Adaptive evolution of the lager brewing yeast Saccharomyces pastorianus for improved growth under hyperosmotic conditions and its influence on fermentation performance.

Science.gov (United States)

Ekberg, Jukka; Rautio, Jari; Mattinen, Laura; Vidgren, Virve; Londesborough, John; Gibson, Brian R

2013-05-01

An adaptive evolution method to obtain stable Saccharomyces pastorianus brewing yeast variants with improved fermentation capacity is described. The procedure involved selection for rapid growth resumption at high osmotic strength. It was applied to a lager strain and to a previously isolated ethanol-tolerant strain. Fermentation performance of strains was compared at 15 °P wort strength. A selected osmotolerant variant of the ethanol-tolerant strain showed significantly shorter fermentation time than the parent strain, producing 6.45% alcohol by volume beer in 4-5 days with mostly similar organoleptic properties to the original strain. Diacetyl and pentanedione contents were 50-75% and 3-methylbutyl acetate and 2-phenylethyl acetate 50% higher than with the original strain, leading to a small flavour change. The variant contained significantly less intracellular trehalose and glycogen than the parent. Transcriptional analysis of selected genes at 24 h revealed reduced transcription of hexose transport genes and increased transcription of the MALx1 and MALx2 genes, responsible for α-glucoside uptake and metabolism. It is suggested that an attenuated stress response contributes to the improved fermentation performance. Results show that sequential selection for both ethanol tolerance and rapid growth at high osmotic strength can provide strains with enhanced fermentation speed with acceptable product quality. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

An Inductive Logic Programming Approach to Validate Hexose Binding Biochemical Knowledge.

Science.gov (United States)

Nassif, Houssam; Al-Ali, Hassan; Khuri, Sawsan; Keirouz, Walid; Page, David

2010-01-01

Hexoses are simple sugars that play a key role in many cellular pathways, and in the regulation of development and disease mechanisms. Current protein-sugar computational models are based, at least partially, on prior biochemical findings and knowledge. They incorporate different parts of these findings in predictive black-box models. We investigate the empirical support for biochemical findings by comparing Inductive Logic Programming (ILP) induced rules to actual biochemical results. We mine the Protein Data Bank for a representative data set of hexose binding sites, non-hexose binding sites and surface grooves. We build an ILP model of hexose-binding sites and evaluate our results against several baseline machine learning classifiers. Our method achieves an accuracy similar to that of other black-box classifiers while providing insight into the discriminating process. In addition, it confirms wet-lab findings and reveals a previously unreported Trp-Glu amino acids dependency.

Enzyme study of the separate stages in alcohol fermentation

Energy Technology Data Exchange (ETDEWEB)

Mar Monux, D

1968-01-01

The precise roles of ATP, DNA, and NADP in interaction with enzymes in certain of the 11 phases of fermentation are outlined. Individual enzymes which take part in the 11 phases are: (1) hexose transferase; (2) phosphohexoseisomerase; (3) fructosinase; (4) aldolase; (5) an SH-enzyme; (6) 3-phosphoglycero-1-phosphotransferase; (7) ghosphoglyceromutosase; (8) 2-phosphoglycerohydrolase; (9) pyruvic transferase; (10) pyruvic decarboxylase; (11) alcohol dehydrogenase.

Complete Hexose Isomer Identification with Mass Spectrometry

Science.gov (United States)

Nagy, Gabe; Pohl, Nicola L. B.

2015-04-01

The first analytical method is presented for the identification and absolute configuration determination of all 24 aldohexose and 2-ketohexose isomers, including the D and L enantiomers for allose, altrose, galactose, glucose, gulose, idose, mannose, talose, fructose, psicose, sorbose, and tagatose. Two unique fixed ligand kinetic method combinations were discovered to create significant enough energetic differences to achieve chiral discrimination among all 24 hexoses. Each of these 24 hexoses yields unique ratios of a specific pair of fragment ions that allows for simultaneous determination of identification and absolute configuration. This mass spectrometric-based methodology can be readily employed for accurate identification of any isolated monosaccharide from an unknown biological source. This work provides a key step towards the goal of complete de novo carbohydrate analysis.

Tunable GLUT-Hexose Binding and Transport via Modulation of Hexose C-3 Hydrogen-Bonding Capabilities.

Science.gov (United States)

Kumar Kondapi, Venkata Pavan; Soueidan, Olivier-Mohamad; Cheeseman, Christopher I; West, Frederick G

2017-06-12

The importance of the hydrogen bonding interactions in the GLUT-hexose binding process (GLUT=hexose transporter) has been demonstrated by studying the binding of structurally modified d-fructose analogues to GLUTs, and in one case its transport into cells. The presence of a hydrogen bond donor at the C-3 position of 2,5-anhydro-d-mannitol derivatives is essential for effective binding to GLUT5 and transport into tumor cells. Surprisingly, installation of a group that can function only as a hydrogen bond acceptor at C-3 resulted in selective recognition by GLUT1 rather than GLUT5. A fluorescently labelled analogue clearly showed GLUT-mediated transport and low efflux properties of the probe. This study reveals that a single positional modification of a 2,5-anhydro-d-mannitol derivative is sufficient to switch its binding preference from GLUT5 to GLUT1, and uncovers general scaffolds that are suitable for the potential selective delivery of molecular payloads into tumor cells via GLUT transport machinery. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of hexose transporters in Yarrowia lipolytica reveals new groups of Sugar Porters involved in yeast growth.

Science.gov (United States)

Lazar, Zbigniew; Neuvéglise, Cécile; Rossignol, Tristan; Devillers, Hugo; Morin, Nicolas; Robak, Małgorzata; Nicaud, Jean-Marc; Crutz-Le Coq, Anne-Marie

2017-03-01

Sugar assimilation has been intensively studied in the model yeast S. cerevisiae, and for two decades, it has been clear that the homologous HXT genes, which encode a set of hexose transporters, play a central role in this process. However, in the yeast Yarrowia lipolytica, which is well-known for its biotechnological applications, sugar assimilation is only poorly understood, even though this yeast exhibits peculiar intra-strain differences in fructose uptake: some strains (e.g., W29) are known to be slow-growing in fructose while others (e.g., H222) grow rapidly under the same conditions. Here, we retrieved 24 proteins of the Sugar Porter family from these two strains, and determined that at least six of these proteins can function as hexose transporters in the heterologous host Saccharomyces cerevisiae EBY.VW4000. Transcriptional studies and deletion analysis in Y. lipolytica indicated that two genes, YHT1 and YHT4, are probably the main players in both strains, with a similar role in the uptake of glucose, fructose, and mannose at various concentrations. The other four genes appear to constitute a set of 'reservoir' hexose transporters with an as-yet unclear physiological role. Furthermore, through examining Sugar Porters of the entire Yarrowia clade, we show that they constitute a dynamic family, within which hexose transport genes have been duplicated and lost several times. Our phylogenetic analyses support the existence of at least three distinct evolutionary groups of transporters which allow yeasts to grow on hexoses. In addition to the well-known and widespread Hxt-type transporters (which are not essential in Y. lipolytica), we highlight a second group of transporters, represented by Yht1, which are phylogenetically related to sensors that play a regulatory role in S. cerevisiae, and a third group, represented by Yht4, previously thought to contain only high-affinity glucose transporters related to Hgt1of Kluyveromyces lactis. Copyright © 2017

Gastric emptying of hexose sugars: role of osmolality, molecular structure and the CCK₁ receptor.

Science.gov (United States)

Little, T J; Gopinath, A; Patel, E; McGlone, A; Lassman, D J; D'Amato, M; McLaughlin, J T; Thompson, D G

2010-11-01

It is widely reported that hexose sugars slow gastric emptying (GE) via osmoreceptor stimulation but this remains uncertain. We evaluated the effects of a panel of hexoses of differing molecular structure, assessing the effects of osmolality, intra-individual reproducibility and the role of the CCK(1) receptor, in the regulation of GE by hexoses. Thirty one healthy non-obese male and female subjects were studied in a series of protocols, using a (13) C-acetate breath test to evaluate GE of varying concentrations of glucose, galactose, fructose and tagatose, with water, NaCl and lactulose as controls. GE was further evaluated following the administration of a CCK(1) receptor antagonist. Three subjects underwent repeated studies to evaluate intra-individual reproducibility. At 250 mOsmol, a hexose-specific effect was apparent: tagatose slowed GE more potently than water, glucose and fructose (P effects of hexose sugars on GE appear related to their molecular structure rather than osmolality per se, and are, at least in part, CCK(1) receptor-dependent. © 2010 Blackwell Publishing Ltd.

Investigation of hydrolysis products in the acetone-butanol fermentation of vegetable agricultural waste materials

Energy Technology Data Exchange (ETDEWEB)

Nakhmanovich, B M

1960-01-01

Determinations of the fundamental chemical composition of corn stalk, sunflower husk, and hemp scutch by chromatography were reported, e.g. pentoses (1.98, 1.98, 2.01%), hexoses (1.59, 1.72, 2.01% respectively.) and various amino acids (arginine, asparagine, histidine, glutamine, glycine, lysine, proline, serine, tyrosine, threonine, cysteine, cystine, alanine, and aspartic and glutamic acids). The sterilized products from the hydrolysis (pentoses, hexoses) in a combined mixture with a meal mash were normally fermented at 37/sup 0/ in the presence of acetone-butanol bacteria for 40 to 48 hours, yielding 10.46 to 12.50% of acetone, 15.09 to 18.0% of butanol, 3.79 to 6.08% of ethanol (a total yielding being 30 to 42% of solvents).

Exploring the potential of lactic acid production from lignocellulosic hydrolysates with various ratios of hexose versus pentose by Bacillus coagulans IPE22.

Science.gov (United States)

Wang, Yujue; Cao, Weifeng; Luo, Jianquan; Wan, Yinhua

2018-08-01

The aim of this study was to investigate the feasibility of utilizing different lignocellulosic hydrolysates with various hexose versus pentose (H:P) ratios to produce lactic acid (LA) from Bacillus coagulans IPE22 by fermentations with single and mixed sugar. In single sugar utilization, glucose tended to promote LA production, and xylose preferred to enhance cell growth. In mixed sugar utilization, glucose and pentose were consumed simultaneously when glucose concentration was lower than 20 g/L, and almost the same concentration of LA (50 g/L) was obtained regardless of the differences of H:P values. Finally, LA production from corn cob hydrolysates (CCH) contained 60 g/L mixed sugar verified the mechanisms found in the fermentations with simulated sugar mixture. Comparing with single glucose utilization, CCH utilization was faster and the yield of LA was not significantly affected. Therefore, the great potential of producing LA with lignocellulosic materials by B. coagulans was proved. Copyright © 2018. Published by Elsevier Ltd.

Rapid analytical extraction of volatile fermentation products

Energy Technology Data Exchange (ETDEWEB)

Jansen, N B; Flickinger, M C; Tsao, G T

1979-10-01

With renewed interest in production of liquid fuels and chemical feedstocks from carbohydrates, numerous authors have utilized gas-liquid chromatography (GC) for quantification of volatile products. Poor separation and short column life will result if residual sugars present in the medium are not separated from the volatile compounds before injection. In our current investigation of 2,3-butanediol production from xylose, we have developed a rapid GC assay for 2,3-butanediol, acetyl methyl carbinol (acetoin), 2,3-butanedione (diacetyl), and ethanol. This method extracts the fermentation products at high pH from residual xylose before injection into the GC. This routine is a modification of the method of Kolfenbach et al. and is more rapid than the method of separation of diacetyl and acetoin from carbohydrates by distillation reported by Gupta et al. Their erroneous reports of yields of 640 mg diacetyl + acetoin/g sugar are 30% higher than the theoretical maximum for Enterobacter cloacae (ATCC 27613) and points out the need for a reliable, accurate assay for these products.

A procedure for batch separation of 14C-hexose from 14C-sucrose

International Nuclear Information System (INIS)

Tarpley, L.; Vietor, D.M.

1991-01-01

This presentation describes a method for separating 14 C-hexose from 14 C-sucrose in extracts of plant tissue. Portions of ethanol extracts are treated with activated charcoal in microcentrifuge tubes. Aliquots are removed, ethanol evaporated and replaced with reaction mixture that phosphorylates hexose (HEPPS, K 2 HPO 4 , Mg(C 2 H 3 O 2 ) 2 , ovalbumen, Na 2 ATP, yeast hexokinase). After a time course, the hexokinase reaction is stopped (slowed considerably) to minimize effects of contamination enzyme activities. The stopping agent used is lyxose, a nonphosphorylable analogue of glucose. The strong anionic charge of phosphate introduced through the hexokinase action results in binding (> 95%) of hexose-phosphate to anion-exchange resin. Sucrose remains unbound (> 95%) in solution. This batch ion-exchange is performed in microcentrifuge tubes to allow many samples to be processed simultaneously. Recovery of radiolabel in extracts is complete (99%), and determinations are repeatable (cv = 23%). This method for routinely separating and quantifying 14 C-hexose and 14 C-sucrose in plant tissue extracts can contribute to the economy and feasibility of studies of 14 C-photoassimilate partitioning to soluble sugars within and among plant tissues

Physiological and fermentation properties of Bacillus coagulans and a mutant lacking fermentative lactate dehydrogenase activity.

Science.gov (United States)

Su, Yue; Rhee, Mun Su; Ingram, Lonnie O; Shanmugam, K T

2011-03-01

Bacillus coagulans, a sporogenic lactic acid bacterium, grows optimally at 50-55 °C and produces lactic acid as the primary fermentation product from both hexoses and pentoses. The amount of fungal cellulases required for simultaneous saccharification and fermentation (SSF) at 55 °C was previously reported to be three to four times lower than for SSF at the optimum growth temperature for Saccharomyces cerevisiae of 35 °C. An ethanologenic B. coagulans is expected to lower the cellulase loading and production cost of cellulosic ethanol due to SSF at 55 °C. As a first step towards developing B. coagulans as an ethanologenic microbial biocatalyst, activity of the primary fermentation enzyme L-lactate dehydrogenase was removed by mutation (strain Suy27). Strain Suy27 produced ethanol as the main fermentation product from glucose during growth at pH 7.0 (0.33 g ethanol per g glucose fermented). Pyruvate dehydrogenase (PDH) and alcohol dehydrogenase (ADH) acting in series contributed to about 55% of the ethanol produced by this mutant while pyruvate formate lyase and ADH were responsible for the remainder. Due to the absence of PDH activity in B. coagulans during fermentative growth at pH 5.0, the l-ldh mutant failed to grow anaerobically at pH 5.0. Strain Suy27-13, a derivative of the l-ldh mutant strain Suy27, that produced PDH activity during anaerobic growth at pH 5.0 grew at this pH and also produced ethanol as the fermentation product (0.39 g per g glucose). These results show that construction of an ethanologenic B. coagulans requires optimal expression of PDH activity in addition to the removal of the LDH activity to support growth and ethanol production.

Detection of mono- and di-hexoses as metabolites of 4-bromoaniline using HPLC-TOF-MS/MS.

Science.gov (United States)

Major, H; Castro-Perez, J; Nicholson, J K; Wilson, I D

2003-08-01

1. The metabolic fate of 4-bromoaniline (4-BrA) was investigated in rat following intraperitoneal administration at 50 mg kg(-1) using HPLC-TOF-MS/MS. 2. The sensitivity provided by the use of TOF-MS/MS, aided by the distinctive isotope pattern resulting from the presence of the bromine substituent in the molecule, enabled the detection of many previously uncharacterized metabolites in the samples. 3. Several groups of minor metabolites were detected in the urine that corresponded to a number of isomeric hexose and di-hexose-containing conjugates (possibly glucosides and diglucosides) of 4-BrA. 4. As well as hexose and di-hexose conjugates of 4-BrA, several further groups of metabolites that also contained either a sulphamate or sulphate group in addition to the sugar moieties were also detected.

Application of rice rhizosphere microflora for hydrogen production from apple pomace

Energy Technology Data Exchange (ETDEWEB)

Doi, Tetsuya [Institute for Sustainable Agro-ecosystem Services (ISAS), Graduate School of Agriculture and Life Sciences, The University of Tokyo, Nishitokyo, Tokyo 188-0002 (Japan); Nishihara Environment Technology Inc., Tokyo 108-0023 (Japan); Matsumoto, Hisami [Nishihara Environment Technology Inc., Tokyo 108-0023 (Japan); Abe, Jun [AE-Bio, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan); Morita, Shigenori [Institute for Sustainable Agro-ecosystem Services (ISAS), Graduate School of Agriculture and Life Sciences, The University of Tokyo, Nishitokyo, Tokyo 188-0002 (Japan)

2010-07-15

The combination of substrate materials and bacteria is an important factor affecting conversion technology for biological hydrogen production. We performed anaerobic hydrogen fermentation of apple pomace wastes using rhizosphere bacterial microflora of rice as the parent inoculum. In the vial test, the optimal condition for hydrogen fermentation was initial pH 6.0, 35 C, and 73.4 g pomace per liter of medium (equivalent to 10 g-hexose/L). In the batch experiment (pH 6.0, temperature 35 C) the hydrogen yield reached 2.3 mol-H{sub 2}/mol-hexose. The time course of biogas production and PCR-DGGE analysis suggest that Clostridium spp. decomposed degradable carbohydrates rapidly and a part of the refractory carbohydrate (e.g. pectin) gradually in the apple pomace slurry. In addition to hydrogen, volatile fatty acids (VFAs) were produced in the anaerobic fermentation of apple pomace, which can be a substrate for methane fermentation. The rice rhizosphere can be a promising source of inoculum bacteria for hydrogen fermentation in combination with plant material waste like apple pomace. (author)

Effects of topical application of aqueous solutions of hexoses on epidermal permeability barrier recovery rate after barrier disruption.

Science.gov (United States)

Denda, Mitsuhiro

2011-11-01

Previous studies have suggested that hexose molecules influence the stability of phospholipid bilayers. Therefore, the effects of topical application of all 12 stereoisomers of dextro-hexose on the epidermal barrier recovery rate after barrier disruption were evaluated. Immediately after tape stripping, 0.1 m aqueous solution of each hexose was applied on hairless mouse skin. Among the eight dextro-aldohexoses, topical application of altose, idose, mannose and talose accelerated the barrier recovery, while allose, galactose, glucose and gulose had no effect. Among the four dextro-ketohexoses, psicose, fructose, sorbose and tagatose all accelerated the barrier recovery. As the effects of hexoses on the barrier recovery rate appeared within 1 h, the mechanism is unlikely to be genomic. Instead, these hexoses may influence phase transition of the lipid bilayers of lamellar bodies and cell membrane, a crucial step in epidermal permeability barrier homeostasis. © 2011 John Wiley & Sons A/S.

Quantification of total hexose on dry blood spot by tandem mass spectrometry.

Science.gov (United States)

Gong, Zhenhua; Tian, Guoli; Huang, Qiwei; Wang, Yanmin; Ge, Qingwei

2012-12-01

Because hypoglycemia and hyperglycemia are harmful and not always associated with overt clinical signs, it is necessary to have methods available to screen for glucose levels to detect hypoglycemia and diabetes as early as possible. A new method for such screening and the clinical determination of blood total hexose on a dry blood spot (DBS) using tandem mass spectrometry (MS/MS) was developed. The serum glucose controls and blood were prepared as DBS and then extracted into a methanol solution containing isotope-labeled internal standards. The methanolic extraction was subjected to HPLC, followed by MS/MS in positive ion mode. Multiple-reaction monitoring of m/z 203.1→23 was used to detect hexose, and m/z 209.0→23 was used for 13C6-D-glucose. The recoveries of blood glucose by MS/MS were 90%-102% with an R(2) value of 0.999 after linear regression (pblood total hexose in neonates aged 3-7 days (6.41±1.46 mmol/L) was lower than that in neonates aged 8-30 days (6.66±1.38 mmol/L), and it was lower in neonates than in children aged 1-72 months (7.19±1.87 mmol/L). Quantification of total hexose on a dry blood spot by MS/MS is accurate, reliable and feasible for screening and clinical tests. Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Improved bioethanol production using fusants of Saccharomyces cerevisiae and xylose-fermenting yeasts.

Science.gov (United States)

Kumari, Rajni; Pramanik, K

2012-06-01

The present research deals with the development of a hybrid yeast strain with the aim of converting pentose and hexose sugar components of lignocellulosic substrate to bioethanol by fermentation. Different fusant strains were obtained by fusing protoplasts of Saccharomyces cerevisiae and xylose-fermenting yeasts such as Pachysolen tannophilus, Candida shehatae and Pichia stipitis. The fusants were sorted by fluorescent-activated cell sorter and further confirmed by molecular characterization. The fusants were evaluated by fermentation of glucose-xylose mixture and the highest ethanol producing fusant was used for further study to ferment hydrolysates produced by acid pretreatment and enzymatic hydrolysis of cotton gin waste. Among the various fusant and parental strains used under present study, RPR39 was found to be stable and most efficient strain giving maximum ethanol concentration (76.8 ± 0.31 g L(-1)), ethanol productivity (1.06 g L(-1) h(-1)) and ethanol yield (0.458 g g(-1)) by fermentation of glucose-xylose mixture under test conditions. The fusant has also shown encouraging result in fermenting hydrolysates of cotton gin waste with ethanol concentration of 7.08 ± 0.142 g L(-1), ethanol yield of 0.44 g g(-1), productivity of 0.45 g L(-1) h(-1) and biomass yield of 0.40 g g(-1).

Microbiology and optimization of hydrogen fermentation and bioelectricity production

Energy Technology Data Exchange (ETDEWEB)

Makinen, A.

2013-11-01

This work investigated dark fermentative hydrogen (H{sub 2}) and bioelectricity production from carbohydrates. Meso- and thermophilic fermentative and mesophilic exoelectrogenic bacteria were enriched from different natural sources. The H{sub 2} production from different hexoses and pentoses, them main constituents of lignocellulose, was studied in batch assays. H{sub 2} production from xylose was examined in continuous stirred tank reactor (CSTR). Operational parameters for H{sub 2} production were optimized. Bioelectricity production was studied in microbial fuel cells and process parameters were optimized. Dynamics of microbial communities in H{sub 2} and bioelectricity production processes were determined. A novel thermophilic dark fermentative H{sub 2} producing bacterium, Thermovorax subterraneus, was enriched and isolated from geothermal underground mine. T. subterraneus had the optimum growth temperature of 72 deg C and the maximum H{sub 2} yield of 1.4 mol/mol glucose in batch assay. The main soluble fermentative end products of T. subterraneus were acetate and ethanol. Thermophilic dark fermentative mixed culture enriched from hot spring (Hisarlan, Turkey) had the maximum H{sub 2} yield of 1.7 mol/mol glucose. The optimal environmental parameters to maximize H{sub 2} yield were temperature 52 deg C, initial pH 6.5, 40 mg/L Fe{sup 2+}, 4.5 g/L yeast extract and glucose concentration of 4 g/L. Increasing the glucose concentration to 18 g/L increased the maximum H{sub 2} production rate to 56.2 mmol H{sub 2}/h/L. Environmental parameters had a significant effect on metabolic pathways of fermentation. Another hot spring (Hisarkoy, Turkey) enrichment culture was able to ferment different sugars to H{sub 2} favoring pentoses over hexoses. The best H{sub 2} yields in batch assays were obtained from pentoses: xylose, arabinose and ribose yielded 21, 15 and 8 % of the theoretical yield, respectively; whilst on glucose the yield was only 2 % of the theoretical

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.

Kinetics and mechanism of thermal degradation of pentose- and hexose-based carbohydrate polymers.

Science.gov (United States)

Akbar, Jamshed; Iqbal, Mohammad S; Massey, Shazma; Masih, Rashid

2012-10-15

This work aims at study of thermal degradation kinetics and mechanism of pentose- and hexose-based carbohydrate polymers isolated from Plantago ovata (PO), Salvia aegyptiaca (SA) and Ocimum basilicum (OB). The analysis was performed by isoconversional method. The materials exhibited mainly two-stage degradation. The weight loss at ambient-115°C characterized by low activation energy corresponds to loss of moisture. The kinetic triplets consisting of E, A and g(α) model of the materials were determined. The major degradation stage represents a loss of high boiling volatile components. This stage is exothermic in nature. Above 340°C complete degradation takes place leaving a residue of 10-15%. The master plots of g(α) function clearly differentiated the degradation mechanism of hexose-based OB and SA polymers and pentose-based PO polymer. The pentose-based carbohydrate polymer showed D(4) type and the hexose-based polymers showed A(4) type degradation mechanism. Copyright © 2012 Elsevier Ltd. All rights reserved.

Enhancement of Antioxidative and Intestinal Anti-inflammatory Activities of Glycated Milk Casein after Fermentation with Lactobacillus rhamnosus 4B15.

Science.gov (United States)

Oh, Nam Su; Joung, Jae Yeon; Lee, Ji Young; Kim, Younghoon; Kim, Sae Hun

2017-06-14

In this study, we investigated the glycoproteomics of glycated milk casein (GMC) and GMC fermented by Lactobacillus rhamnosus 4B15 (FGMC) and determined their biological implications. There was a significant increase in the antioxidative and anti-inflammatory activities of GMC with galactose, which were higher than those of GMC with glucose (GMC-glc). Furthermore, the fermentation of GMC by L. rhamnosus 4B15 synergistically enhanced the above activities compared to those of unfermented GMC. Especially, fermented GMC-glc (FGMC-glc) possessed remarkably improved reducing power and radical scavenging activities. Moreover, FGMC-glc ameliorated the inflammatory response and tight junction-related intestinal epithelial dysfunction. Additionally, hexose-derived glycation and modification sites in protein sequences of GMC were identified. In particular, glycosylation and sulfation of serine and threonine residues were observed, and distinct modification sites were detected after fermentation. Therefore, these results indicated that glycation-induced modification of casein and fermentation correlated strongly with the enhanced functional properties.

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

DEFF Research Database (Denmark)

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

2004-01-01

Lignocellulose hydrolysate is an abundant substrate for bioethanol production. The ideal microorganism for such a fermentation process should combine rapid and efficient conversion of the available carbon sources to ethanol with high tolerance to ethanol and to inhibitory components in the hydrol......Lignocellulose hydrolysate is an abundant substrate for bioethanol production. The ideal microorganism for such a fermentation process should combine rapid and efficient conversion of the available carbon sources to ethanol with high tolerance to ethanol and to inhibitory components...... in the hydrolysate. A particular biological problem are the pentoses, which are not naturally metabolized by the main industrial ethanol producer Saccharomyces cerevisiae. Several recombinant, mutated, and evolved xylose fermenting S. cerevisiae strains have been developed recently. We compare here the fermentation...

In vitro batch fecal fermentation comparison of gas and short-chain fatty acid production using "slowly fermentable" dietary fibers.

Science.gov (United States)

Kaur, Amandeep; Rose, Devin J; Rumpagaporn, Pinthip; Patterson, John A; Hamaker, Bruce R

2011-01-01

Sustained colonic fermentation supplies beneficial fermentative by-products to the distal colon, which is particularly prone to intestinal ailments. Blunted/delayed initial fermentation may also lead to less bloating. Previously, we reported that starch-entrapped alginate-based microspheres act as a slowly fermenting dietary fiber. This material was used in the present study to provide a benchmark to compare to other "slowly fermentable" fibers. Dietary fibers with previous reports of slow fermentation, namely, long-chain inulin, psyllium, alkali-soluble corn bran arabinoxylan, and long-chain β-glucan, as well as starch-entrapped microspheres were subjected to in vitro upper gastrointestinal digestion and human fecal fermentation and measured over 48 h for pH, gas, and short-chain fatty acids (SCFA). The resistant fraction of cooked and cooled potato starch was used as another form of fermentable starch and fructooligosaccharides (FOS) served as a fast fermenting control. Corn bran arabinoxylan and long-chain β-glucan initially appeared slower fermenting with comparatively low gas and SCFA production, but later fermented rapidly with little remaining in the final half of the fermentation period. Long-chain inulin and psyllium had slow and moderate, but incomplete, fermentation. The resistant fraction of cooked and cooled potato starch fermented rapidly and appeared similar to FOS. In conclusion, compared to the benchmark slowly fermentable starch-entrapped microspheres, a number of the purported slowly fermentable fibers fermented fairly rapidly overall and, of this group, only the starch-entrapped microspheres appreciably fermented in the second half of the fermentation period. Consumption of dietary fibers, particularly commercial prebiotics, leads to uncomfortable feelings of bloating and flatulence due to their rapid degradation in our large intestine. This article employs claimed potential slowly fermenting fibers and compares their fermentation rates

Rapid identification of Chinese Sauce liquor from different fermentation positions with FT-IR spectroscopy

Science.gov (United States)

Li, Changwen; Wei, Jiping; Zhou, Qun; Sun, Suqin

2008-07-01

FT-IR and two-dimensional correlation spectroscopy (2D-IR) technology were applied to discriminate Chinese Sauce liquor from different fermentation positions (top, middle and bottom of fermentation cellar) for the first time. The liquors at top, middle and bottom of fermentation cellar, possessed the characteristic peaks at 1731 cm -1, 1733 cm -1 and 1602 cm -1, respectively. In the 2D correlation infrared spectra, the differences were amplified. A strong auto-peak at 1725 cm -1 showed in the 2D spectra of the Top Liquor, which indicated that the liquor might contain some ester compounds. Different from Top Liquor, three auto-peaks at 1695, 1590 and 1480 cm -1 were identified in 2D spectra of Middle Liquor, which were the characteristic absorption of acid, lactate. In 2D spectra of Bottom Liquor, two auto-peaks at 1570 and 1485 cm -1 indicated that lactate was the major component. As a result, FT-IR and 2D-IR correlation spectra technology provided a rapid and effective method for the quality analysis of the Sauce liquor.

Rapid and efficient galactose fermentation by engineered Saccharomyces cerevisiae.

Science.gov (United States)

Quarterman, Josh; Skerker, Jeffrey M; Feng, Xueyang; Liu, Ian Y; Zhao, Huimin; Arkin, Adam P; Jin, Yong-Su

2016-07-10

In the important industrial yeast Saccharomyces cerevisiae, galactose metabolism requires energy production by respiration; therefore, this yeast cannot metabolize galactose under strict anaerobic conditions. While the respiratory dependence of galactose metabolism provides benefits in terms of cell growth and population stability, it is not advantageous for producing fuels and chemicals since a substantial fraction of consumed galactose is converted to carbon dioxide. In order to force S. cerevisiae to use galactose without respiration, a subunit (COX9) of a respiratory enzyme was deleted, but the resulting deletion mutant (Δcox9) was impaired in terms of galactose assimilation. Interestingly, after serial sub-cultures on galactose, the mutant evolved rapidly and was able to use galactose via fermentation only. The evolved strain (JQ-G1) produced ethanol from galactose with a 94% increase in yield and 6.9-fold improvement in specific productivity as compared to the wild-type strain. (13)C-metabolic flux analysis demonstrated a three-fold reduction in carbon flux through the TCA cycle of the evolved mutant with redirection of flux toward the fermentation pathway. Genome sequencing of the JQ-G1 strain revealed a loss of function mutation in a master negative regulator of the Leloir pathway (Gal80p). The mutation (Glu348*) in Gal80p was found to act synergistically with deletion of COX9 for efficient galactose fermentation, and thus the double deletion mutant Δcox9Δgal80 produced ethanol 2.4 times faster and with 35% higher yield than a single knockout mutant with deletion of GAL80 alone. When we introduced a functional COX9 cassette back into the JQ-G1 strain, the JQ-G1-COX9 strain showed a 33% reduction in specific galactose uptake rate and a 49% reduction in specific ethanol production rate as compared to JQ-G1. The wild-type strain was also subjected to serial sub-cultures on galactose but we failed to isolate a mutant capable of utilizing galactose without

Fermentation of hexoses and pentoses from hydrolyzed soybean hull into ethanol and xylitol by Candida guilliermondii BL 13

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F. da Cunha-Pereira

Full Text Available Abstract This work investigated the ability of a recently isolated strain of Candida guilliermondii to convert hexoses and pentoses obtained from acid-enzymatic soybean hull hydrolysates into ethanol and, in smaller amounts, into xylitol. Operational conditions and media formulation were optimized concerning ethanol production using experimental designs (Plackett-Burman and Central Composite Design. Results showed that C. guilliermondii BL 13 was capable of growing in non-supplemented, non-detoxified biomass hydrolysates, and the best culture conditions were determined to be 28 °C, pH 5.0, and 109 CFU mL-1 of inoculum size. Ethanol productivity reached 1.4 g L-1 h-1, and maximal yields of 0.41 g g-1 were obtained, representing 80.4 % of the expected theoretical yields, whereas small amounts of xylitol were also produced. These results suggest that C. guilliermondii BL13 is a potentially useful yeast strain to be applied in second-generation ethanol production from lignocellulosic biomass based on its natural capacity to metabolize C-5 and C-6 sugars.

Life cycle studies of the hexose transporter of Plasmodium species and genetic validation of their essentiality.

Science.gov (United States)

Slavic, Ksenija; Straschil, Ursula; Reininger, Luc; Doerig, Christian; Morin, Christophe; Tewari, Rita; Krishna, Sanjeev

2010-03-01

A Plasmodium falciparum hexose transporter (PfHT) has previously been shown to be a facilitative glucose and fructose transporter. Its expression in Xenopus laevis oocytes and the use of a glucose analogue inhibitor permitted chemical validation of PfHT as a novel drug target. Following recent re-annotations of the P. falciparum genome, other putative sugar transporters have been identified. To investigate further if PfHT is the key supplier of hexose to P. falciparum and to extend studies to different stages of Plasmodium spp., we functionally analysed the hexose transporters of both the human parasite P. falciparum and the rodent parasite Plasmodium berghei using gene targeting strategies. We show here the essential function of pfht for the erythrocytic parasite growth as it was not possible to knockout pfht unless the gene was complemented by an episomal construct. Also, we show that parasites are rescued from the toxic effect of a glucose analogue inhibitor when pfht is overexpressed in these transfectants. We found that the rodent malaria parasite orthologue, P. berghei hexose transporter (PbHT) gene, was similarly refractory to knockout attempts. However, using a single cross-over transfection strategy, we generated transgenic P. berghei parasites expressing a PbHT-GFP fusion protein suggesting that locus is amenable for gene targeting. Analysis of pbht-gfp transgenic parasites showed that PbHT is constitutively expressed through all the stages in the mosquito host in addition to asexual stages. These results provide genetic support for prioritizing PfHT as a target for novel antimalarials that can inhibit glucose uptake and kill parasites, as well as unveiling the expression of this hexose transporter in mosquito stages of the parasite, where it is also likely to be critical for survival.

Production of ethanol and feed by high dry matter hydrolysis and fermentation of palm kernel press cake.

Science.gov (United States)

Jørgensen, Henning; Sanadi, Anand R; Felby, Claus; Lange, Niels Erik Krebs; Fischer, Morten; Ernst, Steffen

2010-05-01

Palm kernel press cake (PKC) is a residue from palm oil extraction presently only used as a low protein feed supplement. PKC contains 50% fermentable hexose sugars present in the form of glucan and mainly galactomannan. This makes PKC an interesting feedstock for processing into bioethanol or in other biorefinery processes. Using a combination of mannanase, beta-mannosidase, and cellulases, it was possible without any pretreatment to hydrolyze PKC at solid concentrations of 35% dry matter with mannose yields up to 88% of theoretical. Fermentation was tested using Saccharomyces cerevisiae in both a separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) setup. The hydrolysates could readily be fermented without addition of nutrients and with average fermentation yields of 0.43 +/- 0.02 g/g based on consumed mannose and glucose. Employing SSF, final ethanol concentrations of 70 g/kg was achieved in 216 h, corresponding to an ethanol yield of 70% of theoretical or 200 g ethanol/kg PKC. Testing various enzyme mixtures revealed that including cellulases in combination with mannanases significantly improved ethanol yields. Processing PKC to ethanol resulted in a solid residue enriched in protein from 17% to 28%, a 70% increase, thereby potentially making a high-protein containing feed supplement.

Operation of a two-stage continuous fermentation process producing hydrogen and methane from artificial food wastes

Energy Technology Data Exchange (ETDEWEB)

Nagai, Kohki; Mizuno, Shiho; Umeda, Yoshito; Sakka, Makiko [Toho Gas Co., Ltd. (Japan); Osaka, Noriko [Tokyo Gas Co. Ltd. (Japan); Sakka, Kazuo [Mie Univ. (Japan)

2010-07-01

An anaerobic two-stage continuous fermentation process with combined thermophilic hydrogenogenic and methanogenic stages (two-stage fermentation process) was applied to artificial food wastes on a laboratory scale. In this report, organic loading rate (OLR) conditions for hydrogen fermentation were optimized before operating the two-stage fermentation process. The OLR was set at 11.2, 24.3, 35.2, 45.6, 56.1, and 67.3 g-COD{sub cr} L{sup -1} day{sup -1} with a temperature of 60 C, pH5.5 and 5.0% total solids. As a result, approximately 1.8-2.0 mol-H{sub 2} mol-hexose{sup -1} was obtained at the OLR of 11.2-56.1 g-COD{sub cr} L{sup -1} day{sup -1}. In contrast, it was inferred that the hydrogen yield at the OLR of 67.3 g-COD{sub cr} L{sup -1} day{sup -1} decreased because of an increase in lactate concentration in the culture medium. The performance of the two-stage fermentation process was also evaluated over three months. The hydraulic retention time (HRT) of methane fermentation was able to be shortened 5.0 days (under OLR 12.4 g-COD{sub cr} L{sup -1} day{sup -1} conditions) when the OLR of hydrogen fermentation was 44.0 g-COD{sub cr} L{sup -1} day{sup -1}, and the average gasification efficiency of the two-stage fermentation process was 81% at the time. (orig.)

Alcoholic fermentation of whey

Energy Technology Data Exchange (ETDEWEB)

Beach, A S; Holland, J W

1958-09-10

The lactose of whey and other milk products is rapidly fermented to ethanol by means of Candida pseudotropicalis strain XI. The fermentation is complete in about 12 hours and yields about 45% ethanol based on the weight of lactose. Conditions favoring the fermentation and inhibiting lactic acid production include pH 4.5, 30/sup 0/, and continuous aeration.

Hexose kinases and their role in sugar-sensing and plant development

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David eGranot

2013-03-01

Full Text Available Hexose sugars, such as glucose and fructose produced in plants, are ubiquitous in most organisms and are the origin of most of the organic matter found in nature. To be utilized, hexose sugars must first be phosphorylated. The central role of hexose-phosphorylating enzymes has attracted the attention of many researchers, leading to novel discoveries. Only two families of enzymes capable of phosphorylating glucose and fructose have been identified in plants; hexokinases (HXKs and fructokinases (FRKs. Intensive investigations of these two families in numerous plant species have yielded a wealth of knowledge regarding the genes number, enzymatic characterization, intracellular localization and developmental and physiological roles of several HXKs and FRKs. The emerging picture indicates that HXK and FRK enzymes found at specific intracellular locations play distinct roles in plant metabolism and development. Individual HXKs were shown for the first time to be dual-function enzymes - sensing sugar levels independent of their catalytic activity and also controlling gene expression and major developmental pathways, as well as hormonal interactions. FRK, on the other hand, seems to play a central metabolic role in vascular tissues, controlling the amounts of sugars allocated for vascular development. While a clearer picture of the roles of these two types of enzymes is emerging, many questions remain unsolved, such as the specific tissues and types of cells in which these enzymes function, the roles of individual HXK and FRK genes, and how these enzymes interact with hormones in the regulation of developmental processes. It is anticipated that ongoing efforts will broaden our knowledge of these important plant enzymes and their potential uses in the modification of plant traits.

Butyric acid fermentation from pretreated and hydrolyzed wheat straw by C.tyrobutyricum

DEFF Research Database (Denmark)

Baroi, George Nabin; Westermann, Peter; Gavala, Hariklia N.

and xylose at a concentration of 71,6±0,2 g/l and 55,4±0,2 g/l respectively, with TS content 20,87% (g/g). From an economical point of view, the conversion of both sugars is very important. In fact C.tyrobutyricum has the capability to convert both hexose and pentose sugars. Results from batch experiments......Butyric acid fermentation has long been discussed in the last decade due to the wide application of butyric acid in chemical, pharmaceutical and food industries. Among other microbial strains, C.tyrobutyricum was found interesting due to its higher yield (more than 93% of the theoretical yield...

Rapid discrimination of strain-dependent fermentation characteristics among Lactobacillus strains by NMR-based metabolomics of fermented vegetable juice.

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Satoru Tomita

Full Text Available In this study, we investigated the applicability of NMR-based metabolomics to discriminate strain-dependent fermentation characteristics of lactic acid bacteria (LAB, which are important microorganisms for fermented food production. To evaluate the discrimination capability, six type strains of Lactobacillus species and six additional L. brevis strains were used focusing on i the difference between homo- and hetero-lactic fermentative species and ii strain-dependent characteristics within L. brevis. Based on the differences in the metabolite profiles of fermented vegetable juices, non-targeted principal component analysis (PCA clearly separated the samples into those inoculated with homo- and hetero-lactic fermentative species. The separation was primarily explained by the different levels of dominant metabolites (lactic acid, acetic acid, ethanol, and mannitol. Orthogonal partial least squares discrimination analysis, based on a regions-of-interest (ROIs approach, revealed the contribution of low-abundance metabolites: acetoin, phenyllactic acid, p-hydroxyphenyllactic acid, glycerophosphocholine, and succinic acid for homolactic fermentation; and ornithine, tyramine, and γ-aminobutyric acid (GABA for heterolactic fermentation. Furthermore, ROIs-based PCA of seven L. brevis strains separated their strain-dependent fermentation characteristics primarily based on their ability to utilize sucrose and citric acid, and convert glutamic acid and tyrosine into GABA and tyramine, respectively. In conclusion, NMR metabolomics successfully discriminated the fermentation characteristics of the tested strains and provided further information on metabolites responsible for these characteristics, which may impact the taste, aroma, and functional properties of fermented foods.

Blocking hexose entry into glycolysis activates alternative metabolic conversion of these sugars and upregulates pentose metabolism in Aspergillus nidulans

Energy Technology Data Exchange (ETDEWEB)

Khosravi, Claire; Battaglia, Evy; Kun, Roland S.; Dalhuijsen, Sacha; Visser, Jaap; Aguilar-Pontes, Maria V.; Zhou, Miamiao; Heyman, Heino M.; Kim, Young-Mo; Baker, Scott E.; de Vries, Ronald P.

2018-03-22

Background: Plant biomass is the most abundant carbon source for many fungal species. In the biobased industry fungi are used to produce lignocellulolytic enzymes to degrade agricultural waste biomass. Here we evaluated if it would be possible to create an Aspergillus nidulans strain that releases but does not metabolize hexoses from plant biomass. For this purpose, metabolic mutants were generated that were impaired in glycolysis, by using hexokinase (hxkA) and glucokinase (glkA) negative strains. To prevent repression of enzyme production due to the hexose accumulation, strains were generated that combined these mutations with a deletion in creA, the repressor involved in regulating preferential use of different carbon catabolic pathways. Results: Phenotypic analysis revealed reduced growth for the hxkA1 glkA4 mutant on wheat bran. However, hexoses did not accumulate during growth of the mutants on wheat bran, suggesting that glucose metabolism is re-routed towards alternative carbon catabolic pathways. The creAΔ4 mutation in combination with preventing initial phosphorylation in glycolysis resulted in better growth than the hxkA/glkA mutant and an increased expression of pentose catabolic and pentose phosphate pathway genes. This indicates that the reduced ability to use hexoses as carbon sources created a shift towards the pentose fraction of wheat bran as a major carbon source to support growth. Conclusion: Blocking the direct entry of hexoses to glycolysis activates alternative metabolic conversion of these sugars in A. nidulans during growth on plant biomass, but also upregulates conversion of other sugars, such as pentoses.

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.

Differences between flocculating yeast and regular industrial yeast in transcription and metabolite profiling during ethanol fermentation

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Lili Li

2017-03-01

Full Text Available Objectives: To improve ethanolic fermentation performance of self-flocculating yeast, difference between a flocculating yeast strain and a regular industrial yeast strain was analyzed by transcriptional and metabolic approaches. Results: The number of down-regulated (industrial yeast YIC10 vs. flocculating yeast GIM2.71 and up-regulated genes were 4503 and 228, respectively. It is the economic regulation for YIC10 that non-essential genes were down-regulated, and cells put more “energy” into growth and ethanol production. Hexose transport and phosphorylation were not the limiting-steps in ethanol fermentation for GIM2.71 compared to YIC10, whereas the reaction of 1,3-disphosphoglycerate to 3-phosphoglycerate, the decarboxylation of pyruvate to acetaldehyde and its subsequent reduction to ethanol were the most limiting steps. GIM2.71 had stronger stress response than non-flocculating yeast and much more carbohydrate was distributed to other bypass, such as glycerol, acetate and trehalose synthesis. Conclusions: Differences between flocculating yeast and regular industrial yeast in transcription and metabolite profiling will provide clues for improving the fermentation performance of GIM2.71.

Hexose transporter mRNAs for GLUT4, GLUT5, and GLUT12 predominate in human muscle.

Science.gov (United States)

Stuart, Charles A; Yin, Deling; Howell, Mary E A; Dykes, Rhesa J; Laffan, John J; Ferrando, Arny A

2006-11-01

In the past few years, 8 additional members of the facilitative hexose transporter family have been identified, giving a total of 14 members of the SLC2A family of membrane-bound hexose transporters. To determine which of the new hexose transporters were expressed in muscle, mRNA concentrations of 11 glucose transporters (GLUTs) were quantified and compared. RNA from muscle from 10 normal volunteers was subjected to RT-PCR. Primers were designed that amplified 78- to 241-base fragments, and cDNA standards were cloned for GLUT1, GLUT2, GLUT3, GLUT4, GLUT5, GLUT6, GLUT8, GLUT9, GLUT10, GLUT11, GLUT12, and GAPDH. Seven of these eleven hexose transporters were detectable in normal human muscle. The rank order was GLUT4, GLUT5, GLUT12, GLUT8, GLUT11, GLUT3, and GLUT1, with corresponding concentrations of 404 +/- 49, 131 +/- 14, 33 +/- 4, 5.5 +/- 0.5, 4.1 +/- 0.4, 1.2 +/- .0.1, and 0.9 +/- 0.2 copies/ng RNA (means +/- SE), respectively, for the 10 subjects. Concentrations of mRNA for GLUT4, GLUT5, and GLUT12 were much higher than those for the remainder of the GLUTs and together accounted for 98% of the total GLUT isoform mRNA. Immunoblots of muscle homogenates verified that the respective proteins for GLUT4, GLUT5, and GLUT12 were present in normal human muscle. Immunofluorescent studies demonstrated that GLUT4 and GLUT12 were predominantly expressed in type I oxidative fibers; however, GLUT5 was expressed predominantly in type II (white) fibers.

A Hexose Transporter Homologue Controls Glucose Repression in the Methylotrophic Yeast Hansenula polymorpha

NARCIS (Netherlands)

Stasyk, Oleh V.; Stasyk, Olena G.; Komduur, Janet; Veenhuis, Marten; Cregg, James M.; Sibirny, Andrei A.

2004-01-01

Peroxisome biogenesis and synthesis of peroxisomal enzymes in the methylotrophic yeast Hansenula polymorpha are under the strict control of glucose repression. We identified an H. polymorpha glucose catabolite repression gene (HpGCR1) that encodes a hexose transporter homologue. Deficiency in GCR1

Rapid production of organic fertilizer by dynamic high-temperature aerobic fermentation (DHAF) of food waste.

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Jiang, Yang; Ju, Meiting; Li, Weizun; Ren, Qingbin; Liu, Le; Chen, Yu; Yang, Qian; Hou, Qidong; Liu, Yiliang

2015-12-01

Keep composting matrix in continuous collision and friction under a relatively high-temperature can significantly accelerate the progress of composting. A bioreactor was designed according to the novel process. Using this technology, organic fertilizer could be produced within 96h. The electric conductivity (EC) and pH value reached to a stable value of 2.35mS/cm and 7.7 after 96h of fermentation. The total carbon/total nitrogen (TC/TN) and dissolved carbon/dissolved nitrogen (DC/DN) ratio was decrease from 27.3 and 36.2 to 17.4 and 7.6 respectively. In contrast, it needed 24days to achieve the similar result in traditional static composting (TSC). Compost particles with different size were analyzed to explore the rapid degradation mechanism of food waste. The evidence of anaerobic fermentation was firstly discovered in aerobic composting. Copyright © 2015 Elsevier Ltd. All rights reserved.

(13)C metabolic flux analysis in neurons utilizing a model that accounts for hexose phosphate recycling within the pentose phosphate pathway.

