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    We will mail you new results for this query: keywords==Fermentation
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Effect of fermentation on content, molecule weight distribution and viscosity of β-glucans in oat sourdough
Lu, Jun ; Shan, Lingke ; Xie, Yiting ; Min, Fangfang ; Gao, Jinyan ; Guo, Laichun ; Ren, Changzhong ; Yuan, Juanli ; Gilissen, Luud ; Chen, Hongbing - \ 2018
International Journal of Food Science and Technology (2018). - ISSN 0950-5423
Fermentation - Lactobacillus plantarum - Oat β-glucan - Sourdough - Viscosity

This study investigated the effect of fermentation on the physicochemical properties of β-glucans in oat sourdough. Sourdoughs were produced from oat using homo-fermentative lactic acid bacteria, Lactobacillus plantarum 22134. The contents of total β-glucan and soluble β-glucan, the molecular weight (MW) of β-glucan and the viscosity of the extracted β-glucans were determined at 0, 4, 8, 10 and 12 h of fermentation. The total β-glucan content decreased from 4.89% to 4.23% after 12 h of fermentation. The soluble β-glucan concentration increased from 1.89% to 2.18% and then decreased to 1.97% after 8 h of fermentation. The content of β-glucans with MW > 105 decreased from 0 to 4 h of fermentation, followed by an increase and then a decrease after 8 h. The oat sourdough fermented for 8 h had high viscosity, which could be more beneficial for health and bread texture quality, especially for gluten-free breads. International Journal of Food Science and Technology

Aroma formation during cheese ripening is best resembled by Lactococcus lactis retentostat cultures
Mastrigt, Oscar van; Gallegos Tejeda, Diego ; Kristensen, Mette N. ; Abee, Tjakko ; Smid, Eddy J. - \ 2018
Microbial Cell Factories 17 (2018)1. - ISSN 1475-2859
Fermentation - Metabolism - VOC - Zero growth

Background: Cheese ripening is a complex, time consuming and expensive process, which involves the generation of precursors from carbohydrates, proteins and fats and their subsequent conversion into a wide range of compounds responsible for the flavour and texture of the cheese. This study aims to investigate production of cheese aroma compounds outside the cheese matrix that could be applied for instance as food supplements in dairy or non-dairy products. Results: In this study, aroma formation by a dairy Lactococcus lactis was analysed as a function of the growth medium [milk, hydrolysed micellar casein isolate (MCI) and chemically defined medium (CDM)] and the cultivation conditions (batch culture, retentostat culture and a milli-cheese model system). In the retentostat cultures, the nutrient supply was severely restricted resulting in low growth rates (~ 0.001 h-1), thereby mimicking cheese ripening conditions in which nutrients are scarce and bacteria hardly grow. In total 82 volatile organic compounds were produced by the bacteria. Despite the use of a chemically defined medium, retentostat cultures had the biggest qualitative overlap in aroma production with the milli-cheese model system (36 out of 54 compounds). In the retentostat cultures, 52 known cheese compounds were produced and several important cheese aroma compounds and/or compounds with a buttery or cheese-like aroma increased in retentostat cultures compared to batch cultures and milli-cheeses, such as esters, methyl ketones, diketones and unsaturated ketones. In cultures on CDM and MCI, free fatty acids and their corresponding degradation products were underrepresented compared to what was found in the milli-cheeses. Addition of a mixture of free fatty acids to CDM and MCI could help to enhance flavour formation in these media, thereby even better resembling flavour formation in cheese. Conclusions: This study demonstrates that retentostat cultivation is the preferred method to produce cheese flavours outside the cheese matrix by mimicking the slow growth of bacteria during cheese ripening.

