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1.
Celiac disease (CD) is an immune-mediated disease, triggered in genetically susceptible individuals by ingesting gluten from wheat, rye, barley, and other closely related cereal grains. Currently, the estimated prevalence of CD is around 1 % of the population in the western world and medical nutritional therapy (MNT) is the only accepted treatment for celiac disease. To date, the replacement of gluten in bread presents a significant technological challenge for the cereal scientist due to the low baking performance of gluten free products (GF). The increasing demand by the consumer for high quality gluten-free (GF) bread, clean labels and natural products is rising. Sourdough has been used since ancient times for the production of rye and wheat bread, its universal usage can be attributed to the improved quality, nutritional properties and shelf life of sourdough based breads. Consequently, the exploitation of sourdough for the production of GF breads appears tempting. This review will highlight how sourdough LAB can be an efficient cell factory for delivering functional biomolecules and food ingredients to enhance the quality of gluten free bread. 相似文献
2.
3.
Thomsen MH 《Applied microbiology and biotechnology》2005,68(5):598-606
This mini-review describes the concept of the green biorefinery and lists a number of suitable agricultural by-products, which
can be used for production of bioenergy and/or biochemicals. A process, in which one possible agricultural by-product from
the green crop drying industry, brown juice, 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 ≈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. 相似文献
4.
Pieter De Frenne An De Schrijver Bente J. Graae Robert Gruwez Wesley Tack Filip Vandelook Martin Hermy Kris Verheyen 《Ecological Research》2010,25(1):163-171
Open-top chambers (OTCs) are widely used experimental warming devices in open-field ecosystems such as tundra and alpine heath.
However, knowledge of their performance in temperate deciduous forest ecosystems is largely lacking. The application of OTCs
in forests might become important in the future since the effects of climate warming on growth, reproduction, and future distribution
of understorey forest herbs have rarely been investigated. Therefore, polycarbonate OTCs covered with (OTCs+GF) and without
permeable polypropylene GardenFleece (OTCs−GF) were installed in a temperate deciduous forest to create an experimental warming
gradient. Short-term responses in phenology, growth, and reproduction of a model understorey forest herb (Anemone nemorosa L.) to OTC installation were determined. In a second growing season, an in-depth study of multiple abiotic conditions inside
OTCs−GF was performed. Both OTCs+GF and OTCs−GF raised air and soil temperature in a realistic manner (ca. +0.4°C to +1.15°C),
but OTCs−GF only in the leafless period (up to +1.5°C monthly average soil temperature). The early flowering forest herb A. nemorosa also showed a clear phenotypic response to OTC installation. Based on these facts and the large ecological drawbacks associated
with OTCs+GF (mostly in connection with a higher relative air humidity and a lower light quantity) and very modest abiotic
changes in OTCs−GF, we encourage the use of OTCs−GF in deciduous forest ecosystems for evaluating climate-warming effects
on early flowering understorey forest herbs. There is also a potential to use this warming method on later flowering species,
but this needs further research. 相似文献
5.
Biotechnology of succinic acid production and markets for derived industrial products 总被引:29,自引:4,他引:25
Succinic acid, derived from fermentation of agricultural carbohydrates, has a specialty chemical market in industries producing
food and pharmaceutical products, surfactants and detergents, green solvents and biodegradable plastics, and ingredients to
stimulate animal and plant growth. As a carbon-intermediate chemical, fermentation-derived succinate has the potential to
supply over 2.7 × 108 kg industrial products/year including: 1,4-butanediol, tetrahydrofuran, γ-butyrolactone, adipic acid, n-methylpyrrolidone and linear aliphatic esters. Succinate yields as high as 110 g/l have been achieved from glucose by the
newly discovered rumen organism Actinobacillus succinogenes. Succinate fermentation is a novel process because the greenhouse gas CO2 is fixed into succinate during glucose fermentation. New developments in end-product recovery technology, including water-splitting
electrodialysis and liquid/liquid extraction have lowered the cost of succinic acid production to U.S. $ 0.55/kg at the 75 000
tonne/year level and to $ 2.20/kg at the 5000 tonne/year level. Research directions aimed at further improving the succinate
fermentation economics are discussed.
Received: 27 October 1998 / Received revision: 22 January 1999 / Accepted: 22 January 1999 相似文献
6.