Science.gov (United States)

Gebril, Hoda M; Avula, Bharathi; Wang, Yan-Hong; Khan, Ikhlas A; Jekabsons, Mika B

2016-02-01

Glycolysis, mitochondrial substrate oxidation, and the pentose phosphate pathway (PPP) are critical for neuronal bioenergetics and oxidation-reduction homeostasis, but quantitating their fluxes remains challenging, especially when processes such as hexose phosphate (i.e., glucose/fructose-6-phosphate) recycling in the PPP are considered. A hexose phosphate recycling model was developed which exploited the rates of glucose consumption, lactate production, and mitochondrial respiration to infer fluxes through the major glucose consuming pathways of adherent cerebellar granule neurons by replicating [(13)C]lactate labeling from metabolism of [1,2-(13)C2]glucose. Flux calculations were predicated on a steady-state system with reactions having known stoichiometries and carbon atom transitions. Non-oxidative PPP activity and consequent hexose phosphate recycling, as well as pyruvate production by cytoplasmic malic enzyme, were optimized by the model and found to account for 28 ± 2% and 7.7 ± 0.2% of hexose phosphate and pyruvate labeling, respectively. From the resulting fluxes, 52 ± 6% of glucose was metabolized by glycolysis, compared to 19 ± 2% by the combined oxidative/non-oxidative pentose cycle that allows for hexose phosphate recycling, and 29 ± 8% by the combined oxidative PPP/de novo nucleotide synthesis reactions. By extension, 62 ± 6% of glucose was converted to pyruvate, the metabolism of which resulted in 16 ± 1% of glucose oxidized by mitochondria and 46 ± 6% exported as lactate. The results indicate a surprisingly high proportion of glucose utilized by the pentose cycle and the reactions synthesizing nucleotides, and exported as lactate. While the in vitro conditions to which the neurons were exposed (high glucose, no lactate or other exogenous substrates) limit extrapolating these results to the in vivo state, the approach provides a means of assessing a number of metabolic fluxes within the context of hexose phosphate recycling in the PPP from a

High-rate fermentative hydrogen production from beverage wastewater

International Nuclear Information System (INIS)

Sivagurunathan, Periyasamy; Sen, Biswarup; Lin, Chiu-Yue

2015-01-01

Highlights: • Hybrid immobilized-bacterial cells show stable operation over 175 days. • Low HRT of 1.5 h shows peak hydrogen production rate of 55 L/L-d. • Electricity generation is 9024 kW-d from 55 L/L-d hydrogen using beverage wastewater. • Granular sludge formed only at 2–3 h HRT with presence of Selenomonas sp. - Abstract: Hydrogen production from beverage industry wastewater (20 g/L hexose equivalent ) using an immobilized cell reactor with a continuous mode of operation was studied at various hydraulic retention times (HRT, 8–1.5 h). Maximum hydrogen production rate (HPR) of 55 L/L-d was obtained at HRT 1.5 h (an organic loading of 320 g/L-d hexose equivalent ). This HPR value is much higher than those of other industrial wastewaters employed in fermentative hydrogen production. The cell biomass concentration peaked at 3 h HRT with a volatile suspended solids (VSS) concentration of 6.31 g/L (with presence of self-flocculating Selenomonas sp.), but it dropped to 3.54 gVSS/L at 1.5 h HRT. With the shortening of HRT, lactate concentration increased but the concentration of the dominant metabolite butyrate did not vary significantly. The Clostridium species dynamics was not significantly affected, but total microbial community structure changed with respect to HRT variation as evident from PCR–DGGE analyses. Analysis of energy production rate suggests that beverage wastewater is a high energy yielding feedstock, and can replace 24% of electricity consumption in a model beverage industry

Growth rate-regulated expression of the hexose transporter HXT5 in Saccharomyces cerevisiae

NARCIS (Netherlands)

Verwaal, René

2003-01-01

Glucose, which is the most preferred carbon source for the yeast Saccharomyces cerevisiae, is transported across the plasma membrane into cells by hexose transporter (Hxt) proteins. The Hxt proteins are encoded by a multigene family consisting of 20 members. It was shown previously that HXT1-4 and

Inter-Kingdom Modification of Metabolic Behavior: [GAR+] Prion Induction in Saccharomyces cerevisiae Mediated by Wine Ecosystem Bacteria

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Linda F Bisson

2016-11-01

Full Text Available The yeast Saccharomyces cerevisiae has evolved to dominate grape juice fermentation. A suite of cellular properties, rapid nutrient depletion, production of inhibitory compounds and the metabolic narrowing of the niche, all enable a minor resident of the initial population to dramatically increase its relative biomass in the ecosystem. This dominance of the grape juice environment is fueled by a rapid launch of glycolysis and energy generation mediated by transport of hexoses and an efficient coupling of transport and catabolism. Fermentation occurs in the presence of molecular oxygen as the choice between respiratory or fermentative growth is regulated by the availability of sugar a phenomenon known as glucose or catabolite repression. Induction of the GAR+ prion alters the expression of the major hexose transporter active under these conditions, Hxt3, reducing glycolytic capacity. Bacteria present in the grape juice ecosystem were able to induce the GAR+ prion in wine strains of S. cerevisiae. This induction reduced fermentation capacity but did not block it entirely. However, dominance factors such as the rapid depletion of amino acids and other nitrogen sources from the environment were impeded enabling greater access to these substrates for the bacteria. Bacteria associated with arrested commercial wine fermentations were able to induce the prion state, and yeast cells isolated from arrested commercial fermentations were found to be GAR+ thus confirming the ecological relevance of prion induction. Subsequent analyses demonstrated that the presence of environmental acetic acid could lead to GAR+ induction in yeast strains under certain conditions. The induction of the prion enabled yeast growth on non-preferred substrates, oxidation and reduction products of glucose and fructose, present as a consequence of bacterial energy production. In native ecosystems prion induction never exceeded roughly 50-60% of the population of yeast cells

Expression of a putative grapevine hexose transporter in tobacco alters morphogenesis and assimilate partitioning.

Science.gov (United States)

Leterrier, Marina; Atanassova, Rossitza; Laquitaine, Laurent; Gaillard, Cécile; Coutos-Thévenot, Pierre; Delrot, Serge

2003-04-01

Tobacco plants were transformed by leaf disc regeneration with the VvHT1 (Vitis vinifera hexose transporter 1) cDNA under the control of the constitutive CaMV 35S promoter in a sense or antisense orientation. Among the 20 sense plants and 10 antisense plants obtained, two sense plants showed a mutant phenotype when grown in vitro, with stunted growth and an increase in the (leaves+stem)/roots dry weight ratio. The rate of [(3)H]-glucose uptake in leaf discs from these plants was decreased to 25% of the value measured in control plants. The amount of VvHT1 transgene and of host monosaccharide transporter MST transcripts in the leaves were studied by RNA gel blot analysis. The VvHT1 transcripts were usually present, but the amount of MST transcripts was the lowest in the plants that exhibited the most marked phenotype. Although the phenotype was lost when the plants were transferred from in vitro to greenhouse conditions, it was found again in vitro in the progeny obtained by self-pollination or by back-cross. The data show that VvHT1 sense expression resulted in unidirectional post-transcriptional gene inactivation of MST in some of the transformants, with dramatic effects on growth. They provide the first example of plants modified for hexose transport by post-transcriptional gene silencing. Some of the antisense plants also showed reduced expression of MST, and decreased growth. These results indicate that, like the sucrose transporters, hexose transporters play an important role in assimilate transport and in morphogenesis.

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

Combined inactivation of the Clostridium cellulolyticum lactate and malate dehydrogenase genes substantially increases ethanol yield from cellulose and switchgrass fermentations

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Li Yongchao

2012-01-01

Full Text Available Abstract Background The model bacterium Clostridium cellulolyticum efficiently degrades crystalline cellulose and hemicellulose, using cellulosomes to degrade lignocellulosic biomass. Although it imports and ferments both pentose and hexose sugars to produce a mixture of ethanol, acetate, lactate, H2 and CO2, the proportion of ethanol is low, which impedes its use in consolidated bioprocessing for biofuels production. Therefore genetic engineering will likely be required to improve the ethanol yield. Plasmid transformation, random mutagenesis and heterologous expression systems have previously been developed for C. cellulolyticum, but targeted mutagenesis has not been reported for this organism, hindering genetic engineering. Results The first targeted gene inactivation system was developed for C. cellulolyticum, based on a mobile group II intron originating from the Lactococcus lactis L1.LtrB intron. This markerless mutagenesis system was used to disrupt both the paralogous L-lactate dehydrogenase (Ccel_2485; ldh and L-malate dehydrogenase (Ccel_0137; mdh genes, distinguishing the overlapping substrate specificities of these enzymes. Both mutations were then combined in a single strain, resulting in a substantial shift in fermentation toward ethanol production. This double mutant produced 8.5-times more ethanol than wild-type cells growing on crystalline cellulose. Ethanol constituted 93% of the major fermentation products, corresponding to a molar ratio of ethanol to organic acids of 15, versus 0.18 in wild-type cells. During growth on acid-pretreated switchgrass, the double mutant also produced four times as much ethanol as wild-type cells. Detailed metabolomic analyses identified increased flux through the oxidative branch of the mutant's tricarboxylic acid pathway. Conclusions The efficient intron-based gene inactivation system produced the first non-random, targeted mutations in C. cellulolyticum. As a key component of the genetic toolbox

Fermentative hydrogen production from liquid swine manure with glucose supplement using an anaerobic sequencing batch reactor

Science.gov (United States)

Wu, Xiao

2009-12-01

one, which contributed to 56-58% of the total soluble metabolite production, indicative of an acetic acid fermentation system, and acetate-to-butyrate ratio was found to be closely related to hydrogen yield. pH level influenced every aspect of the ASBR performance for hydrogen production. ASBR operation at five pHs ranging from 4.4 to 5.6 (4.4, 4.7, 5.0, 5.3, 5.6) showed distinct dynamic profiles of both biogas production and the changes of H2 and CH4 percentage in the biogas during a running period of 22 days. The H2 content in biogas, H 2 production rate and H2 yield were all pH-dependent, in the range of 5.1-36.9 %, 0.71-8.97 L/d and 0.12-1.50 mol-H2/mol-glucose, respectively, and maximum values for all three responses were simultaneously achieved at pH 5.0. Methanogens appeared to be significantly activated at pH of 5.3 or higher since significant CH4 evolution and concurrent reduction in H2 production was observed at pH 5.3 and 5.6. Acetate, propionate, butyrate, valerate, and ethanol were main aqueous products in all pH tests and their distribution was influenced by pH. Analysis of kinetic models developed from modified Gompertz equations for batch experiments showed that pH had a profound effect on all kinetic parameters for hydrogen production including hydrogen potential, maximum hydrogen production rate and the length of the lag phase, as well as the maximum substrate utilization rate. The low pH of 4.4 gave the highest hydrogen production potential but with the lowest hydrogen production rate. A contrast experiment was conducted with an initial pH of 5.3 but not controlled, came up with a rapid pH decline, leading to a low hexose degradation efficiency of 33.2% and a significantly suppressed H2 production, indicating the importance of pH control and the effect of pH on H2 production and substrate consumption. pH 5.0 was verified as the optimal for the proposed fermentation system by kinetic models. An extremely linear relationship (R2= 0.993) between the

Lactose fermentation by engineered Saccharomyces cerevisiae capable of fermenting cellobiose.

Science.gov (United States)

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

2016-09-20

Lactose is an inevitable byproduct of the dairy industry. In addition to cheese manufacturing, the growing Greek yogurt industry generates excess acid whey, which contains lactose. Therefore, rapid and efficient conversion of lactose to fuels and chemicals would be useful for recycling the otherwise harmful acid whey. Saccharomyces cerevisiae, a popular metabolic engineering host, cannot natively utilize lactose. However, we discovered that an engineered S. cerevisiae strain (EJ2) capable of fermenting cellobiose can also ferment lactose. This finding suggests that a cellobiose transporter (CDT-1) can transport lactose and a β-glucosidase (GH1-1) can hydrolyze lactose by acting as a β-galactosidase. While the lactose fermentation by the EJ2 strain was much slower than the cellobiose fermentation, a faster lactose-fermenting strain (EJ2e8) was obtained through serial subcultures on lactose. The EJ2e8 strain fermented lactose with a consumption rate of 2.16g/Lh. The improved lactose fermentation by the EJ2e8 strain was due to the increased copy number of cdt-1 and gh1-1 genes. Looking ahead, the EJ2e8 strain could be exploited for the production of other non-ethanol fuels and chemicals from lactose through further metabolic engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

Increased xylose affinity of Hxt2 through gene shuffling of hexose transporters in Saccharomyces cerevisiae

NARCIS (Netherlands)

Nijland, Jeroen G; Shin, Hyun Yong; de Waal, Paul P; Klaassen, Paul; Driessen, Arnold J M

AIMS: Optimizing D-xylose transport in Saccharomyces cerevisiae is essential for efficient bioethanol production from cellulosic materials. We have used a gene shuffling approach of hexose (Hxt) transporters in order to increase the affinity for D-xylose. METHODS AND RESULTS: Various libraries were

Biobutanol Production from Hexose and Pentose Sugars

NARCIS (Netherlands)

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

2014-01-01

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

Wet oxidation treatment of organic household waste enriched with wheat straw for simultaneous saccharification and fermentation into ethanol

DEFF Research Database (Denmark)

Lissens, G.; Klinke, H.B.; Verstraete, W.

2004-01-01

Organic municipal solid waste enriched with wheat straw was subjected to wet-oxidation as a pre-treatment for subsequent enzymatic conversion and fermentation into bio-ethanol. The effect of tempera (185-195degrees C), oxygen pressure (3-12) and sodium carbonate (0-2 g l(-1)) addition on enzymatic...... in the treated waste could be converted into respectively hexose and pentose sugars compared to 46% for cellulose and 36% for hemicellulose in the raw waste. For all wet oxidation conditions tested, total carbohydrate recoveries were high (> 89%) and 44-66% of the original lignin could be converted into non......-toxic carboxylic acids mainly (2.2-4.5 % on DS basis). Simultaneous saccharification and fermentation (SSF) of the treated waste at 10% DS by Saccharomyces cerevisae yielded average ethanol concentrations of 16.5 to 22 g l(-1) for enzyme loadings of 5 and 25 FPU g(-1) DS, respectively. The cellulose to ethanol...

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.

The Effect of Fungicide Residues and Yeast Assimilable Nitrogen on Fermentation Kinetics and H2S Production during Cider Fermentation

OpenAIRE

Boudreau IV, Thomas Francis

2016-01-01

The Virginia cider industry has grown rapidly in the past decade, and demands research-based recommendations for cider fermentation. This study evaluated relationships between the unique chemistry of apples and production of hydrogen sulfide (H2S) in cider fermentations. Yeast assimilable nitrogen (YAN) concentration and composition and residual fungicides influence H2S production by yeast during fermentation, but these factors have to date only been studied in wine grape fermentations. This ...

Biotechnological production of ethanol from renewable resources by Neurospora crassa: an alternative to conventional yeast fermentations?

Science.gov (United States)

Dogaris, Ioannis; Mamma, Diomi; Kekos, Dimitris

2013-02-01

Microbial production of ethanol might be a potential route to replace oil and chemical feedstocks. Bioethanol is by far the most common biofuel in use worldwide. Lignocellulosic biomass is the most promising renewable resource for fuel bioethanol production. Bioconversion of lignocellulosics to ethanol consists of four major unit operations: pretreatment, hydrolysis, fermentation, and product separation/distillation. Conventional bioethanol processes for lignocellulosics apply commercial fungal cellulase enzymes for biomass hydrolysis, followed by yeast fermentation of resulting glucose to ethanol. The fungus Neurospora crassa has been used extensively for genetic, biochemical, and molecular studies as a model organism. However, the strain's potential in biotechnological applications has not been widely investigated and discussed. The fungus N. crassa has the ability to synthesize and secrete all three enzyme types involved in cellulose hydrolysis as well as various enzymes for hemicellulose degradation. In addition, N. crassa has been reported to convert to ethanol hexose and pentose sugars, cellulose polymers, and agro-industrial residues. The combination of these characteristics makes N. crassa a promising alternative candidate for biotechnological production of ethanol from renewable resources. This review consists of an overview of the ethanol process from lignocellulosic biomass, followed by cellulases and hemicellulases production, ethanol fermentations of sugars and lignocellulosics, and industrial application potential of N. crassa.

Day-night changes of energy-rich compounds in crassulacean acid metabolism (CAM) species utilizing hexose and starch.

Science.gov (United States)

Chen, Li-Song; Nose, Akihiro

2004-09-01

Plants with crassulacean acid metabolism (CAM) can be divided into two groups according to the major carbohydrates used for malic acid synthesis, either polysaccharide (starch) or monosaccharide (hexose). This is related to the mechanism and affects energy metabolism in the two groups. In Kalanchoë pinnata and K. daigremontiana, which utilize starch, ATP-dependent phosphofructokinase (tonoplast inorganic pyrophosphatase) activity is greater than inorganic pyrophosphate-dependent phosphofructokinase (tonoplast adenosine triphosphatase) activity, but the reverse is the case in pineapple (Ananas comosus) utilizing hexose. To test the hypothesis that the energy metabolism of the two groups differs, day-night changes in the contents of ATP, ADP, AMP, inorganic phosphate (Pi), phosphoenolpyruvate (PEP) and inorganic pyrophosphate (PPi) in K. pinnata and K. daigremontiana leaves and in pineapple chlorenchyma were analysed. The contents of energy-rich compounds were measured spectrophotometrically in extracts of tissue sampled in the light and dark, using potted plants, kept for 15 d before the experiments in a growth chamber. In the three species, ATP content and adenylate energy charge (AEC) increased in the dark and decreased in the light, in contrast to ADP and AMP. Changes in ATP and AEC were greater in Kalanchoë leaves than in pineapple chlorenchyma. PPi content in the three species increased in the dark, but on illumination it decreased rapidly and substantially, remaining little changed through the rest of the light period. Pi content of Kalanchoë leaves did not change between dark and light, whereas Pi in pineapple chlorenchyma increased in the dark and decreased in the light, and the changes were far greater than in Kalanchoë leaves. Light-dark changes in PEP content in the three species were similar. These results corroborate our hypothesis that day-night changes in the contents of energy-rich compounds differ between CAM species and are related to the

Effects of insulin on hexose transport across blood-brain barrier in normoglycemia

International Nuclear Information System (INIS)

Namba, H.; Lucignani, G.; Nehlig, A.; Patlak, C.; Pettigrew, K.; Kennedy, C.; Sokoloff, L.

1987-01-01

The effects of insulin on 3-O-[ 14 C] methylglucose transport across the blood-brain barrier (BBB) were studied in conscious rats under steady-state normoglycemic conditions. The [ 14 C]methylglucose was infused intravenously at a constant rate, and animals were killed at various times between 5 and 30 min after the initiation of the infusion. The time course of the arterial plasma concentration of [ 14 C]methylglucose was determined in timed arterial blood samples taken during the infusion. Local cerebral tissue concentrations of [ 14 C]methylglucose at the time of killing were determined by quantitative autoradiography of brain sections. The rate constants for inward and outward transport of [ 14 C]methylglucose across the BBB, K 1 , and k 2 , respectively, were estimated by a least-squares, best-fit of a kinetic equation to the measured time courses of plasma and tissue concentrations. The equilibrium distribution ration, K 1 /k 2 , for [ 14 C]methylglucose in brain increased by ∼ 10-11% in the hyperinsulinemic animals. Because 3-O-[ 14 C]methylglucose shares the same carrier that transports glucose and other hexoses across the BBB, these results suggest that hyperinsulinemia decreases the rate constants for transport but increases the distribution space for hexoses in brain. These effects are, however, quite small and are probably minor or negligible when compared with the major effects of insulin in other tissues

Rapid quantitative detection of Lactobacillus sakei in meat and fermented sausages by real-time PCR.

Science.gov (United States)

Martín, Belén; Jofré, Anna; Garriga, Margarita; Pla, Maria; Aymerich, Teresa

2006-09-01

A quick and simple method for quantitative detection of Lactobacillus sakei in fermented sausages was successfully developed. It is based on Chelex-100-based DNA purification and real-time PCR enumeration using a TaqMan fluorescence probe. Primers and probes were designed in the L. sakei 16S-23S rRNA intergenic transcribed spacer region, and the assay was evaluated using L. sakei genomic DNA and an artificially inoculated sausage model. The detection limit of this technique was approximately 3 cells per reaction mixture using both purified DNA and the inoculated sausage model. The quantification limit was established at 30 cells per reaction mixture in both models. The assay was then applied to enumerate L. sakei in real samples, and the results were compared to the MRS agar count method followed by confirmation of the percentage of L. sakei colonies. The results obtained by real-time PCR were not statistically significantly different than those obtained by plate count on MRS agar (P > 0.05), showing a satisfactory agreement between both methods. Therefore, the real-time PCR assay developed can be considered a promising rapid alternative method for the quantification of L. sakei and evaluation of the implantation of starter strains of L. sakei in fermented sausages.

Response of microbial community of organic-matter-impoverished arable soil to long-term application of soil conditioner derived from dynamic rapid fermentation of food waste.

Science.gov (United States)

Hou, Jiaqi; Li, Mingxiao; Mao, Xuhui; Hao, Yan; Ding, Jie; Liu, Dongming; Xi, Beidou; Liu, Hongliang

2017-01-01

Rapid fermentation of food waste can be used to prepare soil conditioner. This process consumes less time and is more cost-effective than traditional preparation technology. However, the succession of the soil microbial community structure after long-term application of rapid fermentation-derived soil conditioners remains unclear. Herein, dynamic rapid fermentation (DRF) of food waste was performed to develop a soil conditioner and the successions and diversity of bacterial communities in an organic-matter-impoverished arable soil after six years of application of DRF-derived soil conditioner were investigated. Results showed that the treatment increased soil organic matter (SOM) accumulation and strawberry yield by 5.3 g/kg and 555.91 kg/ha, respectively. Proteobacteria, Actinobacteria, Acidobacteria, and Firmicutes became the dominant phyla, occupying 65.95%-77.52% of the bacterial sequences. Principal component analysis (PCA) results showed that the soil bacterial communities were largely influenced by the treatment. Redundancy analysis (RDA) results showed that the relative abundances of Gemmatimonadetes, Chloroflexi, Verrucomicrobia, Nitrospirae, and Firmicutes were significantly correlated with soil TC, TN, TP, NH4+-N, NO3--N, OM, and moisture. These communities were all distributed in the soil samples collected in the sixth year of application. Long-term treatment did not enhance the diversity of bacterial species but significantly altered the distribution of major functional bacterial communities in the soils. Application of DRF-derived soil conditioner could improve the soil quality and optimize the microbial community, ultimately enhancing fruit yields.

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

Directory of Open Access Journals (Sweden)

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.

Identification of Selective Inhibitors of the Plasmodium falciparum Hexose Transporter PfHT by Screening Focused Libraries of Anti-Malarial Compounds.

Directory of Open Access Journals (Sweden)

Diana Ortiz

Full Text Available Development of resistance against current antimalarial drugs necessitates the search for novel drugs that interact with different targets and have distinct mechanisms of action. Malaria parasites depend upon high levels of glucose uptake followed by inefficient metabolic utilization via the glycolytic pathway, and the Plasmodium falciparum hexose transporter PfHT, which mediates uptake of glucose, has thus been recognized as a promising drug target. This transporter is highly divergent from mammalian hexose transporters, and it appears to be a permease that is essential for parasite viability in intra-erythrocytic, mosquito, and liver stages of the parasite life cycle. An assay was developed that is appropriate for high throughput screening against PfHT based upon heterologous expression of PfHT in Leishmania mexicana parasites that are null mutants for their endogenous hexose transporters. Screening of two focused libraries of antimalarial compounds identified two such compounds that are high potency selective inhibitors of PfHT compared to human GLUT1. Additionally, 7 other compounds were identified that are lower potency and lower specificity PfHT inhibitors but might nonetheless serve as starting points for identification of analogs with more selective properties. These results further support the potential of PfHT as a novel drug target.

Day–Night Changes of Energy-rich Compounds in Crassulacean Acid Metabolism (CAM) Species Utilizing Hexose and Starch

Science.gov (United States)

CHEN, LI-SONG; NOSE, AKIHIRO

2004-01-01

• Background and Aims Plants with crassulacean acid metabolism (CAM) can be divided into two groups according to the major carbohydrates used for malic acid synthesis, either polysaccharide (starch) or monosaccharide (hexose). This is related to the mechanism and affects energy metabolism in the two groups. In Kalanchoë pinnata and K. daigremontiana, which utilize starch, ATP-dependent phosphofructokinase (tonoplast inorganic pyrophosphatase) activity is greater than inorganic pyrophosphate-dependent phosphofructokinase (tonoplast adenosine triphosphatase) activity, but the reverse is the case in pineapple (Ananas comosus) utilizing hexose. To test the hypothesis that the energy metabolism of the two groups differs, day-night changes in the contents of ATP, ADP, AMP, inorganic phosphate (Pi), phosphoenolpyruvate (PEP) and inorganic pyrophosphate (PPi) in K. pinnata and K. daigremontiana leaves and in pineapple chlorenchyma were analysed. • Methods The contents of energy-rich compounds were measured spectrophotometrically in extracts of tissue sampled in the light and dark, using potted plants, kept for 15 d before the experiments in a growth chamber. • Key Results In the three species, ATP content and adenylate energy charge (AEC) increased in the dark and decreased in the light, in contrast to ADP and AMP. Changes in ATP and AEC were greater in Kalanchoë leaves than in pineapple chlorenchyma. PPi content in the three species increased in the dark, but on illumination it decreased rapidly and substantially, remaining little changed through the rest of the light period. Pi content of Kalanchoë leaves did not change between dark and light, whereas Pi in pineapple chlorenchyma increased in the dark and decreased in the light, and the changes were far greater than in Kalanchoë leaves. Light-dark changes in PEP content in the three species were similar. • Conclusions These results corroborate our hypothesis that day–night changes in the contents of energy

Combined inactivation of the Clostridium cellulolyticum lactate and malate dehydrogenase genes substantially increases ethanol yield from cellulose and switchgrass fermentations

Energy Technology Data Exchange (ETDEWEB)

Li, Yongchao [ORNL; Tschaplinski, Timothy J [ORNL; Engle, Nancy L [ORNL; Hamilton, Choo Yieng [ORNL; Rodriguez, Jr., Miguel [ORNL; Liao, James C [ORNL; Schadt, Christopher Warren [ORNL; Guss, Adam M [ORNL; Yang, Yunfeng [ORNL; Graham, David E [ORNL

2012-01-01

Background: The model bacterium Clostridium cellulolyticum efficiently hydrolyzes crystalline cellulose and hemicellulose, using cellulosomes to degrade lignocellulosic biomass. Although it imports and ferments both pentose and hexose sugars to produce a mixture of ethanol, acetate, lactate, H2 and CO2, the proportion of ethanol is low, which impedes its use in consolidated bioprocessing for biofuels. Therefore genetic engineering will likely be required to improve the ethanol yield. Random mutagenesis, plasmid transformation, and heterologous expression systems have previously been developed for C. cellulolyticum, but targeted mutagenesis has not been reported for this organism. Results: The first targeted gene inactivation system was developed for C. cellulolyticum, based on a mobile group II intron originating from the Lactococcus lactis L1.LtrB intron. This markerless mutagenesis system was used to disrupt both the paralogous L-lactate dehydrogenase (Ccel_2485; ldh) and L-malate dehydrogenase (Ccel_0137; mdh) genes, distinguishing the overlapping substrate specificities of these enzymes. Both mutations were then combined in a single strain. This double mutant produced 8.5-times more ethanol than wild-type cells growing on crystalline cellulose. Ethanol constituted 93% of the major fermentation products (by molarity), corresponding to a molar ratio of ethanol to organic acids of 15, versus 0.18 in wild-type cells. During growth on acid-pretreated switchgrass, the double mutant also produced four-times as much ethanol as wild-type cells. Detailed metabolomic analyses identified increased flux through the oxidative branch of the mutant s TCA pathway. Conclusions: The efficient intron-based gene inactivation system produced the first gene-targeted mutations in C. cellulolyticum. As a key component of the genetic toolbox for this bacterium, markerless targeted mutagenesis enables functional genomic research in C. cellulolyticum and rapid genetic engineering to

Analysis of bacterial community during the fermentation of pulque, a traditional Mexican alcoholic beverage, using a polyphasic approach.

Science.gov (United States)

Escalante, Adelfo; Giles-Gómez, Martha; Hernández, Georgina; Córdova-Aguilar, María Soledad; López-Munguía, Agustín; Gosset, Guillermo; Bolívar, Francisco

2008-05-31

a 6-h fermentation, 83.27% of total sugars detected after inoculation were consumed (228.4 mM hexose equivalents) and a carbon (C) recovery of 66.18% in fermentation products was estimated. They were produced 284.4 mM C as ethanol, 71.5 mM C as acetic acid and 19 mM C as lactic acid, demonstrating the presence of homo- and heterofermentative, acetic and alcoholic metabolisms in the final product. It was also found, after hydrolysis, that the exopolysaccharide produced during the fermentation was mainly composed by fructose residues, probably inulin or levan.

Thermophilic fermentative hydrogen production by the newly isolated Thermoanaerobacterium thermosaccharolyticum PSU-2

DEFF Research Database (Denmark)

O-Thong, Sompong; Prasertsan, P.; Karakashev, Dimitar Borisov

2008-01-01

fermentation (24 h) and stopped at pH 4.5 due to the accumulation of organic acids. The maximum H(2) production yield and rate at sucrose concentration of 20 gl(-1), pH 6.25 and temperature 60 degrees C were 2.53 mol H(2) mol(-1) hexose and 12.12 mmol H(2) l(-1) h(-1), respectively. Organic nitrogen amended......A thermophilic H(2)-producing bacterial strain was isolated from a biohydrogen reactor fed with palm oil mill effluent (POME) and identified as Thermoanaerobacterium thermosaccharolyticum using 16S rRNA gene analysis. The isolated bacterium, designated as T thermosaccharolyticum PSU-2, showed...... a high yield and production rate of H(2). Temperature optimum, pH optimum and substrate utilization for H(2) production were investigated in batch conditions. All of tested substrate was utilized for H(2) production, while sucrose, xylose and starch were the preferred substrates. The strain produced H(2...

Regulation of photosynthesis by end-product accumulation in leaves of plants storing starch, sucrose, and hexose sugars.

Science.gov (United States)

Goldschmidt, E E; Huber, S C

1992-08-01

In the present study, leaves of different plant species were girdled by the hot wax collar method to prevent export of assimilates. Photosynthetic activity of girdled and control leaves was evaluated 3 to 7 days later by two methods: (a) carbon exchange rate (CER) of attached leaves was determined under ambient CO(2) concentrations using a closed gas system, and (b) maximum photosynthetic capacity (A(max)) was determined under 3% CO(2) with a leaf disc O(2) electrode. Starch, hexoses, and sucrose were determined enzymically. Typical starch storers like soybean (Glycine max L.) (up to 87.5 milligrams of starch per square decimeter in girdled leaves), cotton (Gossypium hirsutum L.), and cucumber (Cucumis sativus L.) responded to 7 days of girdling by increased (80-100%) stomatal resistance (r(s)) and decreased A(max) (>50%). On the other hand, spinach (Spinacia oleracea L.), a typical sucrose storer (up to 160 milligrams of sucrose per square decimeter in girdled leaves), showed only a slight reduction in CER and almost no change in A(max). Intermediate plants like tomato (Lycopersicon esculentum Mill.), sunflower (Helianthus annuus L.), broad bean (Vicia faba L.), bean (Phaseolus vulgaris L.), and pea (Pisum sativum L.), which upon girdling store both starch and sucrose, responded to the girdle by a considerable reduction in CER but only moderate inhibition of A(max), indicating that the observed reduction in CER was primarily a stomatal response. Both the wild-type tobacco (Nicotiana sylvestris) (which upon girdling stored starch and hexoses) and the starchless mutant (which stored only hexoses, up to 90 milligrams per square decimeter) showed 90 to 100% inhibition of CER and approximately 50% inhibition of A(max). In general, excised leaves (6 days) behaved like girdled leaves of the respective species, showing 50% reduction of A(max) in wild-type and starchless N. sylvestris but only slight decline of A(max) in spinach. The results of the present study

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

Lignocellulosic ethanol: Technology design and its impact on process efficiency.

Science.gov (United States)

Paulova, Leona; Patakova, Petra; Branska, Barbora; Rychtera, Mojmir; Melzoch, Karel

2015-11-01

This review provides current information on the production of ethanol from lignocellulosic biomass, with the main focus on relationships between process design and efficiency, expressed as ethanol concentration, yield and productivity. In spite of unquestionable advantages of lignocellulosic biomass as a feedstock for ethanol production (availability, price, non-competitiveness with food, waste material), many technological bottlenecks hinder its wide industrial application and competitiveness with 1st generation ethanol production. Among the main technological challenges are the recalcitrant structure of the material, and thus the need for extensive pretreatment (usually physico-chemical followed by enzymatic hydrolysis) to yield fermentable sugars, and a relatively low concentration of monosaccharides in the medium that hinder the achievement of ethanol concentrations comparable with those obtained using 1st generation feedstocks (e.g. corn or molasses). The presence of both pentose and hexose sugars in the fermentation broth, the price of cellulolytic enzymes, and the presence of toxic compounds that can inhibit cellulolytic enzymes and microbial producers of ethanol are major issues. In this review, different process configurations of the main technological steps (enzymatic hydrolysis, fermentation of hexose/and or pentose sugars) are discussed and their efficiencies are compared. The main features, benefits and drawbacks of simultaneous saccharification and fermentation (SSF), simultaneous saccharification and fermentation with delayed inoculation (dSSF), consolidated bioprocesses (CBP) combining production of cellulolytic enzymes, hydrolysis of biomass and fermentation into one step, together with an approach combining utilization of both pentose and hexose sugars are discussed and compared with separate hydrolysis and fermentation (SHF) processes. The impact of individual technological steps on final process efficiency is emphasized and the potential for use

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

DEFF Research Database (Denmark)

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

2002-01-01

% salt (w/w) as well as two high-salt batches, containing 9% and 11% salt. pH decreased rapidly from 6 to 4.5 in low-salt batches, whereas in high-salt batches, a slow or no decrease in pH was found. Lactic acid bacteria (LAB) and yeasts were isolated as the dominant microorganisms during fermentation....... LAB counts increased to 108-109 cfu g-1 and yeast counts to 107-5 x 107 cfu g-1 in all batches, except in the 11% salt batch, where counts were 1-2 log lower. Phenotypic tests, ITS-PCR, carbohydrate fermentations and 16S rRNA gene sequencing identified LAB isolates as Pediococcus pentosaceus......Plaa-som is a Thai fermented fish product prepared from snakehead fish, salt, palm syrup and sometimes roasted rice. We studied the effects of different salt concentrations on decrease in pH and on microflora composition during fermentation. Two low-salt batches were prepared, containing 6% and 7...

Aeration-Controlled Formation of Acid in Heterolactic Fermentations

DEFF Research Database (Denmark)

Adler-Nissen, Jens

1994-01-01

fermentation processes should be analyzed as fed-batch fermentations with oxygen as the limiting substrate. Addition of fructose in limited amounts leads to the formation of one half mole of acetic acid for each mole fructose, thus offering an alternative mechanism for controlling acetic acid formation.......Controlled aeration of Leuconostoc mesenteroides was studied as a possible mechanism for control of the formation of acetic acid, a metabolite of major influence on the taste of lactic fermented foods. Fermentations were carried out in small scale in a medium in which growth was limited...... by the buffer capacity only. Ethanol and acetic acid formed during the fermentation were analyzed by rapid head space gas chromatography, and the ratio of the molar concentrations of these two volatiles quantitatively predicted the balance between the formation of acetic acid and lactic acid. The oxygen...

Cell kinetics of differentiation of Na+-dependent hexose transport in a cultured renal epithelial cell line

International Nuclear Information System (INIS)

Cook, J.S.; Weiss, E.R.

1985-01-01

Fully differentiated cells of the renal proximal tubule have the capability of taking up hexoses across their apical borders by transport coupled to the Na + -electrochemical gradient. This property is also found in postconfluent cultures of the cloned cell line LLC-PK 1 , a morphologically polarized line of renal cells. Postconfluent cells develop the Na + -dependent capacity to transport hexoses at their apical surface. This function is not observable during the growth phase of the cultures. To analyze the developmental process at the cellular level a method has been derived to separate transporting cells, expressing the differentiated function, from nontransporting cells. The method is based on the swelling of the cells accompanying the uptake of the nonmetabolizable glucose analog alpha methylglucoside. The swollen cells have a lower buoyant density than the undifferentiated cells and may be separated from them on density gradients. Analysis of the distribution of cells on such gradients shows that after the cells reach confluence the undifferentiated subpopulation is recruited onto the differentiation pathway with a rate constant of 0.2 per day, that 5 to 7 days are required for a cell to traverse this pathway to the fully differentiated state, and that once the maximum uptake capacity is achieved the cells do not develop further

Automated identification of protein-ligand interaction features using Inductive Logic Programming: a hexose binding case study.

Science.gov (United States)

A Santos, Jose C; Nassif, Houssam; Page, David; Muggleton, Stephen H; E Sternberg, Michael J

2012-07-11

There is a need for automated methods to learn general features of the interactions of a ligand class with its diverse set of protein receptors. An appropriate machine learning approach is Inductive Logic Programming (ILP), which automatically generates comprehensible rules in addition to prediction. The development of ILP systems which can learn rules of the complexity required for studies on protein structure remains a challenge. In this work we use a new ILP system, ProGolem, and demonstrate its performance on learning features of hexose-protein interactions. The rules induced by ProGolem detect interactions mediated by aromatics and by planar-polar residues, in addition to less common features such as the aromatic sandwich. The rules also reveal a previously unreported dependency for residues cys and leu. They also specify interactions involving aromatic and hydrogen bonding residues. This paper shows that Inductive Logic Programming implemented in ProGolem can derive rules giving structural features of protein/ligand interactions. Several of these rules are consistent with descriptions in the literature. In addition to confirming literature results, ProGolem's model has a 10-fold cross-validated predictive accuracy that is superior, at the 95% confidence level, to another ILP system previously used to study protein/hexose interactions and is comparable with state-of-the-art statistical learners.

Saccharomyces cerevisiae and S. kudriavzevii Synthetic Wine Fermentation Performance Dissected by Predictive Modeling.

Science.gov (United States)

Henriques, David; Alonso-Del-Real, Javier; Querol, Amparo; Balsa-Canto, Eva

2018-01-01

Wineries face unprecedented challenges due to new market demands and climate change effects on wine quality. New yeast starters including non-conventional Saccharomyces species, such as S. kudriavzevii , may contribute to deal with some of these challenges. The design of new fermentations using non-conventional yeasts requires an improved understanding of the physiology and metabolism of these cells. Dynamic modeling brings the potential of exploring the most relevant mechanisms and designing optimal processes more systematically. In this work we explore mechanisms by means of a model selection, reduction and cross-validation pipeline which enables to dissect the most relevant fermentation features for the species under consideration, Saccharomyces cerevisiae T73 and Saccharomyces kudriavzevii CR85. The pipeline involved the comparison of a collection of models which incorporate several alternative mechanisms with emphasis on the inhibitory effects due to temperature and ethanol. We focused on defining a minimal model with the minimum number of parameters, to maximize the identifiability and the quality of cross-validation. The selected model was then used to highlight differences in behavior between species. The analysis of model parameters would indicate that the specific growth rate and the transport of hexoses at initial times are higher for S. cervisiae T73 while S. kudriavzevii CR85 diverts more flux for glycerol production and cellular maintenance. As a result, the fermentations with S. kudriavzevii CR85 are typically slower; produce less ethanol but higher glycerol. Finally, we also explored optimal initial inoculation and process temperature to find the best compromise between final product characteristics and fermentation duration. Results reveal that the production of glycerol is distinctive in S. kudriavzevii CR85, it was not possible to achieve the same production of glycerol with S. cervisiae T73 in any of the conditions tested. This result brings the

Saccharomyces cerevisiae and S. kudriavzevii Synthetic Wine Fermentation Performance Dissected by Predictive Modeling

Directory of Open Access Journals (Sweden)

David Henriques

2018-02-01

Full Text Available Wineries face unprecedented challenges due to new market demands and climate change effects on wine quality. New yeast starters including non-conventional Saccharomyces species, such as S. kudriavzevii, may contribute to deal with some of these challenges. The design of new fermentations using non-conventional yeasts requires an improved understanding of the physiology and metabolism of these cells. Dynamic modeling brings the potential of exploring the most relevant mechanisms and designing optimal processes more systematically. In this work we explore mechanisms by means of a model selection, reduction and cross-validation pipeline which enables to dissect the most relevant fermentation features for the species under consideration, Saccharomyces cerevisiae T73 and Saccharomyces kudriavzevii CR85. The pipeline involved the comparison of a collection of models which incorporate several alternative mechanisms with emphasis on the inhibitory effects due to temperature and ethanol. We focused on defining a minimal model with the minimum number of parameters, to maximize the identifiability and the quality of cross-validation. The selected model was then used to highlight differences in behavior between species. The analysis of model parameters would indicate that the specific growth rate and the transport of hexoses at initial times are higher for S. cervisiae T73 while S. kudriavzevii CR85 diverts more flux for glycerol production and cellular maintenance. As a result, the fermentations with S. kudriavzevii CR85 are typically slower; produce less ethanol but higher glycerol. Finally, we also explored optimal initial inoculation and process temperature to find the best compromise between final product characteristics and fermentation duration. Results reveal that the production of glycerol is distinctive in S. kudriavzevii CR85, it was not possible to achieve the same production of glycerol with S. cervisiae T73 in any of the conditions tested

Adsorptive detoxification of fermentation inhibitors in acid pretreated liquor using functionalized polymer designed by molecular simulation.

Science.gov (United States)

Devendra, Leena P; Pandey, Ashok

2017-11-01

Acid pretreatment is the most common method employed in the lignocellulosic biorefinery leading to the separation of pentose and hexose sugar. The liquor obtained after pretreatment (acid pretreatment liquor or APL) needs to be detoxified prior to fermentation. The aim of this study was to design functional groups on a polymer matrix which are selective in their interaction to inhibitors with little or no specificity to sugars. Molecular modeling was used as a tool to design a suitable adsorbent for selective adsorption of inhibitors from a complex mixture of APL. Phenyl glycine-p-sulfonic acid loaded on chloromethylated polystyrene polymer was designed as an adsorbent for selective interaction with inhibitors. Experimental verification of the selectivity was successfully achieved. The current study provides insights on the adsorptive separation processes at the molecular level by design of specific adsorbent which can be tailor made for the better selectivity of the desired component.

Rapid monitoring of glycerol in fermentation growth media: Facilitating crude glycerol bioprocess development.

Science.gov (United States)

Abad, Sergi; Pérez, Xavier; Planas, Antoni; Turon, Xavier

2014-04-01

Recently, the need for crude glycerol valorisation from the biodiesel industry has generated many studies for practical and economic applications. Amongst them, fermentations based on glycerol media for the production of high value metabolites are prominent applications. This has generated a need to develop analytical techniques which allow fast and simple glycerol monitoring during fermentation. The methodology should be fast and inexpensive to be adopted in research, as well as in industrial applications. In this study three different methods were analysed and compared: two common methodologies based on liquid chromatography and enzymatic kits, and the new method based on a DotBlot assay coupled with image analysis. The new methodology is faster and cheaper than the other conventional methods, with comparable performance. Good linearity, precision and accuracy were achieved in the lower range (10 or 15 g/L to depletion), the most common range of glycerol concentrations to monitor fermentations in terms of growth kinetics. Copyright © 2014 Elsevier B.V. All rights reserved.

Yeast phospholipase C is required for stability of casein kinase I Yck2p and expression of hexose transporters

Czech Academy of Sciences Publication Activity Database

Zhang, T.; Galdieri, L.; Hašek, Jiří; Vančura, A.

2017-01-01

Roč. 364, č. 22 (2017), č. článku fnx227. ISSN 0378-1097 R&D Projects: GA ČR(CZ) GA16-05497S Institutional support: RVO:61388971 Keywords : phospholipase C * casein kinase I * hexose transporters Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 1.765, year: 2016

Cell wall metabolism and hexose allocation contribute to biomass accumulation in high yielding extreme segregants of a Saccharum interspecific F2 population.

Science.gov (United States)

Wai, Ching Man; Zhang, Jisen; Jones, Tyler C; Nagai, Chifumi; Ming, Ray

2017-10-11

Sugarcane is an emerging dual-purpose biofuel crop for energy and sugar production, owing to its rapid growth rate, high sucrose storage in the stems, and high lignocellulosic yield. It has the highest biomass production reaching 1.9 billion tonnes in 2014 worldwide. To improve sugarcane biomass accumulation, we developed an interspecific cross between Saccharum officinarum 'LA Purple' and Saccharum robustum 'MOL5829'. Selected F1 individuals were self-pollinated to generate a transgressive F2 population with a wide range of biomass yield. Leaf and stem internodes of fourteen high biomass and eight low biomass F2 extreme segregants were used for RNA-seq to decipher the molecular mechanism of rapid plant growth and dry weight accumulation. Gene Ontology terms involved in cell wall metabolism and carbohydrate catabolism were enriched among 3274 differentially expressed genes between high and low biomass groups. Up-regulation of cellulose metabolism, pectin degradation and lignin biosynthesis genes were observed in the high biomass group, in conjunction with higher transcript levels of callose metabolic genes and the cell wall loosening enzyme expansin. Furthermore, UDP-glucose biosynthesis and sucrose conversion genes were differentially expressed between the two groups. A positive correlation between stem glucose, but not sucrose, levels and dry weight was detected. We thus postulated that the high biomass sugarcane plants rapidly convert sucrose to UDP-glucose, which is the building block of cell wall polymers and callose, in order to maintain the rapid plant growth. The gene interaction of cell wall metabolism, hexose allocation and cell division contributes to biomass yield.

Production of Biocellulosic Ethanol from Wheat Straw

Directory of Open Access Journals (Sweden)

Ismail

2012-01-01

Full Text Available Wheat straw is an abundant lignocellulosic feedstock in many parts of the world, and has been selected for producing ethanol in an economically feasible manner. It contains a mixture of sugars (hexoses and pentoses.Two-stage acid hydrolysis was carried out with concentrates of perchloric acid, using wheat straw. The hydrolysate was concentrated by vacuum evaporation to increase the concentration of fermentable sugars, and was detoxified by over-liming to decrease the concentration of fermentation inhibitors. After two-stage acid hydrolysis, the sugars and the inhibitors were measured. The ethanol yields obtained from by converting hexoses and pentoses in the hydrolysate with the co-culture of Saccharomyces cerevisiae and Pichia stipites were higher than the ethanol yields produced with a monoculture of S. cerevisiae. Various conditions for hysdrolysis and fermentation were investigated. The ethanol concentration was 11.42 g/l in 42 h of incubation, with a yield of 0.475 g/g, productivity of 0.272 gl ·h, and fermentation efficiency of 92.955 %, using a co-culture of Saccharomyces cerevisiae and Pichia stipites

Synthesis, characterization and biodistribution of technetium complexes (99Tc/99mTc) with 2-amino-2-deoxy-D-hexose oximes

International Nuclear Information System (INIS)

Steinmetz, H.J.

1993-05-01

In the present work, the synthesis and isolation of isomeric complexes of technetium ( 99 Tc/ 99m Tc) with the 2-amino-2-deoxy-D-hexoses D-glucose aminoxime, D-galactose aminoxime and D-mannose aminoxime, the characterization of the complexes as 99 Tc compounds, and bio-distribution studies on the analogous 99m Tc complexes have been untertaken. As a first step, the free ligands were synthesized and identified using elemental analysis, infra-red and nuclear magnetic resonance spectroscopy and FAB mass spectroscopy. In the bio-distribution studies on the 99m Tc complexes of D-glucose aminoxime and of D-galactose aminoxime in NMRI mice, significant short-term accumulation of 99m Tc activity in heart muscle could be detected, which may be attributed to a biochemical transport mechanism. Uptake in the lungs and the liver was found, but a more significant uptake was observed in the kidneys, where the complexes were rapidly secreted in proportion to their concentration in the blood plasma. (orig./BBR) [de

Continuous fermentative hydrogen production from coffee drink manufacturing wastewater by applying UASB reactor

Energy Technology Data Exchange (ETDEWEB)

Jung, Kyung-Won; Shin, Hang-Sik [Department of Civil and Environmental Engineering, KAIST, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Dong-Hoon [Department of Civil and Environmental Engineering, University of Windsor, 401 Sunset Ave., Essex Hall, Windsor, Ontario (Canada)

2010-12-15

The feasibility of continuous H{sub 2} production from coffee drink manufacturing wastewater (CDMW) was tested in two different types of reactors: a completely-stirred tank reactor (CSTR) and an up-flow anaerobic sludge blanket reactor (UASBr). While the performance in CSTR was limited, it was significantly enhanced in UASBr. The maximum H{sub 2} yield of 1.29 mol H{sub 2}/mol hexose{sub added} was achieved at HRT of 6 h in UASBr operation. Non-hydrogenic, lactic acid was the dominant in CSTR, while butyric and caproic acids in UASBr. As caproic acid is generated by consuming acetic and butyric acids, all of which are related to H{sub 2} production, the presence of caproic acid in the broth also indicates H{sub 2} production, yielding 1.33 mol H{sub 2}/glucose. It was speculated that the enhanced performance in UASBr was attributed to the high concentration of biomass over 60,000 mg VSS/L in the blanket zone, which provided insufficient substrate for indigenous lactic acid bacteria (LAB) to survive. The abundance of LAB in CDMW was confirmed by natural fermentation of CDMW. That is without the addition of external inoculum, CDMW was mainly fermented into lactic acid under mesophilic condition. For the first time ever, H{sub 2} producing granules (HPG) with diameters of 2.1 mm were successfully formed by using actual waste as a substrate. (author)

Novel Pathway for Alcoholic Fermentation of 8-Gluconolactone in the Yeast Saccharomyces bulderi

NARCIS (Netherlands)

Dijken, van J.P.; Tuijl, van A.; Luttik, M.A.H.; Middelhoven, W.J.; Pronk, J.T.

2002-01-01

Under anaerobic conditions, the yeast Saccharomyces bulderi rapidly ferments -gluconolactone to ethanol and carbon dioxide. We propose that a novel pathway for -gluconolactone fermentation operates in this yeast. In this pathway, -gluconolactone is first reduced to glucose via an NADPH-dependent

Fed-batch hydrolysate addition and cell separation by settling in high cell density lignocellulosic ethanol fermentations on AFEX™ corn stover in the Rapid Bioconversion with Integrated recycling Technology process.