Microencapsulated Starter Culture During Yoghurt Manufacturing, Effect on Technological Features
Prisco, Annachiara de; Valenberg, Hein J.F. van; Fogliano, Vincenzo ; Mauriello, Gianluigi - \ 2017
Food Bioprocess Technology 10 (2017)10. - ISSN 1935-5130 - p. 1767 - 1777.
Cell physiology - Fermentation - Microencapsulation - Probiotic - Volatile metabolites

The potential of living cell microencapsulation in sustaining cells’ viability, functionality and targeted release in gastrointestinal tract is relatively well documented. Differently, the effects exerted by the capsules on cell metabolic activities during fermentation of a food matrix as well as on cell physiology are poorly addressed. This paper aimed at studying the effects of chitosan-alginate capsules (matrix and core-shell) on metabolic activities of Streptococcus thermophilus and probiotic Lactobacillus delbrueckii during milk fermentation for yoghurt production. This food system has been used to monitor growth, acidification kinetics and strain proteolytic activity. Bacterial viability has been monitored during yoghurt storage at 4 °C for 28 days and an in vitro digestion to evaluate the protective effect exerted by the capsules. Furthermore, production of volatile metabolites associated with starter culture activity was monitored by headspace solid-phase microextraction-GC/MS to explore possible influence of microenvironment on cell metabolism. Results indicate that both kinds of capsules influenced at different extent cell functionalities (growth, acidification and proteolysis), while they improve cell viability during yoghurt storage and simulated gastrointestinal passage. The volatile pattern revealed that capsules influenced their production in yoghurt: 12 out of 28 volatiles recovered in yoghurt fermented by free and encapsulated starters had significantly different concentration. However, concentration of the main aroma constituents (e.g. acetaldehyde, diacetyl, acetoin) was not significantly affected. Due to the leakage of bacteria from microcapsules during fermentation, the final product resulted in co-existing of free and still encapsulated cells, with the main advantage of an increased viability during yoghurt storage and simulated digestion of the encapsulated counterpart.

Streptococcus caviae sp. nov., isolated from Guinea pig faecal samples
Palakawong Na Ayudthaya, Susakul ; Hilderink, Loes J. ; Oost, John van der; Vos, Willem M. de; Plugge, Caroline M. - \ 2017
International Journal of Systematic and Evolutionary Microbiology 67 (2017)5. - ISSN 1466-5026 - p. 1551 - 1556.
Cellobiose - Dried grass - Fermentation - Inulin - Lactic acid - Streptococcus

A novel cellobiose-degrading and lactate-producing bacterium, strain Cavy grass 6T, was isolated from faecal samples of guinea pigs (Cavia porcellus). Cells of the strain were ovalshaped, non-motile, non-spore-forming, Gram-stain-positive and facultatively anaerobic. The strain gr at 25–40 °C (optimum 37 °C) and pH 4.5–9.5 (optimum 8.0). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Cavy grass 6T belongs to the genus Streptococcus with its closest relative being Streptococcus devriesei CCUG 47155T with only 96.5% similarity. Comparing strain Cavy grass 6T and Streptococcus devriesei CCUG 47155T, average nucleotide identity and level of digital DNA–DNA hybridization dDDH were only 86.9 and 33.3%, respectively. Housekeeping genes groEL and gyrA were different between strain Cavy grass 6T and other streptococci. The G+C content of strain Cavy grass 6T was 42.6±0.3 mol%. The major (>10%) cellular fatty acids of strain Cavy grass 6T were C16:0, C20: 1ω9c and summed feature 8 (C18: 1ω7c and/or C18: 1ω6c). Strain Cavy grass 6T ferment a range of plant mono- and disaccharides as well as polymeric carbohydrates, including cellobiose, dulcitol, D-glucose, maltose, raffinose, sucrose, L-sorbose, trehalose, inulin and dried grass extract, to lactate, formate, acetate and ethanol. Based on phylogenetic and physiological characteristics, Cavy grass 6T can be distinguished from other members of the genus Streptococcus. Therefore, a novel species of the genus Streptococcus, family Streptococcaceae, order Lactobacillales is proposed, Streptococcus caviae sp. nov. (type strain Cavy grass 6T=TISTR 2371T=DSM 102819T).

