugar yields from starch and cellulose, and Purdue is making a major effort to cut distillation energy consumption.

  14. Integrated product formation and recovery in fermentation.

    Science.gov (United States)

    van der Wielen, L A; Luyben, K C

    1992-04-01

    Fermentation processes are hampered by a variety of problems originating from the accumulation of products in the fermenter. Integration of fermentation and a primary product separation step can accelerate the product formation, improve the product yield, and facilitate downstream processing. The advantages of integrated bioprocesses, however, are counteracted by the incompatibility of the subprocesses. Over the past few years, research in this field has been directed towards the development of engineering tools to reduce integration problems, to select a suitable approach, and to predict the feasibility of the integrated process. More fundamental knowledge about metabolic pathways, control mechanisms, and process dynamics is needed in order to optimally design integrated systems. PMID:1368288

  15. Biotechnology of Flavor Generation in Fermented Meats

    Science.gov (United States)

    Toldrá, Fidel

    Traditionally, meat fermentation was based on the use of natural flora, including the “back-slopping”, or addition of a previous successful fermented sausage. However, these practices gave a great variability in the developed flora and affected the safety and quality of the sausages (Toldrá, 2002; Toldrá & Flores, 2007). The natural flora of fermented meat has been studied for many years (Leistner, 1992; Toldrá, 2006a), and more recently, these micro-organisms have been isolated and biochemically identified through molecular methods applied to extracted DNA and RNA (Cocolin, Manzano, Aggio, Cantoni, & Comi, 2001; Cocolin, Manzano, Cantoni, & Comi, 2001; Comi, Urso, Lacumin, Rantsiou, Cattaneo & Cantoni, 2005).

  16. Microbiological and biochemical study of coffee fermentation.

    Science.gov (United States)

    Avallone, S; Guyot, B; Brillouet, J M; Olguin, E; Guiraud, J P

    2001-04-01

    The coffee fermentation microflora were rich and mainly constituted of aerobic Gram-negative bacilli, with Erwinia and Klebsiella genuses at the highest frequencies. The best population increase was observed with lactic acid bacteria and yeasts, whereas those microorganisms that counted on a pectin medium remained constant during the fermentation step. Qualitatively, lactic acid bacteria belonged mainly to Leuconostoc mesenteroides species but the others microflora were relatively heterogeneous. The microorganisms isolated on pectin medium were Enterobacteriaceae, identified as Erwinia herbicola and Klebsiella pneumoniae, not reported as strong pectolytic strains. Throughout coffee fermentation, 60% of the simple sugars were degraded by the total microflora and not specifically by pectolytic microorganisms. PMID:11178725

  17. Quality and Flavor Profiles of Arabica Coffee Processed by Some Fermentation Treatments: Temperature, Containers, and Fermentation Agents Addition

    Directory of Open Access Journals (Sweden)

    Yusianto .

    2013-12-01

    Full Text Available Coffee fermentation is a step of wet processing. In fact, some microorganisms naturally exist on the surface of coffee cherry. Using a starter culture of microorganisms may change equilibrium of microorganism population. Among some safe fermentation agents are present in “ragi tape” (yeast, “ragi tempe”, and fermented milk. A fermentor machine equipped with eating-control and stirrer had been designed, and tested before. Some treatments investigated were fermentation containers (fermentor machine and plastic sacks; fermentation agents (fresh cage-luwakcoffee, “ragi tape”, “ragi tempe”, and fermented milk; temperature of fermentation (room, 30 C, 35 C, and 40 C; and duration of fermentation (6, 12, and 18 hours. The experiment were replicated three times. Wet-coffee parchments were washed and sundried until moisture content reached 12%. The dried parchment was hulled and examined for the bean quality and flavors. The experiment indicated that 40 C fermentation in fermentor machine resulted in higher content of “full sour defect”. Fermentation agents significanly influenced bean size. Temperature treatment significanly influenced bulk density and bean size. The best flavor profile was obtained from fermentation in plastic sack at ambient temperature. Bacteria of fermented milk and “fresh luwak coffee” as fermentation agents resulted up to excellent flavor. Twelve hours fermentation produced best flavor of Arabica coffee compared to 6 and 18 hours. Key words: Arabica coffee, fermentation, flavour, fermentation agents

  18. Novel Method of Lactic Acid Production by Electrodialysis Fermentation

    OpenAIRE

    Hongo, Motoyoshi; Nomura, Yoshiyuki; Iwahara, Masayoshi

    1986-01-01

    In lactic acid fermentation by Lactobacillus delbrueckii, the produced lactic acid affected the lactic acid productivity. Therefore, for the purpose of alleviating this inhibitory effect, an electrodialysis fermentation method which can continuously remove produced lactic acid from the fermentation broth was applied to this fermentation process. As a result, the continuation of fermentation activity was obtained, and the productivity was three times higher than in non-pH-controlled fermentati...

  19. FERMENTATION ACTIVITY OF LACTOSE-FERMENTATION YEAST IN WHEY-MALT WORT

    Directory of Open Access Journals (Sweden)

    E. V. Greek

    2013-04-01

    Full Text Available The main parameters of fermentation of whey-malt wort with the use of different strains of lactose-fermentation yeast was investigated experimentally. According to the findings of investigation of fermentive activity for different types of lactose-fermentation microorganisms in whey-malt wort it was found that the most active spirituous fermentation for all parameters was in wort fermented by microorganisms Zygosaccharomyces lactis 868-K and Saccharomyces lactis 95. High capacity for utilization of malt carbohydrates represented by easily metabolized carbohydrates of malt extract was determined. Also organoleptic analysis of fermented whey drinks derived from the renewed mixtures of dry whey and fermented malt and yeast Zygosaccharomyces lactis 868-K and Saccharomyces lactis 95 was carried out. It was found that the drink fermented with yeast Zygosaccharomyces lactis 868-K had intense refreshing flavor of rye bread with fruit tones. Intensity growth of aromatization for complex of sample with microorganisms Saccharomyces lactis 95, indicating high organoleptic indexes of the drink was observed.

  20. Post-Inflationary Gravitino Production Revisited

    CERN Document Server

    Ellis, John; Nanopoulos, Dimitri V; Olive, Keith A; Peloso, Marco

    2016-01-01

    We revisit gravitino production following inflation. As a first step, we review the standard calculation of gravitino production in the thermal plasma formed at the end of post-inflationary reheating when the inflaton has completely decayed. Next we consider gravitino production prior to the completion of reheating, assuming that the inflaton decay products thermalize instantaneously while they are still dilute. We then argue that instantaneous thermalization is in general a good approximation, and also show that the contribution of non-thermal gravitino production via the collisions of inflaton decay products prior to thermalization is relatively small. Our final estimate of the gravitino-to-entropy ratio is approximated well by a standard calculation of gravitino production in the post-inflationary thermal plasma assuming total instantaneous decay and thermalization at a time $t \\simeq 1.2/\\Gamma_\\phi$. Finally, in light of our calculations, we consider potential implications of upper limits on the gravitin...

  1. Revisiting gravitino dark matter in thermal leptogenesis

    CERN Document Server

    Ibe, Masahiro; Yanagida, Tsutomu T

    2016-01-01

    In this paper, we revisit the gravitino dark matter scenario in the presence of the bilinear $R$-parity violating interaction. In particular, we discuss a consistency with the thermal leptogenesis. For a high reheating temperature required for the thermal leptogenesis, the gravitino dark matter tends to be overproduced, which puts a severe upper limit on the gluino mass. As we will show, a large portion of parameter space of the gravitino dark matter scenario has been excluded by combining the constraints from the gravitino abundance and the null results of the searches for the superparticles at the LHC experiments. In particular, the models with the stau (and other charged slepton) NLSP has been almost excluded by the searches for the long-lived charged particles at the LHC unless the required reheating temperature is somewhat lowered by assuming, for example, a degenerated right-handed neutrino mass spectrum.

  2. Revisiting the R νMDM models

    Science.gov (United States)

    Cai, Yi; Schmidt, Michael A.

    2016-05-01

    Combining neutrino mass generation and a dark matter candidate in a unified model has always been intriguing. We revisit the class of R νMDM models, which incorporate minimal dark matter in radiative neutrino mass models based on the one-loop ultraviolet completions of the Weinberg operator. The possibility of an exact accidental Z 2 is completely ruled out in this scenario. We study the phenomenology of one of the models with an approximate Z 2 symmetry. In addition to the Standard Model particles, it contains two real scalar quintuplets, one vector-like quadruplet fermion and a fermionic quintuplet. The neutral component of the fermionic quintuplet serves as a good dark matter candidate which can be tested by the future direct and indirect detection experiments. The constraints from flavor physics and electroweak-scale naturalness are also discussed.

  3. ADHM Revisited: Instantons and Wilson Lines

    CERN Document Server

    Tong, David

    2014-01-01

    We revisit the well-studied D0-D4 system of D-branes and its relationship to the ADHM construction. It is well known that the D0-branes appear as instantons in the D4-brane worldvolume. We add a Wilson line to the D4-brane in the guise of an extended fundamental string and determine how this affects the D0-brane dynamics. As the D0-brane moves in the presence of the Wilson line, it experiences a Lorentz force, proportional to its Yang-Mills gauge connection. From the perspective of the D0-brane quantum mechanics, this force emerges through the ADHM construction of the self-dual gauge connection.

  4. Three dimensional maximally supersymmetric field theory revisited

    International Nuclear Information System (INIS)

    The field theoretical realization of maximally extended supersymmetry algebra in 3 dimensions is revisited here. The existence of an interacting field theory which also manifests the full automorphism demands the existence of extra global symmetry transformations. They form the infinite-dimensional group of volume-preserving diffeomorphisms of an internal 3-dimensional space. Upon regularization, it will be truncated to a finite-dimensional unitary group. This extra symmetry together with multiplicity of component fields allow one to consistently introduce self-interactions through Nambu brackets or matrix 4-commutators. It turns out that there exists a conformal field theory which is invariant under OSp(4 | 8) x U(N) groups of global transformations. Relaxing full automorphism to its biggest subgroup, one can consistently mass-deforms the theory. In addition to ordinary associative algebraic structures, a non-associative structure also underlies this theory. (author)

  5. Revisiting instanton corrections to the Konishi multiplet

    CERN Document Server

    Alday, Luis F

    2016-01-01

    We revisit the calculation of instanton effects in correlation functions in ${\\cal N}=4$ SYM involving the Konishi operator and operators of twist two. Previous studies revealed that the scaling dimensions and the OPE coefficients of these operators do not receive instanton corrections in the semiclassical approximation. We go beyond this approximation and demonstrate that, while operators belonging to the same ${\\cal N}=4$ supermultiplet ought to have the same conformal data, the evaluation of quantum instanton corrections for one operator can be mapped into a semiclassical computation for another operator in the same supermultiplet. This observation allows us to compute explicitly the leading instanton correction to the scaling dimension of operators in the Konishi supermultiplet as well as to their structure constants in the OPE of two half-BPS scalar operators. We then use these results, together with crossing symmetry, to determine instanton corrections to scaling dimensions of twist-four operators with ...

  6. The Species Problem in Myxomycetes Revisited.

    Science.gov (United States)

    Walker, Laura M; Stephenson, Steven L

    2016-08-01

    Species identification in the myxomycetes (plasmodial slime molds or myxogastrids) poses particular challenges to researchers as a result of their morphological plasticity and frequent alteration between sexual and asexual life strategies. Traditionally, myxomycete morphology has been used as the primary method of species delimitation. However, with the increasing availability of genetic information, traditional myxomycete taxonomy is being increasingly challenged, and new hypotheses continue to emerge. Due to conflicts that sometimes occur between traditional and more modern species concepts that are based largely on molecular data, there is a pressing need to revisit the discussion surrounding the species concept used for myxomycetes. Biological diversity is being increasingly studied with molecular methods and data accumulates at ever-faster rates, making resolution of this matter urgent. In this review, currently used and potentially useful species concepts (biological, morphological, phylogenetic and ecological) are reviewed, and an integrated approach to resolve the myxomycete species problem is discussed. PMID:27351595

  7. Revisiting light neutralino scenarios in the MSSM

    CERN Document Server

    Vasquez, Daniel Albornoz; Boehm, Celine

    2011-01-01

    We revisit the case of a light neutralino LSP in the framework of the MSSM. We consider a model with eleven free parameters. We show that all scenarios where the annihilation of light neutralinos rely mainly on the exchange of a light pseudoscalar are excluded by direct detection searches and by Fermi measurements of the gamma-flux from dwarf spheroidal galaxies. On the other hand, we find scenarios with light sleptons that satisfy all collider and astroparticle physics constraints. In this case, the lower limit on the LSP mass is 12.6 GeV. We discuss how the parameter space of the model will be further probed by new physics searches at the LHC.

  8. Seasonal dating of Sappho's 'Midnight Poem' revisited

    Science.gov (United States)

    Cuntz, Manfred; Gurdemir, Levent; George, Martin

    2016-04-01

    Sappho was a Greek lyric poet who composed a significant array of pristine poetry. Although much of it has been lost, her reputation has endured thanks to numerous surviving fragments. One of her contributions includes the so-called 'Midnight Poem', which contains a line about the Pleiades, setting sometime before midnight, and supposedly observed from the island of Lesbos. This poem also refers to the setting of the Moon. Sappho's Midnight Poem thus represents a prime example of where ancient poetry and astronomy merge, and it also offers the possibility of seasonal dating. Previously, Herschberg and Mebius (1990) estimated that the poem was composed in late winter/early spring, a time frame that is not unusual for lyrics of an amorous nature. The aim of our paper is to revisit this earlier finding by using modern-day software. Our study confirms Herschberg and Mebius' result, but also conveys further information.

  9. Seeing the unseen: Charles Bonnet syndrome revisited.

    Science.gov (United States)

    Nair, Aditya Gopinathan; Nair, Akshay Gopinathan; Shah, Bharat R; Gandhi, Rashmin Anilkumar

    2015-09-01

    Charles Bonnet syndrome (CBS) is a rare condition that encompasses three clinical features: complex visual hallucinations, ocular pathology causing visual deterioration, and preserved cognitive status. Common associated ocular pathologies include age-related macular degeneration, glaucoma, and cataracts. Several theories have been proposed to try to explain the visual hallucinations. However, the pathophysiology remains poorly understood, and treatment is largely based on anecdotal data. The lack of awareness of CBS among medical professionals often leads to inappropriate diagnosis and medication. In a country like India, where awareness of mental health is not widespread, cultural myths and stigma prevent patients from seeking professional help. Here we describe two cases of CBS and revisit different ocular morbidities that have been reported to occur in conjunction with CBS. Psychiatrists and ophthalmologists alike must be sensitive to this clinical condition to ensure prompt diagnosis and treatment.

  10. Revisiting Lepton Flavour Universality in B Decays

    CERN Document Server

    Feruglio, Ferruccio; Pattori, Andrea

    2016-01-01

    Lepton flavour universality (LFU) in B-decays is revisited in a model-independent way by considering semileptonic operators defined at a scale Lambda above the electroweak scale v. The importance of quantum effects, so far neglected in the literature, is emphasised. We construct the low-energy effective Lagrangian taking into account the running effects from Lambda down to v through the one-loop renormalization group equations (RGE) in the limit of exact electroweak symmetry and QED RGEs from v down to the 1 GeV scale. The most important quantum effects turn out to be the modification of the leptonic couplings of the vector boson Z and the generation of a purely leptonic effective Lagrangian. Large LFU breaking effects in Z and tau decays and visible lepton flavour violating (LFV) effects in the processes tau -> mu ll, tau -> mu rho, tau -> mu pi and tau -> mu eta^(') are induced.

  11. The Faraday effect revisited: General theory

    DEFF Research Database (Denmark)

    Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm

    conductivity can be explicitly computed and coincides with the classical result. In the general case, using magnetic perturbation theory, the conductivity tensor is expanded in powers of the strength of the magnetic field B. Then the linear term in B of this expansion is written down in terms of the zero......This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. For free electrons, the transverse...... magnetic field Green function and the zero field current operator. In the periodic case, the linear term in B of the conductivity tensor is expressed in terms of zero magnetic field Bloch functions and energies. No derivatives with respect to the quasimomentum appear and thereby all ambiguities are removed...

  12. Degradation of 5-hydroxymethylfurfural during yeast fermentation.

    Science.gov (United States)

    Akıllıoglu, Halise Gül; Mogol, Burçe Ataç; Gökmen, Vural

    2011-12-01

    5-Hydroxymethyl furfural (HMF) may occur in malt in high quantities depending on roasting conditions. However, the HMF content of different types of beers is relatively low, indicating its potential for degradation during fermentation. This study investigates the degradation kinetics of HMF in wort during fermentation by Saccharomyces cerevisiae. The results indicated that HMF decreased exponentially as fermentation progressed. The first-order degradation rate of HMF was 0.693 × 10(-2) and 1.397 × 10(-2)min(-1) for wort and sweet wort, respectively, indicating that sugar enhances the activity of yeasts. In wort, HMF was converted into hydroxymethyl furfuryl alcohol by yeasts with a high yield (79-84% conversion). Glucose and fructose were utilised more rapidly by the yeasts in dark roasted malt than in pale malt (pyeast cells, and presence of sugars in the fermentation medium increases this activity. PMID:22010851

  13. Preparation of Soy Peptides by Liquid Fermentation

    Institute of Scientific and Technical Information of China (English)

    Li Li; Yang Xiaoqun; Zhao Mouming; Liang Shizhong

    2002-01-01

    Many kinds of microorganism canproduce a mount of protease which subsequentlyhydrolysis the protein of the medium into peptideswhen they grow in protein containing liquidmedium. In the present investigation, theconditions of preparing soybean peptides byliquid fermentation were studied following resultswere obtained: (1) SPI is a nice nitrogen sourceand meanwhile an inducible factor of proteaseproduction; its concentration can be as high as3%-4%. (2) Sucrose is the best carbon source;its concentration is 1%-4%. (3) Under theconditions of 28℃, initial pH 60, inoculum size4%, cell age 36hr and fermentation time 24hr-30hr, we can obtain soybean peptides orfermentation liquor with good flavor, its Dhreaches 25%-30% and the yield rate can be ashigh as 75%. (4) Mass spectrograph indicate theMW of the fermentation liquid or the soybeanpeptides mainly distribute at a Dal, theseimply a promising prospect of industrialapplication of submerged fermentation inproducing soybean peptides.

  14. Enzymatic conversion of lignocellulose into fermentable sugars

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Kristensen, Jan Bach; Felby, Claus

    2007-01-01

    The economic dependency on fossil fuels and the resulting effects on climate and environment have put tremendous focus on utilizing fermentable sugars from lignocellulose, the largest known renewable carbohydrate source. The fermentable sugars in lignocellulose are derived from cellulose...... into fermentable sugars requires a number of different cellulases and hemicellulases. The hydrolysis of cellulose is a sequential breakdown of the linear glucose chains, whereas hemicellulases must be capable of hydrolysing branched chains containing different sugars and functional groups. The technology...... issues within pretreatment and hydrolysis remain to be solved. However, significant improvements in yield and cost reductions are expected, thus making large-scale fermentation of lignocellulosic substrates possible. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd...

  15. Fermentation based carbon nanotube bionic functional composites

    OpenAIRE

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique mechanical and physical properties that are not produced by abiotic processes. Based on grape must and bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at r...

  16. Yeast Interactions in Inoculated Wine Fermentation

    OpenAIRE

    Ciani, Maurizio; Capece, Angela; Comitini, Francesca; Canonico, Laura; Siesto, Gabriella; Romano, Patrizia

    2016-01-01

    The use of selected starter culture is widely diffused in winemaking. In pure fermentation, the ability of inoculated Saccharomyces cerevisiae to suppress the wild microflora is one of the most important feature determining the starter ability to dominate the process. Since the wine is the result of the interaction of several yeast species and strains, many studies are available on the effect of mixed cultures on the final wine quality. In mixed fermentation the interactions between the diffe...

  17. Fermentation of lignocellulosic hydrolysates: Inhibition and detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Palmqvist, E.

    1998-02-01

    The ethanol yield and productivity obtained during fermentation of lignocellulosic hydrolysates is decreased due to the presence of inhibiting compounds, such as weak acids, furans and phenolic compounds produced during hydrolysis. Evaluation of the effect of various biological, physical and chemical detoxification treatments by fermentation assays using Saccharomyces cerevisiae was used to characterise inhibitors. Inhibition of fermentation was decreased after removal of the non-volatile compounds, pre-fermentation by the filamentous fungus Trichoderma reesei, treatment with the lignolytic enzyme laccase, extraction with ether, and treatment with alkali. Yeast growth in lignocellulosic hydrolysates was inhibited below a certain fermentation pH, most likely due to high concentrations of undissociated weak acids. The effect of individual compounds were studied in model fermentations. Furfural is reduced to furfuryl alcohol by yeast dehydrogenases, thereby affecting the intracellular redox balance. As a result, acetaldehyde accumulated during furfural reduction, which most likely contributed to inhibition of growth. Acetic acid (10 g 1{sup -1}) and furfural (3 g 1{sup -1}) interacted antagonistically causing decreased specific growth rate, whereas no significant individual or interaction effects were detected by the lignin-derived compound 4-hydroxybenzoic acid (2 g 1{sup -1}). By maintaining a high cell mass density in the fermentor, the process was less sensitive to inhibitors affecting growth and to fluctuations in fermentation pH, and in addition the depletion rate of bioconvertible inhibitors was increased. A theoretical ethanol yield and high productivity was obtained in continuous fermentation of spruce hydrolysate when the cell mass concentration was maintained at a high level by applying cell recirculation 164 refs, 16 figs, 5 tabs

  18. The Brewing Process: Optimizing the Fermentation

    OpenAIRE

    Teodora Coldea; Elena Mudura; Călin Şibotean; Emil Comşa

    2014-01-01

    Beer is a carbonated alcoholic beverage obtained by alcoholic fermentation of malt wort boiled with hops. Brown beer obtained at Beer Pilot Station of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca was the result of a recipe based on blond, caramel and black malt in different proportions, water, hops and yeast. This study aimed to monitorize the evolution of wort in primary and secondary alcoholic fermentation in order to optimize the process. Two wort batches were as...

  19. Hydrogen fermentation properties of undiluted cow dung.

    Science.gov (United States)

    Yokoyama, Hiroshi; Waki, Miyoko; Ogino, Akifumi; Ohmori, Hideyuki; Tanaka, Yasuo

    2007-07-01

    Anaerobic treatment of undiluted cow dung (15% total solids), so-called dry fermentation, produced hydrogen (743 ml-H(2)/kg-cow dung) at an optimum temperature of 60 degrees C, with butyrate and acetate formation. The hydrogen production was inhibited by the addition of NH(4)(+) in a dose-dependent manner. A bacterium with similarity to Clostridium cellulosi was detected in the fermented dung by a 16S rDNA analysis.

  20. FERMENTED MILK AS A FUNCTIONAL FOOD

    OpenAIRE

    Irena Rogelj

    2000-01-01

    Certain foods have been associated with health benefits for many years; fermented milks and yoghurt are typical examples. The health properties of these dairy products were a part of folklore until the concept of probiotics emerged, and the study of fermented milks and yoghurt containing probiotic bacteria has become more systematic. Functional foods have thus developed as a food, or food ingredient, with positive effects on host health and/or well-being beyond their nutritional value, and fe...

  1. Directing product formation by mixed culture fermentation

    OpenAIRE

    Temudo, M.F.

    2008-01-01

    Our society is dealing with the shortage of fossil fuels and chemical feedstocks and, on the other hand, with the increase of wastes generated by municipalities, agriculture and industries. Biobased industry, the conversion of renewable resources or wastes to chemicals and fuels, by microbial fermentations or enzymes has been receiving increasingly attention. The aim is to develop new technologies, increase efficiencies and reduce the costs in fermentation, bioconversion, and in downstream pr...

  2. Biochemical analysis of extracting fermented coconut oil

    OpenAIRE

    YATI SUDARYATI SOEKA; JOKO SULISTYO; ELIDAR NAIOLA

    2008-01-01

    Vegetable oil can be produced from a perennial plant such as coconut (Cocos nucifera L.). There are few techniques for coconut oil extraction, such as physical, chemical, and fermentative processes. The fermentation process uses microbial inoculum as starter. Ground coconut meat was soaked in warm water, than squeezed several times to get coconut milk. After being allowed to stand for 4-5 hours, it separated into two layers, cream and skim. Starter was prepared from a mixture of milk and coco...

  3. Coffee fermentation and flavor--An intricate and delicate relationship.

    Science.gov (United States)

    Lee, Liang Wei; Cheong, Mun Wai; Curran, Philip; Yu, Bin; Liu, Shao Quan

    2015-10-15

    The relationship between coffee fermentation and coffee aroma is intricate and delicate at which the coffee aroma profile is easily impacted by the fermentation process during coffee processing. However, as the fermentation process in coffee processing is conducted mainly for mucilage removal, its impacts on coffee aroma profile are usually neglected. Therefore, this review serves to summarize the available literature on the impacts of fermentation in coffee processing on coffee aroma as well as other unconventional avenues where fermentation is employed for coffee aroma modulation. Studies have noted that proper control over the fermentation process imparts desirable attributes and prevents undesirable fermentation which generates off-flavors. Other unconventional avenues in which fermentation is employed for aroma modulation include digestive bioprocessing and the fermentation of coffee extracts and green coffee beans. The latter is an area that should be explored further with appropriate microorganisms given its potential for coffee aroma modulation.

  4. Co-fermentation of organic residues; Mitbehandlung von organischen Reststoffen in Faulanlagen, Co-Fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Rosenwinkel, K.H.; Wendler, D.; Urban, I. [Inst. fuer Siedlungswasserwirtschaft und Abfalltechnik, Univ. Hannover (Germany)

    2004-07-01

    The report outlines the social and process-related fundamentals of power generation from communal and industrial organic residues. On the other hand, the main results of a nation-wide enquiry on co-fermentation of organic residues in fermenters of communal sewage systems in Germany are presented. (orig.)

  5. Simultaneous Saccharification and Fermentation of Overnight Soaked Sweet Potato for Ethyl Alcohol Fermentation

    Directory of Open Access Journals (Sweden)

    B.K. Mishra

    2012-04-01

    Full Text Available The aim of the study is to develop an efficient method of production of ethyl alcohol by fermentation of sweet potato powder. The method emphasized on enhancement of "-amylase accessibility by overnight soaking of sweet potato powder and decreasing unwanted bacterial fermentation by utilizing simultaneous saccharification and fermentation. The crystalline structure of starch limits the accessibility of "-amylase to starch during enzymatic hydrolysis and thus reduces hydrolysis rate. This might be the reason for longer hydrolysis time. Effect of overnight soaking in water on eight variety of sweet potato was investigated followed by Simultaneous Saccharification and Fermentation (SSF. The result reflected the advantage of overnight soaking on "-amylase accessibility to starch, which favor higher hydrolysis rate. Implementing SSF, the fermentation process become efficient due to less free sugar at an instant and maximum efficiency of 96.7% was achieved in a 64.65% starch containing substrate.

  6. The Design of Automatic Stirring Ripe Tea Fermenter for Puer Tea

    OpenAIRE

    Wu Xiaoqiang

    2015-01-01

    Traditional ripe tea fermentation is directly stacking puer tea material on the ground of fermentation workshop relying on natural environment to ferment. The way of fermentation, which has poor degree of sanitation, makes fermentation process influenced by environmental change and difficult to ensure product quality and stability. To solve this problem, we design a ripe tea fermenter for puer tea. There is a certain distance between fermenter and the ground and the spindle of fermenter is de...

  7. Yeast Biodiversity from DOQ Priorat Uninoculated Fermentations.

    Science.gov (United States)

    Padilla, Beatriz; García-Fernández, David; González, Beatriz; Izidoro, Iara; Esteve-Zarzoso, Braulio; Beltran, Gemma; Mas, Albert

    2016-01-01

    Climate, soil, and grape varieties are the primary characteristics of terroir and lead to the definition of various appellations of origin. However, the microbiota associated with grapes are also affected by these conditions and can leave a footprint in a wine that will be part of the characteristics of terroir. Thus, a description of the yeast microbiota within a vineyard is of interest not only to provide a better understanding of the winemaking process, but also to understand the source of microorganisms that maintain a microbial footprint in wine from the examined vineyard. In this study, two typical grape varieties, Grenache and Carignan, have been sampled from four different vineyards in the DOQ Priorat winegrowing region. Afterward, eight spontaneous alcoholic fermentations containing only grapes from one sampling point and of one variety were conducted at laboratory scale. The fermentation kinetics and yeast population dynamics within each fermentation experiment were evaluated. Yeast identification was performed by RFLP-PCR of the 5.8S-ITS region and by sequencing D1/D2 of the 26S rRNA gene of the isolates. The fermentation kinetics did not indicate clear differences between the two varieties of grapes or among vineyards. Approximately 1,400 isolates were identified, exhibiting high species richness in some fermentations. Of all the isolates studied, approximately 60% belong to the genus Hanseniaspora, 16% to Saccharomyces, and 11% to Candida. Other minor genera, such as Hansenula, Issatchenkia, Kluyveromyces, Saccharomycodes, and Zygosaccharomyces, were also found. The distribution of the identified yeast throughout the fermentation process was studied, and Saccharomyces cerevisiae was found to be present mainly at the end of the fermentation process, while Aureobasidium pullulans was isolated primarily during the first days of fermentation in three of the eight spontaneous fermentations. This work highlights the complexity and diversity of the vineyard

  8. Yeast Biodiversity from DOQ Priorat Uninoculated Fermentations

    Science.gov (United States)

    Padilla, Beatriz; García-Fernández, David; González, Beatriz; Izidoro, Iara; Esteve-Zarzoso, Braulio; Beltran, Gemma; Mas, Albert

    2016-01-01

    Climate, soil, and grape varieties are the primary characteristics of terroir and lead to the definition of various appellations of origin. However, the microbiota associated with grapes are also affected by these conditions and can leave a footprint in a wine that will be part of the characteristics of terroir. Thus, a description of the yeast microbiota within a vineyard is of interest not only to provide a better understanding of the winemaking process, but also to understand the source of microorganisms that maintain a microbial footprint in wine from the examined vineyard. In this study, two typical grape varieties, Grenache and Carignan, have been sampled from four different vineyards in the DOQ Priorat winegrowing region. Afterward, eight spontaneous alcoholic fermentations containing only grapes from one sampling point and of one variety were conducted at laboratory scale. The fermentation kinetics and yeast population dynamics within each fermentation experiment were evaluated. Yeast identification was performed by RFLP-PCR of the 5.8S-ITS region and by sequencing D1/D2 of the 26S rRNA gene of the isolates. The fermentation kinetics did not indicate clear differences between the two varieties of grapes or among vineyards. Approximately 1,400 isolates were identified, exhibiting high species richness in some fermentations. Of all the isolates studied, approximately 60% belong to the genus Hanseniaspora, 16% to Saccharomyces, and 11% to Candida. Other minor genera, such as Hansenula, Issatchenkia, Kluyveromyces, Saccharomycodes, and Zygosaccharomyces, were also found. The distribution of the identified yeast throughout the fermentation process was studied, and Saccharomyces cerevisiae was found to be present mainly at the end of the fermentation process, while Aureobasidium pullulans was isolated primarily during the first days of fermentation in three of the eight spontaneous fermentations. This work highlights the complexity and diversity of the vineyard

  9. Yeast Biodiversity from DOQ Priorat Uninoculated Fermentations.

    Science.gov (United States)

    Padilla, Beatriz; García-Fernández, David; González, Beatriz; Izidoro, Iara; Esteve-Zarzoso, Braulio; Beltran, Gemma; Mas, Albert

    2016-01-01

    Climate, soil, and grape varieties are the primary characteristics of terroir and lead to the definition of various appellations of origin. However, the microbiota associated with grapes are also affected by these conditions and can leave a footprint in a wine that will be part of the characteristics of terroir. Thus, a description of the yeast microbiota within a vineyard is of interest not only to provide a better understanding of the winemaking process, but also to understand the source of microorganisms that maintain a microbial footprint in wine from the examined vineyard. In this study, two typical grape varieties, Grenache and Carignan, have been sampled from four different vineyards in the DOQ Priorat winegrowing region. Afterward, eight spontaneous alcoholic fermentations containing only grapes from one sampling point and of one variety were conducted at laboratory scale. The fermentation kinetics and yeast population dynamics within each fermentation experiment were evaluated. Yeast identification was performed by RFLP-PCR of the 5.8S-ITS region and by sequencing D1/D2 of the 26S rRNA gene of the isolates. The fermentation kinetics did not indicate clear differences between the two varieties of grapes or among vineyards. Approximately 1,400 isolates were identified, exhibiting high species richness in some fermentations. Of all the isolates studied, approximately 60% belong to the genus Hanseniaspora, 16% to Saccharomyces, and 11% to Candida. Other minor genera, such as Hansenula, Issatchenkia, Kluyveromyces, Saccharomycodes, and Zygosaccharomyces, were also found. The distribution of the identified yeast throughout the fermentation process was studied, and Saccharomyces cerevisiae was found to be present mainly at the end of the fermentation process, while Aureobasidium pullulans was isolated primarily during the first days of fermentation in three of the eight spontaneous fermentations. This work highlights the complexity and diversity of the vineyard

  10. CITRIC ACID PRODUCTION USING FERMENTATION TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    ANKIT KUMAR

    2007-01-01

    Full Text Available Citric acid, C3H4OH(COOH3, (Scheele and Wehmer 1897 can be generally manufactured by chemical synthesis which is not much preferred now-a-days because of high costs involved in it and also by fermentation of sugar containing sources in the presence of fungus Aspergillus niger. Citric acid is used in confections and soft drinks ( as a flavouring agent, in metal-cleaning compositions, and in improving the stability of foods and other organic substances by suppressing the deleterious action of dissolved metal salts. Fermentation results in the breakdown of complex organic substances into simpler ones through the action of catalysis. This project involves the production of citric acid from fungal strain of Aspergillus niger ATCC 9142, using various sources like cane molasses, beet molasses, sweet potato and grape sugar by employing submerged and surface fermentation. The fermentation process has been carried out at ph 4.5 and temperature 28 0C. The recovery of citric acid from fermented broth is generally performed through three procedures-precipitation, extraction and adsorption(mainly using ion-exchange resins. The main aim of the project is to achieve a cost reduction in citric acid production by using less expensive substrates.

