Enzymatic saccharification of seaweeds into fermentable sugars by xylanase from marine Bacillus sp. strain BT21.

Science.gov (United States)

Parab, Pankaj; Khandeparker, Rakhee; Amberkar, Ujwala; Khodse, Vishwas

2017-10-01

Enzymatic hydrolysis of seaweed biomass was studied using xylanase produced from marine bacteria Bacillus sp. strain BT21 through solid-state fermentation of wheat bran. Three types of seaweeds, Ahnfeltia plicata , Padina tetrastromatica and Ulva lactuca , were selected as representatives of red, brown, and green seaweeds, respectively. Seaweed biomass was pretreated with hot water. The efficiency of pretreated biomass to release reducing sugar by the action of xylanase as well as the type of monosaccharide released during enzyme saccharification of seaweed biomass was studied. It was seen that pretreated biomass of seaweed A. plicata, U. lactuca , and P. tetrastroma , at 121 °C for 45 min, followed by incubation with 50 IU xylanase released reducing sugars of 233 ± 5.3, 100 ± 6.1 and 73.3 ± 4.1 µg/mg of seaweed biomass, respectively. Gas chromatography analysis illustrated the release of xylose, glucose, and mannose during the treatment process. Hot water pre-treatment process enhanced enzymatic conversion of biomass into sugars. This study revealed the important role of xylanase in saccharification of seaweed, a promising feedstock for third-generation bioethanol production.

Increasing fermentation efficiency at high sugar concentrations by supplementing an additional source of nitrogen during the exponential phase of the tequila fermentation process.

Science.gov (United States)

Arrizon, Javier; Gschaedler, Anne

2002-11-01

In the tequila industry, fermentation is traditionally achieved at sugar concentrations ranging from 50 to 100 g x L(-1). In this work, the behaviour of the Saccharomyces cerevisiae yeast (isolated from the juices of the Agave tequilana Weber blue variety) during the agave juice fermentation is compared at different sugar concentrations to determine if it is feasible for the industry to run fermentation at higher sugar concentrations. Fermentation efficiency is shown to be higher (above 90%) at a high concentration of initial sugar (170 g x L(-1)) when an additional source of nitrogen (a mixture of amino acids and ammonium sulphate, different than a grape must nitrogen composition) is added during the exponential growth phase.

Fermentation of sugar solutions to butanol, acetone, and ethanol

Energy Technology Data Exchange (ETDEWEB)

Karsch, W; Schoeder, K

1956-04-05

The fermentation process takes place with participation of BuOH bacteria. A favorable content of AcOH (0.1 to 0.4%) is achieved by distillation with steam, by mixing fermentable liquids of different AcOH contents, or by precipitation of excess AcOH as salts insoluble in water before the fermentation process itself. Thus, a total yield about 40% organic solvents based on the reduced sugar is obtained, i.e., 10 to 20% more than previously obtained.

COMPARISON OF PRETREATMENT STRATEGIES FOR CONVERSION OF COCONUT HUSK FIBER TO FERMENTABLE SUGARS

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Teck Y. Ding,

2012-02-01

Full Text Available In the present study, coconut husk was employed as biomass feedstock for production of bioethanol, due to its abundance in Malaysia. Due to the complex structures of coconut husk, a pretreatment process is crucial in extracting fermentable sugars from the embedded cellulose matrix for subsequent ethanol fermentation process. The ground coconut husk was subjected to three different pretreatment processes inclusive of thermal, chemical, and microwave-assisted-alkaline techniques, prior to enzymatic hydrolysis and fermentation process. The composition profile of coconut husk was significantly altered upon the microwave-assisted-alkaline treatment as compared to the untreated sample, with the cellulose content increasing from 18-21% to 38-39% while lignin content decreased from 46-53% to 31-33%. Among the pretreatment methods applied, enzymatic hydrolysis of coconut husk pretreated by microwave-assisted-alkaline method recorded the highest yield of fermentable sugars, 0.279 g sugar/g substrate. SEM imaging showed the obvious and significant disruption of coconut husks’ structure after microwave-assisted-alkaline pretreatment. In conclusion, by employing suitable pretreatment technique in treating the lignocellulosic materials of coconut husk, the extracted fermentable sugar is a potential substrate for bioethanol production.

Ethanol and sugar tolerance of wine yeasts isolated from fermenting ...

African Journals Online (AJOL)

Seventeen wine yeasts isolated from fermenting cashew apple juice were screened for ethanol and sugar tolerance. Two species of Saccharomyces comprising of three strains of S. cerevisiae and one S. uvarum showed measurable growth in medium containing 9% (v/v) ethanol. They were equally sugar-tolerant having ...

Conversion of woody biomass into fermentable sugars by cellulase from Agaricus arvensis.

Science.gov (United States)

Jeya, Marimuthu; Nguyen, Ngoc-Phuong-Thao; Moon, Hee-Jung; Kim, Sang-Hwan; Lee, Jung-Kul

2010-11-01

Agaricus arvensis, a newly isolated basidiomycetous fungus, was found to secrete efficient cellulases. The strain produced the highest endoglucanase (EG), cellobiohydrolase (CBH) and beta-glucosidase (BGL) activities of 0.3, 3.2 and 8U/mg-protein, respectively, with rice straw as the carbon source. Saccharification of the woody biomass with A. arvensis cellulase as the enzyme source released a high level of fermentable sugars. Enzymatic hydrolysis of the poplar biomass was optimized using the response surface methodology in order to study the influence of the variables (pH, temperature, cellulases concentration and substrate concentration). The enzyme and substrate concentrations were identified as the limiting factors for the saccharification of poplar wood biomass. A total reducing sugar level of 29g/L (293mg/g-substrate) was obtained at an enzyme concentration of 65FPU/g-substrate after optimization of the hydrolysis parameters. The model validation showed a good agreement between the experimental results and the predicted responses. A. arvensis could be a good candidate for the production of reducing sugars from a cellulosic biomass.

Economics of alcohol manufacture by fermentation of cane-sugar molasses

Energy Technology Data Exchange (ETDEWEB)

Narasimhe, I

1964-01-01

An improved continuous fermentation technique consists of using a special strain of yeast, GN/1942-2 (C), having high attenuating power and high alcohol tolerance which can function efficiently in the higher concentrations of sugars necessary to produce a mash containing 10 to 12% alcohol. The yeast is fed with suitable nutrients in the pre-fermentors at a regulated rate to maintain a constant cell population at all stages, thus enhancing the speed of fermentation. Thus, double the normal quantity of molasses can be fermented without sacrificing the efficiency of fermentation.

Economics of alcohol manufacture by fermentation of cane-sugar molasses

Energy Technology Data Exchange (ETDEWEB)

Narasimha, I

1964-01-01

An improved continuous fermentation technique consists of using a special strain of yeast, GN/1942-2 (C), having high attenuating power and high alcohol tolerance which can function efficiently in the higher concentrations of sugars necessary to produce a mash containing 10 to 12% alcohol. The yeast is fed with suitable nutrients in the prefermentors at a regulated rate to maintain a constant cell population at all stages, thus enhancing the speed of fermentation. Thus, double the normal quantity of molasses can be fermented without sacrificing the efficiency of fermentation.

Enzymatically-Mediated Co-Production of Cellulose Nanocrystals and Fermentable Sugars

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Dawit Beyene

2017-10-01

Full Text Available Cellulose nanocrystals (CNCs can be extracted from cellulosic materials through the degradation of non-crystalline cellulose domains in the feedstock via acid hydrolysis. However, the sugars released from the hydrolysis process cannot be easily recovered from the acid waste stream. In this study, cellulases were used to preferentially degrade non-crystalline domains with the objectives of recovering sugars and generating a feedstock with concentrated CNC precursors for a more efficient acid hydrolysis process. Filter paper and wood pulp substrates were enzyme-treated for 2–10 h to recover 20–40 wt % glucose. Substantial xylose yield (6–12 wt % was generated from wood pulp. CNC yields from acid hydrolysis of cellulases-treated filter paper, and wood pulp improved by 8–18% and 58–86%, respectively, when compared with the original substrate. It was thought that CNC precursors accumulated in the cellulases-treated feedstock due to enzymatic digestion of the more accessible non-crystalline celluloses. Therefore, acid hydrolysis from enzyme-treated feedstock will require proportionally less water and reagents resulting in increased efficiency and productivity in downstream processes. This study demonstrates that an enzymatically-mediated process allows recovery of fermentable sugars and improves acid hydrolysis efficiency for CNC production.

Ethanol fermentation of molasses by Saccharomyces cerevisiae cells immobilized onto sugar beet pulp

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Vučurović Vesna M.

2012-01-01

Full Text Available Natural adhesion of Saccharomyces cerevisiae onto sugar beet pulp (SBP is a very simple and cheap immobilization method for retaining high cells density in the ethanol fermentation system. In the present study, yeast cells were immobilized by adhesion onto SBP suspended in the synthetic culture media under different conditions such as: glucose concentration (100, 120 and 150 g/l, inoculum concentration (5, 10 and 15 g/l dry mass and temperature (25, 30, 35 and 40°C. In order to estimate the optimal immobilization conditions the yeast cells retention (R, after each immobilization experiment was analyzed. The highest R value of 0.486 g dry mass yeast /g dry mass SBP was obtained at 30°C, glucose concentration of 150 g/l, and inoculum concentration of 15 g/l. The yeast immobilized under these conditions was used for ethanol fermentation of sugar beet molasses containing 150.2 g/l of reducing sugar. Efficient ethanol fermentation (ethanol concentration of 70.57 g/l, fermentation efficiency 93.98% of sugar beet molasses was achieved using S. cerevisiae immobilized by natural adhesion on SBP. [Projekat Ministarstva nauke Republike Srbije, br. TR-31002

Sugaring-out extraction of acetoin from fermentation broth by coupling with fermentation.

Science.gov (United States)

Dai, Jian-Ying; Ma, Lin-Hui; Wang, Zhuang-Fei; Guan, Wen-Tian; Xiu, Zhi-Long

2017-03-01

Acetoin is a natural flavor and an important bio-based chemical which could be separated from fermentation broth by solvent extraction, salting-out extraction or recovered in the form of derivatives. In this work, a novel method named as sugaring-out extraction coupled with fermentation was tried in the acetoin production by Bacillus subtilis DL01. The effects of six solvents on bacterial growth and the distribution of acetoin and glucose in different solvent-glucose systems were explored. The operation parameters such as standing time, glucose concentration, and volume ratio of ethyl acetate to fermentation broth were determined. In a system composed of fermentation broth, glucose (100%, m/v) and two-fold volume of ethyl acetate, nearly 100% glucose was distributed into bottom phase, and 61.2% acetoin into top phase without coloring matters and organic acids. The top phase was treated by vacuum distillation to remove solvent and purify acetoin, while the bottom phase was used as carbon source to produce acetoin in the next batch of fermentation.

Pretreatment and hydrolysis methods for recovery of fermentable sugars from de-oiled Jatropha waste.

Science.gov (United States)

Kumar, Gopalakrishnan; Sen, Biswarup; Lin, Chiu-Yue

2013-10-01

The release of reducing sugars (RS) upon various pretreatments and hydrolysis methods from de-oiled Jatropha waste (DJW) was studied. The highest RS concentration of 12.9 g/L was observed at 10% enzyme hydrolysis. The next highest RS of 8.0 g/L and 7.8 g/L were obtained with 10% HCl and 2.5% H2SO4, respectively. The NaOH (2.5%), ultrasonication and heat (90°C for 60 min) treatments showed the RS concentration of 2.5 g/L, 1.1 g/L and 2.0 g/L, respectively. Autoclave treatment slightly enhanced the sugar release (0.9 g/L) compared to no treatment (0.7 g/L). Glucose release (11.4 g/L) peaked in enzyme hydrolysis. Enzyme treated acid unhydrolysed biomass showed 11.1 g/L RS. HCl and H2SO4 pretreatment gave maximal xylose (6.89 g/L and 6.16 g/L, respectively). Combined (acid and enzyme) hydrolysis employed was efficient and its subsequent batch hydrogen fermentation showed a production 3.1 L H2/L reactor. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fermentation of biomass sugars to ethanol using native industrial yeast strains.

Science.gov (United States)

Yuan, Dawei; Rao, Kripa; Relue, Patricia; Varanasi, Sasidhar

2011-02-01

In this paper, the feasibility of a technology for fermenting sugar mixtures representative of cellulosic biomass hydrolyzates with native industrial yeast strains is demonstrated. This paper explores the isomerization of xylose to xylulose using a bi-layered enzyme pellet system capable of sustaining a micro-environmental pH gradient. This ability allows for considerable flexibility in conducting the isomerization and fermentation steps. With this method, the isomerization and fermentation could be conducted sequentially, in fed-batch, or simultaneously to maximize utilization of both C5 and C6 sugars and ethanol yield. This system takes advantage of a pH-dependent complexation of xylulose with a supplemented additive to achieve up to 86% isomerization of xylose at fermentation conditions. Commercially-proven Saccharomyces cerevisiae strains from the corn-ethanol industry were used and shown to be very effective in implementation of the technology for ethanol production. Copyright © 2010 Elsevier Ltd. All rights reserved.

Separation, hydrolysis and fermentation of pyrolytic sugars to produce ethanol and lipids.

Science.gov (United States)

Lian, Jieni; Chen, Shulin; Zhou, Shuai; Wang, Zhouhong; O'Fallon, James; Li, Chun-Zhu; Garcia-Perez, Manuel

2010-12-01

This paper describes a new scheme to convert anhydrosugars found in pyrolysis oils into ethanol and lipids. Pyrolytic sugars were separated from phenols by solvent extraction and were hydrolyzed into glucose using sulfuric acid as a catalyst. Toxicological studies showed that phenols and acids were the main species inhibiting growth of the yeast Saccharomyces cerevisiae. The sulfuric acids, and carboxylic acids from the bio-oils, were neutralized with Ba(OH)(2). The phase rich in sugar was further detoxified with activated carbon. The resulting aqueous phase rich in glucose was fermented with three different yeasts: S. cerevisiae to produce ethanol, and Cryptococcus curvatus and Rhodotorula glutinis to produce lipids. Yields as high as 0.473 g ethanol/g glucose and 0.167 g lipids/g sugar (0.266 g ethanol equivalent/g sugar), were obtained. These results confirm that pyrolytic sugar fermentation to produce ethanol is more efficient than for lipid production. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Influence of physiological state of inoculum on volatile acidity production by Saccharomyces cerevisiae during high sugar fermentation

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Marina Bely

2005-12-01

Full Text Available An approach consisting of controlling yeast inoculum to minimize volatile acidity production by Saccharomyces cerevisiae during the alcoholic fermentation of botrytized must was investigated. Direct inoculation of rehydrated active dry yeasts produced the most volatile acidity, while a yeast preparation pre-cultured for 24 hours reduced the final production by up to 23 %. Using yeasts collected from a fermenting wine as a starter must also reduced volatile acidity production. The conditions for preparing the inoculum affected the fermentation capacity of the first generation yeasts: fermentation duration, sugar to ethanol ratio, and wine composition. A pre-culture medium with a low sugar concentration (< 220 g/L is essential to limit volatile acidity production in high sugar fermentations.

Fermentation behaviour and volatile compound production by agave and grape must yeasts in high sugar Agave tequilana and grape must fermentations.

Science.gov (United States)

Arrizon, Javier; Fiore, Concetta; Acosta, Guillermina; Romano, Patrizia; Gschaedler, Anne

2006-01-01

Few studies have been performed on the characterization of yeasts involved in the production of agave distilled beverages and their individual fermentation properties. In this study, a comparison and evaluation of yeasts of different origins in the tequila and wine industries were carried out for technological traits. Fermentations were carried out in high (300 g l(-1)) and low (30 g l(-1)) sugar concentrations of Agave tequilana juice, in musts obtained from Fiano (white) and Aglianico (red) grapes and in YPD medium (with 270 g l(-1) of glucose added) as a control. Grape yeasts exhibited a reduced performance in high-sugar agave fermentation, while both agave and grape yeasts showed similar fermentation behaviour in grape musts. Production levels of volatile compounds by grape and agave yeasts differed in both fermentations.

Alcoholic fermentation by immobilized yeast at high sugar concentrations

Energy Technology Data Exchange (ETDEWEB)

Holcberg, I.B.; Margalith, P.

1981-01-01

Glucose fermentation by Saccharomyces cerevisiae immobilized by entrapment in agar, carrageenan, alginate and polyacrylamide gels, was compared to that of freely suspended cells at concentration of 10-50% (w.w.) sugar. The rate of ethanol production by the entrapped cells was 20-25% higher than that of the free cells. Concentrations of up to 14.5% w/w ethanol (30% glucose initial concentration) could be obtained. A number of hypotheses for the improved alcoholic fermentation are discussed.

Overliming detoxification of pyrolytic sugar syrup for direct fermentation of levoglucosan to ethanol.

Science.gov (United States)

Chi, Zhanyou; Rover, Marjorie; Jun, Erin; Deaton, Mark; Johnston, Patrick; Brown, Robert C; Wen, Zhiyou; Jarboe, Laura R

2013-12-01

The application of pyrolytic sugars for biofuel production through fermentation is challenged by inhibitory contaminant compounds. Inhibition is so severe that only 0.25% sugar syrup can be used. In this study, overliming was tested as a simple detoxification method, using the Escherichia coli KO11+ lgk to directly convert levoglucosan into ethanol. After treatment with at least 14.8 g/L of Ca(OH)2, fermentation with 2% (w/v) pyrolytic sugar syrup was observed with no inhibition of ethanol production. Further investigation of treatment time and temperature showed that 8-16 h of treatment at 20°C, and 1-4 h of treatment at 60°C are necessary to obtain consistent ethanol production. The samples treated with 18.5 g/L Ca(OH)2 at 60°C for 4 h showed no inhibition at 2.5%. Multiple contaminants removed by the overliming treatment were identified. This study demonstrates that overliming is a promising method for detoxification of pyrolytic sugars for fermentation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Increasing alcohol yield in sugar fermentation

Energy Technology Data Exchange (ETDEWEB)

Colin, P

1962-02-20

The yield of alcohol from yeast fermentations of sugar solutions is increased 1.5 to 5% by the addition of 0.1 to 0.5 parts by volume of a monohydric saturated aliphatic alcohol of at least 6 C atoms in a straight chain such as hexanol or heptanol, or branched chain, such as 2-ethylbutanol or 2-ethylhexanol, or a mixture consisting mostly of C/sub 7/, C/sub 8/, C/sub 9/, or C/sub 10/ alcohols.

[Modeling of sugar content based on NIRS during cider-making fermentation].

Science.gov (United States)

Peng, Bang-Zhu; Yue, Tian-Li; Yuan, Ya-Hong; Gao, Zhen-Peng

2009-03-01

The sugar content and the matrix always are being changed during cider-making fermentation. In order to measure and monitor sugar content accurately and rapidly, it is necessary for the spectra to be sorted. Calibration models were established at different fermentation stages based on near infrared spectroscopy with artificial neural network. NIR spectral data were collected in the spectral region of 12 000-4 000 cm(-1) for the next analysis. After the different conditions for modeling sugar content were analyzed and discussed, the results indicated that the calibration models developed by the spectral data pretreatment of straight line subtraction(SLS) in the characteristic absorption spectra ranges of 7 502-6 472.1 cm(-1) at stage I and 6 102-5 446.2 cm(-1) at stage II were the best for sugar content. The result of comparison of different data pretreatment methods for establishing calibration model showed that the correlation coefficients of the models (R2) for stage I and II were 98.93% and 99.34% respectively and the root mean square errors of cross validation(RMSECV) for stage I and II were 4.42 and 1.21 g x L(-1) respectively. Then the models were tested and the results showed that the root mean square error of prediction (RMSEP) was 4.07 g x L(-1) and 1.13 g x L(-1) respectively. These demonstrated that the models the authors established are very well and can be applied to quick determination and monitoring of sugar content during cider-making fermentation.

Single and combined effects of acetic acid, furfural, and sugars on the growth of the pentose-fermenting yeast Meyerozyma guilliermondii.

Science.gov (United States)

Perna, Michelle Dos Santos Cordeiro; Bastos, Reinaldo Gaspar; Ceccato-Antonini, Sandra Regina

2018-02-01

The tolerance of the pentose-fermenting yeast Meyerozyma guilliermondii to the inhibitors released after the biomass hydrolysis, such as acetic acid and furfural, was surveyed. We first verified the effects of acetic acid and cell concentrations and initial pH on the growth of a M. guilliermondii strain in a semi-synthetic medium containing acetic acid as the sole carbon source. Second, the single and combined effects of furfural, acetic acid, and sugars (xylose, arabinose, and glucose) on the sugar uptake, cell growth, and ethanol production were also analysed. Growth inhibition occurred in concentrations higher than 10.5 g l -1 acetic acid and initial pH 3.5. The maximum specific growth rate (µ) was 0.023 h -1 and the saturation constant (ks) was 0.75 g l -1 acetic acid. Initial cell concentration also influenced µ. Acetic acid (initial concentration 5 g l -1 ) was co-consumed with sugars even in the presence of 20 mg l -1 furfural without inhibition to the yeast growth. The yeast grew and fermented sugars in a sugar-based medium with acetic acid and furfural in concentrations much higher than those usually found in hemicellulosic hydrolysates.

Growing sweet sorghum as a source of fermentable sugars for energy

Energy Technology Data Exchange (ETDEWEB)

Gascho, G.J.; Nichols, R.L.; Powell-Gaines, T.

1984-08-01

Studies were undertaken on the southern coastal plain (Georgia) of the USA on sweet sorghum to evaluate its potential as a fuel ethanol feedstock. Field experiments were designed over three years to study several aspects of the production of fermentable sugars from sweet sorghum and these included cultivar types, fertility needs, weed control and growth regulation. Wray was the best cultivar, producing a high sugar per hectare. To justify the operation of an ethanol plant, sweet sorghum should be harvested over a period of months, so cultivars were selected for yearly, medium and late maturity, thus ensuring a constant supply of feedstock over a four month period. The fertility needs of sweet sorghum appear to be relatively low and the yield response to applications of N, P, K are given. The best weed control was achieved by treating with Propazine plus Metolacheor. Application of several growth regulators such as Gibberellin didn't significantly increase the yield of sugars. Finally, a method to measure the fermentable sugars was developd using the Technicon Autoanalyser II.

The preparation and ethanol fermentation of high-concentration sugars from steam-explosion corn stover.

Science.gov (United States)

Xie, Hui; Wang, Fengqin; Yin, Shuangyao; Ren, Tianbao; Song, Andong

2015-05-01

In the field of biofuel ethanol, high-concentration- reducing sugars made from cellulosic materials lay the foundation for high-concentration ethanol fermentation. In this study, corn stover was pre-treated in a process combining chemical methods and steam explosion; the cellulosic hydrolyzed sugars obtained by fed-batch saccharification were then used as the carbon source for high-concentration ethanol fermentation. Saccharomyces cerevisiae 1308, Angel yeast, and Issatchenkia orientalis were shake-cultured with Pachysolen tannophilus P-01 for fermentation. Results implied that the ethanol yields from the three types of mixed strains were 4.85 g/100 mL, 4.57 g/100 mL, and 5.02 g/100 mL (separately) at yield rates of 91.6, 89.3, and 92.2%, respectively. Therefore, it was inferred that shock-fermentation using mixed strains achieved a higher ethanol yield at a greater rate in a shorter fermentation period. This study provided a theoretical basis and technical guidance for the fermentation of industrial high-concentrated cellulosic ethanol.

Steam drying compared to drum drying markedly increases early phase rumen fermentability of sugar beet pulp

DEFF Research Database (Denmark)

Nielsen, Mette Olaf; Larsen, Kasper; Jensen, Arne Sloth

2017-01-01

Freshly pressed and dried sugar beet pulp was sampled from 2 different factories located within a distance of 30 km and on 4 different dates. One factory was equipped with a steam dryer and the other with a drum dryer. A recognized in vitro technique was used to establish, how the drying process...... affected rumen fermentability of the pulp, since fibrous feeds (such as sugar beet pulp) rely on microbial fermentation in the rumen to be digestible to the cow. Steam dried pulp had a remarkable >60% higher fermentability compared to drum dried pulp during the first 12(-15) hours of fermentation...... (such as pectin) and small particles as low as 6.7-13.3 hours. Future feeding trials are needed to establish exactly how much the feeding value is increased in steam dried sugar beet pulp....

A Novel simultaneous-Saccharification-Fermentation Strategy for Efficient Co-fermentation of C5 and C6 Sugars Using Native, Non-GMO Yeasts

Energy Technology Data Exchange (ETDEWEB)

Varanasi, Sasidhar [Univ. of Toledo, OH (United States); Relue, Patricia [Univ. of Toledo, OH (United States)

2013-09-30

Economic bioethanol production is critically dependent upon the ability to convert both the hexose (C6) and pentose (C5) sugars resulting from cellulose and hemicellulose. C5 sugars are not readily fermentable by native Saccharomyces cerevisiae. Genetically Modified Organisms (GMOs) are designed to ferment xylose, but their stability, ethanol yield, environmental impact, and survival under conditions of industrial fermentation are unproven. In this project, we developed a novel approach for efficient fermentation of both C5 and C6 sugars using native S. Cerevisiae by exploiting its ability to produce ethanol from xylulose - the keto-isomer of xylose. While the isomerization of xylose to xylulose can be accomplished via commercially (and cheaply) available Xylose Isomerase (XI) (Sweetzyme™), this conversion has an extremely unfavorable equilibrium (xylose:xylose is about 5:1). To address this, we developed two alternate strategies. In the first, the two enzymes XI and urease are coimmobilized on solid support particles to enable complete isomerization of xylose to xylulose under pH conditions suitable for fermentation, in a simultaneous-isomerization-fermentation (SIF) mode. The ability of our technology to conduct isomerization of xylose under pH conditions suitable for both saccharification and fermentation opens the possibility of SSF with native yeasts for the first time. Herein, we performed specific research tasks for implementation of our technology in several modes of operation, including simultaneous-isomerization-and-fermentation (SIF), simultaneous-saccharification-and-isomerization (SSI) followed by fermentation, and SSF mode with the biomass feedstock poplar. The projected economics of our process are very favorable in comparison to the costs associated with engineering, licensing and propagating GMOs. This novel fermentation technology is readily accessible to rural farming economies for implementation in cellulosic ethanol production facilities.

Effect of pulp preconditioning on acidification, proteolysis, sugars and free fatty acids concentration during fermentation of cocoa (Theobroma cacao) beans.

Science.gov (United States)

Afoakwa, Emmanuel Ohene; Quao, Jennifer; Budu, Agnes Simpson; Takrama, Jemmy; Saalia, Firibu Kwesi

2011-11-01

Changes in acidification, proteolysis, sugars and free fatty acids (FFAs) concentrations of Ghanaian cocoa beans as affected by pulp preconditioning (pod storage or PS) and fermentation were investigated. Non-volatile acidity, pH, proteolysis, sugars (total, reducing and non-reducing) and FFAs concentrations were analysed using standard methods. Increasing PS consistently decreased the non-volatile acidity with concomitant increase in pH during fermentation of the beans. Fermentation decreased the pH of the unstored beans from 6.7 to 4.9 within the first 4 days and then increased slightly again to 5.3 by the sixth day. Protein, total sugars and non-reducing sugars decreased significantly (p cocoa beans was largely affected by fermentation than by PS.

Appropriate vacuolar acidification in Saccharomyces cerevisiae is associated with efficient high sugar fermentation.

Science.gov (United States)

Nguyen, Trung D; Walker, Michelle E; Gardner, Jennifer M; Jiranek, Vladimir

2018-04-01

Vacuolar acidification serves as a homeostatic mechanism to regulate intracellular pH, ion and chemical balance, as well as trafficking and recycling of proteins and nutrients, critical for normal cellular function. This study reports on the importance of vacuole acidification during wine-like fermentation. Ninety-three mutants (homozygous deletions in lab yeast strain, BY4743), which result in protracted fermentation when grown in a chemically defined grape juice with 200 g L -1 sugar (pH 3.5), were examined to determine whether fermentation protraction was in part due to a dysfunction in vacuolar acidification (VA) during the early stages of fermentation, and whether VA was responsive to the initial sugar concentration in the medium. Cells after 24 h growth were dual-labelled with propidium iodide and vacuolar specific probe 6-carboxyfluorescein diacetate (6-CFDA) and examined with a FACS analyser for viability and impaired VA, respectively. Twenty mutants showed a greater than two-fold increase in fluorescence intensity; the experimental indicator for vacuolar dysfunction; 10 of which have not been previously annotated to this process. With the exception of Δhog1, Δpbs2 and Δvph1 mutants, where dysfunction was directly related to osmolality; the remainder exhibited increased CF-fluorescence, independent of sugar concentration at 20 g L -1 or 200 g L -1 . These findings offer insight to the importance of VA to cell growth in high sugar media. Copyright © 2017 Elsevier Ltd. All rights reserved.

A viable method and configuration for fermenting biomass sugars to ethanol using native Saccharomyces cerevisiae.

Science.gov (United States)

Yuan, Dawei; Rao, Kripa; Varanasi, Sasidhar; Relue, Patricia

2012-08-01

A system that incorporates a packed bed reactor for isomerization of xylose and a hollow fiber membrane fermentor (HFMF) for sugar fermentation by yeast was developed for facile recovery of the xylose isomerase enzyme pellets and reuse of the cartridge loaded with yeast. Fermentation of pre-isomerized poplar hydrolysate produced using ionic liquid pretreatment in HFMF resulted in ethanol yields equivalent to that of model sugar mixtures of xylose and glucose. By recirculating model sugar mixtures containing partially isomerized xylose through the packed bed and the HFMF connected in series, 39 g/l ethanol was produced within 10h with 86.4% xylose utilization. The modular nature of this configuration has the potential for easy scale-up of the simultaneous isomerization and fermentation process without significant capital costs. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of gamma radiation on microbiological parameters of the ethanolic fermentation of sugar-cane must

International Nuclear Information System (INIS)

Alcarde, A.R.; Walder, J.M.M.; Horii, J.

2003-01-01

The influence of gamma radiation on reducing the population of some bacteria Bacillus and Lactobacillus that usually contaminate the sugar-cane must and its effects on acidity of the medium and viability of the yeast during fermentation were evaluated. The treatment with gamma radiation reduced the bacterial load of the sugar-cane must. Consequently, the volatile acidity produced during the fermentation of the must decreased and the viability of the yeast afterwards added increased

Effectiveness of Mosquito Trap with Sugar Fermented Attractant to the Vector of Dengue Hemorrhagic Fever

Directory of Open Access Journals (Sweden)

Endang Puji Astuti

2011-06-01

Full Text Available Aedes aegypti is the main vector of dengue fever that is still become health problem in the world. Various control efforts has been done at several areas through chemically or naturally control. Developing mosquitoes trapping tool is an alternative method to control mosquitoes besides insecticides utilization. This laboratorium research utilize sugar fermented process to yield CO2 as one of attractan to mosquito. Production of ethanol and CO2 can be yielded from anaerob sugar fermentation proccess (without O2 by khamir Saccharomyces cerevisiae activities. The trapped mosquitoes was observed up to 48 hours exposure, the highest average of mosquito trapped is on solution treatment with yeast 1 gram (43.2% and 40 gr sugar (48.4%. The highest effectivity of trapping tool both inside or outside was on the 14th day. There were declained amount of trapped mosquitos on 16th and 18th days. This laboratorium research has described that trapping tool with sugar fermented solution were effective to control population of dengue vector.

Fermentation of sugar to ethyl alcohol in the presence of proteolytic enzymes

Energy Technology Data Exchange (ETDEWEB)

Coates, E W; Conde Julio, C

1963-06-11

Sugar is fermented to EtOH by yeasts capable of elaborating zymase and proteolytic enzymes, the zymase component comprising exceptionally large amounts of phosphatase. Saccharomyces ellipsoideus was acclimated to 20% EtOH by growing on fresh pineapple juice in a medium consisting of malt sirup 15, sugar sirup 3, and pineapple juice 82%. An aqueous solution of 2000 gallons of sugar cane molasses in H/sub 2/O to give a Brix of 16/sup 0/ was placed in a 48,000-gallon fermentor. S. ellipsoideus with a cell constant of 1 x 10/sup 9/ cells/ml was added, with sufficient H/sub 2/SO/sub 4/ to adjust the pH to approximately 4.5. Fermentation was carried out at 35/sup 0/ until the Brix dropped to 8/sup 0/, after which it was brought back to 16/sup 0/ by adding 6000 gallons of sirup containing nutrients in H/sub 2/O. This process was repeated with another 6000 and then 2000 gallons of sirup. The total fermentation required 48 h and the EtOH content was 15.25% by volume. Te EtOH was recovered in the usual manner by removal of solids and fractional distillation.

Optimization of ethanol production by Zymomonas mobilis in sugar cane molasses fermentation

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Marcos Roberto Oliveira

2005-02-01

Full Text Available The present study aimed at the optimization of the ethanol production by Zymomonas mobilis CP4, during the fermentation of sugar cane molasses. As for the optimization process, the response surface methodology was applied, using a 33 incomplete factorial design, being the independent variables: total reducing sugar (TRS concentration in the molasses from 10, 55 and 100 g/L (x1; yeast extract concentration from 2, 11 and 20 g/L (x2, and fermentation time from 6, 15 and 24 hours (x3. The dependant variables or answers were the production and productivity of ethanol. By the analysis of the results, a good adjustment of the model to the experimental data was obtained. In the levels studied, the best condition for the production of ethanol was with 100 g/L TRS in the syrup, 2.0 g/L of yeast extract and the fermentation time between 20 and 24 hours, producing 30 g/L of ethanol.

Nitrifying aerobic granular sludge fermentation for releases of carbon source and phosphorus: The role of fermentation pH.

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Zou, Jinte; Pan, Jiyang; He, Hangtian; Wu, Shuyun; Xiao, Naidong; Ni, Yongjiong; Li, Jun

2018-07-01

The effect of fermentation pH (uncontrolled, 4 and 10) on the releases of carbon source and phosphorus from nitrifying aerobic granular sludge (N-AGS) was investigated. Meanwhile, metal ion concentration and microbial community characterization were explored during N-AGS fermentation. The results indicated that N-AGS fermentation at pH 10 significantly promoted the releases of soluble chemical oxygen demand (SCOD) and total volatile fatty acids (TVFAs). However, SCOD and TVFA released from N-AGS were inhibited at pH 4. Moreover, acidic condition promoted phosphorus release (mainly apatite) from N-AGS during anaerobic fermentation. Nevertheless, alkaline condition failed to increase phosphorus concentration due to the formation of chemical-phosphate precipitates. Compared with the previously reported flocculent sludge fermentation, N-AGS fermentation released more SCOD and TVFAs, possibly due to the greater extracellular polymeric substances content and some hydrolytic-acidogenic bacteria in N-AGS. Therefore, N-AGS alkaline fermentation facilitated the carbon source recovery, while N-AGS acidic fermentation benefited the phosphorus recovery. Copyright © 2018. Published by Elsevier Ltd.

Impact of mixed Torulaspora delbrueckii-Saccharomyces cerevisiae culture on high-sugar fermentation.

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Bely, Marina; Stoeckle, Philippe; Masneuf-Pomarède, Isabelle; Dubourdieu, Denis

2008-03-20

Conventional wine yeasts produce high concentrations of volatile acidity, mainly acetic acid, during high-sugar fermentation. This alcoholic fermentation by-product is highly detrimental to wine quality and, in some cases, levels may even exceed legal limits. In this study, a non-conventional species, Torulaspora delbrueckii, was used, in pure cultures and mixed with Saccharomyces cerevisiae yeast, to ferment botrytized musts. Fermentation rate, biomass growth, and the formation of volatile acidity, acetaldehyde, and glycerol were considered. This study demonstrated that T. delbrueckii, often described as a low acetic producer under standard conditions, retained this quality even in a high-sugar medium. Unlike S. cerevisiae, this species did not respond to the hyper-osmotic medium by increasing acetic production as soon as it is inoculated into the must. Nevertheless, this yeast produced low ethanol and biomass yields, and the fermentation was sluggish. As a result, T. delbrueckii fermentations do not reach the required ethanol content (14%vol.), although this species can survive at this concentration. A mixed culture of T. delbrueckii and S. cerevisiae was the best combination for improving the analytical profile of sweet wine, particularly volatile acidity and acetaldehyde production. A mixed T. delbrueckii/S. cerevisiae culture at a 20:1 ratio produced 53% less in volatile acidity and 60% less acetaldehyde than a pure culture of S. cerevisiae. Inoculating S. cerevisiae after 5 days' fermentation by T. delbrueckii had less effect on volatile acidity and acetaldehyde production and resulted in stuck fermentation. These results contribute to a better understanding of the behaviour of non-Saccharomyces and their potential application in wine industry.

Sugar-rich sweet sorghum is distinctively affected by wall polymer features for biomass digestibility and ethanol fermentation in bagasse.

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Li, Meng; Feng, Shengqiu; Wu, Leiming; Li, Ying; Fan, Chunfen; Zhang, Rui; Zou, Weihua; Tu, Yuanyuan; Jing, Hai-Chun; Li, Shizhong; Peng, Liangcai

2014-09-01

Sweet sorghum has been regarded as a typical species for rich soluble-sugar and high lignocellulose residues, but their effects on biomass digestibility remain unclear. In this study, we examined total 63 representative sweet sorghum accessions that displayed a varied sugar level at stalk and diverse cell wall composition at bagasse. Correlative analysis showed that both soluble-sugar and dry-bagasse could not significantly affect lignocellulose saccharification under chemical pretreatments. Comparative analyses of five typical pairs of samples indicated that DP of crystalline cellulose and arabinose substitution degree of non-KOH-extractable hemicelluloses distinctively affected lignocellulose crystallinity for high biomass digestibility. By comparison, lignin could not alter lignocellulose crystallinity, but the KOH-extractable G-monomer predominately determined lignin negative impacts on biomass digestions, and the G-levels released from pretreatments significantly inhibited yeast fermentation. The results also suggested potential genetic approaches for enhancing soluble-sugar level and lignocellulose digestibility and reducing ethanol conversion inhibition in sweet sorghum. Copyright © 2014. Published by Elsevier Ltd.

Lignocellulosic sugar management for xylitol and ethanol fermentation with multiple cell recycling by Kluyveromyces marxianus IIPE453.

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Dasgupta, Diptarka; Ghosh, Debashish; Bandhu, Sheetal; Adhikari, Dilip K

2017-07-01

Optimum utilization of fermentable sugars from lignocellulosic biomass to deliver multiple products under biorefinery concept has been reported in this work. Alcohol fermentation has been carried out with multiple cell recycling of Kluyveromyces marxianus IIPE453. The yeast utilized xylose-rich fraction from acid and steam treated biomass for cell generation and xylitol production with an average yield of 0.315±0.01g/g while the entire glucose rich saccharified fraction had been fermented to ethanol with high productivity of 0.9±0.08g/L/h. A detailed insight into its genome illustrated the strain's complete set of genes associated with sugar transport and metabolism for high-temperature fermentation. A set flocculation proteins were identified that aided in high cell recovery in successive fermentation cycles to achieve alcohols with high productivity. We have brought biomass derived sugars, yeast cell biomass generation, and ethanol and xylitol fermentation in one platform and validated the overall material balance. 2kg sugarcane bagasse yielded 193.4g yeast cell, and with multiple times cell recycling generated 125.56g xylitol and 289.2g ethanol (366mL). Copyright © 2017 Elsevier GmbH. All rights reserved.

Effects of the addition of different nitrogen sources in the tequila fermentation process at high sugar concentration.

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Arrizon, J; Gschaedler, A

2007-04-01

To study the effect of the addition of different nitrogen sources at high sugar concentration in the tequila fermentation process. Fermentations were performed at high sugar concentration (170 g l(-1)) using Agave tequilana Weber blue variety with and without added nitrogen from different sources (ammonium sulfate; glutamic acid; a mixture of ammonium sulfate and amino acids) during the exponential phase of growth. All the additions increased the fermentation rate and alcohol efficiency. The level of synthesis of volatile compounds depended on the source added. The concentration of amyl alcohols and isobutanol were decreased while propanol and acetaldehyde concentration increased. The most efficient nitrogen sources for fermentation rate were ammonium sulfate and the mixture of ammonium sulfate and amino acids. The level of volatile compounds produced depended upon types of nitrogen. The synthesis of some volatile compounds increased while others decreased with nitrogen addition. The addition of nitrogen could be a strategy for improving the fermentation rate and efficiency in the tequila fermentation process at high sugar Agave tequilana concentration. Furthermore, the sensory quality of the final product may change because the synthesis of the volatile compounds is modified.

Influence of fiber degradation and concentration of fermentable sugars on simultaneous saccharification and fermentation of high-solids spruce slurry to ethanol.

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Hoyer, Kerstin; Galbe, Mats; Zacchi, Guido

2013-10-08

Saccharification and fermentation of pretreated lignocellulosic materials, such as spruce, should be performed at high solids contents in order to reduce the cost of the produced bioethanol. However, this has been shown to result in reduced ethanol yields or a complete lack of ethanol production. Previous studies have shown inconsistent results when prehydrolysis is performed at a higher temperature prior to the simultaneous saccharification and fermentation (SSF) of steam-pretreated lignocellulosic materials. In some cases, a significant increase in overall ethanol yield was reported, while in others, a slight decrease in ethanol yield was observed. In order to investigate the influence of prehydrolysis on high-solids SSF of steam-pretreated spruce slurry, in the present study, the presence of fibers and inhibitors, degree of fiber degradation and initial fermentable sugar concentration has been studied. SSF of whole steam-pretreated spruce slurry at a solids content of 13.7% water-insoluble solids (WIS) resulted in a very low overall ethanol yield, mostly due to poor fermentation. The yeast was, however, able to ferment the washed slurry and the liquid fraction of the pretreated slurry. Performing prehydrolysis at 48°C for 22 hours prior to SSF of the whole pretreated slurry increased the overall ethanol yield from 3.9 to 62.1%. The initial concentration of fermentable sugars in SSF could not explain the increase in ethanol yield in SSF with prehydrolysis. Although the viscosity of the material did not appear to decrease significantly during prehydrolysis, the degradation of the fibers prior to the addition of the yeast had a positive effect on ethanol yield when using whole steam-pretreated spruce slurry. The results of the present study suggest that the increase in ethanol yield from SSF when performing prehydrolysis is a result of fiber degradation rather than a decrease in viscosity. The increased concentration of fermentable sugars at the beginning of the

Artificial neural network approach to modeling of alcoholic fermentation of thick juice from sugar beet processing

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Jokić Aleksandar I.

2012-01-01

Full Text Available In this paper the bioethanol production in batch culture by free Saccharomyces cerevisiae cells from thick juice as intermediate product of sugar beet processing was examined. The obtained results suggest that it is possible to decrease fermentation time for the cultivation medium based on thick juice with starting sugar content of 5-15 g kg-1. For the fermentation of cultivation medium based on thick juice with starting sugar content of 20 and 25 g kg-1 significant increase in ethanol content was attained during the whole fermentation process, resulting in 12.51 and 10.95 dm3 m-3 ethanol contents after 48 h, respectively. Other goals of this work were to investigate the possibilities for experimental results prediction using artificial neural networks (ANNs and to find its optimal topology. A feed-forward back-propagation artificial neural network was used to test the hypothesis. As input variables fermentation time and starting sugar content were used. Neural networks had one output value, ethanol content, yeast cell number or sugar content. There was one hidden layer and the optimal number of neurons was found to be nine for all selected network outputs. In this study transfer function was tansig and the selected learning rule was Levenberg-Marquardt. Results suggest that artificial neural networks are good prediction tool for selected network outputs. It was found that experimental results are in very good agreement with computed ones. The coefficient of determination (the R-squared was found to be 0.9997, 0.9997 and 0.9999 for ethanol content, yeast cell number and sugar content, respectively.

Technical and economic assessments of storage techniques for long-term retention of industrial-beet sugar for non-food industrial fermentations

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Vargas-Ramirez, Juan Manuel

Industrial beets may compete against corn grain as an important source of sugars for non-food industrial fermentations. However, dependable and energy-efficient systems for beet sugar storage and processing are necessary to help establish industrial beets as a viable sugar feedstock. Therefore, technical and economic aspects of beet sugar storage and processing were evaluated. First, sugar retention was evaluated in whole beets treated externally with either one of two antimicrobials or a senescence inhibitor and stored for 36 wk at different temperature and atmosphere combinations. Although surface treatment did not improve sugar retention, full retention was enabled by beet dehydration caused by ambient air at 25 °C and with a relative humidity of 37%. This insight led to the evaluation of sugar retention in ground-beet tissue ensiled for 8 wk at different combinations of acidic pH, moisture content (MC), and sugar:solids. Some combinations of pH ≤ 4.0 and MC ≤ 67.5% enabled retentions of at least 90%. Yeast fermentability was also evaluated in non-purified beet juice acidified to enable long-term storage and partially neutralized before fermentation. None of the salts synthesized through juice acidification and partial neutralization inhibited yeast fermentation at the levels evaluated in that work. Conversely, yeast fermentation rates significantly improved in the presence of ammonium salts, which appeared to compensate for nitrogen deficiencies. Capital and operating costs for production and storage of concentrated beet juice for an ethanol plant with a production capacity of 76 x 106 L y-1 were estimated on a dry-sugar basis as U.S. ¢34.0 kg-1 and ¢2.2 kg-1, respectively. Storage and processing techniques evaluated thus far prove that industrial beets are a technically-feasible sugar feedstock for ethanol production.

Evaluation of the fermentation of high gravity thick sugar beet juice worts for efficient bioethanol production

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2013-01-01

Background Sugar beet and intermediates of sugar beet processing are considered to be very attractive feedstock for ethanol production due to their content of fermentable sugars. In particular, the processing of the intermediates into ethanol is considerably facilitated because it does not require pretreatment or enzymatic treatment in contrast to production from starch raw materials. Moreover, the advantage of thick juice is high solid substance and saccharose content which eliminates problems with the storability of this feedstock. Results The objective of this study were to investigate bioethanol production from thick juice worts and the effects of their concentration, the type of mineral supplement, as well as the dose of yeast inoculum on fermentation dynamics and ethanol yield. The obtained results show that to ensure efficient ethanolic fermentation of high gravity thick juice worts, one needs to use a yeast strain with high ethanol tolerance and a large amount of inoculum. The highest ethanol yield (94.9 ± 2.8% of the theoretical yield) and sugars intake of 96.5 ± 2.9% were obtained after the fermentation of wort with an extract content of 250 g/kg supplemented with diammonium hydrogen phosphate (0.3 g/L of wort) and inoculated with 2 g of Ethanol Red dry yeast per L of wort. An increase in extract content in the fermentation medium from 250 g/L to 280 g/kg resulted in decreased efficiency of the process. Also the distillates originating from worts with an extract content of 250 g/kg were characterized by lower acetaldehyde concentration than those obtained from worts with an extract content of 280 g/kg. Conclusions Under the favorable conditions determined in our experiments, 38.9 ± 1.2 L of 100% (v/v) ethyl alcohol can be produced from 100 kg of thick juice. The obtained results show that the selection of process conditions and the yeast for the fermentation of worts with a higher sugar content can improve the economic performance of the

Development of lotus root fermented sugar syrup as a functional food supplement/condiment and evaluation of its physicochemical, nutritional and microbiological properties.

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Shukla, Shruti; Park, Juyeon; Park, Jung Hyun; Lee, Jong Suk; Kim, Myunghee

2018-02-01

Lotus ( Nelumbo nucifera ) root has been used as an edible vegetable in East Asia for thousands of years. The present research was aimed to explore the physicochemical, nutritional and microbiological safety of lotus root fermented sugar syrup as a fermented food supplement or condiment for human health benefits. In this study, the physicochemical, nutritional and microbiological safety properties of lotus root syrup fermented with 57° Brix brown sugar at different time periods until 6 months (180 days) was investigated. There was a significant improvement as compared to 57° Brix brown sugar broth (as a control) in the total acceptability and physicochemical properties of lotus root sugar syrup samples such as pH and color improvement. The red color values of 180 days lotus root fermented sugar syrup samples were significantly enhanced (6.85 ± 0.58) when compared with the control (0.20 ± 0.15). In addition, the total protein content was increased from 8.27 ± 0.86 to 392.33 ± 7.19 μg/mL, along with the increase in fermentation time reaching to the level of consumption acceptability. All the lotus root fermented sugar syrup samples were subjected to microbiological analysis. It was found that the coliform, Bacillus cereus , Escherichia coli , Salmonella and Staphylococcus aureus counts were not detected in majority of the samples, confirming the high degree of hygiene processing of lotus root fermented sugar syrup samples for its use as a food supplement or condiment.

Improve the Recovery of Fermentable Sugar from Rice Straw by Sonication and Its Mathematical Modeling

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Bhattacharyya, Saurav; Dutta, Somenath; Datta, Sidhartha; Bhattacharjee, Chiranjib

2012-08-01

Rice straw is waste renewable agricultural biomass, which contains sufficient amount of fermentable sugars like glucose, galactose fructose, xylose etc. These sugars can be treated with fermentation pathway to produce ethanol. Hydrolysis of pretreated rice straw in dilute sulfuric acid was investigated at different acid concentrations (0.25-0.75 % w/v), and sonication was carried out to improve the extent of sugar extraction. The current work examines the effect of sonication on extraction of total reducing sugar (TRS) and an empirical mathematical model has been established to predict it. Effects of various operating variables of sonication, including amplitude (60-100 %), cycle (0.6-1.0), treatment time (0-15 min) have been analyzed for each acid concentration. Observation shows that on optimization of the sonication conditions (100 % amplitude, 0.8 cycle and 10 min) around 90 % improvement of TRS extraction occurs at 0.5 % (w/v) acid concentration.

Over production of fermentable sugar for bioethanol production from carbohydrate-rich Malaysian food waste via sequential acid-enzymatic hydrolysis pretreatment.

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Hafid, Halimatun Saadiah; Nor 'Aini, Abdul Rahman; Mokhtar, Mohd Noriznan; Talib, Ahmad Tarmezee; Baharuddin, Azhari Samsu; Umi Kalsom, Md Shah

2017-09-01

In Malaysia, the amount of food waste produced is estimated at approximately 70% of total municipal solid waste generated and characterised by high amount of carbohydrate polymers such as starch, cellulose, and sugars. Considering the beneficial organic fraction contained, its utilization as an alternative substrate specifically for bioethanol production has receiving more attention. However, the sustainable production of bioethanol from food waste is linked to the efficient pretreatment needed for higher production of fermentable sugar prior to fermentation. In this work, a modified sequential acid-enzymatic hydrolysis process has been developed to produce high concentration of fermentable sugars; glucose, sucrose, fructose and maltose. The process started with hydrothermal and dilute acid pretreatment by hydrochloric acid (HCl) and sulphuric acid (H 2 SO 4 ) which aim to degrade larger molecules of polysaccharide before accessible for further steps of enzymatic hydrolysis by glucoamylase. A kinetic model is proposed to perform an optimal hydrolysis for obtaining high fermentable sugars. The results suggested that a significant increase in fermentable sugar production (2.04-folds) with conversion efficiency of 86.8% was observed via sequential acid-enzymatic pretreatment as compared to dilute acid pretreatment (∼42.4% conversion efficiency). The bioethanol production by Saccharomyces cerevisiae utilizing fermentable sugar obtained shows ethanol yield of 0.42g/g with conversion efficiency of 85.38% based on the theoretical yield was achieved. The finding indicates that food waste can be considered as a promising substrate for bioethanol production. Copyright © 2017. Published by Elsevier Ltd.

Performance of several Saccharomyces strains for the alcoholic fermentation of sugar-sweetened high-strength wastewaters: Comparative analysis and kinetic modelling.

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Comelli, Raúl N; Seluy, Lisandro G; Isla, Miguel A

2016-12-25

This work focuses on the performance of ten commercial Saccharomyces yeast strains in the batch alcoholic fermentation of sugars contained in selected industrial wastewaters from the soft drink industry. Fermentation has been applied successfully to treat these effluents prior to their disposal. Although many strains were investigated, similar behaviour was observed between all of the Saccharomyces strains tested. When media were inoculated with 2gL -1 of yeast, all strains were able to completely consume the available sugars in less than 14h. Thus, any of the strains studied in this work could be used in non-conventional wastewater treatment processes based on alcoholic fermentation. However, ethanol production varied between strains, and these differences could be significant from a production point of view. Saccharomyces bayanus produced the most ethanol, with a mean yield of 0.44g ethanol g sugarconsumed -1 and an ethanol specific production rate of 5.96g ethanol (Lh) -1 . As the assayed soft drinks wastewaters contain about 105g sugar /L of fermentable sugars, the concentration of ethanol achieved after the fermentations process was 46.2g ethanol /L. A rigorous kinetic modelling methodology was used to model the Saccharomyces bayanus fermentation process. The kinetic model included coupled mass balances and a minimal number of parameters. A simple unstructured model based on the Andrews equation (substrate inhibition) was developed. This model satisfactorily described biomass growth, sugar consumption and bioethanol production. In addition to providing insights into the fermentative performance of potentially relevant strains, this work can facilitate the design of large-scale ethanol production processes that use wastewaters from the sugar-sweetened beverage industry as feedstock. Copyright © 2016 Elsevier B.V. All rights reserved.

Changes in the bacterial community in the fermentation process of kôso, a Japanese sugar-vegetable fermented beverage.

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Chiou, Tai-Ying; Suda, Wataru; Oshima, Kenshiro; Hattori, Masahira; Takahashi, Tomoya

2017-02-01

Kôso is a Japanese fermented beverage made with over 20 kinds of vegetables, mushrooms, and sugars. The changes in the bacterial population of kôso during fermentation at 25 °C over a period of 10 days were studied using 454 pyrosequencing of the 16S rRNA gene. The analysis detected 224 operational taxonomic units (OTUs) clustered from 8 DNA samples collected on days 0, 3, 7, and 10 from two fermentation batches. Proteobacteria were the dominant phylum in the starting community, but were replaced by Firmicutes within three days. Seventy-eight genera were identified from the 224 OTUs, in which Bifidobacterium, Leuconostoc, Lactococcus, and Lactobacillus dominated, accounting for over 96% of the total bacterial population after three days' fermentation. UniFrac-Principal Coordinate Analysis of longitudinal fermented samples revealed dramatic changes in the bacterial community in kôso, resulting in significantly low diversity at the end of fermentation as compared with the complex starting community.

Bioethanol production: an integrated process of low substrate loading hydrolysis-high sugars liquid fermentation and solid state fermentation of enzymatic hydrolysis residue.

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Chu, Qiulu; Li, Xin; Ma, Bin; Xu, Yong; Ouyang, Jia; Zhu, Junjun; Yu, Shiyuan; Yong, Qiang

2012-11-01

An integrated process of enzymatic hydrolysis and fermentation was investigated for high ethanol production. The combination of enzymatic hydrolysis at low substrate loading, liquid fermentation of high sugars concentration and solid state fermentation of enzymatic hydrolysis residue was beneficial for conversion of steam explosion pretreated corn stover to ethanol. The results suggested that low substrate loading hydrolysis caused a high enzymatic hydrolysis yield; the liquid fermentation of about 200g/L glucose by Saccharomyces cerevisiae provided a high ethanol concentration which could significantly decrease cost of the subsequent ethanol distillation. A solid state fermentation of enzymatic hydrolysis residue was combined, which was available to enhance ethanol production and cellulose-to-ethanol conversion. The results of solid state fermentation demonstrated that the solid state fermentation process accompanied by simultaneous saccharification and fermentation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Citric acid fermentation medium from sugar waste

Energy Technology Data Exchange (ETDEWEB)

Asai, S.; Yarita, K.; Uchio, R.; Kikuchi, K.

1977-11-02

Wastes from a sugar refinery are hydrolyzed to yield fructose and glucose; a part of the fructose is removed from the hydrolyzate by treating with lime and the remaining hydrolyzate is used as a C source for citric acid fermentation. Thus, 1 kg beet molasses was dissolved in 2.5 L water, adjusted to pH 1.5, hydrolyzed at 60/sup 0/ for 4 h, neutralized with Ca(OH)/sub 2/, and the precipitate was removed. The hydrolyzate was cooled to 0/sup 0/, mixed with a solution containing 205 g Ca(OH)/sub 2/, seeded with fructose, and allowed to stand. The precipitate was suspended in cold water, neutralized with H/sub 2/SO/sub 4/, and filtered to obtain a solution containing 169 g fructose and 6.3 g glucose. The filtrate from the Ca(OH)/sub 2/ precipitation was neutralized with H/sub 2/SO/sub 4/ and removal of precipitate yielded a solution containing 87 g fructose and 220 g glucose, which was used as a C source for citric acid fermentation with Aspergillus niger AJ7015.