A novel millet-based probiotic fermented food for the developing world
Stefano, Elisa Di; White, Jessica ; Seney, Shannon ; Hekmat, Sharareh ; McDowell, Tim ; Sumarah, Mark ; Reid, Gregor - \ 2017
Nutrients 9 (2017)5. - ISSN 2072-6643
Cereal - Fermentation - Millet - Probiotic - Sub-Saharan Africa - Yogurt

Probiotic yogurt, comprised of a Fiti sachet containing Lactobacillus rhamnosus GR-1 and Streptococcus thermophilus C106, has been used in the developing world, notably Africa, to alleviate malnutrition and disease. In sub-Saharan African countries, fermentation of cereals such as millet, is culturally significant. The aim of this study was to investigate the fermentation capability of millet when one gram of the Fiti sachet consortium was added. An increase of 1.8 and 1.4 log CFU/mL was observed for S. thermophilus C106 and L. rhamnosus GR-1 when grown in 8% millet in water. Single cultures of L. rhamnosus GR-1 showed the highest _max when grown in the presence of dextrose, galactose and fructose. Single cultures of S. thermophilus C106 showed the highest _max when grown in the presence of sucrose and lactose. All tested recipes reached viable counts of the probiotic bacteria, with counts greater than 106 colony-forming units (CFU)/mL. Notably, a number of organic acids were quantified, in particular phytic acid, which was shown to decrease when fermentation time increased, thereby improving the bioavailability of specific micronutrients. Millet fermented in milk proved to be the most favorable, according to a sensory evaluation. In conclusion, this study has shown that sachets being provided to African communities to produce fermented milk, can also be used to produce fermented millet. This provides an option for when milk supplies are short, or if communities wish to utilize the nutrient-rich qualities of locally-grown millet.

In-situ carboxylate recovery and simultaneous pH control with tailor-configured bipolar membrane electrodialysis during continuous mixed culture fermentation
Arslan, D. ; Zhang, Y. ; Steinbusch, K.J.J. ; Diels, L. ; Hamelers, Hubertus V.M. ; Buisman, C.J.N. ; Wever, H. de - \ 2017
Separation and Purification Technology 175 (2017). - ISSN 1383-5866 - p. 27 - 35.
Bipolar membrane - Electrodialysis - Fermentation - ISPR - Short chain carboxylates

Anaerobic fermentation of organic waste streams by mixed culture generates a mixture of short chain carboxylic acids. To avoid inhibitory effects of the acids or their consumption in internal conversion reactions in the mixed culture environment, in-situ recovery of acids can be beneficial. In this study, electrodialysis with bipolar membranes (EDBM) was applied to a mixed culture fermentation on organic waste streams using a novel EDBM stack with “direct contact” operation mode. We could demonstrate simultaneous recovery of carboxylates from the fermenter by the EDBM stack while in-situ generation and transport of hydroxyl ions to the fermenter allowed direct pH control. Experiments showed productivity increase after EDBM coupling to the fermenter, and complete elimination of external base consumption. It was also observed that EDBM was able to drive the mixed culture fermentation towards acetate and propionate type of carboxylates.

Effects of pectin on fermentation characteristics, carbohydrate utilization, and microbial community composition in the gastrointestinal tract of weaning pigs
Tian, Lingmin ; Bruggeman, Geert ; Berg, Marco van den; Borewicz, Klaudyna ; Scheurink, Anton J.W. ; Bruininx, Erik ; Vos, Paul de; Smidt, Hauke ; Schols, Henk A. ; Gruppen, Harry - \ 2017
Molecular Nutrition & Food Research 61 (2017)1. - ISSN 1613-4125
Autoclave soybean meal - Dietary fiber - Digestibility - Fermentation - Microbiota composition

Scope: We aimed to investigate the effects of three different soluble pectins on the digestion of other consumed carbohydrates, and the consequent alterations of microbiota composition and SCFA levels in the intestine of pigs. Methods and results: Piglets were fed a low-methyl esterified pectin enriched diet (LMP), a high-methyl esterified pectin enriched diet (HMP), a hydrothermal treated soybean meal enriched diet (aSBM) or a control diet (CONT). LMP significantly decreased the ileal digestibility of starch resulting in more starch fermentation in the proximal colon. In the ileum, low-methyl esterified pectin present was more efficiently fermented by the microbiota than high-methyl esterified pectin present which was mainly fermented by the microbiota in the proximal colon. Treated soybean meal was mainly fermented in the proximal colon and shifted the fermentation of cereal dietary fiber to more distal parts, resulting in high SCFA levels in the mid colon. LMP, HMP, and aSBM decreased the relative abundance of the genus Lactobacillus and increased that of Prevotella in the colon. Conclusion: The LMP, HMP, and aSBM, differently affected the digestion processes compared to the control diet and shaped the colonic microbiota from a Lactobacillus-dominating flora to a Prevotella-dominating community, with potential health-promoting effects.