  11. Swine manure fermentation for hydrogen production.

    Science.gov (United States)

    Zhu, Jun; Li, Yecong; Wu, Xiao; Miller, Curtis; Chen, Paul; Ruan, Roger

    2009-11-01

    Biohydrogen fermentation using liquid swine manure as substrate supplemented with glucose was investigated in this project. Experiments were conducted using a semi-continuously-fed fermenter (8L in total volume and 4 L in working volume) with varying pHs from 4.7 through 5.9 under controlled temperature (35+/-1 degrees C). The hydraulic retention time (HRT) tested include 16, 20, and 24h; however, in two pH conditions (5.0 and 5.3), an additional HRT of 12h was also tried. The experimental design combining HRT and pH provided insight on the fermenter performance in terms of hydrogen generation. The results indicated that both HRT and pH had profound influences on fermentative hydrogen productivity. A rising HRT would lead to greater variation in hydrogen concentration in the offgas and the best HRT was found to be 16 h for the fermenter in this study. The best pH value in correspondence to the highest hydrogen generation was revealed to be 5.0 among all the pHs studied. There was no obvious inhibition on hydrogen production by methanogenesis when methane content in the offgas was lower than 2%. Otherwise, an inverse linear relationship between hydrogen and methane content was observed with a correlation coefficient of 0.9699. Therefore, to increase hydrogen content in the offgas, methane production has to be limited to below 2%. PMID:19157863

  12. Regulation of alcohol fermentation by Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D.P.

    1989-01-01

    The purpose of this project is to elucidate the way in which the fermentative synthesis of ethanol is regulated in the facultative anaerobe Escherichia coli. We are also investigating the control of other genes required for fermentation and anaerobic growth. We have isolated both structural and regulatory mutations affecting the expression of alcohol dehydrogenase, the enzyme responsible for the final step in alcohol synthesis. Some of these regulatory mutations also affect other anaerobically induced genes. The adh gene has been cloned and sequenced. The ADH protein is one of the largest highly expressed proteins in E. coli and requires approximately 2700bp of DNA for its cloning sequence. We have also isolated mutations affecting the fermentative lactate dehydrogenase. In consequence it is now possible to construct E. coli strains defective in the production of any one or more of their normal fermentation products (i.e. formate, acetate, lactate, ethanol and succinate). The factors affecting the ratio of fermentation products are being investigated by in vivo NMR spectroscopy.

  13. Xylose fermentation to ethanol. A review

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, J D

    1993-01-01

    The past several years have seen tremendous progress in the understanding of xylose metabolism and in the identification, characterization, and development of strains with improved xylose fermentation characteristics. A survey of the numerous microorganisms capable of directly fermenting xylose to ethanol indicates that wild-type yeast and recombinant bacteria offer the best overall performance in terms of high yield, final ethanol concentration, and volumetric productivity. The best performing bacteria, yeast, and fungi can achieve yields greater than 0.4 g/g and final ethanol concentrations approaching 5%. Productivities remain low for most yeast and particularly for fungi, but volumetric productivities exceeding 1.0 g/L-h have been reported for xylose-fermenting bacteria. In terms of wild-type microorganisms, strains of the yeast Pichia stipitis show the most promise in the short term for direct high-yield fermentation of xylose without byproduct formation. Of the recombinant xylose-fermenting microorganisms developed, recombinant E. coli ATTC 11303 (pLOI297) exhibits the most favorable performance characteristics reported to date.

  14. Preparation of Soy Peptides by Liquid Fermentation

    Institute of Scientific and Technical Information of China (English)

    LiLi; YangXiaoqun; ZhaoMouming; LiangShizhong

    2002-01-01

    Many kinds of microorganism can produce a mount of protease which subsequently hydrolysis the protein of the medium into peptides when they grow in protein containing liquid medium.In the present investigation,the conditions of preparing soybean peptides by liquid fermentation were studied,following results were obtained:(1)SPI is a nice nitrogen source and meanwhile an inducible factor of protease production;its concentration can be as high as 3%-4%.(2)Sucrose is the best carbon source;its concentration is 1%-4%.(3)Under the conditions of 28℃,initial pH6.0,inoculum size 4%,cell age 36hr and fermentation time 24hr-30hr,we can obtain soybean peptides or fermentation liquor with good flavor,its DH reaches 25%-30% and the yield rate can be as high as 75%.(4)Mass spectrograph indicate the MW of the fermentation liquid or the soybean peptides mainly distribute at about 4000Dal,these imply a promising prospect of industrial application of submerged fermentation in producing soybean peptides.

  15. Enamel microhardness and fluoride uptake underneath fermenting and non-fermenting artificial plaque.

    Science.gov (United States)

    Turtola, L O

    1977-09-01

    Washed cells of Streptococcus sanguis were used to form artificial plaque on the surface of bovine enamel and incubated underneath buffer solutions, initial pH 6, for 36 h at 37 degrees C. The decrease in the microhardness of the enamel surface under fermenting "plaque" could be prevented with fluoride. Enamel under a fermenting "plaque" took up significantly more (P less than 0.0u) fluoride than enamel under a non-fermenting "plaque" (initial F- in buffer: 10 parts/10(6)). The artificial plaque did not accumulate fluoride. Within fermenting "plaques/, the pH decreased significantly more without flouride (P less than 0.01) than with fluoride. Fluoride combined with sucrose more than negated the softening of the enamel caused by sucrose fermentation, i.e. it increased the hardness above the original values. The diffusion of fluoride through the fermenting artificial plaque was more rapid than through a non-fermenting plaque. These findings suggest that caries-conducive circumstances may promote fluoride uptake by enamel compared with non-caries-conducive circumstances.

  16. Glycerol production by fermenting yeast cells is essential for optimal bread dough fermentation.

    Science.gov (United States)

    Aslankoohi, Elham; Rezaei, Mohammad Naser; Vervoort, Yannick; Courtin, Christophe M; Verstrepen, Kevin J

    2015-01-01

    Glycerol is the main compatible solute in yeast Saccharomyces cerevisiae. When faced with osmotic stress, for example during semi-solid state bread dough fermentation, yeast cells produce and accumulate glycerol in order to prevent dehydration by balancing the intracellular osmolarity with that of the environment. However, increased glycerol production also results in decreased CO2 production, which may reduce dough leavening. We investigated the effect of yeast glycerol production level on bread dough fermentation capacity of a commercial bakery strain and a laboratory strain. We find that Δgpd1 mutants that show decreased glycerol production show impaired dough fermentation. In contrast, overexpression of GPD1 in the laboratory strain results in increased fermentation rates in high-sugar dough and improved gas retention in the fermenting bread dough. Together, our results reveal the crucial role of glycerol production level by fermenting yeast cells in dough fermentation efficiency as well as gas retention in dough, thereby opening up new routes for the selection of improved commercial bakery yeasts.

  17. Influence of aeration in the fermentative activity of Kloeckera apiculata during fermentation of apple juice

    International Nuclear Information System (INIS)

    The influence of aeration on the fermentative activity of Kloeckera apiculata RIVE 9-2-1 was studied in order to evaluate the production of metabolites of the fermentation. To achieve this, the strain was cultured in Erlenmeyer flasks containing sterilized and aroma removed apple juice, and the chemical compounds produced during fermentation in shaken (200 min-1) and static (without agitation) cultivation were determined. The results showed that the agitation of the culture medium increases production of higher alcohols (till 591.0 mg/L) compared to static cultivation, whereas on the contrary, the production of acetic acid, ethyl acetate and glycerol (260.0 ± 11.0 mg/L, 196.0 ± 10.0 mg/L y 2.6±0.2 g/L) were higher compared to shaken cultivation (222.0 ± 8.0 mg/L, 96.0 ± 4.5 mg/L and 1.8 ± 0.2 g/L) respectively. Batch cultivations carried out in bioreactor with air flux of 25 l/h reported a growth rate μ of 0.17 h-1, production of ethanol (12.5 ± 2.0 g/L) and other compounds typically produced during alcoholic fermentation. The concentration of dissolved oxygen in the fermentation medium affects its metabolism thus; insufficient amounts of oxygen would provoke a respirofermentative metabolism. The best results in terms of organoleptic quality of the fermented beverage regarding to aroma, taste and flavor was obtained when fermented in static cultivation. The control of aeration during fermentation can be used to control the synthesis of chemical compounds of sensory impact in the production of fermented beverages.

  18. Fermentable sugars from biopolymers of bagasse

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, K.; Das, K.; Sharma, D.K.

    1987-11-01

    Ethanol can replace oil as a fuel and its use would help in the conservation of the meagre oil reserves in India. The article indicates some convenient and cost-effective processes for the production of ethanol from biopolymers available in bagasse, an agricultural residue. A two-stage acid hydrolysis process produced a maximum of fermentable sugars at 35%. Calcium chloride used as a promoter enhanced production by 3.5%. Other promoters are under investigation. Agitation had a significant effect on production, complete hydrolysis being possible between 10-45 minutes depending on temperature. The fermentable sugars obtained, xylose and glucose, can then be fermented to ethanol in an integrated three-stage process. 11 refs., 3 figs., 3 tabs.

  19. Yeast interactions in inoculated wine fermentation

    Directory of Open Access Journals (Sweden)

    Maurizio eCiani

    2016-04-01

    Full Text Available The use of selected starter culture is widely diffused in winemaking. In pure fermentation, the ability of inoculated Saccharomyces cerevisiae to suppress the wild microflora is one of the most important feature determining the starter ability to dominate the process. Since the wine is the result of the interaction of several yeast species and strains, many studies are available on the effect of mixed cultures on the final wine quality. In mixed fermentation the interactions between the different yeasts composing the starter culture can led the stability of the final product and the analytical and aromatic profile. In the present review, we will discuss the recent developments regarding yeast interactions in pure and in mixed fermentation, focusing on the influence of interactions on growth and dominance in the process.

  20. Yeast Interactions in Inoculated Wine Fermentation

    Science.gov (United States)

    Ciani, Maurizio; Capece, Angela; Comitini, Francesca; Canonico, Laura; Siesto, Gabriella; Romano, Patrizia

    2016-01-01

    The use of selected starter culture is widely diffused in winemaking. In pure fermentation, the ability of inoculated Saccharomyces cerevisiae to suppress the wild microflora is one of the most important feature determining the starter ability to dominate the process. Since the wine is the result of the interaction of several yeast species and strains, many studies are available on the effect of mixed cultures on the final wine quality. In mixed fermentation the interactions between the different yeasts composing the starter culture can led the stability of the final product and the analytical and aromatic profile. In the present review, we will discuss the recent developments regarding yeast interactions in pure and in mixed fermentation, focusing on the influence of interactions on growth and dominance in the process. PMID:27148235

  1. Challenges in industrial fermentation technology research

    DEFF Research Database (Denmark)

    Formenti, Luca Riccardo; Nørregaard, Anders; Bolic, Andrijana;

    2014-01-01

    Industrial fermentation processes are increasingly popular, and are considered an important technological asset for reducing our dependence on chemicals and products produced from fossil fuels. However, despite their increasing popularity, fermentation processes have not yet reached the same...... engineering challenges: scaling up and scaling down fermentation processes, the influence of morphology on broth rheology and mass transfer, and establishing novel sensors to measure and control insightful process parameters. The greatest emphasis is on the challenges posed by filamentous fungi, because...... of their wide applications as cell factories and therefore their relevance in a White Biotechnology context. Computational fluid dynamics (CFD) is introduced as a promising tool that can be used to support the scaling up and scaling down of bioreactors, and for studying mixing and the potential occurrence...

  2. A comprehensive and quantitative review of dark fermentative biohydrogen production

    OpenAIRE

    Rittmann Simon; Herwig Christoph

    2012-01-01

    Abstract Biohydrogen production (BHP) can be achieved by direct or indirect biophotolysis, photo-fermentation and dark fermentation, whereof only the latter does not require the input of light energy. Our motivation to compile this review was to quantify and comprehensively report strains and process performance of dark fermentative BHP. This review summarizes the work done on pure and defined co-culture dark fermentative BHP since the year 1901. Qualitative growth characteristics and quantit...

  3. Fermentation and Anaerobic Respiration by Rhodospirillum rubrum and Rhodopseudomonas capsulata

    OpenAIRE

    Schultz, J E; Weaver, P. F.

    1982-01-01

    Rhodospirillum rubrum and Rhodopseudomonas capsulata were able to grow anaerobically in the dark either by a strict mixed-acid fermentation of sugars or, in the presence of an appropriate electron acceptor, by an energy-linked anaerobic respiration. Both species fermented fructose without the addition of accessory oxidants, but required the initial presence of bicarbonate before fermentative growth could begin. Major products of R. rubrum fermentation were succinate, acetate, propionate, form...

  4. Effects of fermented soya bean on digestion, absorption and diarrhoea

    OpenAIRE

    Kiers, J.L.

    2001-01-01

    For many centuries Asian people have consumed soya beans in various forms of traditional fermented soya bean foods. Major desirable aspects of fermented soya bean foods are their attractive flavour and texture, certain nutritional properties, and possible health promoting effects. This study describes effects of fermented soya beans on gastrointestinal physiology and addresses digestion, absorption and diarrhoea.Using an in vitro digestion model it appeared that fermentation increased solubil...

  5. Effects of Salt on Wheat Flour Dough Fermentation

    OpenAIRE

    Toshiyuki Toyosaki; Yasuhide Sakane

    2013-01-01

    Most food chemistry characteristics in the dough fermentation of salt are not solved. Effects of salt on the acceleration process of wheat flour dough fermentation were studied, respectively. The mechanism of dough expansion influenced by salt and yeast was also investigated. The dough expansion rate with no salt reached a maximum of 18% in the 50 min dough fermentation time. In contrast, dough with 2.0% salt reached an expansion rate of 96% in 30 min of fermentation. Furthermore, the maximum...

  6. Scaling Relationships for Spherical Polymer Brushes Revisited.

    Science.gov (United States)

    Chen, Guang; Li, Hao; Das, Siddhartha

    2016-06-16

    In this short paper, we revisit the scaling relationships for spherical polymer brushes (SPBs), i.e., polymer brushes grafted to rigid, spherical particles. Considering that the brushes can be described to be encased in a series of hypothetical spherical blobs, we identify significant physical discrepancies in the model of Daoud and Cotton (Journal of Physics, 1982), which is considered to be the state of the art in scaling modeling of SPBs. We establish that the "brush" configuration of the polymer molecules forming the SPBs is possible only if the swelling ratio (which is the ratio of the end-to-end length of the blob-encased polymer segment to the corresponding coil-like polymer segment) is always less than unity-a notion that has been erroneously overlooked in the model of Daoud and Cotton. We also provide new scaling arguments that (a) establish this swelling (or more appropriately shrinking) ratio as a constant (less than unity) for the case of "good" solvent, (b) recover the scaling predictions for blob dimension and monomer number and monomer concentration distributions within the blob, and

  7. Charge symmetry breaking in $\\Lambda$ hypernuclei revisited

    CERN Document Server

    Gal, Avraham

    2015-01-01

    The large charge symmetry breaking (CSB) implied by the $\\Lambda$ binding energy difference $\\Delta B^{4}_{\\Lambda}(0^+_{\\rm g.s.})\\equiv B_{\\Lambda}(_{\\Lambda}^4$He)$-$$B_{\\Lambda}(_{\\Lambda}^4$H) = 0.35$\\pm$0.06 MeV of the $A=4$ mirror hypernuclei ground states, determined from emulsion studies, has defied theoretical attempts to reproduce it in terms of CSB in hyperon masses and in hyperon-nucleon interactions, including one pion exchange arising from $\\Lambda-\\Sigma^0$ mixing. Using a schematic strong-interaction $\\Lambda N\\leftrightarrow\\Sigma N$ coupling model developed by Akaishi and collaborators for $s$-shell $\\Lambda$ hypernuclei, we revisit the evaluation of CSB in the $A=4$ $\\Lambda$ hypernuclei and extend it to $p$-shell mirror $\\Lambda$ hypernuclei. The model yields values of $\\Delta B^{4}_{\\Lambda} (0^+_{\\rm g.s.})\\sim 0.25$ MeV. Smaller size and mostly negative $p$-shell binding energy differences are calculated for the $A=7-10$ mirror hypernuclei, in rough agreement with the few available dat...

  8. Targeting Cancer Metabolism - Revisiting the Warburg Effects.

    Science.gov (United States)

    Tran, Quangdon; Lee, Hyunji; Park, Jisoo; Kim, Seon-Hwan; Park, Jongsun

    2016-07-01

    After more than half of century since the Warburg effect was described, this atypical metabolism has been standing true for almost every type of cancer, exhibiting higher glycolysis and lactate metabolism and defective mitochondrial ATP production. This phenomenon had attracted many scientists to the problem of elucidating the mechanism of, and reason for, this effect. Several models based on oncogenic studies have been proposed, such as the accumulation of mitochondrial gene mutations, the switch from oxidative phosphorylation respiration to glycolysis, the enhancement of lactate metabolism, and the alteration of glycolytic genes. Whether the Warburg phenomenon is the consequence of genetic dysregulation in cancer or the cause of cancer remains unknown. Moreover, the exact reasons and physiological values of this peculiar metabolism in cancer remain unclear. Although there are some pharmacological compounds, such as 2-deoxy-D-glucose, dichloroacetic acid, and 3-bromopyruvate, therapeutic strategies, including diet, have been developed based on targeting the Warburg effect. In this review, we will revisit the Warburg effect to determine how much scientists currently understand about this phenomenon and how we can treat the cancer based on targeting metabolism. PMID:27437085

  9. The drive revisited: Mastery and satisfaction.

    Science.gov (United States)

    Denis, Paul

    2016-06-01

    Starting from the theory of the libido and the notions of the experience of satisfaction and the drive for mastery introduced by Freud, the author revisits the notion of the drive by proposing the following model: the drive takes shape in the combination of two currents of libidinal cathexis, one which takes the paths of the 'apparatus for obtaining mastery' (the sense-organs, motricity, etc.) and strives to appropriate the object, and the other which cathects the erotogenic zones and the experience of satisfaction that is experienced through stimulation in contact with the object. The result of this combination of cathexes constitutes a 'representation', the subsequent evocation of which makes it possible to tolerate for a certain period of time the absence of a satisfying object. On the basis of this conception, the author distinguishes the representations proper, vehicles of satisfaction, from imagos and traumatic images which give rise to excitation that does not link up with the paths taken by the drives. This model makes it possible to conciliate the points of view of the advocates of 'object-seeking' and of those who give precedence to the search for pleasure, and, further, to renew our understanding of object-relations, which can then be approached from the angle of their relations to infantile sexuality. Destructiveness is considered in terms of "mastery madness" and not in terms of the late Freudian hypothesis of the death drive.

  10. Revisiting the argument from fetal potential

    Directory of Open Access Journals (Sweden)

    Manninen Bertha

    2007-05-01

    Full Text Available Abstract One of the most famous, and most derided, arguments against the morality of abortion is the argument from potential, which maintains that the fetus' potential to become a person and enjoy the valuable life common to persons, entails that its destruction is prima facie morally impermissible. In this paper, I will revisit and offer a defense of the argument from potential. First, I will criticize the classical arguments proffered against the importance of fetal potential, specifically the arguments put forth by philosophers Peter Singer and David Boonin, by carefully unpacking the claims made in these arguments and illustrating why they are flawed. Secondly, I will maintain that fetal potential is morally relevant when it comes to the morality of abortion, but that it must be accorded a proper place in the argument. This proper place, however, cannot be found until we first answer a very important and complex question: we must first address the issue of personal identity, and when the fetus becomes the type of being who is relevantly identical to a future person. I will illustrate why the question of fetal potential can only be meaningfully addressed after we have first answered the question of personal identity and how it relates to the human fetus.

  11. Revisiting the relaxation dynamics of isolated pyrrole

    Energy Technology Data Exchange (ETDEWEB)

    Montero, Raúl; Ovejas, Virginia; Fernández-Fernández, Marta; Longarte, Asier, E-mail: asier.longarte@ehu.es [Departamento de Química Física, Universidad del País Vasco (UPV/EHU), Apart. 644, 48080 Bilbao (Spain); Peralta Conde, Álvaro [Centro de Láseres Pulsados (CLPU), Edificio M3, Parque Científico, 37185 Villamayor (Spain)

    2014-07-07

    Herein, the interpretation of the femtosecond-scale temporal evolution of the pyrrole ion signal, after excitation in the 267–217 nm interval, recently published by our group [R. Montero, A. Peralta Conde, V. Ovejas, M. Fernández-Fernández, F. Castaño, J. R. Vázquez de Aldana, and A. Longarte, J. Chem. Phys.137, 064317 (2012)] is re-visited. The observation of a shift in the pyrrole{sup +} transient respect to zero delay reference, initially attributed to ultrafast dynamics on the πσ{sup *} type state (3s a{sub 1} ← π 1a{sub 2}), is demonstrated to be caused by the existence of pump + probe populated states, along the ionization process. The influence of these resonances in pump-prone ionization experiments, when multi-photon probes are used, and the significance of a proper zero-time reference, is discussed. The possibility of preparing the πσ{sup *} state by direct excitation is investigated by collecting 1 + 1 photoelectron spectra, at excitation wavelengths ranging from 255 to 219 nm. No conclusive evidences of ionization through this state are found.

  12. Targeting Cancer Metabolism - Revisiting the Warburg Effects

    Science.gov (United States)

    Tran, Quangdon; Lee, Hyunji; Park, Jisoo; Kim, Seon-Hwan; Park, Jongsun

    2016-01-01

    After more than half of century since the Warburg effect was described, this atypical metabolism has been standing true for almost every type of cancer, exhibiting higher glycolysis and lactate metabolism and defective mitochondrial ATP production. This phenomenon had attracted many scientists to the problem of elucidating the mechanism of, and reason for, this effect. Several models based on oncogenic studies have been proposed, such as the accumulation of mitochondrial gene mutations, the switch from oxidative phosphorylation respiration to glycolysis, the enhancement of lactate metabolism, and the alteration of glycolytic genes. Whether the Warburg phenomenon is the consequence of genetic dysregulation in cancer or the cause of cancer remains unknown. Moreover, the exact reasons and physiological values of this peculiar metabolism in cancer remain unclear. Although there are some pharmacological compounds, such as 2-deoxy-D-glucose, dichloroacetic acid, and 3-bromopyruvate, therapeutic strategies, including diet, have been developed based on targeting the Warburg effect. In this review, we will revisit the Warburg effect to determine how much scientists currently understand about this phenomenon and how we can treat the cancer based on targeting metabolism. PMID:27437085

  13. [What mirror neurons have revealed: revisited].

    Science.gov (United States)

    Murata, Akira; Maeda, Kazutaka

    2014-06-01

    The first paper on mirror neurons was published in 1992. In the span of over two decades since then, much knowledge about the relationship between social cognitive function and the motor control system has been accumulated. Direct matching of visual actions and their corresponding motor representations is the most important functional property of mirror neuron. Many studies have emphasized intrinsic simulation as a core concept for mirror neurons. Mirror neurons are thought to play a role in social cognitive function. However, the function of mirror neurons in the macaque remains unclear, because such cognitive functions are limited or lacking in macaque monkeys. It is therefore important to discuss these neurons in the context of motor function. Rizzolatti and colleagues have stressed that the most important function of mirror neurons in macaques is recognition of actions performed by other individuals. I suggest that mirror neurons in the Macaque inferior pariental lobule might be correlated with body schema. In the parieto-premotor network, matching of corollary discharge and actual sensory feedback is an essential neuronal operation. Recently, neurons showing mirror properties were found in some cortical areas outside the mirror neuron system. The current work would revisit the outcomes of mirror neuron studies to discuss the function of mirror neurons in the monkey.

  14. Revisiting Twomey's approximation for peak supersaturation

    Directory of Open Access Journals (Sweden)

    B. J. Shipway

    2014-10-01

    Full Text Available Twomey's seminal 1959 paper provided lower and upper bound approximations to the estimation of peak supersaturation within an updraft and thus provides the first closed expression for the number of nucleated cloud droplets. The form of this approximation is simple, but provides a surprisingly good estimate and has subsequently been employed in more sophisticated treatments of nucleation parametrization. In the current paper, we revisit the lower bound approximation of Twomey and make a small adjustment which can be used to obtain a more accurate calculation of peak supersaturation under all potential aerosol loadings and thermodynamic conditions. In order to make full use of this improved approximation, the underlying integro-differential equation for supersaturation evolution and the condition for calculating peak supersaturation are examined. A simple rearrangement of the algebra allows for an expression to be written down which can then be solved with a single lookup table with only one independent variable for an underlying lognormal aerosol population. Multimode aerosol with only N different dispersion characteristics require only N of these one-dimensional lookup tables. No additional information is required in the lookup table to deal with additional chemical, physical or thermodynamic properties. The resulting implementation provides a relatively simple, yet computationally cheap and very accurate physically-based parametrization of droplet nucleation for use in climate and NWP models.

  15. The Super-GUT CMSSM Revisited

    CERN Document Server

    Ellis, John; Mustafayev, Azar; Nagata, Natsumi; Olive, Keith A

    2016-01-01

    We revisit minimal supersymmetric SU(5) grand unification (GUT) models in which the soft supersymmetry-breaking parameters of the minimal supersymmetric Standard Model (MSSM) are universal at some input scale, $M_{in}$, above the supersymmetric gauge coupling unification scale, $M_{GUT}$. As in the constrained MSSM (CMSSM), we assume that the scalar masses and gaugino masses have common values, $m_0$ and $m_{1/2}$ respectively, at $M_{in}$, as do the trilinear soft supersymmetry-breaking parameters $A_0$. Going beyond previous studies of such a super-GUT CMSSM scenario, we explore the constraints imposed by the lower limit on the proton lifetime and the LHC measurement of the Higgs mass, $m_h$. We find regions of $m_0$, $m_{1/2}$, $A_0$ and the parameters of the SU(5) superpotential that are compatible with these and other phenomenological constraints such as the density of cold dark matter, which we assume to be provided by the lightest neutralino. Typically, these allowed regions appear for $m_0$ and $m_{1/...

  16. Spin-orbit evolution of Mercury revisited

    CERN Document Server

    Noyelles, Benoit; Makarov, Valeri; Efroimsky, Michael

    2013-01-01

    Mercury is a peculiar case, in that it is locked into the 3:2 spin-orbit resonance. Its rotation period, 58 days, is exactly two thirds of its orbital period. It is accepted that the eccentricity of Mercury (0.206) favours the trapping into this resonance. More controversial is how the capture took place. A recent study by Makarov has shown that entrapment into this resonance is certain if the eccentricity is larger than 0.2, provided that we use a realistic tidal model, based on the Darwin-Kaula expansion of the tidal torque, including both the elastic rebound and anelastic creep of solids. We here revisit the scenario of Mercury's capture into the supersynchronous spin-orbit resonances. The study is based on a realistic model of tidal friction in solids, that takes into account the rheology and the self-gravitation of the planet. Developed in Efroimsky, it was employed by Makarov et al. to determine the likely spin state of the planet GJ581d, with its eccentricity evolution taken into account. It was also u...

  17. No-scale ripple inflation revisited

    International Nuclear Information System (INIS)

    We revisit the no-scale ripple inflation model, where no-scale supergravity is modified by an additional term for the inflaton field in the Kähler potential. This term not only breaks one SU(N,1) symmetry explicitly, but also plays an important role for inflation. We generalize the superpotential in the no-scale ripple inflation model slightly. There exists a discrete Z2 symmetry/parity in the scalar potential in general, which can be preserved or violated by the non-canonical nomalized inflaton kinetic term. Thus, there are three inflation paths: one parity invariant path, and the left and right paths for parity violating scenario. We show that the inflations along the parity invariant path and right path are consistent with the Planck results. However, the gavitino mass for the parity invariant path is so large that the inflation results will be invalid if we consider the inflaton supersymmetry breaking soft mass term. Thus, only the inflation along the right path gives the correct and consistent results. Notably, the tensor-to-scalar ratio in such case can be large, with a value around 0.05, which may be probed by the future Planck experiment

  18. Searle's"Dualism Revisited"

    Energy Technology Data Exchange (ETDEWEB)

    P., Henry

    2008-11-20

    A recent article in which John Searle claims to refute dualism is examined from a scientific perspective. John Searle begins his recent article 'Dualism Revisited' by stating his belief that the philosophical problem of consciousness has a scientific solution. He then claims to refute dualism. It is therefore appropriate to examine his arguments against dualism from a scientific perspective. Scientific physical theories contain two kinds of descriptions: (1) Descriptions of our empirical findings, expressed in an every-day language that allows us communicate to each other our sensory experiences pertaining to what we have done and what we have learned; and (2) Descriptions of a theoretical model, expressed in a mathematical language that allows us to communicate to each other certain ideas that exist in our mathematical imaginations, and that are believed to represent, within our streams of consciousness, certain aspects of reality that we deem to exist independently of their being perceived by any human observer. These two parts of our scientific description correspond to the two aspects of our general contemporary dualistic understanding of the total reality in which we are imbedded, namely the empirical-mental aspect and the theoretical-physical aspect. The duality question is whether this general dualistic understanding of ourselves should be regarded as false in some important philosophical or scientific sense.

  19. Revisiting the Anatomy of the Living Heart.

    Science.gov (United States)

    Mori, Shumpei; Spicer, Diane E; Anderson, Robert H

    2016-01-01

    An understanding of the complexity of cardiac anatomy is required by all who seek, in the setting of cardiac disease, to interpret the images confronting them. Although the mysteries of cardiac structure have been extensively addressed, significant gaps continue to exist between the descriptions provided by morphologists and by those working in the clinical setting. In part, this reflects the limitations in providing 3D visualization of such a complicated organ. Current 3D imaging technology now permits visualization of the cardiac components using datasets obtained in the living individual. These advances, furthermore, demonstrate the anatomy in the setting of the heart as imaged within the thorax. It has been failure to describe the heart as it lies within the thorax that remains a major deficiency of many morphologists relying on the dissecting room to provide the gold standard. Describing the heart in attitudinally appropriate fashion, a basic rule of clinical anatomy, creates the necessary bridges between anatomists and clinicians. The rapid progression of cardiac interventional techniques, furthermore, emphasizes the need to revisit cardiac anatomy using a multidisciplinary approach. In this review, therefore, we illustrate the advantages of an attitudinally correct approach to cardiac anatomy. We then focus on the morphology of the arterial roots, revealing the accuracy that can now be achieved by clinicians using datasets obtained during life.

  20. Pair Production Constraints on Superluminal Neutrinos Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC; Gardner, Susan; /Kentucky U.

    2012-02-16

    We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint. In summary, any model for which the CG pair production process operates is excluded because such timelike neutrinos would not be detected by OPERA or other experiments. However, a superluminal neutrino which is effectively lightlike with fixed p{sup 2} can evade the Cohen-Glashow constraint because of energy-momentum conservation. The coincidence involved in explaining the SN1987A constraint certainly makes such a picture improbable - but it is still intrinsically possible. The lightlike model is appealing in that it does not violate Lorentz symmetry in particle interactions, although one would expect Hughes-Drever tests to turn up a violation eventually. Other evasions of the CG constraints are also possible; perhaps, e.g., the neutrino takes a 'short cut' through extra dimensions or suffers anomalous acceleration in matter. Irrespective of the OPERA result, Lorentz-violating interactions remain possible, and ongoing experimental investigation of such possibilities should continue.

  1. Effects of high cell density fermentations on the optimisation of mead fermentation

    OpenAIRE

    Pereira, Ana Paula; Ferreira, Alexandra Mendes; Leticia M. Estevinho; Faia, Arlete Mendes

    2012-01-01

    Mead is a traditional drink, containing 8-18% (v/v) of ethanol, which results from the alcoholic fermentation of diluted honey performed by yeasts. It has been reported that mead fermentation is a time-consuming process, often taking several months to complete, depending on the type of honey, yeast strain and honey-must’s composition. An important objective of mead makers is to reduce the fermentation time without decreasing the quality of the end product. It has been shown tha...

  2. A biochemically structured model for ethanol fermentation by Kluyveromyces marxianus: A batch fermentation and kinetic study

    DEFF Research Database (Denmark)

    Sansonetti, Sascha; Hobley, Timothy John; Calabrò, V.;

    2011-01-01

    Anaerobic batch fermentations of ricotta cheese whey (i.e. containing lactose) were performed under different operating conditions. Ethanol concentrations of ca. 22gL−1 were found from whey containing ca. 44gL−1 lactose, which corresponded to up to 95% of the theoretical ethanol yield within 15h...... ethanol, lactose, biomass and glycerol during batch fermentation could be described within a ca. 6% deviation, as could the yield coefficients for biomass and ethanol produced on lactose. The model structure confirmed that the thermodynamics considerations on the stoichiometry of the system constrain the...... metabolic coefficients within a physically meaningful range thereby providing valuable and reliable insight into fermentation processes....