Hydrogen production from sugar beet juice using an integrated biohydrogen process of dark fermentation and microbial electrolysis cell.

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

2015-12-01

An integrated dark fermentation and microbial electrochemical cell (MEC) process was evaluated for hydrogen production from sugar beet juice. Different substrate to inoculum (S/X) ratios were tested for dark fermentation, and the maximum hydrogen yield was 13% of initial COD at the S/X ratio of 2 and 4 for dark fermentation. Hydrogen yield was 12% of initial COD in the MEC using fermentation liquid end products as substrate, and butyrate only accumulated in the MEC. The overall hydrogen production from the integrated biohydrogen process was 25% of initial COD (equivalent to 6 mol H2/mol hexoseadded), and the energy recovery from sugar beet juice was 57% using the combined biohydrogen. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improving L-arabinose utilization of pentose fermenting Saccharomyces cerevisiae cells by heterologous expression of L-arabinose transporting sugar transporters

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Boles Eckhard

2011-10-01

Full Text Available Abstract Background Hydrolysates of plant biomass used for the production of lignocellulosic biofuels typically contain sugar mixtures consisting mainly of D-glucose and D-xylose, and minor amounts of L-arabinose. The yeast Saccharomyces cerevisiae is the preferred microorganism for the fermentative production of ethanol but is not able to ferment pentose sugars. Although D-xylose and L-arabinose fermenting S. cerevisiae strains have been constructed recently, pentose uptake is still a limiting step in mixed sugar fermentations. Results Here we described the cloning and characterization of two sugar transporters, AraT from the yeast Scheffersomyces stipitis and Stp2 from the plant Arabidopsis thaliana, which mediate the uptake of L-arabinose but not of D-glucose into S. cerevisiae cells. A yeast strain lacking all of its endogenous hexose transporter genes and expressing a bacterial L-arabinose utilization pathway could no longer take up and grow with L-arabinose as the only carbon source. Expression of the heterologous transporters supported uptake and utilization of L-arabinose especially at low L-arabinose concentrations but did not, or only very weakly, support D-glucose uptake and utilization. In contrast, the S. cerevisiae D-galactose transporter, Gal2, mediated uptake of both L-arabinose and D-glucose, especially at high concentrations. Conclusions Using a newly developed screening system we have identified two heterologous sugar transporters from a yeast and a plant which can support uptake and utilization of L-arabinose in L-arabinose fermenting S. cerevisiae cells, especially at low L-arabinose concentrations.

Xylanase and feruloyl esterase from actinomycetes cultures could enhance sugarcane bagasse hydrolysis in the production of fermentable sugars.

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Rahmani, Nanik; Kahar, Prihardi; Lisdiyanti, Puspita; Hermiati, Euis; Lee, Jaemin; Yopi; Prasetya, Bambang; Ogino, Chiaki; Kondo, Akihiko

2018-02-23

The addition of enzymes that are capable of degrading hemicellulose has a potential to reduce the need for commercial enzymes during biomass hydrolysis in the production of fermentable sugars. In this study, a high xylanase producing actinomycete strain (Kitasatospora sp. ID06-480) and the first ethyl ferulate producing actinomycete strain (Nonomuraea sp. ID06-094) were selected from 797 rare actinomycetes, respectively, which were isolated in Indonesia. The addition (30%, v/v) of a crude enzyme supernatant from the selected strains in sugarcane bagasse hydrolysis with low-level loading (1 FPU/g-biomass) of Cellic® CTec2 enhanced both the released amount of glucose and reducing sugars. When the reaction with Ctec2 was combined with crude enzymes containing either xylanase or feruloyl esterase, high conversion yield of glucose from cellulose at 60.5% could be achieved after 72 h-saccharification.

Detoxification and fermentation of pyrolytic sugar for ethanol production.

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Wang, Hui; Livingston, Darrell; Srinivasan, Radhakrishnan; Li, Qi; Steele, Philip; Yu, Fei

2012-11-01

The sugars present in bio-oil produced by fast pyrolysis can potentially be fermented by microbial organisms to produce cellulosic ethanol. This study shows the potential for microbial digestion of the aqueous fraction of bio-oil in an enrichment medium to consume glucose and produce ethanol. In addition to glucose, inhibitors such as furans and phenols are present in the bio-oil. A pure glucose enrichment medium of 20 g/l was used as a standard to compare with glucose and aqueous fraction mixtures for digestion. Thirty percent by volume of aqueous fraction in media was the maximum additive amount that could be consumed and converted to ethanol. Inhibitors were removed by extraction, activated carbon, air stripping, and microbial methods. After economic analysis, the cost of ethanol using an inexpensive fermentation medium in a large scale plant is approximately $14 per gallon.

Simultaneous saccharification and co-fermentation of peracetic acid pretreated sugar cane bagasse

Energy Technology Data Exchange (ETDEWEB)

Teixeira, L.C. [Fundacao Centro Tecnologico de Minas Gerais, Belo Horizonte (Brazil); Linden, J.C.; Schroeder, H.A. [Colorado State University, Fort Collins, CO (United States)

1999-07-01

Previous work in our laboratory has demonstrated that peracetic acid improves the enzymatic digestibility of lignocellulosic materials. From the same studies, use of dilute alkali solutions as a pre-pretreatment prior to peracetic acid lignin oxidation increases sugar conversion yields in a synergistic, not additive, manner. Deacetylation of xylan is conducted easily by use of dilute alkali solutions at mild conditions. In this paper, the effectiveness of peracetic acid pretreatment of sugar cane bagasse combined with an alkaline pre-pretreatment, is evaluated through simultaneous saccharification and co-fermentation (SSCF) procedures. A practical 92% of theoretical ethanol yield using recombinant Zymomonas mobilis CP4/pZB5 is achieved using 6% NaOH/I5% peracetic acid pretreated substrate. No sugar accumulation is observed during SSCF; the recombinant microorganism exhibits greater glucose utilization rates than those of xylose. Acetate levels at the end of the co-fermentations are less than 0.2% (w/v). Based on demonstrated reduction of acetyl groups of the biomass, alkaline pre-pretreatments help to reduce peracetic acid requirements. The influence of deacetylation is more pronounced in combined pretreatments using lower peracetic acid loadings. Stereochemical impediments of the acetyl groups in hemicellulase on the activity of specific enzymes may be involved. (author)

Automated assay for screening the enzymatic release of reducing sugars from micronized biomass

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Asther Marcel

2010-07-01

Full Text Available Abstract Background To reduce the production cost of bioethanol obtained from fermentation of the sugars provided by degradation of lignocellulosic biomass (i.e., second generation bioethanol, it is necessary to screen for new enzymes endowed with more efficient biomass degrading properties. This demands the set-up of high-throughput screening methods. Several methods have been devised all using microplates in the industrial SBS format. Although this size reduction and standardization has greatly improved the screening process, the published methods comprise one or more manual steps that seriously decrease throughput. Therefore, we worked to devise a screening method devoid of any manual steps. Results We describe a fully automated assay for measuring the amount of reducing sugars released by biomass-degrading enzymes from wheat-straw and spruce. The method comprises two independent and automated steps. The first step is the making of "substrate plates". It consists of filling 96-well microplates with slurry suspensions of micronized substrate which are then stored frozen until use. The second step is an enzymatic activity assay. After thawing, the substrate plates are supplemented by the robot with cell-wall degrading enzymes where necessary, and the whole process from addition of enzymes to quantification of released sugars is autonomously performed by the robot. We describe how critical parameters (amount of substrate, amount of enzyme, incubation duration and temperature were selected to fit with our specific use. The ability of this automated small-scale assay to discriminate among different enzymatic activities was validated using a set of commercial enzymes. Conclusions Using an automatic microplate sealer solved three main problems generally encountered during the set-up of methods for measuring the sugar-releasing activity of plant cell wall-degrading enzymes: throughput, automation, and evaporation losses. In its present set-up, the

Role of alpha-glucosidase in the fermentable sugar composition of sorghum malt mashes

CSIR Research Space (South Africa)

Taylor, JRN

1994-11-01

Full Text Available The cause of the high glucose to maltose ratio in sorghum malt worts was studied. Mashing temperature and pH strongly affected both the amount of glucose and the proportion of glucose relative to total fermentable sugars. The relative proportion...

Kinetic Modeling of Ethanol Batch Fermentation by Escherichia Coli FBWHR Using Hot-Water Sugar Maple Wood Extract Hydrolyzate as Substrate

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Yang Wang

2014-12-01

Full Text Available A recombinant strain of Escherichia coli FBWHR was used for ethanol fermentation from hot-water sugar maple wood extract hydrolyzate in batch experiments. Kinetic studies of cell growth, sugar utilization and ethanol production were investigated at different initial total sugar concentrations of wood extract hydrolyzate. The highest ethanol concentration of 24.05 g/L was obtained using an initial total sugar concentration of 70.30 g/L. Unstructured models were developed to describe cell growth, sugar utilization and ethanol production and validated by comparing the predictions of model and experimental data. The results from this study could be expected to provide insights into the process performance, optimize the process and aid in the design of processes for large-scale production of ethanol fermentation from woody biomass.

Flexible biorefinery for producing fermentation sugars, lignin and pulp from corn stover.

Science.gov (United States)

Kadam, Kiran L; Chin, Chim Y; Brown, Lawrence W

2008-05-01

A new biorefining process is presented that embodies green processing and sustainable development. In the spirit of a true biorefinery, the objective is to convert agricultural residues and other biomass feedstocks into value-added products such as fuel ethanol, dissolving pulp, and lignin for resin production. The continuous biomass fractionation process yields a liquid stream rich in hemicellulosic sugars, a lignin-rich liquid stream, and a solid cellulose stream. This paper generally discusses potential applications of the three streams and specifically provides results on the evaluation of the cellulose stream from corn stover as a source of fermentation sugars and specialty pulp. Enzymatic hydrolysis of this relatively pure cellulose stream requires significantly lower enzyme loadings because of minimal enzyme deactivation from nonspecific binding to lignin. A correlation was shown to exist between lignin removal efficiency and enzymatic digestibility. The cellulose produced was also demonstrated to be a suitable replacement for hardwood pulp, especially in the top ply of a linerboard. Also, the relatively pure nature of the cellulose renders it suitable as raw material for making dissolving pulp. This pulping approach has significantly smaller environmental footprint compared to the industry-standard kraft process because no sulfur- or chlorine-containing compounds are used. Although this option needs some minimal post-processing, it produces a higher value commodity than ethanol and, unlike ethanol, does not need extensive processing such as hydrolysis or fermentation. Potential use of low-molecular weight lignin as a raw material for wood adhesive production is discussed as well as its use as cement and feed binder. As a baseline application the hemicellulosic sugars captured in the hydrolyzate liquor can be used to produce ethanol, but potential utilization of xylose for xylitol fermentation is also feasible. Markets and values of these applications are

Development of a mathematical model describing hydrolysis and co-fermentation of C6 and C5 sugars

DEFF Research Database (Denmark)

Morales Rodriguez, Ricardo; Gernaey, Krist; Meyer, Anne S.

2010-01-01

saccharification and co-fermentation (SSCF) of C6 and C5 sugars. Model construction has been carried out by combining existing mathematical models for enzymatic hydrolysis on the one hand and co-fermentation on the other hand. An inhibition of ethanol on cellulose conversion was introduced in order to increase...

Kinetics of sugars consumption and ethanol inhibition in carob pulp fermentation by Saccharomyces cerevisiae in batch and fed-batch cultures.

Science.gov (United States)

Lima-Costa, Maria Emília; Tavares, Catarina; Raposo, Sara; Rodrigues, Brígida; Peinado, José M

2012-05-01

The waste materials from the carob processing industry are a potential resource for second-generation bioethanol production. These by-products are small carob kibbles with a high content of soluble sugars (45-50%). Batch and fed-batch Saccharomyces cerevisiae fermentations of high density sugar from carob pods were analyzed in terms of the kinetics of sugars consumption and ethanol inhibition. In all the batch runs, 90-95% of the total sugar was consumed and transformed into ethanol with a yield close to the theoretical maximum (0.47-0.50 g/g), and a final ethanol concentration of 100-110 g/l. In fed-batch runs, fresh carob extract was added when glucose had been consumed. This addition and the subsequent decrease of ethanol concentrations by dilution increased the final ethanol production up to 130 g/l. It seems that invertase activity and yeast tolerance to ethanol are the main factors to be controlled in carob fermentations. The efficiency of highly concentrated carob fermentation makes it a very promising process for use in a second-generation ethanol biorefinery.

In vitro fermentability of sugar beet pulp derived oligosaccharides using human and pig fecal inocula

NARCIS (Netherlands)

Leijdekkers, A.G.M.; Aguirre, M.; Venema, K.; Bosch, G.; Gruppen, H.; Schols, H.A.

2014-01-01

The in vitro fermentation characteristics of different classes of sugar beet pectic oligosaccharides (SBPOS) were studied using human and pig fecal inocula. The SBPOS consisted mainly of partially acetylated rhamnogalacturonan oligosaccharides and partially methyl-esterified/acetylated

In Vitro fermentability of sugar beet pulp derived oligosaccharides using human and pig fecal inocula

NARCIS (Netherlands)

Leijdekkers, A.G.M.; Aguirre, M.; Venema, K.; Bosch, G.; Gruppen, H.; Schols, H.A.

2014-01-01

The in vitro fermentation characteristics of different classes of sugar beet pectic oligosaccharides (SBPOS) were studied using human and pig fecal inocula. The SBPOS consisted mainly of partially acetylated rhamnogalacturonan-oligosaccharides and partially methyl esterified/acetylated

Effect of the presence of initial ethanol on ethanol production in sugar cane juice fermented by Zymomonas mobilis

OpenAIRE

Tano,Marcia Sadae; Buzato,João Batista

2003-01-01

Ethanol production in sugar cane juice in high initial sugar concentration, fermented by Z. mobilis in the presence and absence of ethanol, was evaluated. Ethanol production was low in both media. The presence of initial ethanol in the sugar cane juice reduced ethanol production by 48.8%, biomass production by 25.0% and the total sugar consumption by 28.3%. The presence of initial ethanol in the medium did not affect significantly levan production and biomass yield coefficient (g biomass/g su...

Simultaneous Saccharification and Fermentation of Sugar Beet Pulp with Mixed Bacterial Cultures for Lactic Acid and Propylene Glycol Production

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Joanna Berlowska

2016-10-01

Full Text Available Research into fermentative production of lactic acid from agricultural by-products has recently concentrated on the direct conversion of biomass, whereby pure sugars are replaced with inexpensive feedstock in the process of lactic acid production. In our studies, for the first time, the source of carbon used is sugar beet pulp, generated as a by-product of industrial sugar production. In this paper, we focus on the simultaneous saccharification of lignocellulosic biomass and fermentation of lactic acid, using mixed cultures with complementary assimilation profiles. Lactic acid is one of the primary platform chemicals, and can be used to synthesize a wide variety of useful products, including green propylene glycol. A series of controlled batch fermentations was conducted under various conditions, including pretreatment with enzymatic hydrolysis. Inoculation was performed in two sequential stages, to avoid carbon catabolite repression. Biologically-synthesized lactic acid was catalytically reduced to propylene glycol over 5% Ru/C. The highest lactic acid yield was obtained with mixed cultures. The yield of propylene glycol from the biological lactic acid was similar to that obtained with a water solution of pure lactic acid. Our results show that simultaneous saccharification and fermentation enables generation of lactic acid, suitable for further chemical transformations, from agricultural residues.

In Vitro Sensitivity Test in Antibiotics from the Fermentation Process in a Sugar-Alcohol Plant in the State of Paraná, Brazil

OpenAIRE

Lopes, Murilo Brandão; Faculdade de Apucarana – FAP; Silva, Thaís Medeiros Boldrin; Faculdade Metropolitana de Maringá – UNIFAMMA

2011-01-01

Since the development of different types of microorganisms is common during the fermentation process in sugar-alcohol plants, due to the processing states of prime matter, microbiological control is mandatory. In vitro sensitivity test is highly important for the fermentation process at sugar-alcohol plants since the type of antibiotic with the best antibacterial activity is evaluated. The test classifies antibiotics through their effects, namely, efficient, less efficient, slightly efficient...

Production of liquid transport fuel from cellulose material (wood). III Laboratory preparation of wood sugars and fermentation to ethanol and yeast

Energy Technology Data Exchange (ETDEWEB)

Whitworth, D A; Harwood, V D

1977-10-25

A laboratory procedure is described for hydrolyzing cellulose material to sugars by the use of hot sulfuric acid. The procedure has been used routinely for assessing raw materials. Raw materials used were radiata pine (fresh wood and decayed thinnings), pine needles, sawdust from old dumps, newspaper, cardboard, beech wood, and coconut wood. The neutralized sugar-liquors produced, supplemented with fertilizer grade nutrients, were fermented with bakers' yeast and gave near optimal conversion of hexoses to ethanol and of pentoses to protein biomass. From 100 g radiata pine (wood: bark mix 85:15) 25 ml (20 g) of ethanol and 2 g yeast biomass were routinely produced, although fermentation rates were lower than with pure sugars. The results, however, clearly showed that, by a hot dilute sulfure acid hydrolysis followed by a yeast fermentation process, cellulose resources avaliable in New Zealand are suitable for conversion to ethanol. 5 table, 1 figure.

Production of fermentable sugars by combined chemo-enzymatic hydrolysis of cellulosic material for bioethanol production

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M. Idrees

2014-06-01

Full Text Available To change the recalcitrant nature of the lignocellulosic material for maximum hydrolysis yield, a comprehensive study was done by using sulphuric acid as an exclusive catalyst for the pretreatment process. The enzymatic digestibility of the biomass [Water Hyacinth: Eichhornia crassipes] after pretreatment was determined by measuring the hydrolysis yield of the pretreated material obtained from twenty four different pretreatment conditions. These included different concentrations of sulphuric acid (0.0, 1.0, 2.0 and 3.0%, at two different temperatures (108 and 121 ºC for different residence times (1.0, 2.0 and 3.0h.The highest reducing sugar yield (36.65 g/L from enzymatic hydrolysis was obtained when plant material was pretreated at 121 ºC for 1.0 h residence time using 3.0% (v/v sulphuric acid and at 1:10 (w/v solid to liquid ratio. The total reducing sugars obtained from the two-stage process (pretreatment + enzymatic hydrolysis was 69.6g/L. The resulting sugars were fermented into ethanol by using Saccharomyces cerevisiae. The ethanol yield from the enzymatic hydrolyzate was 95.2% of the theoretical yield (0.51g/g glucose, as determined by GS-MS, and nearly 100% since no reducing sugars were detected in the fermenting media by TLC and DNS analysis.

D-Lactic acid biosynthesis from biomass-derived sugars via Lactobacillus delbrueckii fermentation.

Science.gov (United States)

Zhang, Yixing; Vadlani, Praveen V

2013-12-01

Poly-lactic acid (PLA) derived from renewable resources is considered to be a good substitute for petroleum-based plastics. The number of poly L-lactic acid applications is increased by the introduction of a stereocomplex PLA, which consists of both poly-L and D-lactic acid and has a higher melting temperature. To date, several studies have explored the production of L-lactic acid, but information on biosynthesis of D-lactic acid is limited. Pulp and corn stover are abundant, renewable lignocellulosic materials that can be hydrolyzed to sugars and used in biosynthesis of D-lactic acid. In our study, saccharification of pulp and corn stover was done by cellulase CTec2 and sugars generated from hydrolysis were converted to D-lactic acid by a homofermentative strain, L. delbrueckii, through a sequential hydrolysis and fermentation process (SHF) and a simultaneous saccharification and fermentation process (SSF). 36.3 g L(-1) of D-lactic acid with 99.8 % optical purity was obtained in the batch fermentation of pulp and attained highest yield and productivity of 0.83 g g(-1) and 1.01 g L(-1) h(-1), respectively. Luedeking-Piret model described the mixed growth-associated production of D-lactic acid with a maximum specific growth rate 0.2 h(-1) and product formation rate 0.026 h(-1), obtained for this strain. The efficient synthesis of D-lactic acid having high optical purity and melting point will lead to unique stereocomplex PLA with innovative applications in polymer industry.

Utilization of molasses and sugar cane bagasse for production of fungal invertase in solid state fermentation using Aspergillus niger GH1

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F. Veana

2014-06-01

Full Text Available Agro-industrial wastes have been used as substrate-support in solid state fermentation for enzyme production. Molasses and sugarcane bagasse are by-products of sugar industry and can be employed as substrates for invertase production. Invertase is an important enzyme for sweeteners development. In this study, a xerophilic fungus Aspergillus niger GH1 isolated of the Mexican semi-desert, previously reported as an invertase over-producer strain was used. Molasses from Mexico and Cuba were chemically analyzed (total and reducer sugars, nitrogen and phosphorous contents; the last one was selected based on chemical composition. Fermentations were performed using virgin and hydrolyzate bagasse (treatment with concentrated sulfuric acid. Results indicated that, the enzymatic yield (5231 U/L is higher than those reported by other A. niger strains under solid state fermentation, using hydrolyzate bagasse. The acid hydrolysis promotes availability of fermentable sugars. In addition, maximum invertase activity was detected at 24 h using low substrate concentration, which may reduce production costs. This study presents an alternative method for invertase production using a xerophilic fungus isolated from Mexican semi-desert and inexpensive substrates (molasses and sugarcane bagasse.

Utilization of molasses and sugar cane bagasse for production of fungal invertase in solid state fermentation using Aspergillus niger GH1

Science.gov (United States)

Veana, F.; Martínez-Hernández, J.L.; Aguilar, C.N.; Rodríguez-Herrera, R.; Michelena, G.

2014-01-01

Agro-industrial wastes have been used as substrate-support in solid state fermentation for enzyme production. Molasses and sugarcane bagasse are by-products of sugar industry and can be employed as substrates for invertase production. Invertase is an important enzyme for sweeteners development. In this study, a xerophilic fungus Aspergillus niger GH1 isolated of the Mexican semi-desert, previously reported as an invertase over-producer strain was used. Molasses from Mexico and Cuba were chemically analyzed (total and reducer sugars, nitrogen and phosphorous contents); the last one was selected based on chemical composition. Fermentations were performed using virgin and hydrolyzate bagasse (treatment with concentrated sulfuric acid). Results indicated that, the enzymatic yield (5231 U/L) is higher than those reported by other A. niger strains under solid state fermentation, using hydrolyzate bagasse. The acid hydrolysis promotes availability of fermentable sugars. In addition, maximum invertase activity was detected at 24 h using low substrate concentration, which may reduce production costs. This study presents an alternative method for invertase production using a xerophilic fungus isolated from Mexican semi-desert and inexpensive substrates (molasses and sugarcane bagasse). PMID:25242918

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

Science.gov (United States)

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

2015-08-01

Sugar beet pulp (SBP) has been investigated as a promising feedstock for ABE fermentation by Clostridium beijerinckii. Although lignin content in SBP is low, a pretreatment is needed to enhance enzymatic hydrolysis and fermentation yields. Autohydrolysis at pH 4 has been selected as the best pretreatment for SBP in terms of sugars release and acetone and butanol production. The best overall sugars release yields from raw SBP ranged from 66.2% to 70.6% for this pretreatment. The highest ABE yield achieved was 0.4g/g (5.1g/L of acetone and 6.6g/L butanol) and 143.2g ABE/kg SBP (62.3g acetone and 80.9g butanol) were obtained when pretreated SBP was enzymatically hydrolyzed at 7.5% (w/w) solid loading. Higher solid loadings (10%) offered higher acetone and butanol titers (5.8g/L of acetone and 7.8g/L butanol). All the experiments were carried out under not-controlling pH conditions reaching about 5.3 in the final samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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

2015-01-01

This study aims to improve enzymatic sugar production from dilute sulfuric acid-pretreated barley straw for acetone-butanol-ethanol (ABE) fermentation. The effects of additive xylanase and surfactants (polyethylene glycol [PEG] and Tween) in an enzymatic reaction system on straw hydrolysis yields were investigated. By combined application of 2g/100g dry-matter (DM) xylanase and PEG 4000, the glucose yield was increased from 53.2% to 86.9% and the xylose yield was increased from 36.2% to 70.2%, which were considerably higher than results obtained with xylanase or surfactant alone. The ABE fermentation of enzymatic hydrolysate produced 10.8 g/L ABE, in which 7.9 g/L was butanol. The enhanced sugar production increased the ABE yield from 93.8 to 135.0 g/kg pretreated straw. The combined application of xylanase and surfactants has a large potential to improve sugar production from barley straw pretreated with a mild acid and that the hydrolysate showed good fermentability in ABE production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of brown sugar and calcium superphosphate on the secondary fermentation of green waste.

Science.gov (United States)

Zhang, Lu; Sun, Xiangyang; Tian, Yun; Gong, Xiaoqiang

2013-03-01

The generation of green waste is increasing rapidly with population growth in China, and green waste is commonly treated by composting. The objective of this work was to study the physical and chemical characteristics of composted green waste as affected by a two-stage composting process and by the addition of brown sugar (at 0.0%, 0.5%, and 1%) and calcium superphosphate (Ca(H2PO4)2·H2O) (at 0%, 3%, and 6%) during the second stage. With or without these additives, all the composts displayed two peaks in fermentation temperature and matured in only 30days. Compared to traditional industrial composting, the composting method described here increased the duration of high-temperature fermentation period, reduced the maturity time, and reduced costs. Addition of 0.5% brown sugar plus 6% calcium superphosphate produced the highest quality compost with respect to C/N ratio, pH, organic matter content, electrical conductivity, particle-size distribution, and other characteristics. Copyright © 2012 Elsevier Ltd. All rights reserved.

Production of bioethanol from fermented sugars of sugarcane bagasse produced by lignocellulolytic enzymes of Exiguobacterium sp. VSG-1.

Science.gov (United States)

Vijayalaxmi, S; Anu Appaiah, K A; Jayalakshmi, S K; Mulimani, V H; Sreeramulu, K

2013-09-01

Exiguobacterium sp. VSG-1 was isolated from the soil sample and characterized for the production of lignocellulolytic enzymes. Production of these enzymes by the strain VSG-1 was carried out using steam-exploded sugarcane bagasse (SCB) and found to secrete cellulase, pectinase, mannanase, xylanase, and tannase. The growth and enzyme production were found to be optimum at pH 9.0 and 37 °C. Upon steam explosion of SCB, the cellulose increased by 42 %, whereas hemicelluloses and lignin decreased by 40 and 62 %, respectively. Enzymatic hydrolysis of steam-exploded SCB yielded 640 g/l of total sugars. Fermentation of sugars produced from pretreated SCB was carried out by using Saccharomyces cerevisiae at pH 5.0 and 30 °C. The alcohol produced was calculated and found to be 62.24 g/l corresponding to 78 % of the theoretical yield of ethanol. Hence, the strain VSG-1 has an industrial importance for the production of fermentable sugars for biofuels.

The Effect of Autochthonous Starter Culture, Sugars and Temperature on the Fermentation of Slavonian Kulen

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Krešimir Mastanjević

2017-01-01

Full Text Available In this study, the effect of an isolated and well-characterised autochthonous starter culture, glucose and maltodextrin (w=0.8 % and temperatures of 12 and 20 °C on fermentation and quality of Slavonian kulen produced using the traditional technology and recipe were investigated. Physicochemical and microbiological analyses were carried out after 20 days of fermentation. Upon the completion of the production process (90 days, a sensory analysis was carried out. Furthermore, pH value was continuously measured throughout the twenty-day fermentation period. The addition of an autochthonous starter culture and sugars and diff erent fermentation temperatures significantly (p<0.05 affected the instrumental colour and texture parameters of the Slavonian kulen. The fermentation was most intense in the samples with added autochthonous starter culture and 0.8 % glucose, and fermented at 20 °C. Microbiological analysis showed that samples with added autochthonous starter culture and fermented at higher temperature contained a higher number of lactic acid bacteria and coagulase-negative staphylococci and were safe. Sensory evaluation confirmed the outcomes of physicochemical and microbiological analyses and showed differences among samples fermented at two different temperatures and with added glucose or maltodextrin and an autochthonous starter culture.

Low pressure steam expansion pretreatment as a competitive approach to improve diosgenin yield and the production of fermentable sugar from Dioscorea zingiberensis C.H. Wright.

Science.gov (United States)

Wei, Mi; Tong, Yao; Wang, Hongbo; Wang, Lihua; Yu, Longjiang

2016-04-01

Development of efficient pretreatment methods which can disrupt the peripheral lignocellulose and even the parenchyma cells is of great importance for production of diosgenin from turmeric rhizomes. It was found that low pressure steam expansion pretreatment (LSEP) could improve the diosgenin yield by more than 40% compared with the case without pretreatment, while simultaneously increasing the production of fermentable sugar by 27.37%. Furthermore, little inhibitory compounds were produced in LSEP process which was extremely favorable for the subsequent biotransformation of fermentable sugar to other valuable products such as ethanol. Preliminary study showed that the ethanol yield when using the fermentable sugar as carbon source was comparable to that using glucose. The liquid residue of LSEP treated turmeric tuber after diosgenin production can be utilized as a quality fermentable carbon source. Therefore, LSEP has great potential in industrial application in diosgenin clean production and comprehensive utilization of turmeric tuber. Copyright © 2016 Elsevier Ltd. All rights reserved.

Environmental assessment of mild bisulfite pretreatment of forest residues into fermentable sugars for biofuel production.

Science.gov (United States)

Nwaneshiudu, Ikechukwu C; Ganguly, Indroneil; Pierobon, Francesca; Bowers, Tait; Eastin, Ivan

2016-01-01

Sugar production via pretreatment and enzymatic hydrolysis of cellulosic feedstock, in this case softwood harvest residues, is a critical step in the biochemical conversion pathway towards drop-in biofuels. Mild bisulfite (MBS) pretreatment is an emerging option for the breakdown and subsequent processing of biomass towards fermentable sugars. An environmental assessment of this process is critical to discern its future sustainability in the ever-changing biofuels landscape. The subsequent cradle-to-gate assessment of a proposed sugar production facility analyzes sugar made from woody biomass using MBS pretreatment across all seven impact categories (functional unit 1 kg dry mass sugar), with a specific focus on potential global warming and eutrophication impacts. The study found that the eutrophication impact (0.000201 kg N equivalent) is less than the impacts from conventional beet and cane sugars, while the global warming impact (0.353 kg CO2 equivalent) falls within the range of conventional processes. This work discusses some of the environmental impacts of designing and operating a sugar production facility that uses MBS as a method of treating cellulosic forest residuals. The impacts of each unit process in the proposed facility are highlighted. A comparison to other sugar-making process is detailed and will inform the growing biofuels literature.

Conversion of yellow crude sugar into alcohol. Conversion of yellow crude sugar in a mixture with sugar beet molasses

Energy Technology Data Exchange (ETDEWEB)

Krishtul, F B; Malchenko, A L; Poluyanova, M T; Gromovich, V F; Maskimova, E A; Golodovskaya, A I; Pal' gova, L S

1963-01-01

Crude sugar (96.5 to 98.4% sucrose) in a mixture with molasses can be converted into alcohol by either batchwise or continuous fermentation processes with good process characteristics. Best yields are obtained when the amount of crude sugar is not more than 50% of the total weight of fermenting material. The bakers' yeast and alcohol produced are of good quality.

An environmental life cycle assessment comparing Australian sugarcane with US corn and UK sugar beet as producers of sugars for fermentation

International Nuclear Information System (INIS)

Renouf, M.A.; Wegener, M.K.; Nielsen, L.K.

2008-01-01

Sugarcane is a highly suitable substrate for the production of bio-products. As well as producing high yields of sugar, much of the plant's fibre is also recovered and used as a source of renewable energy. A life cycle assessment (LCA) of sugarcane production and processing in Australia was performed to develop an environmental profile of sugarcane as a source of bio-products. The application examined was fermentation products from sugar. The sugarcane results were compared with results for other sugar producing crops-US corn and UK sugar beet-to gauge its relative environmental performance. The results show sugarcane to have an advantage in respect of energy input, greenhouse gas emissions and possibly acidification potential due to its high saccharide yield and the displacement of fossil fuels with surplus renewable energy from cane fibre (bagasse). However Australian sugarcane can exhibit high nitrous oxide emissions, which would reduce greenhouse gas advantages in some regions. For eutrophication, sugar beet provides advantages due to the avoided production of other agricultural crops displaced by the use of beet pulp as an animal feed. The three factors found to have the most influence on the environmental impacts of these agro-industrial systems were the commodities displaced by by-products, agricultural yields, and nitrogen use efficiency

An environmental life cycle assessment comparing Australian sugarcane with US corn and UK sugar beet as producers of sugars for fermentation

Energy Technology Data Exchange (ETDEWEB)

Renouf, M.A. [School of Geography, Planning and Architecture, The University of Queensland, Brisbane, QLD 4072 (Australia); CRC for Sugar Industry Innovation through Biotechnology, The University of Queensland, Brisbane, QLD 4072 (Australia); Wegener, M.K. [School of Natural and Rural Systems Management, The University of Queensland, QLD 4072 (Australia); CRC for Sugar Industry Innovation through Biotechnology, The University of Queensland, Brisbane, QLD 4072 (Australia); Nielsen, L.K. [Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072 (Australia); CRC for Sugar Industry Innovation through Biotechnology, The University of Queensland, Brisbane, QLD 4072 (Australia)

2008-12-15

Sugarcane is a highly suitable substrate for the production of bio-products. As well as producing high yields of sugar, much of the plant's fibre is also recovered and used as a source of renewable energy. A life cycle assessment (LCA) of sugarcane production and processing in Australia was performed to develop an environmental profile of sugarcane as a source of bio-products. The application examined was fermentation products from sugar. The sugarcane results were compared with results for other sugar producing crops - US corn and UK sugar beet - to gauge its relative environmental performance. The results show sugarcane to have an advantage in respect of energy input, greenhouse gas emissions and possibly acidification potential due to its high saccharide yield and the displacement of fossil fuels with surplus renewable energy from cane fibre (bagasse). However Australian sugarcane can exhibit high nitrous oxide emissions, which would reduce greenhouse gas advantages in some regions. For eutrophication, sugar beet provides advantages due to the avoided production of other agricultural crops displaced by the use of beet pulp as an animal feed. The three factors found to have the most influence on the environmental impacts of these agro-industrial systems were the commodities displaced by by-products, agricultural yields, and nitrogen use efficiency. (author)

BUSINESS OPPORTUNITIES OF CITRIC ACID PRODUCTION BY FERMENTATION FROM SUGAR SUBSTRATES IN CUBA

Directory of Open Access Journals (Sweden)

Omar Pérez Navarro

2016-04-01

Full Text Available A proposal for opportunities of citric acid production in Cuba, using sources of sugar substrates such as refined sugar, molasses and whey, by submerged fermentation with Aspergillus niger, where a technology is established from the selected substrate which is provided and the microorganism used. This is a demanding process in terms of investment costs and operation where the best combinations of productivity and cost are achieved with molasses followed by refined sugar and whey. For the selected substrate, the mass and energy balance in each of the steps in the process of obtaining citric acid for different productive capacities of citric acid was made and the minimum economic size of 2.5 t / day was determined. A production capacity of 8 t / day of granulated acid (2 640 t / a, with estimated total investment of $ 9,068,713, NPV = $ 1,401,561, IRR = 27% and DPP = 3 years was selected. The project is resistant to the rising price of raw materials and the cost of electricity and is favored when the process is integrated into a sugar mill cogeneration, while it is sensitive to a reduction in the selling price of the product.

Tailoring Wet Explosion Process Parameters for the Pretreatment of Cocksfoot Grass for High Sugar Yields

DEFF Research Database (Denmark)

Njoku, Stephen Ikechukwu; Ahring, Birgitte Kiær; Uellendahl, Hinrich

2013-01-01

The pretreatment of lignocellulosic biomass is crucial for efficient subsequent enzymatic hydrolysis and ethanol fermentation. In this study, wet explosion (WEx) pretreatment was applied to cocksfoot grass and pretreatment conditions were tailored for maximizing the sugar yields using response...... glucose release with low formation of by-products. Under these conditions, the cellulose and hemicellulose sugar recovery was 94 % and 70 %, respectively. The efficiency of the enzymatic hydrolysis of cellulose under these conditions was 91 %. On the other hand, the release of pentose sugars was higher...... when applying less severe pretreatment conditions C (160 °C, 5 min, 0.2 % dilute sulfuric acid). Therefore, the choice of the most suitable pretreatment conditions is depending on the main target product, i.e., hexose or pentose sugars....

Growth and ethanol fermentation ability on hexose and pentose sugars and glucose effect under various conditions in thermotolerant yeast Kluyveromyces marxianus.

Science.gov (United States)

Rodrussamee, Nadchanok; Lertwattanasakul, Noppon; Hirata, Katsushi; Suprayogi; Limtong, Savitree; Kosaka, Tomoyuki; Yamada, Mamoru

2011-05-01

Ethanol fermentation ability of the thermotolerant yeast Kluyveromyces marxianus, which is able to utilize various sugars including glucose, mannose, galactose, xylose, and arabinose, was examined under shaking and static conditions at high temperatures. The yeast was found to produce ethanol from all of these sugars except for arabinose under a shaking condition but only from hexose sugars under a static condition. Growth and sugar utilization rate under a static condition were slower than those under a shaking condition, but maximum ethanol yield was slightly higher. Even at 40°C, a level of ethanol production similar to that at 30°C was observed except for galactose under a static condition. Glucose repression on utilization of other sugars was observed, and it was more evident at elevated temperatures. Consistent results were obtained by the addition of 2-deoxyglucose. The glucose effect was further examined at a transcription level, and it was found that KmGAL1 for galactokinase and KmXYL1 for xylose reductase for galactose and xylose/arabinose utilization, respectively, were repressed by glucose at low and high temperatures, but KmHXK2 for hexokinase was not repressed. We discuss the possible mechanism of glucose repression and the potential for utilization of K. marxianus in high-temperature fermentation with mixed sugars containing glucose.

Growth and ethanol fermentation ability on hexose and pentose sugars and glucose effect under various conditions in thermotolerant yeast Kluyveromyces marxianus

Energy Technology Data Exchange (ETDEWEB)

Rodrussamee, Nadchanok; Hirata, Katsushi; Suprayogi [Yamaguchi Univ., Ube (Japan). Graduate School of Medicine; Lertwattanasakul, Noppon; Kosaka, Tomoyuki [Yamaguchi Univ. (Japan). Faculty of Agriculture; Limtong, Savitree [Kasetsart Univ., Bangkok (Thailand). Faculty of Science; Yamada, Mamoru [Yamaguchi Univ., Ube (Japan). Graduate School of Medicine; Yamaguchi Univ. (Japan). Faculty of Agriculture

2011-05-15

Ethanol fermentation ability of the thermotolerant yeast Kluyveromyces marxianus, which is able to utilize various sugars including glucose, mannose, galactose, xylose, and arabinose, was examined under shaking and static conditions at high temperatures. The yeast was found to produce ethanol from all of these sugars except for arabinose under a shaking condition but only from hexose sugars under a static condition. Growth and sugar utilization rate under a static condition were slower than those under a shaking condition, but maximum ethanol yield was slightly higher. Even at 40 C, a level of ethanol production similar to that at 30 C was observed except for galactose under a static condition. Glucose repression on utilization of other sugars was observed, and it was more evident at elevated temperatures. Consistent results were obtained by the addition of 2-deoxyglucose. The glucose effect was further examined at a transcription level, and it was found that KmGAL1 for galactokinase and KmXYL1 for xylose reductase for galactose and xylose/arabinose utilization, respectively, were repressed by glucose at low and high temperatures, but KmHXK2 for hexokinase was not repressed. We discuss the possible mechanism of glucose repression and the potential for utilization of K. marxianus in high-temperature fermentation with mixed sugars containing glucose. (orig.)

Modeling of acetate-type fermentation of sugar-containing wastewater under acidic pH conditions.

Science.gov (United States)

Huang, Liang; Pan, Xin-Rong; Wang, Ya-Zhou; Li, Chen-Xuan; Chen, Chang-Bin; Zhao, Quan-Bao; Mu, Yang; Yu, Han-Qing; Li, Wen-Wei

2018-01-01

In this study, a kinetic model was developed based on Anaerobic Digestion Model No. 1 to provide insights into the directed production of acetate and methane from sugar-containing wastewater under low pH conditions. The model sufficiently described the dynamics of liquid-phase and gaseous products in an anaerobic membrane bioreactor by comprehensively considering the syntrophic bioconversion steps of sucrose hydrolysis, acidogenesis, acetogenesis and methanogenesis under acidic pH conditions. The modeling results revealed a significant pH-dependency of hydrogenotrophic methanogenesis and ethanol-producing processes that govern the sucrose fermentative pathway through changing the hydrogen yield. The reaction thermodynamics of such acetate-type fermentation were evaluated, and the implications for process optimization by adjusting the hydraulic retention time were discussed. This work sheds light on the acid-stimulated acetate-type fermentation process and may lay a foundation for optimization of resource-oriented processes for treatment of food wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Draft Genome Sequence of Lactobacillus farciminis NBRC 111452, Isolated from K?so, a Japanese Sugar-Vegetable Fermented Beverage

OpenAIRE

Chiou, Tai-Ying; Oshima, Kenshiro; Suda, Wataru; Hattori, Masahira; Takahashi, Tomoya

2016-01-01

Here, we report the draft genome sequence of the Lactobacillus farciminis strain NBRC 111452, isolated from k?so, a Japanese sugar-vegetable fermented beverage. This genome information is of potential use in studies of Lactobacillus farciminis as a probiotic.

[Effect of products of thermophilous methane fermentation on the fermentation of fruit must by Saccharomyces vini].

Science.gov (United States)

Mikhlin, E D; Kotomina, E N; Pisarnitsky

1975-01-01

Experiments were carried out to study the effect of extracts from products of thermophilous methane fermentation at a dose of 0.7+2.0 ml/100 ml on the proliferation and fermentation activity of yeast Saccharomyces vini of the Yablochnaya-7 and Vishnevaya-33 race during their cultivation in the Hansen medium and in the apple and cranberry must with a normal and elevated content of sugar and acid. In some experiments the must was enriched in (NH4)2HPO4 at a dose of 0.3 g/l. Additions of small amounts of products of thermophilous methane fermentation accelerated fermentation of fruit musts with a normal sugar content and to a greater extent musts with an increased sugar content (27%). In the must enriched in (NH4)2HPO4 an almost complete (over 98%) fermentation of sugar developed for 27 days. In the must with an increased acidity (due to citric acid added to bring titrable acidity to 25 g/l) additions of the preparation also accerlerated the begining of the fermentation and increased its intensity.

EFFECT OF NITROGEN SOURCE AND INITIAL SUGAR CONCENTRATION ON LACTIC ACID FERMENTATION OF PINEAPPLE WASTE USING L.DELBRUECKII

Directory of Open Access Journals (Sweden)

Abdullah Moch Busairi

2012-02-01

Full Text Available The liquid pineapple waste contains mainly sucrose, glucose, fructose and other nutrients. It therefore can potentially be used as carbon source for lactic acid fermentation. The lactic acid is utilised in food technology as pH regulator, microbial preservative, buffering agent and in the chemical industry. Recently, lactic acid has been considered to be an important raw material for production of biodegradable lactate polymer. The experiments were carried out in batch fermentation at anaerobic condition with stirring speed: 50 rpm, temperature: 40 oC, pH: 6.0, and inoculum size: 5%. Effect of nitrogen source and initial sugar concentration were studied. The effect of nitrogen source on lactic acid production shows that the yeast extract is highest yield , followed by urea , corn steep liquor, malt sprout and ammonium sulphates with the yield of 78.52; 26.68; 19.14; 14.10 and 5.6 %, respectively. The highest yield of initial sugar concentration on lactic acid production obtained was 78.52 % (54.97 g/l at 70 g/l, if the concentration of sugar was increased to 110 g/l , the lactic acid production or yield decrease to51.53 g/l or 54.24%.

Multi-stage continuous alcohol fermentation with cane molasses

Energy Technology Data Exchange (ETDEWEB)

Chu, C J; Chiou, C J; Ng, A K; Lin, T C; Hwang, E C; Rao, C H

1970-01-01

It was reported that 6 to 7% ethanol was produced by single-stage continuous 12-hour cycle fermentation of molasses containing 12% sugar using a new strain, Saccharomyces formensensis, isolated from a stock culture. A higher yield of ethanol was obtained from 2-stage and 3-stage continuous fermentation of molasses containing more sugar at 24- and 36-hour cycles, respectively. In the 2-stage 24-hour cycle continuous fermentation of molasses containing 15% sugar with an agitation speed 300 rpm, 9.2% ethanol resulted. Only 3% sugar remained unconsumed. In the 3-stage 36-hour cycle continuous fermentation of molasses containing 15% sugar with 300 rpm agitation, 12.5% ethanol resulted.

IN VITRO FERMENTATION EFFICIENCY OF MIXTURES OF Cynodon nlemfuensis, Leucaena leucocephala AND TWO ENERGY SOURCES (MAIZE OR SUGAR CANE MOLASSES

Directory of Open Access Journals (Sweden)

Juan Martin Estrada-Liévano

2009-07-01

Full Text Available The in vitro fermentation efficiency of Cynodon nlemfuensis forage (star grass and Leucaena leucocephala foliage (leucaena and two energy sources (i.e. maize and sugar cane molasses mixture was evaluated. Mixture samples (1 g DM were incubated for 24 h. All the mixtures were added with 500 mg of polyetilenglycol (PEG. Adding molasses to star grass increased dry matter true digestibility and carbohydrate fermentation (P

Acid-producing capacity from sugars and sugar alcohols among Lactobacillus isolates collected in connection with radiation therapy.

Science.gov (United States)

Almståhl, Annica; Rudbäck, Helena; Basic, Amina; Carlén, Anette; Alstad, Torgny

2017-12-01

To investigate the acid-producing capacity from sugars and sugar alcohols of oral Lactobacillus collected in connection with radiation therapy (RT) to the head and neck region. Lactobacillus were collected from the tongue, buccal mucosa and supragingival plaque in 24 patients before, during, and after RT. The acid-producing capacity of Lactobacillus isolates (n=211) was analyzed using a colorimetric fermentation test in microtiter plates. Solutions containing 2% sugars (sucrose, glucose, fructose, lactose) or sugar-alcohols (sorbitol and xylitol) were used. After 24h of incubation, bacterial acid-producing capacity was determined as strong (pH6). Data regarding intake frequency of sugar-rich products and products with sugar-alcohols was collected. The highest acid-producing capacity using the sugars was seen for isolates collected during RT. Sorbitol was fermented to a higher extent during and post RT, especially among isolates from plaque. Lactobacillus fermenting xylitol showed the highest acid-producing capacity during RT (psugar-rich products or sugar-alcohol containing products and Lactobacillus acid-producing capacity, were found. The results suggest that Lactobacillus isolates, collected from the tongue, buccal mucosa and supragingival plaque, have a higher acid-producing capacity using sugars and sugar-alcohols during RT than one year post RT. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative technoeconomic analysis of a softwood ethanol process featuring posthydrolysis sugars concentration operations and continuous fermentation with cell recycle.

Science.gov (United States)

Schneiderman, Steven J; Gurram, Raghu N; Menkhaus, Todd J; Gilcrease, Patrick C

2015-01-01

Economical production of second generation ethanol from Ponderosa pine is of interest due to widespread mountain pine beetle infestation in the western United States and Canada. The conversion process is limited by low glucose and high inhibitor concentrations resulting from conventional low-solids dilute acid pretreatment and enzymatic hydrolysis. Inhibited fermentations require larger fermentors (due to reduced volumetric productivity) and low sugars lead to low ethanol titers, increasing distillation costs. In this work, multiple effect evaporation (MEE) and nanofiltration (NF) were evaluated to concentrate the hydrolysate from 30 g/l to 100, 150, or 200 g/l glucose. To ferment this high gravity, inhibitor containing stream, traditional batch fermentation was compared with continuous stirred tank fermentation (CSTF) and continuous fermentation with cell recycle (CSTF-CR). Equivalent annual operating cost (EAOC = amortized capital + yearly operating expenses) was used to compare these potential improvements for a local-scale 5 MGY ethanol production facility. Hydrolysate concentration via evaporation increased EAOC over the base process due to the capital and energy intensive nature of evaporating a very dilute sugar stream; however, concentration via NF decreased EAOC for several of the cases (by 2 to 15%). NF concentration to 100 g/l glucose with a CSTF-CR was the most economical option, reducing EAOC by $0.15 per gallon ethanol produced. Sensitivity analyses on NF options showed that EAOC improvement over the base case could still be realized for even higher solids removal requirements (up to two times higher centrifuge requirement for the best case) or decreased NF performance. © 2015 American Institute of Chemical Engineers.

Novel DDR Processing of Corn Stover Achieves High Monomeric Sugar Concentrations from Enzymatic Hydrolysis (230 g/L) and High Ethanol Concentration (10% v/v) During Fermentation

Energy Technology Data Exchange (ETDEWEB)

Chen, Xiaowen; Jennings, Ed; Shekiro, Joe; Kuhn, Erik M.; O' Brien, Marykate; Wang, Wei; Schell, Daniel J.; Himmel, Mike; Elander, Richard T.; Tucker, Melvin P.

2015-04-03

Distilling and purifying ethanol, butanol, and other products from second and later generation lignocellulosic biorefineries adds significant capital and operating cost for biofuels production. The energy costs associated with distillation affects plant gate and life cycle analysis costs. Lower titers in fermentation due to lower sugar concentrations from pretreatment increase both energy and production costs. In addition, higher titers decrease the volumes required for enzymatic hydrolysis and fermentation vessels. Therefore, increasing biofuels titers has been a research focus in renewable biofuels production for several decades. In this work, we achieved over 200 g/L of monomeric sugars after high solids enzymatic hydrolysis using the novel deacetylation and disc refining (DDR) process on corn stover. The high sugar concentrations and low chemical inhibitor concentrations from the DDR process allowed ethanol titers as high as 82 g/L in 22 hours, which translates into approximately 10 vol% ethanol. To our knowledge, this is the first time that 10 vol% ethanol in fermentation derived from corn stover without any sugar concentration or purification steps has been reported. Techno-economic analysis shows the higher titer ethanol achieved from the DDR process could significantly reduce the minimum ethanol selling price from cellulosic biomass.

Effect of sugar fatty acid esters on rumen fermentation in vitro.

Science.gov (United States)

Wakita, M; Hoshino, S

1987-11-01

1. The effect of sugar fatty acid esters (SFEs; currently used as food additives for human consumption) on rumen volatile fatty acids (VFA) and gas production was studied with sheep rumen contents in vitro. 2. Some SFEs having monoester contents of more than 70% increased the molar proportion of propionate in conjunction with reduction in the acetate:propionate ratio when the individual SFE was added to rumen contents in a final concentration of 4 g/l. Laurate sugar ester was the most potent propionate enhancer and rumen gas depressor, the effective dose being as low as 1 g/l in a final concentration. Fatty acid esters other than SFEs had little, if any, effect on rumen VFA production and their molar proportions. 3. Approximately 50% of laurate sugar ester was hydrolysed by in vitro incubation with rumen fluid for 2 h. The addition of fatty acids and sucrose was also effective in the alterations of rumen VFA and gas production. However, the effect of SFEs on in vitro rumen fermentation was significantly greater than that of their constituent fatty acids or sucrose, or both. Accordingly, the effect appeared to be ascribed to the complex action of SFE itself and to its constituents, free fatty acids and sucrose. 4. SFEs, at the level of 4 g/l, reduced substantially the froth formation (ingesta volume increase) and seemed to be effective for the prevention of bloat.

Respiration-dependent utilization of sugars in yeasts: a determinant role for sugar transporters.

Science.gov (United States)

Goffrini, Paola; Ferrero, Iliana; Donnini, Claudia

2002-01-01

In many yeast species, including Kluyveromyces lactis, growth on certain sugars (such as galactose, raffinose, and maltose) occurs only under respiratory conditions. If respiration is blocked by inhibitors, mutation, or anaerobiosis, growth does not take place. This apparent dependence on respiration for the utilization of certain sugars has often been suspected to be associated with the mechanism of the sugar uptake step. We hypothesized that in many yeast species, the permease activities for these sugars are not sufficient to ensure the high substrate flow that is necessary for fermentative growth. By introducing additional sugar permease genes, we have obtained K. lactis strains that were capable of growing on galactose and raffinose in the absence of respiration. High dosages of both the permease and maltase genes were indeed necessary for K. lactis cells to grow on maltose in the absence of respiration. These results strongly suggest that the sugar uptake step is the major bottleneck in the fermentative assimilation of certain sugars in K. lactis and probably in many other yeasts.

Mathematical model of CO2 release during milk fermentation using natural kefir grains.

Science.gov (United States)

Goršek, Andreja; Ritonja, Jožef; Pečar, Darja

2018-03-12

Milk fermentation takes place in the presence of various micro-organisms, producing a variety of dairy products. The oldest of them is kefir, which is usually produced by the fermentation of milk with kefir grains. Carbon dioxide (CO 2 ), as one of the process products, also contributes to the characteristic flavor of kefir. The amount of CO 2 generated during fermentation depends on bioprocessing conditions and may change, which is not desirable at the industrial level. In this study we developed a simplified mathematical model of CO 2 release in the milk-fermentation process. An intuitive approach based on superposition and experimental analysis was used for the modeling. The chemical system studied was considered as a two-input (temperature, rotational frequency of the stirrer) one-output (CO 2 concentration) dynamic system. Based on an analysis of CO 2 release transients in the case of non-simultaneous stepwise changed input quantities, two differential equations were defined that describe the influence of the two input quantities on the output quantity. The simulation results were verified by experiments. The proposed model can be used for a comprehensive analysis of the process that is being studied and for the design and synthesis of advanced control systems, which will ensure a controlled CO 2 release at the industrial level. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Kinetics of growth and sugar consumption in yeasts.

Science.gov (United States)

van Dijken, J P; Weusthuis, R A; Pronk, J T

1993-01-01

An overview is presented of the steady- and transient state kinetics of growth and formation of metabolic byproducts in yeasts. Saccharomyces cerevisiae is strongly inclined to perform alcoholic fermentation. Even under fully aerobic conditions, ethanol is produced by this yeast when sugars are present in excess. This so-called 'Crabtree effect' probably results from a multiplicity of factors, including the mode of sugar transport and the regulation of enzyme activities involved in respiration and alcoholic fermentation. The Crabtree effect in S. cerevisiae is not caused by an intrinsic inability to adjust its respiratory activity to high glycolytic fluxes. Under certain cultivation conditions, for example during growth in the presence of weak organic acids, very high respiration rates can be achieved by this yeast. S. cerevisiae is an exceptional yeast since, in contrast to most other species that are able to perform alcoholic fermentation, it can grow under strictly anaerobic conditions. 'Non-Saccharomyces' yeasts require a growth-limiting supply of oxygen (i.e. oxygen-limited growth conditions) to trigger alcoholic fermentation. However, complete absence of oxygen results in cessation of growth and therefore, ultimately, of alcoholic fermentation. Since it is very difficult to reproducibly achieve the right oxygen dosage in large-scale fermentations, non-Saccharomyces yeasts are therefore not suitable for large-scale alcoholic fermentation of sugar-containing waste streams. In these yeasts, alcoholic fermentation is also dependent on the type of sugar. For example, the facultatively fermentative yeast Candida utilis does not ferment maltose, not even under oxygen-limited growth conditions, although this disaccharide supports rapid oxidative growth.

Fermentation value of molasses for the alcohol industry

Energy Technology Data Exchange (ETDEWEB)

Sobkiewicz, G

1963-01-01

Molasses of pH 7 to 8 containing invert sugar in quantity not exceeding 1% showed the highest fermentation value. The purity coefficient should not exceed 56%, since non-sugars, minerals, and nitrogen compounds stimulated fermentation.

Cellulolytic enzyme expression and simultaneous conversion of lignocellulosic sugars into ethanol and xylitol by a new Candida tropicalis strain.