Sarah Hammond Michael O’Shea 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2007,193(11):1125-1137
There are two modes of flight initiation in Drosophila melanogaster—escape and voluntary. Although the circuitry underlying escape is accounted for by the Giant fibre (GF) system, the system
underlying voluntary flight initiation is unknown. The GF system is functionally complete before the adult fly ecloses, but
immature adults initially fail to react to a stimulus known to reliably evoke escape in mature adults. This suggests that
escape in early adulthood, ∼2-h post-eclosion, is not automatically triggered by the hard-wired GF system. Indeed, we reveal
that escape behaviour displays a staged emergence during the first hour post-eclosion, suggesting that the GF system is subject
to declining levels of suppression. Voluntary flight initiations are not observed at all during the period when the GF system
is released from its suppression, nor indeed for some time after. We addressed the question whether voluntary flight initiation
requires the GF system by observing take-off in Shak-B
2
mutant flies, in which the GF system is defunct. While the escape response is severely impaired in these mutants, they displayed
normal voluntary flight initiation. Thus, the escape mechanism is subject to developmental modulation following eclosion and
the GF system does not underlie voluntary flight.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
7.
Ni-Ni Guo Zong-Ming Zheng Yu-Lin Mai Hong-Juan Liu De-Hua Liu 《Applied microbiology and biotechnology》2010,86(2):701-707
The filtration in 1,3-propanediol (1,3-PD) downstream process is influenced by the large amounts of capsular polysaccharides
(CPS) produced by Klebsiella pneumoniae CGMCC 1.6366. The morphological and fermentation properties were investigated with the CPS-deficient mutant K. pneumoniae CGMCC 1.6366 CPS. Similar biomass was obtained with CGMCC 1.6366, and the mutant strain in batch cultures indicating the
cell growth was slightly inhibited by CPS defection. The viscosity of fermentation broth by mutant strain decreased by 27.45%.
The flux with ceramic membrane filter was enhanced from 168.12 to 303.6 l h−1 m−2, exhibiting the great importance for downstream processing of 1,3-PD fermentation. The products spectrum of mutant isolate
changed remarkably regarding to the concentration of fermentation products. The synthesis of important 1,3-PD and 2,3-butanediol
was enhanced from 9.73 and 4.06 g l−1 to 10.37 and 4.77 g l−1 in batch cultures. The noncapsuled K. pneumoniae provided higher 1,3-PD yield of 0.54 mol mol−1 than that of encapsuled wild parent in batch cultures. The fed-batch fermentation of mutant strain resulted in 1,3-PD concentration,
yield, and productivity of 78.13 g l−1, 0.53 mol mol−1, and 1.95 g l−1 h−1, respectively. 相似文献
8.
Selective expression of detoxifying glutathione transferases in mouse colon: effect of experimental colitis and the presence of bacteria 总被引:1,自引:1,他引:0
Glutathione transferases (GSTs) play a central role in the cellular defense against harmful endogenous compounds and xenobiotics in mouse and man. The gastrointestinal channel is constantly exposed to bacteria, bacterial products, and xenobiotics. In the present study the distribution of alpha, mu, and pi class GSTs was examined immunohistologically in the colon of conventional and germ-free (GF) mice subjected to experimental colitis. The tissues samples were from conventional mice with and without colitis induced by dextran sulfate sodium (DSS); GF mice treated with DSS or carrageenan; and GF mice inoculated with normal mouse bacterial flora as well as with Lactobacillus GG. In conventional as well as in GF mice the mu and pi class GSTs showed reduced intestinal expression when colitis was induced. In contrast, the level of GSTs reacting with antibodies directed against the alpha class, in particular mGST A4-4, was elevated after induction of inflammation. Of special interest is mGST A4-4 because of its high catalytic activity with toxic products of lipid peroxidation. In the colon of conventionalized GF mice that were given mouse intestinal flora, the mGST A4-4 expression was increased with time for several weeks, but then showed a decrease to a normal level. Additionally, the inoculation of GF mice with Lactobacillus GG induced all the intestinal GSTs studied. 相似文献
9.