Production of L(+)-lactic acid from acid pretreated sugarcane bagasse using Bacillus coagulans DSM2314 in a simultaneous saccharification and fermentation strategy
Pol, Edwin C. van der; Eggink, Gerrit ; Weusthuis, Ruud A. - \ 2016
Biotechnology for Biofuels 9 (2016). - ISSN 1754-6834 - 12 p.
Bagasse - Enzymatic hydrolysis - Fermentation - Lactic acid - Lignocellulose - Simultaneous saccharification and fermentation (SSF)

Background: Sugars derived from lignocellulose-rich sugarcane bagasse can be used as feedstock for production of L(+)-lactic acid, a precursor for renewable bioplastics. In our research, acid-pretreated bagasse was hydrolysed with the enzyme cocktail GC220 and fermented by the moderate thermophilic bacterium Bacillus coagulans DSM2314. Saccharification and fermentation were performed simultaneously (SSF), adding acid-pretreated bagasse either in one batch or in two stages. SSF was performed at low enzyme dosages of 10.5-15.8 FPU/g DW bagasse. Results: The first batch SSF resulted in an average productivity of 0.78 g/l/h, which is not sufficient to compete with lactic acid production processes using high-grade sugars. Addition of 1 g/l furfural to precultures can increase B. coagulans resistance towards by-products present in pretreated lignocellulose. Using furfural-containing precultures, productivity increased to 0.92 g/l/h, with a total lactic acid production of 91.7 g in a 1-l reactor containing 20% W/W DW bagasse. To increase sugar concentrations, bagasse was solubilized with a liquid fraction, obtained directly after acid pretreatment. Solubilizing the bagasse fibres with water increased the average productivity to 1.14 g/l/h, with a total lactic acid production of 84.2 g in a 1-l reactor. Addition of bagasse in two stages reduced viscosity during SSF, resulting in an average productivity in the first 23 h of 2.54 g/l/h, similar to productivities obtained in fermentations using high-grade sugars. Due to fast accumulation of lactic acid, enzyme activity was repressed during two-stage SSF, resulting in a decrease in productivity and a slightly lower total lactic acid production of 75.6 g. Conclusions: In this study, it is shown that an adequate production of lactic acid from lignocellulose was successfully accomplished by a two-stage SSF process, which combines acid-pretreated bagasse, B. coagulans precultivated in the presence of furfural as microorganism, and GC220 as enzyme cocktail. The process may be further improved by enhancing enzyme hydrolysis activities at high lactic acid concentrations.

Isolation of a genetically accessible thermophilic xylan degrading bacterium from compost
Daas, Tijn ; Weijer, Tom van de; Vos, Willem M. de; Oost, John van der; Kranenburg, Richard van - \ 2016
Biotechnology for Biofuels 9 (2016). - ISSN 1754-6834
CMC - Compost - Electroporation - Fermentation - Geobacillus - Lactic acid - Thermophile - Xylan