  3. System for extracting protein from a fermentation product

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Jr., John Warren; Bootsma, Jason Alan; Lewis, Stephen Michael

    2016-04-26

    A method of producing bioproducts from a feedstock in a system configured to produce ethanol and distillers grains from a fermentation product is disclosed. A system configured to process feedstock into a fermentation product and bioproducts including ethanol and meal is disclosed. A bioproduct produced from a fermentation product produced from a feedstock in a biorefining system is disclosed.

  4. Method for extracting protein from a fermentation product

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Jr., John Warren; Bootsma, Jason Alan; Lewis, Stephen Michael

    2014-02-18

    A method of producing bioproducts from a feedstock in a system configured to produce ethanol and distillers grains from a fermentation product is disclosed. A system configured to process feedstock into a fermentation product and bioproducts including ethanol and meal is disclosed. A bioproduct produced from a fermentation product produced from a feedstock in a biorefining system is disclosed.

  5. Anaerobic fermentation of beef cattle manure. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, A.G.; Chen, Y.R.; Varel, V.H.

    1981-01-01

    The research to convert livestock manure and crop residues into methane and a high protein feed ingredient by thermophilic anaerobic fermentation are summarized. The major biological and operational factors involved in methanogenesis were discussed, and a kinetic model that describes the fermentation process was presented. Substrate biodegradability, fermentation temperature, and influent substrate concentration were shown to have significant effects on CH/sub 4/ production rate. The kinetic model predicted methane production rates of existing pilot and full-scale fermentation systems to within 15%. The highest methane production rate achieved by the fermenter was 4.7 L CH/sub 4//L fermenter day. This is the highest rate reported in the literature and about 4 times higher than other pilot or full-scale systems fermenting livestock manures. Assessment of the energy requirements for anaerobic fermentation systems showed that the major energy requirement for a thermophilic system was for maintaining the fermenter temperature. The next major energy consumption was due to the mixing of the influent slurry and fermenter liquor. An approach to optimizing anaerobic fermenter designs by selecting design criteria that maximize the net energy production per unit cost was presented. Based on the results, we believe that the economics of anaerobic fermentation is sufficiently favorable for farm-scale demonstration of this technology.

  6. 27 CFR 24.212 - High fermentation wine.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false High fermentation wine. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.212 High fermentation wine. High fermentation wine is wine made with the addition of sugar within the limitations...

  7. Microbe-microbe interactions in mixed culture food fermentations

    NARCIS (Netherlands)

    Smid, E.J.; Lacroix, C.

    2013-01-01

    Most known natural and industrial food fermentation processes are driven by either simple or complex communities of microorganisms. Obviously, these fermenting microbes will not only interact with the fermentable substrate but also with each other. These microbe–microbe interactions are complex but

  8. Production, characteristics and fermentation of soymilk

    Directory of Open Access Journals (Sweden)

    Rajka Božanić

    2006-12-01

    Full Text Available Interest for soybean increases because of its extraordinary nutritive and health characteristics. In West countries soymilk is intended for population that cannot consume cow’s milk, due to lactose intolerance, allergies to cow’s milk proteins or non consumption of animal foodstuffs from belief. Health benefits of soymilk increase significantly by fermentation with lactic acid bacteria. Because of that, in this paper composition of soybean is described, with special overview on proteins, lipids, and carbohydrates as well as antinutritive factors and isoflavones. Soymilk composition and production, and its nutritive value are represented also. Advantages of fermentation of soybean and soymilk are described, especially with probiotic lactic acid bacteria.

  9. Maximisation of fuel ethanol from pawpaw fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V.C.; Ayanru, D.K.G.; Ogbeide, O.N.; Okiy, D.A.

    1984-01-01

    Fermentation of slurry from pawpaw fruits (Carica papaya L.) was carried out under conditions of non-sterilization, sterilization, pasteurization, and varying concentrations of yeast cells (Saccharomyces carlsbergensis), incubation times and temperatures. For a slurry pH of 3.5, a maximum of 6.84% of ethanol was produced at yeast cell concentration of 4.3 X 10/sup 8/ cells/ml and for incubation time of ca. 24 hr at 25/sup 0/C. This value of ethanol compares well with 8-10% ethanol produced by the brewing and distilling industries by using conventional raw materials and fermentation techniques.

  10. Maximisation of fuel ethanol from pawpaw fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V.C.; Ayarnu, D.K.G.; Ogbeide, O.N.; Okiy, D.A.

    1984-01-01

    Fermentation of slurry from pawpaw fruits (Carica papaya L.) was carried out under conditions of non-sterilization, sterilization, pasteurization, and varying concentrations of yeast cells (Saccharomyces carlsbergensis), incubation times and temperatures. For a slurry pH of 3.5, a maximum of 6.84% of ethanol was produced at yeast cell concentration of 4.3 x 10 to the power of 8 cells/ml and for incubation time of ca. 24 hours at 25 degrees C. This value of ethanol compares well with 8-10% ethanol produced by the brewing and distilling industries by using conventional raw materials and fermentation techniques. (Refs. 18).

  11. Recovery of succinic acid from fermentation broth.

    Science.gov (United States)

    Kurzrock, Tanja; Weuster-Botz, Dirk

    2010-03-01

    Succinic acid is of high interest as bio-feedstock for the chemical industry. It is a precursor for a variety of many other chemicals, e.g. 1,4-butandiol, tetrahydrofuran, biodegradable polymers and fumaric acid. Besides optimized production strains and fermentation processes it is indispensable to develop cost-saving and energy-effective downstream processes to compete with the current petrochemical production process. Various methods such as precipitation, sorption and ion exchange, electrodialysis, and liquid-liquid extraction have been investigated for the recovery of succinic acid from fermentation broth and are reviewed critically here. PMID:19898782

  12. Quality and Flavor Profiles of Arabica Coffee Processed by Some Fermentation Treatments: Temperature, Containers, and Fermentation Agents Addition

    OpenAIRE

    Yusianto .; Sukrisno Widyotomo

    2013-01-01

    Coffee fermentation is a step of wet processing. In fact, some microorganisms naturally exist on the surface of coffee cherry. Using a starter culture of microorganisms may change equilibrium of microorganism population. Among some safe fermentation agents are present in “ragi tape” (yeast), “ragi tempe”, and fermented milk. A fermentor machine equipped with eating-control and stirrer had been designed, and tested before. Some treatments investigated were fermentation containers (fermentor ma...

  13. The Importance of Being a Complement: CED Effects Revisited

    Science.gov (United States)

    Jurka, Johannes

    2010-01-01

    This dissertation revisits subject island effects (Ross 1967, Chomsky 1973) cross-linguistically. Controlled acceptability judgment studies in German, English, Japanese and Serbian show that extraction out of specifiers is consistently degraded compared to extraction out of complements, indicating that the Condition on Extraction domains (CED,…

  14. Intramolecular Amide Hydrolysis in N-Methylmaleamic Acid Revisited

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The intramolecular amide hydrolysis of N-methylmaleamic acid have been revisited by use of density functional theory and inclusion of solvent effects. The results indicate that concerted reaction mechanism is favored over stepwise reaction mechanism. This is in agreement with the previous theoretical study. Sovlent effects have significant influence on the reaction barrier.

  15. Educational Administration and the Management of Knowledge: 1980 Revisited

    Science.gov (United States)

    Bates, Richard

    2013-01-01

    This paper revisits the thesis of a 1980 paper that suggested a new approach to educational administration based upon the New Sociology of Education. In particular it updates answers to the six key questions asked by that paper: what counts as knowledge; how is what counts as knowledge organised; how is what counts as knowledge transmitted; how is…

  16. The Polarized Structure Function $g_{2} A Lattice Study Revisited

    CERN Document Server

    Göckeler, M; Kürzinger, W; Oelrich, H; Rakow, P; Schierholz, G

    1999-01-01

    A recent lattice calculation of the spin-dependent structure function g_2 is revisited. It has been recognized that the twist-three operator, which gives rise to d_2, mixes non-perturbatively with operators of lower dimensions under renormalization. This changes the results substantially.

  17. "An analysis of the classical Doppler Effect"[1] revisited

    OpenAIRE

    Rothenstein, Bernhard; Nafornita, Corina

    2004-01-01

    After having shown that the formula which describes the Doppler effect in the general case holds only in the case of the "very high" frequency assumption, we derive free of assumptions Doppler formulas for two scenarios presented in the revisited paper.

  18. Revisiting Mental Simulation in Language Comprehension: Six Replication Attempts

    NARCIS (Netherlands)

    R.A. Zwaan (Rolf); D. Pecher (Diane)

    2012-01-01

    textabstractThe notion of language comprehension as mental simulation has become popular in cognitive science. We revisit some of the original empirical evidence for this. Specifically, we attempted to replicate the findings from earlier studies that examined the mental simulation of object orientat

  19. Complex and detailed balancing of chemical reaction networks revisited

    NARCIS (Netherlands)

    van der Schaft, Abraham; Rao, Shodhan; Jayawardhana, Bayu

    2015-01-01

    The characterization of the notions of complex and detailed balancing for mass action kinetics chemical reaction networks is revisited from the perspective of algebraic graph theory, in particular Kirchhoff’s Matrix Tree theorem for directed weighted graphs. This yields an elucidation of previously

  20. Coccolithophores in Polar Waters: Papposphaera arctica HET and HOL revisited

    DEFF Research Database (Denmark)

    Thomsen, Helge Abildhauge; Heldal, Mikal; Østergaard, Jette B.

    2016-01-01

    It has been generally accepted based on the finding of combination coccospheres in field samples that Turrisphaera arctica and Papposphaera sarion are alternate life-cycle phases of a single species. However, while recently revisiting P. sarion it became evident that the Turrisphaera phase of thi...

  1. Closing Achievement Gaps: Revisiting Benjamin S. Bloom's "Learning for Mastery"

    Science.gov (United States)

    Guskey, Thomas R.

    2007-01-01

    The problem of achievement gaps among different subgroups of students has been evident in education for many years. This manuscript revisits the work of renowned educator Benjamin S. Bloom, who saw reducing gaps in the achievement of various groups of students as a simple problem of reducing variation in student learning outcomes. Bloom observed…

  2. A control center design revisited: learning from users’ appropriation

    DEFF Research Database (Denmark)

    Souza da Conceição, Carolina; Cordeiro, Cláudia

    2014-01-01

    This paper aims to present the lessons learned during a control center design project by revisiting another control center from the same company designed two and a half years before by the same project team. In light of the experience with the first project and its analysis, the designers and res...

  3. Bohr’s ‘Light and Life’ revisited

    Science.gov (United States)

    Nussenzveig, H. M.

    2015-11-01

    I revisit Niels Bohr’s famous 1932 ‘Light and Life’ lecture, confronting it with current knowledge. Topics covered include: life origin and evolution, quantum mechanics and life, brain and mind, consciousness and free will, and light as a tool for biology, with special emphasis on optical tweezers and their contributions to biophysics. Specialized knowledge of biology is not assumed.

  4. Dynamics of Shape Fluctuations of Quasi-spherical Vesicles Revisited

    DEFF Research Database (Denmark)

    Miao, L.; Lomholt, Michael Andersen; Kleis, J.

    2002-01-01

    In this paper, the dynamics of spontaneous shape fluctuations of a single, giant quasi-spherical vesicle formed from a single lipid species is revisited theoretically. A coherent physical theory for the dynamics is developed based on a number of fundamental principles and considerations, and a sy...

  5. Additively homomorphic encryption with a double decryption mechanism, revisited

    NARCIS (Netherlands)

    Peter, A.; Kronberg, M.; Trei, W.; Katzenbeisser, S.

    2012-01-01

    We revisit the notion of additively homomorphic encryption with a double decryption mechanism (DD-PKE), which allows for additions in the encrypted domain while having a master decryption procedure that can decrypt all properly formed ciphertexts by using a special master secret. This type of encryp

  6. Revisiting the Role of Organizational Effectiveness in Educational Evaluation.

    Science.gov (United States)

    Lotto, Linda S.

    Organizational effectiveness ought to play a role in educational evaluation, and the development of alternative perspectives for viewing organizations could be a starting point for revisiting organizational evaluation in education. Five possible perspectives and criteria for evaluating organizations have been developed. If an organization is…

  7. Keep Moving! Revisiting Thumbnails for Mobile Video Retrieval

    NARCIS (Netherlands)

    W. Hürst; C.G.M. Snoek; W.J. Spoel; M. Tomin

    2010-01-01

    Motivated by the increasing popularity of video on handheld devices and the resulting importance for effective video retrieval, this paper revisits the relevance of thumbnails in a mobile video retrieval setting. Our study indicates that users are quite able to handle and assess small thumbnails on

  8. Clostridium sticklandii, a specialist in amino acid degradation:revisiting its metabolism through its genome sequence

    Directory of Open Access Journals (Sweden)

    Pelletier Eric

    2010-10-01

    Full Text Available Abstract Background Clostridium sticklandii belongs to a cluster of non-pathogenic proteolytic clostridia which utilize amino acids as carbon and energy sources. Isolated by T.C. Stadtman in 1954, it has been generally regarded as a "gold mine" for novel biochemical reactions and is used as a model organism for studying metabolic aspects such as the Stickland reaction, coenzyme-B12- and selenium-dependent reactions of amino acids. With the goal of revisiting its carbon, nitrogen, and energy metabolism, and comparing studies with other clostridia, its genome has been sequenced and analyzed. Results C. sticklandii is one of the best biochemically studied proteolytic clostridial species. Useful additional information has been obtained from the sequencing and annotation of its genome, which is presented in this paper. Besides, experimental procedures reveal that C. sticklandii degrades amino acids in a preferential and sequential way. The organism prefers threonine, arginine, serine, cysteine, proline, and glycine, whereas glutamate, aspartate and alanine are excreted. Energy conservation is primarily obtained by substrate-level phosphorylation in fermentative pathways. The reactions catalyzed by different ferredoxin oxidoreductases and the exergonic NADH-dependent reduction of crotonyl-CoA point to a possible chemiosmotic energy conservation via the Rnf complex. C. sticklandii possesses both the F-type and V-type ATPases. The discovery of an as yet unrecognized selenoprotein in the D-proline reductase operon suggests a more detailed mechanism for NADH-dependent D-proline reduction. A rather unusual metabolic feature is the presence of genes for all the enzymes involved in two different CO2-fixation pathways: C. sticklandii harbours both the glycine synthase/glycine reductase and the Wood-Ljungdahl pathways. This unusual pathway combination has retrospectively been observed in only four other sequenced microorganisms. Conclusions Analysis of the C

  9. Complex media from processing of agricultural crops for microbial fermentation

    DEFF Research Database (Denmark)

    Thomsen, M.H.

    2005-01-01

    examples of such products-polylactic acid and L-lysine-are given. A cost calculation shows that this fermentation medium can be produced at a very low cost approximate to 1.7 Euro cent/kg, when taking into account that the green crop industry has expenses amounting to 270,000 Euro/year for disposal......, is converted to a basic, universal fermentation medium by lactic acid fermentation, is outlined. The resulting all-round fermentation medium can be used for the production of many useful fermentation products when added a carbohydrate source, which could possibly be another agricultural by-product. Two...

  10. Prediction of the production kinetics of the main fermentative aromas in winemaking fermentations

    OpenAIRE

    Mouret, Jean-Roch; Farines, Vincent; Sablayrolles, Jean-Marie; Trelea, Ioan-Cristian

    2015-01-01

    A novel dynamic model was developed for predicting the synthesis kinetics of the principal aroma compounds produced by yeasts during winemaking fermentations: isobutanol, isoamyl alcohol, isoamyl acetate, ethyl hexanoate and ethyl octanoate. The parameters of the model were identified from nine fermentations performed at temperatures between 18 and 30 degrees C and with different initial nitrogen contents, in the range of 70 to 410 mgN/L. The model was validated in six independent experiments...

  11. Influence of Tarhana Herb (Echinophora sibthorpiana) on Fermentation of Tarhana, Turkish Traditional Fermented Food

    OpenAIRE

    Deghirmencioghlu, Nurcan; Göçmen, Duygu; Daghdelen, Ayhan; Daghdelen, Fatih

    2005-01-01

    Tarhana herb (Echinophora sibthorpiana) (TH) is used as a spice in tarhana. It has a pleasant flavour and stimulates some microorganisms. In this study, the fermentation activity of tarhana was investigated by monitoring the lactic acid bacteria (LAB) and yeast populations when TH was used as additive. It can be said that tarhana herb (Echinophora sibthorpiana) prevented the decrease in the counts of LAB and yeast below the initial number during tarhana fermentation.

  12. Studies on the kinetics of alcoholic fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Godia i Casablancas, F.; Casas Alvero, C.; Sola Ferrando, C.

    1984-01-01

    Yeast isolated from a must was used to ferment a medium containing 50, 98, 150, or 188 g glucose L and the kinetics of cell growth, EtOH formation, and glucose utilization were determined. The results did not agree with the results obtained using 9 different model equations. The models are therefore unsatisfactory.

  13. Fermentation and oxygen transfer in microgravity

    Science.gov (United States)

    Dunlop, Eric H.

    1989-01-01

    The need for high rate oxygen transfer in microgravity for a Controlled Ecological Life Support System (CELSS) environment offers a number of difficulties and challenges. The use of a phase separated bioreactor appears to provide a way of overcoming these problems resulting in a system capable of providing high cell densities with rapid fermentation rates. Some of the key design elements are discussed.

  14. Enzymatic and bacterial conversions during sourdough fermentation.

    Science.gov (United States)

    Gänzle, Michael G

    2014-02-01

    Enzymatic and microbial conversion of flour components during bread making determines bread quality. Metabolism of sourdough microbiota and the activity of cereal enzymes are interdependent. Acidification, oxygen consumption, and thiols accumulation by microbial metabolism modulate the activity of cereal enzymes. In turn, cereal enzymes provide substrates for bacterial growth. This review highlights the role of cereal enzymes and the metabolism of lactic acid bacteria in conversion of carbohydrates, proteins, phenolic compounds and lipids. Heterofermentative lactic acid bacteria prevailing in wheat and rye sourdoughs preferentially metabolise sucrose and maltose; the latter is released by cereal enzymes during fermentation. Sucrose supports formation of acetate by heterofermentative lactobacilli, and the formation of exopolysaccharides. The release of maltose and glucose by cereal enzymes during fermentation determines the exopolysaccharide yield in sourdough fermentations. Proteolysis is dependent on cereal proteases. Peptidase activities of sourdough lactic acid bacteria determine the accumulation of (bioactive) peptides, amino acids, and amino acid metabolites in dough and bread. Enzymatic conversion and microbial metabolism of phenolic compounds is relevant in sorghum and millet containing high levels of phenolic compounds. The presence of phenolic compounds with antimicrobial activity in sorghum selects for fermentation microbiota that are resistant to the phenolic compounds.

  15. Enzymatic and bacterial conversions during sourdough fermentation.

    Science.gov (United States)

    Gänzle, Michael G

    2014-02-01

    Enzymatic and microbial conversion of flour components during bread making determines bread quality. Metabolism of sourdough microbiota and the activity of cereal enzymes are interdependent. Acidification, oxygen consumption, and thiols accumulation by microbial metabolism modulate the activity of cereal enzymes. In turn, cereal enzymes provide substrates for bacterial growth. This review highlights the role of cereal enzymes and the metabolism of lactic acid bacteria in conversion of carbohydrates, proteins, phenolic compounds and lipids. Heterofermentative lactic acid bacteria prevailing in wheat and rye sourdoughs preferentially metabolise sucrose and maltose; the latter is released by cereal enzymes during fermentation. Sucrose supports formation of acetate by heterofermentative lactobacilli, and the formation of exopolysaccharides. The release of maltose and glucose by cereal enzymes during fermentation determines the exopolysaccharide yield in sourdough fermentations. Proteolysis is dependent on cereal proteases. Peptidase activities of sourdough lactic acid bacteria determine the accumulation of (bioactive) peptides, amino acids, and amino acid metabolites in dough and bread. Enzymatic conversion and microbial metabolism of phenolic compounds is relevant in sorghum and millet containing high levels of phenolic compounds. The presence of phenolic compounds with antimicrobial activity in sorghum selects for fermentation microbiota that are resistant to the phenolic compounds. PMID:24230468

  16. Fermentative production of carotenoids from marine actinomycetes

    Directory of Open Access Journals (Sweden)

    B Ashokkumar

    2009-12-01

    Full Text Available Background and Objectives: In marine actinomycetes, carotenoid production occurs in constitutive, light-dependent or cryptic manner. The present work deals with the fermentative production of carotenoids from marine actinomycetes."nMaterials and Methods: Marine actinomycetes namely Streptomyces strain AQBMM35 was isolated from the marine sponge Mycale mytilorum collected from South West coast of India using ISP media. The Streptomyces isolates were characterized for their colony characteristics, morphological properties, physiological and biochemical properties and were tentatively identified. Fermentation of the strain under fluorescent white light was carried out for the production of carotenoids. UV spectrum, TLC and HPLC analysis were done for the confirmation of carotenoids."nResults: The characteristics studied strongly suggest that the strain AQBMM35 belongs to the genus Streptomyces sp. It has been found that Streptomyces strain (AQBMM35 fermenting under fluorescent white light produced carotenoids. Spectrophotometric analysis of the carotenoid fraction revealed a peak at 280 nm. TLC analysis of the carotenoid extract showed the presence of phytoene (Rf of 0.81. HPLC confirmed the production of phytoene when compared with standards."nConclusion: The fermenting sponge-associated Streptomyces isolate (AQBMM35 produced carotenoids namely phytoene. If this symbiotic Streptomyces strain, from which secondary metabolite like carotenoids are derived, can be cultured under light, then it can be used for mass production of precursor pigment and it can be used as an antioxidant and also as a food additive.

  17. Developments and constraints in fermentative hydrogen production

    NARCIS (Netherlands)

    Bartacek, J.; Zabranska, J.; Lens, P.N.L.

    2007-01-01

    Fermentative hydrogen production is a novel aspect of anaerobic digestion. The main advantage of hydrogen is that it is a clean and renewable energy source/carrier with high specific heat of combustion and no contribution to the Greenhouse effect, and can be used in many industrial applications. Thi

  18. Daqu - a traditional Chinese liquor fermentation starter

    NARCIS (Netherlands)

    Zheng, X.; Rezaei Tabrizi, M.; Nout, M.J.R.; Han, B.

    2011-01-01

    Chinese liquor is one of the world's oldest distilled alcoholic beverages, and it is typically obtained with the use of Daqufermentation starters. Daqu is a saccharifying and fermenting agent, having a significant impact on the flavour of the product. Daqucan be categorized according to maximum incu

  19. Modelling Fungal Fermentations for Enzyme Production

    DEFF Research Database (Denmark)

    Albæk, Mads Orla; Gernaey, Krist; Hansen, Morten S.;

    We have developed a process model of fungal fed-batch fermentations for enzyme production. In these processes, oxygen transfer rate is limiting and controls the substrate feeding rate. The model has been shown to describe cultivations of both Aspergillus oryzae and Trichoderma reesei strains in 550...

  20. Backwardation in energy futures markets: Metalgesellschaft revisited

    International Nuclear Information System (INIS)

    Energy supply contracts negotiated by the US Subsidiary of Metalgesellschaft Refining and Marketing (MGRM), which were the subject of much subsequent debate, are re-examined. The contracts were hedged by the US Subsidiary barrel-for-barrel using short-dated energy derivatives. When the hedge program experienced difficulties, the derivatives positions were promptly liquidated by the parent company. Revisiting the MGRM contracts also provides the opportunity to explore the latest evidence on backwardation in energy markets. Accordingly, the paper discusses first the theoretical reasons for backwardation, followed by an empirical examination using the MGRM data available at the time of the hedge program in 1992 and a second set of data that became available in 2000. By using a more up-to-date data set covering a longer time period and by controlling the time series properties of the data, the authors expect to provide more reliable empirical evidence on the behaviour of energy futures prices. Results based on the 1992 data suggest that the strategy employed by MGRM could be expected to be profitable while the risks are relatively low. However, analysis based on the 2000 data shows lower, although still significant profits, but higher risks. The final conclusion was that the likelihood of problems similar to those faced by MGRM in 1992 are twice as high with the updated 2000 data, suggesting that the risk-return pattern of the stack-and-roll hedging strategy using short-dated energy future contracts to hedge long-tem contracts is less appealing now than when MGRM implemented its hedging program in 1992. 24 refs., 3 tabs., 6 figs

  1. Functional Characterization of Bacterial Communities Responsible for Fermentation of Doenjang: A Traditional Korean Fermented Soybean Paste

    Science.gov (United States)

    Jung, Woo Yong; Jung, Ji Young; Lee, Hyo Jung; Jeon, Che Ok

    2016-01-01

    Doenjang samples were prepared in triplicate and their microbial abundance, bacterial communities, and metabolites throughout fermentation were analyzed to investigate the functional properties of microorganisms in doenjang. Viable bacterial cells were approximately three orders of magnitude higher than fungal cells, suggesting that bacteria are more responsible for doenjang fermentation. Pyrosequencing and proton nuclear magnetic resonance spectroscopy were applied for the analysis of bacterial communities and metabolites, respectively. Bacterial community analysis based on 16S rRNA gene sequences revealed that doenjang samples included Bacillus, Enterococcus, Lactobacillus, Clostridium, Staphylococcus, Corynebacterium, Oceanobacillus, and Tetragenococcus. These genera were found either in doenjang-meju or solar salts, but not in both, suggesting two separate sources of bacteria. Bacillus and Enterococcus were dominant genera during the fermentation, but their abundances were not associated with metabolite changes, suggesting that they may not be major players in doenjang fermentation. Tetragenococcus was dominant in 108 day-doenjang samples, when lactate, acetate, putrescine, and tyramine increased quickly as glucose and fructose decreased, indicating that Tetragenococcus might be primarily responsible for organic acid and biogenic amine production. Lactobacillus was identified as a dominant group from the 179-day samples, associated with the increase of γ-aminobutyric acid (GABA) and the decrease of galactose, indicating a potential role for this genus as a major GABA producer during fermentation. The results of this study clarified the functional properties of major bacterial communities in the doenjang fermentation process, contributing to the production of safe and high-quality doenjang. PMID:27303399

  2. Functional Characterization of Bacterial Communities Responsible for Fermentation of Doenjang: A Traditional Korean Fermented Soybean Paste.

    Science.gov (United States)

    Jung, Woo Yong; Jung, Ji Young; Lee, Hyo Jung; Jeon, Che Ok

    2016-01-01

    Doenjang samples were prepared in triplicate and their microbial abundance, bacterial communities, and metabolites throughout fermentation were analyzed to investigate the functional properties of microorganisms in doenjang. Viable bacterial cells were approximately three orders of magnitude higher than fungal cells, suggesting that bacteria are more responsible for doenjang fermentation. Pyrosequencing and proton nuclear magnetic resonance spectroscopy were applied for the analysis of bacterial communities and metabolites, respectively. Bacterial community analysis based on 16S rRNA gene sequences revealed that doenjang samples included Bacillus, Enterococcus, Lactobacillus, Clostridium, Staphylococcus, Corynebacterium, Oceanobacillus, and Tetragenococcus. These genera were found either in doenjang-meju or solar salts, but not in both, suggesting two separate sources of bacteria. Bacillus and Enterococcus were dominant genera during the fermentation, but their abundances were not associated with metabolite changes, suggesting that they may not be major players in doenjang fermentation. Tetragenococcus was dominant in 108 day-doenjang samples, when lactate, acetate, putrescine, and tyramine increased quickly as glucose and fructose decreased, indicating that Tetragenococcus might be primarily responsible for organic acid and biogenic amine production. Lactobacillus was identified as a dominant group from the 179-day samples, associated with the increase of γ-aminobutyric acid (GABA) and the decrease of galactose, indicating a potential role for this genus as a major GABA producer during fermentation. The results of this study clarified the functional properties of major bacterial communities in the doenjang fermentation process, contributing to the production of safe and high-quality doenjang. PMID:27303399

  3. Study on Incentive Price of Fermented Cocoa to Overcome Reluctance of Farmer to Apply Fermentation : Case Study in Jembrana Regency

    Directory of Open Access Journals (Sweden)

    Joko Soemarno

    2015-08-01

    Full Text Available Improving cocoa quality through encouraging farmers to do fermentation is one of the ways to increase the added value of cocoa. However, majority ofIndonesian farmers are reluctance to do fermentation. This research aimed to study factors causing farmers reluctant to do fermentation, weight differencebetween fermented and unfermented cocoa, cocoa processing time difference between fermented and unfermented cocoa, quality difference between fermentedand unfermented coco refers to cocoa bean standard (SNI: 01-2323-2008/Amd-2010, and feasible added value incentive of fermented cocoa beans. The data collectionwere conducted through household farmers’ survey, focus group discussion and experimental research. The experimental research was conducted to understandthe weight and processing time differences; and to asess the quality, including moisture content, bean count, pH and fermentation index. Analysis of the datawere conducted by methods of Fishbone Ishikawa and logit multiplier linear analysis. The research results showed that the main factors causing farmers reluctant todo fermentation were insuitable of selling price of fermented cocoa, the existence of village collectors in buying unfermented cocoa, the lack of cooperation amongfarmers in farmer group (Subak Abian and the lack of farmers’ skills on cocoa bean fermentation. This study also found that the weight depreciation differencebetween fermented and unfermented cocoa was 0.5-3.75%, and the processing time difference between fermented and unfermented cocoa was 12-24 hours. Qualityof fermented cocoa beans was higher than that of unfermented cocoa beans and it can fulfill the standard of SNI: 01-2323-2008/Amd-2010. It was found that thefeasible added value incentive of fermented cocoa benas was 2,126-3,426 IDR/kg. Keywords: cocoa, fermentation, unfermented, quality, incentive

  4. Effect of fermented Banana peel on Broiler Carcass

    Directory of Open Access Journals (Sweden)

    Koni TNI

    2013-06-01

    Full Text Available This experiment was conducted to examine effect of inclusion of fermented banana peel by Rhyzopus oligosporus in diets on slaughter weight, carcass weight and carcass percentage, weight and percentage abdominal fat of broiler. The experiment was done based on Completely Randomized Design with four treatments and four replications and each replication consisted of six chickens. The treatment were R0 = without banana peel fermented, R1 = 5% banana peel fermented, R2 = 10% banana peel fermented, R3 = 15% banana peel fermented. Data of the experiment were analyzed, using ANOVA and then continued with Duncan's Multiple Range Test. Result showed that level of fermented banana peel affected slaughter weight and carcass weight. However carcass persentage, weight and percentage of abdominal fat was not affected by treatment. Banana peel fermented by Rhizopus oligosporus could can be used maximally 10% in broiler ration.

  5. Increased flavour diversity of Chardonnay wines by spontaneous fermentation and co-fermentation with Hanseniaspora vineae.

    Science.gov (United States)

    Medina, K; Boido, E; Fariña, L; Gioia, O; Gomez, M E; Barquet, M; Gaggero, C; Dellacassa, E; Carrau, F

    2013-12-01

    Discovery, characterisation and use of novel yeast strains for winemaking is increasingly regarded as a way for improving quality and to provide variation, including subtle characteristic differences in fine wines. The objective of this work was to evaluate the use of a native apiculate strain, selected from grapes, Hanseniaspora vineae (H. vineae) 02/5A. Fermentations were done in triplicate, working with 225 L oak barrels, using a Chardonnay grape must. Three yeast fermentation strategies were compared: conventional inoculation with a commercial Saccharomyces cerevisiae strain, ALG 804, sequential inoculation with H. vineae and then strain ALG 804 and spontaneous fermentation. Yeast strain identification was performed during fermentation, in which the apiculate strain was found to be active, until 9% of alcohol in volume, for the co-fermentation and the spontaneous fermentation was completed by three native S. cerevisiae strains. Basic winemaking parameters and some key chemical analysis, such as concentration of glycerol, biogenic amines, organic acids, and aroma compounds were analysed. Sensory analysis was done using a trained panel and further evaluated with professional winemakers. Sequential inoculation with H. vineae followed by S. cerevisiae resulted in relatively dry wines, with increased aroma and flavour diversity compared with wines resulting from inoculation with S. cerevisiae alone. Wines produced from sequential inoculations were considered, by a winemaker's panel, to have an increased palate length and body. Characteristics of wines derived from sequential inoculation could be explained due to significant increases in glycerol and acetyl and ethyl ester flavour compounds and relative decreases in alcohols and fatty acids. Aroma sensory analysis of wine character and flavour, attributed to winemaking using H. vineae, indicated a significant increase in fruit intensity described as banana, pear, apple, citric fruits and guava. GC analysis of the

  6. Fermentation to ethanol of pentose-containing spent sulphite liquor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.; Wayman, M.; Parekh, S.K.

    1987-06-01

    Ethanolic fermentation of spent sulphite liquor with ordinary bakers' yeast is incomplete because this yeast cannot ferment the pentose sugars in the liquor. This results in poor alcohol yields, and a residual effluent problem. By using the yeast Candida shehatae (R) for fermentation of the spent sulphite liquor from a large Canadian alcohol-producing sulphite pulp and paper mill, pentoses as well as hexoses were fermented nearly completely, alcohol yields were raised by 33%, and sugar removal increased by 46%. Inhibitors were removed prior to fermentation by steam stripping. Major benefits were obtained by careful recycling of this yeast, which was shown to be tolerant both of high sugar concentrations and high alcohol concentrations. When sugar concentrations over 250 g/L (glucose:xylose 70:30) were fermented, ethanol became an inhibitor when its concentration reached 90 g/L. However, when the ethanol was removed by low-temperature vacuum distillation, fermentation continued and resulted in a yield of 0.50 g ethanol/g sugar consumed. Further improvement was achieved by combining enzyme saccharification of sugar oligomers with fermentation. This yeast is able to ferment both hexoses and pentoses simultaneously, efficiently, and rapidly. Present indications are that it is well suited to industrial operations wherever hexoses and pentoses are both to be fermented to ethanol, for example, in wood hydrolysates. (Refs. 6).