Science.gov (United States)

Mattam, Anu Jose; Kuila, Arindam; Suralikerimath, Niranjan; Choudary, Nettem; Rao, Peddy V C; Velankar, Harshad Ravindra

2016-01-01

Lignocellulosic ethanol production involves major steps such as thermochemical pretreatment of biomass, enzymatic hydrolysis of pre-treated biomass and the fermentation of released sugars into ethanol. At least two different organisms are conventionally utilized for producing cellulolytic enzymes and for ethanol production through fermentation, whereas in the present study a single yeast isolate with the capacity to simultaneously produce cellulases and xylanases and ferment the released sugars into ethanol and xylitol has been described. A yeast strain isolated from soil samples and identified as Candida tropicalis MTCC 25057 expressed cellulases and xylanases over a wide range of temperatures (32 and 42 °C) and in the presence of different cellulosic substrates [carboxymethylcellulose and wheat straw (WS)]. The studies indicated that the cultivation of yeast at 42 °C in pre-treated hydrolysate containing 0.5 % WS resulted in proportional expression of cellulases (exoglucanases and endoglucanases) at concentrations of 114.1 and 97.8 U g(-1) ds, respectively. A high xylanase activity (689.3 U g(-1) ds) was also exhibited by the yeast under similar growth conditions. Maximum expression of cellulolytic enzymes by the yeast occurred within 24 h of incubation. Of the sugars released from biomass after pretreatment, 49 g L(-1) xylose was aerobically converted into 15.8 g L(-1) of xylitol. In addition, 25.4 g L(-1) glucose released after the enzymatic hydrolysis of biomass was fermented by the same yeast to obtain an ethanol titer of 7.3 g L(-1). During the present study, a new strain of C. tropicalis was isolated and found to have potential for consolidated bioprocessing (CBP) applications. The strain could grow in a wide range of process conditions (temperature, pH) and in the presence of lignocellulosic inhibitors such as furfural, HMF and acetic acid. The new yeast produced cellulolytic enzymes over a wide temperature range and in the presence of

Pretreatment of Dried Distiller Grains with Solubles by Soaking in Aqueous Ammonia and Subsequent Enzymatic/Dilute Acid Hydrolysis to Produce Fermentable Sugars.

Science.gov (United States)

Nghiem, Nhuan P; Montanti, Justin; Kim, Tae Hyun

2016-05-01

Dried distillers grains with solubles (DDGS), a co-product of corn ethanol production in the dry-grind process, was pretreated by soaking in aqueous ammonia (SAA) using a 15 % w/w NH4OH solution at a solid/liquid ratio of 1:10. The effect of pretreatment on subsequent enzymatic hydrolysis was studied at two temperatures (40 and 60 °C) and four reaction times (6, 12, 24, and 48 h). Highest glucose yield of 91 % theoretical was obtained for the DDGS pretreated at 60 °C and 24 h. The solubilized hemicellulose in the liquid fraction was further hydrolyzed with dilute H2SO4 to generate fermentable monomeric sugars. The conditions of acid hydrolysis included 1 and 4 wt% acid, 60 and 120 °C, and 0.5 and 1 h. Highest yields of xylose and arabinose were obtained at 4 wt% acid, 120 °C, and 1 h. The fermentability of the hydrolysate obtained by enzymatic hydrolysis of the SAA-pretreated DDGS was demonstrated in ethanol fermentation by Saccharomyces cerevisiae. The fermentability of the hydrolysate obtained by consecutive enzymatic and dilute acid hydrolysis was demonstrated using a succinic acid-producing microorganism, strain Escherichia coli AFP184. Under the fermentation conditions, complete utilization of glucose and arabinose was observed, whereas only 47 % of xylose was used. The succinic acid yield was 0.60 g/g total sugar consumed.

Lactic acid production from biomass-derived sugars via co-fermentation of Lactobacillus brevis and Lactobacillus plantarum.

Science.gov (United States)

Zhang, Yixing; Vadlani, Praveen V

2015-06-01

Lignocellulosic biomass is an attractive alternative resource for producing chemicals and fuels. Xylose is the dominating sugar after hydrolysis of hemicellulose in the biomass, but most microorganisms either cannot ferment xylose or have a hierarchical sugar utilization pattern in which glucose is consumed first. To overcome this barrier, Lactobacillus brevis ATCC 367 was selected to produce lactic acid. This strain possesses a relaxed carbon catabolite repression mechanism that can use glucose and xylose simultaneously; however, lactic acid yield was only 0.52 g g(-1) from a mixture of glucose and xylose, and 5.1 g L(-1) of acetic acid and 8.3 g L(-1) of ethanol were also formed during production of lactic acid. The yield was significantly increased and ethanol production was significantly reduced if L. brevis was co-cultivated with Lactobacillus plantarum ATCC 21028. L. plantarum outcompeted L. brevis in glucose consumption, meaning that L. brevis was focused on converting xylose to lactic acid and the by-product, ethanol, was reduced due to less NADH generated in the fermentation system. Sequential co-fermentation of L. brevis and L. plantarum increased lactic acid yield to 0.80 g g(-1) from poplar hydrolyzate and increased yield to 0.78 g lactic acid per g of biomass from alkali-treated corn stover with minimum by-product formation. Efficient utilization of both cellulose and hemicellulose components of the biomass will improve overall lactic acid production and enable an economical process to produce biodegradable plastics. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Ethyl alcohol by fermentation

Energy Technology Data Exchange (ETDEWEB)

1952-02-13

Ethanol is made from solutions poor in sugar and free of yeast carriers, e.g. from whey, by fermentation under sterile conditions. The CO/sub 2/ formed in the decomposition of sugar is used as an agitating medium to ensure good contact between the yeast and the sugar.

Sugar catabolism during growth on plant biomass in Aspergillus

NARCIS (Netherlands)

Khosravi, C.

2017-01-01

A growing industrial sector in which plant degrading enzymes are used is the production of alternative fuels, such as bio-ethanol, and biochemicals. Plant polysaccharides can be converted to fermentable sugars by fungal enzymes. The sugars are then fermented to ethanol and other products mainly by

Enhancing phosphorus release from waste activated sludge containing ferric or aluminum phosphates by EDTA addition during anaerobic fermentation process.

Science.gov (United States)

Zou, Jinte; Zhang, Lili; Wang, Lin; Li, Yongmei

2017-03-01

The effect of ethylene diamine tetraacetic acid (EDTA) addition on phosphorus release from biosolids and phosphate precipitates during anaerobic fermentation was investigated. Meanwhile, the impact of EDTA addition on the anaerobic fermentation process was revealed. The results indicate that EDTA addition significantly enhanced the release of phosphorus from biosolids, ferric phosphate precipitate and aluminum phosphate precipitate during anaerobic fermentation, which is attributed to the complexation of metal ions and damage of cell membrane caused by EDTA. With the optimal EDTA addition of 19.5 mM (0.41 gEDTA/gSS), phosphorus release efficiency from biosolids was 82%, which was much higher than that (40%) without EDTA addition. Meanwhile, with 19.5 mM EDTA addition, almost all the phosphorus in ferric phosphate precipitate was released, while only 57% of phosphorus in aluminum phosphate precipitate was released. This indicates that phosphorus in ferric phosphate precipitate was much easier to be released than that in aluminum phosphate precipitate during anaerobic fermentation of sludge. In addition, proper EDTA addition facilitated the production of soluble total organic carbon and volatile fatty acids, as well as solid reduction during sludge fermentation, although methane production could be inhibited. Therefore, EDTA addition can be used as an alternative method for recovering phosphorus from waste activated sludge containing ferric or aluminum precipitates, as well as recovery of soluble carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fermentation of Arabinoxylan-Oligosaccharides, Oligofructose and their Monomeric Sugars by Hindgut Bacteria from Siberian Sturgeon and African Catfish in Batch Culture in vitro

NARCIS (Netherlands)

Geraylou, Z.; Rurangwa, E.; Wiele, van der T.; Courtin, C.M.; Delcour, J.A.; Buyse, J.; Ollevier, F.

2014-01-01

The in vitro fermentation of two Non-Digestible Oligosaccharide (NDO) preparations, Arabinoxylan- Oligosaccharides (AXOS) and Oligofructose (OF), and their respective monomeric sugars, xylose and fructose, were investigated by hindgut microbiota of two major aquaculture fish species, Siberian

Continuous alcoholic fermentation of blackstrap molasses

Energy Technology Data Exchange (ETDEWEB)

Borzani, W; Aquarone, E

1957-01-01

The sugar concentration and the fermentation-cycle time can be related by an equation, theoretically justified, if it is assumed that the sugar consumption has a reaction rate of -1. Agitation is probably the rate-determining factor for continous alcohol fermentation. Penicillin increases the efficiency by preventing contamination. After 30 hours of fermentation, the penicillin concentration was 25 to 60% of the initial antibiotic concentration. Laboratory and plant-scale fermentations with 1.0 unit/ml of penicillin were studied and found favorable. An increase in the alcohol yield (4.8 to 19.5%) and a reduction of the acid production (17.0 to 66.6%) were observed. Penicillin did not affect the final yeast count or the fermentation time, and Leuconostoc contamination was inhibited by 8.0 units/ml.

A Mathematical Model for Simultaneous Saccharification and Co-fermentation (SSCF) of C6 and C5 Sugars

DEFF Research Database (Denmark)

Morales Rodriguez, Ricardo; Gernaey, Krist; Meyer, Anne S.

2011-01-01

saccharification and co-fermentation (SSCF) of C6 and C5 sugars. The model is constructed by combining existing mathematical models for enzymatic hydrolysis and co-fermentation. An inhibition of ethanol on cellulose conversion is introduced in order to increase the reliability. The mathematical model for the SSCF...... is verified by comparing the model predictions with experimental data obtained from the ethanol production based on kraft paper mill sludge. When fitting the model to the data, only the yield coefficients for glucose and xylose metabolism were fine-tuned, which were found to be 0.43 g·g−1 (ethanol....../glucose) and 0.35 g·g−1 (ethanol/xylose) respectively. These promising validation results encourage further model application to evaluate different process configurations for lignocellulosic bioethanol technology....

Sugar utilization patterns and respiro-fermentative metabolism in the baker's yeast Torulaspora delbrueckii.

Science.gov (United States)

Alves-Araújo, C; Pacheco, A; Almeida, M J; Spencer-Martins, I; Leão, C; Sousa, M J

2007-03-01

The highly osmo- and cryotolerant yeast species Torulaspora delbrueckii is an important case study among the non-Saccharomyces yeast species. The strain T. delbrueckii PYCC 5321, isolated from traditional corn and rye bread dough in northern Portugal, is considered particularly interesting for the baking industry. This paper reports the sugar utilization patterns of this strain, using media with glucose, maltose and sucrose, alone or in mixtures. Kinetics of growth, biomass and ethanol yields, fermentation and respiration rates, hydrolase activities and sugar uptake rates were used to infer the potential applied relevance of this yeast in comparison to a conventional baker's strain of Saccharomyces cerevisiae. The results showed that both maltase and maltose transport in T. delbrueckii were subject to glucose repression and maltose induction, whereas invertase was subject to glucose control but not dependent on sucrose induction. A comparative analysis of specific sugar consumption rates and transport capacities suggests that the transport step limits both glucose and maltose metabolism. Specific rates of CO(2) production and O(2) consumption showed a significantly higher contribution of respiration to the overall metabolism in T. delbrueckii than in S. cerevisiae. This was reflected in the biomass yields from batch cultures and could represent an asset for the large-scale production of the former species. This work contributes to a better understanding of the physiology of a non-conventional yeast species, with a view to the full exploitation of T. delbrueckii by the baking industry.

Content of sugar, organic acids and ethanol in fermented milk beverages obtained with different types of kombucha inoculum

Directory of Open Access Journals (Sweden)

Iličić Mirela D.

2017-01-01

Full Text Available The aim of this study was to examine the influence of different types and concentration of kombucha inoculum on content of sugar, organic acids and ethanol in the fermented beverages produced from milk of 0.9% fat content. Three different kombucha inoculums, cultivated on black tea with addition of sucrose: standard inoculum - 10% (w/w and 15% (w/w, concentrated by microfiltration- 10% (w/w and 15% (w/w, and concentrated by evaporation - 1.5% (w/w and 3.0% (w/w, were applied in the manufacture of fermented milk. Contents of lactose, galactose, glucose, fructose, organic acids, and ethanol in the kombuha fermented milk beverages were determined by the enzyme tests. It was found that the lactose content varied from 3.30 to 4.0 g/100g. All samples showed higher content glucose than fructose. The content of L-lactic acid in the samples ranged from 0.4 to 0.7 g/100g, while significantly lower level of D-lactic and acetic acid were determined in all samples of kombucha fermented milk (<0.06g/100g.[Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 46009

Bioconversion of lignocellulose-derived sugars to ethanol by engineered Saccharomyces cerevisiae.

Science.gov (United States)

Madhavan, Anjali; Srivastava, Aradhana; Kondo, Akihiko; Bisaria, Virendra S

2012-03-01

Lignocellulosic biomass from agricultural and agro-industrial residues represents one of the most important renewable resources that can be utilized for the biological production of ethanol. The yeast Saccharomyces cerevisiae is widely used for the commercial production of bioethanol from sucrose or starch-derived glucose. While glucose and other hexose sugars like galactose and mannose can be fermented to ethanol by S. cerevisiae, the major pentose sugars D-xylose and L-arabinose remain unutilized. Nevertheless, D-xylulose, the keto isomer of xylose, can be fermented slowly by the yeast and thus, the incorporation of functional routes for the conversion of xylose and arabinose to xylulose or xylulose-5-phosphate in Saccharomyces cerevisiae can help to improve the ethanol productivity and make the fermentation process more cost-effective. Other crucial bottlenecks in pentose fermentation include low activity of the pentose phosphate pathway enzymes and competitive inhibition of xylose and arabinose transport into the cell cytoplasm by glucose and other hexose sugars. Along with a brief introduction of the pretreatment of lignocellulose and detoxification of the hydrolysate, this review provides an updated overview of (a) the key steps involved in the uptake and metabolism of the hexose sugars: glucose, galactose, and mannose, together with the pentose sugars: xylose and arabinose, (b) various factors that play a major role in the efficient fermentation of pentose sugars along with hexose sugars, and (c) the approaches used to overcome the metabolic constraints in the production of bioethanol from lignocellulose-derived sugars by developing recombinant S. cerevisiae strains.

Rapid estimation of sugar release from winter wheat straw during bioethanol production using FTIR-photoacoustic spectroscopy

DEFF Research Database (Denmark)

Bekiaris, Georgios; Lindedam, Jane; Peltre, Clément

2015-01-01

Complexity and high cost are the main limitations for high-throughput screening methods for the estimation of the sugar release from plant materials during bioethanol production. In addition, it is important that we improve our understanding of the mechanisms by which different chemical components...... are affecting the degradability of plant material. In this study, Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was combined with advanced chemometrics to develop calibration models predicting the amount of sugars released after pretreatment and enzymatic hydrolysis of wheat straw during...

Bioaccessible peptides released by in vitro gastrointestinal digestion of fermented goat milks.

Science.gov (United States)

Moreno-Montoro, Miriam; Jauregi, Paula; Navarro-Alarcón, Miguel; Olalla-Herrera, Manuel; Giménez-Martínez, Rafael; Amigo, Lourdes; Miralles, Beatriz

2018-06-01

In this study, ultrafiltered goat milks fermented with the classical starter bacteria Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarus subsp. thermophilus or with the classical starter plus the Lactobacillus plantarum C4 probiotic strain were analyzed using ultra-high performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) and/or high performance liquid chromatography-ion trap (HPLC-IT-MS/MS). Partial overlapping of the identified sequences with regard to fermentation culture was observed. Evaluation of the cleavage specificity suggested a lower proteolytic activity of the probiotic strain. Some of the potentially identified peptides had been previously reported as angiotensin-converting enzyme (ACE) inhibitory, antioxidant, and antibacterial and might account for the in vitro activity previously reported for these fermented milks. Simulated digestion of the products was conducted in the presence of a dialysis membrane to retrieve the bioaccessible peptide fraction. Some sequences with reported physiological activity resisted digestion but were found in the non-dialyzable fraction. However, new forms released by digestion, such as the antioxidant α s1 -casein 144 YFYPQL 149 , the antihypertensive α s2 -casein 90 YQKFPQY 96 , and the antibacterial α s2 -casein 165 LKKISQ 170 , were found in the dialyzable fraction of both fermented milks. Moreover, in the fermented milk including the probiotic strain, the k-casein dipeptidyl peptidase IV inhibitor (DPP-IV) 51 INNQFLPYPY 60 as well as additional ACE inhibitory or antioxidant sequences could be identified. With the aim of anticipating further biological outcomes, quantitative structure activity relationship (QSAR) analysis was applied to the bioaccessible fragments and led to potential ACE inhibitory sequences being proposed. Graphical abstract Ultrafiltered goat milks were fermented with the classical starter bacteria (St) and with St plus the

Metabolic flux analysis during the exponential growth phase of Saccharomyces cerevisiae in wine fermentations.

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Manuel Quirós

Full Text Available As a consequence of the increase in global average temperature, grapes with the adequate phenolic and aromatic maturity tend to be overripe by the time of harvest, resulting in increased sugar concentrations and imbalanced C/N ratios in fermenting musts. This fact sets obvious additional hurdles in the challenge of obtaining wines with reduced alcohols levels, a new trend in consumer demands. It would therefore be interesting to understand Saccharomyces cerevisiae physiology during the fermentation of must with these altered characteristics. The present study aims to determine the distribution of metabolic fluxes during the yeast exponential growth phase, when both carbon and nitrogen sources are in excess, using continuous cultures. Two different sugar concentrations were studied under two different winemaking temperature conditions. Although consumption and production rates for key metabolites were severely affected by the different experimental conditions studied, the general distribution of fluxes in central carbon metabolism was basically conserved in all cases. It was also observed that temperature and sugar concentration exerted a higher effect on the pentose phosphate pathway and glycerol formation than on glycolysis and ethanol production. Additionally, nitrogen uptake, both quantitatively and qualitatively, was strongly influenced by environmental conditions. This work provides the most complete stoichiometric model used for Metabolic Flux Analysis of S. cerevisiae in wine fermentations employed so far, including the synthesis and release of relevant aroma compounds and could be used in the design of optimal nitrogen supplementation of wine fermentations.

Effects of in vitro fermentation of barley β-glucan and sugar beet pectin using human fecal inocula on cytokine expression by dendritic cells

NARCIS (Netherlands)

Rosch, Christiane; Taverne, Nico; Venema, Koen; Gruppen, Harry; Wells, Jerry M.; Schols, Henk A.

2017-01-01

Scope: This study simulates the fermentation process of barley β-glucan and sugar beet pectin in the human colon and monitors the degradation products formed. Additionally, immune effects of the degradation products were investigated. Methods and results: Immunostimulatory activity of

Mathematical modeling of the fermentation of acid-hydrolyzed pyrolytic sugars to ethanol by the engineered strain Escherichia coli ACCC 11177.

Science.gov (United States)

Chang, Dongdong; Yu, Zhisheng; Islam, Zia Ul; Zhang, Hongxun

2015-05-01

Pyrolysate from waste cotton was acid hydrolyzed and detoxified to yield pyrolytic sugars, which were fermented to ethanol by the strain Escherichia coli ACCC 11177. Mathematical models based on the fermentation data were also constructed. Pyrolysate containing an initial levoglucosan concentration of 146.34 g/L gave a glucose yield of 150 % after hydrolysis, suggesting that other compounds were hydrolyzed to glucose as well. Ethyl acetate-based extraction of bacterial growth inhibitors with an ethyl acetate/hydrolysate ratio of 1:0.5 enabled hydrolysate fermentation by E. coli ACCC 11177, without a standard absorption treatment. Batch processing in a fermenter exhibited a maximum ethanol yield and productivity of 0.41 g/g and 0.93 g/L·h(-1), respectively. The cell growth rate (r x ) was consistent with a logistic equation [Formula: see text], which was determined as a function of cell growth (X). Glucose consumption rate (r s ) and ethanol formation rate (r p ) were accurately validated by the equations [Formula: see text] and [Formula: see text], respectively. Together, our results suggest that combining mathematical models with fermenter fermentation processes can enable optimized ethanol production from cellulosic pyrolysate with E. coli. Similar approaches may facilitate the production of other commercially important organic substances.

Mechanism of Mg2+-Accompanied Product Release in Sugar Nucleotidyltransferases.

Science.gov (United States)

Vithani, Neha; Ankush Jagtap, Pravin Kumar; Verma, Sunil Kumar; Tripathi, Ravi; Awasthi, Shalini; Nair, Nisanth N; Prakash, Balaji

2018-03-06

The nucleotidyl transfer reaction, catalyzed by sugar nucleotidyltransferases (SNTs), is assisted by two active site Mg 2+ ions. While studying this reaction using X-ray crystallography, we captured snapshots of the pyrophosphate (product) as it exits along a pocket. Surprisingly, one of the active site Mg 2+ ions remains coordinated to the exiting pyrophosphate. This hints at the participation of Mg 2+ in the process of product release, besides its role in catalyzing nucleotidyl transfer. These observations are further supported by enhanced sampling molecular dynamics simulations. Free energy computations suggest that the product release is likely to be rate limiting in SNTs, and the origin of the high free energy barrier for product release could be traced back to the "slow" conformational change of an Arg residue at the exit end of the pocket. These results establish a dual role for Mg 2+ , and propose a general mechanism of product release during the nucleotidyl transfer by SNTs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enhanced bioprocessing of lignocellulose: Wood-rot fungal saccharification and fermentation of corn fiber to ethanol

Science.gov (United States)

Shrestha, Prachand

no improvement in ethanol yields. We showed that saccharification of lignocellulosic material with a wood-rot fungal process is quite feasible. Corn fiber from wet milling was best degraded to sugars using aerobic solid state fermentation with the soft-rot fungus T. reesei. However, it was shown that both the white-rot fungus P. chrysosporium and brown-rot fungus G. trabeum had the ability to produce additional consortia of hemi/cellulose degrading enzymes. It is likely that a consortium of enzymes from these fungi would be the best approach in saccharification of lignocellulose. In all cases, a subsequent anaerobic yeast process under submerged conditions is required to ferment the released sugars to ethanol. To our knowledge, this is the first time report on production of cellulolytic enzymes from wet-milled corn fiber using white- and brown-rot fungi for sequential fermentation of corn fiber hydrolyzate to ethanol. Keywords: lignocellulose, ethanol, biofuel, bioeconomy, biomass, renewable resources, corn fiber, pretreatment, solid-substrate fermentation, simultaneous saccharification and fermentation (SSF), white-rot fungus, brown-rot fungus, soft-rot fungus, fermentable sugars, enzyme activities, cellulytic enzymes Phanerochaete chrysosporium, Gloleophyllum trabeum, Trichoderma reesei, Saccharomyces cerevisiae.

Butanol production from wheat straw by simultaneous saccharification and fermentation using Clostridium beijerinckii: Part II-Fed-batch fermentation

International Nuclear Information System (INIS)

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

2008-01-01

In these studies, Clostridium beijerinckii P260 was used to produce butanol (acetone-butanol-ethanol, or ABE) from wheat straw (WS) hydrolysate in a fed-batch reactor. It has been demonstrated that simultaneous hydrolysis of WS to achieve 100% hydrolysis to simple sugars (to the extent achievable under present conditions) and fermentation to butanol is possible. In addition to WS, the reactor was fed with a sugar solution containing glucose, xylose, arabinose, galactose, and mannose. The culture utilized all of the above sugars. It was noticed that near the end of fermentation (286-533 h), the culture had difficulties utilizing xylose. As a result of supplemental sugar feed to the reactor, ABE productivity was improved by 16% as compared with previous studies. In our previous experiment on simultaneous saccharification of WS and fermentation to butanol, a productivity of 0.31 g L -1 h -1 was observed, while in the present studies a productivity of 0.36 g L -1 h -1 was observed. It should be noted that a productivity of 0.77 g L -1 h -1 was observed when the culture was highly active. The fed-batch fermentation was operated for 533 h. It should be noted that C. beijerinckii P260 can be used to produce butanol from WS in integrated fermentations

Thermophilic ethanol fermentation from lignocellulose hydrolysate by genetically engineered Moorella thermoacetica.

Science.gov (United States)

Rahayu, Farida; Kawai, Yuto; Iwasaki, Yuki; Yoshida, Koichiro; Kita, Akihisa; Tajima, Takahisa; Kato, Junichi; Murakami, Katsuji; Hoshino, Tamotsu; Nakashimada, Yutaka

2017-12-01

A transformant of Moorella thermoacetica was constructed for thermophilic ethanol production from lignocellulosic biomass by deleting two phosphotransacetylase genes, pdul1 and pdul2, and introducing the native aldehyde dehydrogenase gene (aldh) controlled by the promoter from glyceraldehyde-3-phosphate dehydrogenase. The transformant showed tolerance to 540mM and fermented sugars including fructose, glucose, galactose and xylose to mainly ethanol. In a mixed-sugar medium of glucose and xylose, all of the sugars were consumed to produce ethanol at the yield of 1.9mol/mol-sugar. The transformant successfully fermented sugars in hydrolysate prepared through the acid hydrolysis of lignocellulose to ethanol, suggesting that this transformant can be used to ferment the sugars in lignocellulosic biomass for ethanol production. Copyright © 2017 Elsevier Ltd. All rights reserved.

SILAGE CANE SUGAR ADDED WITH DRIED BREWER

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W. J. R. Castro

2015-02-01

Full Text Available The objective of this experiment was to evaluate the fermentative parameters and chemical composition of silage cane sugar added with residue dried brewery. The experimental design was completely randomized with four treatments and four replications: 100% cane sugar; 90% of cane sugar + 10% residue dried brewer; 80% of cane sugar + 20% residue dried brewer and 70% cane sugar + 30% dried brewer based on natural matter, composed silages. The sugar cane was chopped in a stationary machine with forage particle size of approximately 2 cm, and homogenized manually with the additives. For storage chopped fresh weight were used in experimental silos capacity of about 4 liters. The results showed that the contents of dry matter and crude protein showed positive linear (P0.05 with mean value of 3.81, while for ether extract and ash results were positive linear (P0.05 for N ammonia presented average value of 4.18. It is concluded that the addition of brewer dehydrated improves the fermentation process of silage cane sugar, in addition to improving their nutritional characteristics.

Ethanol fermentation by xylose-assimilating Saccharomyces cerevisiae using sugars in a rice straw liquid hydrolysate concentrated by nanofiltration.

Science.gov (United States)

Sasaki, Kengo; Sasaki, Daisuke; Sakihama, Yuri; Teramura, Hiroshi; Yamada, Ryosuke; Hasunuma, Tomohisa; Ogino, Chiaki; Kondo, Akihiko

2013-11-01

Concentrating sugars using membrane separation, followed by ethanol fermentation by recombinant xylose-assimilating Saccharomyces cerevisiae, is an attractive technology. Three nanofiltration membranes (NTR-729HF, NTR-7250, and ESNA3) were effective in concentrating glucose, fructose, and sucrose from dilute molasses solution and no permeation of sucrose. The separation factors of acetate, formate, furfural, and 5-hydroxymethyl furfural, which were produced by dilute acid pretreatment of rice straw, over glucose after passage through these three membranes were 3.37-11.22, 4.71-20.27, 4.32-16.45, and 4.05-16.84, respectively, at pH 5.0, an applied pressure of 1.5 or 2.0 MPa, and 25 °C. The separation factors of these fermentation inhibitors over xylose were infinite, as there was no permeation of xylose. Ethanol production from approximately two-times concentrated liquid hydrolysate using recombinant S. cerevisiae was double (5.34-6.44 g L(-1)) that compared with fermentation of liquid hydrolysate before membrane separation (2.75 g L(-1)). Copyright © 2013 Elsevier Ltd. All rights reserved.

Organosulphide profile and hydrogen sulphide-releasing activity of garlic fermented by Lactobacillus plantarum

NARCIS (Netherlands)

Tocmo, Restituto; Lai, Abigail Nianci; Wu, Yuchen; Liang, Dong; Fogliano, Vincenzo; Huang, Dejian

2017-01-01

Blanched and unblanched garlic were fermented using L. plantarum for investigation of organosulphide profiles, hydrogen sulphide-releasing activity, pH, titratable activity and microbial growth. Both raw and blanched garlic preparations allowed growth of L. plantarum with corresponding lowering of

Plant cell wall sugars: sweeteners for a bio-based economy.

Science.gov (United States)

Van de Wouwer, Dorien; Boerjan, Wout; Vanholme, Bartel

2018-02-12

Global warming and the consequent climate change is one of the major environmental challenges we are facing today. The driving force behind the rise in temperature is our fossil-based economy, which releases massive amounts of the greenhouse gas carbon dioxide into the atmosphere. In order to reduce greenhouse gas emission, we need to scale down our dependency on fossil resources, implying that we need other sources for energy and chemicals to feed our economy. Here, plants have an important role to play; by means of photosynthesis, plants capture solar energy to split water and fix carbon derived from atmospheric carbon dioxide. A significant fraction of the fixed carbon ends up as polysaccharides in the plant cell wall. Fermentable sugars derived from cell wall polysaccharides form an ideal carbon source for the production of bio-platform molecules. However, a major limiting factor in the use of plant biomass as feedstock for the bio-based economy is the complexity of the plant cell wall and its recalcitrance towards deconstruction. To facilitate the release of fermentable sugars during downstream biomass processing, the composition and structure of the cell wall can be engineered. Different strategies to reduce cell wall recalcitrance will be described in this review. The ultimate goal is to obtain a tailor-made biomass, derived from plants with a cell wall optimized for particular industrial or agricultural applications, without affecting plant growth and development. This article is protected by copyright. All rights reserved.

Study On Ethanol Production From Sugar Cane Molasses By Using Irradiated Saccharomyces Cerevisiae

International Nuclear Information System (INIS)

Botros, H.W.; Armed, A.S.; Farag, S.S.; Hassan, L.A.

2012-01-01

In commercial ethanol production procedures often use sugar cane molasses as a raw material due to- their abundance and low costs. The most employed microorganisms used for fermentation is Saccharomyces cerevisiae yeasts due to their ability to hydrolyze sucrose from sugar cane molasses into glucose and fructose; two easily assimilable hexoses. The aim of this study was to evaluate the effect of gamma irradiation on the activity of S. cerevisiae in the ethanol production yeast cells exposed to different doses of gamma rays (0.05, 0.1, 0.2, 0.4, 0.6, 0.8 and 1.0 KGy. The sugar cane substrate was optimized after maintaining deferent levels of sugar concentrations (12-21%), medium ph (4.0-5.5), incubation temperature (25-40 degree C) and rate of fermentation (24-168 h). The data showed that the rate of ethanol production reached its maximum by using the irradiated S. cerevisiae cells at 0.1 kGy dose at fermentation conditions as 15% sugar concentration, ph 4.5, incubation temperature 30 degree C, fermentation time 96 h at a fermentation medium volume 250 ml found in 500 ml Erlenmeyer flasks.

Study on Ethanol Production from Sugar Cane Molasses by Using Irradiated Saccharomyces cervisiae

International Nuclear Information System (INIS)

Botros, H.W.; Ahmed, A.S.; Farag, S.S.; Hassan, I.A.

2012-01-01

In commercial ethanol production procedures often use sugar cane molasses as a raw material due to their abundance and low costs. The most employed microorganisms used for fermentation is Saccharomyces cerevisiae yeasts due to its ability to hydrolyze sucrose from sugar cane molasses into glucose and fructose, two easily assimilable hexoses.The aim of this study was to evaluate the effect of gamma irradiation on the activity of S. cerevisiae in the ethanol production yeast cells exposed to different doses of gamma rays (0.05, 0.10, 0.2, 0.4, 0.6, 0.8 and 1.0 kGy. The sugar cane substrate was optimized after maintaining deferent levels of sugar concentrations (12-21%), medium ph (4.0-5.5), incubation temperature (25-40 degree C) and rate of fermentation (24-168) h. Data showed that rate of ethanol production was maximum by using the irradiated S. cerevisiae cells at 0.1 kGy. dose at fermentation conditions as 15% sugar concentration, initial ph 4.5, incubation temperature 30 degree C, fermentation time 96 h at a fermentation medium volume 250 ml found in 500 ml erlenmyer flasks.

Optimization of solid state fermentation of sugar cane by Aspergillus niger considering particles size effect

Energy Technology Data Exchange (ETDEWEB)

Echevarria, J.; Rodriguez, L.J.A.; Delgado, G. (Instituto Cubano de Investigaciones de los Derivados de la Cana de Azucar (ICIDCA), La Habana (Cuba)); Espinosa, M.E. (Centro Nacional de Investigaciones Cientificas, La Habana (Cuba))

1991-01-01

The protein enrichment of sugar cane by solid state fermentation employing Aspergillus niger was optimized in a packed bed column using a two Factor Central Composit Design {alpha} = 2, considering as independent factors the particle diameter corresponding to different times of grinding for a sample and the air flow rate. It was significative for the air flow rate (optimum 4.34 VKgM) and the particle diameter (optimum 0.136 cm). The average particle size distribution, shape factor, specific surface, volume-surface mean diameter, number of particles, real and apparent density and holloweness for the different times of grinding were determined, in order to characterize the samples. (orig.).

Wood hydrolyzate treatments for improved fermentation of wood sugars to 2,3-butanediol

Energy Technology Data Exchange (ETDEWEB)

Frazer, F.R.; McCaskey, T.A.

1989-01-01

Acid-hydrolyzed hardwood contains compounds inhibitory to micro-organisms that convert wood sugars to fermentation products such as fuels and chemicals. Several methods of treating acid-hydrolyzed hardwood (hydrolyzate) to reduce the levels of potential microbial inhibitors (acetate, furfural, sulfate, and phenolics) were evaluated. The methods evaluated were precipitation with calcium hydroxide, extraction with organic solvents, treatment with ion-exchange resins, adsorption resins, and activated charcoal. Treatment of the hydrolyzate with an anion exchange resin (Amberlite IRA-400) was the most effective method for removing potential inhibitors. Non-treatment hydrolyzate adjusted to pH 6 inhibited growth of a 2,3-butanediol-producing culture of Klebsiella pneumoniae. However, hydrolyzate treated with Amberlite IRA-400 was not inhibitory and resulted in yields of 2,3-butanediol that were greater than 90% of theoretical. (author).

Effects of Bacterial Inoculants and Absorbents on Fermentation Properties and Chemical Composition of Fresh Sugar Beet Pulp Silage Using Laboratory silos

Directory of Open Access Journals (Sweden)

Saeid Seidali Dolat-Abad

2016-04-01

Full Text Available Introduction Ensiling is one of the common preserving methods for forage or other organic materials. In this method, organic matters were preserved by proving an aerobic condition and then by reducing the pH with increasing acids production (mainly lactic acid. Some circumstances like enough soluble carbohydrates, low buffering capacity and appropriate dry matter concentration are needed in ensilages for an ideal silage production. Seepage production during ensiling is one of the most problems especially when high moisture materials (like fresh beet sugar pulp are ensiled. Silage seepage can pollute the environment and make loses in nutrients like soluble carbohydrates, protein, organic acids and etc. Moreover, lactic acid bacteria inoculants (Mainly consist of Lactobacillus plantarum have been widely used for improving fermentation pattern in ensilages. These external provided bacteria usually enhance lactic acid production in silage and then accelerate the falling of pH values in silages. Rapid decrease in pH can inhibit non-beneficial bacteria from activity which finally preserves nutrients from un-necessary fermentation or oxidation. The aim of this study was to investigate the interactive effects of lactic acid bacteria inoculants and some absorbents (straw and pith on chemical properties and fermentation profile of wet sugar beet pulp silage. Materials and Methods In the first experiment, fresh wet sugar beet pulp was treated with 5% straw or 5% pith in order to investigate the effects of these absorbents on chemical composition, fermentation characteristics and effluent production during ensiling period. In the second experiment, fresh wet sugar beet pulp was treated with a commercial lactic acid bacteria inoculants (Ecosyle and/or 5% pith in order to investing the main and interaction effects of the bacterial bacteria inoculants and the best absorbents from the experiment 1. In both experiments, triplicate samples were prepared for each

Production of Fermented Kale Juices with Lactobacillus Strains and Nutritional Composition

Science.gov (United States)

Kim, Seong Yeong

2017-01-01

Fermented kale juices using four types of lactobacilli were produced in the present study. After 48 h of fermentation time, viable cell counts of all ferments reached an above 109 CFU/mL. The viability of the ferments after cold storage in the refrigerator for 4 weeks showed 108 CFU/mL in all ferments. Among four types of fermented kale juices, the ferment of Lactobacillus acidophilus IFO 3025 indicated a good nutritional composition, including neutral sugar (1,909.76 μg/mL), reducing sugar (564.00 μg/mL, Pkale juices may be suggested as a healthy fermented beverage with essential nutrients. However, the acceptability of the fermented kale juice to the Korean taste should be further investigated with a trained taste panel to determine whether inoculated fermentation could be an option for the consumers. PMID:29043222

Sucrose fermentation by Saccharomyces cerevisiae lacking hexose transport.

Science.gov (United States)

Batista, Anderson S; Miletti, Luiz C; Stambuk, Boris U

2004-01-01

Sucrose is the major carbon source used by Saccharomyces cerevisiae during production of baker's yeast, fuel ethanol and several distilled beverages. It is generally accepted that sucrose fermentation proceeds through extracellular hydrolysis of the sugar, mediated by the periplasmic invertase, producing glucose and fructose that are transported into the cells and metabolized. In the present work we analyzed the contribution to sucrose fermentation of a poorly characterized pathway of sucrose utilization by S. cerevisiae cells, the active transport of the sugar through the plasma membrane and its intracellular hydrolysis. A yeast strain that lacks the major hexose transporters (hxt1-hxt7 and gal2) is incapable of growing on or fermenting glucose or fructose. Our results show that this hxt-null strain is still able to ferment sucrose due to direct uptake of the sugar into the cells. Deletion of the AGT1 gene, which encodes a high-affinity sucrose-H(+) symporter, rendered cells incapable of sucrose fermentation. Since sucrose is not an inducer of the permease, expression of the AGT1 must be constitutive in order to allow growth of the hxt-null strain on sucrose. The molecular characterization of active sucrose transport and fermentation by S. cerevisiae cells opens new opportunities to optimize yeasts for sugarcane-based industrial processes.

Productivity and fermentability of Jerusalem artichoke according to harvesting date

Energy Technology Data Exchange (ETDEWEB)

Chabbert, N.; Arnoux, M.; Braun, Ph.; Galzy, P.; Guiraud, J.P.

1983-01-01

The amount of alcohol obtained per hectare of Jerusalem artichoke culture depends on the yield of tubers, the sugar content of the tubers and the fermentability of these sugars. Under Mediterranean climate conditions, the cultivar 'Violet commun' attained its maximum tuber production by 15 November, when the stems and leaves dried up, and then remained constant through the winter. The sugar content of the tubers varied little during this period. However, the sugar composition did vary with time: the polyfructosans were depolymerized. The fermentability of sugars without prior chemical hydrolysis was quite good with Kluyveromyces marxianus which showed high inulinase activity in contrast to Saccharomyces cerevisiae.

Productivity and fermentability of Jerusalem artichoke according to harvesting date

Energy Technology Data Exchange (ETDEWEB)

Chabbert, N.; Braun, P.; Guiraud, J.P.; Arnoux, M.; Galzy, P.

1983-01-01

The amount of alcohol obtained per hectare of Jerusalem artichoke culture depends on the yield of tubers, the sugar content of the tubers and the fermentability of these sugars. Under Mediterranean climate conditions, the cultivar Violet commun attained its maximum tuber production by 15 November, when the stems and leaves dried up, and then remained constant through the winter. The sugar content of the tubers varied little during this period. However, the sugar composition did vary with time: the polyfructosans were depolymerized. The fermentability of sugars without prior chemical hydrolysis was quite good with Kluyveromyces marxianus which showed high inulinase activity in contrast to Saccaromyces cerevisiae. 5 figures, 1 table.

Productivity and fermentability of Jerusalem artichoke according to harvesting date

Energy Technology Data Exchange (ETDEWEB)

Chabbert, M.; Braunt, Ph.; Guiraud, J.P.; Arnoux, M.; Galzy, P.

1983-01-01

The amount of alcohol obtained per hectare of Jerusalem artichoke culture depends on the yield of tubers, the sugar content of the tubers and the fermentability of these sugars. Under Mediterranean climate conditions, the cultivar 'Violet commun' attained its maximum tuber production by 15 November, when the stems and leaves dried up, and then remained constant through the winter. The sugar content of the tubers varied little during this period. However, the sugar composition did vary with time: the polyfructosans were depolymerized. The fermentability of sugars without prior chemical hydrolysis was quite good with Kluyveromyces marxianus which showed high inulinase activity in contrast to Saccharomyces cerevisiae. (Refs. 13).

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 prescribed...

Utilization of date carbohydrate as substrate in microbial fermentation

Energy Technology Data Exchange (ETDEWEB)

Kamel, B.S.

1979-06-01

In a study of 3 yeasts, ogi yeast showed the highest conversion rate and cell production in both shake flasks and fermenters using a juice with 4% soluble solids extracted from dates with an average of 65% sugar. Corn steep liquor increased the growth rate, 4% having the greatest effect. The highest cell production of the ogi yeast was at 37 degrees (4.92 g/L) and 50% of the sugar was converted. An associative fermentation using a mixed culture of Candida utilis and Saccharomyces cerevisiae gave better results than fermentations using each organism alone. The fermentation using S.rouxxi NRRL Y-2547 was also studied.

Single zymomonas mobilis strain for xylose and arabinose fermentation

Science.gov (United States)

Zhang, Min; Chou, Yat-Chen; Picataggio, Stephen K.; Finkelstein, Mark

1998-01-01

This invention relates to single microorganisms which normally do not ferment pentose sugars which are genetically altered to ferment the pentose sugars, xylose and arabinose, to produce ethanol, and a fermentation process utilizing the same. Examples include Zymomonas mobilis which has been transformed with a combination of E. coli genes for xylose isomerase, xylulokinase, L-arabinose isomerase, L-ribulokinase, L-ribulose 5-phosphate 4-epimerase, transaldolase and transketolase. Expression of added genes are under the control of Z. mobilis promoters. These newly created microorganisms are useful for fermenting glucose, xylose and arabinose, produced by hydrolysis of hemicellulose and cellulose or starch, to produce ethanol.

The Leachate Release and Microstructure of the Sewage Sludge under the Anaerobic Fermentation

Directory of Open Access Journals (Sweden)

Yiqie Dong

2015-01-01

Full Text Available Pollutant release, pore structure, and thermal effect of sewage sludge during anaerobic fermentation were investigated. Results showed that the pH value firstly declined and then increased during anaerobic fermentation. The BOD5 and organics of sewage sludge declined, and the BOD5 of samples which was originally neutral declined as much as 53.6%. The micropore of samples was relatively developed. The biggest adsorption amount was 69.2 cm3/g. The average pore size was enlarged about 16.0–19.8% under anaerobic fermentation. There existed endothermic valley during heating procedure of 0–200∘C because of the dehydration, and the mass loss was 60.9–72.5%. The endothermic valley of the sample fluctuated at the 14th day in the anaerobic fermentation. During the heating procedure of 200–600∘C, there existed exothermal peaks because of the oxidation and burning of the organics. The curve of sample which was originally neutral had comparatively large endothermic valley and exothermal peak.

Alcoholic fermentation of starchy and sugary materials

Energy Technology Data Exchange (ETDEWEB)

Gulyaev, S P

1958-06-25

To promote complete fermentation of the sugar and to reduce the formation of glycerol and other by-products, the ester-aldehyde fraction is introduced to the fermentation mixture at the beginning of the process.

Forage and sugar in dairy calves' starter diet and their interaction on performance, weaning age and rumen fermentation.

Science.gov (United States)

Beiranvand, H; Ghorbani, G R; Khorvash, M; Kazemi-Bonchenari, M

2014-06-01

The effects of sugar and forage inclusion in calves' starter and their interaction on animal performance and rumen fermentation parameters were investigated. Twenty-eight neonatal Holstein male calves 3 days of age with average body weights of 42 ± 4 kg were allocated to four different treatments. All calves were fed a similar basal diet consisting of milk and concentrate. The experimental treatments were: (i) basal diet with no supplementation (Control, hereafter designated by C), (ii) basal diet plus 5% granular sugar cane (Sugar, designated by S), (iii) basal diet plus 5% forage (Forage, designated by F) and (iv) basal diet plus 5% forage with 5% granular sugar cane (F × S). Supplement ingredients were used on a dry matter (DM) basis. Rumen fluid parameters were measured twice on days 35 and 70 of the study period. The calves were weaned when they could consume 1 kg of starter for three consecutive days. The results show that starter intake was not affected by treatment; however, the lowest ADG was observed with calves in the sugar treatment. Weaning age was affected by treatments, and forage showed to reduce milk consumption period down to its shortest. Forage-sugar interaction was found to have no effects on animal performance. The structural body indices as well as the health status of the calves were similar in different treatments. Rumen pH did not differ among the treatment groups. Among the rumen parameters, total VFA concentration and molar proportions of butyrate and propionate did not exhibit any significant differences among the treatments. However, ruminal acetate concentration decreased in calves that fed sugar cane during the early weeks of the study period. Comparison of forage and sugar included in the starter diets revealed that forage reduced weaning age, while sugar cane had a negative effect on calves' performance. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

Changes in physical and chemical characteristics of fermented cocoa(Theobroma cacaobeans with manual and semi-mechanized transfer, between fermentation boxes

Directory of Open Access Journals (Sweden)

Pedro. P. Peláez

2016-01-01

Full Text Available The aim of this study was to evaluate variation in the physical and chemical properties of fermented cocoa beans with cocoa beans transfer between wooden fermentation boxes manually (M and semi - mechanized (SM way. Mass temperature, moisture, pH, and total acidity of the cotyledon and pulp; the total polyphenol, anthocyanin, reducing sugar, theobromine, and caffeine content in fresh, fermented, and dried beans; and percentage of fermented beans and time required to move beans during fermentation were determined. The cocoa used grew in the Pachiza district of the San Martin region of Peru. Cocoa sampling w as each 0, 48, 72, 96, 120, 144, and 168 h of fermentation. The cocoa mass temperature was highest with both removal systems after 96 h of fermentation. M cotyledon and pulp samples had the highest moisture content and titratable acidity, while cotyledon a nd pulp pH with both systems were statistically equal. In contrast, fermented beans had a higher polyphenol, anthocyanin, reducing sugar, theobromine, and caffeine content with SM. SM produced the greatest amount of fermentation (91.67% and required the s hortest amount of time to move beans (78.56 min. In conclusion, the system of fermentation of cocoa beans with SM was faster and produced fermented grains with high chemical quality.

Simultaneous Saccharification and Fermentation and Partial Saccharification and Co-Fermentation of Lignocellulosic Biomass for Ethanol Production

Science.gov (United States)

Doran-Peterson, Joy; Jangid, Amruta; Brandon, Sarah K.; Decrescenzo-Henriksen, Emily; Dien, Bruce; Ingram, Lonnie O.

Ethanol production by fermentation of lignocellulosic biomass-derived sugars involves a fairly ancient art and an ever-evolving science. Production of ethanol from lignocellulosic biomass is not avant-garde, and wood ethanol plants have been in existence since at least 1915. Most current ethanol production relies on starch- and sugar-based crops as the substrate; however, limitations of these materials and competing value for human and animal feeds is renewing interest in lignocellulose conversion. Herein, we describe methods for both simultaneous saccharification and fermentation (SSF) and a similar but separate process for partial saccharification and cofermentation (PSCF) of lignocellulosic biomass for ethanol production using yeasts or pentose-fermenting engineered bacteria. These methods are applicable for small-scale preliminary evaluations of ethanol production from a variety of biomass sources.

Changes in physical and chemical characteristics of fermented cocoa (Theobroma cacao beans with manual and semi-mechanized transfer, between fermentation boxes

Directory of Open Access Journals (Sweden)

Pedro. P. Peláez

2016-06-01

Full Text Available The aim of this study was to evaluate variation in the physical and chemical properties of fermented cocoa beans with cocoa beans transfer between wooden fermentation boxes manually (M and semi-mechanized (SM way. Mass temperature, moisture, pH, and total acidity of the cotyledon and pulp; the total polyphenol, anthocyanin, reducing sugar, theobromine, and caffeine content in fresh, fermented, and dried beans; and percentage of fermented beans and time required to move beans during fermentation were determined. The cocoa used grew in the Pachiza district of the San Martin region of Peru. Cocoa sampling was each 0, 48, 72, 96, 120, 144, and 168 h of fermentation. The cocoa mass temperature was highest with both removal systems after 96 h of fermentation. M cotyledon and pulp samples had the highest moisture content and titratable acidity, while cotyledon and pulp pH with both systems were statistically equal. In contrast, fermented beans had a higher polyphenol, anthocyanin, reducing sugar, theobromine, and caffeine content with SM. SM produced the greatest amount of fermentation (91.67% and required the shortest amount of time to move beans (78.56 min. In conclusion, the system of fermentation of cocoa beans with SM was faster and produced fermented grains with high chemical quality.

A dynamic flux balance model and bottleneck identification of glucose, xylose, xylulose co-fermentation in Saccharomyces cerevisiae

Science.gov (United States)

Economically viable production of lignocellulosic ethanol requires efficient conversion of feedstock sugars to ethanol. Saccharomyces cerevisiae cannot ferment xylose, the main five-carbon sugars in biomass, but can ferment xylulose, an enzymatically derived isomer. Xylulose fermentation is slow rel...

Butanol by fermentation

Energy Technology Data Exchange (ETDEWEB)

Hongo, M

1960-07-19

BuOH is produced by inoculating a carbohydrate mash with Clostridium saccharoperbutylacetonicum (ATCC 13564), fermenting the inoculated mash, and recovering the BuOH by fractional distillation. Thus, a medium containing sugar 4, (NH/sub 4/)/sub 2/SO/sub 4/ 0.2, Ca superphosphate 0.1, and CoCO/sub 3/ 0.3% is inoculated with a C. saccharoperbutylacetonicum culture and cultivated at 30/sup 0/ until the acidity begins to decrease. Then the culture is transferred to a second medium of similar composition. This transfer is repeated a third time, and then the culture is transferred to the main mash (same composition) and fermented for 60 hours at 30/sup 0/. The yield of BuOH is 11.5 g/1 or 25.5% of the sugar supplied.

Fermentation of sugar beet waste by ¤Aspergillus niger¤ facilitates growth and P uptake of external mycelium of mixed populations of arbuscular mycorrhizal fungi

DEFF Research Database (Denmark)

Medina, A.; Jakobsen, Iver; Vassilev, N.

2007-01-01

Sugar beet waste has potential value as a soil amendment and this work studied whether fermentation of the waste by Aspergillus niger would influence the growth and P uptake of arbuscular mycorrhizal (AM) fungi. Plants were grown in compartmentalised growth units, each with a root compartment (RC...

The Use of Titrimetric, Nelson Somogyi and Hplc Methods for the Analysis of Cashew Apple Juice Fermentation Broths

OpenAIRE

Kantasubrata, Julia; T. Karossi, A; S. Pramudi, A

1993-01-01

In cashew apple juice fermentation to produce wine and vinegar, analysis of organic acids and sugars in fermentation broths is very important, due to the fact that optimum conditions of fermentation could only be established from results obtained on monitoring the concentrations of those components during the fermentation process. Analysis of organic acids by tiirimetric method and analysis of sugars by Nelson-Somogyi method only give a total amount of acids and sugars. HPLC is one of the pro...

Two Novel Strains of Torulaspora delbrueckii Isolated from the Honey Bee Microbiome and Their Use in Honey Fermentation

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Joseph P. Barry

2018-03-01

Full Text Available Yeasts are ubiquitous microbes found in virtually all environments. Many yeast species can ferment sugar into ethanol and CO2, and humans have taken advantage of these characteristics to produce fermented beverages for thousands of years. As a naturally abundant source of fermentable sugar, honey has had a central role in such fermentations since Neolithic times. However, as beverage fermentation has become industrialized, the processes have been streamlined, including the narrow and almost exclusive usage of yeasts in the genus Saccharomyces for fermentation. We set out to identify wild honey- or honey-bee-related yeasts that can be used in honey fermentation. Here, we isolated two strains of Torulaspora delbrueckii from the gut of a locally collected honey bee. Both strains were able to ferment honey sugar into mead but failed to metabolize more than a modest amount of wort sugar in trial beer fermentations. Further, the meads fermented by the T. delbrueckii strains displayed better sensory characteristics than mead fermented by a champagne yeast. The combination of T. delbrueckii and champagne yeast strains was also able to rapidly ferment honey at an industrial scale. Thus, wild yeasts represent a largely untapped reservoir for the introduction of desirable sensory characteristics in fermented beverages such as mead.

Fermentation strategy for second generation ethanol production from sugarcane bagasse hydrolyzate by Spathaspora passalidarum and Scheffersomyces stipitis.

Science.gov (United States)

Nakanishi, Simone C; Soares, Lauren B; Biazi, Luiz Eduardo; Nascimento, Viviane M; Costa, Aline C; Rocha, George Jackson M; Ienczak, Jaciane L

2017-10-01

Alcoholic fermentation of released sugars in pretreatment and enzymatic hydrolysis of biomass is a central feature for second generation ethanol (E2G) production. Saccharomyces cerevisiae used industrially in the production of first generation ethanol (E1G) convert sucrose, fructose, and glucose into ethanol. However, these yeasts have no ability to ferment pentose (xylose). Therefore, the present work has focused on E2G production by Scheffersomyces stipitis and Spathaspora passalidarum. The fermentation strategy with high pitch, cell recycle, fed-batch mode, and temperature decrease for each batch were performed in a hydrolyzate obtained from a pretreatment at 130°C with NaOH solution (1.5% w/v) added with 0.15% (w/w) of anthraquinone (AQ) and followed by enzymatic hydrolysis. The process strategy has increased volumetric productivity from 0.35 to 0.38 g · L -1  · h -1 (first to third batch) for S. stipitis and from 0.38 to 0.81 g · L -1  · h -1 for S. passalidarum (first to fourth batch). Mass balance for the process proposed in this work showed the production of 177.33 kg ethanol/ton of sugar cane bagasse for S. passalidarum compared to 124.13 kg ethanol/ton of sugar cane bagasse for S. stipitis fermentation. The strategy proposed in this work can be considered as a promising strategy in the production of second generation ethanol. Biotechnol. Bioeng. 2017;114: 2211-2221. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Alcoholic fermentation

Energy Technology Data Exchange (ETDEWEB)

Colin, P

1961-01-04

The addition of C/sub 6-10/ alcohols to the fermenting sugar solutions, increased the yield of alcohol by 1.5 to 5%. The best additives were (additive, % additive in sugar solution, % increased in yield of alcohol): hexanol, 0.03, 2.5; heptanol, 0.05, 3; nonanol, 0.01, 3; 2-ethylbutanol, 0.05, 4; 2-ethylhexanol, 0.05, 5; a mixture of C/sub 7-9/ alcohols from the Oxo synthesis, 0.05, 4.5, and a mixture of C/sub 10/ alcohols 0.05, 3.

Alcohol from sugar beets

Energy Technology Data Exchange (ETDEWEB)

Malchenko, A L; Verzhbitskaya, V A

1962-01-01

The factor which determines the economy in the EtOH industry which uses sugar beets as raw materials is the rapid and complete recovery of the sugar contained in the beets for fermentation purposes. It is best to extract the beets at 70 to 75/sup 0/. Thorough shredding of the beets then need no longer form part of the operation, and the protein compounds, which give rise to fuel oils, are extracted in small amounts only.

Enzymatic hydrolysis of various pretreated lignocellulosic substrates and the fermentation of the liberated sugars to ethanol and butanediol

Energy Technology Data Exchange (ETDEWEB)

Saddler, J.N.; Mes-Hartree, M.; Yu, E.K.C.; Brownell, H.H.

1983-01-01

Aspen wood and wheat straw were pretreated by exposure to steam at elevated temperatures. Chemical analysis of the substrates revealed that steam explosion differentially decomposed the pentosan component while leaving the glucan portion relatively unchanged. The pretreated residues could be used as substrates for growth of Trichoderma reesei C30 and T. harzianum E58. The cellulase activities detected were in some cases three times as high as those found when Solka Floc was used as the substrate. Culture filtrates of T. harzianum E58 could efficiently hydrolyze the hemicellulose-rich water-soluble fractions. This material was fermented by Klebsiella pneumoniae with 0.4-0.5 g of 2,3-butanediol produced per gram of sugar utilized. Once the steam-exploded residues had been water and alkali extracted, the enzymatically hydrolyzed substrates were readily fermented by Saccharomyces cerevisiae or Zymononas mobilis with values as high as 2% (w/v) ethanol obtained from 5% steam-exploded wood fractions. 30 references, 2 figures, 8 tables.