Background: Due to the finite nature of global oil resources we are now faced with the challenge of finding renewable resources to produce fuels and chemicals in the future. Lactic acid has great potential as a precursor for the production of bioplastics alternatives to conventional plastics. Efficient lactic acid fermentation from non-food lignocellulosic substrates requires pretreatment and saccharification to generate fermentable sugars. A fermentation process that requires little to no enzyme additions, i.e. consolidated bioprocessing would be preferred and requires lactic acid-producing organisms that have cellulolytic and/or hemicellulolytic activity. Results: To obtain candidate production strains we have enriched and isolated facultative anaerobic (hemi) cellulolytic bacterial strains from compost samples. By selecting for growth on both cellulose and xylan, 94 Geobacillus strains were isolated. Subsequent screening for lactic acid production was carried out from C6 and C5 sugar fermentations and a selection of the best lactic acid producers was made. The denitrifying Geobacillus thermodenitrificans T12 was selected for further research and was rendered genetically accessible. In fermentations on a mixture of glucose and xylose, a total of 20.3 g of lactic acid was produced with a yield of 0.94 g product/g sugar consumed. In addition, strain T12 is capable of direct conversion of beech wood xylan to mainly lactic acid in minimal media. Conclusions: We have demonstrated that G. thermodenitrificans T12 is genetically accessible and produces lactic acid as its main fermentation product on glucose, xylose and a mixture thereof. Strain T12 was additionally used for the direct conversion of xylan to lactic acid. The genetic accessibility of the T12 strain provides a solid basis for the development of this strain into a host for consolidated bioprocessing of biomass to lactic acid.

Does canine inflammatory bowel disease influence gut microbial profile and host metabolism?
Xu, Jia ; Verbrugghe, Adronie ; Lourenço, Marta ; Janssens, Geert P.J. ; Liu, Daisy J.X. ; Wiele, Tom Van de; Eeckhaut, Venessa ; Immerseel, Filip Van; Maele, Isabel Van de; Niu, Yufeng ; Bosch, Guido ; Junius, Greet ; Wuyts, Brigitte ; Hesta, Myriam - \ 2016
BMC Veterinary Research 12 (2016)1. - ISSN 1746-6148
Acylcarnitine profile - Butyrate-producing bacteria - Citrulline - Dog - Fermentation - Inflammatory bowel disease - Lactobacillus - Microbiota - Short-chain fatty acid

Background: Inflammatory bowel disease (IBD) refers to a diverse group of chronic gastrointestinal diseases, and gut microbial dysbiosis has been proposed as a modulating factor in its pathogenesis. Several studies have investigated the gut microbial ecology of dogs with IBD but it is yet unclear if this microbial profile can alter the nutrient metabolism of the host. The aim of the present study was to characterize the faecal bacterial profile and functionality as well as to determine host metabolic changes in IBD dogs. Twenty-three dogs diagnosed with IBD and ten healthy control dogs were included. Dogs with IBD were given a clinical score using the canine chronic enteropathy clinical activity index (CCECAI). Faecal short-chain fatty acids (SCFA) and ammonia concentrations were measured and quantitative PCR was performed. The concentration of plasma amino acids, acylcarnitines, serum folate, cobalamin, and indoxyl sulfate was determined. Results: No significant differences in the abundance of a selection of bacterial groups and fermentation metabolites were observed between the IBD and control groups. However, significant negative correlations were found between CCECAI and the faecal proportion of Lactobacillus as well as between CCECAI and total SCFA concentration. Serum folate and plasma citrulline were decreased and plasma valine was increased in IBD compared to control dogs. Increased plasma free carnitine and total acylcarnitines were observed in IBD compared with control dogs, whereas short-chain acylcarnitines (butyrylcarnitine + isobutyrylcarnitine and, methylmalonylcarnitine) to free carnitine ratios decreased. Dogs with IBD had a higher 3-hydroxyisovalerylcarnitine + isovalerylcarnitine to leucine ratio compared to control dogs. Conclusions: Canine IBD induced a wide range of changes in metabolic profile, especially for the plasma concentrations of short-chain acylcarnitines and amino acids, which could have evolved from tissue damage and alteration in host metabolism. In addition, dogs with more severe IBD were characterised by a decrease in faecal proportion of Lactobacillus.