  7. High throughput biotechnology in traditional fermented food industry.

    Science.gov (United States)

    Yang, Yong; Xu, Rong-man; Song, Jia; Wang, Wei-min

    2010-11-01

    Traditional fermented food is not only the staple food for most of developing countries but also the key healthy food for developed countries. As the healthy function of these foods are gradually discovered, more and more high throughput biotechnologies are being used to promote the old and new industry. As a result, the microflora, manufacturing processes and product healthy function of these foods were pushed forward either in the respect of profundity or extensiveness nowadays. The application and progress of the high throughput biotechnologies into traditional fermented food industries were different from each other, which was reviewed and detailed by the catalogues of fermented milk products (yogurt, cheese), fermented sausages, fermented vegetables (kimchi, sauerkraut), fermented cereals (sourdough) and fermented beans (tempeh, natto). Given the further promotion by high throughput biotechnologies, the middle and/or down-stream process of traditional fermented foods would be optimized and the process of industrialization of local traditional fermented food having many functional factors but in small quantity would be accelerated. The article presents some promising patents on traditional fermented food industry. PMID:20863273

  8. Solid Substrate Fermentation of Cassava Peel for Poultry Feed Ingredient

    Directory of Open Access Journals (Sweden)

    Stephanie

    2013-03-01

    Full Text Available Cassava peel which is not used during cassava starch extraction is one of potential resources for animal feed. However, cassava peel has low level protein content, high level crude fiber, and high level of toxic cyanogenic compound. These problems limit the utilization of cassava peel as feed. Solid substrate fermentation using mold may be a solution process to increase its nutritional value and decrease toxic level of cassava peel. In this paper, matters that related with cassava peel fermentation process are subsequently described, namely: (i problems of cassava peel; (ii biodegradation and detoxification process; (iii solid state fermentation methods on cassava peel; (iv nutritional quality of fermented cassava peel; and (v application of fermented cassava peel in poultry feed. The fermented cassava peel application is compared with those of cassava root and waste (onggok. Addition of nitrogen inorganic in the fermentation process increases the mold growth and protein content of the product, while fiber and cyanogenic contents are decreased due to mold degradation activity. The fermentation process may be carried out using only the cassava peel as the substrate or mixed with wheat flour, using indigenous microbes, Aspergillus niger or a white rot fungus, Panus tigrinus as inoculum. As well as fermented cassava root and waste, fermented cassava peel can be used to substitute maize as poultry feed, although it is reported that the optimum substitution in broiler ration is only 10%.

  9. Nuclear non-proliferation: Revisiting the basics

    International Nuclear Information System (INIS)

    The 1970 Treaty on the Non- Proliferation of Nuclear Weapons (NPT), with 188 States party, represents the cornerstone of the global nuclear non-proliferation and disarmament effort -- and despite recent challenges, it has never been more relevant than it is today. But if we are to move forward, it is essential to revisit a number of the basic assumptions and features of the existing regime, and consider a number of new approaches. A key assumption at the core of the NPT was that the asymmetry between nuclear-weapon States and non-nuclear-weapon States would gradually disappear. Progress has been made on the nuclear disarmament front, but much more remains to be done. Nuclear disarmament strategies have for the most part focused on the negotiation of bilateral nuclear arms control agreements between the holders of the two largest nuclear arsenals, and a few multilateral agreements designed to curb the quantitative and qualitative development of nuclear weapons. With the end of the Cold War as an impetus, some progress was made in the early and mid-1990s, but the process unfortunately slowed in the latter part of the decade. The discoveries of a clandestine nuclear weapon programme in Iraq after the 1991 Gulf War made it painfully clear that the IAEA verification system, with its focus on declared nuclear activities and its limited rights of access to information and sites, was not adequate for the IAEA to provide the comprehensive peaceful use assurances required under the NPT. This stark realization prompted the international community to significantly expand the IAEA's verification rights. These new rights were incorporated into a 1997 protocol additional to safeguards agreements, with a request for all States to subscribe to it. For the IAEA to provide the required assurances, it must have the required authority. It is clear that the success of the IAEA verification regime will depend heavily on achieving universal adherence to the required safeguards agreements

  10. Safety assessment of the biogenic amines in fermented soya beans and fermented bean curd.

    Science.gov (United States)

    Yang, Juan; Ding, Xiaowen; Qin, Yingrui; Zeng, Yitao

    2014-08-01

    To evaluate the safety of biogenic amines, high performance liquid chromatography (HPLC) was used to evaluate the levels of biogenic amines in fermented soya beans and fermented bean curd. In fermented soya beans, the total biogenic amines content was in a relatively safe range in many samples, although the concentration of histamine, tyramine, and β-phenethylamine was high enough in some samples to cause a possible safety threat, and 8 of the 30 samples were deemed unsafe. In fermented bean curd, the total biogenic amines content was more than 900 mg/kg in 19 white sufu amples, a level that has been determined to pose a safety hazard; putrescine was the only one detected in all samples and also had the highest concentration, which made samples a safety hazard; the content of tryptamine, β-phenethylamine, tyramine, and histamine had reached the level of threat to human health in some white and green sufu samples, and that may imply another potential safety risk; and 25 of the 33 samples were unsafe. In conclusion, the content of biogenic amines in all fermented soya bean products should be studied and appropriate limits determined to ensure the safety of eating these foods.

  11. Volatile components and sensory characteristics of Thai traditional fermented shrimp pastes during fermentation periods.

    Science.gov (United States)

    Kleekayai, Thanyaporn; Pinitklang, Surapong; Laohakunjit, Natta; Suntornsuk, Worapot

    2016-03-01

    Headspace-volatile components and sensory characteristics, including color, Maillard reaction products and free amino acid profiles, of two types of Thai traditional fermented shrimp paste, Kapi Ta Dam and Kapi Ta Deang, were investigated during the fermentation periods up to 6 months. The results showed that the colors of both products were changed with a decrease in CIELAB values over the fermentation period, except for yellowness of Kapi Ta Deang. Essential amino acids such as lysine and leucine and non-essential amino acids such as glutamic acid and alanine were found to be predominant free-amino acids in the products. After headspace volatile component extraction of the product was carried out using a SPME fiber coated with DVB/CAR/PDMS and analyzed by GC-MS, the main compounds responsible for distinct volatiles in the products were N-containing compounds, especially pyrazines which give roasted nutty odor. The results of sensory evaluation from panelists also suggest that fermentation period had an effect on sensory characteristics of the fermented shrimp pastes. Moreover, the sensory perceptions of the products would associate with their color, the Maillard reaction products, amino acid profiles and volatile compounds. PMID:27570264

  12. Safety assessment of the biogenic amines in fermented soya beans and fermented bean curd.

    Science.gov (United States)

    Yang, Juan; Ding, Xiaowen; Qin, Yingrui; Zeng, Yitao

    2014-08-01

    To evaluate the safety of biogenic amines, high performance liquid chromatography (HPLC) was used to evaluate the levels of biogenic amines in fermented soya beans and fermented bean curd. In fermented soya beans, the total biogenic amines content was in a relatively safe range in many samples, although the concentration of histamine, tyramine, and β-phenethylamine was high enough in some samples to cause a possible safety threat, and 8 of the 30 samples were deemed unsafe. In fermented bean curd, the total biogenic amines content was more than 900 mg/kg in 19 white sufu amples, a level that has been determined to pose a safety hazard; putrescine was the only one detected in all samples and also had the highest concentration, which made samples a safety hazard; the content of tryptamine, β-phenethylamine, tyramine, and histamine had reached the level of threat to human health in some white and green sufu samples, and that may imply another potential safety risk; and 25 of the 33 samples were unsafe. In conclusion, the content of biogenic amines in all fermented soya bean products should be studied and appropriate limits determined to ensure the safety of eating these foods. PMID:25029555

  13. Optimal design of pre-fermentation and fermentation stages applying nonlinear programming

    International Nuclear Information System (INIS)

    Highlights: • Simultaneous synthesis, design and operation of fermentation networks are addressed. • A superstructure NLP model is presented. • Ethanol production from molasses and hydrolyzed sugar cane bagasse is proposed. • Different tradeoffs between design and operating variables can be evaluated. - Abstract: In the present work, the optimal design of pre-fermentation and fermentation operations for ethanol production is obtained developing a superstructure mathematical model. Different configurations of both operations are simultaneously considered in an overall model which also includes detailed kinetics equations. The zero wait is the transfer policy selected for these stages for ensuring the quality of these operations, given the nature and characteristics of microbiological sugary substrates. From the overall proposed model, the optimal configuration of the stages, the number of duplicated units in each stage, the size of each process unit, the process variables as concentrations and flows, and the total investment and production cost are obtained. This model is formulated as a non-linear programming problem, which is solved by the Professional Software, General Algebraic Modeling System (GAMS) with the application of CONOPT solver. The optimal design and operation of pre-fermentation and fermentation stages are obtained and the attained results are compared with the structures in conventional distillery

  14. Production of clean pyrolytic sugars for fermentation.

    Science.gov (United States)

    Rover, Marjorie R; Johnston, Patrick A; Jin, Tao; Smith, Ryan G; Brown, Robert C; Jarboe, Laura

    2014-06-01

    This study explores the separate recovery of sugars and phenolic oligomers produced during fast pyrolysis with the effective removal of contaminants from the separated pyrolytic sugars to produce a substrate suitable for fermentation without hydrolysis. The first two stages from a unique recovery system capture "heavy ends", mostly water-soluble sugars and water-insoluble phenolic oligomers. The differences in water solubility can be exploited to recover a sugar-rich aqueous phase and a phenolic-rich raffinate. Over 93 wt % of the sugars is removed in two water washes. These sugars contain contaminants such as low-molecular-weight acids, furans, and phenols that could inhibit successful fermentation. Detoxification methods were used to remove these contaminants from pyrolytic sugars. The optimal candidate is NaOH overliming, which results in maximum growth measurements with the use of ethanol-producing Escherichia coli.

  15. Third Generation Biofuels via Direct Cellulose Fermentation

    Directory of Open Access Journals (Sweden)

    David B. Levin

    2008-07-01

    Full Text Available Consolidated bioprocessing (CBP is a system in which cellulase production, substrate hydrolysis, and fermentation are accomplished in a single process step by cellulolytic microorganisms. CBP offers the potential for lower biofuel production costs due to simpler feedstock processing, lower energy inputs, and higher conversion efficiencies than separate hydrolysis and fermentation processes, and is an economically attractive near-term goal for “third generation” biofuel production. In this review article, production of third generation biofuels from cellulosic feedstocks will be addressed in respect to the metabolism of cellulolytic bacteria and the development of strategies to increase biofuel yields through metabolic engineering.

  16. The role of brand destination experience in determining revisit intention

    DEFF Research Database (Denmark)

    Mattsson, Jan; Barnes, Stuart; Sørensen, Flemming

    experience, which provides a more holistic and unified view of the brand destination. The research uses a logistic regression model to determine the role of satisfaction and brand experience in determining revisit intentions. The study also examines differences among subgroups and four brand experience sub......-constructs. The findings suggest that brand experience is an important determinant of revisit intentions, but that there is variation among respondent groups. The paper rounds off with conclusions and implications for research and practice.......Destination branding has developed considerably as a topic area in the last decade with numerous conceptualizations focusing on different aspects of the brand. However, a unified view has not yet emerged. This paper examines destination branding via a new conceptualization, brand destination...

  17. Enthalpy-Entropy Compensation (EEC) Effect: A Revisit.

    Science.gov (United States)

    Pan, Animesh; Biswas, Tapas; Rakshit, Animesh K; Moulik, Satya P

    2015-12-31

    A short account of the developments and perspectives of IKR (iso-kinetic relation) and EEC (enthalpy (H) - entropy (S) compensation) has been presented. The IKR and EEC are known to be extra thermodynamic or empirical correlations though linear H-S correlation can be thermodynamically deduced. Attempt has also been made to explain the phenomena in terms of statistical thermodynamics. In this study, we have briefly revisited the fundamentals of both IKR and EEC from kinetic and thermodynamic grounds. A detailed revisit of the EEC phenomenon on varied kinetic and equilibrium processes has been also presented. Possible correlations among the free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) changes of different similar and nonsimilar chemical processes under varied conditions have been discussed with possible future projections.

  18. The significance test controversy revisited the fiducial Bayesian alternative

    CERN Document Server

    Lecoutre, Bruno

    2014-01-01

    The purpose of this book is not only to revisit the “significance test controversy,”but also to provide a conceptually sounder alternative. As such, it presents a Bayesian framework for a new approach to analyzing and interpreting experimental data. It also prepares students and researchers for reporting on experimental results. Normative aspects: The main views of statistical tests are revisited and the philosophies of Fisher, Neyman-Pearson and Jeffrey are discussed in detail. Descriptive aspects: The misuses of Null Hypothesis Significance Tests are reconsidered in light of Jeffreys’ Bayesian conceptions concerning the role of statistical inference in experimental investigations. Prescriptive aspects: The current effect size and confidence interval reporting practices are presented and seriously questioned. Methodological aspects are carefully discussed and fiducial Bayesian methods are proposed as a more suitable alternative for reporting on experimental results. In closing, basic routine procedures...

  19. Fermentation of barley flour with Lactobacillus reuteri

    OpenAIRE

    Pallin, Anton

    2015-01-01

    Fermentation of foodstuffs has beneficial effects on shelf life, taste and texture and possibly also health of the consumer. Products containing microbes with beneficial health effects for the host are defined as probiotics. One probiotic bacterium, Lactobacillus reuteri, has been shown to exert positive effects on a number of diseases and disorders, including a possible protective role against increased intestinal permeability or ‘leaky gut’. Increased intestinal permeability ...

  20. Quality of fermented whey beverage with milk

    OpenAIRE

    Rakin Marica B.; Bulatović Maja Lj.; Zarić Danica B.; Stamenković-Đoković Marijana M.; Krunić Tanja Ž.; Borić Milka M.; Vukašinović-Sekulić Maja S.

    2016-01-01

    One of the most economical ways of whey processing is the production of beverages, that represents a single process that exploits all the potential of whey as a raw material. Functional and sensory characteristics of whey based beverages are a criterion that is crucial to the marketing of products and win over consumers. The aim of this study was to determine nutritional and functional characteristics of fermented whey beverage with milk and commercial ABY-...

  1. Fermentation based carbon nanotube multifunctional bionic composites

    OpenAIRE

    Luca Valentini; Silvia Bittolo Bon; Stefano Signetti; Manoj Tripathi; Erica Iacob; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extr...

  2. Food fermentations: Microorganisms with technological beneficial use

    DEFF Research Database (Denmark)

    Bourdichon, François; Casaregola, Serge; Farrokh, Choreh;

    2012-01-01

    Microbial food cultures have directly or indirectly come under various regulatory frameworks in the course of the last decades. Several of those regulatory frameworks put emphasis on “the history of use”, “traditional food”, or “general recognition of safety”. Authoritative lists of microorganism......, legumes, cereals, beverages, and vinegar). We have also reviewed and updated the taxonomy of the microorganisms used in food fermentations in order to bring the taxonomy in agreement with the current standing in nomenclature....

  3. Discussion of "Computational Electrocardiography: Revisiting Holter ECG Monitoring".

    Science.gov (United States)

    Baumgartner, Christian; Caiani, Enrico G; Dickhaus, Hartmut; Kulikowski, Casimir A; Schiecke, Karin; van Bemmel, Jan H; Witte, Herbert

    2016-08-01

    This article is part of a For-Discussion-Section of Methods of Information in Medicine about the paper "Computational Electrocardiography: Revisiting Holter ECG Monitoring" written by Thomas M. Deserno and Nikolaus Marx. It is introduced by an editorial. This article contains the combined commentaries invited to independently comment on the paper of Deserno and Marx. In subsequent issues the discussion can continue through letters to the editor.

  4. Revisiting the Panko-Halverson Taxonomy of Spreadsheet Errors

    OpenAIRE

    Panko, Raymond R.

    2008-01-01

    The purpose of this paper is to revisit the Panko-Halverson taxonomy of spreadsheet errors and suggest revisions. There are several reasons for doing so: First, the taxonomy has been widely used. Therefore, it should have scrutiny; Second, the taxonomy has not been widely available in its original form and most users refer to secondary sources. Consequently, they often equate the taxonomy with the simplified extracts used in particular experiments or field studies; Third, perhaps as a consequ...

  5. China in 2005 Revisited: The Implications of International Capital Mobility

    OpenAIRE

    Ianchovichina, Elena; McDougall, Robert; Hertel, Thomas

    2000-01-01

    This paper revisits the analysis of the implications of China's economic growth on her trading partners presented in Arndt et al. (1997) using a dynamic, applied general equilibrium model that features international capital mobility. We find that accounting for the impact of China's growth on international capital markets reverses some of the findings in the paper by Arndt et al. In particular, net creditor regions lose while net debtor regions benefit from an economic slowdown in China du...

  6. Audit probability versus effectiveness: The Beckerian approach revisited

    OpenAIRE

    Rablen, M

    2014-01-01

    This is the accepted version of the following article: RABLEN, M. D. (2014), Audit Probability versus Effectiveness: The Beckerian Approach Revisited. Journal of Public Economic Theory, 16: 322–342, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/jpet.12062/abstract. The Beckerian approach to tax compliance examines how a tax authority can maximize social welfare by trading-off audit probability against the fine rate on undeclared tax. This paper offers...

  7. The angular momentum of baryons and dark matter halos revisited

    OpenAIRE

    Kimm, Taysun; Devriendt, Julien; Slyz, Adrianne; Pichon, Christophe; Kassin, Susan A.; Dubois, Yohan

    2011-01-01

    Recent theoretical studies have shown that galaxies at high redshift are fed by cold, dense gas filaments, suggesting angular momentum transport by gas differs from that by dark matter. Revisiting this issue using high-resolution cosmological hydrodynamics simulations with adaptive mesh refinement, we find that at the time of accretion, gas and dark matter do carry a similar amount of specific angular momentum, but that it is systematically higher than that of the dark matter halo as a whole....

  8. Trade and civil conflict : revisiting the cross-country evidence

    OpenAIRE

    Cali, Massimiliano; Mulabdic, Alen

    2014-01-01

    This paper revisits and expands the evidence on the impact of trade shocks on intra-state conflict with a large sample of developing countries in the 1960-2010 period. The results suggest that increases in the prices of a country's exported commodities raise the country's risk of civil conflict and its duration. The effect on conflict risk is mainly driven by the price of point-source comm...

  9. Simulation of Two-Way Pushdown Automata Revisited

    OpenAIRE

    Robert Glück

    2013-01-01

    The linear-time simulation of 2-way deterministic pushdown automata (2DPDA) by the Cook and Jones constructions is revisited. Following the semantics-based approach by Jones, an interpreter is given which, when extended with random-access memory, performs a linear-time simulation of 2DPDA. The recursive interpreter works without the dump list of the original constructions, which makes Cook's insight into linear-time simulation of exponential-time automata more intuitive and the complexity arg...

  10. Probit Model Estimation Revisited: Trinomial Models of Household Car Ownership

    OpenAIRE

    Bunch, David S; Kitamura, Ryuichi

    1991-01-01

    In this paper we revisit various important issues relating to practical estimation of the multinomial probit model, using an empirical analysis of car ownership as a test case. To provide context, a brief literature review of empirical probit studies is included. Estimates are obtained for a full range of model specifications, including models with random (uncorrelated and correlated) taste variation and/or a general random error structure, and issues of estimability, specification testing, a...

  11. Power Market Design beyond 2020: Time to Revisit Key Elements?

    OpenAIRE

    Neuhoff, Karsten; Ruester, Sophia; Schwenen, Sebastian

    2015-01-01

    We revisit key elements of European power market design with respect to both short term operation and longer-term investment and re-investment choices. For short term markets, the European policy debate focuses on the definition of common interfaces, like for example gate closure time. We argue that that this is insufficient if the market design is to accommodate for the different needs of renewable and conventional generation assets and different flexibility options. The market design needs ...

  12. New Families in the Stable Homotopy of Spheres Revisited

    Institute of Scientific and Technical Information of China (English)

    LIN Jin Kun

    2002-01-01

    This paper constructs a new family in the stable homotopy of spheres πt-6S representedby hngoγ3 ∈ E26,t in the Adams spectral sequence which revisits the bn-1g0γ3-elements ∈πt-7S con-structed in [3], where t = 2pn(p- 1) +6(p2 + p+ 1)(p- 1) and p ≥ 7 is a prime, n ≥ 4.

  13. Revisiting Barriers to Trade: Do Foregone Health Benefits Matter?

    OpenAIRE

    Zhang, Sidi; Kerr, William A.

    2009-01-01

    This paper examins the question of revisiting the imposition of existing trade barriers in one case of an evolving marketplace – when a traditional food product is altered to provide, or discovered to have, human health benefits that increases their value to consumers. In other words, the food becomes a functional food. A functional food has the potential provide direct benefits to consumers as well as indirect benefits to society in the form of health care cost savings. If the trade barrier ...

  14. The Dutch Disease revisited: absorption constraint and learning by doing

    OpenAIRE

    Iacono, Roberto

    2014-01-01

    This paper revisits the Dutch disease by analyzing the general equilibrium effects of a resource shock on a dependent economy, both in a static and dynamic setting. The novel aspect of this study is to incorporate two features of the Dutch disease literature that have only been analyzed in isolation from each other: capital accumulation with absorption constraint and productivity growth induced by learning by doing. The conventional result of long-run exchange rate appreciation is maintained ...

  15. Clausius/Cosserat/Maxwell/Weyl Equations: The Virial Theorem Revisited

    OpenAIRE

    Pommaret, Jean-François

    2015-01-01

    This paper must be published under the title " FROM THERMODYNAMICS TO GAUGE THEORY: THE VIRIAL THEOREM REVISITED " as a chapter of a forthcoming book " GAUGE THEORY AND DIFFERENTIAL GEOMETRY " published by Nova Editors. In 1870, R. Clausius found the virial theorem which amounts to introduce the trace of the stress tensor when studying the foundations of thermodynamics, as a way to relate the absolute temperature of an ideal gas to the mean kinetic energy of its molecules. In 1901, H. Poin...

  16. Radiative Corrections to Neutrino Deep Inelastic Scattering Revisited

    CERN Document Server

    Arbuzov, A B; Kalinovskaya, L V

    2005-01-01

    Radiative corrections to neutrino deep inelastic scattering are revisited. One-loop electroweak corrections are re-calculated within the automatic SANC system. Terms with mass singularities are treated including higher order leading logarithmic corrections. Scheme dependence of corrections due to weak interactions is investigated. The results are implemented into the data analysis of the NOMAD experiment. The present theoretical accuracy in description of the process is discussed.

  17. Revisiting the Response Mechanism of Polymeric Membrane Based Heparin Electrodes

    OpenAIRE

    Bell, Andrea K.; Höfler, Lajos; Meyerhoff, Mark E.

    2011-01-01

    Potentiometric membrane electrodes that respond to heparin and other polyanions were introduced in the early 1990s. Herein, the mechanism of polymer membrane electrode type heparin sensors is revisited. The extraction/diffusion of heparin is studied via both potentiometric and impedance spectroscopic techniques using a pre-fractionated heparin preparation that contains polyanionic species > 10000 Daltons. The reversal in EMF response using this heparin preparation indicates diffusion of highe...

  18. [The antihypertensive effect of fermented milks].

    Science.gov (United States)

    Domínguez González, Karina N; Cruz Guerrero, Alma E; Márquez, Humberto González; Gómez Ruiz, Lorena C; García-Garibay, Mariano; Rodríguez Serrano, Gabriela M

    2014-01-01

    There is a great variety of fermented milks containing lactic acid bacteria that present health-promoting properties. Milk proteins are hydrolyzed by the proteolytic system of these microorganisms producing peptides which may also perform other functions in vivo. These peptides are encrypted within the primary structure of proteins and can be released through food processing, either by milk fermentation or enzymatic hydrolysis during gastrointestinal transit. They perform different activities, since they act in the cardiovascular, digestive, endocrine, immune and nervous systems. Bioactive peptides that have an antihypertensive, antithrombotic, antioxidant and hypocholesterolemic effect on the cardiovascular system can reduce the risk factors for chronic disease manifestation and help improve human health. Most studied bioactive peptides are those which exert an antihypertensive effect by inhibiting the angiotensin-converting enzyme (ACE). Recently, the study of these peptides has focused on the implementation of tests to prove that they have an effect on health. This paper focuses on the production of ACEinhibitory antihypertensive peptides from fermented milks, its history, production and in vivo tests on rats and humans, on which its hypotensive effect has been shown. PMID:24721277

  19. Fermentation based carbon nanotube multifunctional bionic composites

    Science.gov (United States)

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-06-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal.

  20. Optimization of Fermentation Condition of Yeast Culture

    Institute of Scientific and Technical Information of China (English)

    WANG Qiuju; XU Li; CUI Yizhe

    2008-01-01

    Culture condition of every phase for fermentation of yeast culture was studied, and its solid and liquid conditions of elaboration were optimized to improve the total counts of living cells.Results showed that microzyme grew best at 30℃ when solid fermented,and the count of the living cells reached the tiptop with pH 5.5.The count of Candida tropicalis could reach 137.96×109 cfu·g-1,the count of Saccharomyces cerevisia could reach 134.62×109 cfu·g-1;the best liquid fermentation condition for cell-wall broken was 50℃ for 28 h,the rate of cell-wall broken could reach 80% at least;the rate of vitamin loss in yeast could be the minimun, the loss rate of vitamin B1 in Candida tropicalis and Saccharomyces cerevisiae was 8.71% and 19.54% respectively, the loss rate of vitamin B2 was 19.39% and 13.18%,respectively,and the loss rate of vitamin B6 was 6.3% and 3.04%,respectively.

  1. Fermentation based carbon nanotube multifunctional bionic composites

    Science.gov (United States)

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal. PMID:27279425

  2. Utilization of cassava waste through fermentation technology

    International Nuclear Information System (INIS)

    Over 400 isolates of molds were screened for raw starch digesting enzymes and aspergillus J8 ad Rhizopus N37 were selected for further investigations. Crude enzymes obtained from wheat bran was higher than from rice bran. Crude enzymes from Aspergillus is active at pH 4.0, whereas that from Rhizopus is active at pH 5.0. Aspergillus J8 gave higher yield of silage fermentation. Selection of yeast strain was accomplished, it was found that Saccharomyces cerevisiae SC90, the local commercial strain (non-flocculent) performed best in fermentation of cassava mash. Another strain AM12, a flocculent fusant strain derived from fusion between flocculent strain and sake brewing strain was comparable to that of commercial strain at normal temperature but performed better at higher temperature up to 40 deg C. It is unlikely that fuel alcohol produced from raw cassava will be able to compete with petroleum fuel at this moment. However, silage fermentation to increase nutritional quality of the silage through selected strains of microorganisms has a good prospect to pursue. (author)

  3. Kinetics of saccharose fermentation by Kombucha

    Directory of Open Access Journals (Sweden)

    Lončar Eva S.

    2014-01-01

    Full Text Available Kinetics of saccharose fermentation by Kombucha is not yet well defined due to lack of knowledge of reaction mechanisms taking place during this process. In this research kinetics of saccharose fermentation by Kombucha was analysed using the suggested empirical model. The data were obtained on 1.5 g L-1 of black tea, with 66.47 g L-1 of saccharose and using 10% (v/v or 15% (v/v of Kombucha. Total number of viable cells was as follows: approximately 5x105 of yeast cells per mL of the inoculum and approximately 2x106 of bacteria cells per mL of the inoculum. The samples were analysed after 0, 3, 4, 5, 6, 7 and 10 days. Their pH values and contents of saccharose, glucose, fructose, total acids and ethanol were determined. A saccharose concentration model was defined as sigmoidal function at 22oC and 30oC, and with 10% (v/v and 15% (v/v of inoculum quantity. Determination coefficients of the functions were very high (R2>0.99. Reaction rates were calculated as first derivatives of Boltzmann’s functions. No simple correlation between rate of reaction and independent variables (temperature and inoculum concentration was found. Analysis of empirical model indicated that saccharose fermentation by Kombucha occurred according to very complex kinetics. [Projekat Ministarstva nauke Republike Srbije, br. III 46009

  4. Mathematical model of sugar uptake in fermenting yeasted dough.

    Science.gov (United States)

    Loveday, S M; Winger, R J

    2007-07-25

    Fermentation prior to freezing significantly reduces the shelf life of frozen dough, measured as a decline in proofing power. Changes during fermentation caused by yeast metabolism have previously been described empirically on a dough weight basis and have not been mathematically modeled. In this work, yeast metabolites were quantified in fermenting dough and their concentrations were estimated in the aqueous environment around yeast cells. The osmotic pressure in the aqueous phase increases by 23% during 3 h of fermentation, which depresses the freezing point by 1 degrees C. The rise in osmotic pressure and the accumulation of ethanol may affect phase equilibria in the dough, baking properties, and the shelf life of frozen dough. Predictive modeling equations fitted sugar concentration data accurately. It was found that the preference of baker's yeast for glucose over fructose was stronger in fermenting dough than in liquid fermentations. The usefulness of the model in industrial bakery formulation work was demonstrated. PMID:17595109

  5. Characterization of the microbial diversity in yacon spontaneous fermentation

    OpenAIRE

    Reina, L. D.; Pérez-Díaz, I. M.; Breidt, F.; Azcarate-Peril, M. A.; E.Medina; Butz, N.V.

    2015-01-01

    The prebiotic fructooligosaccharides (FOS) content of yacon makes this root an attractive alternative for the supplementation of a variety of food products. The preservation of yacon by fermentation has been proposed as an alternative to increase the probiotic content of the root concomitantly with its shelf life. Thus the fermented yacon could have significant functional content. The objective of this research was to characterize the biochemistry and microbiology of spontaneous yacon ferment...

  6. 27 CFR 25.55 - Formulas for fermented products.

    Science.gov (United States)

    2010-04-01

    ... production of a fermented beverage designated as “beer,” “ale,” “porter,” “stout,” “lager,” or “malt liquor... the production of one or more other fermented products. The beer base must conform to the standards... recognized as a traditional ingredient in the production of a fermented beverage designated as “beer,”...

  7. Does fermented milk possess antihypertensive effect in humans?

    DEFF Research Database (Denmark)

    Usinger, Lotte; Ibsen, Hans; Jensen, Lars T

    2009-01-01

    The putative antihypertensive effect of milk after fermentation by lactic bacteria has attracted attention over the past 20 years. Research on fermented milk and hypertension has mainly focused on the content of peptides with in-vitro angiotensin converting enzyme-inhibitor effect. However......, fermented milk products contain several proteins, peptides and minerals, all with possible different antihypertensive modes of actions. The burden of cardiovascular events in industrialized countries caused by hypertension is considerable. Diet modifications are one way to lower blood pressure...

  8. Generalized Net Model of Brevibacterium flavul 22LD Fermentation Process

    OpenAIRE

    Olympia Roeva; Tania Pencheva

    2005-01-01

    In order to render the specific peculiarities of the fermentation processes, as well as to avoid the complexity of mathematical description with systems of differential equations, the elaboration of some new methods and approaches for their modelling and control is predetermined. As a new, alternative approach for modelling of fermentation processes, an application of generalized nets is presented in this paper. The theory of generalized nets is applied to the fermentation process of Brevibac...

  9. Fermented cassava waste and its utilization in broiler chickens rations

    OpenAIRE

    Supriyati,

    2003-01-01

    Cassava waste is a by-product of cassava flour industry and its amount is increasing following the increasing of cassava flour industry. Its utilization as a feedstuff, is limited by its low protein content. The cassava waste is only utilized as the energy source. One of the alternative technology in improving the utilization of cassava waste as a feedstuff, by improving the nutritive value through fermentation process. Fermentation was carried out by solid substrate fermentation using Asperg...

  10. Biotechnology of olive fermentation of ‘Galega' Portuguese variety

    OpenAIRE

    Oliveira, Manuela; Brito, Dulce; Catulo, Luís; Leitão, Fausto; Gomes, Lucília; Silva, Sandra; Vilas-Boas, Luís; Peito, Amália; Fernandes, Isabel; Gordo, Francisca; Peres, Cidália

    2004-01-01

    ‘Galega' is the main Portuguese olive variety providing the greatest percentage of table olive production from homemade and industrial methods. In this work a better understanding of the fermentation involved in both methods is intended. Yeasts and lactic acid bacteria (LAB) constitute the microflora acting in olive fermentation, with Pichia membranaefaciens being the dominant yeast specie present throughout the process. LAB develop their activity mainly along the second fermentation stage ...

  11. Traditional fermented food and beverages for improved livelihoods

    OpenAIRE

    Mejia, Danilo; Marshall, Elaine

    2015-01-01

    "This booklet is intended to heighten awareness about the potential of fermented foods and beverages as a viable enterprise that can contribute to small-scale farmers' income, building on, and in full respect of, important social and cultural factors. It also looks at how fermented food and beverages contribute to food security through preservation and improved nutritional quality. It highlights the opportunities and challenges associated with small-scale fermentation activities, as well as m...

  12. Intracellular ethanol accumulation in Saccharomyces cerevisiae during fermentation.

    OpenAIRE

    D'Amore, T; C.J. Panchal; Stewart, G G

    1988-01-01

    An intracellular accumulation of ethanol in Saccharomyces cerevisiae was observed during the early stages of fermentation (3 h). However, after 12 h of fermentation, the intracellular and extracellular ethanol concentrations were similar. Increasing the osmotic pressure of the medium caused an increase in the ratio of intracellular to extracellular ethanol concentrations at 3 h of fermentation. As in the previous case, the intracellular and extracellular ethanol concentrations were similar af...