Fermentation of sugar solutions to butanol, acetone, and ethanol

Energy Technology Data Exchange (ETDEWEB)

Karsch, W; Schoeder, K

1956-04-05

A three-stage (two preliminary and one main stage) fermentation process with a high yield of fermentation products (BuOH, Me/sub 2/CO, and EtOH) due to the addition of Ca(OAc)/sub 2/ or AcOH is described. According to this the acetate is added in the first and second stages only; this saves a large amount of acetate. The acetate level of the solution can also be regulated by mixing fermentable solutions of different AcOH content.

Ethanol production in fermentation of mixed sugars containing xylose

Science.gov (United States)

Viitanen, Paul V [West Chester, PA; Mc Cutchen, Carol M [Wilmington, DE; Li,; Xu, [Newark, DE; Emptage, Mark [Wilmington, DE; Caimi, Perry G [Kennett Square, PA; Zhang, Min [Lakewood, CO; Chou, Yat-Chen [Lakewood, CO; Franden, Mary Ann [Centennial, CO

2009-12-08

Xylose-utilizing Z. mobilis strains were found to have improved ethanol production when grown in medium containing mixed sugars including xylose if sorbitol or mannitol was included in the medium. The effect was seen in concentrations of mixed sugars where no growth lag period occurs, as well as in higher sugars concentrations.

Complete oxidative conversion of lignocellulose derived non-glucose sugars to sugar acids by Gluconobacter oxydans.

Science.gov (United States)

Yao, Ruimiao; Hou, Weiliang; Bao, Jie

2017-11-01

Non-glucose sugars derived from lignocellulose cover approximately 40% of the total carbohydrates of lignocellulose biomass. The conversion of the non-glucose sugars to the target products is an important task of lignocellulose biorefining research. Here we report a fast and complete conversion of the total non-glucose sugars from corn stover into the corresponding sugar acids by whole cell catalysis and aerobic fermentation of Gluconobacter oxydans. The conversions include xylose to xylonate, arabinose to arabonate, mannose to mannonate, and galactose to galactonate, as well as with glucose into gluconate. These cellulosic non-glucose sugar acids showed the excellent cement retard setting property. The mixed cellulosic sugar acids could be used as cement retard additives without separation. The conversion of the non-glucose sugars not only makes full use of lignocellulose derived sugars, but also effectively reduces the wastewater treatment burden by removal of residual sugars. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of polymer coated slow-release urea on ruminal fermentation and nutrient total tract digestion of beef steers

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Rodrigo Gardinal

2016-02-01

Full Text Available ABSTRACT The objective of this study was to evaluate the effects of polymer coated slow-release urea (SRU in high-forage diets of beef steers on nutrient intake and digestibility, ruminal fermentation, microbial protein synthesis, and energy balance. Eight 24-mo-old rumen-fistulated castrated Nellore steers (average body weight = 418.0±40.0 kg were used in a replicated 4 × 4 Latin square design. Animals were randomly distributed to receive one of the following diets: no urea inclusion; 1.0% inclusion of feed grade urea in the diet (dry matter [DM] basis; 1.0% inclusion of slow-release urea 1 in the diet (DM basis; and 1.0% inclusion of slow-release urea 2 in the diet (DM basis. Slow-release urea 2 had a similar composition to that of slow-release urea 1 and differed in that it contained 2.95% sulfur. A high-forage diet was provided (75% of total DM and corn silage was used as the forage source. Diets with urea had increased crude protein (CP intake, and CP and total digestible nutrients total tract digestion. Urea sources increased ruminal concentrations of ammonia nitrogen and acetate, and decreased butyrate concentrations. The polymer coated urea did not alter ruminal fermentation when compared with feed grade urea. Diets did not affect the energy balance of steers. Feed grade urea presented greater microbial protein synthesis than polymer coated slow-release urea. The partial replacement of soybean meal by 1% slow-release urea in a diet with 75% forage does not improve ruminal fermentation and microbial protein synthesis, and shows similar results as feeding feed grade urea to beef steers.

Fed batch enzymatic saccharification of food waste improves the sugar concentration in the hydrolysates and eventually the ethanol fermentation by Saccharomyces cerevisiae H058

Directory of Open Access Journals (Sweden)

Shoubao Yan

2012-04-01

Full Text Available The enzymatic hydrolysis of food waste by commercially available enzymes and the subsequent ethanol fermentation of the hydrolysates by Saccharomyces cerecisiae H058 were studied in this work. The optimum batch enzymatic conditions were found to be saccharification pH of 4.5, temperature of 55!, glucoamylase concentration of 120 u/g, α-amylase concentration of 10 u/g, solid-liquid ratio of 1: 0.75 (w/w. Fed batch hydrolysis process was started with a solid-liquid ratio of 1: 1 (w/w, with solid food waste added at time lapse of 2 h to get a final solid-liquid ratio of 1: 0.5 (w/w. After 4 h of reaction, the reducing sugar concentration reached 194.43 g/L with a enzymatic digestibility of 93.12%. Further fermentation of the batch and fed batch enzymatic hydrolysates, which contained reducing sugar concentration of 131.41 and 194.43 g/L respectively, was performed using Saccharomyces cerevisiae H058, 62.93 and 90.72 g/L ethanol was obtained within 48 h.

Graded replacement of maize grain with molassed sugar beet pulp modulated ruminal microbial community and fermentation profile in vitro.

Science.gov (United States)

Münnich, Matthias; Khol-Parisini, Annabella; Klevenhusen, Fenja; Metzler-Zebeli, Barbara U; Zebeli, Qendrim

2018-02-01

Molassed sugar beet pulp (Bp) is a viable alternative to grains in cattle nutrition for reducing human edible energy input. Yet little is known about the effects of high inclusion rates of Bp on rumen microbiota. This study used an in vitro approach and the quantitative polymerase chain reaction technique to establish the effects of a graded replacement of maize grain (MG) by Bp on the ruminal microbial community, fermentation profile and nutrient degradation. Six different amounts of Bp (0-400 g kg -1 ), which replaced MG in the diet, were tested using the in vitro semi-continuous rumen simulation technique. The increased inclusion of Bp resulted in greater dietary content and degradation of neutral detergent fibre (P fermentation. However, high replacement rates of Bp resulted in lowered utilization of ammonia and higher ruminal methane production. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Simulation and optimization of continuous extractive fermentation with recycle system

Science.gov (United States)

Widjaja, Tri; Altway, Ali; Rofiqah, Umi; Airlangga, Bramantyo

2017-05-01

Extractive fermentation is continuous fermentation method which is believed to be able to substitute conventional fermentation method (batch). The recovery system and ethanol refinery will be easier. Continuous process of fermentation will make the productivity increase although the unconverted sugar in continuous fermentation is still in high concentration. In order to make this process more efficient, the recycle process was used. Increasing recycle flow will enhance the probability of sugar to be re-fermented. However, this will make ethanol enter fermentation column. As a result, the accumulated ethanol will inhibit the growth of microorganism. This research aims to find optimum conditions of solvent to broth ratio (S:B) and recycle flow to fresh feed ratio in order to produce the best yield and productivity. This study employed optimization by Hooke Jeeves method using Matlab 7.8 software. The result indicated that optimum condition occured in S: B=2.615 and R: F=1.495 with yield = 50.2439 %.

Increased seedling establishment via enemy release at the upper elevational range limit of sugar maple.

Science.gov (United States)

Urli, Morgane; Brown, Carissa D; Narváez Perez, Rosela; Chagnon, Pierre-Luc; Vellend, Mark

2016-11-01

The enemy release hypothesis is frequently invoked to explain invasion by nonnative species, but studies focusing on the influence of enemies on natural plant range expansion due to climate change remain scarce. We combined multiple approaches to study the influence of plant-enemy interactions on the upper elevational range limit of sugar maple (Acer saccharum) in southeastern Québec, Canada, where a previous study had demonstrated intense seed predation just beyond the range limit. Consistent with the hypothesis of release from natural enemies at the range limit, data from both natural patterns of regeneration and from seed and seedling transplant experiments showed higher seedling densities at the range edge than in the core of the species' distribution. A growth chamber experiment manipulating soil origin and temperature indicated that this so-called "happy edge" was not likely caused by temperature (i.e., the possibility that climate warming has made high elevation temperatures optimal for sugar maple) or by abiotic soil factors that vary along the elevational gradient. Finally, an insect-herbivore-exclusion experiment showed that insect herbivory was a major cause of seedling mortality in the core of sugar maple's distribution, whereas seedlings transplanted at or beyond the range edge experienced minimal herbivory (i.e., enemy release). Insect herbivory did not completely explain the high levels of seedling mortality in the core of the species' distribution, suggesting that seedlings at or beyond the range edge may also experience release from pathogens. In sum, while some effects of enemies are magnified beyond range edges (e.g., seed predation), others are dampened at and beyond the range edge (e.g., insect herbivory), such that understanding the net outcome of different biotic interactions within, at and beyond the edge of distribution is critical to predicting species' responses to global change. © 2016 by the Ecological Society of America.

Fermentation process for alcoholic beverage production from mahua ...

African Journals Online (AJOL)

Ezedom Theresa

2013-09-25

Sep 25, 2013 ... Key words: Madhuca indica, ethanol, reducing sugar, fermentation. ... The mahua flowers obtained were cleaned and dried in hot air oven at 60°C ... methanol in the fermented sample was determined with the help of.

Combined enzyme mediated fermentation of cellulose and xylose to ethanol by Schizosaccharomyces pombe, cellulase, [beta]-glucosidase, and xylose isomerase

Science.gov (United States)

Lastick, S.M.; Mohagheghi, A.; Tucker, M.P.; Grohmann, K.

1994-12-13

A process for producing ethanol from mixed sugar streams from pretreated biomass comprising xylose and cellulose using enzymes to convert these substrates to fermentable sugars; selecting and isolating a yeast Schizosaccharomyces pombe ATCC No. 2476, having the ability to ferment these sugars as they are being formed to produce ethanol; loading the substrates with the fermentation mix composed of yeast, enzymes and substrates; fermenting the loaded substrates and enzymes under anaerobic conditions at a pH range of between about 5.0 to about 6.0 and at a temperature range of between about 35 C to about 40 C until the fermentation is completed, the xylose being isomerized to xylulose, the cellulose being converted to glucose, and these sugars being concurrently converted to ethanol by yeast through means of the anaerobic fermentation; and recovering the ethanol. 2 figures.

Enhancing ethanol yields through d-xylose and l-arabinose co-fermentation after construction of a novel high efficient l-arabinose-fermenting Saccharomyces cerevisiae strain.

Science.gov (United States)

Caballero, Antonio; Ramos, Juan Luis

2017-04-01

Lignocellulose contains two pentose sugars, l-arabinose and d-xylose, neither of which is naturally fermented by first generation (1G) ethanol-producing Saccharomyces cerevisiae yeast. Since these sugars are inaccessible to 1G yeast, a significant percentage of the total carbon in bioethanol production from plant residues, which are used in second generation (2G) ethanol production, remains unused. Recombinant Saccharomyces cerevisiae strains capable of fermenting d-xylose are available on the market; however, there are few examples of l-arabinose-fermenting yeasts, and commercially, there are no strains capable of fermenting both d-xylose and l-arabinose because of metabolic incompatibilities when both metabolic pathways are expressed in the same cell. To attempt to solve this problem we have tested d-xylose and l-arabinose co-fermentation. To find efficient alternative l-arabinose utilization pathways to the few existing ones, we have used stringent methodology to screen for new genes (metabolic and transporter functions) to facilitate l-arabinose fermentation in recombinant yeast. We demonstrate the feasibility of this approach in a successfully constructed yeast strain capable of using l-arabinose as the sole carbon source and capable of fully transforming it to ethanol, reaching the maximum theoretical fermentation yield (0.43 g g-1). We demonstrate that efficient co-fermentation of d-xylose and l-arabinose is feasible using two different co-cultured strains, and observed no fermentation delays, yield drops or accumulation of undesired byproducts. In this study we have identified a technically efficient strategy to enhance ethanol yields by 10 % in 2G plants in a process based on C5 sugar co-fermentation.

Countercurrent extraction of soluble sugars from almond hulls and assessment of the bioenergy potential.

Science.gov (United States)

Holtman, Kevin M; Offeman, Richard D; Franqui-Villanueva, Diana; Bayati, Andre K; Orts, William J

2015-03-11

Almond hulls contain considerable proportions (37% by dry weight) of water-soluble, fermentable sugars (sucrose, glucose, and fructose), which can be extracted for industrial purposes. The maximum optimal solids loading was determined to be 20% for sugar extraction, and the addition of 0.5% (w/v) pectinase aided in maintaining a sufficient free water volume for sugar recovery. A laboratory countercurrent extraction experiment utilizing a 1 h steep followed by three extraction (wash) stages produced a high-concentration (131 g/L fermentable sugar) syrup. Overall, sugar recovery efficiency was 88%. The inner stage washing efficiencies were compatible with solution equilibrium calculations, indicating that efficiency was high. The concentrated sugar syrup was fermented to ethanol at high efficiency (86% conversion), and ethanol concentrations in the broth were 7.4% (v/v). Thin stillage contained 233 g SCOD/L, which was converted to biomethane at an efficiency of 90% with a biomethane potential of 297 mL/g SCODdestroyed. Overall, results suggested that a minima of 49 gal (185 L) ethanol and 75 m(3) methane/t hulls (dry whole hull basis) are achievable.

Anaerobic fermentation combined with low-temperature thermal pretreatment for phosphorus-accumulating granular sludge: Release of carbon source and phosphorus as well as hydrogen production potential.

Science.gov (United States)

Zou, Jinte; Li, Yongmei

2016-10-01

Releases of organic compounds and phosphorus from phosphorus-accumulating granular sludge (PGS) and phosphorus-accumulating flocculent sludge (PFS) during low-temperature thermal pretreatment and anaerobic fermentation were investigated. Meanwhile, biogas production potential and microbial community structures were explored. The results indicate that much more soluble chemical oxygen demand (SCOD) and phosphorus were released from PGS than from PFS via low-temperature thermal pretreatment because of the higher extracellular polymeric substances (EPS) content in PGS and higher ratio of phosphorus reserved in EPS. Furthermore, PGS contains more anaerobes and dead cells, resulting in much higher SCOD and volatile fatty acids release from PGS than those from PFS during fermentation. PGS fermentation facilitated the n-butyric acid production, and PGS exhibited the hydrogen production potential during fermentation due to the presence of hydrogen-producing bacteria. Therefore, anaerobic fermentation combined with low-temperature thermal pretreatment can facilitate the recovery of carbon and phosphorus as well as producing hydrogen from PGS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characteristics of fermented plant beverages in southern Thailand

Directory of Open Access Journals (Sweden)

Charernjiratrakul, W.

2005-05-01

Full Text Available The characteristics of fermented plant beverages based on a sensory test, physico-chemical properties, enumeration of microorganisms present and their microbiological quality were investigated. A total of 19 samples of beverages collected from various sources in southern Thailand were examined. It was found that odor, color and clarity and the presence of Cu, Zn, K and Na were mainly dependent on the types of plant used and the additive of sugar or honey. Therefore, the appearance of the beverages was light brown and dark brown. An ester smell was occasionally detected. The fermented plant beverages had sour flavor that developed during fermentation and a little sweetness from residual sugar. The taste was related to the amounts of organic acid and sugar as measured in the ranges of 0.98-7.13% (pH 2.63-3.72 and 0.21-4.20%, respectively. The levels of alcohols measured as ethanol were between 0.03-3.32% and methanol in a range of 0.019 0.084%. Methanol production was dependent on both the fermentation process and the plant used. Total coliforms and Escherichia coli were not detected in any sample, whereas other microbes were detected in some samples as were total bacterial count, lactic acid bacteria, yeast and mold in amounts that differed depending on the fermentation time and also the level of sanitation of the production process.

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.

Isolation and characterization of thermotolerant ethanol-fermenting ...

African Journals Online (AJOL)

Thermotolerant yeasts, which are expected to be applicable for high-temperature fermentation as an economical process, were isolated from four provinces in Laos. Of these yeasts, five isolates exhibited stronger fermentation abilities in a 16% sugars-containing medium of glucose, sucrose, sugarcane or molasses at 40°C ...

Optimization of dilute sulfuric acid pretreatment to maximize combined sugar yield from sugarcane bagasse for ethanol production.

Science.gov (United States)

Benjamin, Y; Cheng, H; Görgens, J F

2014-01-01

Increasing fermentable sugar yields per gram of biomass depends strongly on optimal selection of varieties and optimization of pretreatment conditions. In this study, dilute acid pretreatment of bagasse from six varieties of sugarcane was investigated in connection with enzymatic hydrolysis for maximum combined sugar yield (CSY). The CSY from the varieties were also compared with the results from industrial bagasse. The results revealed considerable differences in CSY between the varieties. Up to 22.7 % differences in CSY at the optimal conditions was observed. The combined sugar yield difference between the best performing variety and the industrial bagasse was 34.1 %. High ratio of carbohydrates to lignin and low ash content favored the release of sugar from the substrates. At mild pretreatment conditions, the differences in bioconversion efficiency between varieties were greater than at severe condition. This observation suggests that under less severe conditions the glucose recovery was largely determined by chemical composition of biomass. The results from this study support the possibility of increasing sugar yields or improving the conversion efficiency when pretreatment optimization is performed on varieties with improved properties.

Production of lactic acid from sucrose: strain selection, fermentation, and kinetic modeling.

Science.gov (United States)

Lunelli, Betânia H; Andrade, Rafael R; Atala, Daniel I P; Wolf Maciel, Maria Regina; Maugeri Filho, Francisco; Maciel Filho, Rubens

2010-05-01

Lactic acid is an important product arising from the anaerobic fermentation of sugars. It is used in the pharmaceutical, cosmetic, chemical, and food industries as well as for biodegradable polymer and green solvent production. In this work, several bacterial strains were isolated from industrial ethanol fermentation, and the most efficient strain for lactic acid production was selected. The fermentation was conducted in a batch system under anaerobic conditions for 50 h at a temperature of 34 degrees C, a pH value of 5.0, and an initial sucrose concentration of 12 g/L using diluted sugarcane molasses. Throughout the process, pulses of molasses were added in order to avoid the cell growth inhibition due to high sugar concentration as well as increased lactic acid concentrations. At the end of the fermentation, about 90% of sucrose was consumed to produce lactic acid and cells. A kinetic model has been developed to simulate the batch lactic acid fermentation results. The data obtained from the fermentation were used for determining the kinetic parameters of the model. The developed model for lactic acid production, growth cell, and sugar consumption simulates the experimental data well.

A review of conversion processes for bioethanol production with a focus on syngas fermentation

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Mamatha Devarapalli

2015-09-01

Full Text Available Bioethanol production from corn is a well-established technology. However, emphasis on exploring non-food based feedstocks is intensified due to dispute over utilization of food based feedstocks to generate bioethanol. Chemical and biological conversion technologies for non-food based biomass feedstocks to biofuels have been developed. First generation bioethanol was produced from sugar based feedstocks such as corn and sugar cane. Availability of alternative feedstocks such as lignocellulosic and algal biomass and technology advancement led to the development of complex biological conversion processes, such as separate hydrolysis and fermentation (SHF, simultaneous saccharification and fermentation (SSF, simultaneous saccharification and co-fermentation (SSCF, consolidated bioprocessing (CBP, and syngas fermentation. SHF, SSF, SSCF, and CBP are direct fermentation processes in which biomass feedstocks are pretreated, hydrolyzed and then fermented into ethanol. Conversely, ethanol from syngas fermentation is an indirect fermentation that utilizes gaseous substrates (mixture of CO, CO2 and H2 made from industrial flue gases or gasification of biomass, coal or municipal solid waste. This review article provides an overview of the various biological processes for ethanol production from sugar, lignocellulosic, and algal biomass. This paper also provides a detailed insight on process development, bioreactor design, and advances and future directions in syngas fermentation.

Ozone pretreatment and fermentative hydrolysis of wheat straw

Science.gov (United States)

Ben'ko, E. M.; Chukhchin, D. G.; Lunin, V. V.

2017-11-01

Principles of the ozone pretreatment of wheat straw for subsequent fermentation into sugars are investigated. The optimum moisture contents of straw in the ozonation process are obtained from data on the kinetics of ozone absorbed by samples with different contents of water. The dependence of the yield of reducing sugars in the fermentative reaction on the quantity of absorbed ozone is established. The maximum conversion of polysaccharides is obtained at ozone doses of around 3 mmol/g of biomass, and it exceeds the value for nonozonated samples by an order of magnitude. The yield of sugar falls upon increasing the dose of ozone. The process of removing lignin from the cell walls of straw during ozonation is visualized by means of scanning electron microscopy.

Bioethanol Production from Raw Juice as Intermediate of Sugar Beet Processing: A Response Surface Methodology Approach

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Stevan Popov

2010-01-01

Full Text Available Response surface methodology (RSM was used for selecting optimal fermentation time and initial sugar mass fraction in cultivation media based on raw juice from sugar beet in order to produce ethanol. Optimal fermentation time and initial sugar mass fraction for ethanol production in batch fermentation by free Saccharomyces cerevisiae cells under anaerobic conditions at the temperature of 30 °C and agitation rate of 200 rpm were estimated to be 38 h and 12.30 % by mass, respectively. For selecting optimal conditions for industrial application, further techno-economic analysis should be performed by using the obtained mathematical representation of the process (second degree polynomial model. The overall fermentation productivity of five different types of yeast was examined and there is no significant statistical difference between them.

Saccharomyces cerevisiae in the Production of Fermented Beverages

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Graeme M Walker

2016-11-01

Full Text Available Alcoholic beverages are produced following the fermentation of sugars by yeasts, mainly (but not exclusively strains of the species, Saccharomyces cerevisiae. The sugary starting materials may emanate from cereal starches (which require enzymatic pre-hydrolysis in the case of beers and whiskies, sucrose-rich plants (molasses or sugar juice from sugarcane in the case of rums, or from fruits (which do not require pre-hydrolysis in the case of wines and brandies. In the presence of sugars, together with other essential nutrients such as amino acids, minerals and vitamins, S. cerevisiae will conduct fermentative metabolism to ethanol and carbon dioxide (as the primary fermentation metabolites as the cells strive to make energy and regenerate the coenzyme NAD+ under anaerobic conditions. Yeasts will also produce numerous secondary metabolites which act as important beverage flavour congeners, including higher alcohols, esters, carbonyls and sulphur compounds. These are very important in dictating the final flavour and aroma characteristics of beverages such as beer and wine, but also in distilled beverages such as whisky, rum and brandy. Therefore, yeasts are of vital importance in providing the alcohol content and the sensory profiles of such beverages. This Introductory Chapter reviews, in general, the growth, physiology and metabolism of S. cerevisiae in alcoholic beverage fermentations.

Fermentative Alcohol Production

DEFF Research Database (Denmark)

Martín, Mariano; Sánchez, Antonio; Woodley, John M.

2018-01-01

In this chapter we present some of key principles of bioreactor design for the production of alcohols by fermentation of sugar and syngas . Due to the different feedstocks, a detailed analysis of the hydrodynamics inside the units , bubble columns or stirred tank reactors , the gas-liquid mass...

Improved enzymatic saccharification of steam exploded cotton stalk using alkaline extraction and fermentation of cellulosic sugars into ethanol.

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Keshav, Praveen K; Naseeruddin, Shaik; Rao, L Venkateswar

2016-08-01

Cotton stalk, a widely available and cheap agricultural residue lacking economic alternatives, was subjected to steam explosion in the range 170-200°C for 5min. Steam explosion at 200°C and 5min led to significant hemicellulose solubilization (71.90±0.10%). Alkaline extraction of steam exploded cotton stalk (SECOH) using 3% NaOH at room temperature for 6h led to 85.07±1.43% lignin removal with complete hemicellulose solubilization. Besides, this combined pretreatment allowed a high recovery of the cellulosic fraction from the biomass. Enzymatic saccharification was studied between steam exploded cotton stalk (SECS) and SECOH using different cellulase loadings. SECOH gave a maximum of 785.30±8.28mg/g reducing sugars with saccharification efficiency of 82.13±0.72%. Subsequently, fermentation of SECOH hydrolysate containing sugars (68.20±1.16g/L) with Saccharomyces cerevisiae produced 23.17±0.84g/L ethanol with 0.44g/g yield. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improved ethanol fermentation of a yeast mutant by C-12 ion beam irradiation

International Nuclear Information System (INIS)

Lu Dong; Liu Qingfang; Wu Xin; Wang Ying; Wang Jufang; Ma Shuang; Li Wenjian

2010-01-01

The yeast Saccharomyces cerevisiae YY was irradiated with 100 MeV/u 12 C 6+ ion beams. After screening,we obtained the mutant strain C03A of high ethanol yield. The influence of fermentation temperature, pH and concentration of sugar on ethanol fermentation were studied. The range analysis and analysis of variance were applied for the result of orthogonal experiments. The optimal ethanol fermentation conditions are: fermentation temperature 35 degree C, pH value 5.0, and sugar concentration 24%. The results of fermentation in the 10 L bioreactor showed that the ethanol fermentation of the mutant strain could be completed in 36 hours, the production of ethanol was to 13.2%(V/V), which means 12 hours faster and 1.6%(V /V) ethanol yield higher than original strain. (authors)

Selection of potential microorganism for sago starch fermentation

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RUTH MELLIAWATI

2006-02-01

Full Text Available 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 Institute of Sciences (LIPI, Cibinong-Bogor were used. The selection step was carried out based on their capability of starch hydrolysis to reducing sugar. The best result indicates that the production of reducing sugar reached the highest 18.485 ppm and amyloglucosidase activities was 3.583 units by KTU-1 strain. The highest total acid obtained was 5.85 mg/mL by Rhizopus IFO.R5442. The cell biomass was obtained between 0.5 to 1.74 g dry weight/100 mL and pH of the final fermentation (72 h were 3.57 to 8.38.

Utilization of concentrate after membrane filtration of sugar beet thin juice for ethanol production.

Science.gov (United States)

Kawa-Rygielska, Joanna; Pietrzak, Witold; Regiec, Piotr; Stencel, Piotr

2013-04-01

The subject of this study was to investigate the feasibility of the concentrate obtained after membrane ultrafiltration of sugar beet thin juice for ethanol production and selection of fermentation conditions (yeast strain and media supplementation). Resulting concentrate was subjected to batch ethanol fermentation using two strains of Saccharomyces cerevisiae (Ethanol Red and Safdistill C-70). The effect of different forms of media supplementation (mineral salts: (NH4)2SO4, K2HPO4, MgCl2; urea+Mg3(PO4)2 and yeast extract) on the fermentation course was also studied. It was stated that sugar beet juice concentrate is suitable for ethanol production yielding, depending on the yeast strain, ca. 85-87 g L(-1) ethanol with ca. 82% practical yield and more than 95% of sugars consumption after 72 h of fermentation. Nutrients enrichment further increased ethanol yield. The best results were obtained for media supplemented with urea+Mg3(PO4)2 yielding 91.16-92.06 g L(-1) ethanol with practical yield ranging 84.78-85.62% and full sugars consumption. Copyright © 2013. Published by Elsevier Ltd.

Contamination of alcoholic molasses mashes in respect to continuous fermentation

Energy Technology Data Exchange (ETDEWEB)

Zvacek, O; Barta, J; Vintika, J

1957-01-01

Contamination (I) of molasses mashes during and after continuous alcohol fermentation was caused by species of Lactobacillus, belonging both to the hetero and homofermentative type. The latter types were not found in discontinuous fermentation. I affected considerably the content of residual sugar (II) in the fermented molasses mash, reaching in some cases zero values. II thus cannot be an objective criterion of the fermentation process.

Transcriptional and metabolic effects of glucose on Streptococcus pneumoniae sugar metabolism

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Laura ePaixão

2015-10-01

Full Text Available Streptococcus pneumoniae is a strictly fermentative human pathogen that relies on carbohydrate metabolism to generate energy for growth. The nasopharynx colonised by the bacterium is poor in free sugars, but mucosa lining glycans can provide a source of sugar. In blood and inflamed tissues glucose is the prevailing sugar. As a result during progression from colonisation to disease S. pneumoniae has to cope with a pronounced shift in carbohydrate nature and availability. Thus, we set out to assess the pneumococcal response to sugars found in glycans and the influence of glucose (Glc on this response at the transcriptional, physiological and metabolic levels. Galactose (Gal, N-acetylglucosamine (GlcNAc and mannose (Man affected the expression of 8 to 14% of the genes covering cellular functions including central carbon metabolism and virulence. The pattern of end-products as monitored by in vivo 13C-NMR is in good agreement with the fermentation profiles during growth, while the pools of phosphorylated metabolites are consistent with the type of fermentation observed (homolactic vs. mixed and regulation at the metabolic level. Furthermore, the accumulation of α-Gal6P and Man6P indicate metabolic bottlenecks in the metabolism of Gal and Man, respectively. Glc added to cells actively metabolizing other sugar(s was readily consumed and elicited a metabolic shift towards a homolactic profile. The transcriptional response to Glc was large (over 5% of the genome. In central carbon metabolism (most represented category, Glc exerted mostly negative regulation. The smallest response to Glc was observed on a sugar mix, suggesting that exposure to varied sugars improves the fitness of S. pneumoniae. The expression of virulence factors was negatively controlled by Glc in a sugar-dependent manner. Overall, our results shed new light on the link between carbohydrate metabolism, adaptation to host niches and virulence.

Transcriptional and metabolic effects of glucose on Streptococcus pneumoniae sugar metabolism.

Science.gov (United States)

Paixão, Laura; Caldas, José; Kloosterman, Tomas G; Kuipers, Oscar P; Vinga, Susana; Neves, Ana R

2015-01-01

Streptococcus pneumoniae is a strictly fermentative human pathogen that relies on carbohydrate metabolism to generate energy for growth. The nasopharynx colonized by the bacterium is poor in free sugars, but mucosa lining glycans can provide a source of sugar. In blood and inflamed tissues glucose is the prevailing sugar. As a result during progression from colonization to disease S. pneumoniae has to cope with a pronounced shift in carbohydrate nature and availability. Thus, we set out to assess the pneumococcal response to sugars found in glycans and the influence of glucose (Glc) on this response at the transcriptional, physiological, and metabolic levels. Galactose (Gal), N-acetylglucosamine (GlcNAc), and mannose (Man) affected the expression of 8 to 14% of the genes covering cellular functions including central carbon metabolism and virulence. The pattern of end-products as monitored by in vivo (13)C-NMR is in good agreement with the fermentation profiles during growth, while the pools of phosphorylated metabolites are consistent with the type of fermentation observed (homolactic vs. mixed) and regulation at the metabolic level. Furthermore, the accumulation of α-Gal6P and Man6P indicate metabolic bottlenecks in the metabolism of Gal and Man, respectively. Glc added to cells actively metabolizing other sugar(s) was readily consumed and elicited a metabolic shift toward a homolactic profile. The transcriptional response to Glc was large (over 5% of the genome). In central carbon metabolism (most represented category), Glc exerted mostly negative regulation. The smallest response to Glc was observed on a sugar mix, suggesting that exposure to varied sugars improves the fitness of S. pneumoniae. The expression of virulence factors was negatively controlled by Glc in a sugar-dependent manner. Overall, our results shed new light on the link between carbohydrate metabolism, adaptation to host niches and virulence.

Gamma radiation in some microbiological and biochemical parameters of ethanolic fermentation

International Nuclear Information System (INIS)

Alcarde, Andre Ricardo

2000-01-01

The objective of this work was to evaluate the effect of gamma radiation in reducing the bacterial population of the sugar cane must and verify its influence in the ethanolic fermentation. For this purpose, some microbiological and biochemical parameters of the ethanolic fermentation were analyzed, such as bacterial count; viability, replication and living replicates of the yeast; p H, acidity (total and volatile), glycerol and production of organic acids (acetic, lactic and succinic) during the fermentation; and fermentative yield. Bacteria of the genera Bacillus and Lactobacillus are the most common contaminants of the ethanolic fermentation and they might cause a decrease in the fermentative yield. The ionizing radiations may affect the microorganisms altering the DNA of the cells, which lose the ability to reproduce themselves and die. The experimental design was in randomized blocks (three) with one replicate in each block. The must was sugar-cane juice with approximately 5% of total reducing sugar. Bacteria of the following species were tested: Bacillus subtilis, Bacillus coagulans, Lactobacillus plantarum and Lactobacillus fermentum. The experiments were the inoculation of each bacteria separately in the must, the inoculation of the mixture of the four bacteria in the must and the use of natural sugar-cane juice with its own contaminating microorganisms. The contaminated must was irradiated with the doses of 0.0 (control), 2.0,4.0, 6.0, 8.0 and 10.0 kGy of gamma radiation (60-Cobalt) at an average rate of 2.0 kGy/h. After the irradiation, the fermentation of the must was carried out using the yeast Saccharomyces cerevisiae (Fleischmann). It was also accomplished an experiment with the inoculation of the mixture of the four bacteria in the must and, instead of using gamma radiation to decontaminate the must, it was used the antimicrobial Kamoran ID in the concentration of 3 ppm. The effects of the irradiation of the must were: reduction of the bacterial

Combined enzymatic hydrolysis and fermentation of hemicellulose to 2,3-butanediol

Energy Technology Data Exchange (ETDEWEB)

Yu, E.K.C.; Deschatelets, L.; Saddler, J.N.

1984-06-01

Hemicellulose-rich fractions from several agricultural residues were converted to 2,3-butanediol by a combined enzymatic hydrolysis and fermentation process. Culture filtrates from Trichoderma harzianum E58 were used to hydrolyze the substrates while Klebsiella pneumoniae fermented the liberated sugars to 2,3-butanediol. Approximately 50-60% of a 5% (w/v) xylan preparation could be hydrolyzed and quantitatively converted to 2,3-butanediol using this procedure. Although enzymatic hydrolysis was optimal at pH 5.0 and 50/sup 0/C, the combined hydrolysis and fermentation was most efficient at pH 6.5 and 30/sup 0/C. Combined hydrolysis and fermentation resulted in butanediol levels that were 20-40% higher than could be obtained with a separate hydrolysis and fermentation process. The hemicellulose-rich water-soluble fractions obtained from a variety of steam-exploded agricultural residues could be readily used by the combined hydrolysis and fermentation approach resulting in butanediol yields of 0.4-0.5 g/g of reducing sugar utilized.

Utilization of residue from cassava starch processing for production of fermentable sugar by enzymatic hydrolysis

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Luciana Reis Fontinelle SOUTO

Full Text Available Abstract The aim of this study was to characterize and perform enzymatic hydrolysis of cassava peeling residue (peel and inner peel, mainly composed of peels and small pieces. Residue was sanitized, dried at 55 °C for 24 hours and ground. The obtained flour showed pH of 4.85; 72.53 g 100 g–1 moisture; 5.18 mL 1M NaOH 100 g–1 acidity; 60.68 g 100 g–1 starch; 1.08 g 100 g–1 reducing sugar; 1.63 g 100g–1 ash; 0.86 g 100 g–1 lipid and 3.97 g 100 g–1 protein. Enzymatic hydrolysis was carried out by means of rotational central composite design, analyzing the effects of concentrations of α-amylase enzyme (10 to 50 U g starch–1, and the amyloglucosidase enzyme (80 to 400 U g starch–1 on variable responses: percent conversion of starch into reducing sugars (RSC and soluble solid content (SS. Highest values of RSC (110% and SS (12 °Brix were observed when using the maximum concentration of amyloglucosidase and throughout the concentration range of α-amylase. Enzymatic hydrolysis of cassava peel is feasible and allows the use of hydrolysate in fermentation processes for the production of various products, such as alcoholic drinks, vinegar, among others.

Utilization of residue from cassava starch processing for production of fermentable sugar by enzymatic hydrolysis

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Luciana Reis Fontinelle SOUTO

2016-01-01

Full Text Available Abstract The aim of this study was to characterize and perform enzymatic hydrolysis of cassava peeling residue (peel and inner peel, mainly composed of peels and small pieces. Residue was sanitized, dried at 55 °C for 24 hours and ground. The obtained flour showed pH of 4.85; 72.53 g 100 g–1 moisture; 5.18 mL 1M NaOH 100 g–1 acidity; 60.68 g 100 g–1 starch; 1.08 g 100 g–1 reducing sugar; 1.63 g 100g–1 ash; 0.86 g 100 g–1 lipid and 3.97 g 100 g–1 protein. Enzymatic hydrolysis was carried out by means of rotational central composite design, analyzing the effects of concentrations of α-amylase enzyme (10 to 50 U g starch–1, and the amyloglucosidase enzyme (80 to 400 U g starch–1 on variable responses: percent conversion of starch into reducing sugars (RSC and soluble solid content (SS. Highest values of RSC (110% and SS (12 °Brix were observed when using the maximum concentration of amyloglucosidase and throughout the concentration range of α-amylase. Enzymatic hydrolysis of cassava peel is feasible and allows the use of hydrolysate in fermentation processes for the production of various products, such as alcoholic drinks, vinegar, among others.

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

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Elham Aslankoohi

Full Text Available 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.

Mechano-Enzymatic Deconstruction with a New Enzymatic Cocktail to Enhance Enzymatic Hydrolysis and Bioethanol Fermentation of Two Macroalgae Species

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Sameh Amamou

2018-01-01

Full Text Available The aim of this study was to explore the efficiency of a mechano-enzymatic deconstruction of two macroalgae species for sugars and bioethanol production, by using a new enzymatic cocktail (Haliatase and two types of milling modes (vibro-ball: VBM and centrifugal milling: CM. By increasing the enzymatic concentration from 3.4 to 30 g/L, the total sugars released after 72 h of hydrolysis increased (from 6.7 to 13.1 g/100 g TS and from 7.95 to 10.8 g/100 g TS for the green algae U. lactuca and the red algae G. sesquipedale, respectively. Conversely, total sugars released from G. sesquipedale increased (up to 126% and 129% after VBM and CM, respectively. The best bioethanol yield (6 geth/100 g TS was reached after 72 h of fermentation of U. lactuca and no increase was obtained after centrifugal milling. The latter led to an enhancement of the ethanol yield of G. sesquipedale (from 2 to 4 g/100 g TS.

Modeling as a tool for process control: alcoholic fermentation

Energy Technology Data Exchange (ETDEWEB)

Tayeb, A M; Ashour, I A; Mostafa, N A [El-Minia Univ. (EG). Faculty of Engineering

1991-01-01

The results of the alcoholic fermentation of beet sugar molasses and wheat milling residues (Akalona) were fed into a computer program. Consequently, the kinetic parameters for these fermentation reactions were determined. These parameters were put into a kinetic model. Next, the model was tested, and the results obtained were compared with the experimental results of both beet molasses and Akalona. The deviation of the experimental results from the results obtained from the model was determined. An acceptable deviation of 1.2% for beet sugar molasses and 3.69% for Akalona was obtained. Thus, the present model could be a tool for chemical engineers working in fermentation processes both with respect to the control of the process and the design of the fermentor. (Author).

Dynamics of chemical elements in the fermentation process of ethanol production

International Nuclear Information System (INIS)

Nepomuceno, N.; Fernandes, E.A.N.; Bacchi, M.A.

1997-01-01

Brazil has become the largest producer of biomass ethanol derived from sugar cane. The industrial production is based on the fermentation of sugar cane juice by yeast, inside of large volume vats, in a fed-batch process that recycles yeast cells. To study the dynamics of chemical elements in each operating cycle, five stages of the fermentation process were considered: must, yeast suspension, wine, non-yeast wine and yeast cream. For this, a mass balance of the terrigenous elements, Ce, Co, Cs, Eu, Fe, Hf, La, Na, Sc, Sm, and Th, and the sugar cane plant elements, Br, K, Rb, and Zn, were established in fermentation vats of an industrial scale unit, with sampling undertaken during different climatic conditions (dry and rainy periods). A similar distribution of the sugar cane characteristics elements was found for the stages analysed, while for the terrigenous elements a trend of accumulation in the yeast cream was observed. Preferential absorption of Br, K, Rb, and Zn by yeast cells was indicated by the smaller concentrations observed in yeast suspension than in yeast cream. (author)

Modeling a one-stage continuous ethanol fermentation

Energy Technology Data Exchange (ETDEWEB)

Michalski, H; Wieczorek, A

1974-01-01

Kinetics of the fermentation process carried out with Saccharomyces cerevisiae hybrid G-67 on synthetic media at different initial concentrations of sugar and mixing speed have been determined. No significant effect of mixing (Reynolds No. 1915-7760) and initial sugar concentrations within 50 to 150 g/l was found on the biomass and final ethanol concentration or on the amount of sugar consumed. The optimum dilution rate was 0.10 to 0.20 h/sup -1/. Kinetic equations for sugar and ethanol concentration changes in the process are given.

Prospects of utilization of sugar beet carbohydrates for biological hydrogen production in the EU

NARCIS (Netherlands)

Panagiotopoulos, I.A.; Bakker, R.R.; Vrije, de G.J.; Urbaniec, K.; Koukios, E.G.; Claassen, P.A.M.

2010-01-01

Hydrogen can be produced through dark anaerobic fermentation using carbohydrate-rich biomass, and through photofermentation using the organic acids produced from dark fermentation. Sugar beet is an ideal energy crop for fermentative production of hydrogen in the EU due to its environmental profile

Mixed sugar fermentation by Pichia stipitis, Sacharomyces ...

African Journals Online (AJOL)

Administrator

2007-05-02

May 2, 2007 ... A yeast strain with higher rates and yields in the fermentation of ... highest Qpmax (1.09 gl-1h-1) and substrate utilization efficiency (E,>99%). ... P. stipitis to reach the concentration higher than 30 g/l ethanol concentration.

Butanol-acetone fermentation of sugar-cane juice

Energy Technology Data Exchange (ETDEWEB)

Perdomo, E V

1958-01-01

Sixteen new varieties of Clostridium acetobutylicum of varying activity were isolated from different sources. The most active one was obtained from sugar-cane roots. The effects of 86 additives were studied. The following formulation gave a 32% yield (with respect to sucrose) of solvent mixture (73% BuOH, 19 to 23% acetone, and 3 to 4% EtOH) sugar-cane juice (I) (20/sup 0/ Brix) 250 ml, ground Vicia sativa 1 g, KH/sub 2/PO/sub 4/ 2.5 g, CaCO/sub 3/ 4 g, H/sub 2/O 1000 ml; the pH of this solution was 5.6 to 6.0. Unclarified, it was inverted by invertase; the other components were added and the mixture was sterilized (20 minutes, 15 pounds).

Ethanol production from alfalfa fiber fractions by saccharification and fermentation

Energy Technology Data Exchange (ETDEWEB)

Sreenath, H.K. [University of Wisconsin, Madison, WI (United States). Dept. of Biological Systems Engineering; USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Koegel, R.G. [US Department of Agriculture, Madison, WI (United States). Dairy Forage Research Center; Moldes, A.B. [USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Universidade de Vigo, Ourense (Spain); Jeffries, T.W. [USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Straub, R.J. [University of Wisconsin, Madison, WI (United States). Dept. of Biological Systems Engineering

2001-07-01

This work describes ethanol production from alfalfa fiber using separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) with and without liquid hot water (LHW) pretreatment. Candida shehatae FPL-702 produced 5 and 6.4 g/l ethanol with a yield of 0.25 and 0.16 g ethanol/g sugar respectively by SHF and SSF from alfalfa fiber without pretreatment. With LHW pretreatment using SSF, C. shehatae FPL-702 produced 18.0 g/l ethanol, a yield of 0.45 g ethanol/g sugar from cellulosic solids or 'raffinate'. Using SHF, it produced 9.6 g/l ethanol, a yield of 0.47 g ethanol/g sugar from raffinate. However, the soluble extract fraction containing hemicelluloses was poorly fermented in both SHF and SSF due to the presence of inhibitors. Addition of dilute acid during LHW pretreatment of alfalfa fiber resulted in fractions that were poorly saccharified and fermented. These results show that unpretreated alfalfa fiber produced a lower ethanol yield. Although LHW pretreatment can increase ethanol production from raffinate fiber fractions, it does not increase production from the hemicellulosic and pectin fractions. (author)

What is alcoholic fermentation? A study about the alcoholic fermentation conception through the history

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C.A. F. Cardoso

2004-05-01

Full Text Available This work shows the historical development of the alcoholic fermentation conception, based on expe-rimental results obtained from European scientists, from Renascence to the beginning of 20th century(1930. From this, ve concepts were identied for the phenomenon: putrefactive, spiritual, chemical,biological and biochemical. The current conception of alcoholic fermentation was also evaluated. Forthis proposal, three groups of teachers were interviewed through the question? What is alcoholicfermentation? The P group (pilot, n=12 made of professionals that teach on secondary and highschools, group A composed of PhDs from the Center of Technology Education - NUTES (n=9 andgroup B from Department of Medical Biochemistry (called group B, n=41 both of Federal Universityof Rio de Janeiro, respectively. Key words associated with the fermentative process were identiedidentify in the interviewees answers. The group A components mentioned only six key words andpointed out the alcoholic fermentation products. Dierently, subjects from P and B groups cited ahigher number and also more unusual key words (n = 9 and 12, respectively. We also analyzedtheir answers throughout fermentative descriptive words (sugar, alcohol, carbon dioxide, anaerobic,yeast and ATP. These words were established after an evaluation of alcoholic fermentation conceptstated in the Biology/Biochemistry books most adopted in high schools and Universities. Our analysisshowed that group A used only three descriptive words (sugar, alcohol and yeast while componentsof group B used all the selected descriptive words. However, only one interviewee used all the sixwords together. From this analysis, we proposed that the chemical concept of alcoholic fermentationprevailed on the other concepts found on the historical research (spiritual, putrefactive, biological ebiochemical.

[Continuous ethanol fermentation coupled with recycling of yeast flocs].

Science.gov (United States)

Wang, Bo; Ge, Xu-Meng; Li, Ning; Bai, Feng-Wu

2006-09-01

A continuous ethanol fermentation system composed of three-stage tanks in series coupled with two sedimentation tanks was established. A self-flocculating yeast strain developed by protoplast fusion from Saccharomyces cerevisiae and Schizosaccharomyces pombe was applied. Two-stage enzymatic hydrolysate of corn powder containing 220g/L of reducing sugar, supplemented with 1.5g/L (NH4)2HPO4 and 2.5g/L KH2PO4, was used as the ethanol fermentation substrate and fed into the first fermentor at the dilution rate of 0.057h(-1). The yeast flocs separated by sedimentation were recycled into the first fermentor as two different models: activation-recycle and direct recycle. The quasi-steady states were obtained for both operation models after the fermentation systems experienced short periods of transitions. Activation process helped enhance the performance of ethanol fermentation at the high dilution rates. The broth containing more than 101g/L ethanol, 3.2g/L residual reducing sugar and 7.7g/L residual total sugar was produced. The ethanol productivity was calculated to be 5.77g/(L x h), which increased by more than 70% compared with that achieved in the same tank in series system without recycling of yeast cells.

Phenotypic characterisation of Saccharomyces spp. yeast for tolerance to stresses encountered during fermentation of lignocellulosic residues to produce bioethanol

Science.gov (United States)

2014-01-01

Background During industrial fermentation of lignocellulose residues to produce bioethanol, microorganisms are exposed to a number of factors that influence productivity. These include inhibitory compounds produced by the pre-treatment processes required to release constituent carbohydrates from biomass feed-stocks and during fermentation, exposure of the organisms to stressful conditions. In addition, for lignocellulosic bioethanol production, conversion of both pentose and hexose sugars is a pre-requisite for fermentative organisms for efficient and complete conversion. All these factors are important to maximise industrial efficiency, productivity and profit margins in order to make second-generation bioethanol an economically viable alternative to fossil fuels for future transport needs. Results The aim of the current study was to assess Saccharomyces yeasts for their capacity to tolerate osmotic, temperature and ethanol stresses and inhibitors that might typically be released during steam explosion of wheat straw. Phenotypic microarray analysis was used to measure tolerance as a function of growth and metabolic activity. Saccharomyces strains analysed in this study displayed natural variation to each stress condition common in bioethanol fermentations. In addition, many strains displayed tolerance to more than one stress, such as inhibitor tolerance combined with fermentation stresses. Conclusions Our results suggest that this study could identify a potential candidate strain or strains for efficient second generation bioethanol production. Knowledge of the Saccharomyces spp. strains grown in these conditions will aid the development of breeding programmes in order to generate more efficient strains for industrial fermentations. PMID:24670111

Chemical elements dynamic in the fermentation process of ethanol producing

International Nuclear Information System (INIS)

Nepomuceno, N.; Nadai Fernandes, E.A. de; Bacchi, M.A.

1994-01-01

This paper provides useful information about the dynamics of chemical elements analysed by instrumental neutron activation analysis (INAA) and, found in the various segments of the fermentation process of producing ethanol from sugar cane. For this, a mass balance of Ce, Co, Cs, Eu, Fe, Hf, La, Sc, Sm, and Th, terrigenous elements, as well as Br, K, Rb, and Zn, sugar cane plant elements, has been demonstrated for the fermentation vats in industrial conditions of ethanol production. (author). 10 refs, 4 figs, 1 tab

The availability of a lactose medium for tea fungus culture and Kombucha fermentation

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Markov S.L.

2012-01-01

Full Text Available Kombucha is a traditional beverage that is prepared by fermenting sucrose-sweetened black tea. A medium is inoculated with a cellulose pellicle (popularly known as a “tea fungus” or fermentation brought from previous cultivation process. Our aim was to test the possibility of obtaining a Kombucha beverage using different concentration of lactose as an alternative source of C-atoms. A traditional medium sweetened with sucrose or without sugar was used as control. Without lactose-fermenting yeast strains in tea fungus, lactose is not an adequate alternative source of the C-atom for Kombucha fermentation because it is not possible to obtain Kombucha with an appropriate acidity during a seven-day fermentation. Compared with the traditional medium, fermentation is significantly slower with high differences in acid content. In unsweetened tea inoculated with the beverage obtained from a previous traditional process, Kombucha fermentation processes and produces a beverage without sugar and alcohol. [Projekat Ministarstva nauke Republike Srbije, br. TR 31044

Effect of Germination and Fermentation on Carbohydrate Composition of Australian Sweet Lupin and Soybean Seeds and Flours.

Science.gov (United States)

Kaczmarska, Kornelia T; Chandra-Hioe, Maria V; Zabaras, Dimitrios; Frank, Damian; Arcot, Jayashree

2017-11-22

This study investigated the effect of germination and fermentation on the composition of carbohydrates in Australian sweet lupin. Specifically, the amount of sugars (sucrose, fructose, and glucose), starch, oligosaccharides (verbascose, stachyose, and raffinose), and dietary fiber were measured in germinated lupin seeds and fermented lupin flour, and compared with those in soy. High performance liquid chromatography coupled with refractive index was employed for quantitation of sugars, starch, and oligosaccharides, and gas chromatography coupled with a flame ionization detector was used for quantitation of simple sugars in total, and soluble, and insoluble dietary fiber. The enzyme activities of α-amylase and α-glucosidase were compared before and after germination or fermentation. The α-amylase activity in germinated lupin increased to  ∼17 nmol/mL/min/0.1 g and in germinated soy∼32; in fermented lupin, the activity increased to ∼52, while in fermented soy it decreased to ∼20. In general, germination or fermentation decreased the oligosaccharide content, and increased the total sugar in samples (p Fermentation with yogurt culture lowered the content of total oligosaccharides due to 94% decrease in stachyose. Total oligosaccharides in soy flour prior to fermentation were 180 mg/g and significantly decreased to ∼124 mg/g in fermented soy. Germination did not affect the starch content. There was no significant change in the amounts of total, soluble, and insoluble dietary fiber after germination or fermentation of lupin except for galactose, which was significantly reduced in germinated lupin seeds. Soluble dietary fiber in germinated soy significantly increased. Germination and fermentation are simple and effective techniques to reduce the oligosaccharides while maintaining the composition of dietary fibers.

The addition of zeolite adsorbents and calcium oxide on purification of bioethanol from sugar palm (arenga pinnata merr)

Science.gov (United States)

Herlina, Netti; Siska Dewi Harahap, Ici

2018-03-01

Bioethanol (C2H5OH) is a biochemical liquid produced by microorganisms through fermentation process on sugar molecules from carbohydrates. Bioethanol is a fuel of vegetable oil that has similar properties to premium. With its main product of palm juice, Sugar palm (Arenga pinnata) is a potential source of sugar and carbohydrate for bioethanol production. Production of palm juice can reach up to 12-14 liters/tree/day with total sugar content in palm juice ranges from 12-15%. The purpose of this research was to produce highly-concentrated bioethanol from palm juice through fermentation proccess to subtitude fossil fuel. This study was conducted with three stages of treatment, namely: the fermentation of palm juice, distillation of bioethanol, and purification of bioethanol with the addition of adsorbent zeolite and calcium oxide.

Assessment of hazelnut husk as a lignocellulosic feedstock for the production of fermentable sugars and lignocellulolytic enzymes.

Science.gov (United States)

Pinar, Orkun; Karaosmanoğlu, Kübra; Sayar, Nihat Alpagu; Kula, Ceyda; Kazan, Dilek; Sayar, Ahmet Alp

2017-12-01

The present work focuses firstly on the evaluation of the effect of laccase on enzymatic hydrolysis of hazelnut husk which is one of the most abundant lignocellulosic agricultural residues generated in Turkey. In this respect, the co-enzymatic treatment of hazelnut husk by cellulase and laccase, without a conventional pretreatment step is evaluated. Using 2.75 FPU/g substrate (40 g/L substrate) and a ratio of 131 laccase U/FPU achieved the highest reducing sugars concentration. Gas chromatography mass spectrometry confirmed that the hydrolysate was composed of glucose, xylose, mannose, arabinose and galactose. The inclusion of laccase in the enzyme mixture [carboxymethyl cellulase (CMCase) and β-glucosidase] increased the final glucose content of the reducing sugars from 20 to 50%. Therefore, a very significant increase in glucose content of the final reducing sugars concentration was obtained by laccase addition. Furthermore, the production of cellulases and laccase by Pycnoporus sanguineus DSM 3024 using hazelnut husk as substrate was also investigated. Among the hazelnut husk concentrations tested (1.5, 6, 12, 18 g/L), the highest CMCase concentration was obtained using 12 g/L husk concentration on the 10th day of fermentation. Besides CMCase, P. sanguineus DSM 3024 produced β-glucosidase and laccase using hazelnut husk as carbon source. In addition to CMCase and β-glucosidase, the highest laccase activity measured was 2240 ± 98 U/L (8.89 ± 0.39 U/mg). To the best of our knowledge, this is the first study to report hazelnut husk hydrolysis in the absence of pretreatment procedures.

Characteristics of an immobilized yeast cell system using very high gravity for the fermentation of ethanol.

Science.gov (United States)

Ji, Hairui; Yu, Jianliang; Zhang, Xu; Tan, Tianwei

2012-09-01

The characteristics of ethanol production by immobilized yeast cells were investigated for both repeated batch fermentation and continuous fermentation. With an initial sugar concentration of 280 g/L during the repeated batch fermentation, more than 98% of total sugar was consumed in 65 h with an average ethanol concentration and ethanol yield of 130.12 g/L and 0.477 g ethanol/g consumed sugar, respectively. The immobilized yeast cell system was reliable for at least 10 batches and for a period of 28 days without accompanying the regeneration of Saccharomyces cerevisiae inside the carriers. The multistage continuous fermentation was carried out in a five-stage column bioreactor with a total working volume of 3.75 L. The bioreactor was operated for 26 days at a dilution rate of 0.015 h(-1). The ethanol concentration of the effluent reached 130.77 g/L ethanol while an average 8.18 g/L residual sugar remained. Due to the high osmotic pressure and toxic ethanol, considerable yeast cells died without regeneration, especially in the last two stages, which led to the breakdown of the whole system of multistage continuous fermentation.

Engineering furfural tolerance in Escherichia coli improves the fermentation of lignocellulosic sugars into renewable chemicals.