Science.gov (United States)

Sarks, Cory; Jin, Mingjie; Balan, Venkatesh; Dale, Bruce E

2017-09-01

The Rapid Bioconversion with Integrated recycling Technology (RaBIT) process uses enzyme and yeast recycling to improve cellulosic ethanol production economics. The previous versions of the RaBIT process exhibited decreased xylose consumption using cell recycle for a variety of different micro-organisms. Process changes were tested in an attempt to eliminate the xylose consumption decrease. Three different RaBIT process changes were evaluated in this work including (1) shortening the fermentation time, (2) fed-batch hydrolysate addition, and (3) selective cell recycling using a settling method. Shorting the RaBIT fermentation process to 11 h and introducing fed-batch hydrolysate addition eliminated any xylose consumption decrease over ten fermentation cycles; otherwise, decreased xylose consumption was apparent by the third cell recycle event. However, partial removal of yeast cells during recycle was not economical when compared to recycling all yeast cells.

Dynamic modeling of lactic acid fermentation metabolism with Lactococcus lactis.

Science.gov (United States)

Oh, Euhlim; Lu, Mingshou; Park, Changhun; Park, Changhun; Oh, Han Bin; Lee, Sang Yup; Lee, Jinwon

2011-02-01

A dynamic model of lactic acid fermentation using Lactococcus lactis was constructed, and a metabolic flux analysis (MFA) and metabolic control analysis (MCA) were performed to reveal an intensive metabolic understanding of lactic acid bacteria (LAB). The parameter estimation was conducted with COPASI software to construct a more accurate metabolic model. The experimental data used in the parameter estimation were obtained from an LC-MS/ MS analysis and time-course simulation study. The MFA results were a reasonable explanation of the experimental data. Through the parameter estimation, the metabolic system of lactic acid bacteria can be thoroughly understood through comparisons with the original parameters. The coefficients derived from the MCA indicated that the reaction rate of L-lactate dehydrogenase was activated by fructose 1,6-bisphosphate and pyruvate, and pyruvate appeared to be a stronger activator of L-lactate dehydrogenase than fructose 1,6-bisphosphate. Additionally, pyruvate acted as an inhibitor to pyruvate kinase and the phosphotransferase system. Glucose 6-phosphate and phosphoenolpyruvate showed activation effects on pyruvate kinase. Hexose transporter was the strongest effector on the flux through L-lactate dehydrogenase. The concentration control coefficient (CCC) showed similar results to the flux control coefficient (FCC).

Automated identification of protein-ligand interaction features using Inductive Logic Programming: a hexose binding case study

Directory of Open Access Journals (Sweden)

A Santos Jose C

2012-07-01

Full Text Available Abstract Background There is a need for automated methods to learn general features of the interactions of a ligand class with its diverse set of protein receptors. An appropriate machine learning approach is Inductive Logic Programming (ILP, which automatically generates comprehensible rules in addition to prediction. The development of ILP systems which can learn rules of the complexity required for studies on protein structure remains a challenge. In this work we use a new ILP system, ProGolem, and demonstrate its performance on learning features of hexose-protein interactions. Results The rules induced by ProGolem detect interactions mediated by aromatics and by planar-polar residues, in addition to less common features such as the aromatic sandwich. The rules also reveal a previously unreported dependency for residues cys and leu. They also specify interactions involving aromatic and hydrogen bonding residues. This paper shows that Inductive Logic Programming implemented in ProGolem can derive rules giving structural features of protein/ligand interactions. Several of these rules are consistent with descriptions in the literature. Conclusions In addition to confirming literature results, ProGolem’s model has a 10-fold cross-validated predictive accuracy that is superior, at the 95% confidence level, to another ILP system previously used to study protein/hexose interactions and is comparable with state-of-the-art statistical learners.

Fermentation by butyl bacteria of the hydrolyzates of plant refuse in admixture with molasses

Energy Technology Data Exchange (ETDEWEB)

Nakhmanovich, B M; Lipshits, V V; Palovich, L A

1965-01-01

The husks of sunflower seeds or the stems of maize were hydrolyzed with 1.5 to 2.0% H/sub 2/SO/sub 4/ for 90 minutes at 1 to 1.6 atmosphere and 1 part of hydrolyzate was added to 3 parts of raw molasses at 80/sup 0/. Inversion of the sucrose content of the molasses occurred within 30 to 60 minutes, the hydrolyzate was neutralized to pH 6.5 with CaCO/sub 3/, and the CaSO/sub 4/ precipitated removed by pressure filtration through canvas. The filtered wort was sterilized for 10 to 13 minutes at 112/sup 0/, cooled, and added to a sterile solution of NH/sub 4/HSO/sub 4/-superphosphate, 0.1%, and yeast autolyzate, 0.03%. Fermentation of the pentose-hexose sugars was carried out at 37/sup 0/ using butyl bacteria (acetone-butanol process). Preliminary inversion of the molasses sucrose made it possible to increase the sugar content by 1 to 2% and the decrease the fermentation time from 65 to 75 to 50 to 55 hours, depending on the extent of inversion. This was important because of the poor invertase activity of the butyl bacteria. The total amount of acetone butanol and ethanol produced (31 to 37% on sugar) when using molasses so treated was up to 50% greater than when using untreated molasses. This increase was due to the greater synthesis of acetone and ethanol only, the amount of butanol remaining unchanged.

Acetone-butanol fermentation of blackstrap molasses. An effective factor of some symbiotic organisms against an abnormal fermentation

Energy Technology Data Exchange (ETDEWEB)

Shiga, A; Kinoshita, S; Okumura, T

1954-01-01

There were three types of abnormal fermentation in the industrial acetone-butanol fermentation of blackstrap molasses; one of them called B type, was characterized by the extremely prolonged acidity peak, and sluggishness experiments were carried out to find some symbiotic organisms among various aerobic bacteria and yeasts for several strains of Clostridium acetobutylicum. Torula utilis showed an outstanding effectiveness for a rapid completion of the fermentation, and the yields of solvents was much increased. Culture filtrate of T. utilis contained a soluble and thermolabile effective factor, and showed high invertase activity. A close relation was found between high yields of solvents and the degree of inversion of molasses medium. Thus, the effective factor against sluggishness was ascribed to the invertase activity of the yeast. Some inhibiting factors to invertase of C. acetobutylicum were presumed to be present in molasses as the principal cause of the sluggishness.

Characterisation of the Aspergillus nidulans frA1 mutant: hexose phosphorylation and apparent lack of involvement of hexokinase in glucose repression.

NARCIS (Netherlands)

Ruijter, G.J.G.; Panneman, H.; Broeck, van den H.C.; Bennett, J.M.; Visser, J.

1996-01-01

Hexose phosphorylation was studied in Aspergillus nidulans wild-type and in a fructose non-utilising mutant (frA). The data indicate the presence of at least one hexokinase and one glucokinase in wild-type A. nidulans, while the frA1 mutant lacks hexokinase activity. The A. nidulans gene encoding

Bioconversion of paper sludge to biofuel by simultaneous saccharification and fermentation using a cellulase of paper sludge origin and thermotolerant Saccharomyces cerevisiae TJ14

Directory of Open Access Journals (Sweden)

Harashima Satoshi

2011-09-01

Full Text Available Abstract Background Ethanol production from paper sludge (PS by simultaneous saccharification and fermentation (SSF is considered to be the most appropriate way to process PS, as it contains negligible lignin. In this study, SSF was conducted using a cellulase produced from PS by the hypercellulase producer, Acremonium cellulolyticus C-1 for PS saccharification, and a thermotolerant ethanol producer Saccharomyces cerevisiae TJ14 for ethanol production. Using cellulase of PS origin minimizes biofuel production costs, because the culture broth containing cellulase can be used directly. Results When 50 g PS organic material (PSOM/l was used in SSF, the ethanol yield based on PSOM was 23% (g ethanol/g PSOM and was two times higher than that obtained by a separate hydrolysis and fermentation process. Cellulase activity throughout SSF remained at around 60% of the initial activity. When 50 to 150 g PSOM/l was used in SSF, the ethanol yield was 21% to 23% (g ethanol/g PSOM at the 500 ml Erlenmeyer flask scale. Ethanol production and theoretical ethanol yield based on initial hexose was 40 g/l and 66.3% (g ethanol/g hexose at 80 h, respectively, when 161 g/l of PSOM, 15 filter paper units (FPU/g PSOM, and 20% inoculum were used for SSF, which was confirmed in the 2 l scale experiment. This indicates that PS is a good raw material for bioethanol production. Conclusions Ethanol concentration increased with increasing PSOM concentration. The ethanol yield was stable at PSOM concentrations of up to 150 g/l, but decreased at concentrations higher than 150 g/l because of mass transfer limitations. Based on a 2 l scale experiment, when 1,000 kg PS was used, 3,182 kFPU cellulase was produced from 134.7 kg PS. Produced cellulase was used for SSF with 865.3 kg PS and ethanol production was estimated to be 51.1 kg. Increasing the yeast inoculum or cellulase concentration did not significantly improve the ethanol yield or concentration.

A short review on SSF – an interesting process option for ethanol production from lignocellulosic feedstocks

Directory of Open Access Journals (Sweden)

Bertilsson Magnus

2008-05-01

Full Text Available Abstract Simultaneous saccharification and fermentation (SSF is one process option for production of ethanol from lignocellulose. The principal benefits of performing the enzymatic hydrolysis together with the fermentation, instead of in a separate step after the hydrolysis, are the reduced end-product inhibition of the enzymatic hydrolysis, and the reduced investment costs. The principal drawbacks, on the other hand, are the need to find favorable conditions (e.g. temperature and pH for both the enzymatic hydrolysis and the fermentation and the difficulty to recycle the fermenting organism and the enzymes. To satisfy the first requirement, the temperature is normally kept below 37°C, whereas the difficulty to recycle the yeast makes it beneficial to operate with a low yeast concentration and at a high solid loading. In this review, we make a brief overview of recent experimental work and development of SSF using lignocellulosic feedstocks. Significant progress has been made with respect to increasing the substrate loading, decreasing the yeast concentration and co-fermentation of both hexoses and pentoses during SSF. Presently, an SSF process for e.g. wheat straw hydrolyzate can be expected to give final ethanol concentrations close to 40 g L-1 with a yield based on total hexoses and pentoses higher than 70%.

Effect of fermentation and sterilization on anthocyanins in blueberry.

Science.gov (United States)

Nie, Qixing; Feng, Lei; Hu, Jielun; Wang, Sunan; Chen, Haihong; Huang, Xiaojun; Nie, Shaoping; Xiong, Tao; Xie, Mingyong

2017-03-01

Blueberry products have various health benefits due to their high content of dietary anthocyanins. The aim of this study was to investigate the impact of fermentation and sterilization on total anthocyanin content, composition and some quality attributes of blueberry puree. The blueberry puree used here was fermented for 40 h at 37 °C by Lactobacillus after sterilization. The method of ultra-performance liquid chromatography-mass spectrometry was optimized for the rapid analysis of anthocyanins. Quality attributes including pH, color, total soluble solids and viscosity were measured. A total of 21 anthocyanins and five anthocyanidins were quantified by ultra-performance liquid chromatography. Fermented blueberry had reduced total anthocyanin content (29%) and levels of individual anthocyanins compared with fresh blueberry. Total anthocyanin content was decreased 46% by sterilization, and different degradation behavior of individual anthocyanin was appeared between fermented and sterilized-fermented blueberry puree. Fermentation and sterilization decreased the total soluble solids and pH and changed color parameters, while minimally influencing viscosity. The loss of total anthocyanin content by fermentation was related to the unstable structure of blueberry anthocyanins. Anthocyanins are sensitive to temperature (>80 °C), and degradation of anthocyanins by sterilization in blueberry should be considered in the fermentation procedure. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

The effect of kefir starter on Thai fermented sausage product

Directory of Open Access Journals (Sweden)

Marisa Jatupornpipat

2007-07-01

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

Metabolic evolution of Escherichia coli strains that produce organic acids

Science.gov (United States)

Grabar, Tammy; Gong, Wei; Yocum, R Rogers

2014-10-28

This invention relates to the metabolic evolution of a microbial organism previously optimized for producing an organic acid in commercially significant quantities under fermentative conditions using a hexose sugar as sole source of carbon in a minimal mineral medium. As a result of this metabolic evolution, the microbial organism acquires the ability to use pentose sugars derived from cellulosic materials for its growth while retaining the original growth kinetics, the rate of organic acid production and the ability to use hexose sugars as a source of carbon. This invention also discloses the genetic change in the microorganism that confers the ability to use both the hexose and pentose sugars simultaneously in the production of commercially significant quantities of organic acids.

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).

Fragmentation Pathways of Lithiated Hexose Monosaccharides

Science.gov (United States)

Abutokaikah, Maha T.; Frye, Joseph W.; Tschampel, John; Rabus, Jordan M.; Bythell, Benjamin J.

2018-05-01

We characterize the primary fragmentation reactions of three isomeric lithiated D-hexose sugars (glucose, galactose, and mannose) utilizing tandem mass spectrometry, regiospecific labeling, and theory. We provide evidence that these three isomers populate similar fragmentation pathways to produce the abundant cross-ring cleavage peaks (0,2A1 and 0,3A1). These pathways are highly consistent with the prior literature (Hofmeister et al. J. Am. Chem. Soc. 113, 5964-5970, 1991, Bythell et al. J. Am. Soc. Mass Spectrom. 28, 688-703, 2017, Rabus et al. Phys. Chem. Chem. Phys. 19, 25643-25652, 2017) and the present labeling data. However, the structure-specific energetics and rate-determining steps of these reactions differ as a function of precursor sugar and anomeric configuration. The lowest energy water loss pathways involve loss of the anomeric oxygen to furnish B1 ions. For glucose and galactose, the lithiated α-anomers generate ketone structures at C2 in a concerted reaction involving a 1,2-migration of the C2-H to the anomeric carbon (C1). In contrast, the β-anomers are predicted to form 1,3-anhydroglucose/galactose B1 ion structures. Initiation of the water loss reactions from each anomeric configuration requires distinct reactive conformers, resulting in different product ion structures. Inversion of the stereochemistry at C2 has marked consequences. Both lithiated mannose forms expel water to form 1,2-anhydromannose B1 ions with the newly formed epoxide group above the ring. Additionally, provided water loss is not instantaneous, the α-anomer can also isomerize to generate a ketone structure at C2 in a concerted reaction involving a 1,2-migration of the C2-H to C1. This product is indistinguishable to that from α-glucose. The energetics and interplay of these pathways are discussed. [Figure not available: see fulltext.

Hydrogen production from carrot pulp by the extreme thermophiles Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana

Energy Technology Data Exchange (ETDEWEB)

Vrije, Truus de; Budde, Miriam A.W.; Lips, Steef J.; Bakker, Robert R.; Mars, Astrid E.; Claassen, Pieternel A.M. [Wageningen UR, Food and Biobased Research, P.O. Box 17, 6700 AA Wageningen (Netherlands)

2010-12-15

Hydrogen was produced from carrot pulp hydrolysate, untreated carrot pulp and (mixtures of) glucose and fructose by the extreme thermophiles Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana in pH-controlled bioreactors. Carrot pulp hydrolysate was obtained after enzymatic hydrolysis of the polysaccharide fraction in carrot pulp. The main sugars in the hydrolysate were glucose, fructose, and sucrose. In fermentations with glucose hydrogen yields and productivities were similar for both strains. With fructose the hydrogen yield of C. saccharolyticus was reduced which might be related to uptake of glucose and fructose by different types of transport systems. With T. neapolitana the fructose consumption rate and consequently the hydrogen productivity were low. The hydrogen yields of both thermophiles were 2.7-2.8 mol H{sub 2}/mol hexose with 10 g/L sugars from carrot pulp hydrolysate. With 20 g/L sugars the yield of T. neapolitana was 2.4 mol H{sub 2}/mol hexose while the yield of C. saccharolyticus was reduced to 1.3 mol H{sub 2}/mol hexose due to high lactate production in the stationary growth phase. C. saccharolyticus was able to grow on carrot pulp and utilized soluble sugars and, after adaptation, pectin and some (hemi)cellulose. No growth was observed with T. neapolitana when using carrot pulp in agitated fermentations. Enzymatic hydrolysis of the polysaccharide fraction prior to fermentation increased the hydrogen yield with almost 10% to 2.3 g/kg of hydrolyzed carrot pulp. (author)

Yeast Population Dynamics in Spontaneous and Inoculated Alcoholic Fermentations of Zametovka Must

Directory of Open Access Journals (Sweden)

Franc Cus

2002-01-01

Full Text Available Inoculated fermentations, which are more rapid and more reliable than spontaneous fermentations, and assure predictable wine quality, are nowadays prevalent in Slovenia’s large-scale wine production. However, spontaneous fermentation strengthens local characteristics of wine and offers opportunities for technological innovation. In the 1999 vintage, spontaneous and inoculated fermentations of Zametovka (Vitis vinifera grape must were studied. Zametovka is the main red variety in production of traditional Slovene red blend wine, Cvicek. The diversity of yeast species and strains in both of the investigated fermentations was determined by molecular and traditional identification methods. The outset of alcoholic fermentation, yeast growth kinetics, and yeast population dynamics presents the main differences between the examined fermentations. Yeast population diversity was higher in the spontaneous process. Dominant yeast isolates from spontaneous fermentation were identified as Candida stellata, Hanseniaspora uvarum and Saccharomyces cerevisiae; whereas Saccharomyces bayanus, Pichia kluyveri, Pichia membranifaciens and Torulaspora delbrueckiim were found less frequently. Dominant species in the inoculated fermentation was Saccharomyces cerevisiae; other species found in smaller numbers were Candida stellata, Hanseniaspora uvarum and Debaryomyces hansenii var. hansenii. Using PFGE, we were able to distinguish among 15 different Saccharomyces cerevisiae strains and three different Saccharomyces bayanus strains isolated from spontaneous fermentation, whereas, in the case of inoculated fermentation, only two Saccharomyces cerevisiae strains were found. Their chromosomal patterns coincide with the chromosomal patterns of the starter culture strains.

Xylose-fermenting Pichia stipitis by genome shuffling for improved ethanol production.

Science.gov (United States)

Shi, Jun; Zhang, Min; Zhang, Libin; Wang, Pin; Jiang, Li; Deng, Huiping

2014-03-01

Xylose fermentation is necessary for the bioconversion of lignocellulose to ethanol as fuel, but wild-type Saccharomyces cerevisiae strains cannot fully metabolize xylose. Several efforts have been made to obtain microbial strains with enhanced xylose fermentation. However, xylose fermentation remains a serious challenge because of the complexity of lignocellulosic biomass hydrolysates. Genome shuffling has been widely used for the rapid improvement of industrially important microbial strains. After two rounds of genome shuffling, a genetically stable, high-ethanol-producing strain was obtained. Designated as TJ2-3, this strain could ferment xylose and produce 1.5 times more ethanol than wild-type Pichia stipitis after fermentation for 96 h. The acridine orange and propidium iodide uptake assays showed that the maintenance of yeast cell membrane integrity is important for ethanol fermentation. This study highlights the importance of genome shuffling in P. stipitis as an effective method for enhancing the productivity of industrial strains. © 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Rapid analysis of formic acid, acetic acid, and furfural in pretreated wheat straw hydrolysates and ethanol in a bioethanol fermentation using atmospheric pressure chemical ionisation mass spectrometry

Directory of Open Access Journals (Sweden)

Smart Katherine A

2011-09-01

Full Text Available Abstract Atmospheric pressure chemical ionisation mass spectrometry (APCI-MS offers advantages as a rapid analytical technique for the quantification of three biomass degradation products (acetic acid, formic acid and furfural within pretreated wheat straw hydrolysates and the analysis of ethanol during fermentation. The data we obtained using APCI-MS correlated significantly with high-performance liquid chromatography analysis whilst offering the analyst minimal sample preparation and faster sample throughput.

Rapid ion-pair liquid chromatographic method for the determination of fenbendazole marker residue in fermented dairy products.

Science.gov (United States)

Vousdouka, Venetia I; Papapanagiotou, Elias P; Angelidis, Apostolos S; Fletouris, Dimitrios J

2017-04-15

A simple, rapid and sensitive liquid chromatographic method that allows for the quantitative determination of fenbendazole residues in fermented dairy products is described. Samples were extracted with a mixture of acetonitrile-phosphoric acid and the extracts were defatted with hexane to be further partitioned into ethyl acetate. The organic layer was evaporated to dryness and the residue was reconstituted in mobile phase. Separation of fenbendazole and its sulphoxide, sulphone, and p-hydroxylated metabolites was carried out isocratically with a mobile phase containing both positively and negatively charged pairing ions. Overall recoveries ranged from 79.8 to 88.8%, while precision data, based on within and between days variations, suggested an overall relative standard deviation of 6.3-11.0%. The detection and quantification limits were lower than 9 and 21μg/kg, respectively. The method has been successfully applied to quantitate fenbendazole residues in Feta cheese and yoghurt made from spiked and incurred ovine milk. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of inulin chain length on fermentation by equine fecal bacteria and Streptococcus bovis in vitro

Science.gov (United States)

The ingestion of large quantities of rapidly fermentable carbohydrates (e.g. fructans) from pasture has been associated with the development of laminitis. Fructans are poorly degraded by mammalian enzymes and, therefore, are able to reach the hindgut. The fermentation of fructans can lead to the ove...

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...

Production of hydrogen from fermentation of pina agroindustrial waste

International Nuclear Information System (INIS)

Montoya Perez, Luisa

2012-01-01

The performance of biohydrogen production was assesed a laboratory level, by anaerobic fermentation using agroindustrial residue of pineapple heart and employing microorganisms own of sludges from the bottom of an anaerobic digester belonging to a wastewater treatment plant from a seafood processor. Residue of pineapple heart was characterized physicochemically. The amounts were quantified: moisture, ashes, crude fiber, glucose, reducing sugars, hydrogen potential, soluble solids (Brix grades), boron, nitrogen, phosphorus, calcium, magnesium, potassium, sulfur, zinc, iron, copper and manganese. Per gram of pineapple heart is obtained 0,113 g of reducing sugars and 0,0114 g of glucose, which has made it a carbohydrate rich material that could ferment and produce hydrogen or other metabolites of commercial interest. A maximum yield was obtained of 0,0484 mol H 2 / mol of glucose consumed with a hydrogen maximum output of 1,260 mmol, at a maximum production rate of 0.070 mmol/h with a time lag in the production of hydrogen to 7,833 h under the following conditions: initial pH of 5,5, substrate initial concentration of 5 g/L and using a medium of mineral formulation based on sodium, calcium, iodine, zinc, nickel and molybdenum, in a container 125 mL where was consumed 88,4% of the initial glucose. A maximum yield of 1,541 mol H 2 / mol of consumed glucose was obtained, in a fermentation time of 30 h, with a maximum hydrogen production of 41,227 mmol, at a maximum production rate of 6,740 mmol/h with a lag time in the production of hydrogen for 16 h, under the following conditions: initial pH of 5,5, substrate initial concentration of 5 g/L and using a middle of mineral formulation based on sodium, calcium, iodine, zinc, nickel and molybdenum in a fermentor of 5 L where 96,39% was consumed of the initial glucose. The maximum yield from 1,541 mol H 2 / mol of glucose consumed has corresponded to 38% of the target value of the United States Department of Energy equivalent

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

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E. V. Greek

2013-04-01

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

Uptake of 13C-glucose by cell suspensions of carrot (Daucus carota) measured by in vivo NMR: Cycling of triose, pentose- and hexose-phosphates

NARCIS (Netherlands)

Krook, J.; Vreugdenhil, D.; Dijkema, C.; Plas, van der L.H.W.

2000-01-01

After a lag phase of 2 days, batch-grown cells of carrot (Daucus carota L.) cv. Flakkese entered the exponential growth phase and started to accumulate sucrose and hexoses. Short-term feeding 13C-glucose in this period resulted in only minor labelling of sucrose or fructose. CO2 production from

Optimization of Fermentation Conditions for the Production of Bacteriocin Fermentate

Science.gov (United States)

2015-03-30

FERMENTATION CONDITIONS FOR THE PRODUCTION OF BACTERIOCIN “ FERMENTATE ” by Anthony Sikes Wayne Muller and Claire Lee March 2015...From - To) October 2010 – November 2013 4. TITLE AND SUBTITLE OPTIMIZATION OF FERMENTATION CONDITIONS FOR THE PRODUCTION OF BACTERIOCIN “ FERMENTATE ...nisin and pediocin. Whey + yeast extract was the best performing whey fermentation media. The nisin producer strain Lactococcus. lactis ssp. lactis was

Biogasification of solid wastes by two-phase anaerobic fermentation

International Nuclear Information System (INIS)

Ghosh, S.; Vieitez, E.R.; Liu, T.; Kato, Y.

1997-01-01

Municipal, industrial and agricultural solid wastes, and biomass deposits, cause large-scale pollution of land and water. Gaseous products of waste decomposition pollute the air and contribute to global warming. This paper describes the development of a two-phase fermentation system that alleviates methanogenic inhibition encountered with high-solids feed, accelerates methane fermentation of the solid bed, and captures methane (renewable energy) for captive use to reduce global warming. The innovative system consisted of a solid bed reactor packed with simulated solid waste at a density of 160 kg/m 3 and operated with recirculation of the percolated culture (bioleachate) through the bed. A rapid onset of solids hydrolysis, acidification, denitrification and hydrogen gas formation was observed under these operating conditions. However, these fermentative reactions stopped at a total fatty acids concentration of 13,000 mg/l (as acetic) at pH 5, with a reactor head-gas composition of 75 percent carbon dioxide, 20 percent nitrogen, 2 percent hydrogen and 3 percent methane. Fermentation inhibition was alleviated by moving the bioleachate to a separate methane-phase fermenter, and recycling methanogenic effluents at pH 7 to the solid bed. Coupled operation of the two reactors promoted methanogenic conversion of the high-solids feed. (author)

Recent advances in industrial fermentation in Japan. [408 references

Energy Technology Data Exchange (ETDEWEB)

Yamada, K.

1977-11-01

In the field of industrial fermentation in Japan, we have made remarkable progress in this century. This rapid development may be attributed to the following factors: (a) for the past centuries the Japanese people have been familiar with handling microorganisms through the production of such traditional foods as sake (rice wine), shoyu (soya sauce), miso (soya paste), natto (fermented beans), and many other commodities. (b) The government has been always eager to promote the research and development of fermentation, establishing laboratories of applied microbiology at almost all national universities throughout the country. Researchers in this field now include large numbers of applied microbiologists including professors, researchers, and students. (c) Moreover, we are fortunate enough to have many excellent leaders in the past half century. During World War II, there was little research in Japan in the fields of aerobic fermentation, however, presently, we are playing a leading role in such fields as the production of amino acids, nucleic acids and related compounds, microbial enzymes and antibiotics, and the utilization of hydrocarbons or petrochemicals. In this article, the author wishes to offer an explanation regarding the recent advances in industrial fermentation in Japan, especially in the fields mentioned above. 408 references.

Electro-Fermentation - Merging Electrochemistry with Fermentation in Industrial Applications.

Science.gov (United States)

Schievano, Andrea; Pepé Sciarria, Tommy; Vanbroekhoven, Karolien; De Wever, Heleen; Puig, Sebastià; Andersen, Stephen J; Rabaey, Korneel; Pant, Deepak

2016-11-01

Electro-fermentation (EF) merges traditional industrial fermentation with electrochemistry. An imposed electrical field influences the fermentation environment and microbial metabolism in either a reductive or oxidative manner. The benefit of this approach is to produce target biochemicals with improved selectivity, increase carbon efficiency, limit the use of additives for redox balance or pH control, enhance microbial growth, or in some cases enhance product recovery. We discuss the principles of electrically driven fermentations and how EF can be used to steer both pure culture and microbiota-based fermentations. An overview is given on which advantages EF may bring to both existing and innovative industrial fermentation processes, and which doors might be opened in waste biomass utilization towards added-value biorefineries. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Lactic acid bacteria proteinase and quality of fermented dairy products--A review].

Science.gov (United States)

Zhang, Shuang; Zhang, Lanwei; Han, Xue

2015-12-04

Lactic acid bacteria (LAB) could synthesize cell envelope proteinase with weak activity, which primarily degrades casein. In addition to its crucial role in the rapid growth of LAB in milk, LAB proteinases are also of industrial importance due to their contribution to the formation of texture and flavor of many fermented dairy products. The proteolytic system, properties of proteinase, the degradation product of casein and its effect on the quality of fermented dairy products were reviewed in this manuscript.

Effects of dietary fibers with different fermentation characteristics on feeding motivation in adult female pigs.

Science.gov (United States)

Souza da Silva, Carol; Bolhuis, J Elizabeth; Gerrits, Walter J J; Kemp, Bas; van den Borne, Joost J G C

2013-02-17

Dietary fibers can be fermented in the colon, resulting in production of short-chain fatty acids (SCFA) and secretion of satiety-related peptides. Fermentation characteristics (fermentation kinetics and SCFA-profile) differ between fibers and could impact their satiating potential. We investigated the effects of fibers with varying fermentation characteristics on feeding motivation in adult female pigs. Sixteen pair-housed pigs received four diets in four periods in a Latin square design. Starch from a control (C) diet was exchanged, based on gross energy, for inulin (INU), guar gum (GG), or retrograded tapioca starch (RS), each at a low (L) and a high (H) inclusion level. This resulted in a decreased metabolizable energy intake when feeding fiber diets as compared with the C diet. According to in vitro fermentation measurements, INU is rapidly fermentable and yields relatively high amounts of propionate, GG is moderately rapidly fermentable and yields relatively high amounts of acetate, and RS is slowly fermentable and yields relatively high amounts of butyrate. Feeding motivation was assessed using behavioral tests at 1h, 3h and 7h after the morning meal, and home pen behavioral observations throughout the day. The number of wheel turns paid for a food reward in an operant test was unaffected by diet. Pigs on H-diets ran 25% slower for a food reward in a runway test than pigs on L-diets, and showed less spontaneous physical activity and less stereotypic behavior in the hours before the afternoon meal, reflecting increased interprandial satiety. Reduced feeding motivation with increasing inclusion level was most pronounced for RS, as pigs decreased speed in the runway test and tended to have a lower voluntary food intake in an ad libitum food intake test when fed RS-H. In conclusion, increasing levels of fermentable fibers in the diet seemed to enhance satiety in adult pigs, despite a reduction in metabolizable energy supply. RS was the most satiating fiber

Controlling alchohol fermentations

Energy Technology Data Exchange (ETDEWEB)

Leedham, P A; Tubb, R S

1983-09-21

In the initial stages of a fermentation of carbohydrate to EtOH, the growth of the yeast is controlled by monitoring the pH of a fermenting liquid or wort and controlling the supply of O/sub 2/ in accordance with the pH. The temperature of the fermenting liquid is also controlled in dependence upon the pH. The control of the fermentation process is carried out automatically by an apparatus including a fermentation vessel, a pH sensor arranged to provide an output signal representative of the pH of the liquid in the vessel, memory means to store information on the required pH with regard to the fermentation time, means to inject O/sub 2/ into the fermenting liquid and control means to compare the output signal of the pH sensor at a particular time with that of the required pH at that time, and in the event of the pH of the fermenting liquid lagging behind that required, actuate the means to inject O/sub 2/ into the fermenting liquid to increase the O/sub 2/ content of the fermenting liquid.

Dynamics in population heterogeneity during batch and continuous fermentation of Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Heins, Anna-Lena; Lencastre Fernandes, Rita; Lundin, L.

2012-01-01

Traditionally, microbial populations in optimization studies of fermentation processes have been considered homogeneous. However, research has shown that a typical microbial population in fermentation is heterogeneous. There are indications that this heterogeneity may be both beneficial...... (facilitates quick adaptation to new conditions) and harmful (reduces yields and productivities)[1,2]. Typically, gradients of e.g. dissolved oxygen, substrates, and pH are observed in industrial scale fermentation processes. Consequently, microbial cells circulating throughout a bioreactor experience rapid...... distribution during different growth stages. To further simulate which effect gradients have on population heterogeneity, glucose and ethanol perturbations during continuous cultivation were performed. Physiological changes were analyzed on single cell level by using flow cytometry followed by cell sorting...

Ethanol fermentation by immobilized cells of Zymomonas mobilis

Energy Technology Data Exchange (ETDEWEB)

Grote, W.

1985-01-01

Previous studies have shown that immobilized yeast cell cultures have commercial potential for fuel ethanol production. In this study the suitability of strains of Z. mobilis for whole cell immobilization was investigated. Experiments revealed that immobilization in Ca-alginate or K-carrageenan gel or use of flocculating strains was effective for ethanol production at relatively high productivities. Two laboratory size reactors were designed and constructed. These were a compartmented multiple discshaft column and a tower fermentor. Results of this work supported other studies that established that growth and fermentation could be uncoupled. The data indicated that specific metabolic rates were dependent on the nature of the fermentation media. The addition of lactobacilli to Z. mobilis continuous fermentations had only a transient effect, and was unlikely to affect an immobilized Z. mobilis process. With 150 gl/sup -1/ glucose media and a Z. mobilis ZM4 immobilized cell reactor, a maximum volumetric ethanol productivity of 55 gl/sup -1/h/sup -1/ was obtained. The fermentation of sucrose media or sucrose-based raw materials (molasses, cane juice, synthetic mill liquor) by immobilized Z. mobilis ZM4 revealed a pattern of rapid sucrose hydrolysis, preferential glucose utilization and the conversion of fructose to the undesirable by-products levan and sorbitol.

Characterization of fermented black soybean natto inoculated with Bacillus natto during fermentation.

Science.gov (United States)

Hu, Yongjin; Ge, Changrong; Yuan, Wei; Zhu, Renjun; Zhang, Wujiu; Du, Lijuan; Xue, Jie

2010-05-01

To make nutrients more accessible and further increase biological activity, cooked black soybeans were inoculated with Bacillus natto and fermented at 37 degrees C for 48 h. The changes in physiochemical properties of fermented black soybean natto were investigated. The inoculation procedure significantly increased moisture, viscosity, color, polyphenol compounds and anthocyanin, and significantly decreased hardness after 48 h fermentation. Fibrinolytic and caseinolytic protease, beta-glucosidase activities, TCA-soluble nitrogen, and ammonia nitrogen contents in the inoculated samples significantly increased as fermentation time increased. Genistin and daidzin concentrations gradually decreased with increased fermentation time. However, genistein and daidzein increased with fermentation time, which reached 316.8 and 305.2 microg g(-1) during 48 h fermentation, respectively. DPPH radical scavenging activities of the fermented black soybeans increased linearly with fermentation time and concentration. Compared with the soaked black soybeans and cooked black soybeans, the fermented black soybeans with B. natto resulted in higher scavenging activity towards DPPH radicals, which correlated well with the content of total phenols (r = 0.9254, P natto fermented by B. natto has the potential to become a functional food because of its high antioxidant activity.

Characterization of the Factors that Influence Sinapine Concentration in Rapeseed Meal during Fermentation

Science.gov (United States)

Niu, Yanxing; Jiang, Mulan; Guo, Mian; Wan, Chuyun; Hu, Shuangxi; Jin, Hu; Huang, Fenghong

2015-01-01

We analyzed and compared the difference in sinapine concentration in rapeseed meal between the filamentous fungus, Trametes sp 48424, and the yeast, Saccharomyces cerevisiae, in both liquid and solid-state fermentation. During liquid and solid-state fermentation by Trametes sp 48424, the sinapine concentration decreased significantly. In contrast, the liquid and solid-state fermentation process by Saccharomyces cerevisiae just slightly decreased the sinapine concentration (P ≤ 0.05). After the solid-state fermented samples were dried, the concentration of sinapine in rapeseed meal decreased significantly in Saccharomyces cerevisiae. Based on the measurement of laccase activity, we observed that laccase induced the decrease in the concentration of sinapine during fermentation with Trametes sp 48424. In order to eliminate the influence of microorganisms and the metabolites produced during fermentation, high moisture rapeseed meal and the original rapeseed meal were dried at 90°C and 105°C, respectively. During drying, the concentration of sinapine in high moisture rapeseed meal decreased rapidly and we obtained a high correlation coefficient between the concentration of sinapine and loss of moisture. Our results suggest that drying and enzymes, especially laccase that is produced during the solid-state fermentation process, may be the main factors that affect the concentration of sinapine in rapeseed meal. PMID:25606856

Comparison of protein fermentation characteristics in rumen fluid determined with the gas production technique and the nylon bag technique

NARCIS (Netherlands)

Cone, J.W.; Rodrigues, M.A.M.; Guedes, C.M.; Blok, M.C.

2009-01-01

In this study, a modified version of the gas production technique was used to determine protein fermentation characteristics in rumen fluid of 19 feedstuffs. Performing the incubations in a N-free environment, and with an excess of rapidly fermentable carbohydrates, made N the limiting factor to

Treatment and processing of residues of fermentation; Behandlung und Verwertung von Gaerrueckstaenden

Energy Technology Data Exchange (ETDEWEB)

Doehler, H.; Schliebner, P. [Kuratorium fuer Technik und Bauwesen in der Landwirtschaft (KTBL), Darmstadt (Germany)

2007-07-01

With the transformation of the EEG (Renewable Energy Resources Act), the number of biogas plants increased rapidly. Additionally, an enlargement of the performance of the plants and a regional concentration process take place. Recently, processing routes for liquid manure will be considered in order to reduce problems of the surplus of nutrients as well as the costs of the transport of the water-rich residues of fermentation. Under this aspect, the authors of the contribution under consideration report on procedures for the processing of residues of fermentation as well as costs and utilization of these procedures. By the example of an agrarian society, four procedures for the output and processing of residues of fermentation are compared with one another regarding to expenditure of work time, investments and economy: Output of residues of fermentation, treatment of residues of fermentation by separation, processing of residues of fermentation by means of diaphragm technology, processing of residues of fermentation by means of evaporation technology. The processing routes reduce the residues of fermentation by 60 %. Thus, the costs of output and the necessary storage capacities for residues of fermentation are reduced. Presently, no savings regarding to work completion by the processing of the residues of fermentation can be obtained. The specific total costs of the investigated procedures are between 2.64 Euro/m{sup 3} according to the procedure with separation and to 8.64 Euro/m{sup 3} according to the diaphragm processing route. An enhanced demand of investment does not cause compellingly the highest specific total costs of the procedures. In comparison to the output of residues of fermentation, the examined procedures for the processing of residues of fermentation do not result in economical and ergonomic advantages. The high costs of investment and operating cost of the processing of residues of fermentation cannot be compensated by the reduced costs of output

Controlled fermentation of Moroccan picholine green olives by oleuropein-degrading Lactobacilli strains

Energy Technology Data Exchange (ETDEWEB)

Ghabbour, N.; Rokni, Y.; Lamzira, Z.; Thonart, P.; Chihib, N.E.; Peres, C.; Asehraou, A.

2016-07-01

The control of the spontaneous fermentation process of un-debittered Moroccan Picholine green olives was undertaken basing the inoculation with two lactobacilli strains (Lactobacillus plantarum S175 and Lactobacillus pentosus S100). These strains, previously selected in our laboratory for their oleuropein-degrading capacity, were inoculated in olives brined at 5% of NaCl, and then incubated at 30 °C. The physico-chemical parameters (pH, free acidity, reducing sugars, sodium chloride, oleuropein and its hydrolysis products), and the microbiological parameters (mesophilic aerobic bacteria, coliforms, Staphylococcus, lactic acid bacteria and yeasts and moulds), were regularly analyzed during the fermentation time. The results obtained showed the effectiveness of the lactic acid bacteria strains to develop suitable oleuropein biodegradation and controlled lactic fermentation processes more than the un-inoculated olives (control). This result was confirmed by the rapid elimination of coliforms and staphylococcus, the accumulation of hydroxytyrosol as a result of oleuropein biodegradation, and a drastic reduction in spoiled olives with good quality fermented olives. (Author)

Coevolution with bacteria drives the evolution of aerobic fermentation in Lachancea kluyveri.

Directory of Open Access Journals (Sweden)

Nerve Zhou

Full Text Available The Crabtree positive yeasts, such as Saccharomyces cerevisiae, prefer fermentation to respiration, even under fully aerobic conditions. The selective pressures that drove the evolution of this trait remain controversial because of the low ATP yield of fermentation compared to respiration. Here we propagate experimental populations of the weak-Crabtree yeast Lachancea kluyveri, in competitive co-culture with bacteria. We find that L. kluyveri adapts by producing quantities of ethanol lethal to bacteria and evolves several of the defining characteristics of Crabtree positive yeasts. We use precise quantitative analysis to show that the rate advantage of fermentation over aerobic respiration is insufficient to provide an overall growth advantage. Thus, the rapid consumption of glucose and the utilization of ethanol are essential for the success of the aerobic fermentation strategy. These results corroborate that selection derived from competition with bacteria could have provided the impetus for the evolution of the Crabtree positive trait.

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

Directory of Open Access Journals (Sweden)

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.

A strain of Saccharomyces cerevisiae evolved for fermentation of lignocellulosic biomass displays improved growth and fermentative ability in high solids concentrations and in the presence of inhibitory compounds

Directory of Open Access Journals (Sweden)

Hawkins Gary M

2011-11-01

Full Text Available Abstract Background Softwoods are the dominant source of lignocellulosic biomass in the northern hemisphere, and have been investigated worldwide as a renewable substrate for cellulosic ethanol production. One challenge to using softwoods, which is particularly acute with pine, is that the pretreatment process produces inhibitory compounds detrimental to the growth and metabolic activity of fermenting organisms. To overcome the challenge of bioconversion in the presence of inhibitory compounds, especially at high solids loading, a strain of Saccharomyces cerevisiae was subjected to evolutionary engineering and adaptation for fermentation of pretreated pine wood (Pinus taeda. Results An industrial strain of Saccharomyces, XR122N, was evolved using pretreated pine; the resulting daughter strain, AJP50, produced ethanol much more rapidly than its parent in fermentations of pretreated pine. Adaptation, by preculturing of the industrial yeast XR122N and the evolved strains in 7% dry weight per volume (w/v pretreated pine solids prior to inoculation into higher solids concentrations, improved fermentation performance of all strains compared with direct inoculation into high solids. Growth comparisons between XR122N and AJP50 in model hydrolysate media containing inhibitory compounds found in pretreated biomass showed that AJP50 exited lag phase faster under all conditions tested. This was due, in part, to the ability of AJP50 to rapidly convert furfural and hydroxymethylfurfural to their less toxic alcohol derivatives, and to recover from reactive oxygen species damage more quickly than XR122N. Under industrially relevant conditions of 17.5% w/v pretreated pine solids loading, additional evolutionary engineering was required to decrease the pronounced lag phase. Using a combination of adaptation by inoculation first into a solids loading of 7% w/v for 24 hours, followed by a 10% v/v inoculum (approximately equivalent to 1 g/L dry cell weight into 17

D-tagatose, a novel hexose: acute effects on carbohydrate tolerance in subjects with and without type 2 diabetes.

Science.gov (United States)

Donner, T W; Wilber, J F; Ostrowski, D

1999-09-01

D-Tagatose (D-tag), a hexose bulk sweetener, does not affect plasma glucose levels when orally administered to rodents. Additionally, D-tag attenuates the rise in plasma glucose after mice are administered oral sucrose. The current study was undertaken to investigate the acute glycaemic effects of oral D-tag alone or in combination with oral glucose in human subjects with and without type 2 diabetes mellitus. Glycaemic responses to D-tag also were investigated in subjects after oral sucrose to examine whether the glucose-lowering effects of D-tag in rodents may result from a direct inhibition of intestinal disaccharidases. Eight normal and eight subjects with diabetes mellitus were administered 75 g of glucose, 75 g of D-tag, or 75 g of D-tag 30 min prior to a 75 g oral glucose tolerance test (OGTT). Five patients with diabetes mellitus were challenged with a 75 g oral sucrose tolerance test (OSTT) with and without oral pre-treatment with 75 g of D-tag. Patients with diabetes mellitus also received separate 0, 10, 15, 20 and 30 g of D-tag 30 min prior to a 75 g OGTT. Oral loading with D-tag alone led to no changes in glucose or insulin levels in either normal patients or those with diabetes mellitus. Pre-OGTT treatment with 75 g D-tag, however, attenuated the rise in glucose levels in patients with diabetes mellitus (p effects seen following larger doses of D-tag support poor absorption of this hexose and suggest that D-tag may act by attenuating glucose absorption in the intestine. D-tag may be a useful therapeutic adjunct in the management of type 2 diabetes mellitus.

Acetone-butanol fermentation of blackstrap molasses. An effective factor of some symbiotic organisms against an abnormal fermentation. [Torula utilis

Energy Technology Data Exchange (ETDEWEB)

Shige, A; Kinoshita, S; Okumura, T

1954-01-01

There were three types of industrial acetone-butanol fermentation of blackstrap molasses; one of them, called B type, was characterized by the extremely prolonged acidity peak, and sluggishness experiments were carried out to find some symbiotic organisms among various aerobic bacteria and yeasts for several strains of Clostridium acetobutylicum. Torula utilis showed an outstanding effectiveness for a rapid completion of the fermentation, and the yields of solvents was much increased. Culture filtrate of T. utilis contained a soluble and invertase activity. A close relation was found between high yields of solvents and the degree of inversion of molasses medium. Thus, the effective factor against sluggishness was ascribed to the invertase activity of the yeast. Some inhibiting factors to invertase of C. acetobutylicum were presumed to be present in molasses as the principal cause of the sluggishness.

Rapid purification and plasticization of D-glutamate-containing poly-γ-glutamate from Japanese fermented soybean food natto.

Science.gov (United States)

Ashiuchi, Makoto; Oike, Shota; Hakuba, Hirofumi; Shibatani, Shigeo; Oka, Nogiho; Wakamatsu, Taisuke

2015-12-10

Poly-γ-glutamate (PGA) is a major component of mucilage derived from natto, a Japanese fermented food made from soybeans, and PGAs obtained under laboratory's conditions contain numerous d-glutamyl residues. Natto foods are thus promising as a source for nutritionally safe d-amino acids present in intact and digested polymers, although there is little information on the stereochemistry of PGA isolated directly from natto. Here, we describe the development of a new process for rapid purification of PGA using alum and determined the D-glutamate content of natto PGA by chiral high-performance liquid chromatographic analysis. Further, using hexadecylpyridinium cation (HDP(+)), which is a compound of toothpaste, we chemically transformed natto PGA into a new thermoplastic material, called DL-PGAIC. (1)H nuclear magnetic resonance and calorimetric measurements indicate that DL-PGAIC is a stoichiometric complex of natto PGA and HDP(+) with glass transition points of -16.8 °C and -3.1 °C. Then, DL-PGAIC began decomposing at 210°C, suggesting thermal stability suitable for use as a supramolecular soft plastic. Copyright © 2015 Elsevier B.V. All rights reserved.

Quantitation & Case-Study-Driven Inquiry to Enhance Yeast Fermentation Studies

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Grammer, Robert T.

2012-01-01

We propose a procedure for the assay of fermentation in yeast in microcentrifuge tubes that is simple and rapid, permitting assay replicates, descriptive statistics, and the preparation of line graphs that indicate reproducibility. Using regression and simple derivatives to determine initial velocities, we suggest methods to compare the effects of…

Residual mitochondrial transmembrane potential decreases unsaturated fatty acid level in sake yeast during alcoholic fermentation

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Kazutaka Sawada

2016-01-01

Full Text Available Oxygen, a key nutrient in alcoholic fermentation, is rapidly depleted during this process. Several pathways of oxygen utilization have been reported in the yeast Saccharomyces cerevisiae during alcoholic fermentation, namely synthesis of unsaturated fatty acid, sterols and heme, and the mitochondrial electron transport chain. However, the interaction between these pathways has not been investigated. In this study, we showed that the major proportion of unsaturated fatty acids of ester-linked lipids in sake fermentation mash is derived from the sake yeast rather than from rice or koji (rice fermented with Aspergillus. Additionally, during alcoholic fermentation, inhibition of the residual mitochondrial activity of sake yeast increases the levels of unsaturated fatty acids of ester-linked lipids. These findings indicate that the residual activity of the mitochondrial electron transport chain reduces molecular oxygen levels and decreases the synthesis of unsaturated fatty acids, thereby increasing the synthesis of estery flavors by sake yeast. This is the first report of a novel link between residual mitochondrial transmembrane potential and the synthesis of unsaturated fatty acids by the brewery yeast during alcoholic fermentation.

Influence of pre-fermentation cold maceration treatment on aroma compounds of Cabernet Sauvignon wines fermented in different industrial scale fermenters.

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Cai, Jian; Zhu, Bao-Qing; Wang, Yun-He; Lu, Lin; Lan, Yi-Bin; Reeves, Malcolm J; Duan, Chang-Qing

2014-07-01

The influence of pre-fermentation cold maceration (CM) on Cabernet Sauvignon wines fermented in two different industrial-scale fermenters was studied. CM treatment had different effects on wine aroma depending on the types of fermenter, being more effective for automatic pumping-over tank (PO-tank) than automatic punching-down tank (PD-tank). When PO-tank was used, CM-treated wine showed a decrease in some fusel alcohols (isobutanol and isopentanol) and an increase in some esters (especially acetate esters). However, no significant changes were detected in these compounds when PD-tank was used. Ethyl 2-hexenoate and diethyl succinate were decreased, while geranylacetone was increased by the CM treatment in both fermenters. β-Damascenone was increased by the CM treatment in PO-tank fermented wines but decreased in PD-tank fermented wines. The fruity, caramel and floral aroma series were enhanced while chemical series were decreased by the CM treatment in PO-tank fermented wines. The content of (Z)-6-nonen-1-ol in the final wines was positively correlated to CM treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

GUT FERMENTATION SYNDROME

African Journals Online (AJOL)

boaz

individuals who became intoxicated after consuming carbohydrates, which became fermented in the gastrointestinal tract. These claims of intoxication without drinking alcohol, and the findings on endogenous alcohol fermentation are now called Gut. Fermentation Syndrome. This review will concentrate on understanding ...