  13. Raestur fiskur : air-dried fermented fish the Faroese way

    OpenAIRE

    Svanberg, Ingvar

    2015-01-01

    Background: Fish has played an important role in the diet of the population of the mid-Atlantic Faroe Islands. Dried and fermented fish in particular have been an essential storable protein source in an economy where weather conditions and seasonal fluctuations affect the availability of food. For generations the islanders have prepared raestur fiskur, a home-made air-dried and fermented fish dish made of Atlantic cod (Gadus morhua L.) or saithe (Pollachius virens (L.)). Fermenting the fish i...

  14. Shuidouchi (Fermented Soybean) Fermented in Different Vessels Attenuates HCl/Ethanol-Induced Gastric Mucosal Injury.

    Science.gov (United States)

    Suo, Huayi; Feng, Xia; Zhu, Kai; Wang, Cun; Zhao, Xin; Kan, Jianquan

    2015-11-02

    Shuidouchi (Natto) is a fermented soy product showing in vivo gastric injury preventive effects. The treatment effects of Shuidouchi fermented in different vessels on HCl/ethanol-induced gastric mucosal injury mice through their antioxidant effect was determined. Shuidouchi contained isoflavones (daidzein and genistein), and GVFS (glass vessel fermented Shuidouchi) had the highest isoflavone levels among Shuidouchi samples fermented in different vessels. After treatment with GVFS, the gastric mucosal injury was reduced as compared to the control mice. The gastric secretion volume (0.47 mL) and pH of gastric juice (3.1) of GVFS treated gastric mucosal injury mice were close to those of ranitidine-treated mice and normal mice. Shuidouchi could decrease serum motilin (MTL), gastrin (Gas) level and increase somatostatin (SS), vasoactive intestinal peptide (VIP) level, and GVFS showed the strongest effects. GVFS showed lower IL-6, IL-12, TNF-α and IFN-γ cytokine levels than other vessel fermented Shuidouchi samples, and these levels were higher than those of ranitidine-treated mice and normal mice. GVFS also had higher superoxide dismutase (SOD), nitric oxide (NO) and malonaldehyde (MDA) contents in gastric tissues than other Shuidouchi samples. Shuidouchi could raise IκB-α, EGF, EGFR, nNOS, eNOS, Mn-SOD, Gu/Zn-SOD, CAT mRNA expressions and reduce NF-κB, COX-2, iNOS expressions as compared to the control mice. GVFS showed the best treatment effects for gastric mucosal injuries, suggesting that glass vessels could be used for Shuidouchi fermentation in functional food manufacturing.

  15. Thiosulfate as a metabolic product: the bacterial fermentation of taurine.

    Science.gov (United States)

    Denger, K; Laue, H; Cook, A M

    1997-10-01

    Thiosulfate (S2O32-) is a natural product that is widely utilized in natural ecosystems as an electron sink or as an electron donor. However, the major biological source(s) of this thiosulfate is unknown. We present the first report that taurine (2-aminoethanesulfonate), the major mammalian solute, is subject to fermentation. This bacterial fermentation was found to be catalyzed by a new isolate, strain GKNTAU, a strictly anaerobic, gram-positive, motile rod that formed subterminal spores. Thiosulfate was a quantitative fermentation product. The other fermentation products were ammonia and acetate, and all could be formed by cell-free extracts.

  16. Fermentation to ethanol of pentose-containing spent sulfite liquor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.; Wayman, M.; Parekh, S.K.

    1987-01-01

    Ethanolic fermentation of spent sulfite liquor with ordinary bakers' yeast is incomplete because of this yeast cannot ferment the pentose sugars in the liquor. This results in poor alcohol yields, and a residual effluent problem. By using the yeast Candida shehatae (R) for fermentation of the spent sulfite liquor from a large Canadian alcohol-producing sulfite pulp and paper mill, pentoses as well as hexoses were fermented nearly completely, alcohol yields were raised by 33%, and sugar removal increased by 46%. Inhibitors were removed prior to fermentation by steam stripping. Major benefits were obtained by careful recycling of this yeast, which was shown to be tolerant both of high sugar concentrations and high alcohol concentrations. When sugar concentrations over 250 g/L (glucose:xylose 70:30) were fermented, ethanol became an inhibitor when its concentration reached over 90 g/L. However, when the ethanol was removed by low-temperature vacuum distillation, fermentation continued and resulted in a yield of 0.50 g ethanol/g sugar consumed. Further improvement was achieved by combining enzyme saccharification of sugar oligomers with fermentation. This yeast is able to ferment both hexoses and pentoses simultaneously, efficiently, and rapidly.

  17. Characterization of the microbial diversity in yacon spontaneous fermentation

    Science.gov (United States)

    Reina, L. D.; Pérez-Díaz, I. M.; Breidt, F.; Azcarate-Peril, M. A.; Medina, E.; Butz, N.V.

    2015-01-01

    The prebiotic fructooligosaccharides (FOS) content of yacon makes this root an attractive alternative for the supplementation of a variety of food products. The preservation of yacon by fermentation has been proposed as an alternative to increase the probiotic content of the root concomitantly with its shelf life. Thus the fermented yacon could have significant functional content. The objective of this research was to characterize the biochemistry and microbiology of spontaneous yacon fermentation and define the viability of the proposed process. The biochemical analysis of spontaneous heterolactic fermentation of yacon showed a progressive drop in pH with increased lactic and acetic acids, and the production of mannitol during fermentation. The microbial ecology of yacon fermentation was investigated using culture-dependent and culture-independent methods. Bacterial cell counts revealed a dominance of lactic acid bacteria (LAB) over yeasts, which were also present during fermentation. Results showed that the heterofermentative LAB were primarily Leuconostoc species, which dominated the fermentation. The fermentation of yacon by Leuconostoc spp. is thus presented as a viable method to achieve long term preservation of this root. PMID:25777679

  18. Tow steps biohydrogen production: biomass pretreatment and fermentation

    Science.gov (United States)

    Ma, C.; Yang, H. H.; Guo, L. J.

    2010-03-01

    This paper investigated the pretreatment of cornstalk and integrated dark-photo fermentation for hydrogen production. Five parameters of the pretreatment experiments, including NaOH concentration, temperature, residence time, and dosage of cellulase and xylanase, were optimized through the L25 (5≙5) orthogonal test. The optimal NaOH concentration, temperature, residence time, and dosage of cellulase and xylanase were 0.5wt%, 115 °C, 3 h, 0.08g/g cornstalk, 0.08g/g cornstalk, respectively. Under the optimal conditions, 0.31g glucose/g cornstalk was obtained. The two-step fermentation consisted of dark fermentation and photo fermentation. The pretreated cornstalk was used as the substrate for dark fermentation, with cow dung as the inoculum. Then the effluents of dark fermentation were employed as the substrate for photo fermentation by photosynthetic bacteria. H2 yield of dark fermentation was 116.7 mL/g cornstalk, with H2 concentration of 41%. After photo fermentation, the total H2 yield increased to 294 mL/g cornstalk.

  19. Effect of mixing during fermentation in yogurt manufacturing.

    Science.gov (United States)

    Aguirre-Ezkauriatza, E J; Galarza-González, M G; Uribe-Bujanda, A I; Ríos-Licea, M; López-Pacheco, F; Hernández-Brenes, C M; Alvarez, M M

    2008-12-01

    In traditional yogurt manufacturing, the yogurt is not agitated during fermentation. However, stirring could be beneficial, particularly for improving heat and mass transport across the fermentation tank. In this contribution, we studied the effect of low-speed agitation during fermentation on process time, acidity profile, and microbial dynamics during yogurt fermentation in 2 laboratory-scale fermenters (3 and 5 L) with different heat-transfer characteristics. Lactobacillus bulgaricus and Streptococcus thermophilus were used as fermenting bacteria. Curves of pH, lactic acid concentration, lactose concentration, and bacterial population profiles during fermentation are presented for static and low-agitation conditions during fermentation. At low-inoculum conditions, agitation reduced the processing time by shortening the lag phase. However, mixing did not modify the duration or the shape of the pH profiles during the exponential phase. In fermentors with poor heat-transfer characteristics, important differences in microbial dynamics were observed between the agitated and nonagitated fermentation experiments; that is, agitation significantly increased the observable specific growth rate and the final microbial count of L. bulgaricus. PMID:19038920

  20. A Perspective on PSE in Fermentation Process Development and Operation

    DEFF Research Database (Denmark)

    Gernaey, Krist

    2015-01-01

    Compared to the chemical industry, the use of PSE methods and tools is not as widespread in industrial fermentation processes. This paper gives an overview of some of the main engineering challenges in industrial fermentation processes. Furthermore, a number of mathematical models are highlighted...... as examples of PSE methods and tools that are used in the context of industrial fermentation technology. Finally, it is discussed what could be done to increase the future use of PSE methods and tools within the industrial fermentation technology area....

  1. Microbiological analysis and antibacterial effects of the indigenous fermented Puer tea

    NARCIS (Netherlands)

    Mo, H.Z.; Xu, X.Q.; Yan, M.C.; Yang Zhu, Yang

    2005-01-01

    Microbiological analysis was done on samples from an indigenously fermented tea - Puer. Microbial counting and identification revealed that Aspergillus niger was the dominating microorganism during the fermentation. Antimicrobial activity of fermentation samples showed inhibitory effect on several f

  2. The Design of Automatic Stirring Ripe Tea Fermenter for Puer Tea

    Directory of Open Access Journals (Sweden)

    Wu Xiaoqiang

    2015-02-01

    Full Text Available Traditional ripe tea fermentation is directly stacking puer tea material on the ground of fermentation workshop relying on natural environment to ferment. The way of fermentation, which has poor degree of sanitation, makes fermentation process influenced by environmental change and difficult to ensure product quality and stability. To solve this problem, we design a ripe tea fermenter for puer tea. There is a certain distance between fermenter and the ground and the spindle of fermenter is designed, so as to achieve automatically agitation instead of manually turning process. It can monitor and control temperature and humidity of tea in the fermenter, so that in the fermentation process puer tea will be in a stable environment, improving fermentation process and the quality of temperature fermentation.

  3. Retention of glucosinolates during fermentation of Brassica juncea: a case study on production of sayur asin

    NARCIS (Netherlands)

    Nugrahedi, P.Y.; Widianarko, B.; Dekker, M.; Verkerk, R.; Oliviero, T.

    2015-01-01

    Fermentation can reduce the concentration of health-promoting glucosinolates in Brassica vegetables. The endogenous enzyme myrosinase is hypothesised to mainly responsible for the degradation of glucosinolates during fermentation. In order to retain glucosinolates in the final fermented product, the

  4. Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Final report, February 1, 1978-January 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    This is a coordinated program to effect the microbiological degradation of cellulosic biomasses and will focus on the use of anaerobic microorganisms which possess cellulolytic enzyme. The studies will attempt to increase the enzyme levels through genetics, mutation and strain selection. In addition, the direct conversion from cellulosic biomasses to liquid fuel (ethanol) and/or soluble sugars by the cellulolytic, anaerobic organism is also within the scope of this program. Process and engineering scale-up, along with economic analyses, will be performed throughout the course of the program. The second area of our major effort is devoted to the production of chemical feedstocks. In particular, three fermentations have been identified for exploration. These are: acrylic acid, acetone/butanol and acetic acid. The main efforts in these fermentations will address means for the reduction of the cost of manufacturing for these large volume chemicals.

  5. Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Progress report, September 1-November 30, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.I.; Cooney, C.L.; Demain, A.L.; Gomez, R.F.; Sinskey, A.J.

    1978-11-01

    Studies on the accumulation of glucose during the fermentation of cellulose by Clostridium thermocellum are discussed. Production of ethanol and its relationship to growth rate in C. thermocellum is reported. Different biomasses were tested for ethanol yields. These included exploded poplar, sugar cane, bagasse, corn cobs, sweet gum, rice straw, and wheat straw. Thermophilic bacteria were tested to determine relationship of temperature to yield of ethanol. A preliminary report on isolating plaque forming emits derived from C. thermocellum is presented as well as the utilization of carbohydrates in nutrition. A cellulose enzyme is being purified from C. thermocellum. The production of chemical feedstocks by fermentation is reported. Acrylic acid, acetone/butanol, and acetic acid, produced by C. propionicum, C. acetobutylicum, and C. thermoaceticum, are discussed. (DC)

  6. Fermentation--a traditional anti-diarrhoeal practice lost? The use of fermented foods in urban and rural Kenya.

    Science.gov (United States)

    Watson, F E; Ngesa, A; Onyang'o, J; Alnwick, D; Tomkins, A M

    1996-03-01

    Whereas modern dietary advice emphasizes the importance of freshly preparing food, many African communities leave food to ferment. Fermentation of cereals is a traditional method of reducing the microbial contamination of porridges. Beliefs and consumption patterns of fermented food were examined among mothers of children aged under five and health workers in a rural and urban community in Kenya. The majority (83%) of rural mothers reported that their families regularly consumed fermented food and over half (66%) gave their young children fermented food. In the urban area, fewer mothers (56%) reported that their families ate fermented food and only (40%) gave their children some kind of fermented food. Several reasons for the declining uses of fermented food were given including education by health workers that fermented foods were bad, declining production and availability, and substitution of traditional foods by commercial products such as soft drinks. Health educators need to consider that mothers may be missing out on a potentially useful means of preventing diarrhoea in their children.

  7. Fermentation instead of animal feeding; In den Fermenter statt in den Magen des Schweins

    Energy Technology Data Exchange (ETDEWEB)

    Brombach, T.

    2008-07-01

    Since 2006, Germany has prohibited the feeding of class K3 waste food from gastronomy, canteens and the food industry to pigs. Fermentation is a creative solution. In Haid on the Schwaebische Alb mountain range, two creative waste managers developed a plant for power generation from fat and used oils. (orig.)

  8. La fermentation éthanolique. Les microorganismes Ethanol Fermentation. The Microorganisms

    Directory of Open Access Journals (Sweden)

    Ballerini D.

    2006-11-01

    Full Text Available Cette étude précise l'état actuel des connaissances concernant la fermentation éthanolique, d'un point de vue microbiologique. Outre les microorganismes utilisés depuis longtemps, sont décrites les nouvelles espèces de levures et de bactéries capables de transformer en éthanol des substrats aussi divers que les composés cellulosiques et hémicellulosiques issus de la biomasse et leurs produits d'hydrolyse. Pour la fermentation des substrats traditionnels tels que les mélasses et les jus d'extraction de plantes sucrières, ou encore l'amidon de maïs, les performances des levures du genre Saccharomyces sont comparées à celles des bactéries du genre Zymomonas. This review gives the state-of-the-art of what is known about ethanol fermentation from the microbiological viewpoint. In addition to the microorganisms that have been used for a long time, it describes new species of yeasts and bacteria capable of transforming, in ethanol, substrates including such different ones as cellulosic and hemicellulosic compounds issuing from biomass and their hydrolysis products. For the fermentation of traditional substrates such as molasses and juices extracted from sugar plants, or cornstarch, the performances of yeasts of the Saccharomyces type are compared to those of bacteria of the Zymomonas type.

  9. Fermentation performance of engineered and evolved xylose-fermenting Saccharomyces cerevisiae strains

    DEFF Research Database (Denmark)

    Sonderegger, M.; Jeppsson, M.; Larsson, C.;

    2004-01-01

    Lignocellulose hydrolysate is an abundant substrate for bioethanol production. The ideal microorganism for such a fermentation process should combine rapid and efficient conversion of the available carbon sources to ethanol with high tolerance to ethanol and to inhibitory components in the hydrol...

  10. Biologically active amines in fermented and non-fermented commercial soybean products from the Spanish market.

    Science.gov (United States)

    Toro-Funes, N; Bosch-Fuste, J; Latorre-Moratalla, M L; Veciana-Nogués, M T; Vidal-Carou, M C

    2015-04-15

    Biologically active amines were determined in commercial soybean products. The antioxidant polyamines were found in both non-fermented and fermented soybean products. Natto and tempeh showed the highest content of polyamines (75-124 and 11-24 mg/kg of spermidine and spermine, respectively). On the other hand, the bacterial-related biogenic amines, tyramine, histamine, tryptamine and β-phenylethylamine, were detected in practically all fermented products with a high variability. The highest contents were found in sufu, tamari and soybean paste. Extremely high tyramine and histamine contents, 1700 and 700 mg/kg, respectively, found in some sufu samples could be unhealthy. However, biogenic amines observed in the other soybean products should not be a risk for healthy consumers. However, individuals who take monoamine and diamine oxidase inhibitors drugs should be strongly recommended to avoid this kind of products in order to suffer no adverse health effects. These biogenic amines were not detected in non-fermented soybean products.

  11. Fermentation of melon seeds for “Ogiri egusi” as affected by fermentation variables using Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Ogueke, C. C.

    2013-12-01

    Full Text Available Aims: Manipulation of fermentation variables during ‘Ogiri egusi’ production using Bacillus subtilis was studied with the view to improving the fermentation process and quality of product. The variables studied were relative humidity (RH, temperature and pore size of wrapping material. Methodology and results: Effect of variables on amino nitrogen, pH and peroxide value was determined on 24 h basis for 96 h. Attempt on optimization of process using response surface method was made. Amino nitrogen increased with fermentation time, the highest value (6.25 mg N/g being obtained from sample fermented at 75% RH, temperature 35 °C and 90 µm pore size of wrapping material. Fermentation attained its peak at 48 h fermentation time. pH increased into the alkaline range within the period, the highest value (7.81 being from sample that gave the highest amount of amino nitrogen. Peroxide values obtained in all samples were far below the recommended value of 30 Meq/kg. However, the highest value (4.16 Keq/kg was obtained in sample fermented at 85% RH, temperature 30 °C and 70 µm pore size of wrapper. Statistical analysis and response surface plots associated with analysis showed that the quadratic effect of variables was significant (p = 0.05. Effects of relative humidity and pore size of wrapping material were also significant and accounted for 99.56% of the amino nitrogen variation. Conclusion, significance and impact study: Manipulation of the fermentation variables significantly improved the process. Thus use of response surface method optimized the fermentation process especially the effects of relative humidity and pore size of wrapping materials. The suggested combination of variables for optimum fermentation is 75% RH, temperature 35 °C and 70 µm pore size of wrapper. This ultimately will improve product quality and reduce fermentation time.

  12. CITRIC ACID PRODUCTION USING FERMENTATION TECHNOLOGY

    OpenAIRE

    ANKIT KUMAR; OM PRAKASH VERMA

    2007-01-01

    Citric acid, C3H4OH(COOH)3, (Scheele and Wehmer 1897) can be generally manufactured by chemical synthesis which is not much preferred now-a-days because of high costs involved in it and also by fermentation of sugar containing sources in the presence of fungus Aspergillus niger. Citric acid is used in confections and soft drinks ( as a flavouring agent), in metal-cleaning compositions, and in improving the stability of foods and other organic substances by suppressing the deleterious action o...

  13. Effect of fermentation and drying on cocoa polyphenols.

    Science.gov (United States)

    Albertini, Barbara; Schoubben, Aurélie; Guarnaccia, Davide; Pinelli, Filippo; Della Vecchia, Mirco; Ricci, Maurizio; Di Renzo, Gian Carlo; Blasi, Paolo

    2015-11-18

    Cocoa seed polyphenols have demonstrated interesting beneficial effects in humans. Most polyphenols contained in fresh seeds are chemically modified during fermentation, drying, and cocoa powder or chocolate production. The improvement of these procedures to obtain a high-polyphenol-content cocoa is highly desirable. To this aim, a field investigation on the effect of fermentation and natural drying on fine flavor National cocoa (cacao Nacional) was performed. Cocoa seeds were fermented for 6 days and, every day, samples were sun-dried and analyzed for polyphenol content and antioxidant power. During the first 2 days of fermentation, Folin-Ciocalteu and FRAP tests evidenced a significant reduction of polyphenol content and antioxidant capacity, respectively. Changes during the following days of fermentation were less significant. Epicatechin, the most studied member of the catechin family, followed a similar pathway of degradation. Data confirmed the high impact of fermentation and drying on cocoa seed polyphenols. Fermentation and drying are, on the one hand, necessary to obtain cocoa flavor and palatability but, on the other hand, are responsible for greatly compromising polyphenol content. To obtain high-polyphenol-content cocoa, the existing fermentation, drying, and manufacturing protocols should be scientifically reviewed to understand and modify the critical steps.

  14. Effects of lactic acid bacteria contamination on lignocellulosic ethanol fermentation

    Science.gov (United States)

    Slower fermentation rates, mixed sugar compositions, and lower sugar concentrations may make lignocellulosic fermentations more susceptible to contamination by lactic acid bacteria (LAB), which is a common and costly problem to the corn-based fuel ethanol industry. To examine the effects of LAB con...

  15. Quality, safety, biofunctionality and fermentation control in soya

    NARCIS (Netherlands)

    Nout, M.J.R.

    2015-01-01

    Fermented soya foods play an important role in the diet and health of a large part of the world population. We will discuss the manufacture and properties of: soya sauce; semi-solid pastes such as miso, doujiang and doenjang; and solid fermented soya foods such as natto, kinema, tempe, sufu and douc

  16. Effects of fermented soya bean on digestion, absorption and diarrhoea

    NARCIS (Netherlands)

    Kiers, J.L.

    2001-01-01

    For many centuries Asian people have consumed soya beans in various forms of traditional fermented soya bean foods. Major desirable aspects of fermented soya bean foods are their attractive flavour and texture, certain nutritional properties, and possible health promoting effects. This study describ

  17. Influence of sodium chloride on wine yeast fermentation performance

    Directory of Open Access Journals (Sweden)

    Stilianos Logothetis

    2010-06-01

    Full Text Available Stilianos Logothetis1, Elias T Nerantzis2, Anna Gioulioti3, Tasos Kanelis2, Tataridis Panagiotis2, Graeme Walker11University of Abertay Dundee, School of Contemporary Sciences, Dundee, Scotland; 2TEI of Athens Department of Oenology and Spirit Technology, Biotechnology and Industrial Fermentations Lab Agiou Spiridonos, Athens, Greece; 3Ampeloiniki SA Industrial Park Thermi, Thessaloniki, GreeceAbstract: This paper concerns research into the influence of salt (sodium chloride on growth, viability and fermentation performance in a winemaking strain of the yeast, Saccharomyces cerevisiae. Experimental fermentations were conducted in both laboratory-scale and industrial-scale experiments. Preculturing yeasts in elevated levels of sodium chloride, or salt “preconditioning” led to improved fermentation performance. This was manifest by preconditioned yeasts having an improved capability to ferment high-sugar containing media with increased cell viability and with elevated levels of produced ethanol. Salt-preconditioning most likely influenced the stress-tolerance of yeasts by inducing the synthesis of key metabolites such as trehalose and glycerol. These compounds may act to improve cells’ ability to withstand osmostress and ethanol toxicity during fermentations of grape must. Industrial-scale trials using salt-preconditioned yeasts verified the benefit of this novel physiological cell engineering approach to practical winemaking fermentations.Keywords: salt, preconditioning, fermentation performance, Saccharomyces cerevisiae, wine

  18. 21 CFR 573.450 - Fermented ammoniated condensed whey.

    Science.gov (United States)

    2010-04-01

    ... use of fermented ammoniated condensed whey and equivalent crude protein from all other added forms of... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Fermented ammoniated condensed whey. 573.450 Section 573.450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...

  19. Microbiological safety of kinema: a fermented soya bean food.

    NARCIS (Netherlands)

    Nout, M.J.R.; Bakshi, D.; Sarkar, P.K.

    1998-01-01

    Kinema is a fermented soya bean food of Nepal and the hilly regions of Northeastern States of India. Generally, the fermentation is dominated by Bacillus spp. that often cause alkalinity and desirable stickiness in the product. The present study was undertaken in a limited number of commercial (mark

  20. Tempe fermentation, innovation and functionality: update into the third millenium

    NARCIS (Netherlands)

    Nout, M.J.R.; Kiers, J.L.

    2005-01-01

    Fermented foods represent on average one-third of total food consumption. Tempe is a major fermented soyabean food and is known for its attractive flavour, texture and superior digestibility. This present review aims at providing an overview of literature data from ca 1990 until present. Although tr

  1. Effect of fermentation and drying on cocoa polyphenols.

    Science.gov (United States)

    Albertini, Barbara; Schoubben, Aurélie; Guarnaccia, Davide; Pinelli, Filippo; Della Vecchia, Mirco; Ricci, Maurizio; Di Renzo, Gian Carlo; Blasi, Paolo

    2015-11-18

    Cocoa seed polyphenols have demonstrated interesting beneficial effects in humans. Most polyphenols contained in fresh seeds are chemically modified during fermentation, drying, and cocoa powder or chocolate production. The improvement of these procedures to obtain a high-polyphenol-content cocoa is highly desirable. To this aim, a field investigation on the effect of fermentation and natural drying on fine flavor National cocoa (cacao Nacional) was performed. Cocoa seeds were fermented for 6 days and, every day, samples were sun-dried and analyzed for polyphenol content and antioxidant power. During the first 2 days of fermentation, Folin-Ciocalteu and FRAP tests evidenced a significant reduction of polyphenol content and antioxidant capacity, respectively. Changes during the following days of fermentation were less significant. Epicatechin, the most studied member of the catechin family, followed a similar pathway of degradation. Data confirmed the high impact of fermentation and drying on cocoa seed polyphenols. Fermentation and drying are, on the one hand, necessary to obtain cocoa flavor and palatability but, on the other hand, are responsible for greatly compromising polyphenol content. To obtain high-polyphenol-content cocoa, the existing fermentation, drying, and manufacturing protocols should be scientifically reviewed to understand and modify the critical steps. PMID:26086521

  2. Integration of fermentation and cooling crystallisation to produce organic acids

    NARCIS (Netherlands)

    Roa Engel, C.A.

    2010-01-01

    Fermentation products are gaining more attention in the last years due to the fact that the metabolic and genetic engineering field has been developing techniques to enhance fermentation yields and make biochemical processes competitive compared to traditional chemical production. However, as fermen

  3. Occurrence and function of yeasts in Asian indigenous fermented foods

    NARCIS (Netherlands)

    Aidoo, K.E.; Nout, M.J.R.; Sarkar, P.K.

    2006-01-01

    In the Asian region, indigenous fermented foods are important in daily life. In many of these foods, yeasts are predominant and functional during the fermentation. The diversity of foods in which yeasts predominate ranges from leavened bread-like products such as nan and idli, to alcoholic beverages

  4. Microbiota of Tayohounta, a fermented baobab flavour food of Benin

    NARCIS (Netherlands)

    Chadare, F.J.; Jonkman, J.; Wolkers-Rooijackers, J.C.M.; Nout, M.J.R.; Hounhouigan, J.D.; Zwietering, M.H.

    2011-01-01

    The present work provides data on the microbial composition of Tayohounta, a product of natural fermentation of baobab seed kernels. Samples were collected from 3 different small scale producers from Benin at the end of the fermentation process. Microorganisms were enumerated and identified using ph

  5. Fermentation and Electrohydrogenic Approaches to Hydrogen Production (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Maness, P. C.; Thammannagowda, S.; Magnusson, L.; Logan, B.

    2010-06-01

    This work describes the development of a waste biomass fermentation process using cellulose-degrading bacteria for hydrogen production. This process is then integrated with an electrohydrogenesis process via the development of a microbial electrolysis cell reactor, during which fermentation waste effluent is further converted to hydrogen to increase the total output of hydrogen from biomass.

  6. Parakari, an indigenous fermented beverage using amylolytic Rhizopus in Guyana.

    Science.gov (United States)

    Henkel, Terry W

    2005-01-01

    The alcoholic beverage parakari is a product of cassava (Manihot esculenta Crantz) fermentation by Amerindians of Guyana. While fermented beverage production is nearly universal among indigenous Amazonians, parakari is unique among New World beverages because it involves the use of an amylolytic mold (Rhizopus sp., Mucoraceae, Zygomycota) followed by a solid substratum ethanol fermentation. The mycological significance of this dual fermentation process previously was unrecognized. A detailed study of parakari fermentation was made in the Wapisiana Amerindian village of Aishalton, South Rupununi, Guyana. Thirty steps were involved in parakari manufacture, and these exhibited a high degree of sophistication, including the use of specific cassava varieties, control of culture temperature and boosting of Rhizopus inoculum potential with purified starch additives. During the fermentation process, changes in glucose content, pH, flavor, odor and culture characteristics were concomitant with a desirable finished product. Parakari is the only known example of an indigenous New World fermentation that uses an amylolytic mold, likely resulting from domestication of a wild Rhizopus species in the distant past. Parakari production is remarkably similar to dual fermentations of Asia, yet it was independently derived.

  7. Extracellular enzyme activities during cassava fermentation for 'fufu' production.

    Science.gov (United States)

    Oyewole, O B; Odunfa, S A

    1992-01-01

    Amylase and pectin methyl esterase activities increased rapidly during the early period of the fermentation of cassava for 'fufu' production, attaining their peak activities after 12 and 24h, respectively. Cellulase activity was lower and approximately constant for most of the fermentation period.

  8. Improvement of dry fractionation ethanol fermentation by partial germ supplementation

    Science.gov (United States)

    Ethanol fermentation of dry fractionated grits (corn endosperm pieces) containing different levels of germ was studied using the dry grind process. Partial removal of germ fraction allows for marketing the germ fraction and potentially more efficient fermentation. Grits obtained from a dry milling p...

  9. Fermentation of Fructooligosaccharides by Lactic Acid Bacteria and Bifidobacteria†

    OpenAIRE

    Kaplan, Handan; Hutkins, Robert W.

    2000-01-01

    Lactic acid bacteria and bifidobacteria were screened of their ability to ferment fructooligosaccharides (FOS) on MRS agar. Of 28 strains of lactic acid bacteria and bifidobacteria examined, 12 of 16 Lactobacillus strains and 7 of 8 Bifidobacterium strains fermented FOS. Only strains that gave a positive reaction by the agar method reached high cell densities in broth containing FOS.

  10. Circular revisit orbits design for responsive mission over a single target

    Science.gov (United States)

    Li, Taibo; Xiang, Junhua; Wang, Zhaokui; Zhang, Yulin

    2016-10-01

    The responsive orbits play a key role in addressing the mission of Operationally Responsive Space (ORS) because of their capabilities. These capabilities are usually focused on supporting specific targets as opposed to providing global coverage. One subtype of responsive orbits is repeat coverage orbit which is nearly circular in most remote sensing applications. This paper deals with a special kind of repeating ground track orbit, referred to as circular revisit orbit. Different from traditional repeat coverage orbits, a satellite on circular revisit orbit can visit a target site at both the ascending and descending stages in one revisit cycle. This typology of trajectory allows a halving of the traditional revisit time and does a favor to get useful information for responsive applications. However the previous reported numerical methods in some references often cost lots of computation or fail to obtain such orbits. To overcome this difficulty, an analytical method to determine the existence conditions of the solutions to revisit orbits is presented in this paper. To this end, the mathematical model of circular revisit orbit is established under the central gravity model and the J2 perturbation. A constraint function of the circular revisit orbit is introduced, and the monotonicity of that function has been studied. The existent conditions and the number of such orbits are naturally worked out. Taking the launch cost into consideration, optimal design model of circular revisit orbit is established to achieve a best orbit which visits a target twice a day in the morning and in the afternoon respectively for several days. The result shows that it is effective to apply circular revisit orbits in responsive application such as reconnoiter of natural disaster.

  11. Fermentability of an enzymatically modified solubilised potato polysaccharide (SPP)

    DEFF Research Database (Denmark)

    Olesen, M.; Gudmand-Høyer, E.; Bergsøe, Merete Norsker;

    1998-01-01

    OBJECTIVE: To study processing and fermentability in the human gastro-intestinal tract of a newly isolated, enzymatically modified, soluble, and highly concentrated (> 80% dietary fibres) solubilised potato fibre (SPP). SETTING: Gastroenterological laboratory. DESIGN, SUBJECTS AND INTERVENTIONS...... was used to evaluate oro-coecal transit time (OCTT) and fermentation. RESULTS: Fermentation of SPP yielded a measurable increase in end-expiratory H2. The total incremental increase in end expiratory H2 due to SPP was unaffected of whether SPP was served alone, as the raw flour served with bread, or baked...... of a meal. CONCLUSIONS: SPP is a fermentable, highly concentrated soluble fibre source. Baking SPP did not interfere with the fermentable properties. Thus, SPP may be interesting as a fibre-supplement in fibre-poor diets. The change in oro-coecal transit time for SPP, depending on the composition...

  12. Sterilization of fermentation vessels by ethanol/water mixtures

    Science.gov (United States)

    Wyman, Charles E.

    1999-02-09

    A method for sterilizing process fermentation vessels with a concentrated alcohol and water mixture integrated in a fuel alcohol or other alcohol production facility. Hot, concentrated alcohol is drawn from a distillation or other purification stage and sprayed into the empty fermentation vessels. This sterilizing alcohol/water mixture should be of a sufficient concentration, preferably higher than 12% alcohol by volume, to be toxic to undesirable microorganisms. Following sterilization, this sterilizing alcohol/water mixture can be recovered back into the same distillation or other purification stage from which it was withdrawn. The process of this invention has its best application in, but is not limited to, batch fermentation processes, wherein the fermentation vessels must be emptied, cleaned, and sterilized following completion of each batch fermentation process.

  13. Sterilization of fermentation vessels by ethanol/water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Wyman, C.E.