Science.gov (United States)

Wang, Xuan; Yomano, Lorraine P; Lee, James Y; York, Sean W; Zheng, Huabao; Mullinnix, Michael T; Shanmugam, K T; Ingram, Lonnie O

2013-03-05

Pretreatments such as dilute acid at elevated temperature are effective for the hydrolysis of pentose polymers in hemicellulose and also increase the access of enzymes to cellulose fibers. However, the fermentation of resulting syrups is hindered by minor reaction products such as furfural from pentose dehydration. To mitigate this problem, four genetic traits have been identified that increase furfural tolerance in ethanol-producing Escherichia coli LY180 (strain W derivative): increased expression of fucO, ucpA, or pntAB and deletion of yqhD. Plasmids and integrated strains were used to characterize epistatic interactions among traits and to identify the most effective combinations. Furfural resistance traits were subsequently integrated into the chromosome of LY180 to construct strain XW129 (LY180 ΔyqhD ackA::PyadC'fucO-ucpA) for ethanol. This same combination of traits was also constructed in succinate biocatalysts (Escherichia coli strain C derivatives) and found to increase furfural tolerance. Strains engineered for resistance to furfural were also more resistant to the mixture of inhibitors in hemicellulose hydrolysates, confirming the importance of furfural as an inhibitory component. With resistant biocatalysts, product yields (ethanol and succinate) from hemicellulose syrups were equal to control fermentations in laboratory media without inhibitors. The combination of genetic traits identified for the production of ethanol (strain W derivative) and succinate (strain C derivative) may prove useful for other renewable chemicals from lignocellulosic sugars.

Semi-solid microbial fermentation of rice and wheat straw for protein enrichment and increased digestibility

Energy Technology Data Exchange (ETDEWEB)

Balasubramanya, R.H.; Bhatawdekar, S.P.

1980-12-01

Rice and wheat straws were hydrolyzed in various concentrations of sulfuric acid at different temperatures and different water: substrate ratios. The maximum amount of sugars of about 30-34% was released when heated at 121 degrees C with 0.5 N H2SO4 at a water: substrate ratio of 3:1. The pH of the hydrolyzed straws was raised to 5.0-5.5 with 5 N NH4OH. Such ammoniated straws were inoculated with the cultures of Penicillium funiculosum Thom. and Candida utilis (Henneb.) Lodder and Kreger-van Rij, and fermentation was carried out on semi-solid substrate for 5-7 days at room temperature. The fermentation resulted in 37-180% increase in crude protein, 23-100% increase in crude fat and 20-30% increase in the digestibility. (Refs. 29).

Transcriptional and metabolic effects of glucose on Streptococcus pneumoniae sugar metabolism

NARCIS (Netherlands)

Paixão, Laura; Caldas, José; Kloosterman, Tomas G; Kuipers, Oscar P; Vinga, Susana; Neves, Ana R

2015-01-01

Streptococcus pneumoniae is a strictly fermentative human pathogen that relies on carbohydrate metabolism to generate energy for growth. The nasopharynx colonized by the bacterium is poor in free sugars, but mucosa lining glycans can provide a source of sugar. In blood and inflamed tissues glucose

Evaluation of sugar yeast consumption by measuring electrical medium resistance

Directory of Open Access Journals (Sweden)

Martin Lucas Zamora

2013-12-01

Full Text Available The real-time monitoring of alcoholic fermentation (sugar consumption is very important in industrial processes. Several techniques (i.e., using a biosensor have been proposed to realize this goal. In this work, we propose a new method to follow sugar yeast consumption. This novel method is based on the changes in the medium resistance (Rm that are induced by the CO2 bubbles produced during a fermentative process. We applied a 50-mV and 700-Hz signal to 75 ml of a yeast suspension in a tripolar cell. A gold electrode was used as the working electrode, whereas an Ag/AgCl electrode and a stainless-steel electrode served as the reference and counter electrodes, respectively. We then added glucose to the yeast suspension and obtained a 700% increase in the Rm after 8 minutes. The addition of sucrose instead of glucose as the carbon source resulted in a 1200% increase in the Rm. To confirm that these changes are the result of CO2 bubbles in the fermentation medium, we designed a tetrapolar cell in which CO2 gas was insufflated at the bottom of the cell and concluded that the changes were due to CO2 bubbles produced during the fermentation. Consequently, this new method is a low-cost and rapid technology to follow the sugar consumption in yeast.

Sequential saccharification of corn fiber and ethanol production by the brown rot fungus Gloeophyllum trabeum.

Science.gov (United States)

Rasmussen, M L; Shrestha, P; Khanal, S K; Pometto, A L; Hans van Leeuwen, J

2010-05-01

Degradation of lignocellulosic biomass to sugars through a purely biological process is a key to sustainable biofuel production. Hydrolysis of the corn wet-milling co-product-corn fiber-to simple sugars by the brown rot fungus Gloeophyllum trabeum was studied in suspended-culture and solid-state fermentations. Suspended-culture experiments were not effective in producing harvestable sugars from the corn fiber. The fungus consumed sugars released by fungal extracellular enzymes. Solid-state fermentation demonstrated up to 40% fiber degradation within 9days. Enzyme activity assays on solid-state fermentation filtrates confirmed the involvement of starch- and cellulose-degrading enzymes. To reduce fungal consumption of sugars and to accelerate enzyme activity, 2- and 3-d solid-state fermentation biomasses (fiber and fungus) were submerged in buffer and incubated at 37 degrees C without shaking. This anaerobic incubation converted up to almost 11% of the corn fiber into harvestable reducing sugars. Sugars released by G. trabeum were fermented to a maximum yield of 3.3g ethanol/100g fiber. This is the first report, to our knowledge, of G. trabeum fermenting sugar to ethanol. The addition of Saccharomyces cerevisiae as a co-culture led to more rapid fermentation to a maximum yield of 4.0g ethanol/100g fiber. The findings demonstrate the potential for this simple fungal process, requiring no pretreatment of the corn fiber, to produce more ethanol by hydrolyzing and fermenting carbohydrates in this lignocellulosic co-product. Copyright 2010 Elsevier Ltd. All rights reserved.

Elucidating Flux Regulation of the Fermentation Modes of Lactococcus lactis

DEFF Research Database (Denmark)

Chan, Siu Hung Joshua

an important subject for basic research in cellular metabolism because L. lactis exhibits an interesting metabolic shift. Under anaerobic conditions, on fast fermentable sugars, L. lactis produces lactate as the primary product, known as homolactic fermentation but on slowly fermentable sugars, significant...... amounts of formate, acetate and ethanol are formed, known as mixed-acid fermentation. This shift is termed the mixedacid shift. This type of shift between a low-yield and a high-yield metabolism has drawn a lot of research focus and has similarly been observed in other bacteria, yeast and even tumor cells....... Efforts have been put to find out the mechanism regulating the mixed-acid shift as well as to answer questions such as why L. lactis prefers such a switch. Until now, some pieces of evidence have been reported and several factors and models have been proposed as the keys to regulating the shift, including...

Koji for alcoholic fermentation

Energy Technology Data Exchange (ETDEWEB)

Ikeda, T; Ogihara, H

1956-06-25

The pressed cake of fermented alcohol mash was used for preparing koji. The cake included considerable amounts of sugar, N-containing materials, enzymes, and vitamins, and gave a high-quality koji for alcohol fermentation. For example, the cake can be mixed with wheat bran and rice husks in the proportion 6:5:0 or 6:2:3 to make koji in the usual way. The saccharification power of the new koji was about 1.1 to 1.2 times as strong as that of usual koji prepared from wheat bran and rice husks.

Batch fermentative production of lactic acid from green- sugarcane juices

Directory of Open Access Journals (Sweden)

Liliana Serna Cock

2004-07-01

Full Text Available Juice from the CC85-92 variety of green (unburned sugar cane was tested as a suitable substrate in lactic-acid production. Fermentations were carried out with a homo-fermentative strain isolated from crops of the same variety of cane. Both the centrifugation pre-treatment and concentrated-nitrogen effects on substrate conversion, lactic-acid concentration and yield were evaluated. After a fermentation time of 48 h at 32° C with 5% of yeast extract as nitrogen source, 40,78 g/L of lactic-acid concentration, 0.58 g/g of product yield and 33% of substrate conversion were obtained. Centrifugation did not affect lactic acid production. Key words: Lactic acid, green sugar cane, Lactococcus lactis subs. lactis.

Multi-stage Continuous Culture Fermentation of Glucose-Xylose Mixtures to Fuel Ethanol using Genetically Engineered Saccharomyces cerevisiae 424A

Science.gov (United States)

Multi-stage continuous (chemostat) culture fermentation (MCCF) with variable fermentor volumes was carried out to study utilizing glucose and xylose for ethanol production by means of mixed sugar fermentation (MSF). Variable fermentor volumes were used to enable enhanced sugar u...

IRREVERSIBILITY GENERATION IN SUGAR, ALCOHOL AND BIOGAS INTEGRATED PRODUCTIONS

Directory of Open Access Journals (Sweden)

Meilyn González Cortés

2017-01-01

Full Text Available In this work, the stages of losses and lower exergetic efficiency are determined when the sugar production process is integrated with others for the production of products such as biogas, torula yeast and electricity. The study is carried out in three scenarios of integrated processes for obtaining the indicated products. A sugar factory in which sugar and electricity are produced is considered as the base scenario and from this; a second scenario is inferred in which alcohol is produced from the molasses of the sugar process and biogas from the vinasse of the alcohol distillation process. Finally, a third scenario is exergetically evaluated in which sugar, electricity, biogas and alcohol are produced, but this last one from juices and molasses of the sugar process. For the exergetic analysis the integrated scheme was divided into 8 subsystems. From the analysis of results, the major subsystems that generate irreversibilities are: cogeneration (64.36-65.98%, juice extraction (8.85-9.85%, crystallization and cooking, (8.48 -9.02%, fermentation (4.12-4.94% and distillation (2.74-3.2%. Improvements are proposed to minimize irreversibilities, including the thermal integration of processes, technological modifications in the fermentation process and the introduction of more efficient equipment for the generation of electricity. The exergetic efficiency is between 78.95-81.10%, obtaining greater exergetic efficiency in the scheme of joint operation to produce sugar, alcohol and biogas.

Improving bioavailability of fruit wastes using organic acid: An exploratory study of biomass pretreatment for fermentation

International Nuclear Information System (INIS)

Saha, Shouvik; Kurade, Mayur B.; El-Dalatony, Marwa M.; Chatterjee, Pradip K.; Lee, Dae Sung; Jeon, Byong-Hun

2016-01-01

Highlights: • Maximum sugar recovery was achieved with 100 °C/1 h treatment in 0.2 M acetic acid. • C/N ratios (41–47) were retained in all FPWs after the acetic acid treatment. • Combined severity (−0.83) of acetic acid enhanced the bioavailability of the FPWs. • Acetic acid pretreatment is advantageous over mineral acid to curtail sugar loss. • Estimated methane yields are promising for the industrial feasibility. - Abstract: Maximizing the bioavailability of fermentable biomass components is a key challenge in biomass pretreatment due to the loss of sugars during conventional pretreatment approaches. Pretreatment of fruit peels and wastes (FPWs) with dilute acetic acid assisted in maximizing sugar recovery. Optimized conditions (0.2 M acetic acid, 100 °C, 1 h) at 10% substrate loading resulted in enhanced sugar recovery from banana peels (99.9%), pineapple wastes (99.1%), grape pomace (98.8%), and orange peels (97.9%). These high sugar recoveries retained the high C/N ratios (41–47) suitable for effective bioenergy production through the fermentation of these pretreated biomasses. Scanning electron microscopy (SEM) indicated considerable disruption of biomass structural integrity during acetic acid treatment, enhancing the surface area available for better microbial attachment. Fourier transform infrared spectroscopy (FTIR) showed that the acetic acid pretreatment yielded only minor changes to the functional groups in the biomasses, strongly suggesting minimal loss of fermentable sugars. Thus, acetic acid pretreatment aids in enhancing the bioavailability of fermentable sugars from these FPWs biomass, enabling improvements in bioenergy production.

Synergistic effect of pretreatment and fermentation process on carbohydrate-rich Scenedesmus dimorphus for bioethanol production

International Nuclear Information System (INIS)

Chng, Lee Muei; Lee, Keat Teong; Chan, Derek Juinn Chieh

2017-01-01

Highlights: • Biomass of Scenedesmus dimorphus is degradable to produce fermentable sugar. • Sugar yield improves with acidic, enzymatic and organosolv pretreatment. • Pretreatment strategies are positively correlated with fermentation process. • SSF with organosolv-treated biomass is promising for bioethanol production. - Abstract: Significant development in conversion technologies to produce bioethanol from microalgae biomass is causing paradigm-shift in energy management. In this study, carbohydrate-rich microalgae, Scenedesmus dimorphus (49% w/w of carbohydrate) is selected with the aim to obtain qualitative correlation between pretreatment and fermentation process. In view of this, separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) were conducted experimentally. The fermentation behavior were investigated for microalgae biomass treated via organosolv, enzymatic and acidic pretreatment. Fermentation process was carried out by ethanologen microbe, Saccharomyces cerevisiae. From the result, it is observed that a combination of two treatment is found to be the most effective in producing fermentable sugar for the subsequent fermentation process. The organosolv treatment which is followed with the SSF process produced a theoretical yield of bioethanol that exceeded 90%. On the other hand, hydrothermal acid-hydrolyzed fermentation produced the bioethanol yield with 80% of its theoretical yield. Enzymatic-hydrolyzed SHF produced 84% of theoretical yield at longer reaction time compared with others. The results were obtained with constant fermentation parameters conducted at pH 5, temperature of 34 °C, and microalgae biomass loading at 18 g/L. Ultimately, the coupling of organosolv-treated biomass with SSF process is found to be the most cost-effective for S. dimorphus biomass as bioethanol feedstock.

Lignases and aldo-keto reductases for conversion of lignin-containing materials to fermentable products

Science.gov (United States)

Scharf, Michael; Sethi, Amit

2016-09-13

Termites have specialized digestive systems that overcome the lignin barrier in wood to release fermentable simple sugars. Using the termite Reticulitermes flavipes and its gut symbionts, high-throughput titanium pyrosequencing and proteomics approaches experimentally compared the effects of lignin-containing diets on host-symbiont digestome composition. Proteomic investigations and functional digestive studies with recombinant lignocellulases conducted in parallel provided strong evidence of congruence at the transcription and translational levels and provide enzymatic strategies for overcoming recalcitrant lignin barriers in biofuel feedstocks. Briefly described, therefore, the disclosure provides a system for generating a fermentable product from a lignified plant material, the system comprising a cooperating series of at least two catalytically active polypeptides, where said catalytically active polypeptides are selected from the group consisting of: cellulase Cell-1, .beta.-glu cellulase, an aldo-keto-reductase, a catalase, a laccase, and an endo-xylanase.

Effects of pretreatment methods for hazelnut shell hydrolysate fermentation with Pichia Stipitis to ethanol.

Science.gov (United States)

Arslan, Yeşim; Eken-Saraçoğlu, Nurdan

2010-11-01

In this study, we investigated the use of hazelnut shell as a renewable and low cost lignocellulosic material for bioethanol production for the first time. High lignin content of hazelnut shell is an important obstacle for such a biotransformation. Biomass hydrolysis with acids yields reducing sugar with several inhibitors which limit the fermentability of sugars. The various conditioning methods for biomass and hydrolysate were performed to overcome the toxicity and their effects on the subsequent fermentation of hazelnut shell hydrolysate by Pichia stipitis were evaluated with shaking flasks experiments. Hazelnut shells hydrolysis with 0.7M H(2)SO(4) yielded 49 gl(-1) total reducing sugars and fermentation inhibitors in untreated hydrolysate. First, it was shown that several hydrolysate detoxification methods were solely inefficient in achieving cell growth and ethanol production in the fermentation of hazelnut shell hydrolysates derived from non-delignified biomass. Next, different pretreatments of hazelnut shells were considered for delignification and employed before hydrolysis in conjunction with hydrolysate detoxification to improve alcohol fermentation. Among six delignification methods, the most effective pretreatment regarding to ethanol concentration includes the treatment of shells with 3% (w/v) NaOH at room temperature, which was integrated with sequential hydrolysate detoxification by overliming and then treatment with charcoal twice at 60 degrees C. This treatment brought about a total reduction of 97% in furans and 88.4% in phenolics. Almost all trialed treatments caused significant sugar loss. Under the best assayed conditions, ethanol concentration of 16.79gl(-1) was reached from a hazelnut shell hyrolysate containing initial 50g total reducing sugar l(-1) after partial synthetic xylose supplementation. This value is equal to 91.25% of ethanol concentration that was obtained from synthetic d-xylose under same conditions. The present study

Working-up of sugar beets and defective wheat

Energy Technology Data Exchange (ETDEWEB)

Tokmakova, M M

1959-01-01

Sugar beets can be prepared for fermentation to EtOH by treating them with boiling H/sub 2/O at 4 atmosphere pressure for 30 minutes. If defective wheat (such as wheat attacked by frost) is added to such beets, time must be increased to 1 hour. During the fermentation the temperature of the liquor obtained is maintained at 23 to 24/sup 0/, it will not foam.

Fermentation of starches and sugars to alcohol

Energy Technology Data Exchange (ETDEWEB)

Fertman, G I; Berenshtein, A F; Gulyaev, J P

1958-02-25

To prevent the growth of acid-forming bacteria in the started wort, the ester-aldehyde fraction or the amino alcohol obtained in the rectification process is returned to the wort in amounts sufficient to give an alcohol concentration of approximately 1.5% by volume. The fermenting wort is also acidified to 0.5 to 0.6.

The contribution of autochthonous microflora on free fatty acids release and flavor development in low-salt fermented fish.

Science.gov (United States)

Xu, Yanshun; Li, Lin; Regenstein, Joe Mac; Gao, Pei; Zang, Jinhong; Xia, Wenshui; Jiang, Qixing

2018-08-01

To investigate the contribution of autochthonous microflora on free fatty acids (FFA) release and flavor development in low-salt fermented fish, three groups of processed fish, including bacteriostatic-acidification group (BAG), bacteriostatic group (BG), and spontaneous fermented fish (CG) were established. Results showed that addition of NaN 3 reduced microbial load in BAG and BG below 3.5 log CFU/g after 3 weeks of incubation. Activities of lipases and lipoxygenase declined markedly with increasing time, where BG had the highest activities, followed by CG and BAG. There is a 36.3% higher in the total FFA content in CG than that in BAG, indicating both microbial and endogenous lipases contributed to the FFA liberation in fermented fish while endogenous lipases play a major role. However, compared to BAG and BG, largely higher levels of volatile compounds were observed in CG, suggesting that autochthonous microflora dominated the generation of volatile flavor compounds in fermented fish. Copyright © 2018 Elsevier Ltd. All rights reserved.

EVALUATION OF FERMENTATION PARAMETERS DURING HIGH-GRAVITY BEER PRODUCTION

Directory of Open Access Journals (Sweden)

R.B. Almeida

2001-12-01

Full Text Available A large number of advantages are obtained from the use of highly concentrated worts during the production of beer in a process referred to as "high-gravity". However, problems related to slow or stuck fermentations, which cause the lower productivity and possibility of contamination, are encountered. This study examines the influence of factors pH, percentage of corn syrup, initial wort concentration and fermentation temperature on the fermentation parameters, namely productivity, wort attenuation and the yield coefficient for sugar-to-ethanol conversion. The results show that productivity increased when the higher temperature, the higher wort concentration and the lower syrup percentage were used, while wort attenuation increased when lower wort concentration and no syrup were used. The yield coefficient for sugar-to-ethanol conversion was not influenced by any of the factors studied.

Incorporation of whey permeate, a dairy effluent, in ethanol fermentation to provide a zero waste solution for the dairy industry.

Science.gov (United States)

Parashar, Archana; Jin, Yiqiong; Mason, Beth; Chae, Michael; Bressler, David C

2016-03-01

This study proposes a novel alternative for utilization of whey permeate, a by-product stream from the dairy industry, in wheat fermentation for ethanol production using Saccharomyces cerevisiae. Whey permeates were hydrolyzed using enzymes to release fermentable sugars. Hydrolyzed whey permeates were integrated into wheat fermentation as a co-substrate or to partially replace process water. Cold starch hydrolysis-based simultaneous saccharification and fermentation was done as per the current industrial protocol for commercial wheat-to-ethanol production. Ethanol production was not affected; ethanol yield efficiency did not change when up to 10% of process water was replaced. Lactic acid bacteria in whey permeate did not negatively affect the co-fermentation or reduce ethanol yield. Whey permeate could be effectively stored for up to 4 wk at 4 °C with little change in lactose and lactic acid content. Considering the global abundance and nutrient value of whey permeate, the proposed strategy could improve economics of the dairy and biofuel sectors, and reduce environmental pollution. Furthermore, our research may be applied to fermentation strategies designed to produce value-added products other than ethanol. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Food Grade Ehanol Production With Fermentation And Distillation Process Using Stem Sorghum

Directory of Open Access Journals (Sweden)

Yuliana Setyowati

2015-03-01

Full Text Available 10% -12% of sugar in its stem which is the optimum sugar concentration in fermentation process for bioethanol production. Sorghum has a high potential to be developed as a raw material for food-grade ethanol production which can be used to support food-grade ethanol demand in Indonesia through a fermentation process. This research focused on the effect of microorganism varieties in the fermentation process which are mutant Zymomonas mobilis (A3, Saccharomyces cerevisiae and Pichia stipitis mixture. The Research for purification process are separated into two parts, distillation with steel wool structured packing and dehydration process using molecular sieve and eliminating impurities using activated carbon. The research can be concluded that the best productivity shown in continuous fermentation in the amount of 84.049 (g / L.hr using the mixture of Saccharomyces cerevisiae and Pichia stipitis. The highest percentage of ethanol yield produced in batch fermentation using the mixture of Saccharomyces cerevisiae and Pichia stipitis that is equal to 51.269%. And for the adsorption, the best result shown in continuous fermentation by using Zymomonas Mobilis of 88.374%..

Effect of Varying Acid Hydrolysis Condition in Gracilaria Sp. Fermentation Using Sasad

Science.gov (United States)

Mansuit, H.; Samsuri, M. D. C.; Sipaut, C. S.; Yee, C. F.; Yasir, S. M.; Mansa, R.

2015-04-01

Macroalgae or seaweed is being considered as promising feedstock for bioalcohol production due to high polysaccharides content. Polysaccharides can be converted into fermentable sugar through acid hydrolysis pre-treatment. In this study, the potential of using carbohydrate-rich macroalgae, Gracilaria sp. as feedstock for bioalcohol production via various acid hydrolysis conditions prior to the fermentation process was investigated and evaluated. The seaweed used in this research was from the red algae group, using species of Gracilaria sp. which was collected from Sg. Petani Kedah, Malaysia. Pre-treatment of substrate was done using H2SO4 and HCl with molarity ranging from 0.2M to 0.8M. The pretreatment time were varied in the range of 15 to 30 minutes. Fermentation was conducted using Sasad, a local Sabahan fermentation agent as a starter culture. Alcohol extraction was done using a distillation unit. Reducing sugar analysis was done by Benedict test method. Alcohol content analysis was done using specific gravity test. After hydrolysis, it was found out that acid hydrolysis at 0.2M H2SO4 and pre-treated for 20 minutes at 121°C has shown the highest reducing sugar content which has yield (10.06 mg/g) of reducing sugar. It was followed by other samples hydrolysis using 0.4M HCl with 30 minutes pre-treatment and 0.2M H2SO4, 15 minutes pre-treatment with yield of 8.06 mg/g and 5.75 mg/g reducing sugar content respectively. In conclusion, acid hydrolysis of Gracilaria sp. can produce higher reducing sugar yield and thus it can further enhance the bioalcohol production yield. Hence, acid hydrolysis of Gracilaria sp. should be studied more as it is an important step in the bioalcohol production and upscaling process.

Application of butyl alcohol bacteria for the fermentation of nonnutritive raw materials

Energy Technology Data Exchange (ETDEWEB)

Nakhamanovich, B M; Senkevich, V V; Yarovenko, V L

1961-01-01

Materials like corncobs after hydrolysis can be economically fermented by using bacteria which support a butyl alcohol-acetone fermentation. Best results are obtained if (NH/sub 4/)/sub 2/SO/sub 4/ and superphosphate are added to the fermentation liquor. Analyses are presnted of the hydrolzates (alcohols, formic acid, 2-furaldehyde, and reducing sugars) and of the final products.

Ultrafiltration of hemicellulose hydrolysate fermentation broth

Science.gov (United States)

Kresnowati, M. T. A. P.; Desiriani, Ria; Wenten, I. G.

2017-03-01

Hemicelulosic material is often used as the main substrate to obtain high-value products such as xylose. The five carbon sugar, xylose, could be further processed by fermentation to produce xylitol. However, not only the hemicellulose hydrolysate fermentation broth contains xylitol, but also metabolite products, residual substances, biomass and mineral salts. Therefore, in order to obtain the end products, various separation processes are required to separate and purify the desired product from the fermentation broth. One of the most promising downstream processing methods of fermentation broth clarification is ultrafiltration due to its potential for energy saving and higher purity. In addition, ultrafiltration membrane has a high performance in separating inhibitory components in the fermentation broth. This paper assesses the influence of operating conditions; including trans-membrane pressure, velocity, pH of the fermentation broth solutions, and also to the xylitol concentration in the product. The challenges of the ultrafiltration process will be pointed out.

Fermentation of Prefermented and Extruded Rice Flour by Lactic Acid Bacteria from Sikhae

DEFF Research Database (Denmark)

Lee, C. H.; Min, K. C.; Souane, M.

1992-01-01

of prefermentation of rice flour in solid-state with Bacillus laevolacticus and Saccharomyces cerevisiae, extrusion cooking and addition of soymilk as the substrate of lactic acid fermentation were tested. Extrusion cooking and prefermentation of rice increased the soluble solid and sugar contents before malt......The acid- and flavor-forming properties of Lactobacillus plantarum and Leuconostoc mesenteroides isolated from Sikhae, a Korean traditional lactic acid fermented fish product, were examined and compared to those of Lactobacillus casei and Lactococcus lactis subsp. diacetylactis DRC3. The effects...... digestion. The amount of sugar consumption during lactic fermentation varied with the type of bacteria. Leuconostoc mesenteroides(sikhae) and Lactobacillus plantarum(sikhae) increased up to 6 times of original cell number by 24 hrs of fermentation in rice + soymilk substrate, but Lactococcus lactis...

Kinetic modeling and dynamic analysis of simultaneous saccharification and fermentation of cellulose to bioethanol

International Nuclear Information System (INIS)

Shadbahr, Jalil; Khan, Faisal; Zhang, Yan

2017-01-01

Highlights: • Deeper understanding of saccharification and fermentation process. • A new kinetic model for dynamic analysis of the simultaneous saccharification and fermentation. • Testing and validation of kinetic model. - Abstract: Kinetic modeling and dynamic analysis of the simultaneous saccharification and fermentation (SSF) of cellulose to ethanol was carried out in this study to determine the key reaction kinetics parameters and product inhibition features of the process. To obtain the more reliable kinetic parameters which can be applied for a wide range of operating conditions, batch SSF experiments were carried out at three enzyme loadings (10, 15 and 20 FPU/g cellulose) and two levels of initial concentrations of fermentable sugars (glucose and mannose). Results indicated that the maximum ethanol yield and concentration were achieved at high level of sugar concentrations with intermediate enzyme loading (15 FPU/g cellulose). Dynamic analysis of the acquired experimental results revealed that cellulase inhibition by cellobiose plays the most important role at high level of enzyme loading and low level of initial sugar concentrations. The inhibition of glucose becomes significant when high concentrations of sugars were present in the feedstock. Experimental results of SSF process also reveal that an efficient mixing between the phases helps to improve the ethanol yield significantly.

Sugar Release and Growth of Biofuel Crops are Improved by Downregulation of Pectin Biosynthesis

Energy Technology Data Exchange (ETDEWEB)

Donohoe, Bryon S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sykes, Robert W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gjersing, Erica L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ziebell, Angela [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Turner, Geoffrey [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Decker, Steve [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Davis, Mark F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Biswal, Ajaya K. [University of Georgia; Oak Ridge National Laboratory; Atmodjo, Melani A. [University of Georgia; Oak Ridge National Laboratory; Li, Mi [Oak Ridge National Laboratory; UT-ORNL Joint Institute for Biological Sciences; Baxter, Holly L. [Oak Ridge National Laboratory; University of Tennessee; Yoo, Chang Geun [Oak Ridge National Laboratory; UT-ORNL Joint Institute for Biological Sciences; Pu, Yunqiao [Oak Ridge National Laboratory; UT-ORNL Joint Institute for Biological Sciences; Lee, Yi-Ching [Oak Ridge National Laboratory; Noble Research Institute; Mazarei, Mitra [Oak Ridge National Laboratory; University of Tennessee; Black, Ian M. [University of Georgia; Zhang, Ji-Yi [Oak Ridge National Laboratory; Noble Research Institute; Ramanna, Hema [Oak Ridge National Laboratory; Noble Research Institute; Bray, Adam L. [Oak Ridge National Laboratory; University of Georgia; King, Zachary R. [Oak Ridge National Laboratory; University of Georgia; LaFayette, Peter R. [Oak Ridge National Laboratory; University of Georgia; Pattathil, Sivakumar [University of Georgia; Oak Ridge National Laboratory; Mohanty, Sushree S. [University of Georgia; Oak Ridge National Laboratory; Ryno, David [University of Georgia; Oak Ridge National Laboratory; Yee, Kelsey [Oak Ridge National Laboratory; Thompson, Olivia A. [Oak Ridge National Laboratory; Rodriguez Jr., Miguel [Oak Ridge National Laboratory; Dumitrache, Alexandru [Oak Ridge National Laboratory; Natzke, Jace [Oak Ridge National Laboratory; Winkeler, Kim [Oak Ridge National Laboratory; ArborGen, Inc.; Collins, Cassandra [Oak Ridge National Laboratory; ArborGen, Inc.; Yang, Xiaohan [Oak Ridge National Laboratory; Tan, Li [University of Georgia; Oak Ridge National Laboratory; Hahn, Michael G. [University of Georgia; Oak Ridge National Laboratory; Davison, Brian H. [Oak Ridge National Laboratory; Udvardi, Michael K. [Oak Ridge National Laboratory; Noble Research Institute; Mielenz, Jonathan R. [Oak Ridge National Laboratory; Nelson, Richard S. [Oak Ridge National Laboratory; Noble Research Institute; Parrott, Wayne A. [Oak Ridge National Laboratory; University of Georgia; Ragauskas, Arthur J. [Oak Ridge National Laboratory; UT-ORNL Joint Institute for Biological Sciences; University of Tennessee; Stewart Jr., C. Neal [Oak Ridge National Laboratory; University of Tennessee; Mohnen, Debra [University of Georgia; Oak Ridge National Laboratory

2018-02-12

Cell walls in crops and trees have been engineered for production of biofuels and commodity chemicals, but engineered varieties often fail multi-year field trials and are not commercialized. We engineered reduced expression of a pectin biosynthesis gene (Galacturonosyltransferase 4, GAUT4) in switchgrass and poplar, and find that this improves biomass yields and sugar release from biomass processing. Both traits were maintained in a 3-year field trial of GAUT4-knockdown switchgrass, with up to sevenfold increased saccharification and ethanol production and sixfold increased biomass yield compared with control plants. We show that GAUT4 is an a-1,4-galacturonosyltransferase that synthesizes homogalacturonan (HG). Downregulation of GAUT4 reduces HG and rhamnogalacturonan II (RGII), reduces wall calcium and boron, and increases extractability of cell wall sugars. Decreased recalcitrance in biomass processing and increased growth are likely due to reduced HG and RGII cross-linking in the cell wall.

Composition of sugar cane, energy cane, and sweet sorghum suitable for ethanol production at Louisiana sugar mills.

Science.gov (United States)

Kim, Misook; Day, Donal F

2011-07-01

A challenge facing the biofuel industry is to develop an economically viable and sustainable biorefinery. The existing potential biorefineries in Louisiana, raw sugar mills, operate only 3 months of the year. For year-round operation, they must adopt other feedstocks, besides sugar cane, as supplemental feedstocks. Energy cane and sweet sorghum have different harvest times, but can be processed for bio-ethanol using the same equipment. Juice of energy cane contains 9.8% fermentable sugars and that of sweet sorghum, 11.8%. Chemical composition of sugar cane bagasse was determined to be 42% cellulose, 25% hemicellulose, and 20% lignin, and that of energy cane was 43% cellulose, 24% hemicellulose, and 22% lignin. Sweet sorghum was 45% cellulose, 27% hemicellulose, and 21% lignin. Theoretical ethanol yields would be 3,609 kg per ha from sugar cane, 12,938 kg per ha from energy cane, and 5,804 kg per ha from sweet sorghum.

Alcohol for cellulosic material using plural ferments

Energy Technology Data Exchange (ETDEWEB)

Hoge, W H

1977-02-22

A process is described for producing ethanol (EtOH) from cellulosic materials by first hydrolyzing the material to sugars and then converting the sugars to alcohol by digestion and fermentation. Thus, fibrous cellulosic material obtained from municipal waste slurry was sterilized by autoclaving, followed by inoculation with Trichoderma viride cellulase and Saccharomyces cerevisiae. From 100 g of raw material, 25 mL of 95% EtOH was produced by this method.

The economics of sugar beets in biogas production; Vergaerung von Zuckerrueben in Biogasanlagen. Lohnt sich das?

Energy Technology Data Exchange (ETDEWEB)

Hartmann, Stefan; Doehler, Helmut [Kuratorium fuer Technik und Bauwesen in der Landwirtschaft e.V. (KTBL), Darmstadt (Germany)

2011-07-01

The economics of employing sugar beets for biogas production were investigated using a calculation model based on the currently available data. Taken into account were all steps of the chain from cultivation, conditioning and conservation to the influences in the biogas plant. Only by calculating with very good assumptions for the fermentation of sugar beets, they can constitute an economical alternative to the use of silo maize as a fermentation substrate. (orig.)

Technology and economics of fermentation alcohol - an update

Energy Technology Data Exchange (ETDEWEB)

Carroll, R.K.

1983-03-01

Fermentation alcohol is being widely studied as an alternative fuel, and production is increasing, especially in Brazil, where the goal is more than 10 billion litres per year by 1985. Fuel markets are hundreds of times greater than the traditional ethanol markets which the existing industry supplies. To make a material contribution to fuel supply, fermentation ethanol must be treated as a major chemical and produced in large-volume, highly efficient plants. Such plants must be assured of a continuous supply of low-cost raw materials for which suitable processes have been developed and commercially proven. Sugar cane in the tropics and grains in some temperate countries meet these requirements; cellulosics do not qualify at present, nor will they in the foreseeable future, without major breakthroughs. Using techniques borrowed from the starch sweetener industry, starchy materials may be economically hydrolysed to fermentable sugars; rapid acid hydrolysis may prove superior to enzymatic processes. Major projects are under way to replace traditional batch or cascade fermentations with rapid, single-vessel continuous units, but these have not yet been fully proven. Where suitable, yeast recycle is being used as a means of increasing alcohol yields, and energy-efficient distillation methods of the petrochemical industry are being adopted. The consequent large reduction in steam consumption greatly reduces the appeal of other methods which have been proposed to remove water. Opportunities for process improvements abound, especially in developing (1) the means to provide cellulosic raw materials in large quantities at acceptable costs, (2) economically effective methods of pretreating and hydrolysing cellulosics, (3) practical organisms for converting five-carbon sugars to ethanol and (4) higher fermentation yields and efficiencies using bacteria or immobilized yeast. (Refs. 21).

Effect of high-sugar grasses on methane emissions simulated using a dynamic model

NARCIS (Netherlands)

St-Pierre, J.L.; Dijkstra, J.; France, J.; Parsons, A.J.; Edwards, G.R.; Rasmussen, S.; Kebreab, E.; Bannink, A.

2012-01-01

High-sugar grass varieties have received considerable attention for their potential ability to decrease N excretion in cattle. However, feeding high-sugar grasses alters the pattern of rumen fermentation, and no in vivo studies to date have examined this strategy with respect to another

Decomposition and hydrolysis of starch-containing raw materials and their fermentation to alcohol

Energy Technology Data Exchange (ETDEWEB)

Rolf, D D

1957-08-29

A mixture of 1000kg bruised mash (60.5% starch) and 2600 kg 0.1% H/sub 2/SO/sub 4/ was heated for 4 minutes to 180/sup 0/. After cooling to 60/sup 0/ it was neutralized by lime to pH 5.2 sugared with 50g kiln-dried malt, and then fermented for 48 hours. Alternatively, the mixture was heated to 180/sup 0/, sugared with 100 kg kiln-dried malt, and then fermented for 66 hours.

Performance study of sugar-yeast-ethanol bio-hybrid fuel cells

Science.gov (United States)

Jahnke, Justin P.; Mackie, David M.; Benyamin, Marcus; Ganguli, Rahul; Sumner, James J.

2015-05-01

Renewable alternatives to fossil hydrocarbons for energy generation are of general interest for a variety of political, economic, environmental, and practical reasons. In particular, energy from biomass has many advantages, including safety, sustainability, and the ability to be scavenged from native ecosystems or from waste streams. Microbial fuel cells (MFCs) can take advantage of microorganism metabolism to efficiently use sugar and other biomolecules as fuel, but are limited by low power densities. In contrast, direct alcohol fuel cells (DAFCs) take advantage of proton exchange membranes (PEMs) to generate electricity from alcohols at much higher power densities. Here, we investigate a novel bio-hybrid fuel cell design prepared using commercial off-the-shelf DAFCs. In the bio-hybrid fuel cells, biomass such as sugar is fermented by yeast to ethanol, which can be used to fuel a DAFC. A separation membrane between the fermentation and the DAFC is used to purify the fermentate while avoiding any parasitic power losses. However, shifting the DAFCs from pure alcohol-water solutions to filtered fermented media introduces complications related to how the starting materials, fermentation byproducts, and DAFC waste products affect both the fermentation and the long-term DAFC performance. This study examines the impact of separation membrane pore size, fermentation/fuel cell byproducts, alcohol and salt concentrations, and load resistance on fuel cell performance. Under optimized conditions, the performance obtained is comparable to that of a similar DAFC run with a pure alcohol-water mixture. Additionally, the modified DAFC can provide useable amounts of power for weeks.

Accounting for all sugars produced during integrated production of ethanol from lignocellulosic biomass.

Science.gov (United States)

Schell, Daniel J; Dowe, Nancy; Chapeaux, Alexandre; Nelson, Robert S; Jennings, Edward W

2016-04-01

Accurate mass balance and conversion data from integrated operation is needed to fully elucidate the economics of biofuel production processes. This study explored integrated conversion of corn stover to ethanol and highlights techniques for accurate yield calculations. Acid pretreated corn stover (PCS) produced in a pilot-scale reactor was enzymatically hydrolyzed and the resulting sugars were fermented to ethanol by the glucose-xylose fermenting bacteria, Zymomonas mobilis 8b. The calculations presented here account for high solids operation and oligomeric sugars produced during pretreatment, enzymatic hydrolysis, and fermentation, which, if not accounted for, leads to overestimating ethanol yields. The calculations are illustrated for enzymatic hydrolysis and fermentation of PCS at 17.5% and 20.0% total solids achieving 80.1% and 77.9% conversion of cellulose and xylan to ethanol and ethanol titers of 63g/L and 69g/L, respectively. These procedures will be employed in the future and the resulting information used for techno-economic analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Monitoring of metabolites and by-products in a down-scaled industrial lager beer fermentation

OpenAIRE

Sjöström, Fredrik

2013-01-01

The sugar composition of the wort and how these sugars are utilised by the yeast affects the organoleptic properties of the beer. To monitor the saccharides in the wort before inoculation and during fermentation is important in modern brewing industry. Reducing the duration of the brewing process is valuable and can be achieved by reducing the fermentation time by an increase in temperature. However, this must be done without changing the quality and characteristics of the end product, anothe...

Biochemical changes in low-salt solid-state fermented soy sauce ...

African Journals Online (AJOL)

Results showed that after a 15-day aging period, the contents of total nitrogen, formol titration nitrogen, free amino acids, reducing sugar, total sugar and the brown color were increased. However, pH was decreased during the fermentation period. Furthermore, contents of total free amino acids in low-salt solid-state ...

Liberation of fermentable sugars from soybean hull biomass using ionic liquid 1-butyl-3-methylimidazolium acetate and their bioconversion to ethanol.

Science.gov (United States)

da Cunha-Pereira, Fernanda; Rech, Rosane; Záchia Ayub, Marco Antônio; Pinheiro Dillon, Aldo; Dupont, Jairton

2016-03-01

Optimized hydrolysis of lignocellulosic waste biomass is essential to achieve the liberation of sugars to be used in fermentation process. Ionic liquids (ILs), a new class of solvents, have been tested in the pretreatment of cellulosic materials to improve the subsequent enzymatic hydrolysis of the biomass. Optimized application of ILs on biomass is important to advance the use of this technology. In this research, we investigated the effects of using 1-butyl-3-methylimidazolium acetate ([bmim][Ac]) on the decomposition of soybean hull, an abundant cellulosic industrial waste. Reaction aspects of temperature, incubation time, IL concentration, and solid load were optimized before carrying out the enzymatic hydrolysis of this residue to liberate fermentable glucose. Optimal conditions were found to be 75°C, 165 min incubation time, 57% (mass fraction) of [bmim][Ac], and 12.5% solid loading. Pretreated soybean hull lost its crystallinity, which eased enzymatic hydrolysis, confirmed by Fourier Transform Infrared analysis. The enzymatic hydrolysis of the biomass using an enzyme complex from Penicillium echinulatum liberated 92% of glucose from the cellulose matrix. The hydrolysate was free of any toxic compounds, such as hydroxymethylfurfural and furfural. The obtained hydrolysate was tested for fermentation using Candida shehatae HM 52.2, which was able to convert glucose to ethanol at yields of 0.31. These results suggest the possible use of ILs for the pretreatment of some lignocellulosic waste materials, avoiding the formation of toxic compounds, to be used in second-generation ethanol production and other fermentation processes. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:312-320, 2016. © 2015 American Institute of Chemical Engineers.

Comparative behaviour of yeast strains for ethanolic fermentation of culled apple juice.

Science.gov (United States)

Modi, D R; Garg, S K; Johri, B N

1998-07-01

The culled apple juice contained (% w/v): nitrogen, 0.036; total sugars, 11.6 and was of pH 3.9. Saccharomyces cerevisiae NCIM 3284, Pichia kluyeri and Candida krusei produced more ethanol from culled apple juice at its optimum initial pH 4.5, whereas S. cerevisiae NCIM 3316 did so at pH 5.0. An increase in sugar concentration of apple juice from natural 11.6% to 20% exhibited enhanced ethanol production and improved fermentation efficiency of both the S. cerevisiae strains, whereas P. kluyveri and C. krusei produced high ethanol at 11.6% and 16.0% sugar levels, respectively. Urea was stimulatory for ethanol production as well as fermentation efficiency of the yeast strains under study.

The role of Staphylococcus species in the production of iru during the fermentation of African locust beans (Parkia biglobosa

Directory of Open Access Journals (Sweden)

Amao, J.A.

2017-12-01

Full Text Available Staphylococcus spp. are regularly isolated from iru, but the role(s they play in the fermentation process has not yet been determined; this work thus seeks to determine if Staphylococcus spp. isolated from iru play any role in the fermentation of African locust bean. Bacillus spp. and Staphylococcus spp. isolated from spontaneously fermented African locust bean (iru were used to ferment African locust beans. The temperature, pH and moisture content were determined as fermentation progress while the total soluble sugar and total free amino acid were determined after fermentation. The microbial load for the three iru products increased gradually until the end of fermentation. The total free amino acids increased in all three iru (1.10, 1.51 and 2.35 mg leucine ml-1 for Staphylococcus spp. iru, Bacillus spp. iru and iru produced with combination of the two species of bacteria when compared with that of the unfermented bean, while the total soluble sugars reduced after fermentation with Staphylococcus spp. iru having 3.84, Bacillus spp. iru has 3.60, and the unfermented bean has 5.30 mg glucose ml-1 total soluble sugar. The increased free amino acids in the iru fermented with Staphylococcus spp. and the ability of the Staphylococcus spp. to produce lipase showed that Staphylococcus spp. isolated from iru has the ability to ferment African locust bean and carry out the lipolytic activity during the fermentation.

Continuous saccharification and fermentation in alcohol production

Energy Technology Data Exchange (ETDEWEB)

Veselov, I Ya; Gracheva, I M; Mikhailova, L E; Babaeva, S A; Ustinnikov, B A

1968-01-01

Submerged cultures of Aspergillus niger NRRL 337 and A. batatae 61, or a mixture of submerged A. niger culture with a surface culture of A. oryzae Kc are used for fermentations and compared with the usual barley malt procedure. The latter yields 71% maltose and 24 to 28% glucose, wherease the fungal procedure gives 14 to 21% maltose and 80 to 85% glucose in a continuous mashing-fermentation process with barley. The fungal method gives a higher degree of fermentation for sugars and dextrins and a lower content of total and high-molecular-weight residual dextrins. The amounts of propanol PrOH and iso-BuOH isobutyl alcohol are almost equal, whereas the amount of isoamylalcohol is lower in fungal fermentations.

Factors associated with the acceptance of sugar and sugar substitutes by the public.

Science.gov (United States)

Mackay, D A

1985-09-01

Acceptance is described in both market and sensory research terminology and recent developments in the fields of applied psychology and physiology are examined for their pertinence to public acceptance of sucrose and its substitutes. Information on the function of sucrose in foods other than beverages is presented with emphasis on salivation as an acceptance factor and attention is drawn to its possible dental significance. Distinctions are made between the sweetening and bulking properties of sucrose and sugar substitutes. Factors having a bearing on the acceptance of sweet foods and the determination of their optimal sugar content are described in detail. While major decreases in sucrose intake in the US resulted from high-fructose corn-sweetener usage in soft drinks, no evidence is yet available to suggest that the use of sugar substitutes of the intense artificial sweetener type has caused any decrease in ordinary sugar consumption. Neither is the consumption of polyols (sorbitol, mannitol, xylitol) high enough in confectionery categories to cause any discernible decrease in sugar usage. The evidence suggests not so much that sugar substitutes may have stopped the growth in sucrose usage, but that new product categories such as diet foods and "sugarless' confections may have been created. These categories were never available to fermentable carbohydrate sweeteners and equivalence in acceptance to sucrose-sweetened products was not an important factor in their growth.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

KOMBUCHA DENGAN VARIASI KADAR GULA KELAPA SEBAGAI SUMBER KARBON [Kombucha from Different Coconut Sugar Concentration as a Carbon Source

Directory of Open Access Journals (Sweden)

Merkuria Karyantina

2008-12-01

Full Text Available Kombucha has been known as traditional medicine that can cure various diseases, such as hypercholesterol. Kombucha made of fermented sweetened tea using symbiotic growth of khamir and bacteria. Functional properties of kombucha related to metabolite that has been produced during fermentation process, glucuronic acid. The aim of this research was to get a fit carbon source that can produce kombucha which have highest glucuronic acid. The result showed that microbe that dominated at the beginning through the end of fermentation process was a group of khamir, i.e 1.81x107 ; 1.43x106 ; 2.40x107 ; 7.00x104 CFU/mL for 1, 4, 7, and 10% of additive coconut sugar. Kombucha at 4% of coconut sugar yielded 8.86 ppm of glucuronic acid. Meanwhile, kombucha with 10% of coconut sugar yielded 6.22 ppm of glucuronic acid. Total acid has no corelation with glucuronid acid formation during the fermentation process.

Sugar-Based Ethanol Biorefinery: Ethanol, Succinic Acid and By-Product Production

Energy Technology Data Exchange (ETDEWEB)

Donal F. Day

2009-03-31

The work conducted in this project is an extension of the developments itemized in DE-FG-36-04GO14236. This program is designed to help the development of a biorefinery based around a raw sugar mill, which in Louisiana is an underutilized asset. Some technical questions were answered regarding the addition of a biomass to ethanol facility to existing sugar mills. The focus of this work is on developing technology to produce ethanol and valuable by-products from bagasse. Three major areas are addressed, feedstock storage, potential by-products and the technology for producing ethanol from dilute ammonia pre-treated bagasse. Sugar mills normally store bagasse in a simple pile. During the off season there is a natural degradation of the bagasse, due to the composting action of microorganisms in the pile. This has serious implications if bagasse must be stored to operate a bagasse/biorefinery for a 300+ day operating cycle. Deterioration of the fermentables in bagasse was found to be 6.5% per month, on pile storage. This indicates that long term storage of adequate amounts of bagasse for year-round operation is probably not feasible. Lignin from pretreatment seemed to offer a potential source of valuable by-products. Although a wide range of phenolic compounds were present in the effluent from dilute ammonia pretreatment, the concentrations of each (except for benzoic acid) were too low to consider for extraction. The cellulosic hydrolysis system was modified to produce commercially recoverable quantities of cellobiose, which has a small but growing market in the food process industries. A spin-off of this led to the production of a specific oligosaccharide which appears to have both medical and commercial implications as a fungal growth inhibitor. An alternate use of sugars produced from biomass hydrolysis would be to produce succinic acid as a chemical feedstock for other conversions. An organism was developed which can do this bioconversion, but the economics of

Kinetics of ethanol production by immobilized Kluyveromyces marxianus cells at varying sugar concentrations of Jerusalem artichoke juice

Energy Technology Data Exchange (ETDEWEB)

Bajpai, P.; Margaritis, A.

1987-08-01

Kinetics of ethanol fermentation at varying sugar concentrations of Jerusalem artichoke tuber extract has been studied using Kluyveromyces marxianus cells immobilized in calcium alginate gel beads. A maximum ethanol concentration of 111 g/l was achieved at an initial sugar concentration of 260 g/l in 20 hours, when the immobilized cell concentration in the calcium alginate beads was 53.3 g dry wt./l bead volume. Ethanol yield remained almost unaffected by initial sugar concentration up to 250 g/l and was found to be about 88% of the theoretical. Maximum rate of ethanol production decreased from 22.5 g ethanol/l/h to 10.5 g ethanol/l/h while the maximum rate of total sugars utilization decreased from 74.9 g sugars/l/h to 28.5 g sugars/l/h as the initial substrate concentration was increased from 100 to 300 g/l. The concentration of free cells in the fermentation broth was low.

Identification of fermentation inhibitors in wood hydrolyzates and removal of inhibitors by ion exchange and liquid-liquid extraction

Science.gov (United States)

Luo, Caidian

1998-12-01

Common methods employed in the ethanol production from biomass consist of chemical or enzymatic degradation of biomass into sugars and then fermentation of sugars into ethanol or other chemicals. However, some degradation products severely inhibit the fermentation processes and substantially reduce the efficiency of ethanol production. How to remove inhibitors from the reaction product mixture and increase the production efficiency are critical in the commercialization of any processes of energy from biomass. The present study has investigated anion exchange and liquid-liquid extraction as potential methods for inhibitor removal. An analytical method has been developed to identify the fermentation inhibitors in a hydrolyzate. The majority of inhibitors present in hybrid poplar hydrolyzate have positively been identified. Ion exchange with weak basic Dowex-MWA-1 resin has been proved to be an effective mean to remove fermentation inhibitors from hybrid poplar hydrolyzate and significantly increase the fermentation productivity. Extraction with n-butanol might be a preferred way to remove inhibitors from wood hydrolyzates and improve the fermentability of sugars in the hydrolyzates. n-Butanol also removes some glucose, mannose and xylose from the hydrolyzate. Inhibitor identification reveals that lignin and sugar degradation compounds including both aromatic and aliphatic aldehydes and carboxylic acids formed in hydrolysis, plus fatty acids and other components from wood extractives are major fermentation inhibitors in Sacchromyces cerevisiae fermentation. There are 35 components identified as fermentation inhibitors. Among them, 4-hydroxy benzoic acid, 3,4-dihydroxy benzoic acid, syringic acid, syringaldehyde, and ferulic acid are among the most abundant aromatic inhibitors in hybrid poplar hydrolyzate. The conversion of aldehyde groups into carboxylic acid groups in the nitric acid catalyzed hydrolysis reduces the toxicity of the hydrolyzate. A wide spectrum of

Extraction of hemicelluloses from wood in a pulp biorefinery, and subsequent fermentation into ethanol

International Nuclear Information System (INIS)

Boucher, Jérémy; Chirat, Christine; Lachenal, Dominique

2014-01-01

Highlights: • Hemicellulosic ethanol from softwood hemicelluloses in a pulp mill. • Comparison of acid hydrolysis and autohydrolysis to extract hemicelluloses. • Effects of the extraction process conditions on inhibitors concentrations. • Effects of inhibitors on fermentation. - Abstract: This study deals with the production of ethanol and paper pulp in a kraft pulp mill. The use of an acid hydrolysis or a two-step treatment composed of an autohydrolysis followed by a secondary acid hydrolysis was studied. Acid hydrolysis allowed the extraction of higher quantities of sugars but led also to higher degradations of these sugars into inhibitors of fermentation. The direct fermentation of a hydrolysate resulting from an acid hydrolysis gave excellent yields after 24 h. However, the fermentation of hydrolysates after their concentration proved to be impossible. The study of the impact of the inhibitors on the fermentations showed that organic acids, and more specifically formic acid and acetic acid were greatly involved in the inhibition

Pre-treatment and ethanol fermentation potential of olive pulp at different dry matter concentrations

Energy Technology Data Exchange (ETDEWEB)

Haagensen, Frank [Bioprocess Science and Technology group, Biocentrum-DTU, Building 227, Technical University of Denmark, 2800 Lyngby (Denmark); Skiadas, Ioannis V.; Gavala, Hariklia N.; Ahring, Birgitte K. [Bioprocess Science and Technology group, Biocentrum-DTU, Building 227, Technical University of Denmark, 2800 Lyngby (Denmark); Copenhagen Institute of Technology (Aalborg University Copenhagen), Section for Sustainable Biotechnology, Department of Biotechnology, Chemistry and Environmental Engineering, Lautrupvang 15, DK 2750 Ballerup (Denmark)

2009-11-15

Renewable energy sources have received increased interest from the international community with biomass being one of the oldest and the most promising ones. In the concept of exploitation of agro-industrial residues, the present study investigates the pre-treatment and ethanol fermentation potential of the olive pulp, which is the semi solid residue generated from the two-phase processing of the olives for olive oil production. Wet oxidation and enzymatic hydrolysis have been applied aiming at the enhancement of carbohydrates' bioavailability. Different concentrations of enzymes and enzymatic durations have been tested. Both wet oxidation and enzymic treatment were evaluated based on the ethanol obtained in a subsequent fermentation step by Saccharomyces cerevisiae and Thermoanaerobacter mathranii. It was found that a four-day hydrolysis time was adequate for a satisfactory release of glucose and xylose. The combination of wet oxidation and enzymatic hydrolysis resulted in the glucose and xylose concentration increase of 138 and 444%, respectively, compared to 33 and 15% with only enzymes added. However, the highest ethanol production was obtained when only enzymic pre-treatment was applied, implying that wet oxidation is not a recommended pre-treatment process for olive pulp at the conditions tested. It was also showed that increased dry matter concentration did not have a negative effect on the release of sugars, indicating that the cellulose and xylan content of the olive pulp is relatively easily available. The results of the experiments in batch processes clearly emphasize that the simultaneous saccharification and fermentation (SSF) mode is advantageous in comparison with the separate hydrolysis and fermentation (SHF) mode concerning process contamination. (author)

Fermentative Hydrogen Production: Influence of Application of Mesophilic and Thermophilic Bacteria on Mass and Energy Balances

NARCIS (Netherlands)

Foglia, D.; Wukovits, W.; Friedl, A.; Vrije, de G.J.; Claassen, P.A.M.

2011-01-01

Fermentation of biomass residues and second generation biomasses is a possible way to enable a sustainable production of hydrogen. The HYVOLUTION-project investigates the production of hydrogen by a 2-stage fermentation process of biomass. It consists of a dark fermentation step of sugars to produce

Fermentation of Acid-pretreated Corn Stover to Ethanol Without Detoxification Using Pichia stipitis

Science.gov (United States)

Agbogbo, Frank K.; Haagensen, Frank D.; Milam, David; Wenger, Kevin S.