High cell density fed-batch fermentations for lipase production: feeding strategies and oxygen transfer.

Science.gov (United States)

Salehmin, M N I; Annuar, M S M; Chisti, Y

2013-11-01

This review is focused on the production of microbial lipases by high cell density fermentation. Lipases are among the most widely used of the enzyme catalysts. Although lipases are produced by animals and plants, industrial lipases are sourced almost exclusively from microorganisms. Many of the commercial lipases are produced using recombinant species. Microbial lipases are mostly produced by batch and fed-batch fermentation. Lipases are generally secreted by the cell into the extracellular environment. Thus, a crude preparation of lipases can be obtained by removing the microbial cells from the fermentation broth. This crude cell-free broth may be further concentrated and used as is, or lipases may be purified from it to various levels. For many large volume applications, lipases must be produced at extremely low cost. High cell density fermentation is a promising method for low-cost production: it allows a high concentration of the biomass and the enzyme to be attained rapidly and this eases the downstream recovery of the enzyme. High density fermentation enhances enzyme productivity compared with the traditional submerged culture batch fermentation. In production of enzymes, a high cell density is generally achieved through fed-batch operation, not through perfusion culture which is cumbersome. The feeding strategies used in fed-batch fermentations for producing lipases and the implications of these strategies are discussed. Most lipase-producing microbial fermentations require oxygen. Oxygen transfer in such fermentations is discussed.

Reduction of verotoxigenic Escherichia coli in production of fermented sausages.

Science.gov (United States)

Holck, Askild L; Axelsson, Lars; Rode, Tone Mari; Høy, Martin; Måge, Ingrid; Alvseike, Ole; L'abée-Lund, Trine M; Omer, Mohamed K; Granum, Per Einar; Heir, Even

2011-11-01

After a number of foodborne outbreaks of verotoxigenic Escherichia coli involving fermented sausages, some countries have imposed regulations on sausage production. For example, the US Food Safety and Inspection Service requires a 5 log(10) reduction of E. coli in fermented products. Such regulations have led to a number of studies on the inactivation of E. coli in fermented sausages by changing processing and post-processing conditions. Several factors influence the survival of E. coli such as pre-treatment of the meat, amount of NaCl, nitrite and lactic acid, water activity, pH, choice of starter cultures and addition of antimicrobial compounds. Also process variables like fermentation temperature and storage time play important roles. Though a large variety of different production processes of sausages exist, generally the reduction of E. coli caused by production is in the range 1-2 log(10). In many cases this may not be enough to ensure microbial food safety. By optimising ingredients and process parameters it is possible to increase E. coli reduction to some extent, but in some cases still other post process treatments may be required. Such treatments may be storage at ambient temperatures, specific heat treatments, high pressure processing or irradiation. HACCP analyses have identified the quality of the raw materials, low temperature in the batter when preparing the sausages and a rapid pH drop during fermentation as critical control points in sausage production. This review summarises the literature on the reduction verotoxigenic E. coli in production of fermented sausages. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparative genomics of xylose-fermenting fungi for enhanced biofuel production

Energy Technology Data Exchange (ETDEWEB)

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

2011-02-24

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 capacity pales in comparison with glucose, limiting the economic feasibility of industrial fermentations. To better understand xylose utilization for subsequent microbial engineering, we sequenced the genomes of two xylose-fermenting, beetle-associated fungi, Spathaspora passalidarum and Candida tenuis. To identify genes involved in xylose metabolism, we applied a comparative genomic approach across 14 Ascomycete genomes, mapping phenotypes and genotypes onto the fungal phylogeny, and measured genomic expression across five Hemiascomycete species with different xylose-consumption phenotypes. This approach implicated many genes and processes involved in xylose assimilation. Several of these genes significantly improved xylose utilization when engineered into S. cerevisiae, demonstrating the power of comparative methods in rapidly identifying genes for biomass conversion while reflecting on fungal ecology.

effective extraction of cephalosporin c from whole fermentation broth

African Journals Online (AJOL)

amina

2012-04-17

Apr 17, 2012 ... The effects of pH, neutral salts, temperature and centrifugal force on .... Fermentation was carried out in a defined media developed with slight modifications ... were pH 6.5, 200 rpm and incubation of culture for 72 h, as determined in our ... that CPC is rapidly inactivated at pH 12, while it is stable at pH 3.5.

Quality and Composition of Red Wine Fermented with Schizosaccharomyces pombe as Sole Fermentative Yeast, and in Mixed and Sequential Fermentations with Saccharomyces cerevisiae

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Felipe Palomero

2014-01-01

Full Text Available This work examines the physiology of Schizosaccharomyces pombe (represented by strain 938 in the production of red wine, as the sole fermentative yeast, and in mixed and sequential fermentations with Saccharomyces cerevisiae 796. For further comparison, fermentations in which Saccharomyces cerevisiae was the sole fermentative yeast were also performed; in these fermentations a commercial lactic acid bacterium was used to perform malolactic fermentation once alcoholic fermentation was complete (unlike S. cerevisiae, the Sc. pombe performs maloalcoholic fermentation and therefore removes malic acid without such help. Relative density, acetic, malic and pyruvic acid concentrations, primary amino nitrogen and urea concentrations, and pH of the musts were measured over the entire fermentation period. In all fermentations in which Sc. pombe 938 was involved, nearly all the malic acid was consumed from an initial concentration of 5.5 g/L, and moderate acetic acid concentrations below 0.4 g/L were formed. The urea content of these wines was notably lower, showing a tenfold reduction when compared with those that were made with S. cerevisiae 796 alone. The sensorial properties of the different final wines varied widely. The wines fermented with Sc. pombe 938 had maximum aroma intensity and quality, and they were preferred by the tasters.

Protein concentrations of sweet soysauces from Rhizopus oryzae and R. oligosporus fermentation without moromi fermentation

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NOOR SOESANTI HANDAJANI

2007-07-01

Full Text Available Soy sauce was produce from soybean that fermented with koji/tempeh fungi and thenfermented under salt solution or moromi fermentation. The objectives of this experiment was to compare of protein (total and soluble content of sweet soy sauce that produced from soybean fermented with Rhizopus oryzae and R. oligosporus without moromi fermentation to the sweet soysauce with moromi fermentation one. The total and soluble proteins of sweet soy sauces that produce from soybean without moromi fermentation were higher that sweet soy sauces that produce with moromi fermentation. Soluble protein of sweet soy sauce that produced from soybean fermented with R. oligosporus without moromi fermentation was 8.2% and meet to the highest quality of sweet soy sweet sauce based on Indonesia Industrial Standard. Soluble protein of sweet soy sauce that produced from soybean fermented with R. oryzae without moromi fermentation was 4.1% and meet to the medium quality of sweet soy sweet sauce based on Indonesia Industrial Standard.

Fermentable sugar in ammonium and calcium bisulfite pulping and ethanol production therefrom

Energy Technology Data Exchange (ETDEWEB)

Samuelson, O; Schoon, N H; Ingvar, E

1955-01-01

The yields of fermentable sugar and EtOH were determined on spruce chips pulped with NH/sub 4/HSO/sub 3/ and Ca(HSO/sub 3/)/sub 2/. The yield of fermentable sugar is plotted vs the yield of pulp; the curve shows a difference in sugar content for the two bases during the first part of the process. With yields of pulp below 44%, this difference disappears. Univalent ions (other than NH/sub 4//sup +/) have a beneficial effect on the sugar yield. Consequently, the destruction of the sugar is more rapid when NH/sub 4//sup +/ is used.

Efficient hydrogen production from the lignocellulosic energy crop Miscanthus by the extreme thermophilic bacteria Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana

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de Vrije Truus

2009-06-01

Full Text Available Abstract Background The production of hydrogen from biomass by fermentation is one of the routes that can contribute to a future sustainable hydrogen economy. Lignocellulosic biomass is an attractive feedstock because of its abundance, low production costs and high polysaccharide content. Results Batch cultures of Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana produced hydrogen, carbon dioxide and acetic acid as the main products from soluble saccharides in Miscanthus hydrolysate. The presence of fermentation inhibitors, such as furfural and 5-hydroxylmethyl furfural, in this lignocellulosic hydrolysate was avoided by the mild alkaline-pretreatment conditions at a low temperature of 75°C. Both microorganisms simultaneously and completely utilized all pentoses, hexoses and oligomeric saccharides up to a total concentration of 17 g l-1 in pH-controlled batch cultures. T. neapolitana showed a preference for glucose over xylose, which are the main sugars in the hydrolysate. Hydrogen yields of 2.9 to 3.4 mol H2 per mol of hexose, corresponding to 74 to 85% of the theoretical yield, were obtained in these batch fermentations. The yields were higher with cultures of C. saccharolyticus compared to T. neapolitana. In contrast, the rate of substrate consumption and hydrogen production was higher with T. neapolitana. At substrate concentrations exceeding 30 g l-1, sugar consumption was incomplete, and lower hydrogen yields of 2.0 to 2.4 mol per mol of consumed hexose were obtained. Conclusion Efficient hydrogen production in combination with simultaneous and complete utilization of all saccharides has been obtained during the growth of thermophilic bacteria on hydrolysate of the lignocellulosic feedstock Miscanthus. The use of thermophilic bacteria will therefore significantly contribute to the energy efficiency of a bioprocess for hydrogen production from biomass.

Monitoring of beer fermentation based on hybrid electronic tongue.

Science.gov (United States)

Kutyła-Olesiuk, Anna; Zaborowski, Michał; Prokaryn, Piotr; Ciosek, Patrycja

2012-10-01

Monitoring of biotechnological processes, including fermentation is extremely important because of the rapidly occurring changes in the composition of the samples during the production. In the case of beer, the analysis of physicochemical parameters allows for the determination of the stage of fermentation process and the control of its possible perturbations. As a tool to control the beer production process a sensor array can be used, composed of potentiometric and voltammetric sensors (so-called hybrid Electronic Tongue, h-ET). The aim of this study is to apply electronic tongue system to distinguish samples obtained during alcoholic fermentation. The samples originate from batch of homemade beer fermentation and from two stages of the process: fermentation reaction and maturation of beer. The applied sensor array consists of 10 miniaturized ion-selective electrodes (potentiometric ET) and silicon based 3-electrode voltammetric transducers (voltammetric ET). The obtained results were processed using Partial Least Squares (PLS) and Partial Least Squares-Discriminant Analysis (PLS-DA). For potentiometric data, voltammetric data, and combined potentiometric and voltammetric data, comparison of the classification ability was conducted based on Root Mean Squared Error (RMSE), sensitivity, specificity, and coefficient F calculation. It is shown, that in the contrast to the separately used techniques, the developed hybrid system allowed for a better characterization of the beer samples. Data fusion in hybrid ET enables to obtain better results both in qualitative analysis (RMSE, specificity, sensitivity) and in quantitative analysis (RMSE, R(2), a, b). Copyright © 2012 Elsevier B.V. All rights reserved.

Solid substrate fermentation

Energy Technology Data Exchange (ETDEWEB)

Tengerdy, R P

1985-04-01

Solid Substrate Fermentation (SSF) describes the microbiological tranformation of biological materials in their natural state, in contrast with liquid or submerged fermentations which are carried out in dilute solutions or slurries. The most important industrial microorganisms used in SSF are filamentous fungi and the critical factors in their growth are the control of the moisture level and the temperature. Traditionally, most SSFs are conducted in shallow trays (so that heat build up is avoided) and stacked in a moist chamber, however, the modern SSF should be able to mix large amounts of substrate for a uniform fermentation, maximum automization scale-up of the process, continuous operation and fermentation control and a promising new design is the Helical screw fermenter. At the present time SSF is used in the production of foods (e.g. mushrooms and oriental foods) in municipal, agricultural and industrial solid waste disposal and in the production of enzymes and speciality chemicals but it does not seem likely that it will replace prevalent liquid fermentation technologies. 29 references.

Defective quiescence entry promotes the fermentation performance of bottom-fermenting brewer's yeast.

Science.gov (United States)

Oomuro, Mayu; Kato, Taku; Zhou, Yan; Watanabe, Daisuke; Motoyama, Yasuo; Yamagishi, Hiromi; Akao, Takeshi; Aizawa, Masayuki

2016-11-01

One of the key processes in making beer is fermentation. In the fermentation process, brewer's yeast plays an essential role in both the production of ethanol and the flavor profile of beer. Therefore, the mechanism of ethanol fermentation by of brewer's yeast is attracting much attention. The high ethanol productivity of sake yeast has provided a good basis from which to investigate the factors that regulate the fermentation rates of brewer's yeast. Recent studies found that the elevated fermentation rate of sake Saccharomyces cerevisiae species is closely related to a defective transition from vegetative growth to the quiescent (G 0 ) state. In the present study, to clarify the relationship between the fermentation rate of brewer's yeast and entry into G 0 , we constructed two types of mutant of the bottom-fermenting brewer's yeast Saccharomyces pastorianus Weihenstephan 34/70: a RIM15 gene disruptant that was defective in entry into G 0 ; and a CLN3ΔPEST mutant, in which the G 1 cyclin Cln3p accumulated at high levels. Both strains exhibited higher fermentation rates under high-maltose medium or high-gravity wort conditions (20° Plato) as compared with the wild-type strain. Furthermore, G 1 arrest and/or G 0 entry were defective in both the RIM15 disruptant and the CLN3ΔPEST mutant as compared with the wild-type strain. Taken together, these results indicate that regulation of the G 0 /G 1 transition might govern the fermentation rate of bottom-fermenting brewer's yeast in high-gravity wort. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Comparing the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways in arabinose and xylose fermenting Saccharomyces cerevisiae strains

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Hahn-Hägerdal Bärbel

2008-10-01

Full Text Available Abstract Background Ethanolic fermentation of lignocellulosic biomass is a sustainable option for the production of bioethanol. This process would greatly benefit from recombinant Saccharomyces cerevisiae strains also able to ferment, besides the hexose sugar fraction, the pentose sugars, arabinose and xylose. Different pathways can be introduced in S. cerevisiae to provide arabinose and xylose utilisation. In this study, the bacterial arabinose isomerase pathway was combined with two different xylose utilisation pathways: the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways, respectively, in genetically identical strains. The strains were compared with respect to aerobic growth in arabinose and xylose batch culture and in anaerobic batch fermentation of a mixture of glucose, arabinose and xylose. Results The specific aerobic arabinose growth rate was identical, 0.03 h-1, for the xylose reductase/xylitol dehydrogenase and xylose isomerase strain. The xylose reductase/xylitol dehydrogenase strain displayed higher aerobic growth rate on xylose, 0.14 h-1, and higher specific xylose consumption rate in anaerobic batch fermentation, 0.09 g (g cells-1 h-1 than the xylose isomerase strain, which only reached 0.03 h-1 and 0.02 g (g cells-1h-1, respectively. Whereas the xylose reductase/xylitol dehydrogenase strain produced higher ethanol yield on total sugars, 0.23 g g-1 compared with 0.18 g g-1 for the xylose isomerase strain, the xylose isomerase strain achieved higher ethanol yield on consumed sugars, 0.41 g g-1 compared with 0.32 g g-1 for the xylose reductase/xylitol dehydrogenase strain. Anaerobic fermentation of a mixture of glucose, arabinose and xylose resulted in higher final ethanol concentration, 14.7 g l-1 for the xylose reductase/xylitol dehydrogenase strain compared with 11.8 g l-1 for the xylose isomerase strain, and in higher specific ethanol productivity, 0.024 g (g cells-1 h-1 compared with 0.01 g (g cells-1 h-1

Exploring microbial succession and diversity during solid-state fermentation of Tianjin duliu mature vinegar.

Science.gov (United States)

Nie, Zhiqiang; Zheng, Yu; Wang, Min; Han, Yue; Wang, Yuenan; Luo, Jianmei; Niu, Dandan

2013-11-01

Tianjin duliu mature vinegar was one of famous Chinese traditional vinegars. The unique flavor and taste of vinegar are mainly generated by the multitudinous microorganisms during fermentation. In this research, the composition and succession of microbial communities in the entire solid-state fermentation were investigated, including starter daqu and acetic acid fermentation (AAF). Molds and yeasts in daqu, including Aspergillus, Saccharomycopsis and Pichia, decreased in AAF. The bacterial compositions increased from four genera in daqu to more than 13 genera in AAF. Principal component analysis showed that Acetobacter, Gluconacetobacter, Lactobacillus and Nostoc were dominant bacteria that were correlated well with AAF process. In the early fermentation period, lactic acid bacteria (LAB) decreased while acetic acid bacteria and Nostoc increased rapidly with the accumulation of total acids. Then, the abundance and diversity of LAB increased (more than 80%), indicating that LAB had important influences on the flavor and taste of vinegar. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enzymes in Fermented Fish.

Science.gov (United States)

Giyatmi; Irianto, H E

Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

Probiotic fermented dairy products

OpenAIRE

Adnan Tamime; Rajka Božanić; Irena Rogelj

2003-01-01

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

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.

EFFECT OF FERMENTED CACAO POD SUPPLEMENTATION ON SHEEP RUMEN MICROBIAL FERMENTATION

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S. Wulandari

2015-09-01

Full Text Available The objective of this research was to improve beneficial value of cacao pod as sheep feedingredients comprising up to 50% total feed. This research was conducted in two stages. Stage 1 wascacao pod fermentation. Completely randomized design with 3x3 factorial patterns was used in thisstage, in which factor I was microbial inoculum dosage of 0%, 0.05% and 0.1% and factor II wasincubation period of 0, 3 and 6 days. Result demonstrated that six-day fermentation with 0.05%microbial inoculum could lower cacao NDF, ADF and theobromine. The optimum inoculum dosage andfermentation time from stage 1 was applied to stage 2. Stage 2 was rumen microbial fermentation test.This research administrated 3x3 of latin square design. In period I sheep were fed with CF0 (nonfermentedcomplete feed, in period II sheep were given CF 1 (complete feed containing fermentedcacao pod and in period III sheep were given CF2 (fermented complete feed based cacao pod. Resultdemonstrated that pH value of sheep microbial liquid in treatment of CF0, CF1 and CF2 was in normalpH range and did not affect volatile fatty acids (VFA and ammonia. In conclusion, supplementing up to 50% of feed with complete feed containing fermented or non-fermented cacao pod did not affect theprocess of rumen microbial fermentation.

Fermentation performance optimization in an ectopic fermentation system.

Science.gov (United States)

Yang, Xiaotong; Geng, Bing; Zhu, Changxiong; Li, Hongna; He, Buwei; Guo, Hui

2018-07-01

Ectopic fermentation systems (EFSs) were developed for wastewater treatment. Previous studies have investigated the ability of thermophilic bacteria to improve fermentation performance in EFS. Continuing this research, we evaluated EFS performance using principle component analysis and investigated the addition of different proportions of cow dung. Viable bacteria communities were clustered and identified using BOX-AIR-based repetitive extragenic palindromic-PCR and 16S rDNA analysis. The results revealed optimal conditions for the padding were maize straw inoculated with thermophilic bacteria. Adding 20% cow dung yielded the best pH values (6.94-8.56), higher temperatures, increased wastewater absorption, improved litter quality, and greater microbial quantities. The viable bacteria groups were enriched by the addition of thermophilic consortium, and exogenous strains G21, G14, G4-1, and CR-15 were detected in fermentation process. The proportion of Bacillus species in treatment groups reached 70.37% after fermentation, demonstrating that thermophilic bacteria, especially Bacillus, have an important role in EFS, supporting previous predictions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electro-Fermentation in Aid of Bioenergy and Biopolymers

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Prasun Kumar

2018-02-01

Full Text Available The soaring levels of industrialization and rapid progress towards urbanization across the world have elevated the demand for energy besides generating a massive amount of waste. The latter is responsible for poisoning the ecosystem in an exponential manner, owing to the hazardous and toxic chemicals released by them. In the past few decades, there has been a paradigm shift from “waste to wealth”, keeping the value of high organic content available in the wastes of biological origin. The most practiced processes are that of anaerobic digestion, leading to the production of methane. However; such bioconversion has limited net energy yields. Industrial fermentation targeting value-added bioproducts such as—H2, butanediols; polyhydroxyalkanoates, citric acid, vitamins, enzymes, etc. from biowastes/lignocellulosic substrates have been planned to flourish in a multi-step process or as a “Biorefinery”. Electro-fermentation (EF is one such technology that has attracted much interest due to its ability to boost the microbial metabolism through extracellular electron transfer during fermentation. It has been studied on various acetogens and methanogens, where the enhancement in the biogas yield reached up to 2-fold. EF holds the potential to be used with complex organic materials, leading to the biosynthesis of value-added products at an industrial scale.

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.

Recent advances in electronic nose techniques for monitoring of fermentation process.

Science.gov (United States)

Jiang, Hui; Zhang, Hang; Chen, Quansheng; Mei, Congli; Liu, Guohai

2015-12-01

Microbial fermentation process is often sensitive to even slight changes of conditions that may result in unacceptable end-product quality. Thus, the monitoring of the process is critical for discovering unfavorable deviations as early as possible and taking the appropriate measures. However, the use of traditional analytical techniques is often time-consuming and labor-intensive. In this sense, the most effective way of developing rapid, accurate and relatively economical method for quality assurance in microbial fermentation process is the use of novel chemical sensor systems. Electronic nose techniques have particular advantages in non-invasive monitoring of microbial fermentation process. Therefore, in this review, we present an overview of the most important contributions dealing with the quality control in microbial fermentation process using the electronic nose techniques. After a brief description of the fundamentals of the sensor techniques, some examples of potential applications of electronic nose techniques monitoring are provided, including the implementation of control strategies and the combination with other monitoring tools (i.e. sensor fusion). Finally, on the basis of the review, the electronic nose techniques are critically commented, and its strengths and weaknesses being highlighted. In addition, on the basis of the observed trends, we also propose the technical challenges and future outlook for the electronic nose techniques.

A simple Pichia pastoris fermentation and downstream processing strategy for making recombinant pandemic Swine Origin Influenza a virus Hemagglutinin protein.

Science.gov (United States)

Athmaram, T N; Singh, Anil Kumar; Saraswat, Shweta; Srivastava, Saurabh; Misra, Princi; Kameswara Rao, M; Gopalan, N; Rao, P V L

2013-02-01

The present Influenza vaccine manufacturing process has posed a clear impediment to initiation of rapid mass vaccination against spreading pandemic influenza. New vaccine strategies are therefore needed that can accelerate the vaccine production. Pichia offers several advantages for rapid and economical bulk production of recombinant proteins and, hence, can be attractive alternative for producing an effective influenza HA based subunit vaccine. The recombinant Pichia harboring the transgene was subjected to fed-batch fermentation at 10 L scale. A simple fermentation and downstream processing strategy is developed for high-yield secretory expression of the recombinant Hemagglutinin protein of pandemic Swine Origin Influenza A virus using Pichia pastoris via fed-batch fermentation. Expression and purification were optimized and the expressed recombinant Hemagglutinin protein was verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blot and MALDI-TOF analysis. In this paper, we describe a fed-batch fermentation protocol for the secreted production of Swine Influenza A Hemagglutinin protein in the P. pastoris GS115 strain. We have shown that there is a clear relationship between product yield and specific growth rate. The fed-batch fermentation and downstream processing methods optimized in the present study have immense practical application for high-level production of the recombinant H1N1 HA protein in a cost effective way using P. pastoris.

Relationship between fermentation index and other biochemical changes evaluated during the fermentation of Mexican cocoa (Theobroma cacao) beans.

Science.gov (United States)

Romero-Cortes, Teresa; Salgado-Cervantes, Marco Antonio; García-Alamilla, Pedro; García-Alvarado, Miguel Angel; Rodríguez-Jimenes, Guadalupe del C; Hidalgo-Morales, Madeleine; Robles-Olvera, Víctor

2013-08-15

During traditional cocoa processing, the end of fermentation is empirically determined by the workers; consequently, a high variability on the quality of fermented cocoa beans is observed. Some physicochemical properties (such as fermentation index) have been used to measure the degree of fermentation and changes in quality, but only after the fermentation process has concluded, using dried cocoa beans. This would suggest that it is necessary to establish a relationship between the chemical changes inside the cocoa bean and the fermentation conditions during the fermentation in order to standardize the process. Cocoa beans were traditionally fermented inside wooden boxes, sampled every 24 h and analyzed to evaluate fermentation changes in complete bean, cotyledon and dried beans. The value of the fermentation index suggested as the minimal adequate (≥1) was observed at 72 h in all bean parts analyzed. At this time, values of pH, spectral absorption, total protein hydrolysis and vicilin-class globulins of fermented beans suggested that they were well fermented. Since no difference was found between the types of samples, the pH value could be used as a first indicator of the end of the fermentation and confirmed by evaluation of the fermentation index using undried samples, during the process. © 2013 Society of Chemical Industry.

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

NARCIS (Netherlands)

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

2009-01-01

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

Efficient fermentation of xylose to ethanol at high formic acid concentrations by metabolically engineered Saccharomyces cerevisiae

Energy Technology Data Exchange (ETDEWEB)

Hasunuma, Tomohisa; Yoshimura, Kazuya; Matsuda, Fumio [Kobe Univ., Hyogo (Japan). Organization of Advanced Science and Technology; Sung, Kyung-mo; Sanda, Tomoya; Kondo, Akihiko [Kobe Univ., Hyogo (Japan). Dept. of Chemical Science and Engineering

2011-05-15

Recombinant yeast strains highly tolerant to formic acid during xylose fermentation were constructed. Microarray analysis of xylose-fermenting Saccharomyces cerevisiae strain overexpressing endogenous xylulokinase in addition to xylose reductase and xylitol dehydrogenase from Pichia stipitis revealed that upregulation of formate dehydrogenase genes (FDH1 and FDH2) was one of the most prominent transcriptional events against excess formic acid. The quantification of formic acid in medium indicated that the innate activity of FDH was too weak to detoxify formic acid. To reinforce the capability for formic acid breakdown, the FDH1 gene was additionally overexpressed in the xylose-metabolizing recombinant yeast. This modification allowed the yeast to rapidly decompose excess formic acid. The yield and final ethanol concentration in the presence of 20 mM formic acid is as essentially same as that of control. The fermentation profile also indicated that the production of xylitol and glycerol, major by-products in xylose fermentation, was not affected by the upregulation of FDH activity. (orig.)

In vitro incorporation of 14C-hexose-6-phosphat in mannan, β-glucan and glycogen of Candida spec. H and their mutants

International Nuclear Information System (INIS)

Roeber, B.; Reuter, G.

1982-01-01

Mannose-6-P is an activator of 14 C-mannose incorporation from GDP- 14 C-mannose in mono- and oligosaccharides and in mannopolymers of the cell wall proteophosphomannan produced by the food protein yeast Candida spec. H. Moreover, mannose-6-P is a precursor of proteophosphomannan: 14 C-mannose-6-P has been incorporated in absence of GTP. Corresponding behavior shows glucose-6-P by synthesis of β-glucan and glycogen. Mutants of Candida spec. H with different efficiency in the biosynthesis of mannan, β-glucan and glycogen incorporate hexose-6-P in a different extent. (author)

Comparison of fermentation of diets of variable composition and microbial populations in the rumen of sheep and Rusitec fermenters. I. Digestibility, fermentation parameters, and microbial growth.

Science.gov (United States)

Martínez, M E; Ranilla, M J; Tejido, M L; Ramos, S; Carro, M D

2010-08-01

Four ruminally and duodenally cannulated sheep and 8 Rusitec fermenters were used to determine the effects of forage to concentrate (F:C) ratio and type of forage in the diet on ruminal fermentation and microbial protein synthesis. The purpose of the study was to assess how closely fermenters can mimic the dietary differences found in vivo. The 4 experimental diets contained F:C ratios of 70:30 or 30:70 with either alfalfa hay or grass hay as the forage. Microbial growth was determined in both systems using (15)N as a microbial marker. Rusitec fermenters detected differences between diets similar to those observed in sheep by changing F:C ratio on pH; neutral detergent fiber digestibility; total volatile fatty acid concentrations; molar proportions of acetate, propionate, butyrate, isovalerate, and caproate; and amylase activity. In contrast, Rusitec fermenters did not reproduce the dietary differences found in sheep for NH(3)-N and lactate concentrations, dry matter (DM) digestibility, proportions of isobutyrate and valerate, carboxymethylcellulase and xylanase activities, and microbial growth and its efficiency. Regarding the effect of the type of forage in the diet, Rusitec fermenters detected differences between diets similar to those found in sheep for most determined parameters, with the exception of pH, DM digestibility, butyrate proportion, and carboxymethylcellulase activity. Minimum pH and maximal volatile fatty acid concentrations were reached at 2h and at 6 to 8h postfeeding in sheep and fermenters, respectively, indicating that feed fermentation was slower in fermenters compared with that in sheep. There were differences between systems in the magnitude of most determined parameters. In general, fermenters showed lower lactate concentrations, neutral detergent fiber digestibility, acetate:propionate ratios, and enzymatic activities. On the contrary, fermenters showed greater NH(3)-N concentrations, DM digestibility, and proportions of propionate

Formation of ethyl carbamate and changes during fermentation and storage of yellow rice wine.

Science.gov (United States)

Wu, Pinggu; Cai, Chenggang; Shen, Xianghong; Wang, Liyuan; Zhang, Jing; Tan, Ying; Jiang, Wei; Pan, Xiaodong

2014-01-01

Ethyl carbamate (EC) was analyzed during yellow rice wine production and storage. EC increased slowly during fermentation and rapidly after frying and sterilization. Less amount of EC was formed when cooled rapidly to 30 °C than when cooled naturally. High temperature and long storage time increased EC formation. After 400 days storage, EC increased from 74.0 to 84.2, 131.8 and 509.4 μg/kg at 4 °C, room temperature and 37 °C, respectively, and there was significantly difference between the fried wine and the wine on sale from 2011 (pwine fermentation and was above 20 mg/kg after the wine was fried; urea contributed to EC formation when the fried wine was cooled slowly. These results indicate that it is necessary for industry to optimize the wine frying conditions, such as temperature, time and cooling process in order to decrease EC formation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Anaerobic digestion in combination with 2nd generation ethanol production for maximizing biofuels yield from lignocellulosic biomass – testing in an integrated pilot-scale biorefinery plant

DEFF Research Database (Denmark)

Uellendahl, Hinrich; Ahring, Birgitte Kiær

An integrated biorefinery concept for 2nd generation bioethanol production together with biogas production from the fermentation effluent was tested in pilot-scale. The pilot plant comprised pretreatment, enzymatic hydrolysis, hexose and pentose fermentation into ethanol and anaerobic digestion......-VS/(m3•d) a methane yield of 340 L/kg-VS was achieved for thermophilic operation while 270 L/kg-VS was obtained under mesophilic conditions. Thermophilic operation was, however, less robust towards further increase of the loading rate and for loading rates higher than 5 kg-VS/(m3•d) the yield was higher...... for mesophilic than for thermophilic operation. The effluent from the ethanol fermentation showed no signs of toxicity to the anaerobic microorganisms. Implementation of the biogas production from the fermentation effluent accounted for about 30% higher biofuels yield in the biorefinery compared to a system...

Dilute H{sub 2}SO{sub 4}-catalyzed hydrothermal pretreatment to enhance enzymatic digestibility of Jatropha curcas fruit hull for ethanol fermentation

Energy Technology Data Exchange (ETDEWEB)

Marasabessy, Ahmad [Wageningen Univ. (Netherlands). Agrotechnology and Food Sciences Group; Rijksuniversiteit Groningen (Netherlands). Dept. of Chemical Engineering; Agency for the Assessment and Application of Technology (BPPT), Jakarta (Indonesia); Kootstra, A. Maarten J. [Wageningen Univ. (Netherlands). Agrotechnology and Food Sciences Group; Wageningen Univ. (Netherlands). Bioprocess Engineering Group; Sanders, Johan P.M.; Westhuis, Ruud A. [Wageningen Univ. (Netherlands). Agrotechnology and Food Sciences Group

2012-11-01

Dilute sulfuric acid pretreatment of the Jatropha curcas fruit hull at high temperatures (140 C to 180 C) performed in a 110-mL stainless steel reactor was investigated to enhance the enzymatic digestibility of its lignocellulosic components. Carbohydrates accounted for 43% of the dry matter of the J. curcas fruit hull biomass. The goal of the study was to optimize the pretreatment conditions (acid concentration, time, and temperature) in order to obtain the highest sugar yield after subsequent enzymatic hydrolysis. A Box-Behnken design was applied to the experimental setup in order to reduce the number of experiments. The optimal pretreatment conditions are 30-min incubations at a temperature of 178 C with a sulfuric acid concentration of 0.9% (w/v). Using these pretreatment conditions for a fruit solid loading of 9.52% followed by a 24-h enzymatic hydrolysis resulted in a liberation of 100% of all pentoses present (71% yield and 29% degradation to furfural) and 83% of the hexoses (78% yield and 5% degradation to 5-hydroxymethylfurfural). The simultaneous saccharification and fermentation experiment showed that acid-pretreated fruit hull can be used as a substrate for Saccharomyces cerevisiae to produce ethanol. (orig.)

TRADITIONAL FERMENTED FOODS OF LESOTHO

Directory of Open Access Journals (Sweden)

Tendekayi H. Gadaga

2013-06-01

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

Fermentation of sugar-beet molasses

Energy Technology Data Exchange (ETDEWEB)

Malchenko, A L; Krishtul, F B

1956-08-25

Sugar-beet molasses is fermented with yeast separated from the mash, sterilized, and reactivated. To reduce sugar losses and hasten fermentation, the yeast is removed from the mash as the cells fall to the bottom during the fermentation process.

Reevaluation of the phenol-sulfuric acid reaction for the estimation of hexoses and pentoses.

Science.gov (United States)

Rao, P; Pattabiraman, T N

1989-08-15

Evidence is provided to show that in the conventional phenol-sulfuric acid reaction procedure, phenol underwent sulfonation in situ and the phenolsulfonic acid formed decreased the color intensity for hydroxymethyl furfural (HMF), furfural, and many hexoses and pentoses tested. A modified method is described to overcome this problem in which phenol was added after the dehydration of carbohydrates by sulfuric acid and after cooling the system. The color intensity around 475-485 nm for different compounds was fairly proportional to the amount of furfural derivatives (absorption at 310-320 nm) formed from the sugars in the modified method unlike in the conventional procedure. The studies also show that for condensation of HMF derivatives with phenol, heat is not necessary. The color intensity in the modified method also increased compared to that in the conventional method. The increase in the modified method compared to that in the conventional method was 6.0-fold for furfural, 9.1-fold for hydroxymethyl furfural, 3.7-fold for fructose, 2.3-fold for xylose, and 2.0-fold for glucose and arabinose. The possible reasons for this differential increase are discussed.

Effect of Cultivar, Temperature, and Environmental Conditions on the Dynamic Change of Melatonin in Mulberry Fruit Development and Wine Fermentation.

Science.gov (United States)

Wang, Cheng; Yin, Li-Yuan; Shi, Xue-Ying; Xiao, Hua; Kang, Kun; Liu, Xing-Yan; Zhan, Ji-Cheng; Huang, Wei-Dong

2016-04-01

High levels of melatonin have been reported in various foods but not in mulberry or its wine. This study investigated the dynamic changes of melatonin levels during mulberry fruit development and ethanol fermentation of 2 different colored mulberry cultivars ("Hongguo2ˮ Morus nigra, black and "Baiyuwangˮ Morus alba, white) at 2 fermentation temperatures (16 and 25 °C). Our results showed that the melatonin level increased in the beginning of mulberry development but decreased in the end. The MnTDC gene expression level correlated with melatonin production, which implied that TDC may be the rate-limiting enzyme of the melatonin biosynthetic process in mulberries. During mulberry fermentation, the melatonin concentration increased rapidly in the beginning and then decreased gradually. Low temperature delayed the melatonin production during fermentation. A relatively high level of melatonin was found in "Hongguo2ˮ compared with "Baiyuwangˮ during fruit development and fermentation. The variation of melatonin correlated with the ethanol production rate, suggesting that melatonin may participate in physiological regulation of Saccharomyces cerevisiae during the fermentation stage. © 2016 Institute of Food Technologists®

Food Technologies: Fermentation

NARCIS (Netherlands)

Nout, M.J.R.

2014-01-01

Fermentation refers to the use of microorganisms to achieve desirable food properties in the fermented food or beverage. Although the word ‘fermentation’ indicates ‘anaerobic metabolism,’ it is also used in a broader sense to indicate all anaerobic and aerobic microbiological and biochemical

Effects of three methane mitigation agents on parameters of kinetics of total and hydrogen gas production, ruminal fermentation and hydrogen balance using in vitro technique.

Science.gov (United States)

Wang, Min; Wang, Rong; Yang, Shan; Deng, Jin Ping; Tang, Shao Xun; Tan, Zhi Liang

2016-02-01

Methane (CH4 ) can be mitigated through directly inhibiting methanogen activity and starving methanogens by hydrogen (H2 ) sink. Three types of mechanism (i.e. bromoethanesulphonate (BES), nitrate and emodin) and doses of CH4 mitigation agents were employed to investigate their pathways of CH4 inhibition. Results indicated that both BES and emodin inhibited CH4 production and altered H2 balance, which could be accompanied by decreased dry matter disappearance (DMD), fractional rate of gH2 formation, volatile fatty acid (VFA) production, ability to produce and use reducing equivalences and molecular H2 , and increased final asymptotic gH2 production, time to the peak of gH2 , discrete lag time of gH2 production and fermentation efficiency. However, emodin decreased gas volume produced by rapidly fermentable components of substrate and the rate of fermentation at early stage of incubation, while BES supplementation inhibited gas volume produced by both rapidly and slowly fermentable components of substrate and the rate of fermentation at middle or late stage of incubation. The nitrate supplementation inhibited CH4 production without affecting VFA profile, because of its dual role as H2 sink and being toxic to methanogens. Nitrate supplementation had more complicated pattern of fermentation, VFA production and profile and H2 balance in comparison to BES and emodin supplementation. © 2015 Japanese Society of Animal Science.

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.

Xylose fermentation to ethanol

Energy Technology Data Exchange (ETDEWEB)

McMillan, J.D.

1993-01-01

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

The Brewing Process: Optimizing the Fermentation

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Teodora Coldea

2014-11-01

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

Competition between pentoses and glucose during uptake and catabolism in recombinant Saccharomyces cerevisiae

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Subtil Thorsten

2012-03-01

Full Text Available Abstract Background In mixed sugar fermentations with recombinant Saccharomyces cerevisiae strains able to ferment D-xylose and L-arabinose the pentose sugars are normally only utilized after depletion of D-glucose. This has been attributed to competitive inhibition of pentose uptake by D-glucose as pentose sugars are taken up into yeast cells by individual members of the yeast hexose transporter family. We wanted to investigate whether D-glucose inhibits pentose utilization only by blocking its uptake or also by interfering with its further metabolism. Results To distinguish between inhibitory effects of D-glucose on pentose uptake and pentose catabolism, maltose was used as an alternative carbon source in maltose-pentose co-consumption experiments. Maltose is taken up by a specific maltose transport system and hydrolyzed only intracellularly into two D-glucose molecules. Pentose consumption decreased by about 20 - 30% during the simultaneous utilization of maltose indicating that hexose catabolism can impede pentose utilization. To test whether intracellular D-glucose might impair pentose utilization, hexo-/glucokinase deletion mutants were constructed. Those mutants are known to accumulate intracellular D-glucose when incubated with maltose. However, pentose utilization was not effected in the presence of maltose. Addition of increasing concentrations of D-glucose to the hexo-/glucokinase mutants finally completely blocked D-xylose as well as L-arabinose consumption, indicating a pronounced inhibitory effect of D-glucose on pentose uptake. Nevertheless, constitutive overexpression of pentose-transporting hexose transporters like Hxt7 and Gal2 could improve pentose consumption in the presence of D-glucose. Conclusion Our results confirm that D-glucose impairs the simultaneous utilization of pentoses mainly due to inhibition of pentose uptake. Whereas intracellular D-glucose does not seem to have an inhibitory effect on pentose utilization

27 CFR 24.197 - Production by fermentation.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Production by fermentation... fermentation. In producing special natural wine by fermentation, flavoring materials may be added before or during fermentation. Special natural wine produced by fermentation may be ameliorated in the same manner...

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...

Biohydrogen production by anaerobic fermentation of waste. Final project report

Energy Technology Data Exchange (ETDEWEB)

Karakashev, D.; Angelidaki, I.

2009-01-15

The objective of this project was to investigate and increase dark fermentative hydrogen production from organic wastes by optimizing important process parameters (reactor type, pH, temperature, organic loading, retention time, inoculation strategy, microbial composition). Labscale experiments were carried out at the Department of Environmental Engineering, Technical University of Denmark. A two steps process for hydrogen production in the first step and methane production in the second step in serial connected fully mixed reactors was developed and could successfully convert organic matter to approx. 20-25 % hydrogen and 15-80 % to methane. Sparging with methane produced in the second stage could significantly increase the hydrogen production. Additionally it was shown that upflow anaerobic sludge blanket (UASB) reactor system was very promising for high effective biohydrogen production from glucose at 70 deg C. Glucose-fed biofilm reactors filled with plastic carriers demonstrated high efficient extreme thermophilic biohydrogen production with mixed cultures. Repeated batch cultivations via exposure of the cultures to increased concentrations of household solid waste was found to be most useful method to enhance hydrogen production rate and reduce lag phase of extreme thermophilic fermentation process. Low level of pH (5.5) at 3-day HRT was enough to inhibit completely the methanogenesis and resulted in stable extreme thermophilic hydrogen production. Homoacetogenisis was proven to be an alternative competitor to biohydrogen production from organic acids under thermophilic (55 deg. C) conditions. With respect to microbiology, 16S rRNA targeted oligonucleotide probes were designed to monitor the spatial distribution of hydrogen producing bacteria in sludge and granules from anaerobic reactors. An extreme thermophilic (70 deg. C), strict anaerobic, mixed microbial culture with high hydrogen producing potential was enriched from digested household waste. Culture

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

Directory of Open Access Journals (Sweden)

Ogueke, C. C.

2013-12-01

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

Saccharomyces cerevisiae KNU5377 stress response during high-temperature ethanol fermentation.

Science.gov (United States)

Kim, Il-Sup; Kim, Young-Saeng; Kim, Hyun; Jin, Ingnyol; Yoon, Ho-Sung

2013-03-01

Fuel ethanol production is far more costly to produce than fossil fuels. There are a number of approaches to cost-effective fuel ethanol production from biomass. We characterized stress response of thermotolerant Saccharomyces cerevisiae KNU5377 during glucose-based batch fermentation at high temperature (40°C). S. cerevisiae KNU5377 (KNU5377) transcription factors (Hsf1, Msn2/4, and Yap1), metabolic enzymes (hexokinase, glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, and alcohol dehydrogenase), antioxidant enzymes (thioredoxin 3, thioredoxin reductase, and porin), and molecular chaperones and its cofactors (Hsp104, Hsp82, Hsp60, Hsp42, Hsp30, Hsp26, Cpr1, Sti1, and Zpr1) are upregulated during fermentation, in comparison to S. cerevisiae S288C (S288C). Expression of glyceraldehyde-3-phosphate dehydrogenase increased significantly in KNU5377 cells. In addition, cellular hydroperoxide and protein oxidation, particularly lipid peroxidation of triosephosphate isomerase, was lower in KNU5377 than in S288C. Thus, KNU5377 activates various cell rescue proteins through transcription activators, improving tolerance and increasing alcohol yield by rapidly responding to fermentation stress through redox homeostasis and proteostasis.

Fermentative alcohol production

Science.gov (United States)

Wilke, Charles R.; Maiorella, Brian L.; Blanch, Harvey W.; Cysewski, Gerald R.

1982-01-01

An improved fermentation process for producing alcohol which includes the combination of vacuum fermentation and vacuum distillation. Preferably, the vacuum distillation is carried out in two phases, one a fermentor proper operated at atmospheric pressure and a flash phase operated at reduced pressure with recycle of fermentation brew having a reduced alcohol content to the fermentor, using vapor recompression heating of the flash-pot recycle stream to heat the flash-pot or the distillation step, and using "water load balancing" (i.e., the molar ratio of water in the fermentor feed is the same as the molar ratio of water in the distillation overhead).

Freezing of meat raw materials affects tyramine and diamine accumulation in spontaneously fermented sausages.

Science.gov (United States)

Bover-Cid, Sara; Miguelez-Arrizado, M Jesús; Luz Latorre Moratalla, L; Vidal Carou, M Carmen

2006-01-01

Biogenic amine accumulation was studied in spontaneously fermented sausages (Fuet) manufactured from unfrozen-fresh meat (U-sausages) and frozen-thawed meat (F-sausages). The aim was to investigate whether the frozen storage of raw materials affects the microbial composition and its aminogenic activity during sausage fermentation. Tyramine was the major amine in all sausages. Although the final levels were similar, tyramine accumulated more rapidly in F-sausages, which contained putrescine as the second amine. By contrast, U-sausages accumulated much more cadaverine than putrescine. F-sausages showed a slightly lower pH and free amino acid content as well as higher counts of technological flora (lactic acid and gram positive catalase positive bacteria) and lower counts of enterobacteria. Therefore, to freeze the meat raw materials for few days before sausage manufacture could be a useful practice, especially for the artisan fermented sausages (without starter), because it helps to reduce enterobacteria development and cadaverine production.

Rapid Quantification of Major Volatile Metabolites in Fermented Food and Beverages Using Gas Chromatography-Mass Spectrometry.

Science.gov (United States)

Pinu, Farhana R; Villas-Boas, Silas G

2017-07-26

Here we present a method for the accurate quantification of major volatile metabolites found in different food and beverages, including ethanol, acetic acid and other aroma compounds, using gas chromatography coupled to mass spectrometry (GC-MS). The method is combined with a simple sample preparation procedure using sodium chloride and anhydrous ethyl acetate. The GC-MS analysis was accomplished within 4.75 min, and over 80 features were detected, of which 40 were positively identified using an in-house and a commercialmass spectrometry (MS) library. We determined different analytical parameters of these metabolites including the limit of detection (LOD), limit of quantitation (LOQ) and range of quantification. In order to validate the method, we also determined detailed analytical characteristics of five major fermentation end products including ethanol, acetic acid, isoamyl alcohol, ethyl-L-lactate and, acetoin. The method showed very low technical variability for the measurements of these metabolites in different matrices (<3%) with an excellent accuracy (100% ± 5%), recovery (100% ± 10%), reproducibility and repeatability [Coefficient of variation (CV) 1-10%)]. To demonstrate the applicability of the method, we analysed different fermented products including balsamic vinegars, sourdough, distilled (whisky) and non-distilled beverages (wine and beer).

Commercial Biomass Syngas Fermentation

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James Daniell

2012-12-01

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

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

International Nuclear Information System (INIS)

Estela Escalante, Waldir D; Rychtera, Mojmir; Melzoch, Karel; Guerrero Ochoa, Manuel R

2012-01-01

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

Low-Carbon Fuel and Chemical Production by Anaerobic Gas Fermentation.

Science.gov (United States)

Daniell, James; Nagaraju, Shilpa; Burton, Freya; Köpke, Michael; Simpson, Séan Dennis

World energy demand is expected to increase by up to 40% by 2035. Over this period, the global population is also expected to increase by a billion people. A challenge facing the global community is not only to increase the supply of fuel, but also to minimize fossil carbon emissions to safeguard the environment, at the same time as ensuring that food production and supply is not detrimentally impacted. Gas fermentation is a rapidly maturing technology which allows low carbon fuel and commodity chemical synthesis. Unlike traditional biofuel technologies, gas fermentation avoids the use of sugars, relying instead on gas streams rich in carbon monoxide and/or hydrogen and carbon dioxide as sources of carbon and energy for product synthesis by specialized bacteria collectively known as acetogens. Thus, gas fermentation enables access to a diverse array of novel, large volume, and globally available feedstocks including industrial waste gases and syngas produced, for example, via the gasification of municipal waste and biomass. Through the efforts of academic labs and early stage ventures, process scale-up challenges have been surmounted through the development of specialized bioreactors. Furthermore, tools for the genetic improvement of the acetogenic bacteria have been reported, paving the way for the production of a spectrum of ever-more valuable products via this process. As a result of these developments, interest in gas fermentation among both researchers and legislators has grown significantly in the past 5 years to the point that this approach is now considered amongst the mainstream of emerging technology solutions for near-term low-carbon fuel and chemical synthesis.

An obligately aerobic soil bacterium activates fermentative hydrogen production to survive reductive stress during hypoxia.