    1991-03-20

    This invention is comprised of a method for sterilizing process fermentation vessels with a concentrated alcohol and water mixture integrated in a fuel alcohol or other alcohol production facility. Hot, concentrated alcohol is drawn from a distillation or other purification stage and sprayed into the empty fermentation vessels. This sterilizing alcohol/water mixture should be of a sufficient concentration, preferably higher than 12% alcohol by volume, to be toxic to undesirable microorganisms. Following sterilization, this sterilizing alcohol/water mixture can be recovered back into the same distillation or other purification stage from which it was withdrawn. The process of this invention has its best application in, but is not limited to, batch fermentation processes, wherein the fermentation vessels must be emptied, cleaned, and sterilized following completion of each batch fermentation process.

  14. Fermentation protocols for the nutritive upgrading and detoxification of cassava

    International Nuclear Information System (INIS)

    The paper outlines common recommended procedures to be followed by those working in the area to facilitate the comparison of the results obtained. The report contains the wide spectrum of recommendations towards (i) the methods of preliminary preparation fo the cassava root for further fermentation reprocessing; (ii) optimization of the environmental parameters of the fermentation process, including pretreatment manipulations, moisture content, pH, temperature, aeration, form/size of inoculum, etc., (iii) optimization of the incubation time and selecting the fermentation systems and (iv) the analytical and quality control aspects. Some problems connected with the use of exogenous nitrogen sources to enhance the protein/aminoacid synthesis (supplementation of the fermenting mash with inorganic nitrogen salts, yeast extracts, indigenous sources of vegetable/animal nature, nitrogen fixing bacteria, etc.) are discussed and considered depending on their cost and effectiveness. Concerns about the safety aspects possibly arising from the alteration of the traditional practice of the cassava fermentation are also reported. (author)

  15. Influence of black tea concentrate on kombucha fermentation

    Directory of Open Access Journals (Sweden)

    Malbaša Radomir V.

    2006-01-01

    Full Text Available Kombucha is cultivated on substrates prepared with different concentrations of black tea and substrate obtained by diluting a substrate with highest concentration of black tea with cold tap water. Qualify of produced beverages is compared with the beverage obtained in traditional fermentation of 1.5 g/L of black tea, sweetened with 70 g/L of sucrose. Inoculation was performed with 10% (v/v of fermentation liquid from previous process, and the fermentation was carried out at 28°C under aerobic conditions, for ten days. Process of fermentation was monitored by following pH, total acids. D-gluconic acid and caffeine content. Beverages obtained in fermentation with diluted black tea concentrate had similar amounts of investigated metabolites compared with traditional one. Use of diluted black tea concentrate as a substrate needs the shorter time for the substrate preparation, which significantly saves energy.

  16. A practical method of predicting client revisit intention in a hospital setting.

    Science.gov (United States)

    Lee, Kyun Jick

    2005-01-01

    Data mining (DM) models are an alternative to traditional statistical methods for examining whether higher customer satisfaction leads to higher revisit intention. This study used a total of 906 outpatients' satisfaction data collected from a nationwide survey interviews conducted by professional interviewers on a face-to-face basis in South Korea, 1998. Analyses showed that the relationship between overall satisfaction with hospital services and outpatients' revisit intention, along with word-of-mouth recommendation as intermediate variables, developed into a nonlinear relationship. The five strongest predictors of revisit intention were overall satisfaction, intention to recommend to others, awareness of hospital promotion, satisfaction with physician's kindness, and satisfaction with treatment level. PMID:15923917

  17. Incubation of selected fermentable fibres with feline faecal inoculum: correlations between in vitro fermentation characteristics and end products

    NARCIS (Netherlands)

    Rochus, K.; Bosch, G.; Vanhaecke, L.; Velde, van de H.; Depauw, S.; Xu, J.; Fievez, V.; Wiele, van der T.; Hendriks, W.H.; Janssens, G.P.J.; Hesta, M.

    2013-01-01

    This study aimed to evaluate correlations between fermentation characteristics and end products of selected fermentable fibres (three types of fructans, citrus pectin, guar gum), incubated with faecal inocula from donor cats fed two diets, differing in fibre and protein sources and concentrations. C

  18. Production of Functional High-protein Beverage Fermented with Lactic Acid Bacteria Isolated from Korean Traditional Fermented Food.

    Science.gov (United States)

    Cho, Young-Hee; Shin, Il-Seung; Hong, Sung-Moon; Kim, Cheol-Hyun

    2015-01-01

    The aim of this study was to manufacture functional high protein fermented beverage, using whey protein concentrate (WPC) and Lactobacillus plantarum DK211 isolated from kimchi, and to evaluate the physicochemical, functional, and sensory properties of the resulting product. The fermented whey beverage (FWB) was formulated with whey protein concentrate 80 (WPC 80), skim milk powder, and sucrose; and fermented with Lactobacillus plantarum DK211 as single, or mixed with Lactococcus lactis R704, a commercial starter culture. The pH, titratable acidity, and viable cell counts during fermentation and storage were evaluated. It was found that the mixed culture showed faster acid development than the single culture. The resulting FWB had high protein (9%) and low fat content (0.2%). Increased viscosity, and antioxidant and antimicrobial activity were observed after fermentation. A viable cell count of 10(9) CFU/mL in FWB was achieved within 10 h fermentation, and it remained throughout storage at 15℃ for 28 d. Sensory analysis was also conducted, and compared to that of a commercial protein drink. The sensory scores of FWB were similar to those of the commercial protein drink in most attributes, except sourness. The sourness was highly related with the high lactic acid content produced during fermentation. The results showed that WPC and vegetable origin lactic acid bacteria isolated from kimchi might be used for the development of a high protein fermented beverage, with improved functionality and organoleptic properties. PMID:26761827

  19. Microbiota dynamics related to environmental conditions during the fermentative production of Fen-Daqu, a Chinese industrial fermentation starter

    NARCIS (Netherlands)

    Zheng, Xiao-Wei; Yan, Zheng; Nout, M J Robert; Smid, Eddy J; Zwietering, Marcel H; Boekhout, Teun; Han, Jian-Shu; Han, Bei-Zhong

    2014-01-01

    Chinese Daqu is used as a starter for liquor and vinegar fermentations. It is produced by solid state fermentation of cereal-pulse mixtures. A succession of fungi, lactic acid bacteria and Bacillus spp. was observed during the production of Daqu. Mesophilic bacteria followed by fungi, dominated the

  20. Microbiota dynamics related to environmental conditions during the fermentative production of Fen-Daqu, a Chinese industrial fermentation starter

    NARCIS (Netherlands)

    Zheng, X.; Yan, Z.; Nout, M.J.R.; Smid, E.J.; Zwietering, M.H.; Boekhout, T.; Han, J.S.; Han, B.

    2014-01-01

    Chinese Daqu is used as a starter for liquor and vinegar fermentations. It is produced by solid state fermentation of cereal–pulse mixtures. A succession of fungi, lactic acid bacteria and Bacillus spp. was observed during the production of Daqu. Mesophilic bacteria followed by fungi, dominated the

  1. Comparative in vitro fermentation activity in the canine distal gastrointestinal tract and fermentation kinetics of fiber sources

    NARCIS (Netherlands)

    Bosch, G.; Pellikaan, W.F.; Rutten, P.G.P.; Poel, van der A.F.B.; Verstegen, M.W.A.; Hendriks, W.H.

    2008-01-01

    The current study aimed to evaluate the variation in fermentation activity along the distal canine gastrointestinal tract (GIT, Exp. 1). It also aimed to assess fermentation kinetics and end product profiles of 16 dietary fibers for dog foods using canine fecal inoculum (Exp. 2). For Exp. 1, digesta

  2. Fermentation and microflora of plaa-som, a Thai fermented fish product prepared with different salt concentrations

    DEFF Research Database (Denmark)

    Paludan-Müller, Christine; Madsen, M.; Sophanodora, P.;

    2002-01-01

    Plaa-som is a Thai fermented fish product prepared from snakehead fish, salt, palm syrup and sometimes roasted rice. We studied the effects of different salt concentrations on decrease in pH and on microflora composition during fermentation. Two low-salt batches were prepared, containing 6% and 7...

  3. Decontamination of biological ferment by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sabundjian, Ingrid T.; Salum, Debora C.; Silva, Priscila V.; Furgeri, Camilo; Duarte, Renato; Villavicencio, Anna Lucia C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: villavic@ipen.br

    2007-07-01

    Biological ferment is a product obtained from pure yeast (Saccharomyces cerevisiae) culture by a suitable technological process and employed to increase the size and porosity of the baker's products. Foods containing high microorganisms count indicate that Good Manufacturing Practices were not applied. The aim of this study was to observe the viability of Dry Biological Ferment after the radiation process using different doses of {sup 60}Co gamma rays and different storage times. Dry baker's yeast Saccharomyces cerevisiae samples were purchased from a local supermarket in Sao Paulo (Brazil) and irradiated at IPEN in a Gammacell source at 0.5, 1.0, 2.0 and 3.0 kGy doses (dose-rate of 3.51 kGy/h) at room temperature (25 deg C). The fluorescent method was performed to observe the viability of yeast cells. The viability decrease with the increase of the radiation dose, as shown: the amount of the viable cell found in the non-irradiated samples (control) at 0 day was 87.2%; 30 days 67.7%; 60 days 77.4% and 90 days 60.1%. With 1.0 kGy at 0 day was 61.4%; 30 days 22.7%; 60 days 56.9% and 90 days 24.2%. With 3.0 kGy at 0 day was 57.00%; at the next periods the most of the cells become not viable. (author)

  4. Chitooligosaccharides as novel ingredients of fermented foods.

    Science.gov (United States)

    Vela Gurovic, M S; Dello Staffolo, M; Montero, M; Debbaudt, A; Albertengo, L; Rodríguez, M S

    2015-11-01

    Chitooligosaccharides (COSs) have been clinically evaluated for their immunostimulating effects after oral intake. Similar to dietary supplements, prebiotics and biopreservatives, these water-soluble bioactives are easily incorporated into dairy products and beverages. Notwithstanding, the use of COS in fermented foods would be limited by its antimicrobial properties. In order to study the interaction with yoghurts as a model of fermented food, the effects of COS on chemical composition, viability, morphology and metabolism of lactic acid bacteria, fatty acid profiles and conjugated linoleic acid (CLA) were assessed over 28 days and after chemical digestion. There were no significant differences between the nutritional composition of controls and yoghurts supplemented with concentrations up to 0.1% w/w of COS. However, the acidification of milk decreased at 0.5% (p < 0.05) and the formation of yoghurt failed at 3.0%, without affecting viable counts. Lipid hydrolysis of yoghurts supplemented with 0.1% COS was not affected by chemical digestion. No significant differences were found between CLA percentages of controls and supplemented yoghurts after digestion. Although the nutritional composition, fatty acids and viable counts were not significantly modified after COS supplementation, the present study shows that COS diminishes bacterial acidification at concentrations higher than 0.1%, thus limiting the amounts that could be added to yoghurt. PMID:26301404

  5. Fermented probiotic beverages based on acid whey

    Directory of Open Access Journals (Sweden)

    Katarzyna Skryplonek

    2015-12-01

    Full Text Available Background. Production of fermented probiotic beverages can be a good method for acid whey usage. The obtained products combine a high nutritional value of whey with health benefits claimed for probiotic bac- teria. The aim of the study was to define quality properties of beverages based on fresh acid whey and milk with addition of buttermilk powder or sweet whey powder. Material and methods. Samples were inoculated with two strains of commercial probiotic cultures: Lac- tobacillus acidophilus La-5 or Bifidobacterium animalis Bb-12. After fermentation, samples were stored at refrigerated conditions. After 1, 4, 7, 14 and 21 days sensory characteristics, hardness, acetaldehyde content, titratable acidity, pH acidity and count of bacteria cells were evaluated. Results. Throughout all storage period, the number of bacteria was higher than 8 log cfu/ml in the all sam- ples. Beverages with La-5 strain had higher hardness and acidity, whilst samples with Bb-12 contained more acetaldehyde. Samples with buttermilk powder had better sensory properties than with sweet whey powder. Conclusions. Obtained products made of acid whey combined with milk and fortified with buttermilk pow- der or sweet whey powder, are good medium for growth and survival of examined probiotic bacteria strains. The level of bacteria was sufficient to provide health benefits to consumers.

  6. Oxidative stability of fermented meat products

    Directory of Open Access Journals (Sweden)

    Zbigniew J. Dolatowski

    2012-06-01

    Full Text Available Meat and meat products, which form a major part of our diet, are very susceptible to quality changes resulting from oxidative processes. Quality of fermented food products depends on the course of various physicochemical and biochemical processes. Oxidation of meat components in raw ripening products may be the result of enzymatic changes occurring as a result of activity of enzymes originating in tissues and microorganisms, as well as lipid peroxidation by free radicals. Primary and secondary products of lipid oxidation are extremely reactive and react with other components of meat, changing their physical and chemical properties. Oxidised proteins take on a yellowish, red through brown hue. Products of lipid and protein degradation create a specifi c fl avour and aroma ; furthermore, toxic substances (such as biogenic amines or new substances are formed as a result of interactions between meat components, e.g. protein-lipid or protein-protein combinations, as well as transverse bonds in protein structures. Oxidation of meat components in raw ripening products is a particularly diffi cult process. On the one hand it is essential, since the enzymatic and non-enzymatic lipid oxidation creates fl avour and aroma compounds characteristic for ripening products; on the other hand excessive amounts or transformations of those compounds may cause the fermented meat product to become a risk to health.

  7. Heat transfer simulation in solid substrate fermentation.

    Science.gov (United States)

    Saucedo-Castañeda, G; Gutiérrez-Rojas, M; Bacquet, G; Raimbault, M; Viniegra-González, G

    1990-04-01

    A mathematical model was developed and tested to simulate the generation and transfer of heat in solid substrate fermentation (SSF). The experimental studies were realized in a 1-L static bioreactor packed with cassava wet meal and inoculated with Aspergillus niger. A simplified pseudohomogeneous monodimensional dynamic model was used for the energy balance. Kinetic equations taking into account biomass formation (logistic), sugar consumption (with maintenance), and carbon dioxide formation were used. Model verification was achieved by comparison of calculated and experimental temperatures. Heat transfer was evaluated by the estimation of Biot and Peclet heat dimensionless numbers 5-10 and 2550-2750, respectively. It was shown that conduction through the fermentation fixed bed was the main heat transfer resistance. This model intends to reach a better understanding of transport phenomena in SSF, a fact which could be used to evaluate various alternatives for temperature control of SSF, i.e., changing air flow rates and increasing water content. Dimensionless numbers could be used as scale-up criteria of large fermentors, since in those ratios are described the operating conditions, geometry, and size of the bioreactor. It could lead to improved solid reactor systems. The model can be used as a basis for automatic control of SSF for the production of valuable metabolites in static fermentors.

  8. Fourth-order gravity as the inflationary model revisited

    CERN Document Server

    Kaneda, S; Watanabe, N

    2010-01-01

    We revisit the simplest (fourth-order or quadratically generated) modified gravity model in four space-time dimensions. It is equivalent to the certain quintessence model via a Legendre-Weyl transform. By using the quintessence scalar potential we compute the (CMB) observables of inflation associated with curvature perturbations (namely, the scalar and tensor spectral indices, and the tensor-to-scalar ratio) by using the most recent WMAP5 experimental bound. Our results include the next-to-leading terms with respect to the inverse number of e-foldings.

  9. Revisiting the issue of elite capture in participatory initiatives

    DEFF Research Database (Denmark)

    Lund, Jens Friis; Saito-Jensen, Moeko

    2013-01-01

    of resistance orchestrated by initially disadvantaged groups. Based on the cases we argue that studies of elite capture should be based on in-depth and longitudinal empirical investigations that carefully characterize forms and outcomes of elite capture and consider both the changing dynamics of social settings......Based on case studies of two communities implementing participatory forestry in Tanzania and India, we revisit the issue of elite capture of participatory initiatives. Our cases illustrate how initial elite capture of the participatory initiatives is circumvented over time through various forms...

  10. Hyperbranched polymer stars with Gaussian chain statistics revisited.

    Science.gov (United States)

    Polińska, P; Gillig, C; Wittmer, J P; Baschnagel, J

    2014-02-01

    Conformational properties of regular dendrimers and more general hyperbranched polymer stars with Gaussian statistics for the spacer chains between branching points are revisited numerically. We investigate the scaling for asymptotically long chains especially for fractal dimensions df = 3 (marginally compact) and df = 2.5 (diffusion limited aggregation). Power-law stars obtained by imposing the number of additional arms per generation are compared to truly self-similar stars. We discuss effects of weak excluded-volume interactions and sketch the regime where the Gaussian approximation should hold in dense solutions and melts for sufficiently large spacer chains. PMID:24574057

  11. Revisiting perfect fluid dark matter: Observational constraints from our galaxy

    OpenAIRE

    Potapov, Alexander A.; Garipova, Guzel M.; Nandi, Kamal K.

    2016-01-01

    We revisit certain features of an assumed spherically symmetric perfect fluid dark matter halo in the light of the observed data of our galaxy, the Milky Way (MW). The idea is to apply the Faber–Visser approach of combined observations of rotation curves and lensing to a first post-Newtonian approximation to “measure” the equation of state ω(r) of the perfect fluid galactic halo. However, for the model considered here, no constraints from lensing are used as it will be sufficient to consider ...

  12. Sampling the equilibrium: the j-walking algorithm revisited

    CERN Document Server

    Rimas, Zilvinas

    2016-01-01

    The j-walking Monte-Carlo algorithm is revisited and updated to study the equilibrium properties of a system exhibiting broken ergodicity. The updated algorithm is tested on the Ising model and applied to the lattice-gas model for sorption in aerogel at low temperatures, when dynamics of the system is critically slowed down. It is demonstrated that the updated j-walking simulations are able to produce equilibrium isotherm which are typically hidden by the hysteresis effect within the standard single-flip simulations.

  13. Nonextensive Nambu Jona-Lasinio model of QCD matter revisited

    CERN Document Server

    Rozynek, Jacek

    2016-01-01

    We present a revisited version of the nonextensive QCD-based Nambu - Jona-Lasinio (NJL) model describing the behavior of strongly interacting matter proposed by us some time ago. As before, it is based on the nonextensive generalization of the Boltzmann-Gibbs (BG) statistical mechanics used in the NJL model to its nonextensive version based on Tsallis statistics, but this time it fulfils the basic requirements of thermodynamical consistency. Different ways in which this can be done, connected with different possible choices of the form of the corresponding nonextensive entropies, are presented and discussed in detail. The corresponding results are compared, discussed and confronted with previous findings.

  14. Closed-set-based Discovery of Representative Association Rules Revisited

    CERN Document Server

    Balcázar, José L

    2010-01-01

    The output of an association rule miner is often huge in practice. This is why several concise lossless representations have been proposed, such as the "essential" or "representative" rules. We revisit the algorithm given by Kryszkiewicz (Int. Symp. Intelligent Data Analysis 2001, Springer-Verlag LNCS 2189, 350-359) for mining representative rules. We show that its output is sometimes incomplete, due to an oversight in its mathematical validation, and we propose an alternative complete generator that works within only slightly larger running times.

  15. Revisiting reflexology: Concept, evidence, current practice, and practitioner training

    OpenAIRE

    Embong, Nurul Haswani; Soh, Yee Chang; Ming, Long Chiau; Wong, Tin Wui

    2015-01-01

    Reflexology is basically a study of how one part of the human body relates to another part of the body. Reflexology practitioners rely on the reflexes map of the feet and hands to all the internal organs and other human body parts. They believe that by applying the appropriate pressure and massage certain spots on the feet and hands, all other body parts could be energized and rejuvenated. This review aimed to revisit the concept of reflexology and examine its effectiveness, practices, and th...

  16. Small-angle scattering theory revisited: Photocurrent and spatial localization

    DEFF Research Database (Denmark)

    Basse, N.P.; Zoletnik, S.; Michelsen, Poul

    2005-01-01

    In this paper theory on collective scattering measurements of electron density fluctuations in fusion plasmas is revisited. We present the first full derivation of the expression for the photocurrent beginning at the basic scattering concepts. Thereafter we derive detailed expressions for the auto......- and crosspower spectra obtained from measurements. These are discussed and simple simulations made to elucidate the physical meaning of the findings. In this context, the known methods of obtaining spatial localization are discussed and appraised. Where actual numbers are applied, we utilize....... Saffman et al., "CO2 laser based two-volume collective scattering instrument for spatially localized turbulence measurements,"Rev. Sci. Instrum. 72, 2579-2592 (2001)]....

  17. Jir hur a Fermented Millet (Penisitum typhoidism Product of Sudan

    Directory of Open Access Journals (Sweden)

    K.H. Samah

    2011-07-01

    Full Text Available Jir hur is a traditional fermented food of the Fur tribe of western Sudan prepared from bulrush millet (Penisitum typhoidism. The microbiological changes during the fermentation stages were monitored. LAB count increased from 4.48 in raw millet to 7.19 log/cfug in jir hur and yeast count increased from 3.77 to 7.55 log/cfug, respectively with significant changes in pH from 6.66 in raw millet to 3.68 in jir hur. The fermentation of millet into jir was a homo-lactic acid fermentation that involved a complex microbial succession between LAB and yeast. LAB was the predominant microorganisms during the first fermentation with significant increase in yeast counts. Pediococcus halophilus, Pediococcus inopinatus and Pediococcus urinaeequi were the dominant lactic acid bacteria species at all times with the association of Lactobacillus acidophilus and Lactobacillus jensenii at the second fermentation. The yeast species Schizosaccharomyces pombe, Saccharomycods sinensis and Trichosporon adeninovorans were followed in succession during jir fermentation stages.

  18. Fermentation of aqueous plant seed extracts by lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Schafner, D.W.; Beuchat, R.L.

    1986-05-01

    The effects of lactic acid bacterial fermentation on chemical and physical changes in aqueous extracts of cowpea (Vigna unguiculata), peanut (Arachis hypogea), soybean (Glycine max), and sorghum (Sorghum vulgare) were studied. The bacteria investigated were Lactobacillus helveticus, L. delbrueckii, L. casei, L. bulgaricus, L. acidophilus, and Streptococcus thermophilus. Organisms were inoculated individually into all of the seed extracts; L. bulgaricus and S. thermophilus were also evaluated together as inocula for fermenting the legume extracts. During fermentation, bacterial population and changes in titratable acidity, pH, viscosity, and color were measured over a 72 h period at 37 degrees C. Maximum bacterial populations, titratable acidity, pH, and viscosity varied depending upon the type of extract and bacterial strain. The maximum population of each organism was influenced by fermentable carbohydrates, which, in turn, influenced acid production and change in pH. Change in viscosity was correlated with the amount of protein and titratable acidity of products. Color was affected by pasteurization treatment and fermentation as well as the source of extract. In the extracts inoculated simultaneously with L. bulgaricus and S. thermophilus, a synergistic effect resulted in increased bacterial populations, titratable acidity, and viscosity, and decreased pH in all the legume extracts when compared to the extracts fermented with either of these organisms individually. Fermented extracts offer potential as substitutes for cultured dairy products. 24 references.

  19. The Biotechnology of Ugba, a Nigerian Traditional Fermented Food Condiment.

    Science.gov (United States)

    Olasupo, Nurudeen A; Okorie, Chimezie P; Oguntoyinbo, Folarin A

    2016-01-01

    Legumes and oil bean seeds used for the production of condiments in Africa are inedible in their natural state; they contain some anti-nutritional factors especially undigestible oligosaccharides and phytate. Fermentation impact desirable changes by reducing anti-nutritional factors and increasing digestibility. Ugba is an alkaline fermented African oil bean cotyledon (Pentaclethra macrophylla) produced by the Ibos and other ethnic groups in southern Nigeria. Seen as a family business in many homes, its preparation is in accordance with handed-down tradition from previous generations and serves as a cheap source of plant protein. Its consumption as a native salad is made possible by fermentation of the cotyledon for 2-5 days, but could also serve as a soup flavoring agent when fermentation last for 6-10 days. The fermentation process involved is usually natural with an attendant issue of product safety, quality and inconsistency. The production of this condiment is on a small scale and the equipment used are very rudimentary, devoid of good manufacturing procedures that call to question the issue of microbial safety. This paper therefore reviews the production process and the spectrum of microbial composition involved during fermentation. In addition, potential spoilage agents, nutritional and biochemical changes during production are examined. Furthermore, information that can support development of starter cultures for controlled fermentation process in order to guarantee microbiological safety, quality and improved shelf life are also discussed. PMID:27540371

  20. Physicochemical and functional properties of yeast fermented brown rice flour.

    Science.gov (United States)

    Ilowefah, Muna; Bakar, Jamilah; Ghazali, Hasanah M; Mediani, Ahmed; Muhammad, Kharidah

    2015-09-01

    In the current study, effects of fermentation on physicochemical and functional properties of brown rice flour (BRF) were investigated. Fermentation conditions were optimized using response surface methodology to achieve moderate acidity (pH 5-6), specifically pH 5.5 of brown rice batter with time, temperature and yeast concentration as the independent variables. The results indicated that brown rice batter was well fermented to maintain pH 5.5 at optimum conditions of 32 °C for 6.26 h using 1 % yeast concentration. Fermentation at moderate acidity significantly increased the levels of protein, total ash, insoluble fiber, soluble fibre, minerals, phenolics, antioxidants, resistant starch, riboflavin, pyridoxine, nicotinic acid, γ-tocotrienol, and δ-tocotrienol. However, it reduced the contents of γ-oryzanol, γ-tocopherol, α-tocopherol, phytic acid, amylose and total starch. Foaming capacity, foaming stability, oil holding capacity, gelatinization temperatures, enthalpy and whiteness of BRF were increased after fermentation. In contrast, its swelling power, water solubility index, hot paste viscosity, breakdown, and setback significantly decreased. Microstructure of BRF was also influenced, where its starch granules released from its enclosed structure after fermentation. This investigation shows evidence that yeast fermentation modified the functionality of BRF and can be used as a functional food ingredient. PMID:26344967

  1. Induction of simultaneous and sequential malolactic fermentation in durian wine.

    Science.gov (United States)

    Taniasuri, Fransisca; Lee, Pin-Rou; Liu, Shao-Quan

    2016-08-01

    This study represented for the first time the impact of malolactic fermentation (MLF) induced by Oenococcus oeni and its inoculation strategies (simultaneous vs. sequential) on the fermentation performance as well as aroma compound profile of durian wine. There was no negative impact of simultaneous inoculation of O. oeni and Saccharomyces cerevisiae on the growth and fermentation kinetics of S. cerevisiae as compared to sequential fermentation. Simultaneous MLF did not lead to an excessive increase in volatile acidity as compared to sequential MLF. The kinetic changes of organic acids (i.e. malic, lactic, succinic, acetic and α-ketoglutaric acids) varied with simultaneous and sequential MLF relative to yeast alone. MLF, regardless of inoculation mode, resulted in higher production of fermentation-derived volatiles as compared to control (alcoholic fermentation only), including esters, volatile fatty acids, and terpenes, except for higher alcohols. Most indigenous volatile sulphur compounds in durian were decreased to trace levels with little differences among the control, simultaneous and sequential MLF. Among the different wines, the wine with simultaneous MLF had higher concentrations of terpenes and acetate esters while sequential MLF had increased concentrations of medium- and long-chain ethyl esters. Relative to alcoholic fermentation only, both simultaneous and sequential MLF reduced acetaldehyde substantially with sequential MLF being more effective. These findings illustrate that MLF is an effective and novel way of modulating the volatile and aroma compound profile of durian wine. PMID:27104664

  2. Study on the Quality Control of Chinese Jujube Wine Fermentation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bao-shan; CHEN Jin-ping; LI Hui-yun

    2004-01-01

    Fermentation processes were studied,with an aim of improving the quality of Chinese jujube wine.Results showed the quality of the wine made from fresh Chinese jujube and dried Chinese jujube were similar,but wine made from excessively dried Chinese jujube showed decreased quality.The reducing sugar content in Chinese jujube juice extracted by pectic enzymes was higher than the reducing sugar content extracted by hot water,however,methanol content in wine extracted by pectic enzymes also increased.Therefore the hot water extraction method is recommended for fermentation of Chinese jujube wine.Fermentation using vacuum concentrated Chinese jujube juice was more effective than that using filtered juice readjusted to 20% soluble solid content .(SSC) with sucrose or glucose.The inoculation of 0.3% Saccharomyces ellipsodieus Strain was suitable for fermentation of Chinese jujube wine.Fermentation was carried out at 21-25℃.The concentration of SO2 in wine affected fermentation time and the optimum additional amount was 40 mg L-1.Post fermentation storage in oak barrel improved the quality of Chinese jujube wine,as did 4.5% diatomite filtration.

  3. Safety evaluation of rebaudioside A produced by fermentation.

    Science.gov (United States)

    Rumelhard, Mélina; Hosako, Hiromi; Eurlings, Irene M J; Westerink, Walter M A; Staska, Lauren M; van de Wiel, Jeanine A G; La Marta, James

    2016-03-01

    The safety of rebaudioside A, produced fermentatively by Yarrowia lipolytica encoding the Stevia rebaudiana metabolic pathway (fermentative Reb A), is based on several elements: first, the safety of steviol glycosides has been extensively evaluated and an acceptable daily intake has been defined; second, the use of Y. lipolytica, an avirulent yeast naturally found in foods and used for multiple applications; and third the high purity of fermentative Reb A and its compliance with internationally defined specifications. A bacterial reverse mutation assay and an in vitro micronucleus test conducted with fermentative Reb A provide evidence for its absence of mutagenicity, clastogenicity and aneugenicity. The oral administration of fermentative Reb A to Sprague-Dawley rats for at least 91 days did not lead to any adverse effects at consumption levels up to 2057 mg/kg bw/day for males and 2023 mg/kg bw/day for females, which were concluded to be the No Observed Adverse Effect Levels. The results were consistent with outcomes of previous studies conducted with plant-derived rebaudioside A, suggesting similar safety profiles for fermentative and plant-derived rebaudioside A. The results of the toxicity studies reported here support the safety of rebaudioside A produced fermentatively from Y. lipolytica, as a general purpose sweetener. PMID:26776281

  4. The Biotechnology of Ugba, a Nigerian Traditional Fermented Food Condiment

    Science.gov (United States)

    Olasupo, Nurudeen A.; Okorie, Chimezie P.; Oguntoyinbo, Folarin A.

    2016-01-01

    Legumes and oil bean seeds used for the production of condiments in Africa are inedible in their natural state; they contain some anti-nutritional factors especially undigestible oligosaccharides and phytate. Fermentation impact desirable changes by reducing anti-nutritional factors and increasing digestibility. Ugba is an alkaline fermented African oil bean cotyledon (Pentaclethra macrophylla) produced by the Ibos and other ethnic groups in southern Nigeria. Seen as a family business in many homes, its preparation is in accordance with handed-down tradition from previous generations and serves as a cheap source of plant protein. Its consumption as a native salad is made possible by fermentation of the cotyledon for 2–5 days, but could also serve as a soup flavoring agent when fermentation last for 6–10 days. The fermentation process involved is usually natural with an attendant issue of product safety, quality and inconsistency. The production of this condiment is on a small scale and the equipment used are very rudimentary, devoid of good manufacturing procedures that call to question the issue of microbial safety. This paper therefore reviews the production process and the spectrum of microbial composition involved during fermentation. In addition, potential spoilage agents, nutritional and biochemical changes during production are examined. Furthermore, information that can support development of starter cultures for controlled fermentation process in order to guarantee microbiological safety, quality and improved shelf life are also discussed. PMID:27540371

  5. Revealing the factors influencing a fermentative biohydrogen production process using industrial wastewater as fermentation substrate

    OpenAIRE

    Boboescu, Iulian Zoltan; Ilie, Mariana; Vasile Daniel GHERMAN; Mirel, Ion; Pap, Bernadett; Negrea, Adina; Kondorosi, Éva; Bíró, Tibor; Maróti, Gergely

    2014-01-01

    Background Biohydrogen production through dark fermentation using organic waste as a substrate has gained increasing attention in recent years, mostly because of the economic advantages of coupling renewable, clean energy production with biological waste treatment. An ideal approach is the use of selected microbial inocula that are able to degrade complex organic substrates with simultaneous biohydrogen generation. Unfortunately, even with a specifically designed starting inoculum, there is s...

  6. Some microbiological aspects of cassava fermentation with emphasis on detoxification of the fermented end-product

    International Nuclear Information System (INIS)

    The search undertaken in this study was for microbial strains able to produce amylase and linamarase simultaneously. A total of 46 organisms (mainly yeasts) were isolated from garri production environments and eighteen more representative isolates were selected for screening. The highest production fo the above enzymes has been found with the yeast strain identified as Saccharomyces sp. Inoculation of this into the cassava mash led to a dramatic reduction of cyanide in the fermenting pulp: 73,4% and 69,2% reduction when compared with controls after 24 and 48 hours of fermentation respectively. The cyanide content of the fermented end-product derived from the inoculated mash was 60,8% and 24% less than in the control after 24 and 48 hours. Preliminary experiments with X-ray radiation of the yeast did not show a sufficient increase in the enzymatic activities of the mutants obtained but only a slight increase in the linamarase production was noticed in mutants derived from irradiation. (author). 27 refs, 9 tabs

  7. Effects of end products on fermentation profiles in Clostridium carboxidivorans P7 for syngas fermentation.

    Science.gov (United States)

    Zhang, Jie; Taylor, Steven; Wang, Yi

    2016-10-01

    Clostridium carboxidivorans P7 is a strict anaerobic bacterium capable of converting syngas to biofuels. However, its fermentation profiles is poorly understood. Here, various end-products, including acetic acid, butyric acid, hexanoic acid, ethanol and butanol were supplemented to evaluate their effects on fermentation profiles in C. carboxidivorans at two temperatures. At 37°C, fatty acids addition likely led to more corresponding alcohols production. At 25°C, C2 and C4 fatty acids supplementation resulted in more corresponding higher fatty acids, while supplemented hexanoic acid increased yields of C2 and C4 fatty acids and hexanol. Supplementation of ethanol or butanol caused increased production of C2 and C4 acids at both temperatures; however, long-chain alcohols were still more likely produced at lower temperature. In conclusion, fermentation profiles of C. carboxidivorans can be changed in respond to pre-added end-products and carbon flow may be redirected to desired products by controlling culture conditions. PMID:27459682

  8. PEI detoxification of pretreated spruce for high solids ethanol fermentation

    DEFF Research Database (Denmark)

    Cannella, David; Sveding, Per Viktor; Jørgensen, Henning

    2014-01-01

    ethanol production from spruce performing the whole process, from pretreatment to hydrolysis and fermentation, at 30% dry matter (equivalent to similar to 20% WIS). Hydrolysis and fermentation was performed in a horizontal free fall mixing reactor enabling efficient mixing at high solids loadings....... In batch simultaneous saccharification and fermentation (SSF), up to 76% cellulose to ethanol conversion was achieved resulting in a concentration of 51 g/kg of ethanol. Key to obtaining this high ethanol yield at these conditions was the use of a detoxification technology based on applying a soluble...