In this work, the effect of adaptation on P. stipitis fermentation using acidpretreated corn stover hydrolyzates without detoxification was examined. Two different types of adaptation were employed, liquid hydrolyzate and solid state agar adaptation. Fermentation of 12.5% total solids undetoxified acid-pretreated corn stover was performed in shake flasks at different rotation speeds. At low rotation speed (100 rpm), both liquid hydrolyzate and solid agar adaptation highly improved the sugar consumption rate as well as ethanol production rate compared to the wild-type strains. The fermentation rate was higher for solid agar-adapted strains compared to liquid hydrolyzate-adapted strains. At a higher rotation speed (150 rpm), there was a faster sugar consumption and ethanol production for both the liquid-adapted and the wild-type strains. However, improvements in the fermentation rate between the liquid-adapted and wild strains were less pronounced at the high rotation speed.

STUDY OF THE EFFECTS SHOWN BY THE ACTION OF VARIOUS MICROORGANISMS ON THE LACTIC FERMENTATION OF JUICES

Directory of Open Access Journals (Sweden)

Iuliana Manea

2010-01-01

Full Text Available Research has established the most effective lactic acid bacteria used for fermentation of fruit and vegetables juices. The cultures were used for Bifidobacteria, Lactobacillus acidophilus and culture of micro flora obtained spontaneous shoots. Lactic fermented juice was obtained from cabbage, carrots and beetroot. Working in these variants were determined lactic fermentation parameters and some of the bioactive compounds from this process: pH, reducing sugars, viable cell counts. Determination of reducing sugars calculated as glucose was conducted using the 3.5 dinitrosalicilic acid method (DNS method, pH was determined with a pH meter electronics. Chemical parameters listed were determined every two hours during the first 24 hours, then 48 and 72 hours in thermostatic conditions at 37 degrees C and 7 days storage at refrigerator temperature. At the end of the lactic fermentation, the lowest pH 4.31, which also provide juice conservation was obtained using a pure culture of Lactobacillus acidophilus. Reducing sugar is metabolized significantly when the juice of beetroot, fermented with Lactobacillus acidophilus culture, 75.19%. The results may be an argument for obtaining juice fermented lactic acid, which are popular functional foods, to obtain a chemical composition and sensory their optimum.

Continuous alcoholic fermentation

Energy Technology Data Exchange (ETDEWEB)

Smidrkal, M; Nejedly, A

1956-01-01

Results are given of investigations on the continuous production of ethanol on a laboratory and on a semi-commercial scale. The suggested devices are particularly described. Under constant conditions the production cycle required 12 to 17 days, the acidity being 4.0 to 415 ml. 0.1 N NaOH/100 ml and the concentration of fermented wort 10.5 to 11%. The maximum production from 1 h of fermentation space during 24 h was 8.67 l of absolute alcohol when the efflux was divided into several basins; when the efflux of sweet wort was collected into one basin only, the maximum production was 7.20 l of absolute alcohol. The amount of alcohol produced was 62.20 l/100 kg sugar.

Determination of expected alcohol yield from molasses by laboratory fermentation

Energy Technology Data Exchange (ETDEWEB)

Medintseva, L L

1960-01-01

Molasses (750 g, 18 to 19% dry weight) in 31 media, supplemented with nutrients was fermented with the industrial yeast strain. The expected alcohol yield was calculated for 1 kg conventional starch as B = V/P..pi.. 0.95, where V is the amount of alcohol distilled from the fermented medium in ml, P is the weight of molasses in g, is the fermentable sugar content of the molasses in percent, and 0.95 is the conversion factor from sucrose to starch.

Treatment of wastewaters and methane fermentation

Energy Technology Data Exchange (ETDEWEB)

Lescure, J P; Bourlet, P

1980-01-01

The laboratory, pilot plant, and industrial scale experiments were conducted on the anaerobic fermentation of spent sugar beet pulps and wastewater from wineries. The product of the fermentation was a gas typically containing CH/sub 4/ 65, CO/sub 2/ 15, H/sub 2/S 2.4, 0.3, N 0.8, and nonidentified substances 16.1 volume %. A 500 L pilot plant could process 10 kg/day of the spent beet pulp containing 20% solids and produce 500-600 L/day gas. The conversion of organic C was 66-91%.

Sugar-induced cephalic-phase insulin release is mediated by a T1r2+T1r3-independent taste transduction pathway in mice.

Science.gov (United States)

Glendinning, John I; Stano, Sarah; Holter, Marlena; Azenkot, Tali; Goldman, Olivia; Margolskee, Robert F; Vasselli, Joseph R; Sclafani, Anthony

2015-09-01

Sensory stimulation from foods elicits cephalic phase responses, which facilitate digestion and nutrient assimilation. One such response, cephalic-phase insulin release (CPIR), enhances glucose tolerance. Little is known about the chemosensory mechanisms that activate CPIR. We studied the contribution of the sweet taste receptor (T1r2+T1r3) to sugar-induced CPIR in C57BL/6 (B6) and T1r3 knockout (KO) mice. First, we measured insulin release and glucose tolerance following oral (i.e., normal ingestion) or intragastric (IG) administration of 2.8 M glucose. Both groups of mice exhibited a CPIR following oral but not IG administration, and this CPIR improved glucose tolerance. Second, we examined the specificity of CPIR. Both mouse groups exhibited a CPIR following oral administration of 1 M glucose and 1 M sucrose but not 1 M fructose or water alone. Third, we studied behavioral attraction to the same three sugar solutions in short-term acceptability tests. B6 mice licked more avidly for the sugar solutions than for water, whereas T1r3 KO mice licked no more for the sugar solutions than for water. Finally, we examined chorda tympani (CT) nerve responses to each of the sugars. Both mouse groups exhibited CT nerve responses to the sugars, although those of B6 mice were stronger. We propose that mice possess two taste transduction pathways for sugars. One mediates behavioral attraction to sugars and requires an intact T1r2+T1r3. The other mediates CPIR but does not require an intact T1r2+T1r3. If the latter taste transduction pathway exists in humans, it should provide opportunities for the development of new treatments for controlling blood sugar. Copyright © 2015 the American Physiological Society.

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...

Effect of Agave tequilana age, cultivation field location and yeast strain on tequila fermentation process.

Science.gov (United States)

Pinal, L; Cornejo, E; Arellano, M; Herrera, E; Nuñez, L; Arrizon, J; Gschaedler, A

2009-05-01

The effect of yeast strain, the agave age and the cultivation field location of agave were evaluated using kinetic parameters and volatile compound production in the tequila fermentation process. Fermentations were carried out with Agave juice obtained from two cultivation fields (CF1 and CF2), as well as two ages (4 and 8 years) and two Saccharomyces cerevisiae yeast strains (GU3 and AR5) isolated from tequila fermentation must. Sugar consumption and ethanol production varied as a function of cultivation field and agave age. The production of ethyl acetate, 1-propanol, isobutanol and amyl alcohols were influenced in varying degrees by yeast strain, agave age and cultivation field. Methanol production was only affected by the agave age and 2-phenylethanol was influenced only by yeast strain. This work showed that the use of younger Agave tequilana for tequila fermentation resulted in differences in sugar consumption, ethanol and volatile compounds production at the end of fermentation, which could affect the sensory quality of the final product.

Fermentation of Agave tequilana juice by Kloeckera africana: influence of amino-acid supplementations.

Science.gov (United States)

Valle-Rodríguez, Juan Octavio; Hernández-Cortés, Guillermo; Córdova, Jesús; Estarrón-Espinosa, Mirna; Díaz-Montaño, Dulce María

2012-02-01

This study aimed to improve the fermentation efficiency of Kloeckera africana K1, in tequila fermentations. We investigated organic and inorganic nitrogen source requirements in continuous K. africana fermentations fed with Agave tequilana juice. The addition of a mixture of 20 amino-acids greatly improved the fermentation efficiency of this yeast, increasing the consumption of reducing sugars and production of ethanol, compared with fermentations supplemented with ammonium sulfate. The preference of K. africana for each of the 20 amino-acids was further determined in batch fermentations and we found that asparagine supplementation increased K. africana biomass production, reducing sugar consumption and ethanol production (by 30, 36.7 and 45%, respectively) over fermentations supplemented with ammonium sulfate. Therefore, asparagine appears to overcome K. africana nutritional limitation in Agave juice. Surprisingly, K. africana produced a high concentration of ethanol. This contrasts to poor ethanol productivities reported for other non-Saccharomyces yeasts indicating a relatively high ethanol tolerance for the K. africana K1 strain. Kloeckera spp. strains are known to synthesize a wide variety of volatile compounds and we have shown that amino-acid supplements influenced the synthesis by K. africana of important metabolites involved in the bouquet of tequila. The findings of this study have revealed important nutritional limitations of non-Saccharomyces yeasts fermenting Agave tequilana juice, and have highlighted the potential of K. africana in tequila production processes.

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.

Characterization of bioactive compounds from monascus purpureus fermented different cereal substrates

Directory of Open Access Journals (Sweden)

Eva Ivanišová

2017-01-01

Full Text Available Solid-state fermenting of cereals by Monascus is interesting strategy to produce cereals with more beneficial components.  The objective of this study was to determine selected primary and secondary metabolites in cereals (rice, wheat, barley, sorghum, corn, buckwheat fermented by Monascus purpreus and subsequently compare amount of these compounds with control sample (cereals without Monascus. In fermented cereals was determined higher protein, fat, reducing sugars, crude fiber and ash content with compare to non-fermented cereals. The antioxidant activity measured by DPPH assay, ABTS assay as well as reducing power assay was also higher in fermented Monascus cereals with the best results in rice (3.09 ±0.02; 62.9 ±2.24; 43.19 ±2.07 mg TEAC per g of dry weight. Sample of fermented rice contained the highest level of total polyphenols (15.31 ±3.62 mg GAE per g of dry weight, total flavonoids (1.65 mg QE per g of dry weight and total phenolic acids (9.47 ±0.56 mg CAE per g of dry weight. In fermented cereals was also determined higher contact of reducing sugars (highest value in rice 246.97 ±7.96 mg GE per g, proteins (highest value in buckwheat 28.47 ±1.24%, ash (highest value in sorghum 2.74 ±0.08% and fat (highest value in corn 4.89 ±0.03% with compare to non-fermented samples. Results of crude fiber content of both - fermented and non-fermented cereals were balanced with similar values. Results of this study shown that Monascus purpureus fermented cereal substrates might be a potential sources of several bioactive compounds in food products.

Improving lactic acid productivity from wheat straw hydrolysates by membrane integrated repeated batch fermentation under non-sterilized conditions

DEFF Research Database (Denmark)

Zhang, Yuming; Chen, Xiangrong; Qi, Benkun

2014-01-01

to eliminate the sequential utilization of mixed sugar and feedback inhibition during batch fermentation, membrane integrated repeated batch fermentation (MIRB) was used to improve LA productivity. With MIRB, a high cell density was obtained and the simultaneous fermentation of glucose, xylose and arabinose...

Soya beans and maize : the effect of chemical and physical structure of cell wall polysaccharides on fermentation kinetics

NARCIS (Netherlands)

Laar, van H.

2000-01-01

The analysis of the relationship between cell wall composition and fermentation of endosperm cell walls of soya beans and maize was approached from three different angles. Firstly, the fermentation (rate and extent of fermentation, the sugar degradation pattern, and volatile fatty acid

Fermentation Potentials of Citrus Limon and Hibiscus Sabdariffa ...

African Journals Online (AJOL)

MASANAWA

body), fermentation produces lactic acid and lactate, carbon dioxide .... hydrometer, sugar refractor meter (made in. England) and ... The medium was allowed to gel and the. PDA plates were .... investment : Analysis of trends and issues in the ...

Fermentation of undetoxified sugarcane bagasse hydrolyzates using a two stage hydrothermal and mechanical refining pretreatment

Science.gov (United States)

Economical and environmentally friendly pretreatment technologies are required for commercial conversion of lignocellulosic feedstocks to fermentable sugars for fermentation to biofuels. In this paper, a novel pretreatment technology was developed for conversion of sugarcane bagasse into ethanol usi...

Development of an integrated approach for α-pinene recovery and sugar production from loblolly pine using ionic liquids

DEFF Research Database (Denmark)

Papa, Gabriella; Kirby, James; Murthy Konda, N. V. S. N.

2017-01-01

perspective for the production of advanced cellulosic biofuels. To date, there have been very few examples where a single conversion process has enabled recovery of both terpenes and fermentable sugars in an integrated fashion. We have used the ionic liquid (IL), 1-ethyl-3-methylimidazolium acetate [C2C1Im......][OAc] at 120 °C and 160 °C in conjunction with analytical protocols using GC-MS, to extract α-pinene and simultaneously pretreat the pine to generate high yields of fermentable sugars after saccharification. Compared to solvent extraction, the IL process enabled higher recovery rates for α-pinene, from three...... tissues type of loblolly pine, i.e. pine chips from forest residues (FC), stems from young pine (YW) and lighter wood (LW), while also generating high yields of fermentable sugars following saccharification. We propose that this combined terpene extraction/lignocellulose pretreatment approach may provide...

Overexpression of the WOX gene STENOFOLIA improves biomass yield and sugar release in transgenic grasses and display altered cytokinin homeostasis.

Directory of Open Access Journals (Sweden)

Hui Wang

2017-03-01

Full Text Available Lignocellulosic biomass can be a significant source of renewable clean energy with continued improvement in biomass yield and bioconversion strategies. In higher plants, the leaf blade is the central energy convertor where solar energy and CO2 are assimilated to make the building blocks for biomass production. Here we report that introducing the leaf blade development regulator STENOFOLIA (STF, a WOX family transcription factor, into the biofuel crop switchgrass, significantly improves both biomass yield and sugar release. We found that STF overexpressing switchgrass plants produced approximately 2-fold more dry biomass and release approximately 1.8-fold more solubilized sugars without pretreatment compared to controls. The biomass increase was attributed mainly to increased leaf width and stem thickness, which was also consistent in STF transgenic rice and Brachypodium, and appeared to be caused by enhanced cell proliferation. STF directly binds to multiple regions in the promoters of some cytokinin oxidase/dehydrogenase (CKX genes and represses their expression in all three transgenic grasses. This repression was accompanied by a significant increase in active cytokinin content in transgenic rice leaves, suggesting that the increase in biomass productivity and sugar release could at least in part be associated with improved cytokinin levels caused by repression of cytokinin degrading enzymes. Our study provides a new tool for improving biomass feedstock yield in bioenergy crops, and uncovers a novel mechanistic insight in the function of STF, which may also apply to other repressive WOX genes that are master regulators of several key plant developmental programs.

USE OF THE MICROWAVE RADIATION FOR UPGRADING OF A BIOMASS ALCOHOLIC FERMENTATION

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Anna Nowicka

2017-04-01

Full Text Available Perform pretreatment is crucial particularly in the case of the use of hard-degradable biomass, the biochemical susceptibility to degradation, for example, alcoholic fermentation is limited. Biomass disintegration processes lead to the destruction of compact structures and release of the organic substance to the phase dissolved in a resultant increase in the concentration of dissolved easily degradable organic substances. Effective pretreatment should meet several criteria, including ensuring the separation of lignin from cellulose, to increase the share of amorphous cellulose, provide a higher porosity substrates, eliminate waste sugars limit formation of inhibitors, minimize energy costs. The aim of this paper is to show the possibilities of using electromagnetic microwave radiation for pre-treatment plant biomass before the fermentation process of alcohol and comparison of the effectiveness of the described method with other commonly used techniques of pre-treatment. The substrate subjected to microwave treatment has a fast rate of hydrolysis and a high content of glucose in the hydrolyzate, which increases the efficiency of the production of bioethanol.

Fermented Citrus Lemon Reduces Liver Injury Induced by Carbon Tetrachloride in Rats

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Yi Jinn Lillian Chen

2018-01-01

Full Text Available Fermented lemon juice displays a variety of important biological activities, including anti-inflammatory and antioxidant capabilities. The aim of the present study is to investigate hepatic-protective effects of no-sugar-added fermented lemon juice (FLJ for liver inflammation caused by carbon tetrachloride (CCl4 in rats. Rats are divided into six groups: H2O, CCl4 + H2O, CCl4 + silymarin, and CCl4 plus three different FLJ doses by oral administration, respectively. The results show that the contents of plasma ALT and AST, hepatic lipid peroxidation, splenomegaly, and liver water are reduced significantly in rats under FLJ treatment, and pathological examination of liver fibrosis is improved. The reduced hepatic injury by increasing liver soluble protein and glutathione and albumin is observed in FLJ treated groups, and FLJ has comparable efficacies to medicine silymarin in liver therapies. The no-sugar-added FLJ differs from traditional fermentation by adding lots of sugar and prevents any hidden sugar intake while taking it as a complimentary treatment for liver inflammation. The green color and the taste of sourness are both associated with treating and healing the liver based on the five-element theory in traditional Chinese medicine, and the green and sour FLJ may be applied to the ancient theory in preventing hepatic injury accordingly.

Fed-batch production of green coconut hydrolysates for high-gravity second-generation bioethanol fermentation with cellulosic yeast.

Science.gov (United States)

Soares, Jimmy; Demeke, Mekonnen M; Van de Velde, Miet; Foulquié-Moreno, Maria R; Kerstens, Dorien; Sels, Bert F; Verplaetse, Alex; Fernandes, Antonio Alberto Ribeiro; Thevelein, Johan M; Fernandes, Patricia Machado Bueno

2017-11-01

The residual biomass obtained from the production of Cocos nucifera L. (coconut) is a potential source of feedstock for bioethanol production. Even though coconut hydrolysates for ethanol production have previously been obtained, high-solid loads to obtain high sugar and ethanol levels remain a challenge. We investigated the use of a fed-batch regime in the production of sugar-rich hydrolysates from the green coconut fruit and its mesocarp. Fermentation of the hydrolysates obtained from green coconut or its mesocarp, containing 8.4 and 9.7% (w/v) sugar, resulted in 3.8 and 4.3% (v/v) ethanol, respectively. However, green coconut hydrolysate showed a prolonged fermentation lag phase. The inhibitor profile suggested that fatty acids and acetic acid were the main fermentation inhibitors. Therefore, a fed-batch regime with mild alkaline pretreatment followed by saccharification, is presented as a strategy for fermentation of such challenging biomass hydrolysates, even though further improvement of yeast inhibitor tolerance is also needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of oxygen limitation on sugar metabolism in yeasts: a continuous-culture study of the Kluyver effect.

Science.gov (United States)

Weusthuis, R A; Visser, W; Pronk, J T; Scheffers, W A; van Dijken, J P

1994-04-01

Growth and metabolite formation were studied in oxygen-limited chemostat cultures of Saccharomyces cerevisiae CBS 8066 and Candida utilis CBS 621 growing on glucose or maltose at a dilution rate of 0.1 h-1. With either glucose or maltose S. cerevisiae could be grown under dual limitation of oxygen and sugar. Respiration and alcoholic fermentation occurred simultaneously and the catabolite fluxes through these processes were dependent on the magnitude of the oxygen feed. C. utilis could also be grown under dual limitation of glucose and oxygen. However, at very low oxygen feed rates (i.e. below 4 mmol l-1 h-1) growth was limited by oxygen only, as indicated by the high residual glucose concentration in the culture. In contrast to S. cerevisiae, C. utilis could not be grown anaerobically at a dilution rate of 0.1 h-1. With C. utilis absence of oxygen resulted in wash-out, despite the presence of ergosterol and Tween-80 in the growth medium. The behaviour of C. utilis with respect to maltose utilization in oxygen-limited cultures was remarkable: alcoholic fermentation did not occur and the amount of maltose metabolized was dependent on the oxygen supply. Oxygen-limited cultures of C. utilis growing on maltose always contained high residual sugar concentrations. These observations throw new light on the so-called Kluyver effect. Apparently, maltose is a non-fermentable sugar for C. utilis CBS 621, despite the fact that it can serve as a substrate for growth of this facultatively fermentative yeast. This is not due to the absence of key enzymes of alcoholic fermentation. Pyruvate decarboxylase and alcohol dehydrogenase were present at high levels in maltose-utilizing cells of C. utilis grown under oxygen limitation. It is concluded that the Kluyver effect, in C. utilis growing on maltose, results from a regulatory mechanism that prevents the sugar from being fermented. Oxygen is not a key factor in this phenomenon since under oxygen limitation alcoholic fermentation of

Phosphoric acid based pretreatment of switchgrass and fermentation of entire slurry to ethanol using a simplified process.

Science.gov (United States)

Wu, Wei; Rondon, Vanessa; Weeks, Kalvin; Pullammanappallil, Pratap; Ingram, Lonnie O; Shanmugam, K T

2018-03-01

Switchgrass (Alamo) was pretreated with phosphoric acid (0.75 and 1%, w/w) at three temperatures (160, 175 and 190 °C) and time (5, 7.5 and 10 min) using a steam gun. The slurry after pretreatment was liquefied by enzymes and the released sugars were fermented in a simultaneous saccharification and co-fermentation process to ethanol using ethanologenic Escherichia coli strain SL100. Among the three variables in pretreatment, temperature and time were critical in supporting ethanol titer and yield. Enzyme hydrolysis significantly increased the concentration of furans in slurries, apparently due to release of furans bound to the solids. The highest ethanol titer of 21.2 ± 0.3 g/L ethanol obtained at the pretreatment condition of 190-1-7.5 (temperature-acid concentration-time) and 10% solids loading accounted for 190 ± 2.9 g ethanol/kg of raw switch grass. This converts to 61.7 gallons of ethanol per ton of dry switchgrass, a value that is comparable to other published pretreatment conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

New roles in hemicellulosic sugar fermentation for the uncultivated Bacteroidetes family BS11

Energy Technology Data Exchange (ETDEWEB)

Solden, Lindsey M.; Hoyt, David W.; Collins, William B.; Plank, Johanna E.; Daly, Rebecca A.; Hildebrand, Erik; Beavers, Timothy J.; Wolfe, Richard; Nicora, Carrie D.; Purvine, Sam O.; Carstensen, Michelle; Lipton, Mary S.; Spalinger, Donald E.; Firkins, Jeffrey L.; Wolfe, Barbara A.; Wrighton, Kelly C.

2016-12-13

Ruminants have co-evolved with their gastrointestinal microbial communities that aid in the digestion of plant materials, providing energy for the host. The ability of this microbiome to adapt to altered host diets may dramatically impact the survival of wild ruminant populations, especially under future climate change scenarios. To identify microorganisms capable of degrading climatedriven increases in woody biomass in arctic and boreal regions, we sampled rumen fluids from Alaskan moose foraging along a seasonal lignocellulose gradient. Winter diets with increased hemicellulose and lignin enriched for BS11, a Bacteroidetes family lacking cultivated or genomically sampled representatives. Our findings show that the BS11 are cosmopolitan host-associated bacteria prevalent in gastrointestinal tracts of ruminants and other mammals, including humans. Metagenomic reconstruction yielded the first five BS11 genomes, phylogenetically resolving two genera within this taxonomically undefined family. Genome-enabled metabolic analyses uncovered multiple pathways for degrading hemicellulose sugars to short-chain fatty acids, metabolites vital for ruminant energy. Active hemicellulosic fermentation, as well as butyrate and acetate production, were validated by shotgun proteomics and rumen metabolite detection using NMR, illuminating the vital role BS11 play in carbon transformations within the rumen. These results demonstrate that woody biomass selects for BS11 members, providing arctic herbivores with metabolic redundancy to sustain energy generation in a changing vegetative environment.

Plant-based Paste Fermented by Lactic Acid Bacteria and Yeast: Functional Analysis and Possibility of Application to Functional Foods

Directory of Open Access Journals (Sweden)

Shinsuke Kuwaki

2012-01-01

Full Text Available A plant-based paste fermented by lactic acid bacteria and yeast (fermented paste was made from various plant materials. The paste was made of fermented food by applying traditional food-preservation techniques, that is, fermentation and sugaring. The fermented paste contained major nutrients (carbohydrates, proteins, and lipids, 18 kinds of amino acids, and vitamins (vitamin A, B 1 B 2 , B 6 , B 12 , E, K, niacin, biotin, pantothenic acid, and folic acid. It contained five kinds of organic acids, and a large amount of dietary fiber and plant phytochemicals. Sucrose from brown sugar, used as a material, was completely resolved into glucose and fructose. Some physiological functions of the fermented paste were examined in vitro. It was demonstrated that the paste possessed antioxidant, antihypertensive, antibacterial, anti-inflammatory, anti-allergy and anti-tyrosinase activities in vitro. It was thought that the fermented paste would be a helpful functional food with various nutrients to help prevent lifestyle diseases.

Evaluation of stress tolerance and fermentative behavior of indigenous Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Cíntia Lacerda Ramos

2013-09-01

Full Text Available Sixty six indigenous Saccharomyces cerevisiae strains were evaluated in stressful conditions (temperature, osmolarity, sulphite and ethanol tolerance and also ability to flocculate. Eighteen strains showed tolerant characteristics to these stressful conditions, growing at 42 ºC, in 0.04% sulphite, 1 mol L-1 NaCl and 12% ethanol. No flocculent characteristics were observed. These strains were evaluated according to their fermentative performance in sugar cane juice. The conversion factors of substrates into ethanol (Yp/s, glycerol (Yg/s and acetic acid (Yac/s, were calculated. The highest values of Yp/s in sugar cane juice fermentation were obtained by four strains, one isolated from fruit (0.46 and the others from sugar cane (0.45, 0.44 and 0.43. These values were higher than the value obtained using traditional yeast (0.38 currently employed in the Brazilian bioethanol industry. The parameters Yg/s and Yac/s were low for all strains. The UFLA FW221 presented the higher values for parameter related to bioethanol production. Thus, it was tested in co-culture with Lactobacillus fermentum. Besides this, a 20-L vessel for five consecutive batches of fermentation was performed. This strain was genetically stable and remained viable during all batches, producing high amounts of ethanol. The UFLA FW221 isolated from fruit was suitable to produce bioethanol in sugar cane juice. Therefore, the study of the biodiversity of yeasts from different environmental can reveal strains with desired characteristics to industrial applications.

Xylose Fermentation by Saccharomyces cerevisiae: Challenges and Prospects

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Danuza Nogueira Moysés

2016-02-01

Full Text Available Many years have passed since the first genetically modified Saccharomyces cerevisiae strains capable of fermenting xylose were obtained with the promise of an environmentally sustainable solution for the conversion of the abundant lignocellulosic biomass to ethanol. Several challenges emerged from these first experiences, most of them related to solving redox imbalances, discovering new pathways for xylose utilization, modulation of the expression of genes of the non-oxidative pentose phosphate pathway, and reduction of xylitol formation. Strategies on evolutionary engineering were used to improve fermentation kinetics, but the resulting strains were still far from industrial application. Lignocellulosic hydrolysates proved to have different inhibitors derived from lignin and sugar degradation, along with significant amounts of acetic acid, intrinsically related with biomass deconstruction. This, associated with pH, temperature, high ethanol, and other stress fluctuations presented on large scale fermentations led the search for yeasts with more robust backgrounds, like industrial strains, as engineering targets. Some promising yeasts were obtained both from studies of stress tolerance genes and adaptation on hydrolysates. Since fermentation times on mixed-substrate hydrolysates were still not cost-effective, the more selective search for new or engineered sugar transporters for xylose are still the focus of many recent studies. These challenges, as well as under-appreciated process strategies, will be discussed in this review.

Sugar cane bagasse prehydrolysis using hot water

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D. Abril

2012-03-01

Full Text Available Results are presented on the hot water prehydrolysis of sugar cane bagasse for obtaining ethanol by fermentation. The experimental study consisted of the determination of the effect of temperature and time of prehydrolysis on the extraction of hemicelluloses, with the objective of selecting the best operating conditions that lead to increased yield of extraction with a low formation of inhibitors. The study, carried out in a pilot plant scale rotational digester, using a 3² experimental design at temperatures of 150-190ºC and times of 60-90 min, showed that it is possible to perform the hot water prehydrolysis process between 180-190ºC in times of 60-82 min, yielding concentrations of xylose > 35 g/L, furfural < 2.5 g/L, phenols from soluble lignin < 1.5 g/L, and concentrations < 3.0 g/L of hemicelluloses in the cellolignin residue. These parameters of temperature and prehydrolysis time could be used for the study of the later hydrolysis and fermentation stages of ethanol production from sugar cane bagasse.

Bioreactors for lignocellulose conversion into fermentable sugars for production of high added value products.

Science.gov (United States)

Liguori, Rossana; Ventorino, Valeria; Pepe, Olimpia; Faraco, Vincenza

2016-01-01

Lignocellulosic biomasses derived from dedicated crops and agro-industrial residual materials are promising renewable resources for the production of fuels and other added value bioproducts. Due to the tolerance to a wide range of environments, the dedicated crops can be cultivated on marginal lands, avoiding conflict with food production and having beneficial effects on the environment. Besides, the agro-industrial residual materials represent an abundant, available, and cheap source of bioproducts that completely cut out the economical and environmental issues related to the cultivation of energy crops. Different processing steps like pretreatment, hydrolysis and microbial fermentation are needed to convert biomass into added value bioproducts. The reactor configuration, the operative conditions, and the operation mode of the conversion processes are crucial parameters for a high yield and productivity of the biomass bioconversion process. This review summarizes the last progresses in the bioreactor field, with main attention on the new configurations and the agitation systems, for conversion of dedicated energy crops (Arundo donax) and residual materials (corn stover, wheat straw, mesquite wood, agave bagasse, fruit and citrus peel wastes, sunflower seed hull, switchgrass, poplar sawdust, cogon grass, sugarcane bagasse, sunflower seed hull, and poplar wood) into sugars and ethanol. The main novelty of this review is its focus on reactor components and properties.

The influence of molasses addition on the kinetics of alcoholic fermentation of whey using Kluyveromyces marxianus yeast

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Damir Stanzer

2004-01-01

Full Text Available Kinetics of alcoholic fermentation by yeast Kluyveromyces marxianusZIM 75 in various media based on whey and molasses were monitored. The fermentations were performed under static and semiaerobic conditions at 34°C. Deproteinized whey and molasses were mixed in various proportions to give final sugar mass concentrations of 5%, 10% and 15% in medium. The experiments conducted showed that medium with 10 % of sugar (sucrose:lactose=1:1 is optimal for alcoholic fermentations in static and semiaerobic conditions. The best ethanol yield after 24 hours of fermentation was 4.05 % (V/V in static conditions and 4.9 % (V/V in semiaerobic conditions. The biomass yield was 7.78 g d.m./L in semiaerobic conditions and 3.19 g d.m./L in static conditions.

Sugar and ethanol production from woody biomass via supercritical water hydrolysis in a continuous pilot-scale system using acid catalyst.

Science.gov (United States)

Jeong, Hanseob; Park, Yong-Cheol; Seong, Yeong-Je; Lee, Soo Min

2017-12-01

The aim of this study were to efficiently produce fermentable sugars by continuous type supercritical water hydrolysis (SCWH) of Quercus mongolica at the pilot scale with varying acid catalyst loading and to use the obtained sugars for ethanol production. The SCWH of biomass was achieved in under one second (380°C, 230bar) using 0.01-0.1% H 2 SO 4 . With 0.05% H 2 SO 4 , 49.8% of sugars, including glucose (16.5% based on biomass) and xylose monomers (10.8%), were liberated from biomass. The hydrolysates were fermented with S. cerevisiae DXSP and D452-2 to estimate ethanol production. To prepare the fermentation medium, the hydrolysates were detoxified using activated charcoal and then concentrated. The ethanol yield of fermentation with S. cerevisiae DXSP was 14.1% (based on biomass). The proposed system has potential for improvement in yield through process optimization. After further development, it is expected to be a competitive alternative to traditional systems for ethanol production from woody biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fermentation of protopanaxadiol type ginsenosides (PD) with probiotic Bifidobacterium lactis and Lactobacillus rhamnosus.

Science.gov (United States)

Tan, Joanne Sh; Yeo, Chia-Rou; Popovich, David G

2017-07-01

Ginsenosides are believed to be the principal components behind the pharmacological actions of ginseng, and their bioactive properties are closely related to the type, position, and number of sugar moieties attached to the aglycone; thus, modification of the sugar chains may markedly change their biological activities. In this study, major protopanaxadiol type ginsenosides (PD) Rb1, Rc, and Rb2 were isolated from Panax ginseng and were transformed using two probiotic strains namely Bifidobacterium lactis Bi-07 and Lactobacillus rhamnosus HN001 to obtain specific deglycosylated ginsenosides. It was demonstrated that B. lactis transformed ginsenosides Rb1, Rc, and Rb2 to Rd within 1 h of fermentation and rare ginsenoside F2 by the conversion of Rd after 12-h fermentation. The maximum Rd concentration was 147.52 ± 1.45 μg/mL after 48-h fermentation as compared to 45.85 ± 0.71 μg/mL before fermentation. In contrast, L. rhamnosus transformed Rb1, Rc, and Rb2 into Rd as the final metabolite after 72-h fermentation. B. lactis displayed significantly (p fermentation. The present study suggests that the fermentation of major PD type ginsenosides with B. lactis Bi-07 may serve as an effective means to afford bioactive deglycosylated ginsenosides and to create novel ginsenoside extracts.

Oil Palm Frond Juice as Future Fermentation Substrate: A Feasibility Study

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Che Mohd Hakiman Che Maail

2014-01-01

Full Text Available Oil palm frond (OPF juice is a potential industrial fermentation substrate as it has high sugars content and the OPF are readily available daily. However, maximum sugars yield and storage stability of the OPF juice are yet to be determined. This study was conducted to determine the effect of physical pretreatment and storage duration of OPF petiole on sugars yield. Storage stability of OPF juice at different storing conditions was also investigated. It was found that OPF petiole squeezed by hydraulic pressing machine gave the highest sugars recovery at almost 40 g/kg, accounting for a recovery yield of 88%. Storage of OPF petiole up to 72 hrs prior to squeezing reduced the free sugars by 11 g/kg. Concentrated OPF juice with 95% water removal had the best storage stability at both 4 and 30°C, when it was stored for 10 days. Moreover, concentrated OPF syrup prepared by thermal processing did not give any Maillard effect on microbial growth. Based on our results, OPF juice meets all the criteria as a good fermentation substrate as it is renewable, consistently available, and easy to be obtained, it does not inhibit microbial growth and product formation, and it contains no impurities.

Oil Palm Frond Juice as Future Fermentation Substrate: A Feasibility Study

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Che Maail, Che Mohd Hakiman; Ariffin, Hidayah; Hassan, Mohd Ali; Shah, Umi Kalsom Md; Shirai, Yoshihito

2014-01-01

Oil palm frond (OPF) juice is a potential industrial fermentation substrate as it has high sugars content and the OPF are readily available daily. However, maximum sugars yield and storage stability of the OPF juice are yet to be determined. This study was conducted to determine the effect of physical pretreatment and storage duration of OPF petiole on sugars yield. Storage stability of OPF juice at different storing conditions was also investigated. It was found that OPF petiole squeezed by hydraulic pressing machine gave the highest sugars recovery at almost 40 g/kg, accounting for a recovery yield of 88%. Storage of OPF petiole up to 72 hrs prior to squeezing reduced the free sugars by 11 g/kg. Concentrated OPF juice with 95% water removal had the best storage stability at both 4 and 30°C, when it was stored for 10 days. Moreover, concentrated OPF syrup prepared by thermal processing did not give any Maillard effect on microbial growth. Based on our results, OPF juice meets all the criteria as a good fermentation substrate as it is renewable, consistently available, and easy to be obtained, it does not inhibit microbial growth and product formation, and it contains no impurities. PMID:25057489

Continuous butyric acid fermentation coupled with REED technology for enhanced productivity

DEFF Research Database (Denmark)

Baroi, George Nabin; Skiadas, Ioannis; Westermann, Peter

strains, C.tyrobutyricum seems the most promising for biological production of butyric acid as it is characterised by higher selectivity and higher tolerance to butyric acid. However, studies on fermentative butyric production from lignocellulosic biomasses are scarce in the international literature...... of continuous fermentation mode and in-situ acids removal by Reverse Enhanced Electro Dialysis (REED) resulted to enhanced sugars consumption rates when 60% PHWS was fermented. Specifically, glucose and xylose consumption rate increased by a factor of 6 and 39, respectively, while butyric acid productivity...

Continuous Ethanol Fermentation of Pretreated Lignocellulosic Biomasses, Waste Biomasses, Molasses and Syrup Using the Anaerobic, Thermophilic Bacterium Thermoanaerobacter italicus Pentocrobe 411

Science.gov (United States)

Andersen, Rasmus Lund; Jensen, Karen Møller; Mikkelsen, Marie Just

2015-01-01

Lignocellosic ethanol production is now at a stage where commercial or semi-commercial plants are coming online and, provided cost effective production can be achieved, lignocellulosic ethanol will become an important part of the world bio economy. However, challenges are still to be overcome throughout the process and particularly for the fermentation of the complex sugar mixtures resulting from the hydrolysis of hemicellulose. Here we describe the continuous fermentation of glucose, xylose and arabinose from non-detoxified pretreated wheat straw, birch, corn cob, sugar cane bagasse, cardboard, mixed bio waste, oil palm empty fruit bunch and frond, sugar cane syrup and sugar cane molasses using the anaerobic, thermophilic bacterium Thermoanaerobacter Pentocrobe 411. All fermentations resulted in close to maximum theoretical ethanol yields of 0.47–0.49 g/g (based on glucose, xylose, and arabinose), volumetric ethanol productivities of 1.2–2.7 g/L/h and a total sugar conversion of 90–99% including glucose, xylose and arabinose. The results solidify the potential of Thermoanaerobacter strains as candidates for lignocellulose bioconversion. PMID:26295944

La fermentation éthanolique. Les microorganismes Ethanol Fermentation. The Microorganisms

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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.

KINETICS OF GROWTH AND ETHANOL PRODUCTION ON DIFFERENT CARBON SUBSTRATES USING GENETICALLY ENGINEERED XYLOSE-FERMENTING YEAST

Science.gov (United States)

Saccharomyces cerevisiae 424A (LNH-ST) strain was used for fermentation of glucose and xylose. Growth kinetics and ethanol productivity were calculated for batch fermentation on media containing different combinations of glucose and xylose to give a final sugar concentra...

New alternatives for the fermentation process in the ethanol production from sugarcane: Extractive and low temperature fermentation

International Nuclear Information System (INIS)

Palacios-Bereche, Reynaldo; Ensinas, Adriano; Modesto, Marcelo; Nebra, Silvia A.

2014-01-01

Ethanol is produced in large scale from sugarcane in Brazil by fermentation of sugars and distillation. This is currently considered as an efficient biofuel technology, leading to significant reduction on greenhouse gases emissions. However, some improvements in the process can be introduced in order to improve the use of energy. In current distilleries, a significant fraction of the energy consumption occurs in the purification step – distillation and dehydration – since conventional fermentation systems employed in the industry require low substrate concentration, which must be distilled, consequently with high energy consumption. In this study, alternatives to the conventional fermentation processes are assessed, through computer simulation: low temperature fermentation and vacuum extractive fermentation. The aim of this study is to assess the incorporation of these alternative fermentation processes in ethanol production, energy consumption and electricity surplus produced in the cogeneration system. Several cases were evaluated. Thermal integration technique was applied. Results shown that the ethanol production increases between 3.3% and 4.8% and a reduction in steam consumption happens of up to 36%. About the electricity surplus, a value of 85 kWh/t of cane can be achieved when condensing – extracting steam turbines are used. - Highlights: • Increasing the wine concentration in the ethanol production from sugarcane. • Alternatives to the conventional fermentation process. • Low temperature fermentation and vacuum extractive fermentation. • Reduction of steam consumption through the thermal integration of the processes. • Different configurations of cogeneration system maximizing the electricity surplus

Continuous ethanol production using yeast immobilized on sugar-cane stalks

Energy Technology Data Exchange (ETDEWEB)

Vasconcelos, J.N. de [Alagoas Univ., Maceio, AL (Brazil). Dept. de Engenharia Quimica]. E-mail: jnunes@ctec.ufal.br; Lopes, C.E. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Antibioticos; Franca, F.P. de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica. Dept. de Engenharia Bioquimica

2004-09-01

Sugar-cane stalks, 2.0 cm long, were used as a support for yeast immobilization envisaging ethanol production. The assays were conducted in 38.5 L fermenters containing a bed of stalks with 50% porosity. The operational stability of the immobilized yeast, the efficiency and stability of the process, as well as the best dilution rate were evaluated. Molasses from demerara sugar production was used in the medium formulation. It was diluted to obtain 111.75 {+-} 1.51 g/L without any further treatment. Sulfuric acid was used to adjust the pH value to around 4.2. Every two days Kamoran HJ (10 ppm) or with a mixture containing penicillin (10 ppm) and tetracycline (10 ppm), was added to the medium. Ethanol yield and efficiency were 29.64 g/L.h and 86.40%, respectively, and the total reducing sugars conversion was 74.61% at a dilution rate of 0.83 h{sup -1}. The yeast-stalk system was shown to be stable for over a 60 day period at extremely variable dilution rates ranging from 0.05 h{sup -1} to 3.00 h{sup -1}. The concentration of immobilized cell reached around 109 cells/gram of dry sugar-cane stalk when the fermenter was operating at the highest dilution rate (3.00 h{sup -1}). (author)

Hydrocarbons by fermenting the juice of the Jerusalem artichoke

Energy Technology Data Exchange (ETDEWEB)

Joud, F R

1976-02-13

The artichoke juice containing nonfermentable insulins is acidified to pH 3- and heated at 95/sup 0/ for 30 to 40 minutes to hydrolyze the insulins into fermentable sugars which are then fermented to ethanol. The ethanol is dried and reacted with H/sub 2/SO/sub 4/ to form C/sub 2/H/sub 4/ which is treated at 300/sup 0/ under pressure with a powdered Ni catalyst to form alkanes, alkenes, and alkynes.

Estudo da fermentação alcoólica de soluções diluídas de diferentes açucares utilizando microcalorimetria de fluxo Study of the alcoholic fermentation of sugars diluted solutions through flow microcalorimetry

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Pedro L. O. Volpe

1997-10-01

Full Text Available The present study shows that with liquid nitrogen stored inocula of Saccharomyces cerevisiae, and standardized experimental procedure, flow microcalorimetry can be a valuable tool for monitoring in real time the alcoholic fermentation processes on line. The avaliation of cultural conditions contained different carbon sources for alcohol fermentation (sucrose, glucose, fructose, manose, maltose, galactose, molasses, honey and sugar cane and their effects on the heat output recording is discussed. Some examples of diauxic growth is given, where the microcalorimeters serves to detect the temporal order of succession of alternating metabolic pathways.

ACÚMULO DE CÁDMIO POR Saccharomyces cerevisiae FERMENTANDO MOSTO DE CALDO DE CANA ACCUMULATION OF CADMIUM BY Saccharomyces cerevisiae FERMENTING MUST OF SUGAR-CANE

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S.M.G. da SILVA

1998-10-01

Full Text Available O presente trabalho estudou o acúmulo de cádmio (Cd por Saccharomyces cerevisiae, fermentando mosto de caldo de cana com contaminações controladas, em níveis sub-tóxicos, do citado metal. O ensaio de fermentação foi conduzido em erlenmayers de 500 mL, acondicionados em estufa B.O.D. O mosto, não esterilizado, continha 12% de açúcares redutores totais (ART e pH 4,5. Para a contaminação controlada empregou-se cloreto de cádmio em quatro níveis de contaminações: 0,5; 1,0; 2,0 e 5,0 mg Cd kg-1 mosto. A inoculação do mosto foi executada com fermento de panificação (10% p/p. Após a fermentação (4 horas foram determinados, porcentagem de fermento no vinho centrifugado e teor alcoólico do mesmo. Na levedura separada por centrifugação, foram determinados peso úmido, matéria seca, proteína bruta e teores de cádmio por espectrofotometria de absorção atômica. Em todos os níveis de contaminação estudados houve acúmulo de Cd pela levedura.The aim of this paper is to study the absorption and cadmium (Cd concentration by Saccharomyces cerevisiae, fermenting must of sugar-cane, with control contamination, under toxic levels of cadmium (mg Cd kg-1 must. The fermentation was performed in 500 mL erlemmayers. Non-sterilized must showed 12% of total reducing sugar (w/w e pH 4,5. For the control contamination, was applied cadmium chloride, with four levels of contamination: 0,5; 1,0; 2,0 and 5,0 mg Cd kg-1 must. The inoculation of must was carried out with bread yeast (10% w/w. After fermentation (4 hours, samples were colected to evaluate cellular viability and yeast percentage. Fermenting mid was centrifuged and analysis of mid without yeast and raw yeast were performed. The alcohol content was measured , as well as the total humid weight for the yeast material, raw protein and heavy metal by atomic absorption spectroscopy. Watch all level studied have accumulation of cadmium at yeast.

Microbiological and physicochemical analysis of pumpkin juice fermentation by the basidiomycetous fungus Ganoderma lucidum.

Science.gov (United States)

Zhao, Jing; Liu, Wei; Chen, Dong; Zhou, Chunli; Song, Yi; Zhang, Yuyu; Ni, Yuanying; Li, Quanhong

2015-02-01

A new protocol for processing of pumpkin juice was set up which included fermentation by the basidiomycete Ganoderma lucidum at 28 °C for 7 d. The growth curve of G. lucidum in pumpkin juice was successfully (R(2)  = 0.99) fitted by a 4-parameter logistic model and the ideal highest biomass was estimated to be 4.79 g/L. G. lucidum was found to have a significant acidification effect on pumpkin juice. The lowest pH (4.05 ± 0.05) and highest total titratable acidity (14.31 ± 0.16 mL 0.1 M NaOH/100 mL) were found on the 4th day during fermentation. Sugars in pumpkin juice fermented with G. lucidum showed a significant decrease, especially glucose and fructose. On the contrary, the release of exo-polysaccharides and free amino acids greatly enriched the pumpkin juice. The variation of color index and viscosity also mirrored the above behavior. Based on headspace solid phase microextraction and gas chromatography-mass spectrometry, 68 volatile compounds were identified, including 17 esters, 14 alcohols, 13 phenyl compounds, 11 aldehydes, 8 ketones, 3 acids, 1 furan, and 1 benzothiazole. The pumpkin juices fermented for different days were markedly differentiated with principal component analysis and the fermentation process was tentatively divided into 3 periods: the booming (from the 1st to 4th day), steady (from the 5th to 6th day), and decline (the 7th day) period. © 2014 Institute of Food Technologists®

In vitro fermentation of sugar beet arabino-oligosaccharides by fecal microbiota obtained from patients with ulcerative colitis to selectively stimulate the growth of Bifidobacterium spp. and Lactobacillus spp

DEFF Research Database (Denmark)

Vigsnæs, Louise Kristine; Holck, Jesper; Meyer, Anne S.

in the pathogenesis of ulcerative colitis (UC), an inflammatory bowel disease, and compositional changes have been observed in the colonic microbiota by us as well as by other research groups 1-3. Since bifidobacteria and lactobacilli may excert anti-inflammatory effects, a reduced level of these commensal bacteria...... may compromise the colon health and favor intestinal inflammation. In this study, selective stimulation of fecal bifidobacteria and lactobacilli from healthy subjects and UC patients in remission or with active disease were investigated using arabino-oligosaccharides (AOS; DP2-10) derived from sugar...... beet pulp. The fermentative-induced changes were compared to those for fructo-oligosaccharides (FOS), which are known to have a prebiotic effect. The fermentation studies were carried out using a validated small-scale static batch system, and changes in the fecal microbial communities and metabolites...

Effect of micro-organism and particle size on fermentation of ...

African Journals Online (AJOL)

Aziwo Niba

2013-06-26

Jun 26, 2013 ... fermentation for pH, sugar and organic acids analysis. .... performance liquid chromatography (HPLC) according to the ... are the sums of maltose, glucose and fructose concentrations. n=number of observations per mean.

Potential of potassium hydroxide pretreatment of switchgrass for fermentable sugar production.

Science.gov (United States)

Sharma, Rajat; Palled, Vijaykumar; Sharma-Shivappa, Ratna R; Osborne, Jason

2013-02-01

Chemical pretreatment of lignocellulosic biomass has been extensively investigated for sugar generation and subsequent fuel production. Alkaline pretreatment has emerged as one of the popular chemical pretreatment methods, but most attempts thus far have utilized NaOH for the pretreatment process. This study aimed at investigating the potential of potassium hydroxide (KOH) as a viable alternative alkaline reagent for lignocellulosic pretreatment based on its different reactivity patterns compared to NaOH. Performer switchgrass was pretreated at KOH concentrations of 0.5-2% for varying treatment times of 6-48 h, 6-24 h, and 0.25-1 h at 21, 50, and 121 °C, respectively. The pretreatments resulted in the highest percent sugar retention of 99.26% at 0.5%, 21 °C, 12 h while delignification up to 55.4% was observed with 2% KOH, 121 °C, 1 h. Six pretreatment conditions were selected for subsequent enzymatic hydrolysis with Cellic CTec2® for sugar generation. The pretreatment condition of 0.5% KOH, 24 h, 21 °C was determined to be the most effective as it utilized the least amount of KOH while generating 582.4 mg sugar/g raw biomass for a corresponding percent carbohydrate conversion of 91.8%.

Fermentative capabilities and volatile compounds produced by Kloeckera/Hanseniaspora and Saccharomyces yeast strains in pure and mixed cultures during Agave tequilana juice fermentation.

Science.gov (United States)

González-Robles, Ivonne Wendolyne; Estarrón-Espinosa, Mirna; Díaz-Montaño, Dulce María

2015-09-01

The fermentative and aromatic capabilities of Kloeckera africana/Hanseniaspora vineae K1, K. apiculata/H. uvarum K2, and Saccharomyces cerevisiae S1 and S2 were studied in pure and mixed culture fermentations using Agave tequila juice as the culture medium. In pure and mixed cultures, Kloeckera/Hanseniaspora strains showed limited growth and sugar consumption, as well as low ethanol yield and productivity, compared to S. cerevisiae, which yielded more biomass, ethanol and viable cell concentrations. In pure and mixed cultures, S. cerevisiae presented a similar behaviour reaching high biomass production, completely consuming the sugar, leading to high ethanol production. Furthermore, the presence of S. cerevisiae strains in the mixed cultures promoted the production of higher alcohols, acetaldehyde and ethyl esters, whereas Kloeckera/Hanseniaspora strains stimulated the production of ethyl acetate and 2-phenyl ethyl acetate compounds.

Biotransformation of the fish waste by fermentation

African Journals Online (AJOL)

Administrator

2006-10-02

Oct 2, 2006 ... 1920, Virtanen used a sulphuric and hydrochloric acid mixture for the ... investment and by using acidifying microorganisms and molasses (source of carbon) ... The yeast was isolated from sugar-based juice. Their selection is ... agitated medium leads to a reduction of the length of fermentation to three days ...

Bioethanol production from the nutrient stress-induced microalga Chlorella vulgaris by enzymatic hydrolysis and immobilized yeast fermentation.

Science.gov (United States)

Kim, Kyoung Hyoun; Choi, In Seong; Kim, Ho Myeong; Wi, Seung Gon; Bae, Hyeun-Jong

2014-02-01

The microalga Chlorella vulgaris is a potential feedstock for bioenergy due to its rapid growth, carbon dioxide fixation efficiency, and high accumulation of lipids and carbohydrates. In particular, the carbohydrates in microalgae make them a candidate for bioethanol feedstock. In this study, nutrient stress cultivation was employed to enhance the carbohydrate content of C. vulgaris. Nitrogen limitation increased the carbohydrate content to 22.4% from the normal content of 16.0% on dry weight basis. In addition, several pretreatment methods and enzymes were investigated to increase saccharification yields. Bead-beating pretreatment increased hydrolysis by 25% compared with the processes lacking pretreatment. In the enzymatic hydrolysis process, the pectinase enzyme group was superior for releasing fermentable sugars from carbohydrates in microalgae. In particular, pectinase from Aspergillus aculeatus displayed a 79% saccharification yield after 72h at 50°C. Using continuous immobilized yeast fermentation, microalgal hydrolysate was converted into ethanol at a yield of 89%. Copyright © 2013 Elsevier Ltd. All rights reserved.

Chemical and volatile composition of jujube wines fermented by Saccharomyces cerevisiae with and without pulp contact and protease treatment

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Wenye ZHANG

2016-01-01

Full Text Available Abstract This study evaluated the chemical and volatile composition of jujube wines fermented with Saccharomyces cerevisiae A1.25 with and without pulp contact and protease treatment during fermentation. Yeast cell population, total reducing sugar and methanol contents had significant differences between nonextracted and extracted wine. The nonextracted wines had significantly higher concentrations of ethyl 9-hexadecenoate, ethyl palmitate and ethyl oleate than the extracted wines. Pulp contact also could enhance phenylethyl alcohol, furfuryl alcohol, ethyl palmitat and ethyl oleate. Furthermore, protease treatment can accelerate the release of fusel oils. The first principal component separated the wine from the extracted juice without protease from other samples based on the higher concentrations of medium-chain fatty acids and medium-chain ethyl esters. Sensory evaluation showed pulp contact and protease could improve the intensity and complexity of wine aroma due to the increase of the assimilable nitrogen.

Acetone-butyl alcohol fermentation of the cornstalk hydrolyzates prepared by the method of Riga

Energy Technology Data Exchange (ETDEWEB)

Nakhmanovich, N A; Shcheblykina, N A; Kalnina, V; Pelsis, D

1960-01-01

The possibility of use of waste instead of food products in the acetone-butyl alcohol fermentation was investigated. Crushed cornstalks hydrolyzed by the method of Riga were inverted at varying conditions. The hydrolyzate containing about 50% of reducing substances (RS), based on dry weight of cornstalks, was neutralized to pH 6.3-6.5, diluted with water to the final concentration 5.0-5.1% of RS filtered, and the filtrate sterilized. The resulting liquor (I) was mixed with the wheat meal mash containing 5% of sugar (starch calculated as glucose) and fermented. The utilization of I depended upon the regime of inversion; the optimal being 20 minutes at 115/sup 0/, hydrocoefficient 1:4. In this case the use of 40% of mash sugar in form of I did not impair the yield of fermentation. The use of corn instead of wheat meal decreased the yield of butanol and increased that of ethanol. The fermentation of the mixture of I (final concentration 3% RS) and corn gluten (final concentration 2%), mineral salts added, gave higher yields than did the fermentation of the wheat meal mash.

Enhancing cellulose accessibility of corn stover by deep eutectic solvent pretreatment for butanol fermentation.

Science.gov (United States)

Xu, Guo-Chao; Ding, Ji-Cai; Han, Rui-Zhi; Dong, Jin-Jun; Ni, Ye

2016-03-01

In this study, an effective corn stover (CS) pretreatment method was developed for biobutanol fermentation. Deep eutectic solvents (DESs), consisted of quaternary ammonium salts and hydrogen donors, display similar properties to room temperature ionic liquid. Seven DESs with different hydrogen donors were facilely synthesized. Choline chloride:formic acid (ChCl:formic acid), an acidic DES, displayed excellent performance in the pretreatment of corn stover by removal of hemicellulose and lignin as confirmed by SEM, FTIR and XRD analysis. After optimization, glucose released from pretreated CS reached 17.0 g L(-1) and yield of 99%. The CS hydrolysate was successfully utilized in butanol fermentation by Clostridium saccharobutylicum DSM 13864, achieving butanol titer of 5.63 g L(-1) with a yield of 0.17 g g(-1) total sugar and productivity of 0.12 g L(-1)h(-1). This study demonstrates DES could be used as a promising and biocompatible pretreatment method for the conversion of lignocellulosic biomass into biofuel. Copyright © 2015 Elsevier Ltd. All rights reserved.

Alkali-aided enzymatic viscosity reduction of sugar beet mash for novel bioethanol production process

International Nuclear Information System (INIS)

Srichuwong, Sathaporn; Arakane, Mitsuhiro; Fujiwara, Maki; Zhang, Zilian; Takahashi, Hiroyuki; Tokuyasu, Ken

2010-01-01

Ethanol fermentation of fresh sugar beet mash (SBM) could give a benefit on reducing energy input for sugar diffusion, juice separation, and water evaporation as used in conventional practices, thus offering promise as a low energy process. Actions of cell-wall degrading enzymes provide a mash with low viscosity, which can be easily fermented to ethanol. However, a several-fold higher enzyme loading was required for viscosity reduction of SBM compared with that of potato mash. In this study, the use of dilute alkali treatment (0.025-0.15 N NaOH, 25 o C, 1 h) in enhancing enzymatic viscosity reduction of SBM was evaluated. The results showed that higher NaOH concentration enhanced demethylation and deacetylation of SBM, resulting in greater performances of the enzymes on reducing viscosity. Efficient enzymatic viscosity reduction of SBM was observed with the 0.1 N NaOH treatment. On the other hand, untreated SBM was highly resistant to viscosity reduction, even though a 20-fold more enzyme loading was used. The resulting mash containing 12-13% (w/v) sucrose yielded 7-8% (v/v) ethanol after 24 h of fermentation (90% efficiency). Accordingly, alkali treatment can be applied for facilitating the use of fresh sugar beet for ethanol production.