R. Štěpánková J. Šinkora T. Hudcovic H. Kozáková H. Tlaskalová-Hogenová 《Folia microbiologica》1998,43(5):531-534
The aim of the study was to compare the phenotype of lymphocyte subpopulations of the GALT (gut-associated lymphatic tissue)
in germfree (GF) and conventionally (CV) reared rats,i.e. to analyze the effect of microbial colonization on the development of intestinal lymphocyte subsets. Surface marker characteristics
were studied in cell suspensions isolated from Peyer’s patches, mesenteric lymph nodes, spleen and the intraepithelial lymphocyte
compartment of 2- and 12-month old inbred AVN rats. The pattern of T lymphocyte phenotypes in Peyer’s patches, mesenteric
lymph nodes and spleen determined by FACS analysis did not reveal differences between GF and CV rats. In contrast, a 2-month
conventionalization of GF rats led to substantial changes in the composition of intestinal intraepithelial lymphocyte subsets
(IELs): increase of CD4+, CD8α+, CD8β+, TcR α/β+ bearing lymphocytes was observed after colonization of rats with normal microflora. Surprisingly, the relative numbers of
lymphocytes bearing TcR γ/δ+ did not change during conventionalization. The effect of aging was also studied and differences in IELs composition of aged
(GF) and (CV) rats were found to be more pronounced: 6,6% and 30% of lymphocytes bearing TcR α/β were present among IELs in
two-month old GF and CV rats, respectively. 30% of IELs in 2-month old GF rats, 80% of IEL from 12-month old CV rats were
found to bear TcR α/β. This finding demonstrates that during conventionalization and aging the TcR α/β bearing population
of IELs substantially expands. It suggests that mainly this lymphocyte subset responds to microflora stimuli and is probably
involved in the protection of the epithelial cell layer of intestinal mucosa. 相似文献
10.
Jean-Luc Tholozan Jean-Philippe Grivet Christelle Vallet 《Archives of microbiology》1994,162(6):401-408
Pectinatus frisingensis, a recently described species of anaerobic mesophilic beer-spoilage bacteria, grows by fermenting various organic compounds,
and produces mainly propionate, acetate, and succinate. Although acrylate and succinate were both dismutated by dense resting-cell
suspensions, propionate production proceeded through the succinate pathway: [3-13C]pyruvate consumption led to equal 13C-labeling of propionate on methyl and methylene groups. Growth on glucose or glycerol led to a similar propionate to acetate
ratio, suggesting dihydroxyacetone phosphate as being a common metabolic intermediate. Diacetyl, 1,3-propanediol, and 2,3-butanediol
were not growth substrates or fermentation products, but they were all dismutated by dense resting-cell suspensions to acetate
and propionate. Acetoin was a minor fermentation product. The consumption of [2-13C] or [3-13C]pyruvate by dense resting-cell suspensions demonstrated the involvement of two equivalent pyruvate molecules during acetoin
production. Key enzymes involved in this metabolism were measured in anoxic cell-free extracts. A tentative metabolic pathway
to the main fermentation products was proposed from the above results.
Received: 17 February 1994 / Accepted: 30 August 1994 相似文献
11.
pH affected significantly the growth and the glucose fermentation pattern of Propionibacterium microaerophilum. In neutral conditions (pH 6.5–7.5), growth and glucose fermentation rate (qs) were optimum producing propionate, acetate,
CO2, and formate [which together represented 90% (wt/wt) of the end products], and lactate representing only 10% (wt/wt) of the
end products. In acidic conditions, propionate, acetate, and CO2 represented nearly 100% (wt/wt) of the fermentation end products, whereas in alkaline conditions, a shift of glucose catabolism
toward formate and lactate was observed, lactate representing 50% (wt/wt) of the fermentation end products. The energy cellular
yields (Y
X/ATP), calculated (i) by taking into account extra ATP synthesized through the reduction of fumarate into succinate, was 6.1–7.2
g mol−1. When this extra ATP was omitted, it was 11.9–13.1 g mol−1. The comparison of these values with those of Y
X/ATP in P. acidipropionici and other anaerobic bacteria suggested that P. microaerophilum could not synthesize ATP through the reduction of fumarate into succinate and therefore differed metabolically from P. acidipropionici.
Received: 8 April 2002 / Accepted: 8 May 2002 相似文献
12.