  9. ADAPTIVE CONTROL OF FEED LOAD CHANGES IN ALCOHOL FERMENTATION

    Directory of Open Access Journals (Sweden)

    Folly R.

    1997-01-01

    Full Text Available A fed-batch alcohol fermentation on a pilot plant scale with a digital supervisory control system was evaluated as an experimental application case study of an adaptive controller. The verification of intrinsically dynamic variations in the characteristics of the fermentation, observed in previous work, showed the necessity of an adaptive control strategy for controller parameter tuning in order to adjust the changes in the specific rates of consumption, growth and product formation during the process. Satisfactory experimental results were obtained for set-point variations and sugar feed concentration load changes in the manipulated inlet flow to the fermenter

  10. Occurrence and function of yeasts in Asian indigenous fermented foods.

    Science.gov (United States)

    Aidoo, Kofi E; Nout, M J Rob; Sarkar, Prabir K

    2006-01-01

    In the Asian region, indigenous fermented foods are important in daily life. In many of these foods, yeasts are predominant and functional during the fermentation. The diversity of foods in which yeasts predominate ranges from leavened bread-like products such as nan and idli, to alcoholic beverages such as rice and palm wines, and condiments such as papads and soy sauce. Although several products are obtained by natural fermentation, the use of traditional starter cultures is widespread. This minireview focuses on the diversity and functionality of yeasts in these products, and on opportunities for research and development. PMID:16423068

  11. Features of fiber fermentation under bifidobacteria and lactobacilli (in vitro

    Directory of Open Access Journals (Sweden)

    Sedakova Valentina

    2016-02-01

    Full Text Available The article presents experimental data on the study of fermentation of dietary fibers of different origin under the action of bifidobacteria and lactobacilli. Citrus and apple pectin, flax fiber and glucose were used as substrate. The dynamics of the process was determined by the dependence of the content of short-chain fatty acids (propionic, butyric, valeric in the analyzed systems on time. Qualitative and quantitative composition of shot-chain fatty acids were determined by gas chromatography. It was found that the amount of metabolites (propionic, butyric and isovaleric acids depends both on the type of the fermentable substrate, and the type of bacteria used for fermentation.

  12. Prebiotics, Fermentable Dietary Fiber, and Health Claims.

    Science.gov (United States)

    Delcour, Jan A; Aman, Per; Courtin, Christophe M; Hamaker, Bruce R; Verbeke, Kristin

    2016-01-01

    Since the 1970s, the positive effects of dietary fiber on health have increasingly been recognized. The collective term "dietary fiber" groups structures that have different physiologic effects. Since 1995, some dietary fibers have been denoted as prebiotics, implying a beneficial physiologic effect related to increasing numbers or activity of the gastrointestinal microbiota. Given the complex composition of the microbiota, the demonstration of such beneficial effects is difficult. In contrast, an exploration of the metabolites of dietary fiber formed as a result of its fermentation in the colon offers better perspectives for providing mechanistic links between fiber intake and health benefits. Positive outcomes of such studies hold the promise that claims describing specific health benefits can be granted. This would help bridge the "fiber gap"-that is, the considerable difference between recommended and actual fiber intakes by the average consumer.

  13. Multivariate analysis of industrial scale fermentation data

    DEFF Research Database (Denmark)

    Mears, Lisa; Nørregård, Rasmus; Stocks, Stuart;

    , and thereforeareas offocus for optimising the processoperation.This requires multivariate methods which canutilise the complexdatasetswhich areroutinely collected, containing online measured variables and offline sample data.Fermentation processes are highly sensitive to operational changes, as well as between...... the operation[3], which makestraditional modelling a challenge.Although multivariate techniques are routinely used for chemometric applications, theirapplication to batch processes islesscommon due to the additional challenges associated withuneven batch lengths and less reproducible data, which has naturally...... greater variability, as well ashigh measurement noise. This requires additional preprocessing stagesin order to extract theinformation within such a dataset.A 30 batch dataset from a production process operating at Novozymes A/Sis analysed bymultivariate analysis with the aim of predicting the final...

  14. Multivariate Analysis of Industrial Scale Fermentation Data

    DEFF Research Database (Denmark)

    Mears, Lisa; Nørregård, Rasmus; Stocks, Stuart M.;

    2015-01-01

    Multivariate analysis allows process understanding to be gained from the vast and complex datasets recorded from fermentation processes, however the application of such techniques to this field can be limited by the data pre-processing requirements and data handling. In this work many iterations...... of multivariate modelling were carried out using different data pre-processing and scaling methods in order to extract the trends from the industrial data set, obtained from a production process operating in Novozymes A/S. This data set poses challenges for data analysis, combining both online and offline...... variables, different data sampling intervals, and noise in the measurements, as well as different batch lengths. By applying unfold principal component regression (UPCR) and unfold partial least squares (UPLS) regression algorithms, the product concentration could be predicted for 30 production batches...

  15. Effect of fermentation conditions on the flocculation of recombinant Saccharomyces cerevisiae capable of co-fermenting glucose and xylose.

    Science.gov (United States)

    Matsushika, Akinori; Morikawa, Hiroyo; Goshima, Tetsuya; Hoshino, Tamotsu

    2014-09-01

    Flocculation is a desirable property in industrial yeasts and is particularly important in the fuel ethanol industry because it provides a simple and cost-free way to separate yeast cells from fermentation products. In the present study, the effect of pH and lignocellulose-derived sugars on yeast flocculation was investigated using a flocculent Saccharomyces cerevisiae, MA-R4, which has been recombinantly engineered to simultaneously co-ferment glucose and xylose to ethanol with high productivity. The flocculation level of MA-R4 dramatically decreased at pH values below 3.0 during co-fermentation of glucose and xylose. Sedimentation and microscopic observation revealed that flocculation was induced in MA-R4 when it fermented glucose, a glucose/xylose mixture, or mannose, whereas attempts to ferment xylose, galactose, and arabinose led to the loss of flocculation. MA-R4 fermented xylose and galactose more slowly than glucose and mannose. Therefore, the various flocculation behaviors shown by MA-R4 should be useful in the control of ethanol fermentation processes. PMID:25086918

  16. Exploring flavour-producing core microbiota in multispecies solid-state fermentation of traditional Chinese vinegar

    OpenAIRE

    Zong-Min Wang; Zhen-Ming Lu; Jin-Song Shi; Zheng-Hong Xu

    2016-01-01

    Multispecies solid-state fermentation (MSSF), a natural fermentation process driven by reproducible microbiota, is an important technique to produce traditional fermented foods. Flavours, skeleton of fermented foods, was mostly produced by microbiota in food ecosystem. However, the association between microbiota and flavours and flavour-producing core microbiota are still poorly understood. Here, acetic acid fermentation (AAF) of Zhenjiang aromatic vinegar was taken as a typical case of MSSF....

  17. Acetic Acid Production by an Electrodialysis Fermentation Method with a Computerized Control System

    OpenAIRE

    Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

    1988-01-01

    In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth an...

  18. Antagonism Between Osmophilic Lactic Acid Bacteria and Yeasts in Brine Fermentation of Soy Sauce

    OpenAIRE

    Noda, Fumio; HAYASHI, Kazuya; Mizunuma, Takeji

    1980-01-01

    Brine fermentation by osmophilic lactic acid bacteria and yeasts for long periods of time is essential to produce a good quality of shoyu (Japanese fermented soy sauce). It is well known that lactic acid fermentation by osmophilic lactic acid bacteria results in the depression of alcoholic fermentation by osmophilic yeasts, but the nature of the interaction between osmophilic lactic acid bacteria and yeasts in brine fermentation of shoyu has not been revealed. The inhibitory effect of osmophi...

  19. Vegetable milks and their fermented derivative products

    Directory of Open Access Journals (Sweden)

    Neus Bernat

    2014-04-01

    Full Text Available The so-called vegetable milks are in the spotlight thanks to their lactose-free, animal protein-free and cholesterol-free features which fit well with the current demand for healthy food products. Nevertheless, and with the exception of soya, little information is available about these types of milks and their derivatives. The aims of this review, therefore, are to: highlight the main nutritional benefits of the nut and cereal vegetable milks available on the market, fermented or not; describe the basic processing steps involved in their manufacturing process; and analyze the major problems affecting their overall quality, together with the current feasible solutions. On the basis of the information gathered, vegetable milks and their derivatives have excellent nutritional properties which provide them a high potential and positive market expectation. Nevertheless, optimal processing conditions for each raw material or the application of new technologies have to be researched in order to improve the quality of the products. Hence, further studies need to be developed to ensure the physical stability of the products throughout their whole shelf-life. These studies would also allow for a reduction in the amount of additives (hydrocolloids and/or emulsifiers and thus reduce the cost of the products. In the particular case of fermented products, the use of starters which are able to both improve the quality (by synthesizing enhanced flavors and providing optimal textures and exert health benefits for consumers (i.e. probiotics is the main challenge to be faced in future studies.

  20. Fermentative hydrogen production at high sulfate concentration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chin-Chao [Environmental Resources Laboratory, Department of Landscape Architecture, Chungchou Institute of Technology, Changhwa 51022 (China); Chen, Hong-Pin; Wu, Jou-Hsien; Lin, Chiu-Yue [BioHydrogen Laboratory, Department of Water Resource Engineering, Feng Chia University, P.O. Box 25-123, Taichung 40724 (China)

    2008-03-15

    The hydraulic retention time (HRT) effects on fermentative hydrogen production from sucrose at high sulfate concentration of 3 g-SO{sub 4}{sup 2-}/l were studied using enriched mixed-microflora in a continuously fed reactor. The tested HRTs and organic loading rate ranged from 10 to 2 h and 48 to 240 g-COD/l-day, respectively, and the operating pH was 5.5. The experimental results indicate that hydrogen production could not be inhibited under high sulfate concentration and the efficiency was HRT-dependent with a short HRT of 4 h efficiently enhanced hydrogen production. At this HRT the biogas production rate and hydrogen gas content peaked with the hydrogen yield, hydrogen production rate and specific hydrogen production rate of 4.70 mol-H{sub 2}/mol-sucrose, 874 mmol-H{sub 2}/l-day and 432 mmol-H{sub 2}/g-VSS-day, respectively. These values were 50%, 80% and 300%, respectively, higher than those reported for 12 h HRT at the same sulfate concentration. The metabolite concentration fractions were butyrate 77.3%, acetate 15.6%, ethanol 4.4% and propionate 2.0% and changed to 55%, 27.3%, 11.2% and 6.5%, respectively, at HRT 2 h. Therefore, intimate HRT control is important to obtain efficient hydrogen production. Based on a biological growth comparison, pH 5.5 was considered to be the optimal value for operating a hydrogen-producing fermenter fed on sulfate-rich substrate. (author)

  1. New inoculants on maize silage fermentation

    Directory of Open Access Journals (Sweden)

    Fábia Giovana do Val de Assis

    2014-08-01

    Full Text Available The objective of this study was to evaluate the effect of bacterial inoculants at two inoculation rates on chemical and biological characteristics of maize silage. The treatments consisted of two inoculating rates (5 and 6 log cfu g-1 of forage for each strain of lactic acid bacteria (LAB identified as Lactobacillus buchneri, L. hilgardii, or L. plantarum. The maize was ensiled in experimental PVC silos. Samples were taken for the determination of the contents of dry matter (DM, crude protein (CP, neutral detergent fiber (NDF, water-soluble carbohydrates (WSC, organic acids and alcohols, for the evaluation of the populations of lactic acid bacteria, yeasts, filamentous fungi, and for the determination of pH values during ensilage and after 30 or 90 days of fermentation. The doses of inoculants did not promote significant differences on the evaluated characteristics. There was effect of inoculants on acetic acid, 1.2-propanediol, LAB population, filamentous fungi, and pH value. No significant influence of the treatments with inoculants was observed in the variables DM, WSC, CP, lactic acid concentrations, or ethanol. The maximum temperature, i.e., the time to achieve the maximum temperature (TMT and aerobic stability (AS, was not influencied by treatments. However, a decrease in maximum temperature, an increase in TMT, and improvement in the AS were observed after 90 days of fermentation. These results proved the advantage of microbial inoculation. The treatments influenced LAB populations and filamentous fungi, but no effect was observed on the yeast population. The best inoculation dose is 6 cfu g-1 of forage because it provides higher reduction of filamentous fungi in maize silage, thereby decreasing the aerobic deterioration by these microorganisms.

  2. Effect of soy-fortification method on the fermentation characteristics and nutritional quality of fermented maize meal.

    Science.gov (United States)

    Plahar, W A; Nti, C A; Annan, N T

    1997-01-01

    Studies were conducted to develop an appropriate household/small-scale enterprise level technique for the production of soy-fortified fermented maize dough (or meal) by comparing different treatments, processing methods and fortification levels. The effects of fortification method of the Ghanaian traditional fermented maize dough with raw or heat-treated whole soybeans and full-fat soyflour at 0%, 10% and 20% replacement levels, on the rate of fermentation and product quality were investigated. Sensory characteristics, trypsin inhibitor activity, amino acid pattern, proximate composition and hot paste viscosity were used as the indices of quality. Addition of whole soybeans to maize before milling and fermentation reduced the fermentation time by 60% while increasing the protein content by 24% and 70% respectively for 10% and 20% levels of fortification. A significant improvement was also achieved in the amino acids pattern of the fortified dough. However, raw whole soybeans imparted an undesirable color and beany flavor and an appreciable concentration of trypsin inhibitor activity (TIA) to the dough. Boiling soybeans for 20 min before incorporation into the maize for milling and fermentation was found necessary for desirable flavor and low levels of TIA. Little or no changes in the pasting viscosity characteristics occurred in samples containing boiled soybeans, while the usual method of fortifying maize meal with soy flour was found to severely depress the pasting viscosity characteristics and drastically reduced the acidity of the fermented dough. Based on the findings of the study, the most appropriate technique for the production of soy-fortified high protein fermented maize dough has been suggested to involve incorporation of boiled whole soybeans in soaked maize before milling and fermentation for improved sensory characteristics, enhanced nutritive value and optimal functional properties. PMID:9650729

  3. DMPD: TLR signalling and activation of IRFs: revisiting old friends from the NF-kappaBpathway. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16006187 TLR signalling and activation of IRFs: revisiting old friends from the NF-kappaBpath...nalling and activation of IRFs: revisiting old friends from the NF-kappaBpathway. PubmedID 16006187 Title TL...R signalling and activation of IRFs: revisiting old friends from the NF-kappaBpath

  4. [The course of rumen fermentation during alkalosis in cows].

    Science.gov (United States)

    Zawadzki, W; Hejłasz, Z; Nicpoń, J

    1991-01-01

    The aim of the study was the investigation of rumen fermentation during alkalosis in cows. The study comprised some parameters of rumen fermentation, such as: pH, ammonia and volatile fatty acids (VFA) levels, also relationship between VFA, numbers of population of protozoa and bacteria, total production of gases in vitro particularly CO2 and CH4, amounts of lactic and total protein in rumen fluid and non-glucogenic/glucogenic ratio (NGGR) in the VFA mixture. On the basis of obtained results the amounts of fermented hexose, cell yield, ATP produced and hydrogen utilization were calculated. During alkalosis there was observed significant fall of VFA production, especially acetic and butyric acids, also lower production of gases, particularly CH4--probably as a result of selective reduction of methanogenic strain bacteria. The levelling of value of rumen pattern of fermentation occurred after the beginning of lactation probably as a result of metabolism products excretion together with milk. PMID:1842617

  5. Generalized Net Model of Brevibacterium flavul 22LD Fermentation Process

    Directory of Open Access Journals (Sweden)

    Olympia Roeva

    2005-04-01

    Full Text Available In order to render the specific peculiarities of the fermentation processes, as well as to avoid the complexity of mathematical description with systems of differential equations, the elaboration of some new methods and approaches for their modelling and control is predetermined. As a new, alternative approach for modelling of fermentation processes, an application of generalized nets is presented in this paper. The theory of generalized nets is applied to the fermentation process of Brevibacterium flavul 22LD for L-lysine production. A generalized net model of considered process is developed. For comparison and completeness, model with differential equations is also provided. The generalized nets model developed for the fed-batch cultivation of Brevibacterium flavul 22LD allows changing the concentration of the feeding solution and the aeration rate. In this way some inhibition effects are prevented and a possibility for optimal carrying out of the considered fermentation process is provided.

  6. Selection of a yeast strain for sweet sorghum fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Bowling, M. C.

    1982-01-01

    Seven natural and eight commercial yeast strains were tested for fermenting the high sugar content of sweet sorghum juice with a high yield of alcohol and a high pecentage utilization of the sugar within a ten day period. The sorghum juice pH was adjusted to range between 4 and 5. A comparison was made with and without an added nitrogen source. Fermentation temperatures were maintained at 27/sup 0/C. The American Type Culture Collection number 918, a Saccharomyces species fermented the sorghum juice at the 26 and 18 to 20 balling (brix). No yeast strain was found to ferment the 30 balling juice within a ten day period at 90% utilization.

  7. DNA fingerprinting of lactic acid bacteria in sauerkraut fermentations

    Science.gov (United States)

    Previous studies using traditional biochemical methods to study the ecology of commercial sauerkraut fermentations revealed that four lactic acid bacteria species, Leuconostoc mesenteroides, Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus brevis were the primary microorganisms in...

  8. Optimal control of switched systems arising in fermentation processes

    CERN Document Server

    Liu, Chongyang

    2014-01-01

    The book presents, in a systematic manner, the optimal controls under different mathematical models in fermentation processes. Variant mathematical models – i.e., those for multistage systems; switched autonomous systems; time-dependent and state-dependent switched systems; multistage time-delay systems and switched time-delay systems – for fed-batch fermentation processes are proposed and the theories and algorithms of their optimal control problems are studied and discussed. By putting forward novel methods and innovative tools, the book provides a state-of-the-art and comprehensive systematic treatment of optimal control problems arising in fermentation processes. It not only develops nonlinear dynamical system, optimal control theory and optimization algorithms, but can also help to increase productivity and provide valuable reference material on commercial fermentation processes.

  9. A New Pregnane Glycoside from Fermented Leaves of Agave americana

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new minor pregnane glycoside was isolated from the fermented leaves of Agave americana. Its structure was elucidated as (20S)-5α-pregnane-3β, 20-diol 20-O-β-D-glucopyrano- side (1) by spectral methods.

  10. Aeration-Controlled Formation of Acid in Heterolactic Fermentations

    DEFF Research Database (Denmark)

    Adler-Nissen, Jens

    1994-01-01

    by the buffer capacity only. Ethanol and acetic acid formed during the fermentation were analyzed by rapid head space gas chromatography, and the ratio of the molar concentrations of these two volatiles quantitatively predicted the balance between the formation of acetic acid and lactic acid. The oxygen......Controlled aeration of Leuconostoc mesenteroides was studied as a possible mechanism for control of the formation of acetic acid, a metabolite of major influence on the taste of lactic fermented foods. Fermentations were carried out in small scale in a medium in which growth was limited...... concentration during the fermentations decreased rapidly to zero, meaning that oxygen transfer was limited by the volumetric oxygen transfer rate, k1aC*. A linear correlation between k1aC* and the quantity of acetic acid produced was established, and it is suggested that such oxygenated heterolactic...

  11. The effect of kefir starter on Thai fermented sausage product

    Directory of Open Access Journals (Sweden)

    Marisa Jatupornpipat

    2007-07-01

    Full Text Available The effect of kefir starter from Wilderness Family Naturals Company on the initial formulation of Thai fermented sausage were evaluated. The differences found among batches in the main microbial populations and pH were not significant. Only, the total acid of batch D (added the kefir starter 15 ml was significantly higher (P0.05. It is concluded that the addition of kefir starter (7 ml could be useful to improve the final quality of Thai fermented sausages. The addition of kefir starter that initiates rapid acidification of the raw meat and that leads to a desirable sensory quality of the end-product are used for the production of fermented sausages, and represents a way of improving and optimizing the sausage fermentation process and achieving tastier, safer, and healthier products.

  12. Perspectives of Solid State Fermentation for Production of Food Enzymes

    Directory of Open Access Journals (Sweden)

    Cristobal Noe Aguilar

    2008-01-01

    Full Text Available Food industry represents one of the economic sectors where microbial metabolites have found a wide variety of applications. This is the case of some enzymes, such as amylases, cellulases, pectinases and proteases which have played a very important role as food additives. Most of these enzymes have been produced by submerged cultures at industrial level. Many works in the literature present detailed aspects involved with those enzymes and their importance in the food industry. However, the production and application studies of those enzymes produced by solid state fermentations are scarce in comparison with submerged fermentation. This review involves production aspects of the seven enzymes: tannases, pectinases, caffeinases, mannanases, phytases, xylanases and proteases, which can be produced by solid state fermentation showing attractive advantages. Additionally, process characteristics of solid state fermentation are considered.

  13. DETERMINATION OF ALCOHOL CONTENTS OF FERMENTATED BLACK TAPE KETAN BASED ON DIFFERENT FERMENTATION TIME USING SPECIFIC GRAVITY, REFRACTIVE INDEX AND GC-MS METHODS

    OpenAIRE

    Muchtaridi Muchtaridi; Ida Musfiroh; Nunu Nugraha Hambali; Wiwiek Indrayati

    2012-01-01

    Tape ketan is the product of fermentation process using black glutinous riceas basic ingredients, which then fermented for two to three days and finally produced tape ketan, organic acid and alcohol. The purpose of this research was to determine alcohol contents of fermentated black tape ketan based on different fermentation time with three diferent methods. Methods used are specific gravity, refractive index and GC-MS. Alcohol concentration obtained by using specific gravity method at 3, 10,...

  14. MACROSCOPIC KINETIC MODELS OF GLYCEROL BATCH FERMENTATION WITH OSMOTOLERANT YEAST

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    l introductionGlycerol production by fermentation has beenwidely investigated to meet the great commercialdemand in last decades and osmotolerant yeast wasthe microorganism studied most. To analyze thefermentation process more efficiently, a kinetic modelshould be established but little works about it werereported because of its complicated metabolism ofglycerol [1-3]. Batch fermentation experiment showedthat low glucose concentration in the latterfermentation stage resulted in decrease in both glucoseconsu...

  15. Lactic acid bacteria fermentations in oat-based suspensions

    OpenAIRE

    Mårtensson, Olof

    2002-01-01

    This thesis deals with the fermentation characteristics of lactic acid bacteria (LAB) in oat-based suspensions, with formulation work of fermented products based on oat and with nutritional studies of these products. Changes in structure in terms of viscosity and ropiness were studied when exopolysaccharide (EPS)-producing LAB strains, namely, Lactobacillus delbrueckii subsp. bulgaricus NCFB 2772, Lactobacillus brevis G-77 and Pediococcus damnosus 2.6 were grown in these oat-based suspensions...

  16. Optimal control of a fed-batch fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Dekkers, R.M.

    1984-01-01

    The common cultivation of bakers' yeast is an aerobic fed-batch fermentation under sugar-limited growth. The ultimate objective of on-line computer control is to optimize the process through maximizing the productivity of biomass formation while minimizing the consumption of raw materials for the product. Results obtained on the optimal control of a fed-batch fermentation are given. The aspects to be considered are instrumentation, state estimation, optimization and process control.

  17. Hydrodynamics of fermenter with multi-shaft stirrer

    OpenAIRE

    Закоморний, Дмитро Миколайович; Кутовий, Михайло Григорович; Костик, Сергій Ігорович; Поводзинський, Вадим Миколайович; Шибецький, Владислав Юрійович

    2016-01-01

    This article focuses on computer modeling of the hydrodynamic conditions in the fermenter with one-shaft and many-shafts mixing devices. On the basis of the research the features of formation of the vortex was found. Comparative analysis of hydrodynamic fluid flows that arising in volume by the usage of mixing devices of various designs was conducted. A modern design of many-shafts fermenter with avoidance of origin of vortex was made

  18. Fermentation and Hydrogen Metabolism Affect Uranium Reduction by Clostridia

    OpenAIRE

    Weimin Gao; Francis, Arokiasamy J.

    2013-01-01

    Previously, it has been shown that not only is uranium reduction under fermentation condition common among clostridia species, but also the strains differed in the extent of their capability and the pH of the culture significantly affected uranium(VI) reduction. In this study, using HPLC and GC techniques, metabolic properties of those clostridial strains active in uranium reduction under fermentation conditions have been characterized and their effects on capability variance of uranium reduc...

  19. Yield and Quality of Biogas from Anaerobic Fermentation of Grass

    OpenAIRE

    Poláček, Jan

    2014-01-01

    Biogas is generally considered as a renewable source of energy. In fact, however, it is biodegradable organic material, that makes this source of energy renewable. Biogas is, then, the final product of anaerobic fermentation of these materials. Because energetically the most valuable component of biogas is methane (CH4) its relative volume stands as the measure of biogas quality. The process of anaerobic fermentation was characterized in the first part of this thesis. Organic materials ar...

  20. Molecular characterization of lactobacilli isolated from fermented idli batter

    OpenAIRE

    Perumal Jayaprabha Agaliya; Kadirvelu Jeevaratnam

    2013-01-01

    Lactic acid bacteria are non pathogenic organism widely distributed in nature typically involved in a large number of spontaneous food fermentation. The purpose of this study was to characterize the bacteriocinogenic lactobacilli from fermented idli batter which can find application in biopreservation and biomedicine. Eight most promising lactobacilli were chosen from twenty two isolates based on their spectrum of activity against other lactic acid bacteria and pathogens. The eight lactobacil...

  1. Betaine Fermentation and Oxidation by Marine Desulfuromonas Strains

    OpenAIRE

    Heijthuijsen, J. H. F. G.; Hansen, T. A.

    1989-01-01

    Two bacterial strains were dominant in anaerobic enrichment cultures with betaine (N,N,N-trimethylglycine) as a substrate and intertidal mud as an inoculum. One was a coccoid bacterium which was a trimethylamine (TMA)-fermenting methanogen similar to Methanococcoides methylutens. The other strain, a rod-shaped, gram-negative, motile bacterium, fermented betaine. On the basis of its ability to oxidize acetate and ethanol to CO2 with sulfur as an electron acceptor, its inability to reduce sulfa...

  2. Ruminant meat as a raw material for fermented meat products

    OpenAIRE

    VOTAVA, Pavel

    2013-01-01

    The aim of this thesis was to obtain information on availability of ruminant meat, especially game, for the production of fermented meat products. The thesis provides an overview of different types of ruminants, whose meat is used in human nutrition. It summarizes the chemical composition of many species of domesticated meats or wildlife animals. The properties of these meats are discussed with regard to their use in the manufacture of fermented meat products, technology and factors affect...

  3. Microbiological Hydrogen Production by Anaerobic Fermentation and Photosynthetic Process

    Energy Technology Data Exchange (ETDEWEB)

    Asada, Y.; Ohsawa, M.; Nagai, Y.; Fukatsu, M.; Ishimi, K.; Ichi-ishi, S.

    2009-07-01

    Hydrogen gas is a clean and renewable energy carrier. Microbiological hydrogen production from glucose or starch by combination used of an anaerobic fermenter and a photosynthetic bacterium, Rhodobacter spheroides RV was studied. In 1984, the co-culture of Clostridium butyricum and RV strain to convert glucose to hydrogen was demonstrated by Miyake et al. Recently, we studied anaerobic fermentation of starch by a thermophilic archaea. (Author)

  4. Gas-liquid transfer of aroma compounds during winemaking fermentations

    OpenAIRE

    Mouret, Jean-Roch; Morakul, Sumallika; Nicolle, Pamela; Athes, Violaine; Sablayrolles, Jean-Marie

    2012-01-01

    We precisely monitored the production kinetics of 16 volatile carbon compounds corresponding to the predominant higher alcohols and esters produced during the alcoholic fermentation of wine using an online GC system. We studied the gas-liquid partitioning of isobutanol, isoamyl acetate and ethyl hexanoate and showed that CO2 stripping had no impact on the partition coefficient (k(i)). We formulated a predictive model for k(i) changes during the fermentation and calculated the gas-liquid balan...

  5. Selection of potential microorganism for sago starch fermentation

    OpenAIRE

    RUTH MELLIAWATI; ROHMATUSSOLIHAT; FERRA OCTAVINA

    2006-01-01

    Fermentation process of sago starch for the production of bioproduct requires potential microorganism that have ability to hydrolyze sago starch. The purpose of this research was to get the potential of amylolytic microorganisms for their capability of amyloglucosidase activity and to know the sugar strains of the fermentation result. Eleven amylolytic microorganisms (9 strains of mold and 2 strains of yeast) were obtained from the collection Research Centre for Biotechnology – Indonesian Ins...

  6. Biodiversity of Yeasts During Plum Wegierka Zwykla Spontaneous Fermentation

    OpenAIRE

    Satora, Pawel; Tuszynski, Tadeusz

    2005-01-01

    The study comprises an analysis of the yeast microbiota that participated in the spontaneous fermentation of crushed Wegierka Zwykla plum fruit, which is the raw material for slivovitz production in the mountain region in the south of Poland. Saccharomyces cerevisiae yeast strains were differentiated by means of the killer sensitivity analysis related to a killer reference panel of 9 well-known killer yeast strains. The first phase of the fermentation was dominated by the representatives of K...

  7. Fermenter studies on the production of pimaricin by streptomyces natalensis

    OpenAIRE

    Mahon, David

    1990-01-01

    The production of the polyene antibiotic, pimaricin by the organism Streptomyces natalensis CBS 700.57 was studied using an apparatus comprising a 10 litre fermentation vessel, and facilities for temperature, pH, dissolved oxygen, vessel pressure and gas composition measurement. The apparatus was connected via a Texas Instruments PM550 programmable logic controller to an IBM-compatible computer in order to record data from the fermentation and to control certain parameters. Adju...

  8. In vitro fermentation characteristics of corn and sorghum silages

    OpenAIRE

    Infascelli, F; V. Piccolo; A. Guglielmelli; M.I. Cutrignelli; F. Bovera; Grossi, M; R. Tudisco; S. Calabrò

    2010-01-01

    Aim of the study was to compare corn and sorghum forages, before and after ensiling, in terms of chemical-nutritional characteristics and fermentation kinetics, to substitute corn silage with sorghum silage. The trial was performed using sorghum (Sorghum vulgare) and corn (Zea mais) incubated in vitro at 39°C for 120 h with buffalo (Bubalus bubalis) rumen fluid. The in vitro gas production technique was used to describe the fermentation kinetics and to estimate the enery value of forages....

  9. Thiosulfate as a metabolic product: the bacterial fermentation of taurine

    OpenAIRE

    Denger, Karin; Laue, Heike; Cook, Alasdair M.

    1997-01-01

    Thiosulfate (S2O3²-) is a natural product that is widely utilized in natural ecosystems as an electron sink or as an electron donor. However, the major biological source(s) of this thiosulfate is unknown. We present the first report that taurine (2-aminoethanesulfonate), the major mammalian solute, is subject to fermentation. This bacterial fermentation was found to be catalyzed by a new isolate, strain GKNTAU, a strictly anaerobic, gram-positive, motile rod that formed subterminal spores. Th...

  10. Selection of lactic acid bacteria able to ferment inulin hydrolysates

    OpenAIRE

    Octavian BASTON; Oana Emilia CONSTANTIN

    2012-01-01

    Eight homofermentative lactic acid bacteria isolates were tested for lactic acid production using chicory and Jerusalem artichoke hydrolysate as substrate. The pH, lactic acid yield and productivity were used to select the best homolactic bacteria for lactic acid production. The selected strains produced lactic acid at maximum yield after 24 hours of fermentation and the productivity was greater at 24 hours of fermentation. From all studied strains, Lb1 and Lb2 showed the best results regardi...

  11. Biotechnology of indirect liquefaction: Progress report, April 1--June 30, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Datta, R.; Grethlein, H.; Jain, M.; Worden, M.; Zeikus, J.G.

    1988-01-01

    This project on indirect liquefaction of coal derived synthesis gas will focus on two stage anaerobic bioconversion. The first stage will address bioconversion of synthesis gas (CO, H/sub 2//CO/sub 2/) to volatile fatty acids by a CO adapted strain of Butyribacterium methylotrophicum. The second stage will address bioconversion of fatty acids to combustible solvents -- acetone butanol and ethanol by a strain of Clostridium acetobutylicum. The project began at MBI when the final contract was awarded on March 17, 1988. The initial tasks of the project are: Task la -- develop chemostat fermentation for syngas conversion by B. methylotrophicum and Task 2a -- produce biocatalysts (C. acetobutylicum) for second stage solvent-fuel synthesis. A multidisciplinary team of microbiologists and engineers has been put together to work on this project. Both tasks are progressing well. 5 refs., 4 figs., 1 tab.