Science.gov (United States)

Berney, Michael; Greening, Chris; Conrad, Ralf; Jacobs, William R; Cook, Gregory M

2014-08-05

Oxygen availability is a major factor and evolutionary force determining the metabolic strategy of bacteria colonizing an environmental niche. In the soil, conditions can switch rapidly between oxia and anoxia, forcing soil bacteria to remodel their energy metabolism accordingly. Mycobacterium is a dominant genus in the soil, and all its species are obligate aerobes. Here we show that an obligate aerobe, the soil actinomycete Mycobacterium smegmatis, adopts an anaerobe-type strategy by activating fermentative hydrogen production to adapt to hypoxia. This process is controlled by the two-component system DosR-DosS/DosT, an oxygen and redox sensor that is well conserved in mycobacteria. We show that DosR tightly regulates the two [NiFe]-hydrogenases: Hyd3 (MSMEG_3931-3928) and Hyd2 (MSMEG_2719-2718). Using genetic manipulation and high-sensitivity GC, we demonstrate that Hyd3 facilitates the evolution of H2 when oxygen is depleted. Combined activity of Hyd2 and Hyd3 was necessary to maintain an optimal NAD(+)/NADH ratio and enhanced adaptation to and survival of hypoxia. We demonstrate that fermentatively-produced hydrogen can be recycled when fumarate or oxygen become available, suggesting Mycobacterium smegmatis can switch between fermentation, anaerobic respiration, and aerobic respiration. Hydrogen metabolism enables this obligate aerobe to rapidly meet its energetic needs when switching between microoxic and anoxic conditions and provides a competitive advantage in low oxygen environments.

The Application of State-of-the-Art Analytic Tools (Biosensors and Spectroscopy in Beverage and Food Fermentation Process Monitoring

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Shaneel Chandra

2017-09-01

Full Text Available The production of several agricultural products and foods are linked with fermentation. Traditional methods used to control and monitor the quality of the products and processes are based on the use of simple chemical analysis. However, these methods are time-consuming and do not provide sufficient relevant information to guarantee the chemical changes during the process. Commonly used methods applied in the agriculture and food industries to monitor fermentation are those based on simple or single-point sensors, where only one parameter is measured (e.g., temperature or density. These sensors are used several times per day and are often the only source of data available from which the conditions and rate of fermentation are monitored. In the modern food industry, an ideal method to control and monitor the fermentation process should enable a direct, rapid, precise, and accurate determination of several target compounds, with minimal to no sample preparation or reagent consumption. Here, state-of-the-art advancements in both the application of sensors and analytical tools to monitor beverage and food fermentation processes will be discussed.

High Production of 2,3-Butanediol (2,3-BD by Raoultella ornithinolytica B6 via Optimizing Fermentation Conditions and Overexpressing 2,3-BD Synthesis Genes.

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Taeyeon Kim

Full Text Available Biological production of 2,3-butandiol (2,3-BD has received great attention as an alternative to the petroleum-based 2,3-BD production. In this study, a high production of 2,3-BD in fed-batch fermentation was investigated with a newly isolated bacterium designated as Raoultella ornithinolytica B6. The isolate produced 2,3-BD as the main product using hexoses (glucose, galactose, and fructose, pentose (xylose and disaccharide (sucrose. The effects of temperature, pH-control schemes, and agitation speeds on 2,3-BD production were explored to optimize the fermentation conditions. Notably, cell growth and 2,3-BD production by R. ornithinolytica B6 were higher at 25°C than at 30°C. When three pH control schemes (no pH control, pH control at 7, and pH control at 5.5 after the pH was decreased to 5.5 during fermentation were tested, the best 2,3-BD titer and productivity along with reduced by-product formation were achieved with pH control at 5.5. Among different agitation speeds (300, 400, and 500 rpm, the optimum agitation speed was 400 rpm with 2,3-BD titer of 68.27 g/L, but acetic acid was accumulated up to 23.32 g/L. Further enhancement of the 2,3-BD titer (112.19 g/L, yield (0.38 g/g, and productivity (1.35 g/L/h as well as a significant reduction of acetic acid accumulation (9.71 g/L was achieved by the overexpression of homologous budABC genes, the 2,3-BD-synthesis genes involved in the conversion of pyruvate to 2,3-BD. This is the first report presenting a high 2,3-BD production by R.ornithinolytica which has attracted little attention with respect to 2,3-BD production, extending the microbial spectrum of 2,3-BD producers.

Research in fermentation

Energy Technology Data Exchange (ETDEWEB)

Mills, A K

1966-01-01

The following aspects of the biochemistry of fermentation were discussed: carbohydrate, amino acid, S, and phosphate metabolisms in the yeast cell; pantothenic acid and biotin as the essential growth factors in yeast metabolisms; effects of different aeration conditions on yeast growth, mitochondria development, and lipid contents. Gas chromatographic studies of fermentation products are also discussed.

Fermented Nut-Based Vegan Food: Characterization of a Home made Product and Scale-Up to an Industrial Pilot-Scale Production.

Science.gov (United States)

Tabanelli, Giulia; Pasini, Federica; Riciputi, Ylenia; Vannini, Lucia; Gozzi, Giorgia; Balestra, Federica; Caboni, Maria Fiorenza; Gardini, Fausto; Montanari, Chiara

2018-03-01

Because of the impossibility to consume food of animal origin, vegan consumers are looking for substitutes that could enrich their diet. Among many substitutes, fermented nut products are made from different nut types and obtained after soaking, grinding, and fermentation. Although other fermented vegetable products have been deeply investigated, there are few data about the fermentative processes of nut-based products and the microbial consortia able to colonize these products are not yet studied. This study characterized a hand-made vegan product obtained from cashew nut. Lactic acid bacteria responsible for fermentation were identified, revealing a succession of hetero- and homo-fermentative species during process. Successively, some lactic acid bacteria isolates from the home-made vegan product were used for a pilot-scale fermentation. The products obtained were characterized and showed features similar to the home-made one, although the microbiological hazards have been prevented through proper and rapid acidification, enhancing their safety features. Spontaneous fermented products are valuable sources of microorganisms that can be used in many food processes as starter cultures. The lactic acid bacteria isolated in this research can be exploited by industries to develop new foods and therefore to enter new markets. The use of selected starter cultures guarantees good organoleptic characteristics and food safety (no growth of pathogens). © 2018 Institute of Food Technologists®.

Korean traditional fermented soybean products: Jang

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Donghwa Shin

2015-03-01

Fermented products are going beyond the boundaries of their use as mere side dishes, and are seeing significant increases in their use as a functional food. Kanjang (fermented soy sauce, Doenjang (fermented soybean paste, and Gochujang (fermented red pepper paste are the most well-known fermented products in Korea. These products occupy an important place in people's daily lives as seasonings and are used in many side dishes. It has been proven through clinical studies that these products have many health benefits, such as their ability to fight cancer and diabetes, and to prevent obesity and constipation.

Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants

DEFF Research Database (Denmark)

Petersen, Pia; Lau, Jane; Ebert, Berit

2012-01-01

Background: Cost-efficient generation of second-generation biofuels requires plant biomass that can easily be degraded into sugars and further fermented into fuels. However, lignocellulosic biomass is inherently recalcitrant toward deconstruction technologies due to the abundant lignin and cross......-linked hemicelluloses. Furthermore, lignocellulosic biomass has a high content of pentoses, which are more difficult to ferment into fuels than hexoses. Engineered plants with decreased amounts of xylan in their secondary walls have the potential to render plant biomass a more desirable feedstock for biofuel production...... in the xylem vessels is sufficient to complement the irx phenotype of xylan deficient mutants, while maintaining low overall amounts of xylan and lignin in the cell wall. This engineering approach has the potential to yield bioenergy crop plants that are more easily deconstructed and fermented into biofuels....

Ethnobotany of wild plants used for starting fermented beverages in Shui communities of southwest China.

Science.gov (United States)

Hong, Liya; Zhuo, Jingxian; Lei, Qiyi; Zhou, Jiangju; Ahmed, Selena; Wang, Chaoying; Long, Yuxiao; Li, Feifei; Long, Chunlin

2015-05-28

Shui communities of southwest China have an extensive history of using wild plants as starters (Xiaoqu) to prepare fermented beverages that serve important roles in interpersonal relationships and cultural events. While the practice of using wild plants as starters for the preparation of fermented beverages was once prevalent throughout China, this tradition has seen a decline nationally since the 1930s. The traditional technique of preparing fermented beverages from wild plant starters remains well preserved in the Shui communities in southwest China and provides insight on local human-environment interactions and conservation of plant biodiversity for cultural purposes. The present study sought to examine the ethnobotany of wild plants used as starters for the preparation of fermented beverages including an inventory of plants used as a starter in liquor fermentation and associated knowledge and practices. Field surveys were carried out that consisted of semi-structured surveys and plant species inventories. One hundred forty-nine informants in twenty Shui villages were interviewed between July 2012 and October 2014 to document knowledge associated with wild plants used as a liquor fermentation starter. The inventories involved plant voucher specimens and taxonomic identification of plant collections. A total of 103 species in 57 botanical families of wild plants were inventoried and documented that are traditionally used as starters for preparing fermented beverages by Shui communities. The majority of the species (93.2%) have multiple uses in addition to being used as a starter with medicinal purposes being the most prevalent. Shui women are the major harvesters and users of wild plants used as starters for preparing fermented beverages and transfer knowledge orally from mother to daughter. Findings from this study can serve as a basis for future investigation on fermented beverages and foods and associated knowledge and cultural practices. However, with rapid

Fermented Broth in Tyrosinase- and Melanogenesis Inhibition

OpenAIRE

Chin-Feng Chan; Ching-Cheng Huang; Ming-Yuan Lee; Yung-Sheng Lin

2014-01-01

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

Protein modification by fermentation

DEFF Research Database (Denmark)

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

1998-01-01

The effect of fermentation on components of potential significance for the allergenicity of pea was analyzed. Pea flour was fermented with three lactic acid bacteria, Pediococcus pentosaceus, Lactococcus raffinolactis, and Lactobacillus plantarum, and two fungi, Rhizopus microsporus, var....... oligosporus and Geotrichum candidum. Residual antigenicity against antipea antibodies was reduced to 10% by the three lactic acid bacteria and R. microsporus. Reactions to anti-pea profilin and anti-Bet v I were still detectable after fermentation. The contents of lectin and pea protease inhibitor were...

Microbial production, ultrasound-assisted extraction and characterization of biopolymer polyhydroxybutyrate (PHB) from terrestrial (P. hysterophorus) and aquatic (E. crassipes) invasive weeds.

Science.gov (United States)

Pradhan, Sushobhan; Borah, Arup Jyoti; Poddar, Maneesh Kumar; Dikshit, Pritam Kumar; Rohidas, Lilendar; Moholkar, Vijayanand S

2017-10-01

This study reports synthesis of biodegradable poly(3-hydroxybutyrate) (PHB) polymer from two invasive weeds, viz. P. hysterophorus and E. crassipes. The pentose and hexose-rich hydrolyzates obtained from acid pretreatment and enzymatic hydrolysis of two biomasses were separately fermented using Ralstonia eutropha MTCC 8320 sp. PHB was extracted using sonication and was characterized using FTIR, 1 H and 13 C NMR and XRD. PHB content of dry cell mass was 8.1-21.6% w/w, and the PHB yield was 6.85×10 -3 -36.41×10 -3 % w/w raw biomass. Thermal properties of PHB were determined by TGA, DTG and DSC analysis. PHB obtained from pentose-hydrolyzate had glass transition temperatures of 6°-9°C, while PHB from hexose-rich hydrolyzate had maximum thermal degradation temperatures of 370°-389°C. These thermal properties were comparable to the properties of commercial PHB. Probable causes leading to differences in thermal properties of pentose and hexose-derived PHB are: extent of crystallinity and presence of impurity in the polymer matrix. Copyright © 2017 Elsevier Ltd. All rights reserved.

Yeasts Diversity in Fermented Foods and Beverages

Science.gov (United States)

Tamang, Jyoti Prakash; Fleet, Graham H.

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

Fermented Broth in Tyrosinase- and Melanogenesis Inhibition

Directory of Open Access Journals (Sweden)

Chin-Feng Chan

2014-08-01

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

High-strength fermentable wastewater reclamation through a sequential process of anaerobic fermentation followed by microalgae cultivation.

Science.gov (United States)

Qi, Wenqiang; Chen, Taojing; Wang, Liang; Wu, Minghong; Zhao, Quanyu; Wei, Wei

2017-03-01

In this study, the sequential process of anaerobic fermentation followed by microalgae cultivation was evaluated from both nutrient and energy recovery standpoints. The effects of different fermentation type on the biogas generation, broth metabolites' composition, algal growth and nutrients' utilization, and energy conversion efficiencies for the whole processes were discussed. When the fermentation was designed to produce hydrogen-dominating biogas, the total energy conversion efficiency (TECE) of the sequential process was higher than that of the methane fermentation one. With the production of hydrogen in anaerobic fermentation, more organic carbon metabolites were left in the broth to support better algal growth with more efficient incorporation of ammonia nitrogen. By applying the sequential process, the heat value conversion efficiency (HVCE) for the wastewater could reach 41.2%, if methane was avoided in the fermentation biogas. The removal efficiencies of organic metabolites and NH 4 + -N in the better case were 100% and 98.3%, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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.

Filamentous Fungi Fermentation

DEFF Research Database (Denmark)

Nørregaard, Anders; Stocks, Stuart; Woodley, John

2014-01-01

Filamentous fungi (including microorganisms such as Aspergillus niger and Rhizopus oryzae) represent an enormously important platform for industrial fermentation. Two particularly valuable features are the high yield coefficients and the ability to secrete products. However, the filamentous...... morphology, together with non-Newtonian rheological properties (shear thinning), result in poor oxygen transfer unless sufficient energy is provided to the fermentation. While genomic research may improve the organisms, there is no doubt that to enable further application in future it will be necessary...... to match such research with studies of oxygen transfer and energy supply to high viscosity fluids. Hence, the implementation of innovative solutions (some of which in principle are already possible) will be essential to ensure the further development of such fermentations....

Aerobic Stability and Effects of Yeasts during Deterioration of Non-fermented and Fermented Total Mixed Ration with Different Moisture Levels

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W. Hao

2015-06-01

Full Text Available The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR. The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted to 400 g/kg (low moisture level, LML, 450 g/kg (medium moisture level, MML, and 500 g/kg (high moisture level, HML, and both non-fermented and 56-d-fermented TMR were subjected to air exposure to determine aerobic stability. Aerobic deterioration resulted in high losses of nutritional components and largely reduced dry matter digestibility. Non-fermented TMR deteriorated during 48 h of air exposure and the HML treatment was more aerobically unstable. On dry matter (DM basis, yeast populations significantly increased from 107 to 1010 cfu/g during air exposure, and Candida ethanolica was the predominant species during deterioration in non-fermented TMR. Fermented TMR exhibited considerable resistance to aerobic deterioration. Spoilage was only observed in the HML treatment and its yeast population increased dramatically to 109 cfu/g DM when air exposure progressed to 30 d. Zygosaccharomyces bailii was the sole yeast species isolated when spoilage occurred. These results confirmed that non-fermented and fermented TMR with a HML are more prone to spoilage, and fermented TMR has considerable resistance to aerobic deterioration. Yeasts can trigger aerobic deterioration in both non-fermented and fermented TMR. C. ethanolica may be involved in the spoilage of non-fermented TMR and the vigorous growth of Z. bailii can initiate aerobic deterioration in fermented TMR.

Aerobic Stability and Effects of Yeasts during Deterioration of Non-fermented and Fermented Total Mixed Ration with Different Moisture Levels.

Science.gov (United States)

Hao, W; Wang, H L; Ning, T T; Yang, F Y; Xu, C C

2015-06-01

The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR). The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted to 400 g/kg (low moisture level, LML), 450 g/kg (medium moisture level, MML), and 500 g/kg (high moisture level, HML), and both non-fermented and 56-d-fermented TMR were subjected to air exposure to determine aerobic stability. Aerobic deterioration resulted in high losses of nutritional components and largely reduced dry matter digestibility. Non-fermented TMR deteriorated during 48 h of air exposure and the HML treatment was more aerobically unstable. On dry matter (DM) basis, yeast populations significantly increased from 10(7) to 10(10) cfu/g during air exposure, and Candida ethanolica was the predominant species during deterioration in non-fermented TMR. Fermented TMR exhibited considerable resistance to aerobic deterioration. Spoilage was only observed in the HML treatment and its yeast population increased dramatically to 10(9) cfu/g DM when air exposure progressed to 30 d. Zygosaccharomyces bailii was the sole yeast species isolated when spoilage occurred. These results confirmed that non-fermented and fermented TMR with a HML are more prone to spoilage, and fermented TMR has considerable resistance to aerobic deterioration. Yeasts can trigger aerobic deterioration in both non-fermented and fermented TMR. C. ethanolica may be involved in the spoilage of non-fermented TMR and the vigorous growth of Z. bailii can initiate aerobic deterioration in fermented TMR.

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

Rapid Quantification of Major Volatile Metabolites in Fermented Food and Beverages Using Gas Chromatography-Mass Spectrometry

Directory of Open Access Journals (Sweden)

Farhana R. Pinu

2017-07-01

Full Text Available Here we present a method for the accurate quantification of major volatile metabolites found in different food and beverages, including ethanol, acetic acid and other aroma compounds, using gas chromatography coupled to mass spectrometry (GC-MS. The method is combined with a simple sample preparation procedure using sodium chloride and anhydrous ethyl acetate. The GC-MS analysis was accomplished within 4.75 min, and over 80 features were detected, of which 40 were positively identified using an in-house and a commercialmass spectrometry (MS library. We determined different analytical parameters of these metabolites including the limit of detection (LOD, limit of quantitation (LOQ and range of quantification. In order to validate the method, we also determined detailed analytical characteristics of five major fermentation end products including ethanol, acetic acid, isoamyl alcohol, ethyl-L-lactate and, acetoin. The method showed very low technical variability for the measurements of these metabolites in different matrices (<3% with an excellent accuracy (100% ± 5%, recovery (100% ± 10%, reproducibility and repeatability [Coefficient of variation (CV 1–10%]. To demonstrate the applicability of the method, we analysed different fermented products including balsamic vinegars, sourdough, distilled (whisky and non-distilled beverages (wine and beer.

Tempeh: a mold-modified indigenous fermented food made from soybeans and/or cereal grains.

Science.gov (United States)

Hachmeister, K A; Fung, D Y

1993-01-01

A variety of indigenous fermented foods exist today; however, tempeh has been one of the most widely accepted and researched mold-modified fermented products. Tempeh is a traditional fermented food made from soaked and cooked soybeans inoculated with a mold, usually of the genus Rhizopus. After fermentation has occurred, the soybeans are bound together into a compact cake by dense cottony mycelium. An important function of the mold in the fermentation process is the synthesis of enzymes, which hydrolyze soybean constituents and contribute to the development of a desirable texture, flavor, and aroma of the product. Enzymatic hydrolysis also may decrease or eliminate antinutritional constituents; consequently, the nutritional quality of the fermented product may be improved. Current technology and new scientific advancements have enabled researchers to examine specific strains of Rhizopus and new substrates such as cereal grains. Because Kansas produces numerous cereal grains, production of a fermented tempeh-like product using wheat, sorghum (milo), oats, rye, barley, corn, and triticale is a definite possibility for generating a Kansas Value-Added Product. In this study, several different tempeh-like products were produced using various cereal grains inoculated with Rhizopus oligosporus NRRL 2549 or R. oligosporus NRRL 2710. Grains used included hard red winter wheat, triticale, yellow sorghum (milo), and red sorghum (milo). The grain source as well as the strain of R. oligosporus used influenced the product's appearance, flavor, and patty integrity. Results showed that R. oligosporus NRRL 2549 produced more mycelium at a more rapid rate than did the R. oligosporus NRRL 2710 strain. The combination of red sorghum and R. oligosporus NRRL 2549 yielded a product with good patty texture, aroma, and appearance. Furthermore, the red sorghum fermented product was well suited for slicing. On the other hand, yellow sorghum inoculated with either R. oligosporus NRRL 2549 or

Studies on continuous fermentation

Energy Technology Data Exchange (ETDEWEB)

Ueda, K

1958-01-01

Continuous fermentation of molasses with a combined system of agitated vessel and flow pipe is studied. A new apparatus was designed. The rate of the fermentation was faster with this apparatus than with the former apparatus which was composed of two vessels.

Fermented milk for hypertension

DEFF Research Database (Denmark)

Usinger, Lotte; Reimer, Christina; Ibsen, Hans

2012-01-01

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

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.

Anaerobic fermentation of beef cattle manure. Final report

Energy Technology Data Exchange (ETDEWEB)

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

1981-01-01

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

Improvements In Ethanologenic Escherichia Coli and Klebsiella Oxytoca

Energy Technology Data Exchange (ETDEWEB)

Dr. David Nunn

2010-09-30

The current Verenium cellulosic ethanol process is based on the dilute-acid pretreatment of a biomass feedstock, followed by a two-stage fermentation of the pentose sugar-containing hydrolysate by a genetically modified ethanologenic Escherichia coli strain and a separate simultaneous saccharification-fermentation (SSF) of the cellulosic fraction by a genetically modified ethanologenic Klebsiella oxytoca strain and a fungal enzyme cocktail. In order to reduce unit operations and produce a fermentation beer with higher ethanol concentrations to reduce distillation costs, we have proposed to develop a simultaneous saccharification co-fermentation (SScF) process, where the fermentation of the pentose-containing hydrolysate and cellulosic fraction occurs within the same fermentation vessel. In order to accomplish this goal, improvements in the ethanologens must be made to address a number of issues that arise, including improved hydrolysate tolerance, co-fermentation of the pentose and hexose sugars and increased ethanol tolerance. Using a variety of approaches, including transcriptomics, strain adaptation, metagenomics and directed evolution, this work describes the efforts of a team of scientists from Verenium, University of Florida, Massachusetts Institute of Technology and Genomatica to improve the E. coli and K. oxytoca ethanologens to meet these requirements.

Yeast ecology of Kombucha fermentation.

Science.gov (United States)

Teoh, Ai Leng; Heard, Gillian; Cox, Julian

2004-09-01

Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and physiological tests. During the fermentation of each of the four products, yeasts were enumerated from both the cellulosic pellicle and liquor of the Kombucha. The number and diversity of species varied between products, but included Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii and Zygosaccharomyces bailii. While these yeast species are known to occur in Kombucha, the enumeration of each species present throughout fermentation of each of the four Kombucha cultures demonstrated for the first time the dynamic nature of the yeast ecology. Kombucha fermentation is, in general, initiated by osmotolerant species, succeeded and ultimately dominated by acid-tolerant species.

Antioxidant Activities of Lactic Acid Bacteria for Quality Improvement of Fermented Sausage.

Science.gov (United States)

Zhang, Yulong; Hu, Ping; Lou, Lijiao; Zhan, Jianlong; Fan, Min; Li, Dan; Liao, Qianwei

2017-12-01

Lactobacillus curvatus (SR6) and Lactobacillus paracasei (SR10-1) were assessed for their antioxidant activities and inoculated into sausages to investigate their effects on quality during fermentation. The results showed that L. curvatus SR6 had better DPPH• scavenging activity (59.67% ± 6.68%) and reducing power (47.31% ± 4.62%) and L. paracasei SR10-1 had better OH• scavenging activity (285.67% ± 2.00%) and anti-lipid peroxidation capacity (63.89% ± 0.93%). The superoxide dismutase activity of the cell culture fluid was greater than 47.00 U/mL, and the catalase activity of the cell-free extracts was greater than 1.00 U/mL. In the sausage model, lactic acid bacteria rapidly became the dominant microflora and reduced the moisture content, water activity, nitrite, and pH. The bacteria significantly enhanced the antioxidant activity of the sausage extracts, which improved the sensory characteristics and safety of the sausages. These results illustrate that both strains have excellent antioxidant activities and can be used as antioxidant starters in fermented meat products. The study illustrated the antioxidant and antioxidase activities of Lactobacillus curvatus SR6 and Lactobacillus paracasei SR10-1 and demonstrated the changes in the quality characteristics and antioxidant activities of fermented sausages. The findings provide valuable information for the meat industry on the application of functional starters in fermented meat products. © 2017 Institute of Food Technologists®.

Yeasts are essential for cocoa bean fermentation.

Science.gov (United States)

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

2014-03-17

Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality. Cocoa bean fermentations were conducted with the addition of 200ppm Natamycin to inhibit the growth of yeasts, and the resultant microbial ecology and metabolism, bean chemistry and chocolate quality were compared with those of normal (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii and Kluyveromyces marxianus, the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in the control fermentation. In fermentations with the presence of Natamycin, the same bacterial species grew but yeast growth was inhibited. Physical and chemical analyses showed that beans fermented without yeasts had increased shell content, lower production of ethanol, higher alcohols and esters throughout fermentation and lesser presence of pyrazines in the roasted product. Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

[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.

Cupriavidus necator JMP134 rapidly reduces furfural with a Zn-dependent alcohol dehydrogenase.

Science.gov (United States)

Li, Qunrui; Metthew Lam, L K; Xun, Luying

2011-11-01

Ethanol is a renewable biofuel, and it can be produced from lignocellulosic biomass. The biomass is usually converted to hydrolysates that consist of sugar and sugar derivatives, such as furfural. Yeast ferments sugar to ethanol, but furfural higher than 3 mM is inhibitory. It can take several days for yeast cells to reduce furfural to non-inhibitory furfuryl alcohol before producing ethanol. Bioreduction of furfural to furfuryl alcohol before fermentation may relieve yeast from furfural toxicity. We observed that Cupriavidus necator JMP134, a strict aerobe, rapidly reduced 17 mM furfural to less than 3 mM within 14 min with cell turbidity of 1.0 at 600 nm at 50°C. The rapid reduction consumed ethanol. The "furfural reductase" (FurX) was purified, and it oxidized ethanol to acetaldehyde and reduced furfural to furfuryl alcohol with NAD(+) as the cofactor. The protein was identified with mass spectrometry fingerprinting to be a hypothetical protein belonging to Zn-dependent alcohol dehydrogenase family. The furX-inactivation mutant of C. necator JMP134 lost the ability to rapidly reduce furfural, and Escherichia coli producing recombinant FurX gained the ability. Thus, an alcohol dehydrogenase enabled bacteria to rapidly reduce furfural with ethanol as the reducing power.

Influence of nitrogen sources on growth and fermentation performance of different wine yeast species during alcoholic fermentation

DEFF Research Database (Denmark)

Kemsawasd, Varongsiri; Monteiro Lomba Viana, Tiago; Ardö, Ylva

2015-01-01

-Saccharomyces yeast species (Lachancea thermotolerans, Metschnikowia pulcherrima, Hanseniaspora uvarum and Torulaspora delbrueckii) was investigated during alcoholic fermentation. Briefly, the N-sources with beneficial effects on all performance parameters (or for the majority of them) for each yeast species were...... for L. thermotolerans, H. uvarum and M. pulcherrima, single amino acids affected growth and fermentation performance to the same extent as the mixtures. Moreover, we found groups of N-sources with similar effects on the growth and/or fermentation performance of two or more yeast species. Finally...... species under oxygen-limited conditions, which, in turn, may be used to, e.g. optimize growth and fermentation performance of the given yeast upon N-source supplementation during wine fermentations....

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.

Low energy Kombucha fermented milk-based beverages

Directory of Open Access Journals (Sweden)

Milanović Spasenija D.

2008-01-01

Full Text Available This paper investigates manufacturing of fermented beverages from two types of milk (1 % w/w and 2.2 % w/w fat by applying of Kombucha, which contains several yeasts and bacterial strains. The starter was the inoculum produced from previous Kombucha fermentation. The applied starter concentrations were: 10 % v/v, 15 % v/v and 20 % v/v. Also, the traditional yoghurt starter was used to produce the control samples. All fermentations were performed at 42oC and the changes in the pH were monitored. The fermentation process was about three times faster in the control yoghurt than in the Kombucha samples. Influence of Kombucha inoculum concentration on the rate of fermentation appeared not to be significant. All fermentations were stopped when the pH reached 4.4. After the production, the quality of the fermented milk beverages with Kombucha was determined and compared with the quality of the control yoghurt samples. It was concluded that the difference in fat contents in milks affects the difference in quantities of other components in the fermented milk beverages with Kombucha. Sensory characteristics of the beverages manufactured from the partially skimmed milk are much better than those of the fermented beverages produced from the low fat milk.

Asian fungal fermented food

NARCIS (Netherlands)

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

2010-01-01

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

Macroscopic modelling of solid-state fermentation

NARCIS (Netherlands)

Hoogschagen, M.J.

2007-01-01

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

Continuous alcoholic fermentation of molasses

Energy Technology Data Exchange (ETDEWEB)

Kazimierz, J

1962-01-01

The first Polish plant for ontinuous alcohol fermentation of molasses is described. Continuous fermentation permits a better use of the installation, automatic control, and shorter fermentation time. It yields more CO/sub 2/ for dry ice manufacture and decreases corrosion of apparatus. From 22 to 24% mash is used, giving a yield of 61.1 of 100-proof alc./kg. sucrose and an average of 37 kg. of dry yeast/1000 l. alcohol

Why solid-state fermentation is more advantageous over submerged fermentation for converting high concentration of glycerol into Monacolin K by Monascus purpureus 9901: A mechanistic study.

Science.gov (United States)

Zhang, Bo-Bo; Lu, Li-Ping; Xu, Gan-Rong

2015-07-20

The underlying mechanisms by which solid-state fermentation (SSF) was more advantageous over submerged fermentation (SmF) for converting high concentration of glycerol into Monacolin K by Monascus purpureus were investigated innovatively. First, the established kinetic models and kinetic parameters showed that the cell growth, Monacolin K formation and glycerol consumption in SSF were more rapid than those in SmF. Secondly, the comparison of fatty acid composition of mycelial cells indicated a better fluidity and permeability of the cell membrane in SSF than that of SmF, which was also consistent with the difference in the ratio of extracellular/intracellular Monacolin K between the two systems. Thirdly, the phenomenon of glycerol concentration gradient was verified in SSF, which could well explain the resistance effect to high concentration of glycerol in SSF. These new findings provide some important insights to the elucidation of the advantages of SSF for the synthesis of fungal secondary metabolites. Copyright © 2015 Elsevier B.V. All rights reserved.

A modified indirect mathematical model for evaluation of ethanol production efficiency in industrial-scale continuous fermentation processes.

Science.gov (United States)

Canseco Grellet, M A; Castagnaro, A; Dantur, K I; De Boeck, G; Ahmed, P M; Cárdenas, G J; Welin, B; Ruiz, R M

2016-10-01

To calculate fermentation efficiency in a continuous ethanol production process, we aimed to develop a robust mathematical method based on the analysis of metabolic by-product formation. This method is in contrast to the traditional way of calculating ethanol fermentation efficiency, where the ratio between the ethanol produced and the sugar consumed is expressed as a percentage of the theoretical conversion yield. Comparison between the two methods, at industrial scale and in sensitivity studies, showed that the indirect method was more robust and gave slightly higher fermentation efficiency values, although fermentation efficiency of the industrial process was found to be low (~75%). The traditional calculation method is simpler than the indirect method as it only requires a few chemical determinations in samples collected. However, a minor error in any measured parameter will have an important impact on the calculated efficiency. In contrast, the indirect method of calculation requires a greater number of determinations but is much more robust since an error in any parameter will only have a minor effect on the fermentation efficiency value. The application of the indirect calculation methodology in order to evaluate the real situation of the process and to reach an optimum fermentation yield for an industrial-scale ethanol production is recommended. Once a high fermentation yield has been reached the traditional method should be used to maintain the control of the process. Upon detection of lower yields in an optimized process the indirect method should be employed as it permits a more accurate diagnosis of causes of yield losses in order to correct the problem rapidly. The low fermentation efficiency obtained in this study shows an urgent need for industrial process optimization where the indirect calculation methodology will be an important tool to determine process losses. © 2016 The Society for Applied Microbiology.

La fermentation éthanolique. Les microorganismes Ethanol Fermentation. The Microorganisms

Directory of Open Access Journals (Sweden)

Ballerini D.

2006-11-01

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

Alcoholic fermentation under oenological conditions. Use of a combination of data analysis and neural networks to predict sluggish and stuck fermentations

Energy Technology Data Exchange (ETDEWEB)

Insa, G. [Inst. National de la Recherche Agronomique, Inst. des Produits de la Vigne, Lab. de Microbiologie et Technologie des Fermentations, 34 - Montpellier (France); Sablayrolles, J.M. [Inst. National de la Recherche Agronomique, Inst. des Produits de la Vigne, Lab. de Microbiologie et Technologie des Fermentations, 34 - Montpellier (France); Douzal, V. [Centre National du Machinisme Agricole du Genie Rural des Eaux et Forets, 92 - Antony (France)

1995-09-01

The possibility of predicting sluggish fermentations under oenological conditions was investigated by studying 117 musts of different French grape varieties using an automatic device for fermentation monitoring. The objective was to detect sluggish or stuck fermentations at the halfway point of fermentation. Seventy nine percent of fermentations were correctly predicted by combining data analysis and neural networks. (orig.)

On-line monitoring of food fermentation processes using electronic noses and electronic tongues: A review

International Nuclear Information System (INIS)

Peris, Miguel; Escuder-Gilabert, Laura

2013-01-01

Graphical abstract: -- Highlights: •This review paper deals with the applications of electronic noses and electronic tongues to the monitoring of fermentation processes. •Positive and negative aspects of the different approaches reviewed are analyzed. •Current and future endeavors in this field are also commented. -- Abstract: Fermentation processes are often sensitive to even slight changes of conditions that may result in unacceptable end-product quality. Thus, close follow-up of this type of processes is critical for detecting unfavorable deviations as early as possible in order to save downtime, materials and resources. Nevertheless the use of traditional analytical techniques is often hindered by the need for expensive instrumentation and experienced operators and complex sample preparation. In this sense, one of the most promising ways of developing rapid and relatively inexpensive methods for quality control in fermentation processes is the use of chemical multisensor systems. In this work we present an overview of the most important contributions dealing with the monitoring of fermentation processes using electronic noses and electronic tongues. After a brief description of the fundamentals of both types of devices, the different approaches are critically commented, their strengths and weaknesses being highlighted. Finally, future trends in this field are also mentioned in the last section of the article

On-line monitoring of food fermentation processes using electronic noses and electronic tongues: A review

Energy Technology Data Exchange (ETDEWEB)

Peris, Miguel, E-mail: mperist@qim.upv.es [Departamento de Química, Universidad Politécnica de Valencia, 46071 Valencia (Spain); Escuder-Gilabert, Laura [Departamento de Química Analítica, Universitat de Valencia, C/ Vicente Andrés Estellés s/n, E-46100 Burjasot, Valencia (Spain)

2013-12-04

Graphical abstract: -- Highlights: •This review paper deals with the applications of electronic noses and electronic tongues to the monitoring of fermentation processes. •Positive and negative aspects of the different approaches reviewed are analyzed. •Current and future endeavors in this field are also commented. -- Abstract: Fermentation processes are often sensitive to even slight changes of conditions that may result in unacceptable end-product quality. Thus, close follow-up of this type of processes is critical for detecting unfavorable deviations as early as possible in order to save downtime, materials and resources. Nevertheless the use of traditional analytical techniques is often hindered by the need for expensive instrumentation and experienced operators and complex sample preparation. In this sense, one of the most promising ways of developing rapid and relatively inexpensive methods for quality control in fermentation processes is the use of chemical multisensor systems. In this work we present an overview of the most important contributions dealing with the monitoring of fermentation processes using electronic noses and electronic tongues. After a brief description of the fundamentals of both types of devices, the different approaches are critically commented, their strengths and weaknesses being highlighted. Finally, future trends in this field are also mentioned in the last section of the article.

Discovery and History of Amino Acid Fermentation.

Science.gov (United States)

Hashimoto, Shin-Ichi

There has been a strong demand in Japan and East Asia for L-glutamic acid as a seasoning since monosodium glutamate was found to present umami taste in 1907. The discovery of glutamate fermentation by Corynebacterium glutamicum in 1956 enabled abundant and low-cost production of the amino acid, creating a large market. The discovery also prompted researchers to develop fermentative production processes for other L-amino acids, such as lysine. Currently, the amino acid fermentation industry is so huge that more than 5 million metric tons of amino acids are manufactured annually all over the world, and this number continues to grow. Research on amino acid fermentation fostered the notion and skills of metabolic engineering which has been applied for the production of other compounds from renewable resources. The discovery of glutamate fermentation has had revolutionary impacts on both the industry and science. In this chapter, the history and development of glutamate fermentation, including the very early stage of fermentation of other amino acids, are reviewed.

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.

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

Science.gov (United States)

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

2014-08-06

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

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.

Application of Baechu-Kimchi Powder and GABA-Producing Lactic Acid Bacteria for the Production of Functional Fermented Sausages

Science.gov (United States)

Choi, Ji Hun; Kang, Ki Moon

2017-01-01

This study was carried out to determine the physicochemical, microbiological, and quality characteristics of a new type of fermented sausage manufactured by incorporating Baechu-kimchi powder and gamma-aminobutyric acid (GABA)-producing lactic acid bacteria (LAB). The LAB count was at the maximum level by day nine of ripening in inoculated sausages, accompanied by a rapid decrease in the pH. The addition of kimchi powder decreased the lightness (L*) and increased the redness (a*) and, yellowness (b*) values, while also significantly increasing the hardness and chewiness of the sausage (p<0.05). Moreover, although the thiobarbituric acid reactive substances values increased in all samples during the study period, this increase was lower in the kimchi-treated samples, indicating a reduction in lipid oxidation. Overall, our results show that the addition of Baechu-kimchi powder to sausages reduced the off-flavor properties and improved the taste profile of the fermented sausage in sensory evaluations. The GABA content of all fermented sausages increased from 17.42-25.14 mg/kg on the third day of fermentation to 60.95-61.47 mg/kg on the thirtieth day. These results demonstrate that Baechu-kimchi powder and GABA-producing LAB could be functional materials in fermented sausage to improve quality characteristics. PMID:29725201

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.

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.

Direct determination of calcium, sodium and potassium in fermented milk products

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Kravić Snežana Ž.

2012-01-01

Full Text Available The aim of this study was the investigation of the possibilities of direct determination of calcium, sodium and potassium in the commercial and kombucha-based fermented milk products by flame photometry. Two procedures were used for sample preparation: simple dilution with water (direct method and extraction with mineral acid. Calcium, sodium and potassium levels determined after mentioned sample preparation methods were compared. The results showed that the differences between the values obtained for the different sample treatment were within the experimental error at the 95% confidence level. Compared to the method based on extraction with mineral acid, the direct method is efficient, faster, simpler, cheaper, and operates according to the principles of Green Chemistry. Consequently, the proposed method for the direct determination of calcium, sodium and potassium could be applied for the rapid routine analysis of the mineral content in the fermented dairy products. [Projekat Ministarstva nauke Republike Srbije, br. III 46009

fermentation

African Journals Online (AJOL)

user

2012-05-17

May 17, 2012 ... genes in glycolysis pathway, trehalose and steroid biosynthesis and heat shock proteins (HSP) in .... com) and prepared for microarray construction and analysis. .... a single time point of the late stage of VHG fermentation.

Effect of mixing during fermentation in yogurt manufacturing.

Science.gov (United States)

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

2008-12-01

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

Gas Fermentation-A Flexible Platform for Commercial Scale Production of Low-Carbon-Fuels and Chemicals from Waste and Renewable Feedstocks.

Science.gov (United States)

Liew, FungMin; Martin, Michael E; Tappel, Ryan C; Heijstra, Björn D; Mihalcea, Christophe; Köpke, Michael

2016-01-01

There is an immediate need to drastically reduce the emissions associated with global fossil fuel consumption in order to limit climate change. However, carbon-based materials, chemicals, and transportation fuels are predominantly made from fossil sources and currently there is no alternative source available to adequately displace them. Gas-fermenting microorganisms that fix carbon dioxide (CO2) and carbon monoxide (CO) can break this dependence as they are capable of converting gaseous carbon to fuels and chemicals. As such, the technology can utilize a wide range of feedstocks including gasified organic matter of any sort (e.g., municipal solid waste, industrial waste, biomass, and agricultural waste residues) or industrial off-gases (e.g., from steel mills or processing plants). Gas fermentation has matured to the point that large-scale production of ethanol from gas has been demonstrated by two companies. This review gives an overview of the gas fermentation process, focusing specifically on anaerobic acetogens. Applications of synthetic biology and coupling gas fermentation to additional processes are discussed in detail. Both of these strategies, demonstrated at bench-scale, have abundant potential to rapidly expand the commercial product spectrum of gas fermentation and further improve efficiencies and yields.

Comprehensive Secondary Metabolite Profiling Toward Delineating the Solid and Submerged-State Fermentation of Aspergillus oryzae KCCM 12698

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Su Y. Son

2018-05-01

Full Text Available Aspergillus oryzae has been commonly used to make koji, meju, and soy sauce in traditional food fermentation industries. However, the metabolic behaviors of A. oryzae during fermentation in various culture environments are largely uncharacterized. Thus, we performed time resolved (0, 4, 8, 12, 16 day secondary metabolite profiling for A. oryzae KCCM 12698 cultivated on malt extract agar and broth (MEA and MEB under solid-state fermentation (SSF and submerged fermentation (SmF conditions using the ultrahigh performance liquid chromatography-linear trap quadrupole-ion trap-mass spectrometry (UHPLC-LTQ-IT-MS/MS followed by multivariate analyses. We observed the relatively higher proportions of coumarins and oxylipins in SSF, whereas the terpenoids were abundant in SmF. Moreover, we investigated the antimicrobial efficacy of metabolites that were extracted from SSF and SmF. The SSF extracts showed higher antimicrobial activities as compared to SmF, with higher production rates of bioactive secondary metabolites viz., ketone-citreoisocoumarin, pentahydroxy-anthraquinone, hexylitaconic acid, oxylipins, and saturated fatty acids. The current study provides the underpinnings of a metabolomic framework regarding the growth and bioactive compound production for A. oryzae under the primarily employed industrial cultivation states. Furthermore, the study holds the potentials for rapid screening and MS-characterization of metabolites helpful in determining the consumer safety implications of fermented foods involving Koji mold.

Vinegar rice (Oryza sativa L.) produced by a submerged fermentation process from alcoholic fermented rice

OpenAIRE

Spinosa,Wilma Aparecida; Santos Júnior,Vitório dos; Galvan,Diego; Fiorio,Jhonatan Luiz; Gomez,Raul Jorge Hernan Castro

2015-01-01

Considering the limited availability of technology for the production of rice vinegar and also due to the potential consumer product market, this study aimed to use alcoholic fermented rice (rice wine (Oryza sativa L.)) for vinegar production. An alcoholic solution with 6.28% (w/v) ethanol was oxidized by a submerged fermentation process to produce vinegar. The process of acetic acid fermentation occurred at 30 ± 0.3°C in a FRINGS® Acetator (Germany) for the production of vineg...

Alcoholic fermentation of stored sweet potatoes

Energy Technology Data Exchange (ETDEWEB)

Yutaka, Y; One, H

1958-01-01

Sweet potatoes were ground and stored in a ground hold. The stored sweet potatoes gave about 90% fermentation efficiency by the koji process. A lower fermentation efficiency by the amylo process was improved by adding 20 to 30 mg/100 ml of organic N. Inorganic N has no effect in improving the fermentation efficiency of the stored sweet potatoes by the amylo process.

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

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Huayi Suo

2015-11-01

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

Effect of Fermentation Conditions and Plucking Standards of Tea Leaves on the Chemical Components and Sensory Quality of Fermented Juice

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Ping Tang

2018-01-01

Full Text Available The effects of fermentation conditions (temperature, time, and pH and plucking standards (one leaf and a bud to four leaves and a bud on the chemical components and sensory quality of the fermented juices processed from crushed fresh tea leaves were investigated. The results showed that optimum fermentation conditions that resulted in fermented juices of the best sensory quality and the highest content of TFs were a temperature of 35°C, time duration of 75 min, and pH 5.1. The fermented juices processed from new shoots with three leaves and a bud or four leaves and a bud afforded high overall acceptability and TF concentration. These differences arise because tea leaves with different plucking standards have different catechin content and enzyme activities. Fermented tea juice possessed higher concentrations of chemical components such as soluble solids, amino acids, and TFs and exhibited better sensory quality as compared to black tea infusion. The TF concentrations decreased as the pH of the fermenting juice increased, and the fermented juice showed the best overall acceptability. These results provide essential information for the improvement of the processing of black tea beverage by suggesting fermentation of fresh tea leaves as a better alternative to their infusion.

A Model of the Effect of the Microbial Biomass on the Isotherm of the Fermenting Solids in Solid-State Fermentation

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Barbara Celuppi Marques

2006-01-01

Full Text Available We compare isotherms for soybeans and soybeans fermented with Rhizopus oryzae, showing that in solid-state fermentation the biomass affects the isotherm of the fermenting solids. Equations are developed to calculate, for a given overall water content of the fermenting solids, the water contents of the biomass and residual substrate, as well as the water activity. A case study, undertaken using a mathematical model of a well-mixed bioreactor, shows that if water additions are made on the basis of the assumption that fermenting solids have the same isotherm as the substrate itself, poor growth can result since the added water does not maintain the water activity at levels favorable for growth. We conclude that the effect of the microbial biomass on the isotherm of the fermenting solids must be taken into account in mathematical models of solid-state fermentation bioreactors.

Development of a quantitative PCR assay for rapid detection of Lactobacillus plantarum and Lactobacillus fermentum in cocoa bean fermentation.

Science.gov (United States)

Schwendimann, Livia; Kauf, Peter; Fieseler, Lars; Gantenbein-Demarchi, Corinne; Miescher Schwenninger, Susanne

2015-08-01

To monitor dominant species of lactic acid bacteria during cocoa bean fermentation, i.e. Lactobacillus plantarum and Lactobacillus fermentum, a fast and reliable culture-independent qPCR assay was developed. A modified DNA isolation procedure using a commercial kit followed by two species-specific qPCR assays resulted in 100% sensitivity for L. plantarum and L. fermentum. Kruskal-Wallis and post-hoc analyses of data obtained from experiments with cocoa beans that were artificially spiked with decimal concentrations of L. plantarum and L. fermentum strains allowed the calculation of a regression line suitable for the estimation of both species with a detection limit of 3 to 4 Log cells/g cocoa beans. This process was successfully tested for efficacy through the analyses of samples from laboratory-scale cocoa bean fermentations with both the qPCR assay and a culture-dependent method which resulted in comparable results. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of acetic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

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Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

2014-09-01

An integrated citric acid-methane fermentation process was proposed to solve the problem of extraction wastewater in citric acid fermentation process. Extraction wastewater was treated by anaerobic digestion and then recycled for the next batch of citric acid fermentation to eliminate wastewater discharge and reduce water resource consumption. Acetic acid as an intermediate product of methane fermentation was present in anaerobic digestion effluent. In this study, the effect of acetic acid on citric acid fermentation was investigated and results showed that lower concentration of acetic acid could promote Aspergillus niger growth and citric acid production. 5-Cyano-2,3-ditolyl tetrazolium chloride (CTC) staining was used to quantify the activity of A. niger cells, and the results suggested that when acetic acid concentration was above 8 mM at initial pH 4.5, the morphology of A. niger became uneven and the part of the cells' activity was significantly reduced, thereby resulting in deceasing of citric acid production. Effects of acetic acid on citric acid fermentation, as influenced by initial pH and cell number in inocula, were also examined. The result indicated that inhibition by acetic acid increased as initial pH declined and was rarely influenced by cell number in inocula.

Simultaneous saccharification and fermentation (SSF) using cellobiose fermenting yeast Brettanomyces custersii

Science.gov (United States)

Spindler, Diane D.; Grohmann, Karel; Wyman, Charles E.

1992-01-01

A process for producing ethanol from plant biomass includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the yeast Brettanomyces custersii (CBS 5512), which has the ability to ferment both cellobiose and glucose to ethanol, is then selected and isolated. The substrate is inoculated with this yeast, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol.

RAPD-PCR characterization of lactobacilli isolated from artisanal meat plants and traditional fermented sausages of Veneto region (Italy).

Science.gov (United States)

Andrighetto, C; Zampese, L; Lombardi, A

2001-07-01

The study was carried out to evaluate the use of randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) as a method for the identification of lactobacilli isolated from meat products. RAPD-PCR with primers M13 and D8635 was applied to the identification and intraspecific differentiation of 53 lactobacilli isolates originating from traditional fermented sausages and artisanal meat plants of the Veneto region (Italy). Most of the isolates were assigned to the species Lactobacillus sakei and Lact. curvatus; differentiation of groups of strains within the species was also possible. RAPD-PCR could be applied to the identification of lactobacilli species most commonly found in meat products. The method, which is easy and rapid to perform, could be useful for the study of the lactobacilli populations present in fermented sausages, and could help in the selection of candidate strains to use as starter cultures in meat fermentation.

Fermentation of irradiated sugarcane must

International Nuclear Information System (INIS)

Alcarde, Andre Ricardo; Horii, Jorge; Walder, Julio Marcos Melges

2003-01-01

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

Fermentation reactions of Erysipelothrix rhusiopathiae.

Science.gov (United States)

WHITE, T G; SHUMAN, R D

1961-10-01

White, Thomas G. (U. S. Department of Agriculture, Ames, Iowa), and Richard D. Shuman. Fermentation reactions of Erysipelothrix rhusiopathiae. J. Bacteriol. 82:595-599. 1961.-A study was made to determine the effect of four different basal media, to which fermentable carbon compounds had been added, upon 22 selected strains of Erysipelothrix rhusiopathiae (insidiosa). Acid production was measured by (i) chemical indicator, (ii) change in pH, and (iii) production of titrable acidity. At least two determinations, usually four, were made for each test on each strain. The fermentation pattern varied according to the medium, the indicator, and the method of measuring acid production. Andrade's base plus serum was the most dependable medium because it permitted the least variation in the total number of different patterns. Of the three methods used to measure acid production, the chemical indicator gave the most valid and reproducible results. The within-strain variation was not extreme and most strains persisted in a given fermentation pattern under like conditions of growth and acid production. Results of the study indicated that, regardless of the medium and indicator routinely used, one should be familiar with the fermentation pattern of known strains of the erysipelas organism.