Effect of fermentation inhibitors in the presence and absence of activated charcoal on the growth of Saccharomyces cerevisiae.

Science.gov (United States)

Kim, Sung-Koo; Park, Don-Hee; Song, Se Hee; Wee, Young-Jung; Jeong, Gwi-Taek

2013-06-01

The acidic hydrolysis of biomass generates numerous inhibitors of fermentation, which adversely affect cell growth and metabolism. The goal of the present study was to determine the effects of fermentation inhibitors on growth and glucose consumption by Saccharomyces cerevisiae. We also conducted in situ adsorption during cell cultivation in synthetic broth containing fermentation inhibitors. In order to evaluate the effect of in situ adsorption on cell growth, five inhibitors, namely 5-hydroxymethylfurfural, levulinic acid, furfural, formic acid, and acetic acid, were introduced into synthetic broth. The existence of fermentation inhibitors during cell culture adversely affects cell growth and sugar consumption. Furfural, formic acid, and acetic acid were the most potent inhibitors in our culture system. The in situ adsorption of inhibitors by the addition of activated charcoal to the synthetic broth increased cell growth and sugar consumption. Our results indicate that detoxification of fermentation media by in situ adsorption may be useful for enhancing biofuel production.

Study on extract dates syrup fermentation using Saccharomyces ...

African Journals Online (AJOL)

Customer

2012-04-24

Apr 24, 2012 ... conversion. A high fructose yield above 91% of the original fructose was obtained with ATCC 36858. In addition, the ethanol yield was found to be 63% of the theoretical. Key words: Saccharomyces cerevisiae, fructose, glucose, bioethanol, fermentation. INTRODUCTION. Sugars are carbohydrate materials ...

Solid state fermentation studies of citric acid production

African Journals Online (AJOL)

SERVER

2008-03-04

Mar 4, 2008 ... solid waste management, biomass energy conservation, production of high value products and little risk ... The carrier, sugarcane bagasse for solid state fermentation was procured from National Sugar Institute ... constant weight and designated as dry solid residue (DSR). The filtrate (consisting of biomass, ...

On the pull: periplasmic trapping of sugars before transport.

Science.gov (United States)

Thomas, Gavin H

2017-06-01

Bacteria have evolved many routes for taking up nutrients, demonstrating great versatility in the types and mechanism of uptake used in different physiological conditions. The discovery of a single transporter in the bacterium Advenella mimigardefordensis for the uptake of five different sugars, including L-glucose and D-xylose, is described in this issue (Meinert et al., ), providing yet another example of the surprising adaptability of bacterial transport strategies. The transporter identified is a tripartite ATP-independent (TRAP) transporter, not previously associated with sugar transport, and in fact does not transport the sugars directly at all, rather requiring them to be converted in the periplasm to their respective sugar acid forms before transport through what appears to be a novel general sugar acid transporter. In this commentary, I describe how this process is consistent with the known mechanisms of TRAP transporters and consider how the role of sugar oxidation, or oxidative fermentation, operates with multiple hexose and pentose sugars. Finally I suggest that the periplasmic conversion of nutrients acquired across the outer membrane, before transport across the inner membrane, could have potentially useful biological functions in Gram negative bacteria. © 2017 John Wiley & Sons Ltd.

Manufacture of a beverage from cheese whey using a "tea fungus" fermentation.

Science.gov (United States)

Belloso-Morales, Genette; Hernández-Sánchez, Humberto

2003-01-01

Kombucha is a sour beverage reported to have potential health effects prepared from the fermentation of black tea and sugar with a "tea fungus", a symbiotic culture of acetic acid bacteria and yeasts. Although black tea is the preferred substrate for Kombucha fermentation, other beverages have also been tested as substrates with fair results. Cheese whey is a by-product with a good amount of fermentable lactose that has been used before in the production of beverages, so the objective of this study was to test three types of whey (fresh sweet, fresh acid and reconstituted sweet) in the elaboration of a fermented beverage using a kombucha culture as inoculum. The isolation and identification of bacteria and yeasts from the fermented tea and wheys was done along with the study of the rates of change in sugar consumption, acid production and pH decrease. Several species of acetic acid bacteria (Acetobacter aceti subsp. aceti, Gluconobacter oxydans subsp. industrius, subsp. oxydans and Gluconoacetobacter xylinus) were isolated from the different kombuchas along with the yeasts Saccharomyces cerevisiae, Kluyveromyces marxianus, and Brettanomyces bruxelensis. The main metabolic products in the fermented wheys included ethanol, lactic and acetic acids. A good growth was obtained in both sweet wheys in which a pH of 3.3 and a total acid content (mainly lactic and acetic acids) of 0.07 mol/l was reached after 96 h. The sweet whey fermented beverages contained a relatively low lactose concentration (< 12 g/l). The final ethanol content was low (5 g/l) in all the fermented wheys. The whey products were strongly sour and salty non sparkling beverages.

Butyric acid fermentation from pre-treated wheat straw by a mutant clostridium tyrobutyricum strain

DEFF Research Database (Denmark)

Baroi, George Nabin; Baumann, Ivan; Westermann, Peter

Only little research on butyric acid fermentation has been carried out in relationship to bio-refinery perspectives involving strain selection, development of adapted strains, physiological analyses for higher yield, productivity and selectivity. However, a major step towards the development...... strain could grow in up to 80% pre-treated wheat straw and can ferment both glucose and xylose. The yield of butyric acid without optimization was 0,37±0,051 g butyric acid/g sugar monomers and the acetate yield was 0,06±0,021 g acetic acid/g sugar monomers. Moreover, the strain could grow without...... addition of yeast extract. Further optimization of yield and productivity is under investigation....

Fermentation of galactose when preparing alcohol from the molasses from sugar beets

Energy Technology Data Exchange (ETDEWEB)

Rosa, M

1959-01-01

A number of yeast strains (referred to by Soviet code-name only), which ferment sucrose, glucose, fructose, raffinose, and (or) melibose in beet molasses, will also ferment the galactose contained therein if they are raised first on a medium containing galactose, KH/sub 2/PO/sub 4/, (NH/sub 4/)/sub 2/SO/sub 3/, and MgSO/sub 4/ at pH 5.5. This was experimentally proved by aid of 2-dimensional paper chromatography; the chromatograms were developed at 18/sup 0/ from samples which were removed once every 24 hours from the fermentation liquor. Depending upon the strains used the galactose would disappear from the mash in 3 to 5 days. These experiments could never be continued longer than 5 days, as by that time the ethanol content of the mash was too high to allow any further assimilation of the galactose by the yeasts.

The effect on lactic fermentation of concentrating inert material with immobilised cells in a calcium alginate biocatalyser

Directory of Open Access Journals (Sweden)

Juan Carlos Serrato

2005-05-01

Full Text Available Colombia is one of the world’s main sugarcane cultivating countries but it has not diversified its fermentation industry; a few fermentation industries produce alcohol and yeasts. Lactic acid and its derivatives then become alternatives providing added value to the sugar produced, thus benefiting the regions producing the sugar.This work evaluated the kinetics of lactic acid production using immobilised cells in calcium alginate at different concentrations of inert material. Lactobacillus delbrueckiI was the microorganism used and fermentation broth mainly consisted of sucrose and yeast exact. CSTR reactors were used without pH control. The results suggested that 2% to 3% inert material in the biocatalyst increased cellular retention and diffusiveness, leading to improved conversion and reaction rate.

Solid-phase fermentation and juice expression systems for sweet sorghum

Energy Technology Data Exchange (ETDEWEB)

Bryan, W.L.; Monroe, G.E.; Caussariel, P.M.

1985-01-01

Two systems to recover fermented juice from variety M 81E sweet sorghum stalks that contained about 11% fermentable sugar were compared. (a) Stalks with leaves and tops removed were chopped and inoculated with 0.2% yeast in a forage harvester, stored under anaerobic conditions for 75 hours in insulated fermentors and pressed in a screw press to recover fermented juice (5-6% ethanol). (b) Mechanically harvested sweet sorghum billets (30 cm length) without leaves or seed heads were shredded and milled in a 3-roll mill; and bagasse was inoculated with 0.2% yeast, fermented for 100 h and pressed to recover fermented juice (4 to 5% ethanol). Potential ethanol yields were 75% of theoretical for the forage harvest system and 78% for the shredder mill system, based on 95% of theoretical ethanol yield from juice expressed during milling and no loss of ethanol during fermentation, handling and pressing in the screw press. 20 references.

Effect of sugar fatty acid esters on rumen fermentation in vitro

OpenAIRE

Wakita, M.; Hoshino, S.

1987-01-01

1.The effect of sugar fatty acid esters (SFEs; currently used as food additives for human consumption) on rumen volatile fatty acids (VFA) and gas production was studied with sheep rumen contents in vitro.2. Some SFEs having monoester contents of more than 70% increased the molar proportion of propionate in conjunction with reduction in the acetate: propionate ratio when the individual SFE was added to rumen contents in a final concentration of 4 g/l. Laurate sugar ester was the most potent p...

Production of DagA and ethanol by sequential utilization of sugars in a mixed-sugar medium simulating microalgal hydrolysate.

Science.gov (United States)

Park, Juyi; Hong, Soon-Kwang; Chang, Yong Keun

2015-09-01

A novel two-step fermentation process using a mixed-sugar medium mimicking microalgal hydrolysate has been proposed to avoid glucose repression and thus to maximize substrate utilization efficiency. When DagA, a β-agarase was produced in one step in the mixed-sugar medium by using a recombinant Streptomyces lividans, glucose was found to have negative effects on the consumption of the other sugars and DagA biosynthesis causing low substrate utilization efficiency and low DagA productivity. To overcome such difficulties, a new strategy of sequential substrate utilization was developed. In the first step, glucose was consumed by Saccharomyces cerevisiae together with galactose and mannose producing ethanol, after which DagA was produced from the remaining sugars of xylose, rhamnose and ribose. Fucose was not consumed. By adopting this two-step process, the overall substrate utilization efficiency was increased approximately 3-fold with a nearly 2-fold improvement of DagA production, let alone the additional benefit of ethanol production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Engineering sugar utilization and microbial tolerance toward lignocellulose conversion

Directory of Open Access Journals (Sweden)

Lizbeth M. Nieves

2015-02-01

Full Text Available Production of fuels and chemicals through a fermentation-based manufacturing process that uses renewable feedstock such as lignocellulosic biomass is a desirable alternative to petrochemicals. Although it is still in its infancy, synthetic biology offers great potential to overcome the challenges associated with lignocellulose conversion. In this review, we will summarize the identification and optimization of synthetic biological parts used to enhance the utilization of lignocellulose-derived sugars and to increase the biocatalyst tolerance for lignocellulose-derived fermentation inhibitors. We will also discuss the ongoing efforts and future applications of synthetic integrated biological systems used to improve lignocellulose conversion.

Biochemical and Molecular Characterization of Saccharomyces cerevisiae Strains Obtained from Sugar-Cane Juice Fermentations and Their Impact in Cachaça Production▿

Science.gov (United States)

Oliveira, Valdinéia Aparecida; Vicente, Maristela Araújo; Fietto, Luciano Gomes; de Miranda Castro, Ieso; Coutrim, Maurício Xavier; Schüller, Dorit; Alves, Henrique; Casal, Margarida; de Oliveira Santos, Juliana; Araújo, Leandro Dias; da Silva, Paulo Henrique Alves; Brandão, Rogelio Lopes

2008-01-01

Saccharomyces cerevisiae strains from different regions of Minas Gerais, Brazil, were isolated and characterized aiming at the selection of starter yeasts to be used in the production of cachaça, the Brazilian sugar cane spirit. The methodology established took into account the screening for biochemical traits desirable in a yeast cachaça producer, such as no H2S production, high tolerance to ethanol and high temperatures, high fermentative capacity, and the abilities to flocculate and to produce mycocins. Furthermore, the yeasts were exposed to drugs such as 5,5′,5"-trifluor-d,l-leucine and cerulenin to isolate those that potentially overproduce higher alcohols and esters. The utilization of a random amplified polymorphic DNA-PCR method with primers based on intron splicing sites flanking regions of the COX1 gene, as well as microsatellite analysis, was not sufficient to achieve good differentiation among selected strains. In contrast, karyotype analysis allowed a clear distinction among all strains. Two selected strains were experimentally evaluated as cachaça producers. The results suggest that the selection of strains as fermentation starters requires the combined use of biochemical and molecular criteria to ensure the isolation and identification of strains with potential characteristics to produce cachaça with a higher quality standard. PMID:18065624

Mechanism of ethanol inhibition of fermentation in Zymomonas mobilis CP4

International Nuclear Information System (INIS)

Osman, Y.A.; Ingram, L.O.

1985-01-01

Accumulation of alcohol during fermentation is accompanied by a progressive decrease in the rate of sugar conversion to ethanol. In this study, the authors provided evidence that inhibition of fermentation by ethanol can be attributed to an indirect effect of ethanol on the enzymes of glycolysis involving the plasma membrane. Ethanol decreased the effectiveness of the plasma membrane as a semipermeable barrier, allowing leakage of essential cofactors and coenzymes. This leakage of cofactors and coenzymes, coupled with possible additional leakage of intermediary metabolites en route to ethanol formation, is sufficient to explain the inhibitory effects of ethanol on fermentation in Zymomonas mobilis

Bioethanol production from Scenedesmus obliquus sugars: the influence of photobioreactors and culture conditions on biomass production.

Science.gov (United States)

Miranda, J R; Passarinho, P C; Gouveia, L

2012-10-01

A closed-loop vertical tubular photobioreactor (PBR), specially designed to operate under conditions of scarce flat land availability and irregular solar irradiance conditions, was used to study the potential of Scenedesmus obliquus biomass/sugar production. The results obtained were compared to those from an open-raceway pond and a closed-bubble column. The influence of the type of light source and the regime (natural vs artificial and continuous vs light/dark cycles) on the growth of the microalga and the extent of the sugar accumulation was studied in both PBRs. The best type of reactor studied was a closed-loop PBR illuminated with natural light/dark cycles. In all the cases, the relationship between the nitrate depletion and the sugar accumulation was observed. The microalga Scenedesmus was cultivated for 53 days in a raceway pond (4,500 L) and accumulated a maximum sugar content of 29 % g/g. It was pre-treated for carrying out ethanol fermentation assays, and the highest ethanol concentration obtained in the hydrolysate fermented by Kluyveromyces marxianus was 11.7 g/L.

Bioethanol production from Scenedesmus obliquus sugars. The influence of photobioreactors and culture conditions on biomass production

Energy Technology Data Exchange (ETDEWEB)

Miranda, J.R.; Passarinho, P.C.; Gouveia, L. [Laboratorio Nacional de Energia e Geologia (LNEG), Lisbon (Portugal). Unidade de Bioenergia

2012-10-15

A closed-loop vertical tubular photobioreactor (PBR), specially designed to operate under conditions of scarce flat land availability and irregular solar irradiance conditions, was used to study the potential of Scenedesmus obliquus biomass/sugar production. The results obtained were compared to those from an open-raceway pond and a closed-bubble column. The influence of the type of light source and the regime (natural vs artificial and continuous vs light/dark cycles) on the growth of the microalga and the extent of the sugar accumulation was studied in both PBRs. The best type of reactor studied was a closed-loop PBR illuminated with natural light/dark cycles. In all the cases, the relationship between the nitrate depletion and the sugar accumulation was observed. The microalga Scenedesmus was cultivated for 53 days in a raceway pond (4,500 L) and accumulated a maximum sugar content of 29 % g/g. It was pre-treated for carrying out ethanol fermentation assays, and the highest ethanol concentration obtained in the hydrolysate fermented by Kluyveromyces marxianus was 11.7 g/L. (orig.)

Flocculent killer yeast for ethanol fermentation of beet molasses

Energy Technology Data Exchange (ETDEWEB)

Moriya, Kazuhito; Shimoii, Hitoshi; Sato, Shun' ichi; Saito, Kazuo; Tadenuma, Makoto

1987-09-25

When ethanol is produced using beet molasses, the concentration of ethanol is lower than that obtained using suger cane molasses. Yeast strain improvement was conducted to enhance ethanol production from beet molasses. The procedures and the results are as follows: (1) After giving ethanol tolerance to the flocculent yeast, strain 180 and the killer yeast, strain 909-1, strain 180-A-7, and strain 909-1-A-4 were isolated. These ethanol tolerant strains had better alcoholic fermentation capability and had more surviving cells in mash in the later process of fermentation than the parental strains. (2) Strain H-1 was bred by spore to cell mating between these two ethanol tolerant strains. Strain H-1 is both flocculent and killer and has better alcoholic fermentation capability than the parental strains. (3) In the fermentation test of beet molasses, strain H-1 showed 12.8% of alcoholic fermentation capability. It is equal to that of sugar cane molasses. Fermentation with reused cells were also successful. (5 figs, 21 refs)

Cocoa pulp in beer production: Applicability and fermentative process performance.

Science.gov (United States)

Nunes, Cassiane da Silva Oliveira; de Carvalho, Giovani Brandão Mafra; da Silva, Marília Lordêlo Cardoso; da Silva, Gervásio Paulo; Machado, Bruna Aparecida Souza; Uetanabaro, Ana Paula Trovatti

2017-01-01

This work evaluated the effect of cocoa pulp as a malt adjunct on the parameters of fermentation for beer production on a pilot scale. For this purpose, yeast isolated from the spontaneous fermentation of cachaça (SC52), belonging to the strain bank of the State University of Feira de Santana-Ba (Brazil), and a commercial strain of ale yeast (Safale S-04 Belgium) were used. The beer produced was subjected to acceptance and purchase intention tests for sensorial analysis. At the beginning of fermentation, 30% cocoa pulp (adjunct) was added to the wort at 12°P concentration. The production of beer on a pilot scale was carried out in a bioreactor with a 100-liter capacity, a usable volume of 60 liters, a temperature of 22°C and a fermentation time of 96 hours. The fermentation parameters evaluated were consumption of fermentable sugars and production of ethanol, glycerol and esters. The beer produced using the adjunct and yeast SC52 showed better fermentation performance and better acceptance according to sensorial analysis.

Cocoa pulp in beer production: Applicability and fermentative process performance.

Directory of Open Access Journals (Sweden)

Cassiane da Silva Oliveira Nunes

Full Text Available This work evaluated the effect of cocoa pulp as a malt adjunct on the parameters of fermentation for beer production on a pilot scale. For this purpose, yeast isolated from the spontaneous fermentation of cachaça (SC52, belonging to the strain bank of the State University of Feira de Santana-Ba (Brazil, and a commercial strain of ale yeast (Safale S-04 Belgium were used. The beer produced was subjected to acceptance and purchase intention tests for sensorial analysis. At the beginning of fermentation, 30% cocoa pulp (adjunct was added to the wort at 12°P concentration. The production of beer on a pilot scale was carried out in a bioreactor with a 100-liter capacity, a usable volume of 60 liters, a temperature of 22°C and a fermentation time of 96 hours. The fermentation parameters evaluated were consumption of fermentable sugars and production of ethanol, glycerol and esters. The beer produced using the adjunct and yeast SC52 showed better fermentation performance and better acceptance according to sensorial analysis.

Stillage reflux in food waste ethanol fermentation and its by-product accumulation.

Science.gov (United States)

Ma, Hongzhi; Yang, Jian; Jia, Yan; Wang, Qunhui; Tashiro, Yukihiro; Sonomoto, Kenji

2016-06-01

Raw materials and pollution control are key issues for the ethanol fermentation industry. To address these concerns, food waste was selected as fermentation substrate, and stillage reflux was carried out in this study. Reflux was used seven times during fermentation. Corresponding ethanol and reducing sugar were detected. Accumulation of by-products, such as organic acid, sodium chloride, and glycerol, was investigated. Lactic acid was observed to accumulate up to 120g/L, and sodium chloride reached 0.14mol/L. Other by-products did not accumulate. The first five cycles of reflux increased ethanol concentration, which prolonged fermentation time. Further increases in reflux time negatively influenced ethanol fermentation. Single-factor analysis with lactic acid and sodium chloride demonstrated that both factors affected ethanol fermentation, but lactic acid induced more effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of multiple substrates in ethanol fermentations from cheese whey

Energy Technology Data Exchange (ETDEWEB)

Wang, C J; Jayanata, Y; Bajpai, R K

1987-01-01

Ethanol fermentations from cheese whey by Kluyveromyces marxianus CBS 397 were investigated. Cheese whey, which contains lactose as the major sugar, has been found to have small amounts of glucose and galactose, depending on the source and operating conditions. Fermentation performance was strongly influenced by the presence of glucose and galactose. However, lactose did not significantly affect the cell growth and product formation even at a high concentration. A logistical model was proposed to take into account the effect of lactose. (Refs. 6).

Blending municipal solid waste with corn stover for sugar production using ionic liquid process

Energy Technology Data Exchange (ETDEWEB)

Sun, Ning [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Xu, Feng [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Sathitsuksanoh, Noppadon [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Thompson, Vicki S. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Cafferty, Kara [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Li, Chenlin [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Tanjore, Deepti [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Narani, Akash [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Pray, Todd R. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Simmons, Blake A. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Singh, Seema [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

2015-06-01

Municipal solid waste (MSW) represents an attractive cellulosic resource for sustainable fuel production because of its abundance and its low or perhaps negative cost. However, the significant heterogeneity and toxic contaminants are barriers to efficient conversion to ethanol and other products. In this study, we generated MSW paper mix, blended with corn stover (CS), and have shown that both MSW paper mix alone and MSW/CS blends can be efficiently pretreated in certain ionic liquids (ILs) with high yields of fermentable sugars. After pretreatment in 1-ethyl-3-methylimidazolium acetate ([C₂C₁Im][OAc]), over 80% glucose has been released with enzymatic saccharification. We have also applied an enzyme free process by adding mineral acid and water directly into the IL/biomass slurry to induce hydrolysis. With the acidolysis process in the IL 1-ethyl-3-methylimidazolium chloride ([C₂C₁Im]Cl), up to 80% glucose and 90% xylose are released for MSW. The results indicate the feasibility of incorporating MSW as a robust blending agent for biorefineries.

Fermentative hydrogen production from pretreated biomass: A comparative study

NARCIS (Netherlands)

Panagiotopoulos, I.A.; Bakker, R.R.; Budde, M.A.W.; Vrije, de G.J.; Claassen, P.A.M.; Koukios, E.G.

2009-01-01

The aim of this work was to evaluate the potential of employing biomass resources from different origin as feedstocks for fermentative hydrogen production. Mild-acid pretreated and hydrolysed barley straw (BS) and corn stalk (CS), hydrolysed barley grains (BG) and corn grains (CG), and sugar beet

Study of continuous acetone-butanol fermentation by Clostridium acetobutylicum

Energy Technology Data Exchange (ETDEWEB)

Yarovenko, V L; Nakhmanovich, B M; Shcheblykin, N P; Senkevich, V V

1960-01-01

Prophylactic sterilization of small scale equipment (2 fermenters, 3.5 cu. m. each) permitted continuous fermentation through 6 cycles (28 days), each with a new inoculum of C. acetobutylicum. Single cycles could be prolonged to 6 to 11 days without sterilization. Contamination, usually with lactic acid bacteria, sometimes preceded exhaustion of the culture. Input of flour mash at 0.6 to 1.2 cu. m./hr. and withdrawal of products were continuous; acetone yield 6.6 to 7.1 g./l.; residual sugars 0.63 to 0.79%.

Effects of fermentation by Saccharomyces cerevisiae and ...

African Journals Online (AJOL)

yassine

2013-02-13

Feb 13, 2013 ... Full Length Research Paper. Effect of Saccharomyces cerevisiae fermentation on the ... 2003). Besides, several alcoholic beverages such as wine or liqueurs are obtained from fruit juices fermented by Saccharomyces ..... (2003). Kinetics of pigment release from hairy root cultures of Beta vulgaris under the ...

High-titer and productivity of l-(+)-lactic acid using exponential fed-batch fermentation with Bacillus coagulans arr4, a new thermotolerant bacterial strain.

Science.gov (United States)

Coelho, Luciana Fontes; Beitel, Susan Michelz; Sass, Daiane Cristina; Neto, Paulo Marcelo Avila; Contiero, Jonas

2018-04-01

Bacillus coagulans arr4 is a thermotolerant microorganism with great biotechnological potential for l-(+)-lactic acid production from granulated sugar and yeast extract. The highest l-(+)-lactic acid production was obtained with Ca(OH) 2 . The maximum production of l-(+)-lactic acid (206.81 g/L) was observed in exponential feeding using granulated sugar solution (900 g/L) and yeast extract (1%) at 50 °C, pH 6.5, and initial granulated sugar concentration of 100 g/L at 39 h. 5.3 g/L h productivity and 97% yield were observed, and no sugar remained. Comparing the simple batch with exponential fed-batch fermentation, the l(+) lactic acid production was improved in 133.22% and dry cell weight was improved in 83.29%, using granulated sugar and yeast extract. This study presents the highest productivity of lactic acid ever observed in the literature, on the fermentation of thermotolerant Bacillus sp. as well as an innovative and high-efficiency purification technology, using low-cost substances as Celite and charcoal. The recovery of lactic acid was 86%, with 100% protein removal, and the fermentation medium (brown color) became a colorless solution.

Production of lactic acid from corn cobs through fermentation lactobacillus delbruekii

International Nuclear Information System (INIS)

Ali, Z.; Anjum, M.; Zahoor, T.

2007-01-01

Corn cobs were used as the source of reducing sugars for conversion into lactic acid through fermentation by a local strain of Lactobacillus delbruekii, under varying parameters of time, temperature, pH and glucose concentration, The production of lactic acid significantly increased with increase in Ph, fermentation time and glucose concentration (1-5%) and was significantly high (8.40 g/1) at pH 6, while significantly low (7.67 g/1) at pH 5. (author)

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

Direct lactic acid fermentation of Jerusalem artichoke tuber extract using Lactobacillus paracasei without acidic or enzymatic inulin hydrolysis.

Science.gov (United States)

Choi, Hwa-Young; Ryu, Hee-Kyoung; Park, Kyung-Min; Lee, Eun Gyo; Lee, Hongweon; Kim, Seon-Won; Choi, Eui-Sung

2012-06-01

Lactic acid fermentation of Jerusalem artichoke tuber was performed with strains of Lactobacillus paracasei without acidic or enzymatic inulin hydrolysis prior to fermentation. Some strains of L. paracasei, notably KCTC13090 and KCTC13169, could ferment hot-water extract of Jerusalem artichoke tuber more efficiently compared with other Lactobacillus spp. such as L. casei type strain KCTC3109. The L. paracasei strains could utilize almost completely the fructo-oligosaccharides present in Jerusalem artichoke. Inulin-fermenting L. paracasei strains produced c.a. six times more lactic acid compared with L. casei KCTC3109. Direct lactic fermentation of Jerusalem artichoke tuber extract at 111.6g/L of sugar content with a supplement of 5 g/L of yeast extract by L. paracasei KCTC13169 in a 5L jar fermentor produced 92.5 ce:hsp sp="0.25"/>g/L of lactic acid with 16.8 g/L fructose equivalent remained unutilized in 72 h. The conversion efficiency of inulin-type sugars to lactic acid was 98% of the theoretical yield. Copyright © 2012 Elsevier Ltd. All rights reserved.

Microbial Succession And Biochemical Aspects Of Mandai Fermentation At Low Salt Concentration.

Directory of Open Access Journals (Sweden)

Hasrul Satria Nur

2009-04-01

Full Text Available Mandai isfermented food that traditionally made from the flesh of jack fruit (Arthocarphus champeden Spreg.. Usually mandai ismade as high salt concentration. However, the objective of this research is to study the succession and biochemicalaspects of microbials during fermentation at low salt concentration (10% w/v for 14 days. During the period offermentation microbial cell numbers and biochemical aspects were observed at the 3rd, 5th, 7th and 14th day. Total cellnumber of bacteria and yeast were measured by pour plate method. The measurement was also conducted on fleshbefore incubation. The biochemical aspect observation included the contents of reducing sugar, N-total, salt, and pH.The research results indicated that the pattern of microbial succession occurred the fermentation. Yeast cells grewdominantly (2.8 x 109 CFU/g on the 5th day fermentation but bacteria were dominant at the end (1.1 x 107 CFU/g. Thehighest decrease of reducing sugar and N-total contents were 0.240% at the 14th day and 0.159% at the 5th day,respectively. However, salt concentration was relatively stable and pH was varied within the range of 3.71-6.12 for thewhole period fermentation.

Methods of saccharification of polysaccharides in plants

Science.gov (United States)

Howard, John; Fake, Gina

2014-04-29

Saccharification of polysaccharides of plants is provided, where release of fermentable sugars from cellulose is obtained by adding plant tissue composition. Production of glucose is obtained without the need to add additional .beta.-glucosidase. Adding plant tissue composition to a process using a cellulose degrading composition to degrade cellulose results in an increase in the production of fermentable sugars compared to a process in which plant tissue composition is not added. Using plant tissue composition in a process using a cellulose degrading enzyme composition to degrade cellulose results in decrease in the amount of cellulose degrading enzyme composition or exogenously applied cellulase required to produce fermentable sugars.

Basis for the optimum process parameters in the fermentation of hydrolyzates and spent sulfite liquors

Energy Technology Data Exchange (ETDEWEB)

Raitseva, M K

1964-01-01

Data are presented on technical processes used in hydrolysis plants, and on the carbohydrate compound of the most typical samples of softwood hydrolyzates. The operation of the fermentation equipment and the product quality depend on the dilution factor. Data are also given on the continuous fermentation of sugar into alcohol and on its dependence on the dilution factor.

In vivo NMR study of yeast fermentative metabolism in the presence ...

Indian Academy of Sciences (India)

2011-03-14

Mar 14, 2011 ... Changes in the ion levels of nutrient media alter the intracellular ... influence the metabolic behaviour of microorganisms. We clearly have already ... during the sugar fermentation by cultures of S. cerevisiae. (Martini et al. 2004 ...

At-line monitoring of key parameters of nisin fermentation by near infrared spectroscopy, chemometric modeling and model improvement.

Science.gov (United States)

Guo, Wei-Liang; Du, Yi-Ping; Zhou, Yong-Can; Yang, Shuang; Lu, Jia-Hui; Zhao, Hong-Yu; Wang, Yao; Teng, Li-Rong

2012-03-01

An analytical procedure has been developed for at-line (fast off-line) monitoring of 4 key parameters including nisin titer (NT), the concentration of reducing sugars, cell concentration and pH during a nisin fermentation process. This procedure is based on near infrared (NIR) spectroscopy and Partial Least Squares (PLS). Samples without any preprocessing were collected at intervals of 1 h during fifteen batch of fermentations. These fermentation processes were implemented in 3 different 5 l fermentors at various conditions. NIR spectra of the samples were collected in 10 min. And then, PLS was used for modeling the relationship between NIR spectra and the key parameters which were determined by reference methods. Monte Carlo Partial Least Squares (MCPLS) was applied to identify the outliers and select the most efficacious methods for preprocessing spectra, wavelengths and the suitable number of latent variables (n (LV)). Then, the optimum models for determining NT, concentration of reducing sugars, cell concentration and pH were established. The correlation coefficients of calibration set (R (c)) were 0.8255, 0.9000, 0.9883 and 0.9581, respectively. These results demonstrated that this method can be successfully applied to at-line monitor of NT, concentration of reducing sugars, cell concentration and pH during nisin fermentation processes.

Cultivar variation and selection potential relevant to the production of cellulosic ethanol from wheat straw

DEFF Research Database (Denmark)

Lindedam, Jane; Andersen, Sven Bode; DeMartini, J.

2012-01-01

Optimizing cellulosic ethanol yield depends strongly on understanding the biological variation of feedstocks. Our objective was to study variation in capacity for producing fermentable sugars from straw of winter wheat cultivars with a high-throughput pretreatment and hydrolysis well......-plate technique. This technique enabled us to estimate cultivar-related and environmental correlations between sugar yield, chemical composition, agronomic qualities, and distribution of botanical plant parts of wheat straw cultivars. Straws from 20 cultivars were collected in duplicates on two sites in Denmark....... Following hydrothermal pretreatment (180 °C for 17.6 min) and co-hydrolysis, sugar release and sugar conversion were measured. Up to 26% difference in sugar release between cultivars was observed. Sugar release showed negative cultivar correlation with lignin and ash content, whereas sugar release showed...

BECCS potential in Brazil: Achieving negative emissions in ethanol and electricity production based on sugar cane bagasse and other residues

International Nuclear Information System (INIS)

Moreira, José Roberto; Romeiro, Viviane; Fuss, Sabine; Kraxner, Florian; Pacca, Sérgio A.

2016-01-01

Highlights: • Demonstrates the cost competitiveness of sugarcane based bioenergy carbon capture and storage (BECCS). • Evaluates BECCS based on emissions from sugar fermentation, which is the low hanging fruit technology available. • Determines the BECCS cost premium of CO_2, ethanol and electricity. • Determines the full mitigation potential of this BECCS technology in Brazil. • Discusses polices to enable BECCS deployment by society. - Abstract: Stabilization at concentrations consistent with keeping global warming below 2 °C above the pre-industrial level will require drastic cuts in Greenhouse Gas (GHG) emissions during the first half of the century; net negative emissions approaching 2100 are required in the vast majority of current emission scenarios. For negative emissions, the focus has been on bioenergy with carbon capture and storage (BECCS), where carbon-neutral bioenergy would be combined with additional carbon capture thus yielding emissions lower than zero. Different BECCS technologies are considered around the world and one option that deserves special attention applies CCS to ethanol production. It is currently possible to eliminate 27.7 million tonnes (Mt) of CO_2 emissions per year through capture and storage of CO_2 released during fermentation, which is part of sugar cane-based ethanol production in Brazil. Thus, BECCS could reduce the country’s emissions from energy production by roughly 5%. Such emissions are additional to those due to the substitution of biomass-based electricity for fossil-fueled power plants. This paper assesses the potential and cost effectiveness of negative emissions in the joint production system of ethanol and electricity based on sugar cane, bagasse, and other residues in Brazil. An important benefit is that CO_2 can be captured twice along the proposed BECCS supply chain (once during fermentation and once during electricity generation). This study only considers BECCS from fermentation because capturing

Ethanol fermentation from molasses at high temperature by thermotolerant yeast Kluyveromyces sp. IIPE453 and energy assessment for recovery.

Science.gov (United States)

Dasgupta, Diptarka; Ghosh, Prasenjit; Ghosh, Debashish; Suman, Sunil Kumar; Khan, Rashmi; Agrawal, Deepti; Adhikari, Dilip K

2014-10-01

High temperature ethanol fermentation from sugarcane molasses B using thermophilic Crabtree-positive yeast Kluyveromyces sp. IIPE453 was carried out in batch bioreactor system. Strain was found to have a maximum specific ethanol productivity of 0.688 g/g/h with 92 % theoretical ethanol yield. Aeration and initial sugar concentration were tuning parameters to regulate metabolic pathways of the strain for either cell mass or higher ethanol production during growth with an optimum sugar to cell ratio 33:1 requisite for fermentation. An assessment of ethanol recovery from fermentation broth via simulation study illustrated that distillation-based conventional recovery was significantly better in terms of energy efficiency and overall mass recovery in comparison to coupled solvent extraction-azeotropic distillation technique for the same.

Systems biology and pathway engineering enable Saccharomyces cerevisiae to utilize C-5 and C-6 sugars simultaneously for cellulosic ethanol production

Science.gov (United States)

Saccharomyces cerevisiae is a traditional industrial workhorse for ethanol production. However, conventional ethanologenic yeast is superior in fermentation of hexose sugars (C-6) such as glucose but unable to utilize pentose sugars (C-5) such as xylose richly embedded in lignocellulosic biomass. In...

Lactic acid production from wheat straw hemicellulose hydrolysate by Lactobacillus pentosus and Lactobacillus brevis

DEFF Research Database (Denmark)

Garde, Arvid; Jonsson, Gunnar Eigil; Schmidt, A. S.

2002-01-01

Lactic acid production by Lactobacillus brevis and Lactobacillus pentosus on a hemicellulose hydrolysate (HH) of wet-oxidized wheat straw was evaluated. The potential of 11-12 g/l fermentable sugars was released from the HH through either enzymatic or acidic pretreatment. Fermentation of added......% of the theoretical maximum yield after enzymatic, or acid treatment of HH, respectively. Individually, neither of the two strains were able to fully utilize the relatively broad spectra of sugars released by the acid and enzyme treatments; however, lactic acid production increased to 95% of the theoretical maximum...... yield by co-inoculation of both strains. Xylulose was the main sugar released after enzymatic treatment of HH with Celluclast(R). Lb. brevis was able to degrade xylobiose, but was unable to assimilate xylulose, whereas Lb. pentosus was able to assimilate xylulose but unable to degrade xylobiose. (C...

Effects of Lactic Acid Fermentation on the Retention of Β-Carotene Content in Orange Fleshed Sweet Potatoes

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Benard O. Oloo

2014-04-01

Full Text Available This study aimed to establish the effects of lactic fermentation on the levels of β-carotene in selected  orange fleshed sweet potato (OFSP varieties from Kenya.  Furthermore,it sought to demonstrate fermentation as a potential process for making new products from sweet potato with enhanced nutraceutical attributes. The varieties (Zapallo, Nyathiodiewo and SPK004/06 were fermented with Lactobacillus plantarum MTCC 1407 at 25 ± 2°C for 48 h and kept for 28 days to make lacto-pickles. During fermentation both analytical [pH, titratable acidity (TA, lactic acid (LA, starch, total sugar, reducing sugar (g/kg roots, texture (N/m2, β-carotene (mg/kg roots] and sensory (texture, taste, flavour and after taste attributes of sweet potato lacto-juice were evaluated. Process conditions were optimized by varying brine levels, with fermentation time. A UV-visible spectrophotometer was used to identify and quantify β-carotene. Any significant variations (p < 0.05 in analytical attributes between the fermented and unfermented samples (pH, LA, TA and β-carotene concentration of lacto-pickles, prepared from the potato roots, were assessed. The study reported a final composition of 156.49mg/kg, 0.53mg/kg, 0.3N/m2, 1.3g/kg, 5.86g/kg, 0.5g/kg and 5.86g/kg for β-carotene, Ascorbic acid, texture; Starch, total sugars, LA and TA respectively, and a pH of 3.27. The fermented products were subjected to flavour profiling by a panel. The product sensory scores were 1.5 to 2.5 on a 5 point hedonic scale, ranging from dislike slightly to like much. The products with brine levels at 4 and 6% were most preferred. The retention of β-carotene was 93.97%. This demonstrated lactic acid fermentation as a better method for processing OFSP as the main nutritional attributes are retained. The final product was resistant to spoilage microorganisms after 28 days of fermentation. Further preservation could be obtained by addition of sodium metabisulphite. In conclusion, Lactic

Fermentation process for the production of organic acids

Science.gov (United States)

Hermann, Theron; Reinhardt, James; Yu, Xiaohui; Udani, Russell; Staples, Lauren

2018-05-01

This invention relates to improvements in the fermentation process used in the production of organic acids from biological feedstock using bacterial catalysts. The improvements in the fermentation process involve providing a fermentation medium comprising an appropriate form of inorganic carbon, an appropriate amount of aeration and a biocatalyst with an enhanced ability to uptake and assimilate the inorganic carbon into the organic acids. This invention also provides, as a part of an integrated fermentation facility, a novel process for producing a solid source of inorganic carbon by sequestering carbon released from the fermentation in an alkali solution.

Pequi cake composition, hydrolysis and fermentation to bioethanol

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A. L. Macedo

2011-03-01

Full Text Available Pequizeiro (Caryocar brasiliense Camb fruits have been evaluated as a potential raw material for the newly established biodiesel industry. This scenario demands applications using the solid co-product derived from the extraction of pequi oil, called cake or meal. This study analyses the acid hydrolysis of carbohydrates present in the pequi meal in order to obtain fermentable sugars and evaluates their conversion to bioethanol. There was 27% starch in the pequi meal. The use of a CCRD experimental design type to study the acid saccharification of pequi meal results in 61.6% conversion of its starch content to reducing sugars. Positive and significant linear effects were observed for H2SO4 concentration and temperature factors, while the quadratic effect of H2SO4 concentration and the linear effect of solid-liquid ratio were negative. Even, with non-optimized fermentative condition using 1% of dried baker's yeast in conical flasks, it was possible to obtain a value equivalent to 53 L of ethanol per ton of hydrolyzed pequi meal.

Revealing the beneficial effect of protease supplementation to high gravity beer fermentations using "-omics" techniques

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Workman Chris

2011-04-01

Full Text Available Abstract Background Addition of sugar syrups to the basic wort is a popular technique to achieve higher gravity in beer fermentations, but it results in dilution of the free amino nitrogen (FAN content in the medium. The multicomponent protease enzyme Flavourzyme has beneficial effect on the brewer's yeast fermentation performance during high gravity fermentations as it increases the initial FAN value and results in higher FAN uptake, higher specific growth rate, higher ethanol yield and improved flavour profile. Results In the present study, transcriptome and metabolome analysis were used to elucidate the effect on the addition of the multicomponent protease enzyme Flavourzyme and its influence on the metabolism of the brewer's yeast strain Weihenstephan 34/70. The study underlines the importance of sufficient nitrogen availability during the course of beer fermentation. The applied metabolome and transcriptome analysis allowed mapping the effect of the wort sugar composition on the nitrogen uptake. Conclusion Both the transcriptome and the metabolome analysis revealed that there is a significantly higher impact of protease addition for maltose syrup supplemented fermentations, while addition of glucose syrup to increase the gravity in the wort resulted in increased glucose repression that lead to inhibition of amino acid uptake and hereby inhibited the effect of the protease addition.

The consequences of Lactobacillus vini and Dekkera bruxellensis as contaminants of the sugarcane-based ethanol fermentation.

Science.gov (United States)

de Souza, Rafael Barros; dos Santos, Billy Manoel; de Fátima Rodrigues de Souza, Raquel; da Silva, Paula Katharina Nogueira; Lucena, Brígida Thais Luckwu; de Morais, Marcos Antonio

2012-11-01

This work describes the effects of the presence of the yeast Dekkera bruxellensis and the bacterium Lactobacillus vini on the industrial production of ethanol from sugarcane fermentation. Both contaminants were quantified in industrial samples, and their presence was correlated to a decrease in ethanol concentration and accumulation of sugar. Then, laboratory mixed-cell fermentations were carried out to evaluate the effects of these presumed contaminants on the viability of Saccharomyces cerevisiae and the overall ethanol yield. The results showed that high residual sugar seemed the most significant factor arising from the presence of D. bruxellensis in the industrial process when compared to pure S. cerevisiae cultures. Moreover, when L. vini was added to S. cerevisiae cultures it did not appear to affect the yeast cells by any kind of antagonistic effect under stable fermentations. In addition, when L. vini was added to D. bruxellensis cultures, it showed signs of being able to stimulate the fermentative activity of the yeast cells in a way that led to an increase in the ethanol yield.

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.

Filamentous fungal diversity and community structure associated with the solid state fermentation of Chinese Maotai-flavor liquor.

Science.gov (United States)

Chen, Bi; Wu, Qun; Xu, Yan

2014-06-02

Maotai-flavor liquor is produced by simultaneous saccharification and fermentation (SSF) process under solid state conditions, including Daqu (starter) making, stacking fermentation and alcohol fermentation stages. Filamentous fungi produce many enzymes to degrade the starch material into fermentable sugar during liquor fermentation. This study investigated the filamentous fungal community associated with liquor making process. Eight and seven different fungal species were identified by using culture-dependent and -independent method (PCR-denaturing gradient gel electrophoresis, DGGE) analyses, respectively. The traditional enumeration method showed that Daqu provided 7 fungal species for stacking fermentation. The total population of filamentous fungi increased from 3.4 × 10(3)cfu/g to 1.28 × 10(4)cfu/g in the first 3 days of stacking fermentation, and then decreased till the end. In alcohol fermentation in pits, the population continuously decreased and few fungal species survived (lower than 1 × 10(3)cfu/g) after 10 days. Therefore, stacking fermentation is an essential stage for the growth of filamentous fungi. Paecilomyces variotii, Aspergillus oryzae and Aspergillus terreus were detected by both methods, and P. variotii and A. oryzae were the predominant species. Meanwhile, P. variotii possessed the highest glucoamylase (3252 ± 526 U/g) and A. oryzae exhibited the highest α-amylase (1491 ± 324 U/g) activity among the cultivable fungal species. Furthermore, the variation of starch and reducing sugar content was consistent with the growth of P. variotii and A. oryzae in Zaopei (fermented grains) during stacking fermentation, which implied that the two filamentous fungi played an important role in producing amylase for hydrolyzing the starch. Copyright © 2014 Elsevier B.V. All rights reserved.

Gamma radiation in some microbiological and biochemical parameters of ethanolic fermentation.; Efeito da radiacao gama em alguns parametros microbiologicos e bioquimicos da fermentacao alcoolica

Energy Technology Data Exchange (ETDEWEB)

Alcarde, Andre Ricardo

2000-07-01

The objective of this work was to evaluate the effect of gamma radiation in reducing the bacterial population of the sugar cane must and verify its influence in the ethanolic fermentation. For this purpose, some microbiological and biochemical parameters of the ethanolic fermentation were analyzed, such as bacterial count; viability, replication and living replicates of the yeast; p H, acidity (total and volatile), glycerol and production of organic acids (acetic, lactic and succinic) during the fermentation; and fermentative yield. Bacteria of the genera Bacillus and Lactobacillus are the most common contaminants of the ethanolic fermentation and they might cause a decrease in the fermentative yield. The ionizing radiations may affect the microorganisms altering the DNA of the cells, which lose the ability to reproduce themselves and die. The experimental design was in randomized blocks (three) with one replicate in each block. The must was sugar-cane juice with approximately 5% of total reducing sugar. Bacteria of the following species were tested: Bacillus subtilis, Bacillus coagulans, Lactobacillus plantarum and Lactobacillus fermentum. The experiments were the inoculation of each bacteria separately in the must, the inoculation of the mixture of the four bacteria in the must and the use of natural sugar-cane juice with its own contaminating microorganisms. The contaminated must was irradiated with the doses of 0.0 (control), 2.0,4.0, 6.0, 8.0 and 10.0 kGy of gamma radiation (60-Cobalt) at an average rate of 2.0 kGy/h. After the irradiation, the fermentation of the must was carried out using the yeast Saccharomyces cerevisiae (Fleischmann). It was also accomplished an experiment with the inoculation of the mixture of the four bacteria in the must and, instead of using gamma radiation to decontaminate the must, it was used the antimicrobial Kamoran ID in the concentration of 3 ppm. The effects of the irradiation of the must were: reduction of the bacterial

Comparative study of physicochemical analysis of prosopis africana seeds fermented with different starter cultures

Directory of Open Access Journals (Sweden)

G. P. Oyeyiola

2017-01-01

Full Text Available Prosopis africana (African mesquite is one of the lesser known legume seed crops in Nigeria, which in a fermented state, gives a food condiment. Because of its rich protein content (about 34%, efforts are made to utilize some lesser known legumes to improve the nutritional status of the people. This study was carried out by fermenting Prosopis africana seeds with mono and mixed cultures of bacterial isolates to produce a local condiment called Okpehe. Standard AOAC methods were used to determine the pH, total sugar and crude protein content of the fermented seeds. During the production of Okpehe with mono cultures of bacteria, the pH ranged between 6.80 and 8.92; total sugar between 10.2 and 7.5 mg/g, and crude protein between 34.62 and 41.25%. In the mixed culture inoculated samples, the pH increased from 7.00 to 8.92; total sugar decreased from 9.4 to 7.4 mg/g, while the crude protein increased (35.02 - 44.61% significantly (p < 0.05 as the fermentation progressed. The highest crude protein content of 44.61% was obtained with the combination of Bacillus subtilis and Bacillus licheniformis, while the lowest protein content referred to the combination of Bacillus megaterium and Bacillus pumilus. The result of this study showed that Prosopis africana seeds could be utilized for the production of Okpehe using mixed cultures of B. subtilis and B. licheniformis, so as to increase the protein intake of the populace.

Hydrogen gas production by fermentation from various organic wastewater using Clostridium butyricum NCIB 9576 and Rhodopseudomonas sphaeroides E15-1

Energy Technology Data Exchange (ETDEWEB)

Yoon, Young Sue; Kim, Hyun Kyung; Rye, Hye Yeon; Lee, In Gu; Kim, Mi Sun [Biomass Research Team, Korea Institute of Energy Research, Taejeon (Korea)

2000-03-01

Anaerobic fermentation using Clostidium butyricum NCIB 9576, and phto-fermentation using Rhodopseudomonas sphaeroides E15-1 were studied for the production of hydrogen from Makkoli, fruits (orange and apple, watermelon and melon) and Tofu wastewaters. From the Makkoli wastewater, which contained 0.94 g/liter sugars and 2.74 g/liter solubel starch, approximately 49 mM H{sub 2}/liter wastewater was produced during the initial 18h of the anaerobic fermentation with pH control between 6.5-7.0. Several organic acids such as butyric acid, acetic acid, propionic acid, lactic acid and ethanol were also produced. From watermelon and melon wastewater, which contained 43 g/liter sugars, generated about approximately 71 mM H{sub 2}/liter wastewater was produced during the initial 24h of the anaerobic fermentation. Tofu wastewater, pH 6.5, containing 12.6 g/liter soluble starch and 0.74 g/liter sugars, generated about 30mM H{sub 2}/liter wastewater, along with some organic acids, during the initial 24 h of anaerobic fermentation. Makkoli and Tofu wastewaters as substrates for the photo-fermentation by Rhodopseudomonas sphaeroides E15-1 produced approximately 37.9 and 22.2 {mu}M H{sub 2}/ml wastewaters, respectively for 9 days of incubation under the average of 9,000010,000 lux illumination at the surface of reactor using tungsten halogen lamps. Orange and apple wastewater, which contained 93.4 g/l produced approximately 13.1 {mu}M H{sub 2}/ml wastewater only for 2 days of photo-fermentation and the growth of Rhodopseudomonas spnaeroides E15-1 and hydrogen production were stopped. 22 refs, 4 figs., 2 tabs.

Comparative genomics of xylose-fermenting fungi for enhanced biofuel production

Science.gov (United States)

Dana J. Wolbach; Alan Kuo; Trey K. Sato; Katlyn M. Potts; Asaf A. Salamov; Kurt M. LaButti; Hui Sun; Alicia Clum; Jasmyn L. Pangilinan; Erika A. Lindquist; Susan Lucas; Alla Lapidus; Mingjie Jin; Christa Gunawan; Venkatesh Balan; Bruce E. Dale; Thomas W. Jeffries; Robert Zinkel; Kerrie W. Barry; Igor V. Grigoriev; Audrey P. Gasch

2011-01-01

Cellulosic biomass is an abundant and underused substrate for biofuel production. The inability of many microbes to metabolize the pentose sugars abundant within hemicellulose creates specific challenges for microbial biofuel production from cellulosic material. Although engineered strains of Saccharomyces cerevisiae can use the pentose xylose, the fermentative...

Solid state fermentation for production of microbial cellulases: Recent advances and improvement strategies.

Science.gov (United States)

Behera, Sudhanshu S; Ray, Ramesh C

2016-05-01

Lignocellulose is the most plentiful non-food biomass and one of the most inexhaustible renewable resources on the planet, which is an alternative sustainable energy source for the production of second generation biofuels. Lignocelluloses are composed of cellulose, hemicellulose and lignin, in which the sugar polymers account for a large portion of the biomass. Cellulases belong to the glycoside hydrolase family and catalyze the hydrolysis of glyosidic linkages depolymerizing cellulose to fermentable sugars. They are multi-enzymatic complex proteins and require the synergistic action of three key enzymes: endoglucanase (E.C. 3.2.1.4), exoglucanase (E.C. 3.2.1.176) (E.C. 3.2.1.91) and β-glucosidase (E.C. 3.2.1.21) for the depolymerization of cellulose to glucose. Solid state fermentation, which holds growth of microorganisms on moist solid substrates in the absence of free flowing water, has gained considerable attention of late due its several advantages over submerged fermentation. The review summarizes the critical analysis of recent literature covering production of cellulase in solid state fermentation using advance technologies such as consolidated bioprocessing, metabolic engineering and strain improvement, and circumscribes the strategies to improve the enzyme yield. Copyright © 2016. Published by Elsevier B.V.

Amino acid and fatty acid compositions of Rusip from fermented Anchovy fish (Stolephorussp)

Science.gov (United States)

Koesoemawardani, D.; Hidayati, S.; Subeki

2018-04-01

Rusip is a typical food of Bangka Belitung Indonesia made from fermented anchovy. This study aims to determine the properties of chemistry, microbiology, composition of amino acids and fatty acids from fermented fish spontaneously and non spontaneously. Spontaneous rusip treatment is done by anchovy fish (Stolephorussp) after cleaning and added salt 25% (w/w) and palm sugar 10% (w/w). While, non-spontaneous rusip is done by adding a culture mixture of Streptococcus, Leuconostoc, and Lactobacillus bacteria 2% (w/v). The materials are then incubated for 2 weeks. The data obtained were then performed t-test at the level of 5%. Spontaneous and non-spontaneous rusip fermentation process showed significant differences in total acid, reducing sugar, salt content, TVN, total lactic acid bacteria, total mold, and total microbial. The dominant amino acid content of spontaneous and non-spontaneous rusip are glutamic acid and aspartic acid, while the dominant fatty acids in spontaneous and non-spontaneous rusip are docosahexaenoic acid, palmitic acid, oleic acid, arachidonic acid, stearic acid, eicosapentaenoic acid, palmitoleic acid, and myristic acid.

Pentose sugars inhibit metabolism and increase expression of an AgrD-type cyclic pentapeptide in Clostridium thermocellum.

Science.gov (United States)

Verbeke, Tobin J; Giannone, Richard J; Klingeman, Dawn M; Engle, Nancy L; Rydzak, Thomas; Guss, Adam M; Tschaplinski, Timothy J; Brown, Steven D; Hettich, Robert L; Elkins, James G

2017-02-23

Clostridium thermocellum could potentially be used as a microbial biocatalyst to produce renewable fuels directly from lignocellulosic biomass due to its ability to rapidly solubilize plant cell walls. While the organism readily ferments sugars derived from cellulose, pentose sugars from xylan are not metabolized. Here, we show that non-fermentable pentoses inhibit growth and end-product formation during fermentation of cellulose-derived sugars. Metabolomic experiments confirmed that xylose is transported intracellularly and reduced to the dead-end metabolite xylitol. Comparative RNA-seq analysis of xylose-inhibited cultures revealed several up-regulated genes potentially involved in pentose transport and metabolism, which were targeted for disruption. Deletion of the ATP-dependent transporter, CbpD partially alleviated xylose inhibition. A putative xylitol dehydrogenase, encoded by Clo1313_0076, was also deleted resulting in decreased total xylitol production and yield by 41% and 46%, respectively. Finally, xylose-induced inhibition corresponds with the up-regulation and biogenesis of a cyclical AgrD-type, pentapeptide. Medium supplementation with the mature cyclical pentapeptide also inhibits bacterial growth. Together, these findings provide new foundational insights needed for engineering improved pentose utilizing strains of C. thermocellum and reveal the first functional Agr-type cyclic peptide to be produced by a thermophilic member of the Firmicutes.

Use of Gelidium amansii as a promising resource for bioethanol: a practical approach for continuous dilute-acid hydrolysis and fermentation.