  12. Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Progress report, December 1, 1978-February 28, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.I.C.; Cooney, C.L.; Demain, A.L.; Gomez, R.F.; Sinskey, A.J.

    1979-02-01

    The ongoing progress of a coordinated research program aimed at optimizing the biodegradation of cellulosic biomass to ethanol and chemical feedstocks is summarized. Growth requirements and genetic manipulations of clostridium thermocellum for selection of high cellulose producers are reported. The enzymatic activity of the cellulase produced by these organisms was studied. The soluble sugars produced from hydrolysis were analyzed. Increasing the tolerance of C. thermocellum to ethanol during liquid fuel production, increasing the rate of product formation, and directing the catabolism to selectively achieve high ethanol concentrations with respect to other products were studied. Alternative substrates for C. thermocellum were evaluated. Studies on the utilization of xylose were performed. Single stage fermentation of cellulose using mixed cultures of C. thermocellum and C. thermosaccharolyticum were studied. The study of the production of chemical feedstocks focused on acrylic acid, acetone/butanol, acetic acid, and lactic acid.

  13. LIGNOCELLULOSE AS AN ALTERNATIVE SOURCE FOR OBTAINING OF BIOBUTANOL

    Directory of Open Access Journals (Sweden)

    S. M. Shulga

    2013-04-01

    Full Text Available Energy and environmental crisis facing the world force us to reconsider the effectiveness or find an alternative use of renewable natural resources, especially organic «waste» by using environmentally friendly technologies. Microbial conversion of renewable resources of biosphere to produce useful products, including biofuels, currently is an actual biotech problem. Anaerobic bacteria of Clostridiaceae family are known as butanol producers, but unfortunately, the microbiological synthesis is currently not economical one. In order to make cost-effective aceton-butanol-ethanol fermentation, solventproducing strains using available cheap raw materials, such as agricultural waste or plant biomass, are required. Opportunities and ways to obtaine economic and ecological processing of lignocellulosic wastes for biobutanol creation are described in the review .

  14. Methanol contamination in traditionally fermented alcoholic beverages: the microbial dimension.

    Science.gov (United States)

    Ohimain, Elijah Ige

    2016-01-01

    Incidence of methanol contamination of traditionally fermented beverages is increasing globally resulting in the death of several persons. The source of methanol contamination has not been clearly established in most countries. While there were speculations that unscrupulous vendors might have deliberately spiked the beverages with methanol, it is more likely that the methanol might have been produced by contaminating microbes during traditional ethanol fermentation, which is often inoculated spontaneously by mixed microbes, with a potential to produce mixed alcohols. Methanol production in traditionally fermented beverages can be linked to the activities of pectinase producing yeast, fungi and bacteria. This study assessed some traditional fermented beverages and found that some beverages are prone to methanol contamination including cachaca, cholai, agave, arak, plum and grape wines. Possible microbial role in the production of methanol and other volatile congeners in these fermented beverages were discussed. The study concluded by suggesting that contaminated alcoholic beverages be converted for fuel use rather than out rightly banning the age-long traditional alcohol fermentation. PMID:27652180

  15. Chemical characterisation and application of acid whey in fermented milk.

    Science.gov (United States)

    Lievore, Paolla; Simões, Deise R S; Silva, Karolline M; Drunkler, Northon L; Barana, Ana C; Nogueira, Alessandro; Demiate, Ivo M

    2015-04-01

    Acid whey is a by-product from cheese processing that can be employed in beverage formulations due to its high nutritional quality. The objective of the present work was to study the physicochemical characterisation of acid whey from Petit Suisse-type cheese production and use this by-product in the formulation of fermented milk, substituting water. In addition, a reduction in the fermentation period was tested. Both the final product and the acid whey were analysed considering physicochemical determinations, and the fermented milk was evaluated by means of sensory analysis, including multiple comparison and acceptance tests, as well as purchase intention. The results of the physicochemical analyses showed that whey which was produced during both winter and summer presented higher values of protein (1.22 and 0.97 %, w/v, respectively), but there were no differences in lactose content. During the autumn, the highest solid extract was found in whey (6.00 %, w/v), with larger amounts of lactose (4.73 %, w/v) and ash (0.83 %, w/v). When analysing the fermented milk produced with added acid whey, the acceptance test resulted in 90 % of acceptance; the purchase intention showed that 54 % of the consumers would 'certainly buy' and 38 % would 'probably buy' the product. Using acid whey in a fermented milk formulation was technically viable, allowing by-product value aggregation, avoiding discharge, lowering water consumption and shortening the fermentation period. PMID:25829588

  16. Open and continuous fermentation: products, conditions and bioprocess economy.

    Science.gov (United States)

    Li, Teng; Chen, Xiang-bin; Chen, Jin-chun; Wu, Qiong; Chen, Guo-Qiang

    2014-12-01

    Microbial fermentation is the key to industrial biotechnology. Most fermentation processes are sensitive to microbial contamination and require an energy intensive sterilization process. The majority of microbial fermentations can only be conducted over a short period of time in a batch or fed-batch culture, further increasing energy consumption and process complexity, and these factors contribute to the high costs of bio-products. In an effort to make bio-products more economically competitive, increased attention has been paid to developing open (unsterile) and continuous processes. If well conducted, continuous fermentation processes will lead to the reduced cost of industrial bio-products. To achieve cost-efficient open and continuous fermentations, the feeding of raw materials and the removal of products must be conducted in a continuous manner without the risk of contamination, even under 'open' conditions. Factors such as the stability of the biological system as a whole during long cultivations, as well as the yield and productivity of the process, are also important. Microorganisms that grow under extreme conditions such as high or low pH, high osmotic pressure, and high or low temperature, as well as under conditions of mixed culturing, cell immobilization, and solid state cultivation, are of interest for developing open and continuous fermentation processes. PMID:25476917

  17. Fermented cassava waste and its utilization in broiler chickens rations

    Directory of Open Access Journals (Sweden)

    Supriyati

    2003-10-01

    Full Text Available Cassava waste is a by-product of cassava flour industry and its amount is increasing following the increasing of cassava flour industry. Its utilization as a feedstuff, is limited by its low protein content. The cassava waste is only utilized as the energy source. One of the alternative technology in improving the utilization of cassava waste as a feedstuff, by improving the nutritive value through fermentation process. Fermentation was carried out by solid substrate fermentation using Aspergillus niger as an inoculant and mixing with urea and ammonium sulphate as inorganic nitrogen sources. The nutritive value of the product was evaluated by feeding trial using 144 “Shaver Stabro” strain 3 days old chicks with 3 treatments i.e. 0 (control, 5.0 and 10.0% fermented cassava waste. The results showed that the true protein content of fermented cassava increased from 2.2 to 18.4%. The inclusion of fermented cassava waste up to 10% in chicken broiler ration for 4 weeks feeding did not affect the feed consumption, bodyweight gain, FCR, weight of liver and gibblets. All parameter results from 10% inclusion were not significantly different (P>0.05 with the control (0% inclusion.

  18. Betaine fermentation and oxidation by marine desulfuromonas strains.

    Science.gov (United States)

    Heijthuijsen, J H; Hansen, T A

    1989-04-01

    Two bacterial strains were dominant in anaerobic enrichment cultures with betaine (N,N,N-trimethylglycine) as a substrate and intertidal mud as an inoculum. One was a coccoid bacterium which was a trimethylamine (TMA)-fermenting methanogen similar to Methanococcoides methylutens. The other strain, a rod-shaped, gram-negative, motile bacterium, fermented betaine. On the basis of its ability to oxidize acetate and ethanol to CO(2) with sulfur as an electron acceptor, its inability to reduce sulfate and sulfite, its morphology, the presence of c-type cytochromes, and other characteristics, the isolated strain PM1 was identified as Desulfuromonas acetoxidans. Although only malate and fumarate were known as substrates for fermentative growth of this species, the type strain (DSM 684) also fermented betaine. Strain PM1 grew with a doubling time of 9.5 h at 30 degrees C on betaine and produced approximately 1 mol of TMA per mol of betaine, 0.75 mol of acetate, and presumably CO(2) as fermentation products but only in the presence of selenite (100 nM). In this fermentation, betaine is probably reductively cleaved to TMA and acetate, and part of the acetate is then oxidized to CO(2) to provide the reducing equivalents for the initial cleavage reaction. In the presence of sulfur, betaine was converted to TMA and presumably CO(2) with the formation of sulfide; then, only traces of acetate were produced. PMID:16347897

  19. Immunoreactivity, sensory and physicochemical properties of fermented soy protein isolate.

    Science.gov (United States)

    Meinlschmidt, Pia; Ueberham, Elke; Lehmann, Jörg; Schweiggert-Weisz, Ute; Eisner, P

    2016-08-15

    The effect of induced liquid state fermentation (Bacillus subtilis, Rhizopus oryzae, Saccharomyces cerevisiae, Lactobacillus helveticus) on the immunoreactivity, physicochemical and sensory properties of soy protein isolate (SPI) was studied. L. helveticus revealed the most abundant reduction in terms of immunoreactivity within soluble protein fractions, up to 100%, which could be measured by in vitro sandwich ELISA using mouse monoclonal anti-Glym5 antibodies (mAbs). Almost no binding was found in western blot analysis using mouse monoclonal mAbs and sera from soy sensitive individuals. Fermentation increased water- and oil-binding capacity as well as protein solubility at pH 4.0. Foaming activity was nearly doubled compared to non-fermented SPI. A decreased emulsifying capacity, foaming density, and quantity of soluble proteins at pH 7.0 were observed. Principal component analysis (PCA) confirmed decreased bitter and beany off-flavors of fermented samples compared to non-fermented SPI. Consequently, fermentation might be a promising method to produce tasty low-allergen food ingredients with good physicochemical properties. PMID:27006235

  20. Standard working procedures in production of traditionally fermented Sremska sausage

    Directory of Open Access Journals (Sweden)

    Vesković-Moračanin Slavica

    2011-01-01

    Full Text Available Investigations conducted within project "Techonological and protective characteristics of autochthonous strains of lactic acid bacteria isolated from traditional fermented sausages and possibilities for their implementation in the meat industry" (Project Number: 20127, financed on behalf of the Ministry for Science and Technology of the Republic of Serbia, have provided an answer on the characteristics of the quality of the used raw materials for the production of Sremska sausage - one of the most well-known Serbian traditionally fermented sausages (choice of meat, fatty tissue, additives and spices, and data have been registered in connection with the procedures of their processing, microclimatic conditions have been established (temperature, relative humidity, and air circulation during the entire process of production and fermentation, as well as the presence and types of microorganisms, primarily lactic acid bacteria (BMK, the carrier of lactic fermentation. The most important characteristics of the filling have been established, the smoking regimen, the regimens of fermentation, maturing, drying, as well as the parameters for quality and safety of the finished product. At the same time, the standard working procedure has been determined for the preparation of the meat, fatty tissue, the forming and inserting of the filling into the wrappers, as well as the characteristics of the finished products. The given standard working procedure should serve as a guideline for the meat industry in the production process of this traditional fermented sausage.

  1. Effects of Lactic Acid Bacteria Inoculated Fermentation on Pickled Cucumbers

    Directory of Open Access Journals (Sweden)

    Xiaoyi Ji

    2013-12-01

    Full Text Available The aim of this study was to determine the effects of Lactic Acid Bacteria (LAB fermentation on the texture and organic acid of pickled cucumbers. Texture and sensory evaluation as well as a microscopic observation were performed to study the textural differences among fresh cucumber, Spontaneous fermentation (SF cucumber and LAB Inoculating Fermentation (LABIF cucumber. Accumulation of seven organic acids i.e., oxalic, tartaric, malic, lactic, acetic, citric and succinic acid during cucumber pickling were also studied. The disruption extent of the middle lamella in SF cucumber displayed more obviously than that in LABIF cucumber, implying that LABIF contributed to keep the cucumber original structure intact. Based on the organic acid accumulation pattern, in SF LAB and Acetic Acid Bacteria (AAB fermented simultaneously, while in LABIF LAB fermented beforehand thus being in dominant position, then AAB fermented vigorously in a acidic condition created by LAB. The acetic acid accumulaton pattern could be regarded as the distinctive feature between SF and LABIF. The orgnic acids produced in LABIF were higher than that in SF. The final score of sensory evaluation combining texture analysis demonstrated that LABIF overmatched SF. It was concluded that LABIF could obviously enhance the quality of pickled cucumber and overwhelming SF, due to LABIF more beneficial to keep the cucumber original structure intact and organic acids accumulation.

  2. Invited review: Fermented milk as antihypertensive functional food.

    Science.gov (United States)

    Beltrán-Barrientos, L M; Hernández-Mendoza, A; Torres-Llanez, M J; González-Córdova, A F; Vallejo-Córdoba, B

    2016-06-01

    Over the past decade, interest has risen in fermented dairy foods that promote health and could prevent diseases such as hypertension. This biological effect has mainly been attributed to bioactive peptides encrypted within dairy proteins that can be released during fermentation with specific lactic acid bacteria or during gastrointestinal digestion. The most studied bioactive peptides derived from dairy proteins are antihypertensive peptides; however, a need exists to review the different studies dealing with the evaluation of antihypertensive fermented milk before a health claim may be associated with the product. Thus, the objective of this overview was to present available information related to the evaluation of fermented milk containing antihypertensive peptides by in vitro and in vivo studies, which are required before a fermented functional dairy product may be introduced to the market. Although commercial fermented milks with antihypertensive effects exist, these are scarce and most are based on Lactobacillus helveticus. Thus, a great opportunity is available for the development of functional dairy products with new lactic acid bacteria that support heart health through blood pressure- and heart rate-lowering effects. Hence, the consumer may be willing to pay a premium for foods with important functional benefits. PMID:26923047

  3. Effect of short-term sourdough fermentation on wheat protein

    Directory of Open Access Journals (Sweden)

    Raushid Ahmad Siddiqi

    2016-12-01

    Full Text Available Nowadays, baked goods are currently manufactured by accelerated processes. Under these circumstances, proteins are subjected to mild or no degradation during manufacturing. An effort was made to study effect of short-time sourdough fermentation on wheat protein. For this purpose, dough was prepared by mixing refined wheat flour with appropriate amount of water along with 20% curd, 2% yeast and 20% curd + 2% yeast followed by fermentation for 90 min at 37°C to study effect of fermentation. The moisture content of dough decreased with increase in fermentation time. The wet gluten content of dough inoculated with curd, yeast and curd + yeast was 27.01, 28.97 and 28.71%, respectively, and remained unaffected during fermentation. SDS-PAGE revealed that intensities of some of the higher molecular weight protein bands decreased in curd and curd + yeast treated dough. The colour parameters (L, a, b values remain almost unaltered with fermentation.

  4. Bioprocess Intensification of Beer Fermentation Using Immobilised Cells

    Science.gov (United States)

    Verbelen, Pieter J.; Nedović, Viktor A.; Manojlović, Verica; Delvaux, Freddy R.; Laskošek-Čukalović, Ida; Bugarski, Branko; Willaert, Ronnie

    Beer production with immobilised yeast has been the subject of research for approximately 30 years but has so far found limited application in the brewing industry, due to engineering problems, unrealised cost advantages, microbial contaminations and an unbalanced beer flavor (Linko et al. 1998; Brányik et al. 2005; Willaert and Nedović 2006). The ultimate aim of this research is the production of beer of desired quality within 1-3 days. Traditional beer fermentation systems use freely suspended yeast cells to ferment wort in an unstirred batch reactor. The primary fermentation takes approximately 7 days with a subsequent secondary fermentation (maturation) of several weeks. A batch culture system employing immobilization could benefit from an increased rate of fermentation. However, it appears that in terms of increasing productivity, a continuous fermentation system with immobilization would be the best method (Verbelen et al. 2006). An important issue of the research area is whether beer can be produced by immobilised yeast in continuous culture with the same characteristic as the traditional method.

  5. Effects of yeast, fermentation time, and preservation methods on tarhana.

    Science.gov (United States)

    Gurbuz, Ozan; Gocmen, Duygu; Ozmen, Nese; Dagdelen, Fatih

    2010-01-01

    The physicochemical properties of tarhana soup produced with different dough treatments, fermentation times, and preservation methods were examined. Tarhana doughs were prepared with yogurt (control) or baker's yeast (Saccharomyces cerevisiae) and fermented for 3 days. Samples were taken at 24, 48, and 72 hr. Samples were then preserved via one of four methods: sun dried, dried in the shade, vacumn dried, and frozen. Frozen samples produced lower organic acid levels after 72 hr of fermentation in both control (0.68 g/100 g) and yeast (0.61 g/100 g) applications than samples that were dried (0.94 g/100 g control samples; 0.81 g/100 g samples with yeast). Increasing fermentation time resulted in a significant effect on the formation of organic acid in the tarhana (p .01). However, sensory scores for tarhana prepared from the samples dried in a sheltered area showed a reduction in color desireablilty as the fermentation time increased. The soup prepared from frozen tarhana (72 hr fermentation, with yeast) had the highest scores with respect to color, mouth feel, flavor, and overall acceptability. Vacuum-dried samples' scores in these areas were also high in comparison to the two other drying methods. PMID:21108130

  6. Effect of Propanoic Acid on Ethanol Fermentation by Saccharomyces cerevisiae in an Ethanol-Methane Coupled Fermentation Process

    Institute of Scientific and Technical Information of China (English)

    张成明; 杜风光; 王欣; 毛忠贵; 孙沛勇; 唐蕾; 张建军

    2012-01-01

    Propanoic acid accumulated in an ethanol-methane coupled fermentation process affects the ethanol fermentation by Saccharomyces cerevisiae. The effects of propanoic acid on ethanol production were examined in cassava mash under different pH conditions. Final ethanol concentrations increased when undissociated propanoic acid was 〈30.0 mmol·L-1 . Propanoic acid, however, stimulated ethanol production, as much as 7.6% under proper conditions, but ethanol fermentation was completely inhibited when undissociated acid was 〉53.2 mmol·L-1 . Therefore, the potential inhibitory effect of propanoic acid on ethanol fermentation may be avoided by controlling the undissociated acid concentrations through elevated medium pH. Biomass and glycerol production decreased with propanoic acid in the medium, partly contributing to increased ethanol concentration.

  7. Fermentation temperature and wort composition influence on diacetyl and 2, 3-pentanedione contents in beer

    Directory of Open Access Journals (Sweden)

    Pejin Jelena D.

    2005-01-01

    Full Text Available Diacetyl and 2,3-pentanedione are important constituents of beer sensory properties. A new GC/MS method for diacetyl and 2,3-pentanedione content determination was developed. This method was applied for the determination of diacetyl and 2,3-pentanedione contents during beer fermentation (primary fermentation and maturation. Primary fermentations were carried out at different temperatures (8°C and 14°C. Primary fermentation temperature had a great influence on diacetyl and 2,3-pentanedione formation and reduction. Formation and reduction rates increased with the primary fermentation temperature increasment. Diacetyl and 2,3-pentanedione contents also increased with the corn grits increasment. Fermentations were carried out with Saccharomyces cerevisiae pure culture, specially prepared for each fermentation. This GC/MS method for diacetyl and 2,3-pentanedione determination was valuable for analysing the influence of wort composition or fermentation conditions such as primary fermentation temperature on their formation and reduction.

  8. Inoculated fermentation of green olives with potential probiotic Lactobacillus pentosus and Lactobacillus plantarum starter cultures isolated from industrially fermented olives.

    Science.gov (United States)

    Blana, Vasiliki A; Grounta, Athena; Tassou, Chrysoula C; Nychas, George-John E; Panagou, Efstathios Z

    2014-04-01

    The performance of two strains of lactic acid bacteria (LAB), namely Lactobacillus pentosus B281 and Lactobacillus plantarum B282, previously isolated from industrially fermented table olives and screened in vitro for probiotic potential, was investigated as starter cultures in Spanish style fermentation of cv. Halkidiki green olives. Fermentation was undertaken at room temperature in two different initial salt concentrations (8% and 10%, w/v, NaCl) in the brines. The strains were inoculated as single and combined cultures and the dynamics of their population on the surface of olives was monitored for a period of 114 days. The survival of inoculated strains on olives was determined using Pulsed Field Gel Electrophoresis (PFGE). Both probiotic strains successfully colonized the olive surface at populations ranged from 6.0 to 7.0 log CFU/g throughout fermentation. PFGE analysis revealed that L. pentosus B281 presented higher colonization in both salt levels at the end of fermentation (81.2% and 93.3% in 8% and 10% NaCl brines, respectively). For L. plantarum B282 a high survival rate (83.3%) was observed in 8% NaCl brines, but in 10% NaCl the strain could not colonize the surface of olives. L. pentosus B281 also dominated over L. plantarum B282 in inoculated fermentations when the two strains were used as combined culture. The biochemical profile (pH, organic acids, volatile compounds) attained during fermentation and the sensory analysis of the final product indicated a typical lactic acid fermentation process of green olives.

  9. Biohydrogen production from combined dark-photo fermentation under a high ammonia content in the dark fermentation effluent

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chun-Yen [National Cheng Kung Univ., Tainan, Taiwan (China). Dept. of Chemical Engineering; National Cheng Kung Univ., Tainan, Taiwan (China). Sustainable Environment Research Center; Lo, Yung-Chung; Yeh, Kuei-Ling [National Cheng Kung Univ., Tainan, Taiwan (China). Dept. of Chemical Engineering; Chang, Jo-Shu [National Cheng Kung Univ., Tainan, Taiwan (China). Dept. of Chemical Engineering; National Cheng Kung Univ., Tainan, Taiwan (China). Sustainable Environment Research Center; National Cheng Kung Univ., Tainan, Taiwan (China). Microalgae Biotechnology and Bioengineering Lab.

    2010-07-01

    Integrated dark and photo (two-stage) fermentation was employed to enhance the performance of H{sub 2} production. First, the continuous dark fermentation using indigenous Clostridium butyricum CGS5 was carried out at 12 h HRT and fed with sucrose at a concentration of 18750 mg/l. The overall H{sub 2} production rate and H{sub 2} yield were fairly stable with a mean value of 87.5 ml/l/h and 1.015 mol H{sub 2}/mol sucrose, respectively. In addition, a relatively high ammonia nitrogen content (574 mg/l) in the dark fermentation effluent was observed. The soluble metabolites from dark fermentation, consisting mainly of butyric, lactic and acetic acids, were directly used as the influent of continuous photo-H{sub 2} production process inoculated with Rhodopseudomonas palutris WP 3-5 under the condition of 35oC, 10000 lux irradiation, pH 7.0 and 48 h HRT. The maximum overall hydrogen production rate from photo fermentation was 16.4 ml H{sub 2}/l/h, and the utilization of the soluble metabolites could reach 90%. The maximum H{sub 2} yield dramatically increased from 1.015 mol H{sub 2}/mol sucrose (in dark fermentation only) to 6.04 mol H{sub 2}/mol sucrose in the combined dark and photo fermentation. Surprisingly, the operation strategy applied in this work was able to attain an average NH{sub 3}-N removal efficiency of 92%, implying that our photo-H{sub 2} production system has a higher NH{sub 3}-N tolerance, demonstrating its high applicability in an integrated dark-photo fermentation system. (orig.)

  10. Effect of acetic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

    Science.gov (United States)

    Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2014-09-01

    An integrated citric acid-methane fermentation process was proposed to solve the problem of extraction wastewater in citric acid fermentation process. Extraction wastewater was treated by anaerobic digestion and then recycled for the next batch of citric acid fermentation to eliminate wastewater discharge and reduce water resource consumption. Acetic acid as an intermediate product of methane fermentation was present in anaerobic digestion effluent. In this study, the effect of acetic acid on citric acid fermentation was investigated and results showed that lower concentration of acetic acid could promote Aspergillus niger growth and citric acid production. 5-Cyano-2,3-ditolyl tetrazolium chloride (CTC) staining was used to quantify the activity of A. niger cells, and the results suggested that when acetic acid concentration was above 8 mM at initial pH 4.5, the morphology of A. niger became uneven and the part of the cells' activity was significantly reduced, thereby resulting in deceasing of citric acid production. Effects of acetic acid on citric acid fermentation, as influenced by initial pH and cell number in inocula, were also examined. The result indicated that inhibition by acetic acid increased as initial pH declined and was rarely influenced by cell number in inocula.

  11. Effect of propionic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

    Science.gov (United States)

    Xu, Jian; Bao, Jia-Wei; Su, Xian-Feng; Zhang, Hong-Jian; Zeng, Xin; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2016-03-01

    In this study, an integrated citric acid-methane fermentation process was established to solve the problem of wastewater treatment in citric acid production. Citric acid wastewater was treated through anaerobic digestion and then the anaerobic digestion effluent (ADE) was further treated and recycled for the next batch citric acid fermentation. This process could eliminate wastewater discharge and reduce water resource consumption. Propionic acid was found in the ADE and its concentration continually increased in recycling. Effect of propionic acid on citric acid fermentation was investigated, and results indicated that influence of propionic acid on citric acid fermentation was contributed to the undissociated form. Citric acid fermentation was inhibited when the concentration of propionic acid was above 2, 4, and 6 mM in initial pH 4.0, 4.5 and, 5.0, respectively. However, low concentration of propionic acid could promote isomaltase activity which converted more isomaltose to available sugar, thereby increasing citric acid production. High concentration of propionic acid could influence the vitality of cell and prolong the lag phase, causing large amount of glucose still remaining in medium at the end of fermentation and decreasing citric acid production.

  12. Revisiting Neoclassical Growth Theory: A Survey in the Literature

    Directory of Open Access Journals (Sweden)

    Mayank GUPTA

    2015-03-01

    Full Text Available Abstract During the second half of the twentieth century economists have build newer models of economic growth that consider policy influences of growth and divergent outcomes among countries. These models addresses issues concerning economic growth, operation of financial markets, trade policy, government expenditures, and taxation. In this essay we have revisited the interdependence of political and economic institutions, taking the neoclassical growth model of Solow (1956 as a point of departure, which maintains that long run economic growth can be explained by capital accumulation, population growth and technological progress. We first discuss the evolution of the neoclassical school of economics in a historical context, and the role of various institutions in engendering economic growth. Subsequently the role of government spending, political stability, property rights and special interest groups (SIG's affect economic growth have been discussed, and how these institutions can explain different countries to grow at divergent rates and achieve different levels of wealth.

  13. Semiclassical approach for the evaporating black hole revisited

    Science.gov (United States)

    Gim, Yongwan; Kim, Wontae

    2016-01-01

    A recent calculation shows that the observed energy density in the Unruh state at the future event horizon as seen by a freely falling observer is finite if the observer is released from rest at any positive distance outside the horizon; however, it is getting larger and larger so that it is negatively divergent at the horizon in the limit that the observer starts falling from rest at the horizon, which corresponds to the infinite boost with respect to the freely falling observer at a finite distance from the horizon. In order to resolve some conflicts between the recent calculation and the conventional ones in the well-known literatures, the calculation of the free-fall energy density is revisited and some differences are pointed out.

  14. Revisiting manufacturing strategy: contributions towards a new construct

    Directory of Open Access Journals (Sweden)

    Eliciane Maria da Silva

    2008-07-01

    Full Text Available This paper aims at revisiting and systematizing the literature on manufacturing strategy. Although this is a well consolidated theme broadly discussed in the last fifty years, manufacturing strategy practice grew on importance recently due to a more competitive environment the companies find themselves in. The review carried has systematized the existing literature into six lines of research dealing with competitive priorities, structural and infrastructural decision, best practices, performance indicators, production strategy formulation and generic manufacturing strategies. This article shows that four out of the six research areas are still receiving attention. A new construct which represents a global view of the lines of research mentioned is proposed. Gaps in the research field and suggestions for future works are described. Keywords: manufacturing strategy, content, formulation of manufacturing strategy, competitive priorities, best practices, performance indicators.

  15. Serotype-specific mortality from invasive Streptococcus pneumoniae disease revisited

    DEFF Research Database (Denmark)

    Martens, Pernille; Worm, Signe Westring; Lundgren, Bettina;

    2004-01-01

    Serotype-specific mortality from invasive Streptococcus pneumoniae disease revisited.Martens P, Worm SW, Lundgren B, Konradsen HB, Benfield T. Department of Infectious Diseases 144, Hvidovre University Hospital, DK-2650 Hvidovre, Denmark. pernillemartens@yahoo.com BACKGROUND: Invasive infection...... with Streptococcus pneumoniae (pneumococci) causes significant morbidity and mortality. Case series and experimental data have shown that the capsular serotype is involved in the pathogenesis and a determinant of disease outcome. METHODS: Retrospective review of 464 cases of invasive disease among adults diagnosed...... with serotype 1 was associated with a decreased risk of death (RR 0.23 (95% CI, 0.06-0.97)). Additionally, older age, relative leucopenia and relative hypothermia were independent predictors of mortality. CONCLUSION: Our study shows that capsular serotypes independently influenced the outcome from invasive...

  16. Energy in synthetic fertilizers and pesticides: Revisited. Final project report

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, M.G.; English, B.C.; Turhollow, A.F.; Nyangito, H.O. [Tennessee Univ., Knoxville, TN (United States). Dept. of Agricultural Economics and Rural Sociology

    1994-01-01

    Agricultural chemicals that are derived from fossil-fuels are the major energy intensive inputs in agriculture. Growing scarcity of the world`s fossil resources stimulated research and development of energy-efficient technology for manufacturing these chemicals in the last decade. The purpose of this study is to revisit the energy requirements of major plant nutrients and pesticides. The data from manufacturers energy survey conducted by The Fertilizer Institute are used to estimate energy requirements of fertilizers. Energy estimates for pesticides are developed from consulting previously published literature. The impact of technical innovation in the fertilizer industry to US corn, cotton, soybean and wheat producers is estimated in terms of energy-saving.

  17. Global Instability on Laminar Separation Bubbles-Revisited

    Science.gov (United States)

    Theofilis, Vassilis; Rodriquez, Daniel; Smith, Douglas

    2010-01-01

    In the last 3 years, global linear instability of LSB has been revisited, using state-of-the-art hardware and algorithms. Eigenspectra of LSB flows have been understood and classified in branches of known and newly-discovered eigenmodes. Major achievements: World-largest numerical solutions of global eigenvalue problems are routinely performed. Key aerodynamic phenomena have been explained via critical point theory, applied to our global mode results. Theoretical foundation for control of LSB flows has been laid. Global mode of LSB at the origin of observable phenomena. U-separation on semi-infinite plate. Stall cells on (stalled) airfoil. Receptivity/Sensitivity/AFC feasible (practical?) via: Adjoint EVP solution. Direct/adjoint coupling (the Crete connection). Minor effect of compressibility on global instability in the subsonic compressible regime. Global instability analysis of LSB in realistic supersonic flows apparently quite some way down the horizon.

  18. Impulsive Spot Heating and Thermal Explosion of Interstellar Grains Revisited

    CERN Document Server

    Ivlev, A V; Vasyunin, A; Caselli, P

    2015-01-01

    The problem of impulsive heating of dust grains in cold, dense interstellar clouds is revisited theoretically, with the aim to better understand leading mechanisms of the explosive desorption of icy mantles. It is rigorously shown that if the heating of a reactive medium occurs within a sufficiently localized spot (e.g., heating of mantles by cosmic rays), then the subsequent thermal evolution is characterized by a single dimensionless number $\\lambda$. This number identifies a bifurcation between two distinct regimes: When $\\lambda$ exceeds a critical value (threshold), the heat equation exhibits the explosive solution, i.e., the thermal (chemical) explosion is triggered. Otherwise, thermal diffusion causes the deposited heat to spread over the entire grain -- this regime is commonly known as the whole-grain heating. The theory allows us to find a critical combination of the physical parameters that govern the explosion of icy mantles due to impulsive spot heating. In particular, the calculations suggest tha...

  19. Neuroticism and vigilance revisited: A transcranial doppler investigation.

    Science.gov (United States)

    Mandell, Arielle R; Becker, Alexandra; VanAndel, Aaron; Nelson, Andrew; Shaw, Tyler H

    2015-11-01

    Selecting for vigilance assignments remains an important factor in human performance research. The current study revisits the potential relationship between vigilance performance and trait neuroticism, in light of two possible theories. The first theory suggests that neuroticism impairs vigilance performance by competing for available resources. The second theory, attentional control theory, posits that high neuroticism can result in similar or superior performance levels due to the allocation of compensatory effort. In the present study, Transcranial Doppler Sonography was used to investigate the neurophysiological underpinnings of neuroticism during a 12-min abbreviated vigilance task. Performance results were not modified by level of neuroticism, but high neuroticism was associated with higher initial CBFV levels and a greater CBFV decrement over time. These findings indicate that participants higher in neuroticism recruited additional cognitive resources in order to achieve similar performance, suggesting that there is more of an effect on processing efficiency than effectiveness.

  20. Revisiting constraints on uplifts to de Sitter vacua

    CERN Document Server

    Bizet, Nana Cabo

    2016-01-01

    We revisit the issue of uplifting the potential to de Sitter (dS) vacua in type IIB flux compactifications of Kachru, Kallosh, Linde and Trivedi (KKLT). We shed light on some tension between two constraints on dS vacua in type IIB string theory. One is the well-known and much-discussed constraint which leads to the no-go theorem that can in principle be evaded. The other follows from 4-dimensional Einstein's equations, which has, however, been much less discussed in connection with the former constraint. In addition to the challenges previously posed, it is suggested that the uplifting scenarios, in particular, obstruct the evasion of the no-go theorem more strongly than one might have assumed.