Fermented dairy products: knowledge and consumption.

Science.gov (United States)

Hekmat, Sharareh; Koba, Lesia

2006-01-01

Much has been published on the nutritional and health benefits of fermented dairy products, especially those containing probiotic microorganisms. However, consumers may not be familiar with the term "fermented dairy products," and therefore may not take full advantage of them. University students' knowledge and consumption patterns of fermented dairy products were assessed. University students (n=223) completed a survey consisting of a section on demographics and another on knowledge and consumption patterns. The majority of respondents (62%) were not familiar with the term "fermented dairy products." Most respondents consumed yogourt a few times a week (40%) or a few times a month (30%). Almost all respondents (92%) were unable to identify the difference between regular and probiotic yogourt. Most respondents (93%) had not heard of acidophilus milk, but the majority (65%) would be willing to try it. Most respondents were unsure whether sour cream (65%), yogourt beverages (74%), and cheddar cheese (61%) were fermented dairy products. Sixty percent of respondents never consumed yogourt drinks. Education is needed about fermented dairy products, especially probiotics, and their nutritional and health benefits. Such education may increase their acceptability and consumption.

Comparison of microbial fermentation of high- and low-forage diets in Rusitec, single-flow continuous-culture fermenters and sheep rumen.

Science.gov (United States)

Carro, M D; Ranilla, M J; Martín-García, A I; Molina-Alcaide, E

2009-04-01

Eight Rusitec and eight single-flow continuous-culture fermenters (SFCCF) were used to compare the ruminal fermentation of two diets composed of alfalfa hay and concentrate in proportions of 80 : 20 (F80) and 20 : 80 (F20). Results were validated with those obtained previously in sheep fed the same diets. Rusitec fermenters were fed once daily and SFCCF twice, but liquid dilution rates were similar in both types of fermenters. Mean values of pH over the 12 h postfeeding were higher (P 0.05) were found in any in vitro system. A more precise control of pH in both types of fermenters and a reduction of concentrate retention time in Rusitec could probably improve the simulation of in vivo fermentation.

Biohydrogen production from combined dark-photo fermentation under a high ammonia content in the dark fermentation effluent

Energy Technology Data Exchange (ETDEWEB)

Chen, Chun-Yen [National Cheng Kung Univ., Tainan, Taiwan (China). Dept. of Chemical Engineering; National Cheng Kung Univ., Tainan, Taiwan (China). Sustainable Environment Research Center; Lo, Yung-Chung; Yeh, Kuei-Ling [National Cheng Kung Univ., Tainan, Taiwan (China). Dept. of Chemical Engineering; Chang, Jo-Shu [National Cheng Kung Univ., Tainan, Taiwan (China). Dept. of Chemical Engineering; National Cheng Kung Univ., Tainan, Taiwan (China). Sustainable Environment Research Center; National Cheng Kung Univ., Tainan, Taiwan (China). Microalgae Biotechnology and Bioengineering Lab.

2010-07-01

Integrated dark and photo (two-stage) fermentation was employed to enhance the performance of H{sub 2} production. First, the continuous dark fermentation using indigenous Clostridium butyricum CGS5 was carried out at 12 h HRT and fed with sucrose at a concentration of 18750 mg/l. The overall H{sub 2} production rate and H{sub 2} yield were fairly stable with a mean value of 87.5 ml/l/h and 1.015 mol H{sub 2}/mol sucrose, respectively. In addition, a relatively high ammonia nitrogen content (574 mg/l) in the dark fermentation effluent was observed. The soluble metabolites from dark fermentation, consisting mainly of butyric, lactic and acetic acids, were directly used as the influent of continuous photo-H{sub 2} production process inoculated with Rhodopseudomonas palutris WP 3-5 under the condition of 35oC, 10000 lux irradiation, pH 7.0 and 48 h HRT. The maximum overall hydrogen production rate from photo fermentation was 16.4 ml H{sub 2}/l/h, and the utilization of the soluble metabolites could reach 90%. The maximum H{sub 2} yield dramatically increased from 1.015 mol H{sub 2}/mol sucrose (in dark fermentation only) to 6.04 mol H{sub 2}/mol sucrose in the combined dark and photo fermentation. Surprisingly, the operation strategy applied in this work was able to attain an average NH{sub 3}-N removal efficiency of 92%, implying that our photo-H{sub 2} production system has a higher NH{sub 3}-N tolerance, demonstrating its high applicability in an integrated dark-photo fermentation system. (orig.)

Quantitative measurement of vitamin K2 (menaquinones) in various fermented dairy products using a reliable high-performance liquid chromatography method.

Science.gov (United States)

Manoury, E; Jourdon, K; Boyaval, P; Fourcassié, P

2013-03-01

We evaluated menaquinone contents in a large set of 62 fermented dairy products samples by using a new liquid chromatography method for accurate quantification of lipo-soluble vitamin K(2), including distribution of individual menaquinones. The method used a simple and rapid purification step to remove matrix components in various fermented dairy products 3 times faster than a reference preparation step. Moreover, the chromatography elution time was significantly shortened and resolution and efficiency were optimized. We observed wide diversity of vitamin K(2) contents in the set of fermented dairy products, from undetectable to 1,100 ng/g of product, and a remarkable diversity of menaquinone forms among products. These observations relate to the main microorganism species currently in the different fermented product technologies. The major form in this large set of fermented dairy products was menaquinone (MK)-9, and contents of MK-9 and MK-8 forms were correlated, that of MK-9 being around 4 times that of MK-8, suggesting that microorganisms able to produce MK-9 also produce MK-8. This was not the case for the other menaquinones, which were produced independently of each other. Finally, no obvious link was established between MK-9 content and fat content or pH of the fermented dairy products. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

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

Science.gov (United States)

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.

Improving wood hydrolyzate fermentation by using schizosaccharomycetes

Energy Technology Data Exchange (ETDEWEB)

Kalyuzhnyi, M Ya; Ustinova, V I; Petrushko, G I

1967-01-01

The development of Schizosaccharomycetes (I) in wood hydrolyzates is not observed when fermentation is carried out by the convetional batch process, evidently because of the highly inhibitory action of the medium. More recently, with the introduction of continuous fermentation of wood and other hydrolyzates, the occurrence of I has been frequently reported, and in some hydrolysis plants, I became predominant, eliminating the budding yeast strains. The phenomenon can be attributed to higher temperatures employed in continuous fermentation, and to a more favorable medium, as the hydrolyzate is diluted with spent fermentation liquor (the flow of fresh medium constitutes about 20% of the fermentation-vat volume). The I cells, when grown under favorable conditions, have a high fermenting power, adapt easily to the fermentation of galactose, and give higher yields of ethanol than the budding yeast. As observed at plants using I, however, the cells are sensitive to variations in the fermentation process, and are inactivated upon storage. This is usually attributed to their inability to store polysaccharides, and especially glycogen. An experimental study undertaken to determine conditions under which reserve polysaccharides accumulate in I cells showed that the important factor is the quality of the medium in which the cells are grown and the conditions of storage. In media enriched with spent fermentaion liquor or with cell autolyzate and purified from toxic components, considerable amounts of glycogen accumulate in the cells.

Enhanced substrate conversion effiency of fermentation processes

OpenAIRE

Sanders, J.P.M.; Weusthuis, R.A.; Mooibroek, H.

2008-01-01

The present invention relates to the field of fermentation technology. In particular the invention relates to fermentation processes for the production of a first and a second fermentation product by a single production organism wherein the first product is in a more reduced state than the substrate and the second fermentation product is in a more oxidised state than the substrate yet in a less oxidised state than the final oxidation product CO2, such that the concurrent synthesis of the firs...

Genomics of Probiotic Bacteria

Science.gov (United States)

O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

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

Directory of Open Access Journals (Sweden)

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.

Dietary fiber content influences soluble carbohydrate levels in ruminal fluids.

Science.gov (United States)

Pinder, R S; Patterson, J A; O'Bryan, C A; Crandall, P G; Ricke, S C

2012-01-01

The soluble carbohydrate concentration of ruminal fluid, as affected by dietary forage content (DFC) and/or ruminally undegradable intake protein content (UIPC), was determined. Four ruminally cannulated steers, in a 4 × 4 Latin square design, were offered diets containing high (75 % of DM) or low (25 % of DM) DFC and high (6 % of DM) or low (5 % of DM) UIPC, in a 2 × 2 factorial arrangement. Zinc-treated SBM was the primary UIP source. Soluble hexose concentration (145.1 μM) in ruminal fluid (RF) of steers fed low DFC diets exhibited a higher trend (P = 0.08) than that (124.5 μM) of steers fed high DFC diets. UIPC did not modulate (P = 0.54) ruminal soluble hexose concentrations. Regardless of diet, soluble hexose concentration declined immediately after feeding and did not rise until 3 h after feeding (P ruminal fluid could not be determined. However, unsubstituted xylose and arabinose were excluded. These data indicate that: (i) soluble carbohydrate concentrations remain in ruminal fluid during digestion and fermentation; (ii) slight diurnal changes began after feeding; (iii) DFC influences the soluble carbohydrate concentration in RF; and (iv) UIPC of these diets does not affect the soluble carbohydrate concentration of RF.

FERMENTED MILK AS A FUNCTIONAL FOOD

Directory of Open Access Journals (Sweden)

Irena Rogelj

2000-06-01

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

Xylose fermentation to ethanol. A review

Energy Technology Data Exchange (ETDEWEB)

McMillan, J D

1993-01-01

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

Enhanced substrate conversion efficiency of fermentation processes

NARCIS (Netherlands)

Sanders, J.P.M.; Weusthuis, R.A.; Mooibroek, H.

2006-01-01

The present invention relates to the field of fermentation technology. In particular the invention relates to fermentation processes for the production of a first and a second fermentation product by a single production organism wherein the first product is in a more reduced state than the substrate

Enhanced substrate conversion effiency of fermentation processes

NARCIS (Netherlands)

Sanders, J.P.M.; Weusthuis, R.A.; Mooibroek, H.

2008-01-01

The present invention relates to the field of fermentation technology. In particular the invention relates to fermentation processes for the production of a first and a second fermentation product by a single production organism wherein the first product is in a more reduced state than the substrate

Production of tea vinegar by batch and semicontinuous fermentation

OpenAIRE

Kaur, Pardeep; Kocher, G. S.; Phutela, R. P.

2010-01-01

The fermented tea vinegar combines the beneficial properties of tea and vinegar. The complete fermentation takes 4 to 5 weeks in a batch culture and thus can be shortened by semi continuous/ continuous fermentation using immobilized bacterial cells. In the present study, alcoholic fermentation of 1.0 and 1.5% tea infusions using Saccharomyces cerevisae G was carried out that resulted in 84.3 and 84.8% fermentation efficiency (FE) respectively. The batch vinegar fermentation of these wines wit...

Effect of fermented Banana peel on Broiler Carcass

Directory of Open Access Journals (Sweden)

Koni TNI

2013-06-01

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

Hydrogen Production by Thermophilic Fermentation

NARCIS (Netherlands)

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

2012-01-01

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

Phenolic profile and fermentation patterns of different commercial gluten-free pasta during in vitro large intestine fermentation.

Science.gov (United States)

Rocchetti, Gabriele; Lucini, Luigi; Chiodelli, Giulia; Giuberti, Gianluca; Gallo, Antonio; Masoero, Francesco; Trevisan, Marco

2017-07-01

The fate of phenolic compounds, along with short-chain fatty acids (SCFAs) production kinetics, was evaluated on six different commercial gluten-free (GF) pasta samples varying in ingredient compositions, focussing on the in vitro faecal fermentation after the gastrointestinal digestion. A general reduction of both total phenolics and reducing power was observed in all samples, together with a substantial change in phenolic profile over 24h of faecal fermentation, with differences among GF pasta samples. Flavonoids, hydroxycinnamics and lignans degraded over time, with a concurrent increase in low-molecular-weight phenolic acids (hydroxybenzoic acids), alkylphenols, hydroxybenzoketones and tyrosols. Interestingly, discriminant analysis also identified several alkyl derivatives of resorcinol as markers of the changes in phenolic profile during in vitro fermentation. Furthermore, degradation pathways of phenolics by intestinal microbiota have been proposed. Considering the total SCFAs and butyrate production during the in vitro fermentation, different fermentation kinetics were observed among GF pasta post-hydrolysis residues. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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.

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...

Drying characteristics and engineering properties of fermented ...

African Journals Online (AJOL)

STORAGESEVER

2009-03-06

Mar 6, 2009 ... fermented ground cassava. J. T. Nwabanne ... The drying characteristics of fermented ground local variety of ... effect of variety on the drying and engineering properties of fermented .... Figure 2 shows that the bulk density of each cultivar ... very close thermal conductivities as depicted in the shape of Figure ...

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.

Modeling Bacteriocin Resistance and Inactivation of Listeria innocua LMG 13568 by Lactobacillus sakei CTC 494 under Sausage Fermentation Conditions

Science.gov (United States)

Leroy, Frédéric; Lievens, Kristoff; De Vuyst, Luc

2005-01-01

In mixed cultures, bacteriocin production by the sausage isolate Lactobacillus sakei CTC 494 rapidly inactivated sensitive Listeria innocua LMG 13568 cells, even at low bacteriocin activity levels. A small fraction of the listerial population was bacteriocin resistant. However, sausage fermentation conditions inhibited regrowth of resistant cells. PMID:16269805

Fluidized Bed Reactor as Solid State Fermenter

Directory of Open Access Journals (Sweden)

Krishnaiah, K.

2005-01-01

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

Traditional fermented foods and beverages of Namibia

Directory of Open Access Journals (Sweden)

Jane Misihairabgwi

2017-09-01

Conclusion: Fermented foods and beverages play a major role in the diet, socioeconomic, and cultural activities of the Namibian population. Most are spontaneously fermented. Research is scarce and should be conducted on the microbiology, biochemistry, nutritional value, and safety of the fermented foods and beverages to ensure the health of the population.

Exploiting the potential of gas fermentation

DEFF Research Database (Denmark)

Redl, Stephanie Maria Anna; Diender, Martijn; Jensen, Torbjørn Ølshøj

2017-01-01

The use of gas fermentation for production of chemicals and fuels with lower environmental impact is a technology that is gaining increasing attention. Over 38 Gt of CO2 is annually being emitted from industrial processes, thereby contributing significantly to the concentration of greenhouse gases...... in the atmosphere. Together with the gasification of biomass and different waste streams, these gases have the potential for being utilized for production of chemicals through fermentation processes. Acetogens are among the most studied organisms capable of utilizing waste gases. Although engineering...... focus on the advantages of alternative fermentation scenarios, including thermophilic production strains, multi-stage fermentations, mixed cultures, as well as mixotrophy. Such processes have the potential to significantly broaden the product portfolio, increase the product concentrations and yields...

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.

The mitochondrial genome impacts respiration but not fermentation in interspecific Saccharomyces hybrids.

Directory of Open Access Journals (Sweden)

Warren Albertin

Full Text Available In eukaryotes, mitochondrial DNA (mtDNA has high rate of nucleotide substitution leading to different mitochondrial haplotypes called mitotypes. However, the impact of mitochondrial genetic variant on phenotypic variation has been poorly considered in microorganisms because mtDNA encodes very few genes compared to nuclear DNA, and also because mitochondrial inheritance is not uniparental. Here we propose original material to unravel mitotype impact on phenotype: we produced interspecific hybrids between S. cerevisiae and S. uvarum species, using fully homozygous diploid parental strains. For two different interspecific crosses involving different parental strains, we recovered 10 independent hybrids per cross, and allowed mtDNA fixation after around 80 generations. We developed PCR-based markers for the rapid discrimination of S. cerevisiae and S. uvarum mitochondrial DNA. For both crosses, we were able to isolate fully isogenic hybrids at the nuclear level, yet possessing either S. cerevisiae mtDNA (Sc-mtDNA or S. uvarum mtDNA (Su-mtDNA. Under fermentative conditions, the mitotype has no phenotypic impact on fermentation kinetics and products, which was expected since mtDNA are not necessary for fermentative metabolism. Alternatively, under respiratory conditions, hybrids with Sc-mtDNA have higher population growth performance, associated with higher respiratory rate. Indeed, far from the hypothesis that mtDNA variation is neutral, our work shows that mitochondrial polymorphism can have a strong impact on fitness components and hence on the evolutionary fate of the yeast populations. We hypothesize that under fermentative conditions, hybrids may fix stochastically one or the other mt-DNA, while respiratory environments may increase the probability to fix Sc-mtDNA.

Novel Method of Lactic Acid Production by Electrodialysis Fermentation

OpenAIRE

Hongo, Motoyoshi; Nomura, Yoshiyuki; Iwahara, Masayoshi

1986-01-01

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

27 CFR 24.176 - Crushing and fermentation.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Crushing and fermentation..., DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Wine § 24.176 Crushing and fermentation. (a) Natural... fermentation but the density of the juice may not be reduced below 22 degrees Brix. However, if the juice is...

Biochemical Characteristics and Viability of Probiotic and Yogurt Bacteria in Yogurt during the Fermentation and Refrigerated Storage

Directory of Open Access Journals (Sweden)

F Sarvari

2014-09-01

Full Text Available This research aimed to investigate the viability of probiotic bacteria (Lactobacillus acidophilus LA-5 and Bifidobacterium lactis BB-12 and yogurt bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus in yogurt during the fermentation, immediately after fermentation and during refrigerated storage (21 d, 4˚C. Also the biochemical characteristics of milk as affected by the commercial 4-strain mixed starter culture were investigated. Storage time affected the viability of all bacterial species. The concentration of lactic acid during the fermentation increased in parallel with the titrable acidity, and the concentration of acetic acid was proportional to the viability of Bifidobacterium lactis. The acetaldehyde level was decreased in the yogurt from day 0 up to the end of the storage. Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus were multiplied considerably during the fermentation. Streptococcus thermophilus could maintain its viability to the highest level, but Lactobacillus delbrueckii ssp. bulgaricus lost its viability rapidly during the cold storage compared to Streptococcus thermophilus. The multiplication and viability of probiotic bacteria were also influenced by the associative strains and species of yogurt organisms. Bifidobacteria counts were satisfactory. The loss of viability for bifidobacteria was gradual and steady during the storage, and they showed good stability during the storage as compared to Lactobacillus acidophilus.

Moisture content during extrusion of oats impacts the initial fermentation metabolites and probiotic bacteria during extended fermentation by human fecal microbiota.

Science.gov (United States)

Brahma, Sandrayee; Weier, Steven A; Rose, Devin J

2017-07-01

Extrusion exposes flour components to high pressure and shear during processing, which may affect the dietary fiber fermentability by human fecal microbiota. The objective of this study was to determine the effect of flour moisture content during extrusion on in vitro fermentation properties of whole grain oats. Extrudates were processed at three moisture levels (15%, 18%, and 21%) at fixed screw speed (300rpm) and temperature (130°C). The extrudates were then subjected to in vitro digestion and fermentation. Extrusion moisture significantly affected water-extractable β-glucan (WE-BG) in the extrudates, with samples processed at 15% moisture (lowest) and 21% moisture (highest) having the highest concentration of WE-BG. After the first 8h of fermentation, more WE-BG remained in fermentation media in samples processed at 15% moisture compared with the other conditions. Also, extrusion moisture significantly affected the production of acetate, butyrate, and total SCFA by the microbiota during the first 8h of fermentation. Microbiota grown on extrudates processed at 18% moisture had the highest production of acetate and total SCFA, whereas bacteria grown on extrudates processed at 15% and 18% moisture had the highest butyrate production. After 24h of fermentation, samples processed at 15% moisture supported lower Bifidobacterium counts than those produced at other conditions, but had among the highest Lactobacillus counts. Thus, moisture content during extrusion significantly affects production of fermentation metabolites by the gut microbiota during the initial stages of fermentation, while also affecting probiotic bacteria counts during extended fermentation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of submerged and anaerobic fermentations on cassava flour ...

African Journals Online (AJOL)

Cassava tubers for processing into cassava flour, Lafun a Nigerian locally fermented product was subjected to two different types of fermentations: submerged and anaerobic fermentation for 72 h. Physicochemical changes that occurred during fermentation and their influence on the functional, rheological and sensory ...

Microbial diversity and their roles in the vinegar fermentation process.

Science.gov (United States)

Li, Sha; Li, Pan; Feng, Feng; Luo, Li-Xin

2015-06-01

Vinegar is one of the oldest acetic acid-diluted solution products in the world. It is produced from any fermentable sugary substrate by various fermentation methods. The final vinegar products possess unique functions, which are endowed with many kinds of compounds formed in the fermentation process. The quality of vinegar is determined by many factors, especially by the raw materials and microbial diversity involved in vinegar fermentation. Given that metabolic products from the fermenting strains are directly related to the quality of the final products of vinegar, the microbial diversity and features of the dominant strains involved in different fermentation stages should be analyzed to improve the strains and stabilize fermentation. Moreover, although numerous microbiological studies have been conducted to examine the process of vinegar fermentation, knowledge about microbial diversity and their roles involved in fermentation is still fragmentary and not systematic enough. Therefore, in this review, the dominant microorganism species involved in the stages of alcoholic fermentation and acetic acid fermentation of dissimilar vinegars were summarized. We also summarized various physicochemical properties and crucial compounds in disparate types of vinegar. Furthermore, the merits and drawbacks of vital fermentation methods were generalized. Finally, we described in detail the relationships among microbial diversity, raw materials, fermentation methods, physicochemical properties, compounds, functionality, and final quality of vinegar. The integration of this information can provide us a detailed map about the microbial diversity and function involved in vinegar fermentation.

Production of lactic acid from hemicellulose extracts by Bacillus coagulans MXL-9.

Science.gov (United States)

Walton, Sara L; Bischoff, Kenneth M; van Heiningen, Adriaan R P; van Walsum, G Peter

2010-08-01

Bacillus coagulans MXL-9 was found capable of growing on pre-pulping hemicellulose extracts, utilizing all of the principle monosugars found in woody biomass. This organism is a moderate thermophile isolated from compost for its pentose-utilizing capabilities. It was found to have high tolerance for inhibitors such as acetic acid and sodium, which are present in pre-pulping hemicellulose extracts. Fermentation of 20 g/l xylose in the presence of 30 g/l acetic acid required a longer lag phase but overall lactic acid yield was not diminished. Similarly, fermentation of xylose in the presence of 20 g/l sodium increased the lag time but did not affect overall product yield, though 30 g/l sodium proved completely inhibitory. Fermentation of hot water-extracted Siberian larch containing 45 g/l total monosaccharides, mainly galactose and arabinose, produced 33 g/l lactic acid in 60 h and completely consumed all sugars. Small amounts of co-products were formed, including acetic acid, formic acid, and ethanol. Hemicellulose extract formed during autohydrolysis of mixed hardwoods contained mainly xylose and was converted into lactic acid with a 94% yield. Green liquor-extracted hardwood hemicellulose containing 10 g/l acetic acid and 6 g/l sodium was also completely converted into lactic acid at a 72% yield. The Bacillus coagulans MXL-9 strain was found to be well suited to production of lactic acid from lignocellulosic biomass due to its compatibility with conditions favorable to industrial enzymes and its ability to withstand inhibitors while rapidly consuming all pentose and hexose sugars of interest at high product yields.

Effect of fermentation period on the organic acid and amino acid contents of Ogiri from castor oil bean seeds

Directory of Open Access Journals (Sweden)

Ojinnaka, M-T. C.

2013-01-01

.Conclusion, significance and impact of study: Sufficient organic acids were detected in the three Bacillus fermented castor oil bean samples. The production of organic acids is undoubtedly the determining factor on which the shelf life and the safety of the final product depend while the inhibition of pathogenic and spoilage flora is also dependent on a rapid and adequate formation of these organic acids. The results of amino acid analysis indicated a high concentration of all amino acids especially at 96 h of fermentation. Amino acids are known to play a major role in the taste and flavour development of foods Thus the flavour and aroma of ogiri may be due to the production of amino acids, especially glutamic acid during the fermentation process.

Energy consumption in fermentation processes

Energy Technology Data Exchange (ETDEWEB)

Bach, P

1984-01-01

The purpose of the present publication is to limit energy used to aerate the anaerobic fermentation processes. In yeast production the aeration process consumes the greatest part of the total energy required. A mathematical model, based on literature data, is presented for a yeast fermenter. the effect of various aeration and raw product strategies can be calculated. Simulation of yeast fermentation proves it to be independent of oxygen transport. However interaction between flow conditions and biological kinetics (glucose effect) is a limiting factor. With many feeding point the use of enegy for aeration (mixing) can be reduced to 1/3 of the present one.

ISOLATION AND IDENTIFICATION OF MICROORGANISMS DURING SPONTANEOUS FERMENTATION OF MAIZE [Isolasi dan Identifikasi Mikroorganisme pada Fermentasi Spontan Jagung

Directory of Open Access Journals (Sweden)

Rahmawati1,2

2013-06-01

Full Text Available Maize was traditionally the second most common staple food in Indonesia. Conversion to maize flour has been accomplished to improve its convenience. Traditionally, maize flour is produced by soaking the kernels in water followed by grinding. It was reported that final physicochemical characteristics of the maize flour were influenced by spontaneous fermentation which occurred during soaking. This research aimed to isolate and identify important microorganisms that grew during fermentation thus a standardized starter culture can be developed for a more controlled fermentation process. Soaking of maize grits was conducted in sterile water (grits:water=1:2, w/v in a closed container at room temperature (±28ºC for 72 hours. After 0, 4, 12, 24, 36, 48, 72 hours, water and maize grits were sampled and tested for the presence of mold, yeast, and lactic acid bacteria (LAB. Isolates obtained from the spontaneous fermentation were reinoculated into the appropriate media containing starch to observe their amylolytic activity. Individual isolate was then identified; mold by slide culture method, while yeast and LAB by biochemical rapid kits, i.e. API 20C AUX and API CH50, respectively. The number of each microorganism was plotted against time to obtain the growth curve of the microorganisms during spontaneous fermentation. The microorganisms were identified as Penicillium chrysogenum, P. citrinum, A. flavus, A. niger, Rhizopus stolonifer, R.oryzae, Fusarium oxysporum, Acremonium strictum, Candida famata, Kodamaea ohmeri, Candida krusei/incospicua, Lactobacillus plantarum 1a, Pediococcus pentosaceus, L. brevis 1, L. plantarum 1b, and L. paracasei ssp paracasei 3. Four molds and one yeast were amylolytic while none of the LAB was capable of starch hydrolysis. The growth curve suggested that the amylolitic mold and yeast grew to hydrolyze starch during the course of fermentation, while the LABs benefited from the hydrolyzed products and dominated the later

Monitoring of alcoholic fermentation using near infrared and mid infrared spectroscopies combined with electronic nose and electronic tongue

International Nuclear Information System (INIS)

Buratti, S.; Ballabio, D.; Giovanelli, G.; Dominguez, C.M. Zuluanga; Moles, A.; Benedetti, S.; Sinelli, N.

2011-01-01

Graphical abstract: Application of non destructive methods for the monitoring of red wine fermentation in correlation with the evolution of chemical parameters. Highlights: → We monitored time-related changes in red wine fermentation process. → NIR and MIR spectroscopies, electronic nose and tongue were applied. → Data were kinetically modelled to identify critical points during fermentation. → NIR, MIR electronic nose and tongue were able to follow the fermentation process. → The models agreed with the evolution of chemical parameters. - Abstract: Effective fermentation monitoring is a growing need due to the rapid pace of change in the wine industry, which calls for fast methods providing real time information in order to assure the quality of the final product. The objective of this work is to investigate the potential of non-destructive techniques associated with chemometric data analysis, to monitor time-related changes that occur during red wine fermentation. Eight micro-fermentation trials conducted in the Valtellina region (Northern Italy) during the 2009 vintage, were monitored by a FT-NIR and a FT-IR spectrometer and by an electronic nose and tongue. The spectroscopic technique was used to investigate molecular changes, while electronic nose and electronic tongue evaluated the evolution of the aroma and taste profile during the must-wine fermentation. Must-wine samples were also analysed by traditional chemical methods in order to determine sugars (glucose and fructose) consumption and alcohol (ethanol and glycerol) production. Principal Component Analysis was applied to spectral, electronic nose and electronic tongue data, as an exploratory tool, to uncover molecular, aroma and taste modifications during the fermentation process. Furthermore, the chemical data and the PC1 scores from spectral, electronic nose and electronic tongue data were modelled as a function of time to identify critical points during fermentation. The results showed that

Monitoring of alcoholic fermentation using near infrared and mid infrared spectroscopies combined with electronic nose and electronic tongue

Energy Technology Data Exchange (ETDEWEB)

Buratti, S., E-mail: susanna.buratti@unimi.it [Department of Food Science and Technology, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano (Italy); Ballabio, D. [Department of Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Giovanelli, G. [Department of Food Science and Technology, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano (Italy); Dominguez, C.M. Zuluanga [Instituto de Ciencia y Tecnologia de Alimentos, Universidad Nacional de Colombia, Ciudad Universitaria, Bogota (Colombia); Moles, A.; Benedetti, S.; Sinelli, N. [Department of Food Science and Technology, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano (Italy)

2011-07-04

Graphical abstract: Application of non destructive methods for the monitoring of red wine fermentation in correlation with the evolution of chemical parameters. Highlights: > We monitored time-related changes in red wine fermentation process. > NIR and MIR spectroscopies, electronic nose and tongue were applied. > Data were kinetically modelled to identify critical points during fermentation. > NIR, MIR electronic nose and tongue were able to follow the fermentation process. > The models agreed with the evolution of chemical parameters. - Abstract: Effective fermentation monitoring is a growing need due to the rapid pace of change in the wine industry, which calls for fast methods providing real time information in order to assure the quality of the final product. The objective of this work is to investigate the potential of non-destructive techniques associated with chemometric data analysis, to monitor time-related changes that occur during red wine fermentation. Eight micro-fermentation trials conducted in the Valtellina region (Northern Italy) during the 2009 vintage, were monitored by a FT-NIR and a FT-IR spectrometer and by an electronic nose and tongue. The spectroscopic technique was used to investigate molecular changes, while electronic nose and electronic tongue evaluated the evolution of the aroma and taste profile during the must-wine fermentation. Must-wine samples were also analysed by traditional chemical methods in order to determine sugars (glucose and fructose) consumption and alcohol (ethanol and glycerol) production. Principal Component Analysis was applied to spectral, electronic nose and electronic tongue data, as an exploratory tool, to uncover molecular, aroma and taste modifications during the fermentation process. Furthermore, the chemical data and the PC1 scores from spectral, electronic nose and electronic tongue data were modelled as a function of time to identify critical points during fermentation. The results showed that NIR and MIR

Lactic acid fermentation of cassava dough into agbelima.

Science.gov (United States)

Amoa-Awua, W K; Appoh, F E; Jakobsen, M

1996-08-01

The souring of cassava dough during fermentation into the fermented cassava meal, agbelima, was investigated. Four different types of traditional inocula were used to ferment the dough and increases in titrable acidity expressed as lactic acid from 0.31-0.38 to 0.78-0.91% (w/w) confirmed the fermentation to be a process of acidification. The microflora of all inocula and fermenting dough contained high counts of lactic acid bacteria, 10(8)-10(9) cfu/g in all inocula and 10(7)-10(8), 10(8)-10(9) and 10(9) cfu/g at 0, 24 and 48 h in all fermentations. Lactobacillus plantarum was the dominant species of lactic acid bacteria during all types of fermentation accounting for 51% of 171 representative isolates taken from various stages of fermentation. Other major lactic acid bacteria found were Lactobacillus brevis, 16%, Leuconostoc mesenteroides, 15% and some cocci including Streptococcus spp. whose numbers decreased with fermentation time. The lactic acid bacteria were responsible for the souring of agbelima through the production of lactic acid. All L. plantarum, L. brevis and L. mesenteroides isolates examined demonstrated linamarase as well as other enzymatic activities but did not possess tissue degrading enzymes like cellulase, pectin esterase and polygalacturonase. The aroma profile of agbelima did not vary with the type of inoculum used and in all samples the build-up of aroma compounds were dominated by a non-identified low molecular weight alcohol, 1-propanol, isoamyl alcohol, ethyl acetate, 3-methyl-1-butanol and acetoin. Substantial reductions occurred in the levels of cyanogenic compounds present in cassava during fermentation into agbelima and detoxification was enhanced by the use of inoculum.

Challenges in industrial fermentation technology research

DEFF Research Database (Denmark)

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

2014-01-01

Industrial fermentation processes are increasingly popular, and are considered an important technological asset for reducing our dependence on chemicals and products produced from fossil fuels. However, despite their increasing popularity, fermentation processes have not yet reached the same...... engineering challenges: scaling up and scaling down fermentation processes, the influence of morphology on broth rheology and mass transfer, and establishing novel sensors to measure and control insightful process parameters. The greatest emphasis is on the challenges posed by filamentous fungi, because...

Effect of fermentation and drying on cocoa polyphenols.

Science.gov (United States)

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

2015-11-18

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

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.

Experiments with Fungi Part 2: Fermentation.

Science.gov (United States)

Dale, Michele; Hetherington, Shane

1996-01-01

Gives details of three experiments with alcoholic fermentation by yeasts which yield carbon dioxide and ethanol. Lists procedures for making cider, vinegar, and fermentation gases. Provides some historical background and detailed equipment requirements. (DDR)

Continuous fermentation of carbohydrate-containing liquids to alcohol

Energy Technology Data Exchange (ETDEWEB)

Moldenhauer, O; Lechner, R

1955-08-25

Rate of alcohol fermentation depends mostly on the biological state of the yeast. The process described avoids retardation during the final fermentation phase by increasing the concentration of yeast as the fermentation proceeds. The method is especially suitable for dilute carbohydrate solutions. Thus, to a solution containing 4% carbohydrates, 66 g pressed yeast was added. This mash was passed continuously through several fermentation vessels. The temperature was adjusted to 29 to 35 degrees according to the type of yeast. Before entering the next vessel, another portion of pressed yeast (66 g/1 of mash) is added. The yeast is recovered from the fermented mash by means of a yeast separator.

Continuous fermentation of carbohydrate-containing liquids to alcohol

Energy Technology Data Exchange (ETDEWEB)

Moldenhauer, O; Lechner, R

1955-08-29

Rate of alcohol fermentation depends mostly on the biological state of the yeast. The process described avoids retardation during the final fermentation phase by increasing the concentration of yeast as the fermentation proceeds. The method is especially suitable for dilute carbohydrate solutions. Thus, to a solution containing 4% carbohydrates, 66 g pressed yeast was added. This mash was passed continuously through several fermentation vessels. The temperature was adjusted to 29 to 35/sup 0/ according to the type of yeast. Before entering the next vessel, another portion of pressed yeast (66 g/l of mash) is added. The yeast is recovered from the fermented mash by means of a yeast separator.

Effect of pH fermentation on production bioethanol from jackfruit seeds (Artocarpus heterophyllus) through separate fermentation hydrolysis method

Science.gov (United States)

Arif, A. R.; Natsir, H.; Rohani, H.; Karim, A.

2018-03-01

Bioethanol is one of the alternative energy sourced from natural products containing carbohydrates through hydrolysis and fermentation process. Jackfruit seeds is one of the feedstock that contain high carbohydrate content but less utilized. The aims of this study to determine the effect of pH hydrolysis in the process of production bioethanol from jackfruit seeds (Artocarpus heterophyllus) through separate fermentation hydrolysis (SHF) method. The hydrolysis process uses H2SO4 as a hydrolyzing agent. The fermentation process used Saccharomyces cereviceae as a fermentor with a variation of pH 2,3 4 and 5 for 70 hours. The results showed that glucose content of 75% and pH 3 was the optimum pH of fermentation with the content of bioethanol 57.94%. The fermentation stage has an important role in increasing the levels of glucose and bioethanol in linear. The content of glucose and bioethanol of jackfruit seeds showed a great potential for development as the feedstock in bioethanol production.

Single-cell analysis of S. cerevisiae growth recovery after a sublethal heat-stress applied during an alcoholic fermentation.

Science.gov (United States)

Tibayrenc, Pierre; Preziosi-Belloy, Laurence; Ghommidh, Charles

2011-06-01

Interest in bioethanol production has experienced a resurgence in the last few years. Poor temperature control in industrial fermentation tanks exposes the yeast cells used for this production to intermittent heat stress which impairs fermentation efficiency. Therefore, there is a need for yeast strains with improved tolerance, able to recover from such temperature variations. Accordingly, this paper reports the development of methods for the characterization of Saccharomyces cerevisiae growth recovery after a sublethal heat stress. Single-cell measurements were carried out in order to detect cell-to-cell variability. Alcoholic batch fermentations were performed on a defined medium in a 2 l instrumented bioreactor. A rapid temperature shift from 33 to 43 °C was applied when ethanol concentration reached 50 g l⁻¹. Samples were collected at different times after the temperature shift. Single cell growth capability, lag-time and initial growth rate were determined by monitoring the growth of a statistically significant number of cells after agar medium plating. The rapid temperature shift resulted in an immediate arrest of growth and triggered a progressive loss of cultivability from 100 to 0.0001% within 8 h. Heat-injured cells were able to recover their growth capability on agar medium after a lag phase. Lag-time was longer and more widely distributed as the time of heat exposure increased. Thus, lag-time distribution gives an insight into strain sensitivity to heat-stress, and could be helpful for the selection of yeast strains of technological interest.

Influence of trace elements mixture on bacterial diversity and fermentation characteristics of liquid diet fermented with probiotics under air-tight condition.

Directory of Open Access Journals (Sweden)

Yuyong He

Full Text Available Cu2+, Zn2+, Fe2+ and I- are often supplemented to the diet of suckling and early weaning piglets, but little information is available regarding the effects of different Cu2+, Zn2+, Fe2+ and I- mixtures on bacteria growth, diversity and fermentation characteristics of fermented liquid diet for piglets. Pyrosequencing was performed to investigate the effect of Cu2+, Zn2+, Fe2+ and I- mixtures on the diversity, growth and fermentation characteristics of bacteria in the liquid diet fermented with Bacillus subtilis and Enterococcus faecalis under air-tight condition. Results showed that the mixtures of Cu2+, Zn2+, Fe2+ and I- at different concentrations promoted Bacillus growth, increased bacterial diversity and lactic acid production and lowered pH to about 5. The importance of Cu2+, Zn2+, Fe2+ and I- is different for Bacillus growth with the order Zn2+> Fe2+>Cu2+> I- in a 21-d fermentation and Cu2+>I->Fe2+>Zn2+ in a 42-d fermentation. Cu2+, Zn2+, Fe2+ and I- is recommended at a level of 150, 60, 150 and 0.6 mg/kg respectively for the production of fermented liquid diet with Bacillus subtilis. The findings improve our understanding of the influence of trace elements on liquid diet fermentation with probiotics and support the proper use of trace elements in the production of fermented liquid diet for piglets.

Functional identification of an Arabidopsis snf4 ortholog by screening for heterologous multicopy suppressors of snf4 deficiency in yeast

DEFF Research Database (Denmark)

Kleinow, T.; Bhalerao, R.; Breuer, F.

2000-01-01

Yeast Snf4 is a prototype of activating gamma-subunits of conserved Snf1/AMPK-related protein kinases (SnRKs) controlling glucose and stress signaling in eukaryotes. The catalytic subunits of Arabidopsis SnRKs, AKIN10 and AKIN11, interact with Snf4 and suppress the snf1 and snf4 mutations in yeast....... By expression of an Arabidopsis cDNA library in yeast, heterologous multicopy snf4 suppressors were isolated. In addition to AKIN10 and AKIN11, the deficiency of yeast snf4 mutant to grown on non-fermentable carbon source was suppressed by Arabidopsis Myb30, CAAT-binding factor Hap3b, casein kinase I, zinc......-finger factors AZF2 and ZAT10, as well as orthologs of hexose/UDP-hexose transporters, calmodulin, SMC1-cohesin and Snf4. Here we describe the characterization of AtSNF4, a functional Arabidopsis Snf4 ortholog, that interacts with yeast Snf1 and specifically binds to the C-terminal regulatory domain...

The effect of lactic acid bacteria on cocoa bean fermentation.

Science.gov (United States)

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

2015-07-16

Cocoa beans (Theobroma cacao L.) are the raw material for chocolate production. Fermentation of cocoa pulp by microorganisms is crucial for developing chocolate flavor precursors. Yeasts conduct an alcoholic fermentation within the bean pulp that is essential for the production of good quality beans, giving typical chocolate characters. However, the roles of bacteria such as lactic acid bacteria and acetic acid bacteria in contributing to the quality of cocoa bean and chocolate are not fully understood. Using controlled laboratory fermentations, this study investigated the contribution of lactic acid bacteria to cocoa bean fermentation. Cocoa beans were fermented under conditions where the growth of lactic acid bacteria was restricted by the use of nisin and lysozyme. The resultant microbial ecology, chemistry and chocolate quality of beans from these fermentations were compared with those of indigenous (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii, Kluyveromyces marxianus and Saccharomyces cerevisiae, the lactic acid bacteria Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in control fermentations. In fermentations with the presence of nisin and lysozyme, the same species of yeasts and acetic acid bacteria grew but the growth of lactic acid bacteria was prevented or restricted. These beans underwent characteristic alcoholic fermentation where the utilization of sugars and the production of ethanol, organic acids and volatile compounds in the bean pulp and nibs were similar for beans fermented in the presence of lactic acid bacteria. Lactic acid was produced during both fermentations but more so when lactic acid bacteria grew. Beans fermented in the presence or absence of lactic acid bacteria were fully fermented, had similar shell weights and gave acceptable chocolates with no differences

Microbe-microbe interactions in mixed culture food fermentations

NARCIS (Netherlands)

Smid, E.J.; Lacroix, C.

2013-01-01

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

Fermentation of lignocellulosic hydrolysates: Inhibition and detoxification

Energy Technology Data Exchange (ETDEWEB)

Palmqvist, E.

1998-02-01

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

Effect of fermented Banana peel on Broiler Carcass

OpenAIRE

Koni TNI

2013-01-01

This experiment was conducted to examine effect of inclusion of fermented banana peel by Rhyzopus oligosporus in diets on slaughter weight, carcass weight and carcass percentage, weight and percentage abdominal fat of broiler. The experiment was done based on Completely Randomized Design with four treatments and four replications and each replication consisted of six chickens. The treatment were R0 = without banana peel fermented, R1 = 5% banana peel fermented, R2 = 10% banana peel fermented...

The economics of ethanol production by extractive fermentation

Energy Technology Data Exchange (ETDEWEB)

Daugulis, A J; Axford, D B; McLellan, P J [Queen' s Univ., Kingston, ON (Canada)

1991-04-01

Extractive fermentation is a processing strategy in which reaction and recovery occur simultaneously in a fermentation vessel through the use of a water-immiscible solvent which selectively removes an inhibitory product. An ethanol-extractive fermentation process has been developed, incorporating continuous operation and the ability to ferment concentrated feedstocks. A detailed economic assessment of this process is provided relative to current technology for an annual capacity of 100 million litres of ethanol. Extractive fermentation provides significant economic advantages for both grass roots and retrofitted plants. Total production costs are estimated at 45{cents}/l for a conventional plant and 29.4{cents}/l for a retrofitted plant. The main cost saving achievable by extractive fermentation is in energy, used for evaporation and drying, since the process uses significantly less water in its conversion of concentrated feedstocks. Producing anhydrous ethanol without distillation is also a prospect. 15 refs., 5 fig., 10 tabs.

(ajst) influence of fermentation and cowpea

African Journals Online (AJOL)

opiyo

Statgraphics (Graphics Software System, STCC, Inc. U.S.A). Comparisons .... 7 2. 0.473. 0.597. 1.056. 0.14. Co-fermentation. Fermented maize and cowpea blends showed varied effects ...... Oligosaccharides in eleven Legumes and their air-.

Real-Time Monitoring of Chemical Changes in Three Kinds of Fermented Milk Products during Fermentation Using Quantitative Difference Nuclear Magnetic Resonance Spectroscopy.

Science.gov (United States)

Lu, Yi; Ishikawa, Hiroto; Kwon, Yeondae; Hu, Fangyu; Miyakawa, Takuya; Tanokura, Masaru

2018-02-14

Fermented milk products are rising in popularity throughout the world as a result of their health benefits, including improving digestion, normalizing the function of the immune system, and aiding in weight management. This study applies an in situ quantitative nuclear magnetic resonance method to monitor chemical changes in three kinds of fermented milk products, Bulgarian yogurt, Caspian Sea yogurt, and kefir, during fermentation. As a result, the concentration changes in nine organic compounds, α/β-lactose, α/β-galactose, lactic acid, citrate, ethanol, lecithin, and creatine, were monitored in real time. This revealed three distinct metabolic processes in the three fermented milk products. Moreover, pH changes were also determined by variations in the chemical shift of citric acid during the fermentation processes. These results can be applied to estimate microbial metabolism in various flora and help guide the fermentation and storage of various fermented milk products to improve their quality, which may directly influence human health.

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.

Acetic acid bacteria in fermented foods and beverages.

Science.gov (United States)

De Roos, Jonas; De Vuyst, Luc

2018-02-01

Although acetic acid bacteria (AAB) are commonly found in spontaneous or backslopped fermented foods and beverages, rather limited knowledge about their occurrence and functional role in natural food fermentation ecosystems is available. Not only is their cultivation, isolation, and identification difficult, their cells are often present in a viable but not culturable state. Yet, they are promising starter cultures either to better control known food fermentation processes or to produce novel fermented foods and beverages. This review summarizes the most recent findings on the occurrence and functional role of AAB in natural food fermentation processes such as lambic beer, water kefir, kombucha, and cocoa. Copyright © 2017 Elsevier Ltd. All rights reserved.

Understanding Kombucha Tea Fermentation: A Review.

Science.gov (United States)

Villarreal-Soto, Silvia Alejandra; Beaufort, Sandra; Bouajila, Jalloul; Souchard, Jean-Pierre; Taillandier, Patricia

2018-03-01

Kombucha is a beverage of probable Manchurian origins obtained from fermented tea by a microbial consortium composed of several bacteria and yeasts. This mixed consortium forms a powerful symbiosis capable of inhibiting the growth of potentially contaminating bacteria. The fermentation process also leads to the formation of a polymeric cellulose pellicle due to the activity of certain strains of Acetobacter sp. The tea fermentation process by the microbial consortium was able to show an increase in certain biological activities which have been already studied; however, little information is available on the characterization of its active components and their evolution during fermentation. Studies have also reported that the use of infusions from other plants may be a promising alternative. Kombucha is a traditional fermented tea whose consumption has increased in the recent years due to its multiple functional properties such as anti-inflammatory potential and antioxidant activity. The microbiological composition of this beverage is quite complex and still more research is needed in order to fully understand its behavior. This study comprises the chemical and microbiological composition of the tea and the main factors that may affect its production. © 2018 Institute of Food Technologists®.

Interactions of meat-associated bacteriocin-producing Lactobacilli with Listeria innocua under stringent sausage fermentation conditions.

Science.gov (United States)

Leroy, Frédéric; Lievens, Kristoff; De Vuyst, Luc

2005-10-01

The kinetics of the antilisterial effect of meat-associated lactobacilli on Listeria innocua LMG 13568 were investigated during laboratory batch fermentations. During these fermentations, which were performed in a liquid meat simulation medium, a combination of process factors typical for European-style sausage fermentations was applied, such as a temperature of 20 degrees C and a representative pH and salting profile. Two bacteriocin-producing sausage isolates (Lactobacillus sakei CTC 494 and Lactobacillus curvatus LTH 1174), which have already proven efficacy in sausage trials, and one nonbacteriocinogenic, industrial strain (Lactobacillus sakei I), were evaluated. Staphylococcus carnosus 833 was included in the experiment because of its role in flavor and color development. When grown as a monoculture or upon cocultivation with L. sakei I and S. carnosus 833, L. innocua LMG 13568 developed slightly, despite the stress of low temperature, pH, lactic acid, salt, and nitrite. In contrast, when either of the bacteriocin producers was used, the L. innocua LMG 13568 population was rapidly inactivated with more than 3 log CFU ml(-1) after 2 days of fermentation. A bacteriocin-tolerant L. innocua LMG 13568 subpopulation (4 X 10(-4)) remained after bacteriocin inactivation. Thus, when the initial level of L. innocua LMG 13568 equaled 3 log CFU ml(-1), all cells were inactivated and no bacteriocin-tolerant cells were detected, even after 7 days of incubation. S. carnosus was not inactivated by the Lactobacillus bacteriocins and displayed slight growth.

Flavour Characters of Wines from Cool-Climate Grape Cultivars in Relation to Different Fermentation Approaches

DEFF Research Database (Denmark)

Liu, Jing

-climate grape cultivars have been grown. However there is little knowledge on the flavour properties and potential of Danish wines. The overall aim of this project was to investigate the sensory characters and chemical composition of wines from different cool-climate grape cultivars and co-fermentations...... caused by inadequate sulphite management, which resulted in accelerated aging, oxidation and/or spontaneous malolactic fermentation. These findings indicated that producers in Denmark should be more cautious in their use and management of sulphite in wine making. To develop a rapid methodology...... for evaluating sensory properties of wines, different variations of Napping and Flash Profile methods were tested using model wines. It turned out that conducting Napping with panel training on either the method (training on how to arrange samples on the sheet) or the product (familiarization with the sensory...

Effects of concentrate replacement by feed blocks on ruminal fermentation and microbial growth in goats and single-flow continuous-culture fermenters.