Science.gov (United States)

Park, Jeong-Hoon; Hong, Ji-Yeon; Jang, Hyun Chul; Oh, Seung Geun; Kim, Sang-Hyoun; Yoon, Jeong-Jun; Kim, Yong Jin

2012-03-01

A facile continuous method for dilute-acid hydrolysis of the representative red seaweed species, Gelidium amansii was developed and its hydrolysate was subsequently evaluated for fermentability. In the hydrolysis step, the hydrolysates obtained from a batch reactor and a continuous reactor were systematically compared based on fermentable sugar yield and inhibitor formation. There are many advantages to the continuous hydrolysis process. For example, the low melting point of the agar component in G. amansii facilitates improved raw material fluidity in the continuous reactor. In addition, the hydrolysate obtained from the continuous process delivered a high sugar and low inhibitor concentration, thereby leading to both high yield and high final ethanol titer in the fermentation process. Copyright © 2011 Elsevier Ltd. All rights reserved.

Nonnutritive, Low Caloric Substitutes for Food Sugars: Clinical Implications for Addressing the Incidence of Dental Caries and Overweight/Obesity

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Michael W. Roberts

2012-01-01

Full Text Available Caries and obesity are two common conditions affecting children in the United States and other developed countries. Caries in the teeth of susceptible children have often been associated with frequent ingestion of fermentable sugars such as sucrose, fructose, glucose, and maltose. Increased calorie intake associated with sugars and carbohydrates, especially when associated with physical inactivity, has been implicated in childhood obesity. Fortunately, nonnutritive artificial alternatives and non-/low-caloric natural sugars have been developed as alternatives to fermentable sugars and have shown promise in partially addressing these health issues. Diet counseling is an important adjunct to oral health instruction. Although there are only five artificial sweeteners that have been approved as food additives by the Food and Drug Administration (FDA, there are additional five non-/low caloric sweeteners that have FDA GRAS (Generally Recognized as Safe designation. Given the health impact of sugars and other carbohydrates, dental professionals should be aware of the nonnutritive non-/low caloric sweeteners available on the market and both their benefits and potential risks. Dental health professionals should also be proactive in helping identify patients at risk for obesity and provide counseling and referral when appropriate.

Effect of agitation rate on ethanol production from sugar maple hemicellulosic hydrolysate by Pichia stipitis.

Science.gov (United States)

Shupe, Alan M; Liu, Shijie

2012-09-01

Concentrated dilute acid hydrolysate was obtained from hot water extracts of Acer saccharum (sugar maple) and was fermented to ethanol by Pichia stipitis in a 1.3-L-benchtop bioreactor. The conditions under which the highest ethanol yield was achieved were when the air flow rate was set to 100 cm(3) and the agitation rate was set to 150 rpm resulting in an overall mass transfer coefficient (K(L)a) of 0.108 min(-1). A maximum ethanol concentration of 29.7 g/L was achieved after 120 h of fermentation; however, after 90 h of fermentation, the ethanol concentration was only slightly lower at 29.1 g/L with a yield of 0.39 g ethanol per gram of sugar consumed. Using the same air flow rate and adjusting the agitation rate resulted in lower ethanol yields of 0.25 g/g at 50 rpm and 0.30 g/g at 300 rpm. The time it takes to reach the maximum ethanol concentration was also affected by the agitation rate. The ethanol concentration continued to increase even after 130 h of fermentation when the agitation rate was set at 50 rpm, whereas the maximum ethanol concentration was reached after only 68.5 h at 300 rpm.

Effect of hemicellulolytic enzymes on mesophilic methane fermentation

Energy Technology Data Exchange (ETDEWEB)

Oi, S; Matsui, Y; Iizuka, M; Yamamoto, T

1977-01-01

Mesophilic methane fermentation was examined using soybean seed coat, a waste from soybean processing for oil manufacture, with or without treatment with hemicellulolytic enzymes of Aspergillus niger, and the following results were obtained: (1) The methane fermentation bacteria acclimated to soybean seed coat medium were shown to consume monosaccharides and evolve methane in the following decreasing order: glucose, fructose, mannose > xylose, galactose, glucosamine, galacturonic acid > arabinose. The bacteria were also shown to form methane from a gas mixture of hydrogen and carbon dioxide. (2) In fermentation of soybean seed coat treated with the fungal enzyme, about 70% of the total sugar content as consumed in four weeks, and the gas evolution was about twice that without the fungal enzyme. The gas evolved was composed of 60% methane and 36% carbon dioxide. In general, vigorous evolution of hydrogen and carbon dioxide occurred at a very early stage of fermentation, and was followed by formation of methane. The maximum gas evolution of the enzyme-treated mash took place in 6 days while that of untreated mash occurred one week later. Chemical oxygen demand of the supernatant of the former mash was decreased by fermentation to 7.0% of the initial level.

The interactive effect of fungicide residues and yeast assimilable nitrogen on fermentation kinetics and hydrogen sulfide production during cider fermentation.

Science.gov (United States)

Boudreau, Thomas F; Peck, Gregory M; O'Keefe, Sean F; Stewart, Amanda C

2017-01-01

Fungicide residues on fruit may adversely affect yeast during cider fermentation, leading to sluggish or stuck fermentation or the production of hydrogen sulfide (H 2 S), which is an undesirable aroma compound. This phenomenon has been studied in grape fermentation but not in apple fermentation. Low nitrogen availability, which is characteristic of apples, may further exacerbate the effects of fungicides on yeast during fermentation. The present study explored the effects of three fungicides: elemental sulfur (S 0 ) (known to result in increased H 2 S in wine); fenbuconazole (used in orchards but not vineyards); and fludioxonil (used in post-harvest storage of apples). Only S 0 led to increased H 2 S production. Fenbuconazole (≥0.2 mg L -1 ) resulted in a decreased fermentation rate and increased residual sugar. An interactive effect of yeast assimilable nitrogen (YAN) concentration and fenbuconazole was observed such that increasing the YAN concentration alleviated the negative effects of fenbuconazole on fermentation kinetics. Cidermakers should be aware that residual fenbuconazole (as low as 0.2 mg L -1 ) in apple juice may lead to stuck fermentation, especially when the YAN concentration is below 250 mg L -1 . These results indicate that fermentation problems attributed to low YAN may be caused or exacerbated by additional factors such as fungicide residues, which have a greater impact on fermentation performance under low YAN conditions. © 2016 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2016 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

LCA of 1,4-Butanediol Produced via Direct Fermentation of Sugars from Wheat Straw Feedstock within a Territorial Biorefinery

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Annachiara Forte

2016-07-01

Full Text Available The bio-based industrial sector has been recognized by the European Union as a priority area toward sustainability, however, the environmental profile of bio-based products needs to be further addressed. This study investigated, through the Life Cycle Assessment (LCA approach, the environmental performance of bio-based 1,4-butanediol (BDO produced via direct fermentation of sugars from wheat straw, within a hypothetical regional biorefinery (Campania Region, Southern Italy. The aim was: (i to identify the hotspots along the production chain; and (ii to assess the potential environmental benefits of this bio-based polymer versus the reference conventional product (fossil-based BDO. Results identified the prevailing contribution to the total environmental load of bio-based BDO in the feedstock production and in the heat requirement at the biorefinery plant. The modeled industrial bio-based BDO supply chain, showed a general reduction of the environmental impacts compared to the fossil-based BDO. The lowest benefits were gained in terms of acidification and eutrophication, due to the environmental load of the crop phase for feedstock cultivation.

High efficient ethanol and VFAs production from gas fermentation: effect of acetate, gas and inoculum microbial composition

DEFF Research Database (Denmark)

El-Gammal, Maie; Abou-Shanab, Reda; Angelidaki, Irini

2017-01-01

In bioindustry, syngas fermentation is a promising technology for biofuel production without the use of plant biomass as sugar-based feedstock. The aim of this study was to identify optimal conditions for high efficient ethanol and volatile fatty acids (VFA) production from synthetic gas fermenta......In bioindustry, syngas fermentation is a promising technology for biofuel production without the use of plant biomass as sugar-based feedstock. The aim of this study was to identify optimal conditions for high efficient ethanol and volatile fatty acids (VFA) production from synthetic gas...... fatty acids and ethanol was achieved by the pure culture (Clostridium ragsdalei). Depending on the headspace gas composition, VFA concentrations were up to 300% higher after fermentation with Clostridium ragsdalei compared to fermentation with mixed culture. The preferred gas composition with respect...... to highest VFA concentration was pure CO (100%) regardless of microbial composition of the inoculum and media composition. The addition of acetate had a negative impact on the VFA formation which was depending on the initial gas composition in head space....

Sugar cane/sweet sorghum as an ethanol feedstock in Louisiana and Piedmont

International Nuclear Information System (INIS)

Marsh, L.S.; Cundiff, J.S.

1991-01-01

Cost to provide readily fermentable feedstock for a year round sweet sorghum-to-ethanol production facility, up to the point at which fermentation begins, was determined. It was assumed that sweet sorghum is produced on marginal crop lands in the Southeastern Piedmont, and is purchased, standing in the field by a central ethanol production facility. Feedstock cost varied from $1.96 to $2.98/gal of ethanol potential depending on harvest system and use of by-products. Major contributors to feedstock cost were field production, harvest/field processing, and cost to evaporate juice to a storable syrup. Cost to transport feedstock to a central production facility, and cost of storage were relatively minor components of total cost, contributing only $0.05 and $0.06/gal ethanol potential, respectively. For a point of comparison, cost of producing ethanol feedstock from sugar cane, based on current processing practices in Louisiana sugar mills, was determined to be $2.50/gal ethanol potential. This cost is higher than determined for most options in the Piedmont for two reasons: (1) sugar cane demands a higher price in Louisiana than was assumed for sweet sorghum in the Piedmont, and (2) little market exists in Louisiana for by-products of sugar milling, consequently, no by-product credit was assigned. Current market value of ethanol must approximately double before a sweet sorghum-to-ethanol industry in the Piedmont could be economically viable, as no opportunity was identified for a significant reduction in feedstock cost

Yeast hulls: effect on spontaneous fermentation in different vinification conditions

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Rosa López

2000-09-01

Full Text Available The effect of the addition of yeast hulls in vinification was investigated during three consecutive years. The study was carried out in the experimental winery of C.I.D.A in La Rioja (Spain with free running white grape juice of the Viura variety. Four different vinifications were studied. In two of these vinifications, stuck fermentations were detected. In all the studies, the addition of yeast hulls (yeast ghosts improved the fermentation kinetics, increasing the number of viable yeasts at the end of the exponential stage and decreasing the final content of reducing sugars. This work revealed a new effect of yeast hull addition which had not been identified previously; their selection effect on the wild yeast strain in spontaneous fermentation.

Introducing capnophilic lactic fermentation in a combined dark-photo fermentation process: a route to unparalleled H2 yields.

Science.gov (United States)

Dipasquale, L; Adessi, A; d'Ippolito, G; Rossi, F; Fontana, A; De Philippis, R

2015-01-01

Two-stage process based on photofermentation of dark fermentation effluents is widely recognized as the most effective method for biological production of hydrogen from organic substrates. Recently, it was described an alternative mechanism, named capnophilic lactic fermentation, for sugar fermentation by the hyperthermophilic bacterium Thermotoga neapolitana in CO2-rich atmosphere. Here, we report the first application of this novel process to two-stage biological production of hydrogen. The microbial system based on T. neapolitana DSM 4359(T) and Rhodopseudomonas palustris 42OL gave 9.4 mol of hydrogen per mole of glucose consumed during the anaerobic process, which is the best production yield so far reported for conventional two-stage batch cultivations. The improvement of hydrogen yield correlates with the increase in lactic production during capnophilic lactic fermentation and takes also advantage of the introduction of original conditions for culturing both microorganisms in minimal media based on diluted sea water. The use of CO2 during the first step of the combined process establishes a novel strategy for biohydrogen technology. Moreover, this study opens the way to cost reduction and use of salt-rich waste as feedstock.

Amylolysis of raw corn by Aspergillus niger for simultaneous ethanol fermentation

Energy Technology Data Exchange (ETDEWEB)

Han, I.Y.; Steinberg, M.P.

1987-01-01

The novelty of this approach was hydrolysis of the raw starch in ground corn to fermentable sugars that are simultaneously fermented to ethanol by yeast in a nonsterile environment. Thus, the conventional cooking step can be eliminated for energy conservation. A koji of Aspergillus niger grown on whole corn for 3 days was the crude enzyme source. A ratio of 0.2 g dry koji/g total solids was found sufficient. Optimum pH was 4.2. Ethanol concentration was 7.7% (w/w) in the aqueous phase with 92% raw starch conversion. Agitation increased rate. Sacharification was the rate-limiting step. The initial ethanol concentration preventing fermentation was estimated to be 8.3% by weight. (Refs. 96).

Industrial optimization of acetone-butanol fermentation: A study of the utilization of Jerusalem artichokes

Energy Technology Data Exchange (ETDEWEB)

Marchal, R.; Blanchet, D.; Vandecasteele, J.P.

1985-12-01

Acetone-butanol fermentation of the Jerusalem artichoke has been studied as a case for systematic investigation of the industrial optimization of both strain selection and fermentation operation. Hydrolysis of the inulinic oligofructans of the substrate was found necessary for optimal performance but could be achieved with a selected strain using a moderate amount of inulinase added at the beginning of the fermentation. Apart from ammonia, no nutritrional supplementation of the medium was found necessary. The marked influence of pH in the fermentation performance prompted a detailed search for a method of controlling pH during fermentation. With an optimized procedure, solvent production of 23-24 g/l were obtained in 36 h. Detailed fermentation balances are presented. An industrial process for ABE production from Jerusalem artichoke or sugar beet has been defined and tested in the pilot plant. (orig.).

Development of an integrated pretreatment fractionation process for fermentable sugars and lignin: Application to almond (Prunus dulcis) shell

International Nuclear Information System (INIS)

Gong, Dachun; Holtman, Kevin M.; Franqui-Espiet, Diana; Orts, William J.; Zhao, Ruming

2011-01-01

An environmentally friendly pretreatment process was developed to fractionate cellulose, hemicellulose and lignin from almond (Prunus dulcis) shells, consisting of hot water pretreatment (HWP) coupled with organic solvent (organosolv) pretreatment of water/ethanol (OWEP). This integrated pretreatment process proved more effective on the basis of yield of fermentable sugar and lignin separation compared with HWP alone, dilute acid pretreatment (DAP), ammonia pretreatment (AP), lime pretreatment LP, organosolv water/ethanol pretreatment (OWEP), and organosolv water/acetone pretreatment (OWAP). In the coupled hot water-organosolv process, hemicellulose sugars were recovered in the first residual liquid while varying amounts of cellulose was retained in the residual solid. The lignin fraction was obtained by simply adjusting the pH from the second liquid. The optimal two-stage process consisted of first HWP stage at 195 o C for 30 min, resulting in w glucose = 95.4% glucose recovery yield and w xylose = 92.2% xylose removal. The second organosolv OWEP stage was operated at 195 o C for 20 min, in ethanol in water mixtures of ethanol = 50% and resulted in nearly w glucose = 100% glucose recovery yield, w xylose = 90% xylose and w lignin = 61% lignin removal. After enzymatic hydrolysis, glucose yield was up to w glucose = 95%, compared to 61% yield from untreated almond. Images obtained via scanning electron microscopy (SEM) highlighted the differences in almond structure from the varying pretreatment methods during biomass fractionation. -- Highlights: → Almond shells are an under-utilized agriculture byproduct available in the world. → Almond shells are particularly attractive as bioenergy feedstock. → We have developed a new fractionation process for the almond shell. → The new process combined the HWP with OWEP. → The fractionation process has potential in the utilization of almond shell.

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. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Enzymatic conversion of pretreated biomass into fermentable sugars for biorefinery operation

Science.gov (United States)

Gao, Dahai

2011-12-01

Depleting petroleum reserves and potential climate change caused by fossil fuel consumption have attracted significant attention towards the use of alternative renewable resources for production of fuels and chemicals. Lignocellulosic biomass provides a plentiful resource for the sustainable production of biofuels and biochemicals and could serve as an important contributor to the world energy portfolio in the near future. Successful biological conversion of lignocellulosic biomass requires an efficient and economical pretreatment method, high glucose/xylose yields during enzymatic hydrolysis and fermentation of both hexose and pentose to ethanol. High enzyme loading is a major economic bottleneck for the commercial processing of pretreated lignocellulosic biomass to produce fermentable sugars. Optimizing the enzyme cocktail for specific types of pretreated biomass allows for a significant reduction in enzyme loading without sacrificing hydrolysis yield. Core glycosyl hydrolases were isolated and purified from various sources to help rationally optimize an enzyme cocktail to digest ammonia fiber expansion (AFEX) treated corn stover. The four core cellulases were endoglucanase I (EG I), cellobiohydrolase I (CBH I), cellobiohydrolase II (CBH II) and beta-Glucosidase (betaG). The two core hemicellulases were an endoxylanase (EX) and a beta-xylosidase (betaX). A diverse set of accessory hemicellulases from bacterial sources was found necessary to enhance the synergistic action of cellulases hydrolysing AFEX pretreated corn stover. High glucose (around 80%) and xylose (around 70%) yields were achieved with a moderate enzyme loading (˜20 mg protein/g glucan) using an in-house developed enzyme cocktail and this cocktail was compared to commercial enzyme. Studying the binding properties of cellulases to lignocellulosic substrates is critical to achieving a fundamental understanding of plant cell wall saccharification. Lignin auto-fluorescence and degradation products

Effective method of fermentation of Riga hydrolyzates of corn cobs and other vegetable waste products for butanol and acetone

Energy Technology Data Exchange (ETDEWEB)

Nakhmanovich, B M; Kameneva, L; Kalnina, V

1963-01-01

A simplified method is described for the production of butanol and acetone. The acid mixture (H/sub 3/PO/sub 4/, 10 to 20%; H/sub 2/SO/sub 4/, 90 to 80%) used to hydrolyze corn cobs and other vegetable waste products served also to invert the sugar of molasses which was added in 3 parts to 1 part hydrolyzate on the basis of reducing sugar content. The mixture was then diluted and neutralized with NH/sub 4/OH to pH 6.3 to 6.8. In this way a suitable hydrolyzate medium containing the appropriate amounts of mineral salts as well as invert sugar was provided for fermentation by Clostridium butyricum Prazmowsky. Lignin which precipitated during hydrolysis served as a solid phase which helped to accelerate fermentation. Combined yields of butanol, acetone, and small amounts of ethanol amounted to 30 to 38% of the available sugar; approximately 67% consisted of butanol.

Effect of biofilm formation by Oenococcus oeni on malolactic fermentation and the release of aromatic compounds in wine

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Alexandre eBastard

2016-04-01

Full Text Available The winemaking process involves the alcoholic fermentation of must, often followed by malolactic fermentation. The latter, mainly carried out by the lactic acid bacterium Oenococcus oeni, is used to improve wine quality when acidity reduction is required. Moreover, it prevents microbial spoilage and improves the wine’s organoleptic profile. Prior observations showed that O. oeni is able to resist several months in harsh wine conditions when adhered on oak barrels. Since biofilm is a prevailing microbial lifestyle in natural environments, the capacity of O. oeni to form biofilms was investigated on winemaking material such as stainless steel and oak chips. Scanning Electron Microscopy and Confocal Laser Scanning Microscopy showed that O. oeni was able to adhere to these surfaces and form spatially organized microcolonies embedded in extracellular substances. To assess the competitive advantage of this mode of life in wine, the properties of biofilm and planktonic cells were compared after inoculation in a fermented must (pH 3.5 or 3.2 and 12% ethanol The results indicated that the biofilm culture of O. oeni conferred (i increased tolerance to wine stress, and (ii functional performance with effective malolactic activities. Relative gene expression focusing on stress genes and genes involved in EPS synthesis was investigated in a mature biofilm and emphasized the role of the matrix in increased biofilm resistance.As oak is commonly used in wine aging, we focused on the O. oeni biofilm on this material and its contribution to the development of wine color and the release of aromatic compounds. Analytical chromatography was used to target the main oak aging compounds such as vanillin, gaiacol, eugenol, whisky-lactones and furfural. The results reveal that O. oeni biofilm developed on oak can modulate the wood-wine transfer of volatile aromatic compounds during malolactic fermentation and aging by decreasing furfural, gaiacol and eugenol in

Fermentative production of isobutene.

Science.gov (United States)

van Leeuwen, Bianca N M; van der Wulp, Albertus M; Duijnstee, Isabelle; van Maris, Antonius J A; Straathof, Adrie J J

2012-02-01

Isobutene (2-methylpropene) is one of those chemicals for which bio-based production might replace the petrochemical production in the future. Currently, more than 10 million metric tons of isobutene are produced on a yearly basis. Even though bio-based production might also be achieved through chemocatalytic or thermochemical methods, this review focuses on fermentative routes from sugars. Although biological isobutene formation is known since the 1970s, extensive metabolic engineering is required to achieve economically viable yields and productivities. Two recent metabolic engineering developments may enable anaerobic production close to the theoretical stoichiometry of 1isobutene + 2CO(2) + 2H(2)O per mol of glucose. One relies on the conversion of 3-hydroxyisovalerate to isobutene as a side activity of mevalonate diphosphate decarboxylase and the other on isobutanol dehydration as a side activity of engineered oleate hydratase. The latter resembles the fermentative production of isobutanol followed by isobutanol recovery and chemocatalytic dehydration. The advantage of a completely biological route is that not isobutanol, but instead gaseous isobutene is recovered from the fermenter together with CO(2). The low aqueous solubility of isobutene might also minimize product toxicity to the microorganisms. Although developments are at their infancy, the potential of a large scale fermentative isobutene production process is assessed. The production costs estimate is 0.9 Euro kg(-1), which is reasonably competitive. About 70% of the production costs will be due to the costs of lignocellulose hydrolysate, which seems to be a preferred feedstock.

Changes in free-radical scavenging ability of kombucha tea during fermentation.

Science.gov (United States)

Jayabalan, R; Subathradevi, P; Marimuthu, S; Sathishkumar, M; Swaminathan, K

2008-07-01

Kombucha tea is a fermented tea beverage produced by fermenting sugared black tea with tea fungus (kombucha). Free-radical scavenging abilities of kombucha tea prepared from green tea (GTK), black tea (BTK) and tea waste material (TWK) along with pH, phenolic compounds and reducing power were investigated during fermentation period. Phenolic compounds, scavenging activity on DPPH radical, superoxide radical (xanthine-xanthine oxidase system) and inhibitory activity against hydroxyl radical mediated linoleic acid oxidation (ammonium thiocyanate assay) were increased during fermentation period, whereas pH, reducing power, hydroxyl radical scavenging ability (ascorbic acid-iron EDTA) and anti-lipid peroxidation ability (thiobarbituric assay) were decreased. From the present study, it is obvious that there might be some chances of structural modification of components in tea due to enzymes liberated by bacteria and yeast during kombucha fermentation which results in better scavenging performance on nitrogen and superoxide radicals, and poor scavenging performance on hydroxyl radicals. Copyright © 2007 Elsevier Ltd. All rights reserved.

In vitro caecal fermentation of carbohydrate-rich feedstuffs in rabbits as affected by substrate pre-digestion and donors' diet

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C. Ocasio-Vega

2018-03-01

Full Text Available The influence of substrate pre-digestion and donors’ diet on in vitro caecal fermentation of different substrates in rabbits was investigated. Eight crossbreed rabbits were fed 2 experimental diets containing either low (LSF; 84.0 g/kg dry matter [DM] or high soluble fibre (HSF; 130 g/kg DM levels. In vitro incubations were conducted using batch cultures with soft faeces as inoculum and four fibrous or fibre-derived, low-starch and low-protein substrates: D-cellobiose (CEL, sugar beet pectin (PEC, sugar beet pulp (SBP and wheat straw (WS. Substrates in half of the cultures were subjected to a 2-step pepsin/pancreatin in vitro digestion without filtration, and the whole residue (soluble, insoluble and added enzymes was incubated at 39°C. Gas production was measured until 144 h, and volatile fatty acid (VFA production at 24 h incubation was determined. Cultures without substrate (blanks were included to correct gas production values for gas released from endogenous substrates and added enzymes. Pre-digestion had no influence on in vitro gas production kinetic of WS, and only reduced the time before gas production begins (lag time; by 31%; P=0.042 for SBP, but for both substrates the pre-digestion decreased the molar proportion of acetate (by 9%; P≤0.003 and increased those of propionate and butyrate (P≤0.014. For CEL, the pre-digestion increased the gas and total VFA production (by 30 and 114%, shortened the lag time (by 32%, and only when it was combined with LSF inoculum 38 percentage units of acetate were replaced by butyrate (P≤0.039. Treatments had a minor influence on in vitro fermentation traits of SBP pectin. The results showed that the pre-digestion process influenced the in vitro caecal fermentation in rabbits, but the effects were influenced by donors’ diet and the incubated substrate. Pre-digestion of substrate is recommended before conducting in vitro caecal fermentations. The level of soluble fibre in the donors’ diet

Microbial behavior and changes in food constituents during fermentation of Japanese sourdoughs with different rye and wheat starting materials.

Science.gov (United States)

Fujimoto, Akihito; Ito, Keisuke; Itou, Madoka; Narushima, Noriko; Ito, Takayuki; Yamamoto, Akihisa; Hirayama, Satoru; Furukawa, Soichi; Morinaga, Yasushi; Miyamoto, Takahisa

2018-01-01

Sourdough is a food item made by kneading grain flour and water together and allowing fermentation through the action of lactic acid bacteria (Lactobacillales) and yeast. Typically, Japanese bakeries make sourdough with rye flour, wheat flour, malt extract, and water and allow spontaneous fermentation for 6 days. We compared the microbial behavior and food components, such as organic acids, sugars, and free amino acids, of sourdoughs made using two different rye and wheat flours during the 6-day fermentation period. Comparisons were made for two types of rye and wheat flours, using different production sites and different milling, distribution, and storage conditions. The microbial count was evaluated using different culture media. All sourdough types showed a significant increase in lactic acid levels on fermentation day 2 and a decrease in free amino acid levels on day 4. Low overall lactic acid production and little fluctuation in sugar levels occurred in sourdough made from French ingredients. For sourdough made from Japanese ingredients, sugar levels (chiefly glucose, sucrose, and maltose) declined on fermentation day 1, increased on day 2, and declined by day 5. With the French ingredients, no yeast cells were detected until day 3, and many acid precursors of sourdough flavor components were detected. Yet with the Japanese ingredients, 10 6 /g yeast cells were detected on days 3-5, as well as sourdough-flavor esters and alcohols. Differences in raw material quality affected the microbial behavior and changes in food constituents during the fermentation process and, consequently, the sourdough flavor. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Sugar and pH dual-responsive mesoporous silica nanocontainers based on competitive binding mechanisms

Science.gov (United States)

Yilmaz, M. Deniz; Xue, Min; Ambrogio, Michael W.; Buyukcakir, Onur; Wu, Yilei; Frasconi, Marco; Chen, Xinqi; Nassar, Majed S.; Stoddart, J. Fraser; Zink, Jeffrey I.

2014-12-01

A sugar and pH dual-responsive controlled release system, which is highly specific towards molecular stimuli, has been developed based on the binding between catechol and boronic acid on a platform of mesoporous silica nanoparticles (MSNs). By grafting phenylboronic acid stalks onto the silica surface, catechol-containing β-cyclodextrins can be attached to the orifices of the MSNs' nanopores through formation of boronate esters which block access to the nanopores. These esters are stable enough to prevent cargo molecules from escaping. The boronate esters disassociate in the presence of sugars, enabling the molecule-specific controlled-release feature of this hybrid system. The rate of release has been found to be tunable by varying both the structures and the concentrations of sugars, as a result of the competitive binding nature associated with the mechanism of its operation. Acidification also induces the release of cargo molecules. Further investigations show that the presence of both a low pH and sugar molecules provides cooperative effects which together control the rate of release.A sugar and pH dual-responsive controlled release system, which is highly specific towards molecular stimuli, has been developed based on the binding between catechol and boronic acid on a platform of mesoporous silica nanoparticles (MSNs). By grafting phenylboronic acid stalks onto the silica surface, catechol-containing β-cyclodextrins can be attached to the orifices of the MSNs' nanopores through formation of boronate esters which block access to the nanopores. These esters are stable enough to prevent cargo molecules from escaping. The boronate esters disassociate in the presence of sugars, enabling the molecule-specific controlled-release feature of this hybrid system. The rate of release has been found to be tunable by varying both the structures and the concentrations of sugars, as a result of the competitive binding nature associated with the mechanism of its operation

A site-specific and multi-element isotopic approach to origin inference of sugars in foods and beverages

International Nuclear Information System (INIS)

Martin, M.L.; Martin, G.J.; Guillou, C.

1991-01-01

A strategy is presented for the characterization of sugars according to their botanical origin. The samples fermented in standardized conditions can be described in the multi-dimensional space of the overall carbon isotope ratio of ethanol measured by isotope ratio mass spectrometry (IRMS) and of the specific hydrogen isotope parameters of the methyl and methylene sites derived from nuclear magnetic resonance investigation of site-specific natural isotope fractionation (SNIF-NMR method). In the comparison of natural juices, the deuterium and oxygen-18 parameters of water extracted from the juice and from the end fermentation medium also contain information on the origin of the product. The isotopic effects of the concentration processes leading to concentrated juices, musts and syrups can be estimated and taken into account in interpreting the data. The classification power of this multi-element and multi-site approach is illustrated by discriminant analyses involving selected isotopic variables associated with pineapple, apple and barley sugars, compared to beet and cane sugars which are common sources of enrichment. The ability of the method to detect adulteration by exogenous sugars is improved when environmental conditions can be taken into account. (authors)

Bioethanol production from date palm fruit waste fermentation using ...

African Journals Online (AJOL)

CDPW is a renewable and sustainable resource of energy that is not greatly used in industries. The date is rich in biodegradable sugars, providing bioethanol after fermentation during 72 h at 30°C in the presence of Saccharomyces cerevisiae yeast and the distillation of date's juice obtained. In the first experience, a solar ...

The optimization of l-lactic acid production from sweet sorghum juice by mixed fermentation of Bacillus coagulans and Lactobacillus rhamnosus under unsterile conditions.

Science.gov (United States)

Wang, Yong; Chen, Changjing; Cai, Di; Wang, Zheng; Qin, Peiyong; Tan, Tianwei

2016-10-01

The cost reduction of raw material and sterilization could increase the economic feasibility of l-lactic acid fermentation, and the development of an cost-effective and efficient process is highly desired. To improve the efficiency of open fermentation by Lactobacillus rhamnosus based on sweet sorghum juice (SSJ) and to overcome sucrose utilization deficiency of Bacillus coagulans, a mixed fermentation was developed. Besides, the optimization of pH, sugar concentration and fermentation medium were also studied. Under the condition of mixed fermentation and controlled pH, a higher yield of 96.3% was achieved, compared to that (68.8%) in sole Lactobacillus rhamnosus fermentation. With an optimized sugar concentration and a stepwise-controlled pH, the l-lactic acid titer, yield and productivity reached 121gL(-1), 94.6% and 2.18gL(-1)h(-1), respectively. Furthermore, corn steep powder (CSP) as a cheap source of nitrogen and salts was proved to be an efficient supplement to SSJ in this process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acid hydrolysis of Curcuma longa residue for ethanol and lactic acid fermentation.

Science.gov (United States)

Nguyen, Cuong Mai; Nguyen, Thanh Ngoc; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Park, Youn-Je; Kim, Jin-Cheol

2014-01-01

This research examines the acid hydrolysis of Curcuma longa waste, to obtain the hydrolysate containing lactic acid and ethanol fermentative sugars. A central composite design for describing regression equations of variables was used. The selected optimum condition was 4.91% sulphuric acid, 122.68°C and 50 min using the desirability function under the following conditions: the maximum reducing sugar (RS) yield is within the limited range of the 5-hydroxymethylfurfural (HMF) and furfural concentrations. Under the condition, the obtained solution contained 144 g RS/L, 0.79 g furfural/L and 2.59 g HMF/L and was directly fermented without a detoxification step. The maximum product concentration, average productivity, RS conversion and product yield were 115.36 g/L, 2.88 g/L/h, 89.43% and 64% for L-lactic acid; 113.92 g/L, 2.59 g/L/h, 88.31% and 63.29% for D-lactic acid; and 55.03 g/L, 1.38 g/L/h, 42.66 and 30.57%, respectively, for ethanol using a 7-L jar fermenter. Copyright © 2013. Published by Elsevier Ltd.

Assessment of chemical and sensory quality of sugarcane alcoholic fermented beverage.

Science.gov (United States)

Resende Oliveira, Érica; Caliari, Márcio; Soares Soares Júnior, Manoel; Ribeiro Oliveira, Aryane; Cristina Marques Duarte, Renata; Valério de Barros Vilas Boas, Eduardo

2018-01-01

This study aimed to verify the technological feasibility, chemical quality and sensory acceptance of alcoholic fermented beverage obtained from sugarcane juice. A completely randomized design was applied. Sugar and alcohol content, phenolic (HPLC-MS) and volatile (GS-MS) compounds, pH, density, dry matter and acidity of the fermented beverage of sugarcane were quantified, as well as the acceptance of the product was carried out. The complete fermentation of sugarcane lasted 7 days, and it was obtained an alcohol content of 8.0% v/v. Titrable acidity of the beverage was of 67.31 meq L -1 , pH 4.03, soluble solids of 5 °Brix, reducing sugar of 0.07 g glucose 100 g -1 , density of 0.991 g cm -3 , reduced dry matter of 14.15 g L -1 , sulfates lower than 0.7 g K 2 SO 4  L -1 . Various phenolic compounds, among which, gallic acid (10.97%), catechin (1.73%), chlorogenic acid (3.52%), caffeic acid (1.49%), vanillic acid (0.28%), p -coumaric acid (0.24%), ferulic acid (6.63%), m -coumaric acid (0.36%), and o -coumaric acid (0.04%). Amongst aromatic compounds, were found mainly esters with fruity aromas (ethyl ester hexanoic acid and ethyl ester octanoic acid). The sugarcane juice can be commercialized as an alternative wine, as it presented adequate features to an alcoholic fermented beverage and was sensory accepted by consumers.

Pretreatment and fermentation strategies to overcome the toxicity of acetic acid in hemicellulosic hydrolysates

DEFF Research Database (Denmark)

Mussatto, Solange I.

Acetic acid is one of the most important toxic compounds present in hemicellulosic hydrolysates. In order to overcome this problem, several strategies were studied for both biomass pretreatment and fermentation steps. Biomass deacetylation by mild alkaline pretreatment or using high pressure CO2...... where acetic acid can also be integrated as a valuable final product. For the fermentation step, it is well known that hemicellulosic hydrolysates usually need to be detoxified prior use as fermentation medium in order to improve the performance of the microorganism to convert sugars in the product...... of interest. Although detoxification improves the fermentability of hydrolysates, this additional step adds cost and complexity to the process and generates extra waste products. In this sense, the adaptation of the fermenting microorganism to increased concentrations of acetic acid can be considered...

Bioethanol Production from Sugarcane Bagasse by a Novel Brazilian Pentose Fermenting Yeast Scheffersomyces shehatae UFMG-HM 52.2: Evaluation of Fermentation Medium

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F. A. F. Antunes

2014-01-01

Full Text Available Bioconversion of hemicellulosic sugars into second generation (2G ethanol plays a pivotal role in the overall success of biorefineries. In this study, ethanol production performance of a novel xylose-fermenting yeast, Scheffersomyces shehatae UFMG-HM 52.2, was evaluated under batch fermentation conditions using sugarcane bagasse (SB hemicellulosic hydrolysate as carbon source. Dilute acid hydrolysis of SB was performed to obtain sugarcane bagasse hemicellulosic hydrolysate (SBHH. It was concentrated, detoxified, and supplemented with nutrients in different formulations to prepare the fermentation medium to the yeast evaluation performance. S. shehatae UFMG-HM 52.2 (isolated from Brazilian Atlantic rain forest ecosystem was used in fermentations carried out in Erlenmeyer flasks maintained in a rotator shaker at 30°C and 200 rpm for 72 h. The use of a fermentation medium composed of SBHH supplemented with 5 g/L ammonium sulfate, 3 g/L yeast extract, and 3 g/L malt extract resulted in 0.38 g/g of ethanol yield and 0.19 g L.h of volumetric productivity after 48 h of incubation time.

Ethanol Production from Brewers’ Spent Grain Pretreated by Dilute Phosphoric Acid

DEFF Research Database (Denmark)

Rojas-Chamorro, José A.; Cara, Cristóbal; Romero, Inmaculada

2018-01-01

of both pretreatment and enzymatic hydrolysis together recovered 92% of total sugars in BSG, mainly solubilized in the prehydrolysate (63%). Escherichia coli SL100 fermented this mixed sugar solution containing hemicellulosic sugars and starchy glucose without previous detoxification with an ethanol yield...... in this work allowed 69% of the total sugars in the BSG to be converted to ethanol....... of 0.40 g/g. Considering also the glucose released from the cellulosic structure and converted to ethanol by a simultaneous saccharification and fermentation process, an overall ethanol yield of 17.9 g of ethanol per 100 g of raw BSG was achieved. Thereby, the process configuration proposed...

Are sugar-free confections really beneficial for dental health?

Science.gov (United States)

Nadimi, H; Wesamaa, H; Janket, S-J; Bollu, P; Meurman, J H

2011-10-07

Various sugar substitutes have been introduced and are widely used in confections and beverages to avoid tooth decay from sugar and other fermentable carbohydrates. One group of sugar substitutes are sugar alcohols or polyols. They have been specifically used in foods for diabetic patients because polyols are not readily absorbed in the intestine and blood stream, preventing post-prandial elevation of glucose level. Additionally they may lower caloric intake. We searched PubMed, Cochrane Controlled Trials Registry, Cochrane Oral Health Review, Centre for Reviews and Dissemination in the UK, National Library for Public Health and a Centre for Evidence Based Dentistry website up to the end of October 2010, using the search terms 'sugar alcohol' or 'sugar-free' or 'polyols' and combined with a search with terms 'dental caries' or 'dental erosion'. Xylitol, a polyol, has been approved by the US Food and Drug Administration for its non-cariogenic properties that actually reduce the risk of dental decay and recently, the European Union also officially approved a health claim about xylitol as a 'tooth friendly' component in chewing gums. Although the presence of acidic flavourings and preservatives in sugar-free products has received less attention, these additives may have adverse dental health effects, such as dental erosion. Furthermore, the term sugar-free may generate false security because people may automatically believe that sugar-free products are safe on teeth. We concluded that polyol-based sugar-free products may decrease dental caries incidence but they may bring another dental health risk, dental erosion, if they contain acidic flavouring. There is a need for properly conducted clinical studies in this area.

Engineering Saccharomyces cerevisiae To Release 3-Mercaptohexan-1-ol during Fermentation through Overexpression of an S. cerevisiae Gene, STR3, for Improvement of Wine Aroma▿

Science.gov (United States)

Holt, Sylvester; Cordente, Antonio G.; Williams, Simon J.; Capone, Dimitra L.; Jitjaroen, Wanphen; Menz, Ian R.; Curtin, Chris; Anderson, Peter A.

2011-01-01

Sulfur-containing aroma compounds are key contributors to the flavor of a diverse range of foods and beverages. The tropical fruit characters of Vitis vinifera L. cv. Sauvignon blanc wines are attributed to the presence of the aromatic thiols 3-mercaptohexan-1-ol (3MH), 3-mercaptohexan-1-ol-acetate, and 4-mercapto-4-methylpentan-2-one (4MMP). These volatile thiols are found in small amounts in grape juice and are formed from nonvolatile cysteinylated precursors during fermentation. In this study, we overexpressed a Saccharomyces cerevisiae gene, STR3, which led to an increase in 3MH release during fermentation of a V. vinifera L. cv. Sauvignon blanc juice. Characterization of the enzymatic properties of Str3p confirmed it to be a pyridoxal-5′-phosphate-dependent cystathionine β-lyase, and we demonstrated that this enzyme was able to cleave the cysteinylated precursors of 3MH and 4MMP to release the free thiols. These data provide direct evidence for a yeast enzyme able to release aromatic thiols in vitro that can be applied in the development of self-cloned yeast to enhance wine flavor. PMID:21478306

UTILIZATION OF OIL PALM EMPTY FRUIT BUNCH (OPEFB FOR BIOETHANOL PRODUCTION THROUGH ALKALI AND DILUTE ACID PRETREATMENT AND SIMULTANEOUS SACCHARIFICATION AND FERMENTATION

Directory of Open Access Journals (Sweden)

Yanni Sudiyani

2010-07-01

Full Text Available Lignocellulosic biomass is a potential alternative source of bioethanol for energy. The lignocellulosics are abundantly available in Indonesia. Most of them are wastes of agriculture, plantation and forestry. Among those wastes, oil palm empty fruit bunch (OP EFB is one of a potential lignocellulosics to be converted to bioethanol. This EFB, which is wastes in oil palm factories, is quite abundant (around 25 million tons/year and also has high content of cellulose (41-47%. The conversion of OPEFB to ethanol basically consists of three steps which are pretreatment, hydrolysis of cellulose and hemicellulose to simple sugars (hexoses and pentoses, and fermentation of simple sugars to ethanol. Acid and alkali pretreatments are considered the simplest methods and are potentially could be applied in the next couple of years. However, there are still some problems that have to be overcome to make the methods economically feasible. The high price of cellulose enzyme that is needed in the hydrolysis step is one of factors that cause the cost of EFB conversion is still high. Thus, the search of potential local microbes that could produce cellulase is crucial. Besides that, it is also important to explore fermenting microbes that could ferment six carbon sugars from cellulose as well as five carbon sugars from hemicellulose, so that the conversion of lignocellulosics, particularly EFB, would be more efficient. Keywords: OPEFB, lignocellulosics, pretreatment, fermentation, ethanol

Effect of initial ph on growth characteristics and fermentation properties of Saccharomyces cerevisiae.

Science.gov (United States)

Liu, Xingyan; Jia, Bo; Sun, Xiangyu; Ai, Jingya; Wang, Lihua; Wang, Cheng; Zhao, Fang; Zhan, Jicheng; Huang, Weidong

2015-04-01

As the core microorganism of wine making, Saccharomyces cerevisiae encounter low pH stress at the beginning of fermentation. Effect of initial pH (4.50, 3.00, 2.75, 2.50) on growth and fermentation performance of 3 S. cerevisiae strains Freddo, BH8, Nº.7303, different tolerance at low pH, chosen from 12 strains, was studied. The values of yeast growth (OD600 , colony forming units, cell dry weight), fermentation efficiency (accumulated mass loss, change of total sugar concentration), and fermentation products (ethanol, glycerol, acetic acid, and l-succinic acid) at different pH stress were measured. The results showed that the initial pH of must was a vital factor influencing yeast growth and alcoholic fermentation. Among the 3 strains, strain Freddo and BH8 were more tolerant than Nº.7303, so they were affected slighter than the latter. Among the 4 pH values, all the 3 strains showed adaptation even at pH 2.50; pH 2.75 and 2.50 had more vital effect on yeast growth and fermentation products in contrast with pH 4.50 and 3.00. In general, low initial pH showed the properties of prolonging yeast lag phase, affecting accumulated mass loss, changing the consumption rate of total sugar, increasing final content of acetic acid and glycerol, and decreasing final content of ethanol and l- succinic acid, except some special cases. Based on this study, the effect of low pH on wine products would be better understood and the tolerance mechanism of low pH of S. cerevisiae could be better explored in future. © 2015 Institute of Food Technologists®

An evolved xylose transporter from Zymomonas mobilis enhances sugar transport in Escherichia coli

Directory of Open Access Journals (Sweden)

Zhang Jingqing

2009-12-01

Full Text Available Abstract Background Xylose is a second most abundant sugar component of lignocellulose besides glucose. Efficient fermentation of xylose is important for the economics of biomass-based biorefineries. However, sugar mixtures are sequentially consumed in xylose co-fermentation with glucose due to carbon catabolite repression (CCR in microorganisms. As xylose transmembrance transport is one of the steps repressed by CCR, it is therefore of interest to develop a transporter that is less sensitive to the glucose inhibition or CCR. Results The glucose facilitator protein Glf transporter from Zymomonas mobilis, also an efficient transporter for xylose, was chosen as the target transporter for engineering to eliminate glucose inhibition on xylose uptake. The evolution of Glf transporter was carried out with a mixture of glucose and xylose in E. coli. Error-prone PCR and random deletion were employed respectively in two rounds of evolution. Aided by a high-throughput screening assay using xylose analog p-nitrophenyl-β-D-xylopyranoside (pNPX in 96-well plates, a best mutant 2-RD5 was obtained that contains several mutations, and a deletion of 134 residues (about 28% of total residues, or three fewer transmembrane sections (TMSs. It showed a 10.8-fold improvement in terms of pNPX transport activity in the presence of glucose. The fermentation performance results showed that this mutant improved xylose consumption by 42% with M9 minimal medium containing 20 g L-1 xylose only, while with the mixture sugar of xylose and glucose, 28% more glucose was consumed, but no obvious co-utilization of xylose was observed. Further glucose fed-batch experiments suggested that the intracellular metabolism of xylose was repressed by glucose. Conclusions Through random mutagenesis and partial deletion coupled with high-throughput screening, a mutant of the Glf transporter (2-RD5 was obtained that relieved the inhibition of xylose transport by glucose. The fermentation

Production of bacterial protein from sugar cane bagasse pith

Energy Technology Data Exchange (ETDEWEB)

Molina, O E; Callieri, D A.S.; Perotti de Galvez, N

1980-01-01

Bacterial protein was produced during the fermentation of sugar cane bagasse pith (BP) by a mixture of cellulolytic bacteria, one of them being a species of Cellulomonas. If the BP were treated with 1% NaOH prior to fermentation, the liquor could be used twice more without affecting the yield of bacterial protein. After that, the liquor became too dark and impaired the subsequent washing of BP. If the concentration of N (as NaN0/sub 3/) in the fermentation medium were raised, the conversion factor to protein was lowered, but the amount of protein formed per L per h and the ratio of protein to BP became higher. The evolution of pH, the dry matter content, cellulolytic activity, and protein yield were all affected by the type of N source used. The yield of bacterial protein can probably be increased by automatically controlling the pH and dissolved O levels of the culture.

The influence of brewers' yeast addition on lactic acid fermentation of brewers' spent grain hydrolysate by Lactobacillus rhamnosus

OpenAIRE

Pejin, Jelena; Radosavljević, Miloš; Kocić-Tanackov, Sunčica; Đukić-Vuković, Aleksandra; Mladenović, Dragana; Mojović, Ljiljana

2015-01-01

In this study brewers' spent grain (BSG) hydrolysate was produced using optimal conditions. Hydrolysates were used for lactic acid fermentation by Lactobacillus rhamnosus ATCC 7469. The aim of this study was to evaluate possibilities of the BSG hydrolysate utilization as a substrate for lactic acid fermentation as well as the effect of dry brewers' yeast (1.0, 3.0, and 5.0 %) addition in hydrolysate on lactic acid fermentation parameters (L-(+)-lactic acid and reducing sugars concentration an...

Conversion of lignocellulosic waste by gamma irradiation and fungal fermentation

International Nuclear Information System (INIS)

Le Xuan Tham; Nguyen Duy Hang; Tran Huu Do; Hoang Thi My Linh; Nguyen Duy Lam

2000-01-01

Effects of microbial elimination (initially contaminated bacteria and fungi) were confirmed at wide range of irradiation doses (15-30 kGy) with gamma rays of Co-60 for substrates with sawdusts, sugar cane baggasse, rice straw, oil palm fibre and others. Some changes of main components of basic polysaccharides and nitrogen sources in substrates under irradiation and fermentations have been examined to confirm effective conversions and assimilations of inorganic nitrogen into protein, particularly using N-15 tracer techniques. Biomass obtained by fungal fermentations would be used for animal feed and spent compots were useful for biofertilizer production. (author)

A comparison of ethanol and methane fermentation of currant-and sultana-washing wastewater

Energy Technology Data Exchange (ETDEWEB)

Athanasopoulos, Nikolaos (Patras Univ. (Greece). Dept. of Chemistry)

1994-01-01

Wastewater from currant- and sultana-washing processes was successfully treated in an ethanol fermenter at 33[sup o]C; the pH of the wash water was controlled at 2.8; the reducing sugar content was 38.8 g/litre; commercial baker's yeast was used as inoculum at a concentration of 2.5 g/litre; formaldehyde at a concentration of 150 mg/litre was used as antiseptic; the ethanol yield was 70.6% of the theoretical value in 24 h; the COD removal after a single distillation was 84%. The overall economics of ethanol fermentation are very promising compared to methane fermentation. (author)

Relationship to reducing sugar production and scanning electron microscope structure to pretreated hemp hurd biomass (Cannabis sativa)

International Nuclear Information System (INIS)

Abraham, Reinu E.; Barrow, Colin J.; Puri, Munish

2013-01-01

Lignocellulosic biomass is a highly rigid and recalcitrant structure which requires pretreatment to loosen chemical bonds to make accessible monomeric sugars for biofuel production. In this study, locally available biomass, that is hemp (Cannabis sativa), a low cost feedstock for ethanol production, has been used for the production of fermentable sugars. Hemp hurd biomass (HHB) was exposed to five different pretreatments which included dilute acid (H 2 SO 4 ), alkaline (NaOH), alkaline peroxide, hot water and one stage dilute acid (H 2 SO 4 ). Different pretreatments resulted in loosening and degradation of HHB structure thus facilitating enzymatic saccharification at optimized parameters (pH–4.8 and 50 °C). The changes in the reactive groups (hydroxyl or acetyl) of the HHB were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Scanning electron microscopy (SEM) was employed to characterize the surface morphology of untreated and treated HHB. Finally, enzymatic saccharification demonstrated maximum yield of total sugars (743 mg g −1 ) that are suitable for biofuel production. -- Highlights: • Hemp hurd biomass (HHB) was used for producing fermentable sugars. • Alkaline pretreatment resulted in loosening and degradation of hemp structure. • Pretreated HHB was characterized using FTIR studies. • SEM studies evaluated the opening of fiber bundles in pretreatment, thereby increasing cellulose access to enzymes. • Enzymatic saccharification of pretreated HHB demonstrated maximum yield of reducing sugars

Effects of Temperature,Mother of Vinegar, and Amount of Sugar on AroniamelanocarpaChokeberry Fermentation

OpenAIRE

Won Sik Choi; Soon Hong Kwon; Sung Won Chung; Soon Goo Kwon; Jong Min Park; Jong Soon Kim; Destiani Supeno

2016-01-01

This study evaluatesthe effects of temperature, mother of vinegar, and amount of sugaron the fermentation of black chokeberry (Aroniamelanocarpa). To investigate temperature, samples of black chokeberrieswere compared after fermentation in a thermostat incubator (T 40ᵒC) and at room temperature (T 25ᵒC). Six mothers of vinegar were also used: white grape vinegar, brown rice black vinegar (pomegranate), brown rice black vinegar (blackberry and blueberry), pomegranate vinegar, brown rice vinega...

Fermented inulin hydrolysate by Bifidobacterium breve as cholesterol binder in functional food application

Science.gov (United States)

Melanie, Hakiki; Susilowati, Agustine; Maryati, Yati

2017-01-01

Inulin hydrolysate is a result of inulin hydrolysis by inulinase enzyme of Scopulariopsis sp.-CBS1 fungi isolated from dahlia tuber skin in the formation of fructooligosaccharides (FOS) as dietary fiber. Inulin hydrolysate fermented by Bifidobacterium breve has a potential as cholesterol binder in digestive system due to dietary fiber content in inulin. This study was conducted to evaluate the best cholesterol binding capacity by the variation of lactic acid bacteria (LAB) culture concentration of 10%, 20% and 30% (v/v), respectively. Fermentation process were conducted with inulin hydrolysate concentration of 25% (w/v), skim milk 7,5% (w/v) and various LAB culture concentration at 40 °C for 0, 12, 24, 36 and 48 hours. The results showed that the variation of LAB culture concentrations affect the cholesterol binding ability in fermented inulin hydrolysate. The fermentation process with 10% LAB culture concentration at 40°C for 48 hours resulted in the highest cholesterol binding capacity (CBC) of 13,69 mg/g at pH 7and 14,44 mg/g at pH 2 with composition of total acids of 0,787%, soluble dietary fiber of 0,396%, insoluble dietary fiber of 5,47%, total solids of 14,476%, total sugars of 472,484 mg/mL, reducing sugar of 92 mg/mL and total plate count (TPC) of 7,278 log CFU/mL, respectively.

Yeast hybrids which ferment raffinose, and their application in the alcohol industry

Energy Technology Data Exchange (ETDEWEB)

Konovalov, S A; Raevskaya, O G; Kosikov, K V

1964-01-01

Saccharomyces carlsbergensis and some hybrids obtained earlier were crossed. Among the newly created hybrids one called hybrid No. 67 is very efficient with respect to the fermentation of raffinose (1). This is of interest in the fermentation of molasses high in I. On an industrial scale this hybrid could be employed to ferment molasses which had been diluted to about 5/sup 0/ Balling so as to produce a solution containing 7.5% ethanol and about 0.4% unfermented sugars, with a cell yield of 148 x 10/sup 6//ml. For molasses containing less than or equal to 4% I, these values can still be increased to 9% and 186 x 10/sup 6//ml, respectively.

Influence of Temperature and Carbon Dioxide on Fermentation of Cabernet Sauvignon Must

Directory of Open Access Journals (Sweden)

Jan Mavri

2003-01-01

Full Text Available In the process of wine fermentation temperature and the amount of carbon dioxide present represent parameters that can be easily monitored and controlled. The influence of variation of the process temperature and the fluxes of additional inlet gaseous carbon dioxide in Saccharomyces bayanus fermentation of Cabernet Sauvignon grape must on the accumulation of biomass and production of metabolites was studied. All experiments with temperature and redox potential control on-line were performed in a 10-litre laboratory stirred tank reactor. Metabolites of Saccharomyces bayanus fermentation comprising higher alcohols (1-propanol, 2-butanol, isoamyl alcohol, as well as reducing sugars, were measured off-line by gas and high pressure liquid chromatography.

FERMENTABLE SUGARS FROM Lupinus rotundiflorus BIOMASS BY HYDROCHLORIC ACID HYDROLYSIS

Directory of Open Access Journals (Sweden)

Mario A. Ruiz-López

2011-02-01

Full Text Available It is of general interest to produce fermentable carbohydrates from plant biomass. However, obtaining monosaccharides requires some effort, due to the intricate structure of the cell wall lignocellulosic complex. The aim of this study was to apply a simple two-stage hydrolysis process, using only concentrated hydrochloric acid, to generate fermentable carbohydrates from L. rotundiflorus biomass. First and second stage acid concentrations were 32% and 42.6%. Total monosaccharide yields with respect to dry matter after the first stage, second stage, and the overall process, were 27.5%, 21.0% and 48.4%, respectively. Xylose was the main first stage carbohydrate in the hydrolysate, followed by glucose, arabinose, and galactose. After the second stage only glucose and a small amount of xylose were detected. The polysaccharide hydrolysis was eased by overall low lignin content. Some advantages of this method were the use of a single hydrolyzing agent and that most of the polysaccharides were hydrolyzed in reasonably high yields. The acceptable yield, relative simplicity, the use of most of the biomass along with the wide availability, low cost of the chemicals, and the ample supply of lupines, would facilitate the scaling of these laboratory studies to pilot and industrial levels.

Fermentative utilization of coffee mucilage using Bacillus coagulans and investigation of down-stream processing of fermentation broth for optically pure l(+)-lactic acid production.

Science.gov (United States)

Neu, Anna-Katrin; Pleissner, Daniel; Mehlmann, Kerstin; Schneider, Roland; Puerta-Quintero, Gloria Inés; Venus, Joachim

2016-07-01

In this study, mucilage, a residue from coffee production, was investigated as substrate in fermentative l(+)-lactic acid production. Mucilage was provided as liquid suspension consisting glucose, galactose, fructose, xylose and sucrose as free sugars (up to 60gL(-1)), and used directly as medium in Bacillus coagulans batch fermentations carried out at 2 and 50L scales. Using mucilage and 5gL(-1) yeast extract as additional nitrogen source, more than 40gL(-1) lactic acid was obtained. Productivity and yield were 4-5gL(-1)h(-1) and 0.70-0.77g lactic acid per g of free sugars, respectively, irrespective the scale. Similar yield was found when no yeast extract was supplied, the productivity, however, was 1.5gL(-1)h(-1). Down-stream processing of culture broth, including filtration, electrodialysis, ion exchange chromatography and distillation, resulted in a pure lactic acid formulation containing 930gL(-1)l(+)-lactic acid. Optical purity was 99.8%. Copyright © 2016 Elsevier Ltd. All rights reserved.