Tianli Tian Qiling Sun Jing Shen Tao Zhang Pei Gao Qun Sun 《World journal of microbiology & biotechnology》2008,24(6):861-866
Rhizopus microsporus isolated by our laboratory was able to transform polydatin into resveratrol and emodin-8-β-d-glucoside into emodin, respectively, through the fermentation of Polygonum cuspidatum Sieb. et Zucc. The fermentation products were separated and purified by H1020 resin and silica gel column chromatography.
Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) were used to identify the products and evaluate
the transformation efficiency. A variety of parameters of submerged state fermentation, including the growth characteristics,
the change of β-glucosidase activity and the amount of polydatin, resveratrol, emodin-8-β-d-glucoside, emodin, and the dissolved oxygen, were monitored simultaneously. The amount of resveratrol yielded increased dramatically
from 0.04 g/l at the beginning to the maximum value of 0.34 g/l at 36 h of fermentation, and emodin was from 0.4 g/l to 0.65 g/l
at 80 h. The transformation rate of glycosides reached 98% and the purity of both resveratrol and emodin was 95%. 相似文献
13.
Thiosulfate (S2O3
2–) is a natural product that is widely utilized in natural ecosystems as an electron sink or as an electron donor. However,
the major biological source(s) of this thiosulfate is unknown. We present the first report that taurine (2-aminoethanesulfonate),
the major mammalian solute, is subject to fermentation. This bacterial fermentation was found to be catalyzed by a new isolate,
strain GKNTAU, a strictly anaerobic, gram-positive, motile rod that formed subterminal spores. Thiosulfate was a quantitative
fermentation product. The other fermentation products were ammonia and acetate, and all could be formed by cell-free extracts.
Received: 19 February 1997 / Accepted: 12 May 1997 相似文献
14.
In this study, a novel generic feedstock production strategy based on solid-state fermentation (SSF) has been developed and applied to the fermentative production of succinic acid. Wheat was fractionated into bran, gluten and gluten-free flour by milling and gluten extraction processes. The bran, which would normally be a waste product of the wheat milling industry, was used to produce glucoamylase and protease enzymes via SSF using Aspergillus awamori and Aspergillus oryzae, respectively. The resulting solutions were separately utilised for the hydrolysis of gluten-free flour and gluten to generate a glucose-rich stream of over 140gl(-1) glucose and a nitrogen-rich stream of more than 3.5gl(-1) free amino nitrogen. A microbial feedstock consisting of these two streams contained all the essential nutrients required for succinic acid fermentations using Actinobacillus succinogenes. In a fermentation using only the combined hydrolysate streams, around 22gl(-1) succinic acid was produced. The addition of MgCO(3) into the wheat-derived medium improved the succinic acid production further to more than 64gl(-1). These results demonstrate the SSF-based strategy is a successful approach for the production of a generic feedstock from wheat, and that this feedstock can be efficiently utilised for succinic acid production. 相似文献
15.
Energy-efficient recovery of butanol from model solutions and fermentation broth by adsorption 总被引:4,自引:0,他引:4
This article discusses the separation of butanol from aqueous solutions and/or fermentation broth by adsorption. Butanol fermentation
is also known as acetone butanol ethanol (ABE) or solvent fermentation. Adsorbents such as silicalite, resins (XAD-2, XAD-4,
XAD-7, XAD-8, XAD-16), bone charcoal, activated charcoal, bonopore, and polyvinylpyridine have been studied. Use of silicalite
appears to be the more attractive as it can be used to concentrate butanol from dilute solutions (5 to 790–810 g L−1) and results in complete desorption of butanol (or ABE). In addition, silicalite can be regenerated by heat treatment. The
energy requirement for butanol recovery by adsorption–desorption processes has been calculated to be 1,948 kcal kg−1 butanol as compared to 5,789 kcal kg−1 butanol by steam stripping distillation. Other techniques such as gas stripping and pervaporation require 5,220 and 3,295 kcal kg−1 butanol, respectively.
Mention of trade names of commercial products in this article/publication is solely for the purpose of providing scientific
information and does not imply recommendation or endorsement by the United States Department of Agriculture. 相似文献
16.