Science.gov (United States)

Molina-Alcaide, E; Pascual, M R; Cantalapiedra-Hijar, G; Morales-García, E Y; Martín-García, A I

2009-04-01

The effect of replacing concentrate with 2 different feed blocks (FB) on ruminal fermentation and microbial growth was evaluated in goats and in single-flow continuous-culture fermenters. Diets consisted of alfalfa hay plus concentrate and alfalfa hay plus concentrate with 1 of the 2 studied FB. Three trials were carried out with 6 rumen-fistulated Granadina goats and 3 incubation runs in 6 single-flow continuous-culture fermenters. Experimental treatments were assigned randomly within each run, with 2 repetitions for each diet. At the end of each in vivo trial, the rumen contents were obtained for inoculating the fermenters. For each incubation run, the fermenters were inoculated with ruminal fluid from goats fed the same diet supplied to the corresponding fermenter flask. The average pH values, total and individual VFA, and NH(3)-N concentrations, and acetate:propionate ratios in the rumen of goats were not affected (P >or= 0.10) by diet, whereas the microbial N flow (MNF) and efficiency were affected (P fermenters, the diet affected pH (Por= 0.05), and total (P=0.02), NH(3) (P=0.005), and non-NH(3) (P=0.02) N flows, whereas the efficiency of VFA production was not affected (P=0.75). The effect of diet on MNF and efficiency depended on the bacterial pellet used as a reference. An effect (Pfermenter contents and effluent were similar (P=0.05). Differences (Pfermentation variables and bacterial pellet compositions were found. Partial replacement of the concentrate with FB did not greatly compromise carbohydrate fermentation in unproductive goats. However, this was not the case for MNF and efficiency. Differences between the results obtained in vivo and in vitro indicate a need to identify conditions in fermenters that allow better simulation of fermentation, microbial growth, and bacterial pellet composition in vivo. Reduced feeding cost could be achieved with the inclusion of FB in the diets of unproductive goats without altering rumen fermentation.

Yeast Biodiversity from DOQ Priorat Uninoculated Fermentations.

Science.gov (United States)

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

2016-01-01

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

Fermentation capability of bulk milk under usual conditions

OpenAIRE

BOUŠKOVÁ, Lucie

2012-01-01

The evaluation of changes during fermentation of heat-modified milk in connection with different fermentation temperatures was main goal of this thesis. Titrable acidity, active acidity and growth dynamics of bacteria strains - Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus were observed during fermentation process.

Statistical Optimisation of Fermentation Conditions for Citric Acid ...

African Journals Online (AJOL)

This study investigated the optimisation of fermentation conditions during citric acid production via solid state fermentation (SSF) of pineapple peels using Aspergillus niger. A three-variable, three-level Box-Behnken design (BBD) comprising 17 experimental runs was used to develop a statistical model for the fermentation ...

Ethanol fermentation characteristics of recycled water by Saccharomyces cerevisiae in an integrated ethanol-methane fermentation process.

Science.gov (United States)

Yang, Xinchao; Wang, Ke; Wang, Huijun; Zhang, Jianhua; Mao, Zhonggui

2016-11-01

An process of integrated ethanol-methane fermentation with improved economics has been studied extensively in recent years, where the process water used for a subsequent fermentation of carbohydrate biomass is recycled. This paper presents a systematic study of the ethanol fermentation characteristics of recycled process water. Compared with tap water, fermentation time was shortened by 40% when mixed water was employed. However, while the maximal ethanol production rate increased from 1.07g/L/h to 2.01g/L/h, ethanol production was not enhanced. Cell number rose from 0.6×10(8) per mL in tap water to 1.6×10(8) per mL in mixed water but although biomass increased, cell morphology was not affected. Furthermore, the use of mixed water increased the glycerol yield but decreased that of acetic acid, and the final pH with mixed water was higher than when using tap water. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Lactic acid bacteria involved in cocoa beans fermentation from Ivory Coast: Species diversity and citrate lyase production.

Science.gov (United States)

Ouattara, Hadja D; Ouattara, Honoré G; Droux, Michel; Reverchon, Sylvie; Nasser, William; Niamke, Sébastien L

2017-09-01

Microbial fermentation is an indispensable process for high quality chocolate from cocoa bean raw material. lactic acid bacteria (LAB) are among the major microorganisms responsible for cocoa fermentation but their exact role remains to be elucidated. In this study, we analyzed the diversity of LAB in six cocoa producing regions of Ivory Coast. Ribosomal 16S gene sequence analysis showed that Lactobacillus plantarum and Leuconostoc mesenteroides are the dominant LAB species in these six regions. In addition, other species were identified as the minor microbial population, namely Lactobacillus curieae, Enterococcus faecium, Fructobacillus pseudoficulneus, Lactobacillus casei, Weissella paramesenteroides and Weissella cibaria. However, in each region, the LAB microbial population was composed of a restricted number of species (maximum 5 species), which varied between the different regions. LAB implication in the breakdown of citric acid was investigated as a fundamental property for a successful cocoa fermentation process. High citrate lyase producer strains were characterized by rapid citric acid consumption, as revealed by a 4-fold decrease in citric acid concentration in the growth medium within 12h, concomitant with an increase in acetic acid and lactic acid concentration. The production of citrate lyase was strongly dependent on environmental conditions, with optimum production at acidic pH (pHfermentation. This study reveals that one of the major roles of LAB in the cocoa fermentation process involves the breakdown of citric acid during the early stage of cocoa fermentation through the activity of citrate lyase. Copyright © 2017 Elsevier B.V. All rights reserved.

21 CFR 573.450 - Fermented ammoniated condensed whey.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Fermented ammoniated condensed whey. 573.450... ANIMALS Food Additive Listing § 573.450 Fermented ammoniated condensed whey. (a) Identity. The product is produced by the Lactobacillus bulgaricus fermentation of whey with the addition of ammonia. (b...

Does fermented milk possess antihypertensive effect in humans?

DEFF Research Database (Denmark)

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

2009-01-01

The putative antihypertensive effect of milk after fermentation by lactic bacteria has attracted attention over the past 20 years. Research on fermented milk and hypertension has mainly focused on the content of peptides with in-vitro angiotensin converting enzyme-inhibitor effect. However......, fermented milk products contain several proteins, peptides and minerals, all with possible different antihypertensive modes of actions. The burden of cardiovascular events in industrialized countries caused by hypertension is considerable. Diet modifications are one way to lower blood pressure......, and fermented milk could be a feasible way. In this review, interventional human studies of the possible antihypertensive effect of fermented milk are evaluated. The results are diverging, and the antihypertensive effect is still debatable. Additionally, present knowledge of bioavailability and in-vivo actions...

Modelling of the process yields of a whey fermentation

Energy Technology Data Exchange (ETDEWEB)

Blakebrough, N; Moresi, M

1981-09-01

The biomass yields (y) and COD reduction efficiencies (eta) of a whey fermentation by Kluyveromyces fragilis were studied in a 100-l fermenter at various stirrer speeds and lactose concentrations, and compared to those obtained in 10-l and 15-l fermenters at constant values of the oxygen transfer coefficient (ksub(L)a) and air velocity. The empirical models previously constructed by using the 15-l fermenter data could be used to predict the yields on the other scales by calculating for each run the 15-l fermenter which would provide the same oxygen transfer coefficient measured by the sulphite method on each fermenter under study. To make this model independent of stirrer speeds used in each generic fermenter, the effect of aeration and mixing was incorporated into an overall parameter (ksub(L)a) and the values of y and eta were correlated only with temperature, lactose level and ksub(L)a since these variables were approximately orthogonal.

Modelling of the process yields of a whey fermentation

Energy Technology Data Exchange (ETDEWEB)

Blakebrough, N; Moresi, M

1981-01-01

The biomass yields (y) and COD reduction efficiencies (eta) of a whey fermentation by Kluyveromyces fragilis were studied in a 100-l fermenter at various stirrer speeds and lactose concentrations, and compared to those obtained in 10-l and 15-l fermenters at constant values of the oxygen transfer coefficient (kla) and air velocity. The empirical models previously constructed by using the 15-l fermenter data could be used to predict the yields on the other scales by calculating for each run the 15-l fermenter which would provide the same oxygen transfer coefficient measured by the sulfite method on each fermenter under study. To make this model independent of stirrer speeds used in each generic fermenter, the effect of aeration and mixing was incorporated into an overall parameter (kla) and the values of y and eta were correlated only with temperature, lactose level and kla, since these variables were approximately orthogonal. The validity of this model was finally checked against the yields reported by Wasserman et al. (1961) in a 6-cubic metre fermenter, thus confirming the capability of the model to provide a reliable basis for further scale-up on the production scale. (Refs. 17).

Prebiotics in piglet nutrition? Fermentation kinetics along the GI tract

NARCIS (Netherlands)

Awati, A.A.

2005-01-01

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

Fermented dairy food and CVD risk.

Science.gov (United States)

Tapsell, Linda C

2015-04-01

Fermented dairy foods such as yoghurt and cheese are commonly found in the Mediterranean diet. Recent landmark research has confirmed the effect of the Mediterranean diet on reducing the CVD risk, but the relative contributions of fermented dairy foods have not been fully articulated. The present study provides a review of the relationship between fermented dairy foods consumption and CVD risk in the context of the whole diet. Studies show that people who eat healthier diets may be more likely to consume yoghurt, so there is a challenge in attributing separate effects to yoghurt. Analyses from large population studies list yoghurt as the food most negatively associated with the risk of weight gain (a problem that may lead to CVD). There is some suggestion that fermented dairy foods consumption (yoghurt or cheese) may be associated with reduced inflammatory biomarkers associated with the development of CVD. Dietary trials suggest that cheese may not have the same effect on raising LDL-cholesterol levels as butter with the same saturated fat content. The same might be stated for yoghurt. The use of different probiotic cultures and other aspects of study design remain a problem for research. Nevertheless, population studies from a range of countries have shown that a reduced risk of CVD occurs with the consumption of fermented dairy foods. A combination of evidence is necessary, and more research is always valuable, but indications remain that fermented dairy foods such as cheese and yoghurt are integral to diets that are protective against CVD.

Genotypic and phenotypic characterization of garlic-fermenting lactic acid bacteria isolated from som-fak, a Thai low-salt fermented fish product

DEFF Research Database (Denmark)

Paludan-Müller, Christine; Valyasevi, R.; Huss, Hans Henrik

2002-01-01

AIMS: To evaluate the importance of garlic for fermentation of a Thai fish product, and to differentiate among garlic-/inulin-fermenting lactic acid bacteria (LAB) at strain level. METHODS AND RESULTS: Som-fak was prepared by fermentation of a mixture of fish, salt, rice, sucrose and garlic. p......H decreased to 4.5 in 2 days, but omitting garlic resulted in a lack of acidification. LAB were predominant and approximately one third of 234 isolated strains fermented garlic and inulin (the carbohydrate reserve in garlic). These strains were identified as Lactobacillus pentosus and Lact. plantarum...... AND IMPACT OF THE STUDY: The present study indicates the role of fructans (garlic/inulin) as carbohydrate sources for LAB. Fructan fermenters may have several biotechnological applications, for example, as probiotics....

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

DEFF Research Database (Denmark)

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

2011-01-01

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

Fermentation of molasses-flour mashes by acetone-butanol bacteria

Energy Technology Data Exchange (ETDEWEB)

Chekasina, E V

1962-01-01

With Clostridium acetobutylicum used in a continuous fermentation, where the mash passes through 5 to 12 fermenters, sufficient conversion of starch to mono- and disaccharides will occur; the number of fermenters were chosen and mash changed so that fresh mash remains for 34 hours in the cycle. After a 29 hour fermentation average yields were: acetone 4.5, ethanol 3.0, butanol 7.5%.

Extending our knowledge of fermentable, short-chain carbohydrates for managing gastrointestinal symptoms.

Science.gov (United States)

Barrett, Jacqueline S

2013-06-01

The Monash University low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet is now accepted as an effective strategy for managing symptoms of irritable bowel syndrome (IBS) in Australia, with interest expanding across the world. These poorly absorbed, short-chain carbohydrates have been shown to induce IBS symptoms of diarrhea, bloating, abdominal pain, and flatus due to their poor absorption, osmotic activity, and rapid fermentation. Four clinical trials have been published to date, all with significant symptomatic response to the low FODMAP diet. Up to 86% of patients with IBS have achieved relief of overall gastrointestinal symptoms and, more specifically, bloating, flatus, abdominal pain, and altered bowel habit from the approach. This review provides an overview of the low FODMAP diet and summarizes the research to date, emerging concepts, and limitations. FODMAPs are known to be beneficial to bowel health; the importance of this and how this should be considered in the clinical management of IBS is also discussed. A clinical management flowchart is provided to assist nutrition professionals in the use of this approach.

Health benefits of fermented foods: microbiota and beyond.

Science.gov (United States)

Marco, Maria L; Heeney, Dustin; Binda, Sylvie; Cifelli, Christopher J; Cotter, Paul D; Foligné, Benoit; Gänzle, Michael; Kort, Remco; Pasin, Gonca; Pihlanto, Anne; Smid, Eddy J; Hutkins, Robert

2017-04-01

Fermented foods and beverages were among the first processed food products consumed by humans. The production of foods such as yogurt and cultured milk, wine and beer, sauerkraut and kimchi, and fermented sausage were initially valued because of their improved shelf life, safety, and organoleptic properties. It is increasingly understood that fermented foods can also have enhanced nutritional and functional properties due to transformation of substrates and formation of bioactive or bioavailable end-products. Many fermented foods also contain living microorganisms of which some are genetically similar to strains used as probiotics. Although only a limited number of clinical studies on fermented foods have been performed, there is evidence that these foods provide health benefits well-beyond the starting food materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fermentation Industry.

Science.gov (United States)

Grady, C. P. L., Jr.; Grady, J. K.

1978-01-01

Presents a literature review of wastes from the fermentation industry, covering publications of 1976-77. This review focuses on: (1) alcoholic beverage production; (2) pharmaceuticals and biochemicals production; and (3) biomass production. A list of 62 references is also presented. (HM)

[Physiological response to acetic acid stress of Acetobacter pasteuranus during vinegar fermentation].

Science.gov (United States)

Qi, Zhengliang; Yang, Hailin; Xia, Xiaole; Wang, Wu; Leng, Yunwei; Yu, Xiaobin; Quan, Wu

2014-03-04

The aim of the study is to propose a dynamic acetic acid resistance mechanism through analysis on response of cellular morphology, physiology and metabolism of A. pasteurianus CICIM B7003 during vinegar fermentation. Vinegar fermentation was carried out in a Frings 9 L acetator by strain B7003 and cultures were sampled at different cellular growth phases. Simultaneously, percentage of capsular polysaccharide versus dry cells weight, ratio of unsaturated fatty acids to saturated fatty acids, transcription of acetic acid resistance genes, activity of alcohol respiratory chain enzymes and ATPase were detected for these samples to assay the responses of bacterial morphology, physiology and metabolism. When acetic acid was existed, no obvious capsular polysaccharide was secreted by cells. As vinegar fermentation proceeding, percentage of capsular polysaccharide versus dry cells weight was reduced from 2.5% to 0.89%. Ratio of unsaturated fatty acids to saturated fatty acids was increased obviously which can improve membrane fluidity. Also transcription level of acetic acid resistance genes was promoted. Interestingly, activity of alcohol respiratory chain and ATPase was not inhibited but promoted obviously with acetic acid accumulation which could provide enough energy for acetic acid resistance mechanism. On the basis of the results obtained from the experiment, A. pasteurianus CICIM B7003 relies mainly on the cooperation of changes of extracellular capsular polysaccharide and membrane fatty acids, activation of acid resistance genes transcription, enhancement of activity of alcohol respiratory chain and rapid energy production to tolerate acidic environment.

Generalised additive modelling approach to the fermentation process of glutamate.

Science.gov (United States)

Liu, Chun-Bo; Li, Yun; Pan, Feng; Shi, Zhong-Ping

2011-03-01

In this work, generalised additive models (GAMs) were used for the first time to model the fermentation of glutamate (Glu). It was found that three fermentation parameters fermentation time (T), dissolved oxygen (DO) and oxygen uptake rate (OUR) could capture 97% variance of the production of Glu during the fermentation process through a GAM model calibrated using online data from 15 fermentation experiments. This model was applied to investigate the individual and combined effects of T, DO and OUR on the production of Glu. The conditions to optimize the fermentation process were proposed based on the simulation study from this model. Results suggested that the production of Glu can reach a high level by controlling concentration levels of DO and OUR to the proposed optimization conditions during the fermentation process. The GAM approach therefore provides an alternative way to model and optimize the fermentation process of Glu. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Bioprocess Intensification of Beer Fermentation Using Immobilised Cells

Science.gov (United States)

Verbelen, Pieter J.; Nedović, Viktor A.; Manojlović, Verica; Delvaux, Freddy R.; Laskošek-Čukalović, Ida; Bugarski, Branko; Willaert, Ronnie

Beer production with immobilised yeast has been the subject of research for approximately 30 years but has so far found limited application in the brewing industry, due to engineering problems, unrealised cost advantages, microbial contaminations and an unbalanced beer flavor (Linko et al. 1998; Brányik et al. 2005; Willaert and Nedović 2006). The ultimate aim of this research is the production of beer of desired quality within 1-3 days. Traditional beer fermentation systems use freely suspended yeast cells to ferment wort in an unstirred batch reactor. The primary fermentation takes approximately 7 days with a subsequent secondary fermentation (maturation) of several weeks. A batch culture system employing immobilization could benefit from an increased rate of fermentation. However, it appears that in terms of increasing productivity, a continuous fermentation system with immobilization would be the best method (Verbelen et al. 2006). An important issue of the research area is whether beer can be produced by immobilised yeast in continuous culture with the same characteristic as the traditional method.

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.

Inoculated fermentation of green olives with potential probiotic Lactobacillus pentosus and Lactobacillus plantarum starter cultures isolated from industrially fermented olives.

Science.gov (United States)

Blana, Vasiliki A; Grounta, Athena; Tassou, Chrysoula C; Nychas, George-John E; Panagou, Efstathios Z

2014-04-01

The performance of two strains of lactic acid bacteria (LAB), namely Lactobacillus pentosus B281 and Lactobacillus plantarum B282, previously isolated from industrially fermented table olives and screened in vitro for probiotic potential, was investigated as starter cultures in Spanish style fermentation of cv. Halkidiki green olives. Fermentation was undertaken at room temperature in two different initial salt concentrations (8% and 10%, w/v, NaCl) in the brines. The strains were inoculated as single and combined cultures and the dynamics of their population on the surface of olives was monitored for a period of 114 days. The survival of inoculated strains on olives was determined using Pulsed Field Gel Electrophoresis (PFGE). Both probiotic strains successfully colonized the olive surface at populations ranged from 6.0 to 7.0 log CFU/g throughout fermentation. PFGE analysis revealed that L. pentosus B281 presented higher colonization in both salt levels at the end of fermentation (81.2% and 93.3% in 8% and 10% NaCl brines, respectively). For L. plantarum B282 a high survival rate (83.3%) was observed in 8% NaCl brines, but in 10% NaCl the strain could not colonize the surface of olives. L. pentosus B281 also dominated over L. plantarum B282 in inoculated fermentations when the two strains were used as combined culture. The biochemical profile (pH, organic acids, volatile compounds) attained during fermentation and the sensory analysis of the final product indicated a typical lactic acid fermentation process of green olives. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fermented liquid feed - Feed processing has a big impact on microbial degradation of free lysine during fermentation

DEFF Research Database (Denmark)

Canibe, Nuria; Jensen, Bent Borg

2010-01-01

In order to investigate the influence of feed processing on the microbial degradation of free lysine during fermentation of liquid feed, a study at laboratory scale was carried out. Based on a standard Danish grower diet with extra free amino acids added, two treatments were prepared: treatment 1...... a few hours of fermentation, the levels in both treatments became similar. The concentration of acetic acid was higher in the mixture containing the mash feed than in that containing the pelleted feed. The disappearance of free lysine was much higher when mash feed was fermented than when the same...

La fermentation acétonobutylique. Synthèse bibliographique et orientations actuelles Butanol-Acetone Fermentation. Bibliographie Synthesis and Current Trends

Directory of Open Access Journals (Sweden)

Marchal R.

2006-11-01

Full Text Available Cet article présente une synthèse des connaissances sur la fermentation acétonobutylique tant d'un point de vue microbiologique que technologique. Divers aspects du métabolisme et de la régulation du microorganisme mis en oeuvre sont abordés. Les performances de la fermentation sur ses substrats traditionnels (farine de maïs ou mélasses sont comparées avec celles qui ont été récemment obtenues à partir du topinambour à l'Institut Français du Pétrole, dans le cadre d'un nouveau développement de cette fermentation pour la production de carburants. This article gives a synthesis of what is known about butylacetone fermentation from both the microbiological and technological standpoints. Different aspects of the metabolism of the microorganism used and of how it is regulated are considered. The performances of fermentation on traditional substrates (cornmeal or molasses are compared with those recently obtained using Jerusalem artichokes at Institut Français du Pétrole as part of a new project on this fermentation for the purpose of producing substitute fuel.

[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.

Production of fermented probiotic beverages from milk permeate enriched with whey retentate and identification of present lactic acid bacteria

Directory of Open Access Journals (Sweden)

Jagoda Šušković

2009-03-01

Full Text Available In this research the application of bacterial strains Lactobacillus acidophilus M92, Lactobacillus plantarum L4 and Enterococcus faecium L3 in the production of fermented probiotic beverages from milk permeate enriched with 10 % (v/v whey retentate, was investigated. In the previous researches of probiotic concept, probiotic properties of these three strains of lactic acid bacteria have been defined. At the end of controlled fermentation, probiotic strains have produced 7.4 g/L lactic acid, pH was decreased to 4.7, and number of live cells was around 108 CFU/mL. Number of viable count of probiotic bacteria, which were identified with RAPD (Random Amplified Polymorphic DNAmethod, was maintained at around 107 CFU/mL during 28 days of the preservation at 4 °C. Furthermore, a spontaneous fermentation of milk permeate enriched with 10 % (v/v of whey retentate was carried out and lactic acid bacteria present in these substrates were isolated. All of these bacterial strains have rapidly acidified the growth media and have shown antibacterial activity against chosen test-microorganisms, what are important properties of potential starter cultures for the fermentation of dairy products. The results of biochemical API analysis have identified isolated strains as Lactococcus lactis subsp. lactis and Lactobacillus helveticus.

Clinical significance of fermentation and lactose malabsorption

OpenAIRE

Olesen, Merete; Gudmand-Høyer, Eivind

2001-01-01

Fermentation, the bacterial process of gaining energy from the breakdown of carbohydrates, takes place in the human large intestine as well as that of the animals. This process is important for the health of the colon. Due to changing dietary habits, the available substrates for fermentation in the human colon are scarce, and this fact may contribute to the increased number of colonic diseases in the Western world. Lactose in lactose-maldigesters increase the amounts of fermentable substrate,...

Methane and organic fertilizers from wood waste and manure fermentations

Energy Technology Data Exchange (ETDEWEB)

Romashkevich, I F; Karelina, G N

1961-01-01

Fermentation of sawdust of foliate trees by mesophyllic microflora is feasible, producing CH/sub 4/; the yield of gas is 500 cu m/ton, which surpasses that from manure and other agricultural wastes. Preliminary acid hydrolysis is unnecessary. At 5% organic matter, sawdust fermentation proceeds normally and with good yield, but 10% initial concentration of organic matter results in poor performance. Fermentation of common manure, that of sawdust and manure, or that of sawdust alone yields essentially the same gases. Fir sawdust does not ferment, but it does not stop manure or ash sawdust from fermenting if mixed with these. Fermented sawdust behaves like a fertilizer; it is beneficial to plants and crops. Nonfermented sawdust does not. Lupine N content is increased by both fermented and nonfermented sawdusts.

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.

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.

System for extracting protein from a fermentation product

Science.gov (United States)

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

2016-04-26

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

Method for extracting protein from a fermentation product

Science.gov (United States)

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

2014-02-18

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

Probiotic Delivery through Fermentation: Dairy vs. Non-Dairy Beverages

Directory of Open Access Journals (Sweden)

Chaminda Senaka Ranadheera

2017-12-01

Full Text Available Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host, mainly through the process of replacing or including beneficial bacteria in the gastrointestinal tract. Fermented dairy foods such as yogurt, fermented milk and cheese are the major vehicle in delivering probiotics, and probiotic delivery have been traditionally associated with these fermented dairy foods. Additionally, many other non-dairy probiotic products and non-food form such as capsules, pills and tablets are also available and some of these non-food forms are highly popular among the consumers. Certain non-dairy probiotic foods, especially beverages that are non-fermented products, can also play an important role in probiotic delivery. There is an increasing demand for non-dairy probiotic foods (both fermented and non-fermented including fruit and vegetable juices, soy and certain cereal products due to vegetarianism, lactose intolerance and dairy allergies, as well as interest in low cholesterol foods. In this context, this review mainly focus on the different types of probiotic food products including beverages with special reference to their viability followed by a brief account on the applicability of using fermented and non-fermented beverage products in probiotic delivery.

Influence of sodium chloride on wine yeast fermentation performance

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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

Recent advances in microbial fermentation for dairy and health

Science.gov (United States)

Arendt, Elke; Hill, Colin; Stanton, Catherine; Ross, R Paul

2017-01-01

Microbial fermentation has been used historically for the preservation of foods, the health benefits of which have since come to light. Early dairy fermentations depended on the spontaneous activity of the indigenous microbiota of the milk. Modern fermentations rely on defined starter cultures with desirable characteristics to ensure consistency and commercial viability. The selection of defined starters depends on specific phenotypes that benefit the product by guaranteeing shelf life and ensuring safety, texture, and flavour. Lactic acid bacteria can produce a number of bioactive metabolites during fermentation, such as bacteriocins, biogenic amines, exopolysaccharides, and proteolytically released peptides, among others. Prebiotics are added to food fermentations to improve the performance of probiotics. It has also been found that prebiotics fermented in the gut can have benefits that go beyond helping probiotic growth. Studies are now looking at how the fermentation of prebiotics such as fructo-oligosaccharides can help in the prevention of diseases such as osteoporosis, obesity, and colorectal cancer. The potential to prevent or even treat disease through the fermentation of food is a medically and commercially attractive goal and is showing increasing promise. However, the stringent regulation of probiotics is beginning to detrimentally affect the field and limit their application. PMID:28649371

Effect of sweet yeast bread formula on evaluating rapid mix test

Directory of Open Access Journals (Sweden)

Petra Dvořáková

2011-01-01

Full Text Available The aim of this work was to detect how different sweet yeast bread formulas influence results of rapid mix test and by the help of sensory analysis to discover consumer preferences and possible benefit and use in bakery industry. Applied raw materials (ground wheat flour T 530, yeast, sugar, salt, oil, egg, improver Hit along with basic formula were taken from the Varmužova bakery in Boršice by Buchlovice. The basic formula served as a standard (I, other six formulas were then determined (II–VII. In each formula, the rate of yeast, sugar or oil was altered in the range of ± 10% compared with the standard. Flour bread-making quality – Hagberg Falling number [s], Sedimentation index [ml], wet gluten [%], ash [%], moisture [%], binding capacity [%], granulation [%], alveographic energy [10−4J] and alveographic rate P/L – was measured. Rapid mix test and parameters like pastry weight, volume, shape, dough yield, pastry yield, baking loss, penetration and sensory analysis were determined. To establish yeast fermentation activity, Engelke fermentation test was applied. The most evident differences among the samples appeared in the volume and shape. The results of sensory analysis showed that the samples with higher rate of altered raw materials were evaluated as the best.

Spontaneous Food Fermentations and Potential Risks for Human Health

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Vittorio Capozzi

2017-09-01

Full Text Available Fermented foods and beverages are a heterogeneous class of products with a relevant worldwide significance for human economy, nutrition and health for millennia. A huge diversity of microorganisms is associated with the enormous variety in terms of raw materials, fermentative behavior and obtained products. In this wide microbiodiversity it is possible that the presence of microbial pathogens and toxic by-products of microbial origin, including mycotoxins, ethyl carbamate and biogenic amines, are aspects liable to reduce the safety of the consumed product. Together with other approaches (e.g., use of preservatives, respect of specific physico-chemical parameters, starter cultures technology has been conceived to successfully dominate indigenous microflora and to drive fermentation to foresee the desired attributes of the matrix, assuring quality and safety. Recent trends indicate a general return to spontaneous food fermentation. In this review, we point out the potential risks for human health associated with uncontrolled (uninoculated food fermentation and we discuss biotechnological approaches susceptible to conciliate fermented food safety, with instances of an enhanced contribution of microbes associated to spontaneous fermentation.

Quality of Bread Supplemented with Antrodia
salmonea-Fermented Grains

Science.gov (United States)

Chien, Rao-Chi; Ulziijargal, Enkhjargal

2016-01-01

Summary Fermented grains of buckwheat, oat, embryo rice and wheat, which were prepared by solid-state fermentation with Antrodia salmonea, and the mycelium was used to substitute 7% of wheat flour to make bread. No difference in proximate composition, texture profile and contents of non-volatile taste components was observed among bread samples. White bread and bread supplemented with mycelium and fermented grains looked different. Bread supplemented with fermented grains had similar thermal properties, which differed from those of white bread and bread supplemented with mycelium. Bread supplemented with fermented grains contained substantial mass fractions (on dry mass basis) of adenosine (0.92–1.96 µg/g), ergosterol (24.53–30.12 µg/g), ergothioneine (2.16–3.18 µg/g) and γ-aminobutyric acid (2.20–2.45 µg/g). In addition, bread supplemented with mycelium contained lovastatin (0.43 µg/g). White bread and bread supplemented with fermented grains had similar sensory results. Overall, fermented grains could be incorporated into bread to provide beneficial effects. PMID:27904408

Quality of Bread Supplemented with Antrodia salmonea-Fermented Grains

Directory of Open Access Journals (Sweden)

Rao-Chi Chien

2016-01-01

Full Text Available Fermented grains of buckwheat, oat, embryo rice and wheat, which were prepared by solid-state fermentation with Antrodia salmonea, and the mycelium was used to substitute 7 % of wheat flour to make bread. No difference in proximate composition, texture profile and contents of non-volatile taste components was observed among bread samples. White bread and bread supplemented with mycelium and fermented grains looked different. Bread supplemented with fermented grains had similar thermal properties, which differed from those of white bread and bread supplemented with mycelium. Bread supplemented with fermented grains contained substantial mass fractions (on dry mass basis of adenosine (0.92–1.96 μg/g, ergosterol (24.53–30.12 μg/g, ergothioneine (2.16–3.18 μg/g and γ-aminobutyric acid (2.20–2.45 μg/g. In addition, bread supplemented with mycelium contained lovastatin (0.43 μg/g. White bread and bread supplemented with fermented grains had similar sensory results. Overall, fermented grains could be incorporated into bread to provide beneficial effects.

Influence of Different Fermentation Strategies on the Phenolic Profile of Bilberry Wine (Vaccinium myrtillus L.).

Science.gov (United States)

Behrends, Annika; Weber, Fabian

2017-08-30

Polyphenol rich and especially anthocyanin rich berries like bilberries (Vaccinium myrtillus L.) and derived products such as wine have enjoyed increasing popularity. During winemaking and aging, the phenolic profile undergoes distinct changes, a phenomenon that has been well investigated in grape wine but not in bilberry wine. The present study determined the influence of different fermentation strategies including various pre- and postfermentative heating and cooling concepts on the phenolic profile of bilberry wine. Besides significant differences in total anthocyanin and tannin concentrations, the different fermentation strategies resulted in distinguishable anthocyanin profiles. A very fast aging manifested by a rapid decrease in monomeric anthocyanins of up to 98% during a 12 week storage and a coincident formation of polymeric pigments and pyranoanthocyanins was observed. Several well-known processes associated with production and aging of wine were much more pronounced in bilberry wine compared to grape wine.

Irradiation of meat for the production of fermented sausage

International Nuclear Information System (INIS)

Dickson, J.S.; Maxcy, R.B.

1985-01-01

A study assessing the potential of gamma irradiation for reducing pathogenic microflora in the production of fermented sausage revealed that an irradiation dose of 500 Krad could reduce total aerobic microflora in commercial sausage meat batter for up to 2.2 log cycles. Coliform and staphylococci counts were reduced to acceptably safe levels, allowing the use of a lower inoculum level, a longer fermentation time, and a more uniform fermentation and fermented product

The microbial diversity of traditional spontaneously fermented lambic beer

OpenAIRE

Spitaels, Freek; Wieme, Anneleen D.; Janssens, Maarten; Aerts, Maarten; Daniel, Heide-Marie; Van Landschoot, Anita; De Vuyst, Luc; Vandamme, Peter

2014-01-01

Lambic sour beers are the products of a spontaneous fermentation that lasts for one to three years before bottling. The present study determined the microbiota involved in the fermentation of lambic beers by sampling two fermentation batches during two years in the most traditional lambic brewery of Belgium, using culture-dependent and culture-independent methods. From 14 samples per fermentation, over 2000 bacterial and yeast isolates were obtained and identified. Although minor variations i...

Irradiation of meat for the production of fermented sausage

Energy Technology Data Exchange (ETDEWEB)

Dickson, J. S.; Maxcy, R. B.

1985-07-15

A study assessing the potential of gamma irradiation for reducing pathogenic microflora in the production of fermented sausage revealed that an irradiation dose of 500 Krad could reduce total aerobic microflora in commercial sausage meat batter for up to 2.2 log cycles. Coliform and staphylococci counts were reduced to acceptably safe levels, allowing the use of a lower inoculum level, a longer fermentation time, and a more uniform fermentation and fermented product.

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.

The effect of microbial starter composition on cassava chips fermentation for the production of fermented cassava flour

Science.gov (United States)

Kresnowati, M. T. A. P.; Listianingrum, Zaenudin, Ahmad; Trihatmoko, Kharisrama

2015-12-01

The processing of cassava into fermented cassava flour (fercaf) or the widely known as modified cassava flour (mocaf) presents an alternative solution to improve the competitiveness of local foods and to support national food security. However, the mass production of fercaf is being limited by several problems, among which is the availability of starter cultures. This paper presents the mapping of the effect of microbial starter compositions on the nutritional content of fercaf in order to obtain the suitable nutritional composition. Based on their enzymatic activities, the combination of Lactobacillus plantarum, Bacillus subtilis, and Aspergillus oryzae were tested during the study. In addition, commercial starter was also tested. During the fermentation, the dynamics in microbial population were measured as well as changes in cyanogenic glucoside content. The microbial starter composition was observed to affect the dynamics in microbial populationcynaogenic glucoside content of the produced fercaf. In general, steady state microbial population was reached within 12 hours of fermentation. Cyanogenic glucoside was observed to decrease along the fermentation.

Improved fermentative alcohol production. [Patent application

Science.gov (United States)

Wilke, C.R.; Maiorella, B.L.; Blanch, H.W.; Cysewski, G.R.

1980-11-26

An improved fermentation process is described for producing alcohol which includes the combination of vacuum fermentation and vacuum distillation. Preferably, the vacuum distillation is carried out in two phases, one a fermentor proper operated at atmospheric pressure and a flash phase operated at reduced pressure with recycle of fermentation brew having a reduced alcohol content to the fermentor, using vapor recompression heating of the flash-pot recycle stream to heat the flash-pot or the distillation step, and using water load balancing (i.e., the molar ratio of water in the fermentor feed is the same as the molar ratio of water in the distillation overhead).

Complex media from processing of agricultural crops for microbial fermentation

DEFF Research Database (Denmark)

Thomsen, M.H.

2005-01-01

, is converted to a basic, universal fermentation medium by lactic acid fermentation, is outlined. The resulting all-round fermentation medium can be used for the production of many useful fermentation products when added a carbohydrate source, which could possibly be another agricultural by-product. Two...... examples of such products-polylactic acid and L-lysine-are given. A cost calculation shows that this fermentation medium can be produced at a very low cost approximate to 1.7 Euro cent/kg, when taking into account that the green crop industry has expenses amounting to 270,000 Euro/year for disposal...... of the brown juice. A newly built lysine factory in Esbjerg, Denmark, can benefit from this process by buying a low price medium for the fermentation process instead of more expensive traditional fermentation liquids such as corn steep liquor....

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.

Thermophilic Dry Methane Fermentation of Distillation Residue Eluted from Ethanol Fermentation of Kitchen Waste and Dynamics of Microbial Communities.

Science.gov (United States)

Huang, Yu-Lian; Tan, Li; Wang, Ting-Ting; Sun, Zhao-Yong; Tang, Yue-Qin; Kida, Kenji

2017-01-01

Thermophilic dry methane fermentation is advantageous for feedstock with high solid content. Distillation residue with 65.1 % moisture content was eluted from ethanol fermentation of kitchen waste and subjected to thermophilic dry methane fermentation, after adjusting the moisture content to 75 %. The effect of carbon to nitrogen (C/N) ratio on thermophilic dry methane fermentation was investigated. Results showed that thermophilic dry methane fermentation could not be stably performed for >10 weeks at a C/N ratio of 12.6 and a volatile total solid (VTS) loading rate of 1 g/kg sludge/d; however, it was stably performed at a C/N ratio of 19.8 and a VTS loading rate of 3 g/kg sludge/d with 83.4 % energy recovery efficiency. Quantitative PCR analysis revealed that the number of bacteria and archaea decreased by two orders of magnitude at a C/N ratio of 12.6, whereas they were not influenced at a C/N ratio of 19.8. Microbial community analysis revealed that the relative abundance of protein-degrading bacteria increased and that of organic acid-oxidizing bacteria and acetic acid-oxidizing bacteria decreased at a C/N ratio of 12.6. Therefore, there was accumulation of NH 4 + and acetic acid, which inhibited thermophilic dry methane fermentation.

Ultrasonic Monitoring of the Progress of Lactic Acid Fermentation

Science.gov (United States)

Masuzawa, Nobuyoshi; Kimura, Akihiro; Ohdaira, Etsuzo

2003-05-01

Promotion of lactic acid fermentation by ultrasonic irradiation has been attempted. It is possible to determine the progress of fermentation and production of a curd, i.e., yoghurt and or kefir, by measuring acidity using a pH meter. However, this method is inconvenient and indirect for the evaluation of the progress of lactic acid fermentation under anaerobic condition. In this study, an ultrasonic monitoring method for evaluating the progress of lactic acid fermentation was examined.

Heat and Mass Transfer Measurements for Tray-Fermented Fungal Products

Science.gov (United States)

Jou, R.-Y.; Lo, C.-T.

2011-01-01

In this study, heat and mass transfer in static tray fermentation, which is widely used in solid-state fermentation (SSF) to produce fungal products, such as enzymes or koji, is investigated. Specifically, kinetic models of transport phenomena in the whole-tray chamber are emphasized. The effects of temperature, moisture, and humidity on microbial growth in large-scale static tray fermentation are essential to scale-up SSF and achieve uniform fermentation. In addition, heat and mass transfer of static tray fermentation of Trichoderma fungi with two tray setups—traditional linen coverings and stacks in a temperature-humidity chamber is examined. In both these setups, the following factors of fermentation were measured: air velocity, air temperature, illumination, pH, carbon dioxide (CO2) concentration, and substrate temperature, and the effects of bed height, moisture of substrate, and relative humidity of air are studied. A thin (1 cm) bed at 28 °C and 95 % relative humidity is found to be optimum. Furthermore, mixing was essential for achieving uniform fermentation of Trichoderma fungi. This study has important applications in large-scale static tray fermentation of fungi.

Selection of Yeast Strains for Tequila Fermentation Based on Growth Dynamics in Combined Fructose and Ethanol Media.

Science.gov (United States)

Aldrete-Tapia, J A; Miranda-Castilleja, D E; Arvizu-Medrano, S M; Hernández-Iturriaga, M

2018-02-01

The high concentration of fructose in agave juice has been associated with reduced ethanol tolerance of commercial yeasts used for tequila production and low fermentation yields. The selection of autochthonous strains, which are better adapted to agave juice, could improve the process. In this study, a 2-step selection process of yeasts isolated from spontaneous fermentations for tequila production was carried out based on analysis of the growth dynamics in combined conditions of high fructose and ethanol. First, yeast isolates (605) were screened to identify strains tolerant to high fructose (20%) and to ethanol (10%), yielding 89 isolates able to grow in both conditions. From the 89 isolates, the growth curves under 8 treatments of combined fructose (from 20% to 5%) and ethanol (from 0% to 10%) were obtained, and the kinetic parameters were analyzed with principal component analysis and k-means clustering. The resulting yeast strain groups corresponded to the fast, medium and slow growers. A second clustering of only the fast growers led to the selection of 3 Saccharomyces strains (199, 230, 231) that were able to grow rapidly in 4 out of the 8 conditions evaluated. This methodology differentiated strains phenotypically and could be further used for strain selection in other processes. A method to select yeast strains for fermentation taking into account the natural differences of yeast isolates. This methodology is based on the cell exposition to combinations of sugar and ethanol, which are the most important stress factors in fermentation. This strategy will help to identify the most tolerant strain that could improve ethanol yield and reduce fermentation time. © 2018 Institute of Food Technologists®.

Industrial alcohol production via whey and grain fermentation

Energy Technology Data Exchange (ETDEWEB)

Friend, B A; Cunningham, M L; Shahani, K M

1982-01-01

Six strains of a trained lactose fermenting Kluyveromyces yeast were examined for their ability to utilise lactose in sweet-whey permeate. All strains of K. fragilis tested reduced the concentration of the 5.1% lactose, initially present in whey permeate, to 0.1-0.2% within 48h. Periodic adjustment to maintain the pH during fermentation did not alter the lactose utilisation. The fermentation efficiency of K. fragilis was then compared with that of a mixture of K. fragilis and the classical alcohol fermenter Saccharomyces cerevisiae to verify that no unfavourable interactions occurred in the mixed culture. There were no differences in lactose utilisation or ethanol production between the two groups; both produced approximately 2% ethanol within 24h. This represented approximately 80% of the alcohol which theoretically could be produced from the 5.1% lactose present in the permeate. Whey permeate was also incorporated into the classical grain fermentation by substitution for one-half the water normally added to produce the mash. Fermentation was nearly complete by 36h and alcohol levels ranged from 9.7% for the mixed culture to 9.4% for the K. fragilis and 9.3% for the S. cerevisiae. Since the whey provided significant levels of fermentable sugars, studies were also conducted in which undiluted whey permeate was substituted for all of the water in the mash and the amount of grain was reduced by 20%. At the end of 36h K. fragilis produced 10.9% alcohol and at 60 h of fermentation the level had reached 12.2%. When whole sweet-whey was used, similar levels of alcohol were produced. (Refs. 20).

Use of milk-based kombucha inoculum for milk fermentation

Directory of Open Access Journals (Sweden)

Kolarov Ljiljana A.

2009-01-01

Full Text Available In this investigation fermented milk beverages with 0.9% of milk fat were produced using 10 and 15% (v/v of traditional and milk-based kombucha inoculum by application of appropriate technological process. Milk fermentation using two types and concentrations of kombucha inoculum were stopped when the pH reached 4.5. Sigmoidal fermentation profiles were noticed with traditional kombucha inoculums and linear with milk-based kombucha inoculums. Chemical content and physico-chemical characteristics of kombucha fermented milk beverages were typical and yoghurt-like for all obtained products. The best textural and sensory characteristics possesed beverage obtained in fermentation of milk using 10% (v/v of milk-based kombucha inoculum.

Computer evaluation of the results of batch fermentations

Energy Technology Data Exchange (ETDEWEB)

Nyeste, L; Sevella, B

1980-01-01

A useful aid to the mathematical modeling of fermentation systems, for the kinetic evaluation of batch fermentations, is described. The generalized logistic equation may be used to describe the growth curves, substrate consumption, and product formation. A computer process was developed to fit the equation to experimental points, automatically determining the equation constants on the basis of the iteration algorithm of the method of non-linear least squares. By fitting the process to different master programs of various fermentations, the complex kinetic evaluation of fermentations becomes possible. Based on the analysis easily treatable generalized logistic equation, it is possible to calculate by computer different kinetic characteristics, e.g. rates, special rates, yields, etc. The possibility of committing subjective errors was reduced to a minimum. Employment of the method is demonstrated on some fermentation processes and problems arising in the course of application are discussed.

Influence of black tea concentrate on kombucha fermentation

Directory of Open Access Journals (Sweden)

Malbaša Radomir V.

2006-01-01

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

Accelerated fermentation of cheese whey. Developing the system

Energy Technology Data Exchange (ETDEWEB)

Bechtle, R M; Claydon, T J

1971-01-01

A system for accelerated fermentation of cheese wheys requires a mixed yeast and lactose-fermenting bacterial culture. The air flow required (110 ml/min/1./1% of lactose) was proportional to the concentration of wheys in the media. Yeast cell-mass production by accelerated fermentation was equal to or greater than the whey concentration factor when compared with yeast production of single yeast strain production on unconcentrated wheys. Generally, on triple strength wheys, yeast production was approximately 1 lb/gallon of medium. Fermentation media formulas were developed with whey analysis, shake culture, and fermentor trials. The formula used with a specific whey must be adequate to supplement the mineral deficiencies in the whey and to provide trace elements and nutrients essential for maximum microbial growth. High-rate aeration was required for both respiration of the microbial culture and to purge the ferment of volatile metabolites, whose presence depressed microbial cell synthesis.

Novel strategies for control of fermentation processes

DEFF Research Database (Denmark)

Mears, Lisa; Stocks, Stuart; Sin, Gürkan

Bioprocesses are inherently sensitive to fluctuations in processing conditions and must be tightly regulated to maintain cellular productivity. Industrial fermentations are often difficult to replicate across production sites or between facilities as the small operating differences in the equipment...... of a fermentation. Industrial fermentation processes are typically operated in fed batch mode, which also poses specific challenges for process monitoring and control. This is due to many reasons including non-linear behaviour, and a relatively poor understanding of the system dynamics. It is therefore challenging...

Functional Properties of Microorganisms in Fermented Foods

Directory of Open Access Journals (Sweden)

Jyoti Prakash Tamang

2016-04-01

Full Text Available Fermented foods have unique functional properties imparting some health benefits to consumers due to presence of functional microorganisms, which possess probiotics properties, antimicrobial, antioxidant, peptide production, etc. Health benefits of some global fermented foods are synthesis of nutrients, prevention of cardiovascular disease, prevention of cancer, gastrointestinal disorders, allergic reactions, diabetes, among others. The present paper is aimed to review the information on some functional properties of the microorganisms associated with fermented foods and beverages, and their health-promoting benefits to consumers.

Kinetic and stoichiometric modelling of acidogenic fermentation of glucose and fructose

International Nuclear Information System (INIS)

Fernandez, F.J.; Villasenor, J.; Infantes, D.

2011-01-01

In this work, a model based on Monod equation for the description of the acidogenic fermentation of glucose and fructose as the main substrates contained in the winery wastewater was developed. The data used for calibration and validation of the model parameters were obtained from an acidogenic mixed culture fermenting glucose and fructose in a batch reactor at 35 o C and pH 5. The calibrated model accurately describes the experimental results from biomass growth, substrate consumption and fermentation products generation. The results showed that the microorganisms growth rate and biomass yield were higher when glucose was used as substrate: μ max-Glucose = 0.163 h -1 , μ max-Fructose = 0.108 h -1 , Y x-Glucose = 0.027 g VSS per mmol Glucose and Y x-Fructose 0.017 g VSS per mmol Fructose. Regarding to the fermentation products, the acetic acid was the main fermentation product obtained in both fermentations, followed by lactic and butyric acid. Comparing glucose and fructose fermentations, the main difference was the yield of butyric acid in both fermentations, 0.249 mol per mol Glucose and 0.131 mol per mol Fructose since the other acids concentration were quite similar. In the case of the H 2 production, it was 0.76 mol H 2 per mol Glucose while 0.85 was the yield in fructose fermentation. -- Highlights: → Acidogenic fermentation of glucose and fructose was studied. → A model describing the kinetics and stoichiometry of the fermentation was developed. → The model developed predicted accurately the substrate, products and biomass profiles along the fermentation process. → The microorganisms growth rate was higher in the glucose fermentation. → The fructose fermentation presented higher hydrogen yields.

Chemical mechanism of the fluoride-inhibition of fermentation

Energy Technology Data Exchange (ETDEWEB)

Warburg, O; Christian, W

1941-08-01

Among the fluoride-sensitive fermentation elements, enolase is the most sensitive. An investigation was made, quantitatively, of fluoride inhibition for chemically pure magnesium-enolase using an optical enolase test. Data show that the effective compound for fluoride inhibition is a complex magnesium-fluoro-phosphate and that the magnesium-fluoro-phosphate inhibits fermentation by combining proportionally to its concentration with the ferment-protein in a dissociating manner.

Mystery behind Chinese liquor fermentation

OpenAIRE

Jin, Guangyuan; Zhu, Yang; Xu, Yan

2017-01-01

Background Chinese liquor, a very popular fermented alcoholic beverage with thousands of years’ history in China, though its flavour formation and microbial process have only been partly explored, is facing the industrial challenge of modernisation and standardisation for food quality and safety as well as sustainability. Meanwhile, the hidden knowledge behind the complicated and somehow empirical solid-state fermentation process of Chinese liquor can enrich the food sector to improve our qua...

Aerobic Stability and Effects of Yeasts during Deterioration of Non-fermented and Fermented Total Mixed Ration with Different Moisture Levels

OpenAIRE

W. Hao; H. L. Wang; T. T. Ning; F. Y. Yang; C. C. Xu

2015-01-01

The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR). The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted...

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.

Effects of Fermentation on the Fatty Acids, Sterols and ...

African Journals Online (AJOL)

Walnut contains fatty acids that are essential for infants' growth and development. This study explored the possibility of fermenting walnuts for use as a complementary food. Raw fermented (RF), cooked fermented (CF), raw unfermented (RUF) and cooked unfermented (CUF) samples of walnuts products were analyzed for ...