1H NMR-based metabolomics approach for understanding the fermentation behaviour of Bacillus licheniformis
Yan, Zheng ; Zheng, Xiaowei ; Han, Bei Zhong ; Yan, Yin Zhuo ; Zhang, Xin ; Chen, Jing Yu - \ 2015
Journal of the Institute of Brewing 121 (2015)3. - ISSN 0046-9750 - p. 425 - 431.
<sup>1</sup>H NMR - Bacillus licheniformis - Daqu - Fermentation - Metabolic profile

Bacillus licheniformis has been found to be one of the persistent dominant microorganisms in Daqu, which is a traditional fermentation starter, and it has been used to intensify certain strains. To understand the impact of B. licheniformis on Daqu, the fermentation behaviour of B. licheniformis was studied using 1H NMR-based non-targeted analysis and principal component analysis. During the fermentation, 53 compounds were identified. Among them, seven compounds were largely consumed and 17 metabolites were largely accumulated. The macromolecular starch and cellulose were degraded by B. licheniformis, and then utilized to produce acetic acid, lactic acid, propionic acid, succinate acid, etc. Principal component analysis was carried out to study the variations of analytes during the fermentation. Samples collected at each time point could be clearly discriminated and the biomarkers of each time point were defined. A variety of biochemical compounds (such as acetate, ethanol, lactate, pyruvate, malate, maltose and sucrose) were changed during the fermentation of B. licheniformis. The results are useful to reveal how and why B. licheniformis becomes dominant in Daqu, and to reveal its impact on the aroma formation of Daqu and its derived products.

Recombinant gelatin and collagen from methylotrophic yeasts
Bruin, E.C. de - \ 2002
University. Promotor(en): N.C.M. Laane; Frits de Wolf. - S.l. : S.n. - ISBN 9789058085832 - 110
collageen - gelatine - recombinant dna - hansenula - Hansenula polymorpha - Pichia pastoris - collagen - gelatin - Methylotrophic yeast - Fermentation - Secretion - Recombinant expression
<font size="3"><p>Based on its structural role and compatibility within the human body, collagen is a commonly used biomaterial in medical applications, such as cosmetic surgery, wound treatment and tissue engineering. Gelatin is in essence denatured and partly degraded collagen and is, as a result of its unique functional and chemical properties, also used in many medical and pharmaceutical products. Collagen and gelatin are traditionally extracted from animal tissues. The quality and the characteristics of the proteins are not very reproducible in today's batch-to-batch production processes and recently, potential contamination of collagen and gelatin with viruses and prions (causing BSE) became a matter of concern. BSE is thought to cause a new variety of the brain- wasting Creutzfeldt-Jacob disease in humans.</p><p>Recombinant DNA technology may provide safe collagen and gelatins from which the quality and characteristics can precisely be controlled and reproduced and, in addition, opens up possibilities for novel functional "tailor-made" proteins.For the heterologous production of animal proteins yeasts are frequently used. Since yeasts are eukaryotes, most translational modification, needed for functionality and stability of recombinant animal proteins, normally occur. However prolyl 4-hydroxylation, essential for gelling properties of recombinant gelatin and thermal stability of recombinant collagen, is generally considered to be absent in yeast systems.</p><p>In this study we explored the methylotrophic yeasts <em>Hansenula polymorpha</em> and <em>Pichia pastoris</em> for their use as recombinant production systems of natural and "tailor-made" gelatins and human collagen.We found that both yeasts are well able to cope with the repetitive gene sequences encoding animal gelatin and human collagen and showed that <em>P. pastoris</em> can produce synthetic gelatins with highly hydrophilic properties at high levels. Furthermore, it was discovered that <em>H. polymorpha</em> unexpectedly produced endogenous collagen-like proteins with 4-hydroxyproline amino acid residues. This finding indicated that the yeast <em>H. polymorpha</em> , in contract to what was generally believed, must contain intrinsic proly 4-hydroxyalse activity. Indeed, expression of murine gelatin in <em>H. polymorpha</em> yielded a secreted and hydroxylated product. We also investigated if <em>H. polymorpha</em> could be used for the production of recombinant human collagen. Intract human collagen trimers were obtained but they were not stable at temperatures higher than 15 °C, indicating that hydroxylation in the product was poor.</p><p>In the course of this study we found putative prolyl 4-hydroxylase genes in different eukaryotic microbial systems. In the future these genes may be used to further develop yeasts into cell factories for the production of animal gelatins and thermally stable human collagen.
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