M. G. Bezhuashvili R. K. Nutsubidze M. S. Pataraya 《Applied Biochemistry and Microbiology》2000,36(2):142-145
Conversion of lignins contained in solid parts of Rkatsiteli grapes (crests, seeds, and skin) during alcoholic fermentation
by wine yeast in Reader’s medium was studied. Various species of wine yeast were used:Saccharomyces oviformis, S. vini Kakhuri 42,S. chodati Teliani 79, andS. uvarum Tsinandali 77. We found that lignins from solid parts of grapes are partially decomposed during alcoholic fermentation, which
releases low-molecular-weight aromatic compounds into the medium. A peculiar feature of lignin decomposition during alcoholic
fermentation is the formation of reduction products. 相似文献
17.
Hydrolysis of isoflavone glycosides by Bacillus subtilis natto NTU-18 in black soymilk is reported. At the concentration of 3–5% (w/v), black soymilk in flask cultures, the isoflavones, daidzin, and genistin were highly deglycosylated within 24 h. Deglycosylation of isoflavones was further carried out in a 7-l fermenter with 5% black soymilk. During the fermentation, viable cells increased from 103 to 109 CFU ml−1 in 15 h, and the activity of β-glucosidase appeared at 8 h after inoculation and reached a maximum (3.3 U/ml) at 12 h, then decreased rapidly. Deglycosylation of isoflavone glycosides was observed at the same period, the deglycosylation rate of daidzin and genistin at 24 h was 100 and 75%, respectively. It is significantly higher than the previous reports of fermentation with lactic acid bacteria. In accordance with the deglycosylation of isoflavone glycosides, the estrogenic activity of the 24 h fermented black soymilk for ERβ estrogen receptor increased to threefold; meanwhile, the fermented broth activated ERα estrogen receptor to a less extent than ERβ. These results suggest that this fermentation effectively hydrolyzed the glycosides from isoflavone in black soymilk and the fermented black soymilk has the potential to be applied to selective estrogen receptor modulator products. 相似文献
18.
Biotechnological production of mannitol and its applications 总被引:1,自引:0,他引:1
Mannitol, a naturally occurring polyol (sugar alcohol), is widely used in the food, pharmaceutical, medical, and chemical
industries. The production of mannitol by fermentation has become attractive because of the problems associated with its production
chemically. A number of homo- and heterofermentative lactic acid bacteria (LAB), yeasts, and filamentous fungi are known to
produce mannitol. In particular, several heterofermentative LAB are excellent producers of mannitol from fructose. These bacteria
convert fructose to mannitol with 100% yields from a mixture of glucose and fructose (1:2). Glucose is converted to lactic
acid and acetic acid, and fructose is converted to mannitol. The enzyme responsible for conversion of fructose to mannitol
is NADPH- or NADH-dependent mannitol dehydrogenase (MDH). Fructose can also be converted to mannitol by using MDH in the presence
of the cofactor NADPH or NADH. A two enzyme system can be used for cofactor regeneration with simultaneous conversion of two
substrates into two products. Mannitol at 180 g l−1 can be crystallized out from the fermentation broth by cooling crystallization. This paper reviews progress to date in the
production of mannitol by fermentation and using enzyme technology, downstream processing, and applications of mannitol. 相似文献
19.
20.
The effect of intestinal colonization withBifidobacterium bifidum (Gram-positive anaerobic bacterium colonizing the intestine of healthy new-born mammals, exhibiting a probiotic effect, protecting
the intestinal mucosa against colonization by pathogenic microflora) on enterocyte brush-border enzymes was examined in weaned
23-d- and in 2-month-old gnotobiotic inbred mice and compared with that in corresponding germ-free (GF) and conventional (CV)
controls. The two groups of GF mice were associated with humanB. bifidum 11 d before the end of the experiment. Specific activity of enterocyte brush-border enzymes—lactase, alkaline phosphatase
and γ-glutamyltranspeptidase was significantly higher in both age groups of GF mice in comparison with CV ones; on the other
hand, sucrase and glucoamylase activities were higher in CV mice. Monoassociation withB. bifidum accelerates biochemical maturation of enterocytes resulting in a shift of specific activities of brush-border enzymes between
the values found for GF and CV mice. This effect ofB. bifidum supplementation was less pronounced for alkaline phosphatase, sucrase, glucoamylase and dipeptidyl peptidase IV in immature
gut of weaned mice than of 2-month-old ones. 相似文献