Hybridization of halotolerant yeast for alcohol fermentation

International Nuclear Information System (INIS)

Limtong, S.

1991-01-01

Attempt have been made to construct a new yeast strain from alcohol fermenting strains and salt tolerant strains. It is anticipated that the new yeast strain will be able to ferment alcohol in molasses mash with high salinity, up to 3% of NaCl. Another characteristics is its ability to tolerate up to 40 C temperature which is desirable for alcohol fermentation in tropical countries. Commercial and wild strains of Saccharomyces cerevisiae were screened for their fermenting ability and strain SC90, 191 TJ3, and AM12 were selected as parental strains for fusion among themselves and with other halo tolerant species. Halo tolerant strains selected at 5% NaCl in molasses mash were tentatively identified as Torulopsis grabrata, T. candida, T. Bovina and S. Rouxii whereas all of those strains selected at 17% NaCl were Citeromyces sp. It was found that fusant TA73 derived from wild strain and sake fermenting strain performed best among 4,087 fusants investigated. This fusant fermented much better than their parental strains when salt concentrations were increased to 5 and 7% NaCl. Experiment was carried out in fermentor, 1.5 liter working volume using molasses mash with 3% NaCl and temperature was controlled at 35 degree C. Fermentation rate of TA73, TJ3 and AM12 were 2.17, 1.50 and 1.87 g/L/hr respectively, Maximum ethanol concentration obtained were 7.6, 6.7 and 7.4% by weight after 60 and 78 hours respectively. Other fusants derived from fusion of Saccharomyces cerevisiae with other halo tolerant species were mostly inferior to their parental strains and only 7 fusants were slightly better than parental strains. (author)

Extração e caracterização de hemiceluloses de Pinus radiata e sua viabilidade para a produção de bioetanol Extraction and characterization of hemicelluloses from Pinus radiata and its feasibility for bioethanol production

Directory of Open Access Journals (Sweden)

Pablo Reyes

2013-02-01

neutral aqueous solutions of hemicelluloses from Pinus radiata wood chips and investigate their feasibility for bioethanol production. Hemicelluloses in P. radiata represented 26 g/100 g wood (o.d.w. and hexoses are responsible for approximately 64% of this amount. According to the different extraction conditions, approximately 50% of the hemicellulosic fraction was solubilized and recovered after precipitation with ethanol. The recovered hemicellulosic fractions were in the form of oligomers with weight-average molecular weigth (Mw varying from 4x10³ to 4x10(5 g/mol. Hemicellulosic oligomers were hydrolyzed with dilute sulfuric acid and the hydrolysates concentrated until approximately 70 g/L of hexoses and fermented by Saccharomyces cerevisiae yeast. Fermentation results showed that sugar obtained from acid and neutral extractions were fermented to ethanol with maximum yields of 63% and 54% (22 g/ L and 19 g/L, respectively. The conversion of wood hemicellulosic substrates to ethanol is feasible but the low ethanol yields obtained make the process not economically attractive and optimization of the process or alternatives uses for hemicelluloses should be evaluated.

Fermentation of polysaccharides by Klebsiella and other facultative bacilli

Energy Technology Data Exchange (ETDEWEB)

Ochuba, G.U.; Von Riesen, V.L.

1980-05-01

Fermentations of 10 polysaccharides by species of the family Enterobacteriaceae were examined. Algin, guar, karaya, xanthan, and xylan were not fermented by any of the strains tested. Most of the activity was found in the tribe Klebsielleae. Klebseilla oxytoca fermented amylopectin (97% of the strains studied), carrageenan (100%), inulin (68%), polypectate (100%), and tragacanth (100%). Klebsiella pneumoniae fermented amylopectin (91%), carrageenan (100%), and tragacanth (86%). Carraggeenan was also fermented by Enterobacter aerogenes (100%), Enterobacter agglomerans (63%), Enterobacter cloacae (95%), and pectobacterium (38%). pectobacterium shared polypectate fermentation (100%) with K. oxytoca. With one exception, Serratia strains were negative on all polysaccharides. These results, along with other evidence, indicate that (i) the genus Klebsiella is biochemically the most versatile genus of the tribe, (ii) because of its distinct characteristics, K. oxytoca warrants species designation separate from K. pneumoniae, and (iii) some food additives generally considered indigestible can be metabolized by a few species of facultative bacilli, whereas others appear to be resistant.

Fermentation of polysaccharides by Klebsielleae and other facultative bacilli.

Science.gov (United States)

Ochuba, G U; von Riesen, V L

1980-01-01

Fermentations of 10 polysaccharides by species of the family Enterobacteriaceae were examined. Algin, guar, karaya, xanthan, and xylan were not fermented by any of the strains tested. Most of the activity was found in the tribe Klebsielleae. Klebsiella oxytoca fermented amylopectin (97% of the strains studied), carrageenan (100%), inulin (68%), polypectate (100%), and tragacanth (100%). Klebsiella pneumoniae fermented amylopectin (91%), carrageenan (100%), and tragacanth (86%). Carrageenan was also fermented by Enterobacter aerogenes (100%), Enterobacter agglomerans (63%), Enterobacter cloacae (95%), and Pectobacterium (38%). Pectobacterium shared polypectate fermentation (100%) with K. oxytoca. With one exception, Serratia strains were negative on all polysaccharides. These results, along with other evidence, indicate that (i) the genus Klebsiella is biochemically the most versatile genus of the tribe, (ii) because of its distinct characteristics, K. oxytoca warrants species designation separate from K. pneumoniae, and (iii) some food additives generally considered indigestible can be metabolized by a few species of facultative bacilli, whereas others appear to be resistant. PMID:7396489

Microbial production of four biodegradable siderophores under submerged fermentation.

Science.gov (United States)

Fazary, Ahmed E; Al-Shihri, Ayed S; Alfaifi, Mohammad Y; Saleh, Kamel A; Alshehri, Mohammed A; Elbehairi, Serag Eldin I; Ju, Yi-Hsu

2016-07-01

Four siderophore analogues were isolated and purified from Escherichia coli, Bacillus spp. ST13, and Streptomyces pilosus microorganisms under some specific submerged fermentation conditions. In order to evaluate the highest production of this siderophore analogues through the growth, a rapid spectrophotometric screening semi-quantitative method was used, in which interestingly the analogues were isolated in its own form not its iron chelate. After chromatographic separation, the chemical structures of the isolated and purified siderophores were illustrated using detailed spectroscopic techniques. The biodegradation studies were done on that four novel isolated and purified siderophores following OECD protocols. In addition, the bioactivities of these siderophores and their iron complexes were examined and evaluated. Copyright © 2016 Elsevier B.V. All rights reserved.

Mathematical models of ABE fermentation: review and analysis.

Science.gov (United States)

Mayank, Rahul; Ranjan, Amrita; Moholkar, Vijayanand S

2013-12-01

Among different liquid biofuels that have emerged in the recent past, biobutanol produced via fermentation processes is of special interest due to very similar properties to that of gasoline. For an effective design, scale-up, and optimization of the acetone-butanol-ethanol (ABE) fermentation process, it is necessary to have insight into the micro- and macro-mechanisms of the process. The mathematical models for ABE fermentation are efficient tools for this purpose, which have evolved from simple stoichiometric fermentation equations in the 1980s to the recent sophisticated and elaborate kinetic models based on metabolic pathways. In this article, we have reviewed the literature published in the area of mathematical modeling of the ABE fermentation. We have tried to present an analysis of these models in terms of their potency in describing the overall physiology of the process, design features, mode of operation along with comparison and validation with experimental results. In addition, we have also highlighted important facets of these models such as metabolic pathways, basic kinetics of different metabolites, biomass growth, inhibition modeling and other additional features such as cell retention and immobilized cultures. Our review also covers the mathematical modeling of the downstream processing of ABE fermentation, i.e. recovery and purification of solvents through flash distillation, liquid-liquid extraction, and pervaporation. We believe that this review will be a useful source of information and analysis on mathematical models for ABE fermentation for both the appropriate scientific and engineering communities.

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 %.

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

Science.gov (United States)

Buehler, Edward A.; Mesbah, Ali

2016-01-01

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

Wastewater recycling technology for fermentation in polyunsaturated fatty acid production.

Science.gov (United States)

Song, Xiaojin; Ma, Zengxin; Tan, Yanzhen; Zhang, Huidan; Cui, Qiu

2017-07-01

To reduce fermentation-associated wastewater discharge and the cost of wastewater treatment, which further reduces the total cost of DHA and ARA production, this study first analyzed the composition of wastewater from Aurantiochytrium (DHA) and Mortierella alpina (ARA) fermentation, after which wastewater recycling technology for these fermentation processes was developed. No negative effects of DHA and ARA production were observed when the two fermentation wastewater methods were cross-recycled. DHA and ARA yields were significantly inhibited when the wastewater from the fermentation process was directly reused. In 5-L fed-batch fermentation experiments, using this cross-recycle technology, the DHA and ARA yields were 30.4 and 5.13gL -1 , respectively, with no significant changes (P>0.05) compared to the control group, and the water consumption was reduced by half compared to the traditional process. Therefore, this technology has great potential in industrial fermentation for polyunsaturated fatty acid production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fermentation of cellulose and fatty acids with enrichments from sewage sludge

International Nuclear Information System (INIS)

Winter, J.U.; Cooney, C.L.

1980-01-01

A mixed culture enriched from sewage sludge and anaerobic digestor effluent was able to degrade cellulose and acetate rapidly and quantitatively to methane and carbon dioxide. The maximum specific rate of gas production was 87ml/gm cell-h, corresponding to a rate of cellulose utilization of 0.1g/g cells-h. Acetate, an intermediate in cellulose degradation, was fermented much more rapidly than butyrate or propionate; its maximum utilization rate was first order with a rate constant of 0.34h -1 . Addition of 2- 14 C-acetate to a digestor fed cellulose showed that 2% of the methyl groups were oxidized to carbon dioxide. When 1- 14 C-acetate was added to a similar digestor, 52% of the carboxyl groups were reduced to methane, suggesting that not all the carbon dioxide during simultaneous cellulose and acetate utilization is treated equally. The pulse addition of large amounts of acetate, propionate and butyrate to a cellulose fed digestor was also examined. (orig.)

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.

Bio-hydrogen production from hyacinth by anaerobic fermentation

International Nuclear Information System (INIS)

Cheng Jun; Zhou Junhu; Qi Feng; Xie Binfei; Cen Kefa

2006-01-01

The bio-hydrogen production from hyacinth by anaerobic fermentation of digested sludge is studied in this paper. The compositions of bio-gases and volatile fatty acids in fermentation liquids are determined on TRACE 2000 gas chromatography. It is found that the H 2 concentration in the biogas is 10%-20% and no CH 4 is detected. The bio-hydrogen production from hyacinth with the initial pH value of 5.5 is higher than that with the initial pH value of 4.5. The fermentation temperature of 55 C is better than that of 35 C, while the weight ratio of hyacinth to microorganism of 1:1 is better than that of 3:7. The highest hydrogen production of 122.3 mL/g is obtained when the initial pH value of fermentation solution is 5.5, the fermentation temperature is 55 C and the weight ratio of hyacinth to microorganism is 1:1. (authors)

Chemical oxygen demand reduction in a whey fermentation

Energy Technology Data Exchange (ETDEWEB)

Moresi, M; Colicchio, A; Sansovini, F; Sebastiani, E

1980-01-01

The efficiency of COD reduction in the fermentation of whey by Kluyveromyces fragilis IMAT 1872 was studied at various temperatures, lactose concentrations, air dilution ratios, and stirring speeds. Two different optimal sets of these variables were found according to whether the objective was the production of cell mass or the reduction of COD. The 2 sets were then compared to establish a strategy for the industrial development of this fermentation process. The experimental efficiencies of COD removal were submitted to analysis in a composite design. Only the O2 transfer coefficient factor and the stripping factor were significant. Therefore, the observations were fitted with a quadratic expression by using only these factors: the mean std. error was <6%. The yield of cells varied in this fermentation, but this parameter may be particularly useful for analyzing and optimizing any fermentation process when the culture medium is a mixture of carbohydrates or the main substrate is fully utilized during the initial stages of fermentation.

Establishing the relative importance of damaged starch and fructan as sources of fermentable sugars in wheat flour and whole meal bread dough fermentations.

Science.gov (United States)

Struyf, Nore; Laurent, Jitka; Lefevere, Bianca; Verspreet, Joran; Verstrepen, Kevin J; Courtin, Christophe M

2017-03-01

It is generally believed that maltose drives yeast-mediated bread dough fermentation. The relative importance of fructose and glucose, released from wheat fructan and sucrose by invertase, compared to maltose is, however, not documented. This is surprising given the preference of yeast for glucose and fructose over maltose. This study revealed that, after 2h fermentation of wheat flour dough, about 44% of the sugars consumed were generated by invertase-mediated degradation of fructan, raffinose and sucrose. The other 56% were generated by amylases. In whole meal dough, 70% of the sugars consumed were released by invertase activity. Invertase-mediated sugar release seems to be crucial during the first hour of fermentation, while amylase-mediated sugar release was predominant in the later stages of fermentation, which explains why higher amylolytic activity prolonged the productive fermentation time only. These results illustrate the importance of wheat fructan and sucrose content and their degradation for dough fermentations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prokaryotic community composition in alkaline-fermented skate (Raja pulchra).

Science.gov (United States)

Jang, Gwang Il; Kim, Gahee; Hwang, Chung Yeon; Cho, Byung Cheol

2017-02-01

Prokaryotes were extracted from skates and fermented skates purchased from fish markets and a local manufacturer in South Korea. The prokaryotic community composition of skates and fermented skates was investigated using 16S rRNA pyrosequencing. The ranges for pH and salinity of the grinded tissue extract from fermented skates were 8.4-8.9 and 1.6-6.6%, respectively. Urea and ammonia concentrations were markedly low and high, respectively, in fermented skates compared to skates. Species richness was increased in fermented skates compared to skates. Dominant and predominant bacterial groups present in the fermented skates belonged to the phylum Firmicutes, whereas those in skates belonged to Gammaproteobacteria. The major taxa found in Firmicutes were Atopostipes (Carnobacteriaceae, Lactobacillales) and/or Tissierella (Tissierellaceae, Tissierellales). A combination of RT-PCR and pyrosequencing for active bacterial composition showed that the dominant taxa i.e., Atopostipes and Tissierella, were active in fermented skate. Those dominant taxa are possibly marine lactic acid bacteria. Marine bacteria of the taxa Lactobacillales and/or Clostridia seem to be important in alkaline fermentation of skates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Oxygen and diverse nutrients influence the water kefir fermentation process.

Science.gov (United States)

Laureys, David; Aerts, Maarten; Vandamme, Peter; De Vuyst, Luc

2018-08-01

Eight water kefir fermentation series differing in the presence of oxygen, the nutrient concentration, and the nutrient source were studied during eight consecutive backslopping steps. The presence of oxygen allowed the proliferation of acetic acid bacteria, resulting in high concentrations of acetic acid, and decreased the relative abundance of Bifidobacterium aquikefiri. Low nutrient concentrations resulted in slow water kefir fermentation and high pH values, which allowed the growth of Comamonas testosteroni/thiooxydans. Further, low nutrient concentrations favored the growth of Lactobacillus hilgardii and Dekkera bruxellensis, whereas high nutrient concentrations favored the growth of Lactobacillus nagelii and Saccharomyces cerevisiae. Dried figs, dried apricots, and raisins resulted in stable water kefir fermentation. Water kefir fermentation with dried apricots resulted in the highest pH and water kefir grain growth, whereas that with raisins resulted in the lowest pH and water kefir grain growth. Further, water kefir fermentation with raisins resembled fermentations with low nutrient concentrations, that with dried apricots resembled fermentations with normal nutrient concentrations, and that with fresh figs or a mixture of yeast extract and peptone resembled fermentations with high nutrient concentrations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Treatment of biomass to obtain fermentable sugars

Science.gov (United States)

Dunson, Jr., James B.; Tucker, Melvin [Lakewood, CO; Elander, Richard [Evergreen, CO; Hennessey, Susan M [Avondale, PA

2011-04-26

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

Solid state fermentation for foods and beverages

NARCIS (Netherlands)

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

2013-01-01

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

Fermentation and storage of probiotic yoghurt from goat’s milk

Directory of Open Access Journals (Sweden)

Rajka Božanić

2002-04-01

Full Text Available Cow’s and goat’s milk supplemented with inulin were fermented withABT4 culture. The population growth of Streptococcus thermophilus,Lactobacillus acidophilus and Bifidobacterium ssp. in plain and inulinsupplemented goat’s milk during fermentation was evaluated. The survival of strains during 28 d of storage was followed in comparison with that of cow’s milk. The time required to reach the desired pH of 4.6 during fermentation was 6 h for both types of milk. At that time the proportion of viable cells of Streptococcus thermophilus, Lactobacillus acidophilus and Bifidobacterium ssp. in all fermented samples was comparable 40 : 33 : 27, respectively. During the storage viable count of streptococci and bifidobacteria have not decreased. In supplemented samples viable counts of bifidobacteria were increased and during 28th day of storage were higher for 0.6 logarithms compared to the non supplemented samples. Surviving of lactobacilli was poorer in fermented goat's milk than in fermented cow's milk during storage. The addition of inulin improved the firmness of fermented goat’s and cow’s milks products. Inulin addition partly masked the goat’s flavour of produced yoghurt. During storage the fermented goat's samples were scored better in comparison with cow's samples. Goat’s milk fermented with probiotic bacteria and fortified with inulin complies with the requirements of functional food.

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

NARCIS (Netherlands)

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

2014-01-01

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

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

NARCIS (Netherlands)

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

2014-01-01

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

Fermentation Characteristics, Tannin Contents and Ruminal Degradation of Green Tea and Black Tea By-products Ensiled at Different Temperatures

Directory of Open Access Journals (Sweden)

Makoto Kondo

2014-07-01

Full Text Available Green and black tea by-products, obtained from ready-made tea industry, were ensiled at 10°C, 20°C, and 30°C. Green tea by-product silage (GTS and black tea by-product silage (BTS were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at 10°C. The GTS stored at 20°C and 30°C showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on NH3-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and NH3-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and NH3-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin’s activity in the rumen.

Transport of the Glucosamine-Derived Browning Product Fructosazine (Polyhydroxyalkylpyrazine) Across the Human Intestinal Caco-2 Cell Monolayer: Role of the Hexose Transporters.

Science.gov (United States)

Bhattacherjee, Abhishek; Hrynets, Yuliya; Betti, Mirko

2017-06-14

The transport mechanism of fructosazine, a glucosamine self-condensation product, was investigated using a Caco-2 cell model. Fructosazine transport was assessed by measuring the bidirectional permeability coefficient across Caco-2 cells. The mechanism of transport was evaluated using phlorizin, an inhibitor of sodium-dependent glucose cotransporters (SGLT) 1 and 2, phloretin and quercetin, inhibitors of glucose transporters (GLUT) 1 and 2, transcytosis inhibitor wortmannin, and gap junction disruptor cytochalasin D. The role of hexose transporters was further studied using downregulated or overexpressed cell lines. The apparent permeability (P a,b ) of fructosazine was 1.30 ± 0.02 × 10 -6 cm/s. No significant (p > 0.05) effect was observed in fructosazine transport by adding wortmannin and cytochalasin D. The presence of phlorizin, phloretin, and quercetin decreased fructosazine transport. The downregulated GLUT cells line was unable to transport fructosazine. In human intestinal epithelial Caco-2 cells, GLUT1 or GLUT2 and SGLT are mainly responsible for fructosazine transport.

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.

Purification and fermentation characteristics of exopolysaccharide from Fomitopsis castaneus Imaz.

Science.gov (United States)

Guo, Wenkui; Chi, Yujie

2017-12-01

Short-chain fatty acids (SCFAs), which are the end products of carbohydrate fermentation in the gut, mainly contribute to energy metabolism in mammals. The amount of SCFAs produced during fermentation is an important parameter that characterizes the fermentation capacity of a system. This paper reports on the fermentation characteristics of exopolysaccharides (EPS) isolated from Fomitopsis castaneus Imaz, a wood-rot fungal species. We isolated and purified the main EPS fraction by freeze drying and DEAE-Sepharose fast flow chromatography. We then analyzed the monosaccharide composition of EPS. The isolated EPS was mainly composed of glucose, galactose, rhamnose, mannose, and arabinose. The characteristic absorption peaks of sugar esters were also detected. Fresh fecal extracts from healthy adults and children were used as fermentation substrate to simulate the human intestinal environment (anaerobic conditions at 37°C) and study the fermentation characteristics of the purified EPS. Adding the isolated EPS to the fermentation system of the simulated intestinal environment increased the SCFAs content in the fecal extract of adults and children. However, the yield of SCFAs, particularly butyric acid, in the fermentation system of fecal extract in children was higher than that in adults. Furthermore, adding exogenous lactic acid bacteria, such as Enterococcus fecalis and Enterococcus fecium, to the fermentation system effectively increased the SCFAs concentration in the model intestinal system of the children. By contrast, adding E. fecalis, Lactobacillus rhamnosus, and E. fecium increased the content of the produced SCFAs in the system of adults. Those results indicate that EPS isolated from F. castaneus Imaz was effectively fermented in the simulated intestinal environments, and the fermentation capability was enhanced by adding microbial flora. Copyright © 2017 Elsevier B.V. All rights reserved.

OXYGEN MANAGEMENT DURING ALCOHOLIC FERMENTATION

OpenAIRE

MOENNE VARGAS, MARÍA ISABE

2013-01-01

Oxygen additions are a common practice in winemaking, as oxygen has a positive effect in fermentative kinetics, biomass synthesis and improvement of color, structure and :flavor in treated wines. However, most oxygen additions are carried out heuristically through pump-over operations solely on a know-how basis, which is difficult to manage in terms of the exact quantity of oxygen transferred to the fermenting must. It is important to estímate the amount of oxygen added because...

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.

Further development of the BEKON dry fermentation process for hygienisation of substrates in the fermenter according to BioAbfV; Weiterentwicklung der BEKON-Trockenfermentation ermoeglicht die Hygienisierung der Substrate gemaess BioAbfV im Fermenter

Energy Technology Data Exchange (ETDEWEB)

Liebeneiner, Rolf; Lutz, Peter [Bekon Energy Technologies GmbH und Co. KG, Unterfoehring (Germany)

2012-11-01

In the draft amendment to the BioAbfV (BMU, 2011), temperatures and times of residue to ensure hygienisation of substrates for thermophilic fermentation were revised on the basis of EU law on animal by-products and fertilizer law and on the basis of practical experience with the directive and recent research findings on hygienisation of biomass waste. To test the process, the required thermophilic process temperature of 50 must be ensured for the totality of substrates for a minimum time of residue. The fermentation substrates are then tested for phytohygiene and epidemic hygiene. BEKON developed their patented fermenter heating system into the world's first batch dry fermentation plant for hygienisation inside the fermenter, which was commissioned in 2010 at Spiez, Switzerland. The plant was capable of ensuring the required temperature levels and substrate hygienisation standards. The advanced thermophilic BEKON dry fermentation process thus ensures reliable hygienisation of substrates already inside the fermenter, without aerobic post-treatment of fermenation residues. This simplifies process monitoring in the subsequent composting stage. (orig.) [German] Im Entwurf zur Novellierung der BioAbfV (BMU, 2011) wurden die erforderlichen Temperaturen und Verweilzeiten zur Sicherstellung der Hygienisierung der Substrate fuer die thermophile Vergaerung ueberarbeitet. Grundlage hierfuer waren unter anderem sowohl neue und geaenderte rechtlicher Vorschriften des EU-Rechts ueber die tierischen Nebenprodukte und des Duengerechts, als auch Praxiserfahrungen seit Inkrafttreten der Verordnung und neue Forschungsergebnisse zur Hygienisierung von Bioabfaellen. Die Prozesspruefung muss dabei so vorgenommen werden, dass ueber einen zusammenhaengenden Zeitraum (der sogenannten Mindestverweilzeit) die geforderte thermophile Behandlungstemperatur von mindestens 50 C auf die gesamten Substrate einwirkt. Die seuchen- und phytohygienische Unbedenklichkeit der Gaersubstrate ist dabei

MASS TRANSFER IN FERMENTATION PROCESSES

Directory of Open Access Journals (Sweden)

A. Shevchenko

2018-04-01

Full Text Available The peculiarities of anaerobic fermentation processes with the accumulation of dissolved ethyl alcohol and carbon dioxide in the culture media are considered in the article.The solubility of CO2 is limited by the state of saturation in accordance with Henry’s law. This, with all else being equal, limits the mass transfer on the interface surface of yeast cells and the liquid phase of the medium. A phenomenological model of the media restoration technologies based on the unsaturation index on СО2 is developed. It is shown that this restoration in the existing technologies of fermentation of sugar-rich media occurs, to a limited extent, in self-organized flow circuits, with variable values of temperatures and hydrostatic pressures, due to the creation of unsaturated local zones.It is shown that increasing the height of the media in isovolumetric apparatuses leads to an increase in the levels of flow circuits organization and to the improvement of the desaturation and saturation modes of the liquid phase and intensification of mass transfer processes. Among the deterministic principles of restoring the saturation possibilities of the media, there are forced variables of pressures with time pauses on their lower and upper levels. In such cases, the possibilities of short-term intensive desaturations in full media volumes, the restoration of their saturation perception of CO2, and the activation of fermentation processes are achieved. This direction is technically feasible for active industrial equipment.The cumulative effect of the action of variable pressures and temperatures corresponds to the superposition principle, but at the final stages of fermentation, the pressure and temperature values are leveled, so the restoration of the unsaturation state slows down to the level of the bacteriostatic effect. The possibility of eliminating the disadvantages of the final stage of fermentation by means of programmable variable pressures is shown

Lactobacillus paracasei CBA L74 metabolic products and fermented milk for infant formula have anti-inflammatory activity on dendritic cells in vitro and protective effects against colitis and an enteric pathogen in vivo.

Directory of Open Access Journals (Sweden)

Elena Zagato

Full Text Available The rapid expansion of commercially available fermented food products raises important safety issues particularly when infant food is concerned. In many cases, the activity of the microorganisms used for fermentation as well as what will be the immunological outcome of fermented food intake is not known. In this manuscript we used complex in vitro, ex-vivo and in vivo systems to study the immunomodulatory properties of probiotic-fermented products (culture supernatant and fermented milk without live bacteria to be used in infant formula. We found in vitro and ex-vivo that fermented products of Lactobacillus paracasei CBA L74 act via the inhibition of proinflammatory cytokine release leaving anti-inflammatory cytokines either unaffected or even increased in response to Salmonella typhimurium. These activities are not dependent on the inactivated bacteria but to metabolic products released during the fermentation process. We also show that our in vitro systems are predictive of an in vivo efficacy by the fermented products. Indeed CBA L74 fermented products (both culture medium and fermented milk could protect against colitis and against an enteric pathogen infection (Salmonella typhimurium. Hence we found that fermented products can act via the inhibition of immune cell inflammation and can protect the host from pathobionts and enteric pathogens. These results open new perspectives in infant nutrition and suggest that L. paracasei CBA L74 fermented formula can provide immune benefits to formula-fed infants, without carrying live bacteria that may be potentially dangerous to an immature infant immune system.

Invited review: Fermented milk as antihypertensive functional food.

Science.gov (United States)

Beltrán-Barrientos, L M; Hernández-Mendoza, A; Torres-Llanez, M J; González-Córdova, A F; Vallejo-Córdoba, B

2016-06-01

Over the past decade, interest has risen in fermented dairy foods that promote health and could prevent diseases such as hypertension. This biological effect has mainly been attributed to bioactive peptides encrypted within dairy proteins that can be released during fermentation with specific lactic acid bacteria or during gastrointestinal digestion. The most studied bioactive peptides derived from dairy proteins are antihypertensive peptides; however, a need exists to review the different studies dealing with the evaluation of antihypertensive fermented milk before a health claim may be associated with the product. Thus, the objective of this overview was to present available information related to the evaluation of fermented milk containing antihypertensive peptides by in vitro and in vivo studies, which are required before a fermented functional dairy product may be introduced to the market. Although commercial fermented milks with antihypertensive effects exist, these are scarce and most are based on Lactobacillus helveticus. Thus, a great opportunity is available for the development of functional dairy products with new lactic acid bacteria that support heart health through blood pressure- and heart rate-lowering effects. Hence, the consumer may be willing to pay a premium for foods with important functional benefits. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Kombucha tea fermentation: Microbial and biochemical dynamics.

Science.gov (United States)

Chakravorty, Somnath; Bhattacharya, Semantee; Chatzinotas, Antonis; Chakraborty, Writachit; Bhattacharya, Debanjana; Gachhui, Ratan

2016-03-02

Kombucha tea, a non-alcoholic beverage, is acquiring significant interest due to its claimed beneficial properties. The microbial community of Kombucha tea consists of bacteria and yeast which thrive in two mutually non-exclusive compartments: the soup or the beverage and the biofilm floating on it. The microbial community and the biochemical properties of the beverage have so far mostly been described in separate studies. This, however, may prevent understanding the causal links between the microbial communities and the beneficial properties of Kombucha tea. Moreover, an extensive study into the microbial and biochemical dynamics has also been missing. In this study, we thus explored the structure and dynamics of the microbial community along with the biochemical properties of Kombucha tea at different time points up to 21 days of fermentation. We hypothesized that several biochemical properties will change during the course of fermentation along with the shifts in the yeast and bacterial communities. The yeast community of the biofilm did not show much variation over time and was dominated by Candida sp. (73.5-83%). The soup however, showed a significant shift in dominance from Candida sp. to Lachancea sp. on the 7th day of fermentation. This is the first report showing Candida as the most dominating yeast genus during Kombucha fermentation. Komagateibacter was identified as the single largest bacterial genus present in both the biofilm and the soup (~50%). The bacterial diversity was higher in the soup than in the biofilm with a peak on the seventh day of fermentation. The biochemical properties changed with the progression of the fermentation, i.e., beneficial properties of the beverage such as the radical scavenging ability increased significantly with a maximum increase at day 7. We further observed a significantly higher D-saccharic acid-1,4-lactone content and caffeine degradation property compared to previously described Kombucha tea fermentations. Our

Fermented foods, neuroticism, and social anxiety: An interaction model.

Science.gov (United States)

Hilimire, Matthew R; DeVylder, Jordan E; Forestell, Catherine A

2015-08-15

Animal models and clinical trials in humans suggest that probiotics can have an anxiolytic effect. However, no studies have examined the relationship between probiotics and social anxiety. Here we employ a cross-sectional approach to determine whether consumption of fermented foods likely to contain probiotics interacts with neuroticism to predict social anxiety symptoms. A sample of young adults (N=710, 445 female) completed self-report measures of fermented food consumption, neuroticism, and social anxiety. An interaction model, controlling for demographics, general consumption of healthful foods, and exercise frequency, showed that exercise frequency, neuroticism, and fermented food consumption significantly and independently predicted social anxiety. Moreover, fermented food consumption also interacted with neuroticism in predicting social anxiety. Specifically, for those high in neuroticism, higher frequency of fermented food consumption was associated with fewer symptoms of social anxiety. Taken together with previous studies, the results suggest that fermented foods that contain probiotics may have a protective effect against social anxiety symptoms for those at higher genetic risk, as indexed by trait neuroticism. While additional research is necessary to determine the direction of causality, these results suggest that consumption of fermented foods that contain probiotics may serve as a low-risk intervention for reducing social anxiety. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The impact of yeast fermentation on dough matrix properties.

Science.gov (United States)

Rezaei, Mohammad N; Jayaram, Vinay B; Verstrepen, Kevin J; Courtin, Christophe M

2016-08-01

Most studies on dough properties are performed on yeastless dough to exclude the complicating, time-dependent effect of yeast. Baker's yeast, however, impacts dough matrix properties during fermentation, probably through the production of primary (CO2 and ethanol) and secondary (glycerol, acetic acid and succinic acid) metabolites. The aim of this study is to obtain a better understanding of the changes in yeasted dough behavior introduced by fermentation, by investigating the impact of yeast fermentation on Farinograph dough consistency, dough spread, Kieffer rig dough extensibility and gluten agglomeration behavior in a fermented dough-batter gluten starch separation system. Results show that fermentation leads to a dough with less flow and lower extensibility that breaks more easily under stress and strain. The dough showed less elastic and more plastic deformation behavior. Gluten agglomerates were smaller for yeasted dough than for the unyeasted control. These changes probably have to be attributed to metabolites generated during fermentation. Indeed, organic acids and also ethanol in concentrations produced by yeast were previously shown to have similar effects in yeastless dough. These findings imply the high importance of yeast fermentation metabolites on dough matrix properties in industrial bread production. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Method for anaerobic fermentation and biogas production

DEFF Research Database (Denmark)

2013-01-01

The present invention relates to a method for biomass processing, anaerobic fermentation of the processed biomass, and the production biogas. In particular, the invention relates to a system and method for generating biogas from anaerobic fermentation of processed organic material that comprises...

Fermentation: From Sensory Experience to Conceptual Understanding

Science.gov (United States)

Moore, Eugene B.

1977-01-01

Presented is a laboratory exercise that utilizes the natural yeast carbonation method of making homemade root beer to study fermentation and the effect of variables upon the fermentation process. There are photographs, a sample data sheet, and procedural hints included. (Author/MA)

Characterization of antimicrobial activity in Kombucha fermentation

NARCIS (Netherlands)

Sreeramulu, G.; Zhu, Y.; Knol, W.

2001-01-01

Fermented tea drink, Kombucha, can inhibit the growth of Shigella sonnei, Escherichia coli, Salmonella enteritidis and Salmonella typhimurium. Several metabolites were analyzed every two days during a 14-day Kombucha fermentation. Levels of acetic acid and gluconic acid were found to increase with

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.

Production of Star Fruit Alcoholic Fermented Beverage.

Science.gov (United States)

Valim, Flávia de Paula; Aguiar-Oliveira, Elizama; Kamimura, Eliana Setsuko; Alves, Vanessa Dias; Maldonado, Rafael Resende

2016-12-01

Star fruit ( Averrhoa carambola ) is a nutritious tropical fruit. The aim of this study was to evaluate the production of a star fruit alcoholic fermented beverage utilizing a lyophilized commercial yeast ( Saccharomyces cerevisiae ). The study was conducted utilizing a 2 3 central composite design and the best conditions for the production were: initial soluble solids between 23.8 and 25 °Brix (g 100 g -1 ), initial pH between 4.8 and 5.0 and initial concentration of yeast between 1.6 and 2.5 g L -1 . These conditions yielded a fermented drink with an alcohol content of 11.15 °GL (L 100 L -1 ), pH of 4.13-4.22, final yeast concentration of 89 g L -1 and fermented yield from 82 to 94 %. The fermented drink also presented low levels of total and volatile acidities.

Traditional fermented food and beverages for improved livelihoods

OpenAIRE

Mejia, Danilo; Marshall, Elaine

2015-01-01

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

The microbial diversity of traditional spontaneously fermented lambic beer.

Science.gov (United States)

Spitaels, Freek; Wieme, Anneleen D; Janssens, Maarten; Aerts, Maarten; Daniel, Heide-Marie; Van Landschoot, Anita; De Vuyst, Luc; Vandamme, Peter

2014-01-01

Lambic sour beers are the products of a spontaneous fermentation that lasts for one to three years before bottling. The present study determined the microbiota involved in the fermentation of lambic beers by sampling two fermentation batches during two years in the most traditional lambic brewery of Belgium, using culture-dependent and culture-independent methods. From 14 samples per fermentation, over 2000 bacterial and yeast isolates were obtained and identified. Although minor variations in the microbiota between casks and batches and a considerable species diversity were found, a characteristic microbial succession was identified. This succession started with a dominance of Enterobacteriaceae in the first month, which were replaced at 2 months by Pediococcus damnosus and Saccharomyces spp., the latter being replaced by Dekkera bruxellensis at 6 months fermentation duration.

The microbial diversity of traditional spontaneously fermented lambic beer.

Directory of Open Access Journals (Sweden)

Freek Spitaels

Full Text Available Lambic sour beers are the products of a spontaneous fermentation that lasts for one to three years before bottling. The present study determined the microbiota involved in the fermentation of lambic beers by sampling two fermentation batches during two years in the most traditional lambic brewery of Belgium, using culture-dependent and culture-independent methods. From 14 samples per fermentation, over 2000 bacterial and yeast isolates were obtained and identified. Although minor variations in the microbiota between casks and batches and a considerable species diversity were found, a characteristic microbial succession was identified. This succession started with a dominance of Enterobacteriaceae in the first month, which were replaced at 2 months by Pediococcus damnosus and Saccharomyces spp., the latter being replaced by Dekkera bruxellensis at 6 months fermentation duration.

Potential of solid state fermentation for production of ergot alkaloids

OpenAIRE

Trejo Hernandez, M.R.; Raimbault, Maurice; Roussos, Sevastianos; Lonsane, B.K.

1992-01-01

Production of total ergot alkaloids by #Claviceps fusiformis$ in solid state fermentation was 3.9 times higher compared to that in submerged fermentation. Production was equal in the case of #Claviceps purpurea$ but the spectra of alkaloids were advantageous with the use of solid state fermentation. The data establish potential of solid state fermentation which was not explored earlier for production of ergot alkaloids. (Résumé d'auteur)

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.

Characteristics of Milk Fermented by Streptococcus thermophilus MGA45-4 and the Profiles of Associated Volatile Compounds during Fermentation and Storage.

Science.gov (United States)

Dan, Tong; Jin, Rulin; Ren, Weiyi; Li, Ting; Chen, Haiyan; Sun, Tiansong

2018-04-11

The lactic acid bacterium Streptococcus thermophilus is a major starter culture for the production of dairy products. In this study, the physiochemical characteristics of milk fermented by the MGA45-4 isolate of S. thermophilus were analyzed. Our data indicate that milk fermented using S. thermophilus MGA45-4 maintained a high viable cell count (8.86 log10 colony-forming units/mL), and a relatively high pH (4.4), viscosity (834.33 mPa·s), and water holding capacity (40.85%) during 14 days of storage. By analyzing the volatile compound profile using solid-phase microextraction and gas chromatography/mass spectrometry, we identified 73 volatile compounds in the fermented milk product, including five carboxylic acids, 21 aldehydes, 13 ketones, 16 alcohols, five esters, and 13 aromatic carbohydrates. According to the odor activity values, 11 of these volatile compounds were found to play a key role in producing the characteristic flavor of fermented milk, particularly octanal, nonanal, hexanal, 2,3-butanedione, and 1-octen-3-ol, which had the highest odor activity values among all compounds analyzed. These findings thus provide more insights in the chemical/molecular characteristics of milk fermented using S. thermophilus , which may provide a basis for improving dairy product flavor/odor during the process of fermentation and storage.

Effect of controlled fermentation on the oligosaccharides content of ...

African Journals Online (AJOL)

For oloyin beans slurry, fermentation for 72 h also resulted in significant reduction in the raffinose content when fermented with L. plantarum, L. fermentum and P. acidilactici with 53.68, 73.17 and 64.02% reductions, respectively. Sucrose content showed significant increase for both beans slurry fermented for 72 h with all of ...

Quality of fermented cassava flour processed into placali | Koko ...

African Journals Online (AJOL)

Fermented cassava flour was obtained from Yace variety. Cassava roots were washed, peeled and ground. After adding cassava inoculums at 8% (m/m), the pulp was allowed to ferment for 72 hours at ambient temperature. The fermented dough was removed, squeezed and oven-dried for 48 hours at 55 °C. The dried ...

Nutritional and amino acid analysis of raw, partially fermented and ...

African Journals Online (AJOL)

African Journal of Food, Agriculture, Nutrition and Development ... The nutritional and amino acid analysis of raw and fermented seeds of Parkia ... between 4.27 and 8.33 % for the fully fermented and the partially fermented seeds, respectively.

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)

Rheology of corn stover slurries during fermentation to ethanol

Science.gov (United States)

Ghosh, Sanchari; Epps, Brenden; Lynd, Lee

2017-11-01

In typical processes that convert cellulosic biomass into ethanol fuel, solubilization of the biomass is carried out by saccharolytic enzymes; however, these enzymes require an expensive pretreatment step to make the biomass accessible for solubilization (and subsequent fermentation). We have proposed a potentially-less-expensive approach using the bacterium Clostridium thermocellum, which can initiate fermentation without pretreatment. Moreover, we have proposed a ``cotreatment'' process, in which fermentation and mechanical milling occur alternately so as to achieve the highest ethanol yield for the least milling energy input. In order to inform the energetic requirements of cotreatment, we experimentally characterized the rheological properties of corn stover slurries at various stages of fermentation. Results show that a corn stover slurry is a yield stress fluid, with shear thinning behavior well described by a power law model. Viscosity decreases dramatically upon fermentation, controlling for variables such as solids concentration and particle size distribution. To the authors' knowledge, this is the first study to characterize the changes in the physical properties of biomass during fermentation by a thermophilic bacterium.

Influence of spontaneous fermentation on some quality ...

African Journals Online (AJOL)

Sensory evaluation indicated that the techniques of nixtamalization, fermentation and cowpea fortification used for the processing of the products did not influence their acceptability by the panel. Nixtamalized maize can therefore be subjected to spontaneous fermentation with cowpea fortification to enhance the functional, ...

Effects of fermentation by Saccharomyces cerevisiae and ...

African Journals Online (AJOL)

yassine

2013-02-13

Feb 13, 2013 ... Effect of Saccharomyces cerevisiae fermentation on the ... beetroot, fermentation, Saccharomyces cerevisiae, betalain compounds. ... by Saccharomyces cerevisiae strains (González et al., .... Both red and yellow pigments were influenced during S. .... in beverages such as white wine, grape fruit, and green.

Microbial fermented tea - a potential source of natural food preservatives

NARCIS (Netherlands)

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

2008-01-01

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

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.

EFFECT OF TEMPERATURE ON THE PROCESS OF BEER PRIMARY FERMENTATION

Directory of Open Access Journals (Sweden)

Miriam Solgajová

2013-02-01

Full Text Available Beer is a very popular and widespread drink worldwide. Beer may be defined as a foamy alcoholic drink aerated by carbon dioxide that is formed during fermentation. Sensorial and analytical character of beer is mainly formed during process of primary fermentation. Our work has monitored the influence of temperature of fermentation substrate on the process of primary fermentation during beer production. Obtained values of temperature and apparent extract out of four brews of 10% light hopped wort has been recorded, during the process of primary fermentation carried out in mini brewery of SPU. We have compared our results with theoretical values of primary fermentation process commonly achieved in conditions of industrial breweries. It was found out that our results differ in some ways, moreover they exceed theoretically given values which was caused due to different construction of mini brewery fermentation tank in comparison with industrial brewery technologies. Beer produced in mini brewery of SPU showed in sensorial tests very good quality without any strange odour and any strange taste.

Continuous energy recovery and nutrients removal from molasses wastewater by synergistic system of dark fermentation and algal culture under various fermentation types.

Science.gov (United States)

Ren, Hong-Yu; Kong, Fanying; Ma, Jun; Zhao, Lei; Xie, Guo-Jun; Xing, Defeng; Guo, Wan-Qian; Liu, Bing-Feng; Ren, Nan-Qi

2018-03-01

Synergistic system of dark fermentation and algal culture was initially operated at batch mode to investigate the energy production and nutrients removal from molasses wastewater in butyrate-type, ethanol-type and propionate-type fermentations. Butyrate-type fermentation was the most appropriate fermentation type for the synergistic system and exhibited the accumulative hydrogen volume of 658.3 mL L -1 and hydrogen yield of 131.7 mL g -1 COD. By-products from dark fermentation (mainly acetate and butyrate) were further used to cultivate oleaginous microalgae. The maximum algal biomass and lipid content reached 1.01 g L -1 and 38.5%, respectively. In continuous operation, the synergistic system was stable and efficient, and energy production increased from 8.77 kJ L -1  d -1 (dark fermentation) to 17.3 kJ L -1  d -1 (synergistic system). Total COD, TN and TP removal efficiencies in the synergistic system reached 91.1%, 89.1% and 85.7%, respectively. This study shows the potential of the synergistic system in energy recovery and wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Demonstration-Scale High-Cell-Density Fermentation of Pichia pastoris.

Science.gov (United States)

Liu, Wan-Cang; Zhu, Ping

2018-01-01

Pichia pastoris has been one of the most successful heterologous overexpression systems in generating proteins for large-scale production through high-cell-density fermentation. However, optimizing conditions of the large-scale high-cell-density fermentation for biochemistry and industrialization is usually a laborious and time-consuming process. Furthermore, it is often difficult to produce authentic proteins in large quantities, which is a major obstacle for functional and structural features analysis and industrial application. For these reasons, we have developed a protocol for efficient demonstration-scale high-cell-density fermentation of P. pastoris, which employs a new methanol-feeding strategy-biomass-stat strategy and a strategy of increased air pressure instead of pure oxygen supplement. The protocol included three typical stages of glycerol batch fermentation (initial culture phase), glycerol fed-batch fermentation (biomass accumulation phase), and methanol fed-batch fermentation (induction phase), which allows direct online-monitoring of fermentation conditions, including broth pH, temperature, DO, anti-foam generation, and feeding of glycerol and methanol. Using this protocol, production of the recombinant β-xylosidase of Lentinula edodes origin in 1000-L scale fermentation can be up to ~900 mg/L or 9.4 mg/g cells (dry cell weight, intracellular expression), with the specific production rate and average specific production of 0.1 mg/g/h and 0.081 mg/g/h, respectively. The methodology described in this protocol can be easily transferred to other systems, and eligible to scale up for a large number of proteins used in either the scientific studies or commercial purposes.

Optimization of a fed-batch fermentation process for production of ...

African Journals Online (AJOL)

user

2011-02-28

Feb 28, 2011 ... fermentation. Overall, this study suggested that fed-batch fermentation can be successfully used to ... catalysts that catalyze their own synthesis. Enzymes are .... shows the amount of biomass (g l−1) in the fermentation broth of ...

Insulin binding and stimulation of hexose and amino acid transport by normal and receptor-defective human fibroblasts

International Nuclear Information System (INIS)

Longo, N.; Nagata, N.; Danner, D.; Priest, J.; Elsas, L.

1986-01-01

The authors analyzed insulin receptors in cells cultured from a sibship of related parents who had two offspring with severe insulin resistance (Leprechaunism). 124 I-Insulin (1 ng/ml) binding to skin fibroblasts from the proband, mother, and father was 9, 60 and 62% of control cells, respectively, at equilibrium, Non-linear regression analysis, utilizing a two receptors model, of curvilinear Scatchard plots indicated a reduced number of high-affinity binding sites in both parents. Influx of L-Proline (System A), L-Serine (ASC) and L-Leucine (L) was similar in control and mutant cells. Similarly, during the depletion of intracellular amino acid pools, there was a release from transinhibition for System A and a decrease of transstimulation of Systems ASC and L in both cell lines. Surprisingly, insulin augmented, normally, A system influx with an ED 50 = 70 ng/ml at 24 0 C and 7 ng/ml at 37 0 C. By contrast insulin failed to simulated 3-0-methyl-D-glucose influx into the proband's cells, while normal cells were stimulated 30% with an ED 50 of 6 ng/ml. These results indicate that defective high-affinity insulin binding is inherited as an autosomal recessive trait; that general membrane functions are intact; that insulin regulates A system amino acid and hexose transport by two different mechanisms; and, that the latter mechanism is impaired by this family's receptor mutation

Butanol-acetone fermentation. Bibliographic synthesis and current trends

Energy Technology Data Exchange (ETDEWEB)

Marchal, R. (Institut Francais du Petrole, Rueil-Malmaison (France))

This article gives a synthesis of what is known about butyl-acetone fermentation from both the microbiological and technological standpoints. Different aspects of the metabolism of the microorganism used and of how it is regulated are considered. The performances of fermentation on traditional substrates (cornmeal or molasses) are compared with those recently obtained using Jerusalem artichokes at Institut Francais du Petrole as part of a new project on this fermentation for the purpose of producing substitute fuel.

Use of biomass energy. Saccharification of raw starch and ethanol fermentation

Energy Technology Data Exchange (ETDEWEB)

Ueda, S

1982-01-01

Raw starch was saccharified under acidic condition of pH 3.5 using black-koji amylase, and the resultant saccharidies were fermented to give ethanol in succession. White polished rice flour was fermented at 30 degrees C during the period of 7 to 10 days to give ethanol. Semi-continuous ethanol fermentation was carried out using corn starch and cassava starch. Batch ethanol fermentation was also carried out using cassava or sweet potato. Sweet potato was fermented using Rhizopus gluco-amylase. 11 references.

Membrane gas sensors for fermentation monitoring

Energy Technology Data Exchange (ETDEWEB)

Mandenius, C F

1987-12-01

Results of a study on membrane gas sensors are presented to show their general applicability to fermentation monitoring of volatiles, such as alcohols, organic acids and aldehydes under various process and reactor conditions. Permeable silicone (Noax AB) and teflon (fluorcarbon AB) are tested as material for a gas sensor. The silicone tubing method is mainly used and ethanolic fermentation is performed in the study. Investigation is made to determine the dependence of the sensitivity of the sensors on the temperature, pH, concentration and other properties of fermentation liquid. The effect of temperature on the ethanol response is investigated in the temperature range of 7-50/sup 0/C to reveal that the response time decreases while the sensor's sensitivity increases with an increasing temperature. Comparison among methanol, ethyl acetate, acetaldehyde and ethanol is made with respect to the effect of their concentration on the sensitivity of a sensor. Results of a three-month measurement with the sensor immersed in fermentation liquid are compared with those of GC analysis to investigate the correlation between the sensor's sensitivity and GC analysis data. (11 figs, 17 refs)