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At least 955 records · Page 53Linked to original sources
PubMed1994

Antioxidative effects of a processed grain food.

Antioxidant biofactor: AOB is a unique processed grain food. It is a yellow-green powder. It contains the following extracts: germ extracts, soybean, rice bran, tear grass, sesame, wheat, citron, green tea, green leaf extract, and malted rice. These materials were slowly roasted under a powdered oure at less than 60 degrees C and fermented with Aspergillus oryzae over 3 days to transform each ingredient into low molecular weight substances. These conditions were different by each material, environmental humidity and temperature. It probably contains a variety of substances having antioxidant activity including flavonoids, alpha-tocopherol, vitamin C, and tannins. We investigated its antioxidative properties using electron spin resonance (ESR) and autoxidation of rat brain homogenates. The superoxide, hydroxyl radical, and the stable free radical, diphenyl-p-picrylhydrazyl (DPPH) radical scavenging activity of AOB was investigated using ESR spectrometry. In an in vitro study, a suspension of AOB was added directly to a superoxide generating system (hypoxanthine-xanthine oxidase; HX/XO) and investigated using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trapping agent. At final concentrations of 0.01, 0.05, and 0.1 mg/ml, AOB dose-dependent scavenging activity was observed as 0.103, 0.619, and 1.369 U/ml, respectively. A concentration of 1.0 mg/ml completely scavenged DMPO-OOH signals; 1.0 mg/ml of AOB inhibited the DMPO-OH signal generated by Fenton's reaction, but its inhibitory effect was not competitive, and was inhibition of the Fenton's reaction. 1.0, 3.0, and 5.0 mg/ml of AOB were significantly inhibited the DPPH radical. In an in vivo study, rats were fed AOB orally at doses of 1 or 5 g/day for 24 h or for 3 days and the superoxide scavenging activity was measured in plasma. With the administration of 1 g/day for 3 days, the superoxide scavenging activity was about 1.8 times that of the control group fed a basal diet; 1.5 times the control with 5 g/day for 1 day, and 2.6 times the control with 5 g/day for 3 days, all of which represented significant increases in superoxide scavenging activity. AOB strongly inhibited the autoxidation of rat brain homogenates in vitro in a dose-dependent manner. However, each ingredient before roast and fermentation little inhibited lipid peroxidation. Roasting and fermentation with A. oryzae way be important to transform each ingredient into low molecular weight substances. Therefore, it was suggested that AOB possesses strong antioxidant and free radical scavenging activities.

Animals↗
PubMed2002

The bacteriocins of ruminal bacteria and their potential as an alternative to antibiotics.

Beef cattle have been fed ionophores and other antibiotics for more than 20 years to decrease ruminal fermentation losses (e.g methane and ammonia) and increase feed efficiency, and these improvements have been explained by an inhibition of gram-positive ruminal bacteria. Ionophores are not used to treat human disease, but there has been an increased perception that antibiotics should not be used as feed additives. Some bacteria produce small peptides (bacteriocins) that inhibit gram-positive bacteria. In vitro experiments indicated that the bacteriocin, nisin, and the ionophore, monensin, had similar effects on ruminal fermentation. However, preliminary results indicated that mixed ruminal bacteria degraded nisin, and the ruminal bacterium, Streptococcus bovis, became highly nisin-resistant. A variety of ruminal bacteria produce bacteriocins, and bacteriocin production has, in some cases, been correlated with changes in ruminal ecology. Some ruminal bacteriocins are as potent as nisin in vitro, and resistance can be circumvented. Based on these results, ruminal bacteriocins may provide an alternative to antibiotics in cattle rations.

Animals↗
PubMed1993

Aerobic stability and in vitro fiber digestibility of microbially inoculated corn and sorghum silages.

Silage deteriorates readily when exposed to air, resulting in DM losses. Inoculation of silage with lactic acid bacteria may aid fermentation, but effects on aerobic stability are unclear. Two experiments were conducted to determine the effect of commercial bacterial inoculants on aerobic stability and in vitro fiber digestibility of silage. Corn (Zea mays L.; Exp. 1) or sorghum (Sorghum bicolor [L.] Moench; Exp. 2) forage (30% DM) was inoculated (1.1 x 10(5) colony forming units/g of fresh forage) with lactic acid bacteria (Pioneer brand 1174 on corn, Pioneer brand 1129 on sorghum) or bacterial inoculant plus an antifungal agent (potassium sorbate at .5 mg/g of fresh forage) and ensiled in 19-L microsilos. Corn was ensiled for 40 or 186 d and sorghum was ensiled for 30 or 160 d (five microsilos per treatment per ensiling time combination). Silages were exposed to air for 7 to 9 d after opening, and temperature was monitored daily. Water-soluble carbohydrates, pH, NDF, ADF, and in vitro digestibility of NDF and ADF were determined before and after ensiling and on exposed silages. Inoculation reduced (P < .05) silage pH in both corn and sorghum but did not prevent aerobic deterioration of the silages. Temperatures during aerobic exposure of silages did not differ (P > .05) between uninoculated and inoculated silages. Inoculant treatment did not affect (P > .05) concentrations or digestibility of NDF in corn; however, NDF and ADF concentration and in vitro digestibility of NDF increased (P < .05) with time of ensiling in sorghum silage, and in vitro ADF digestibility increased (P < .05) with time of ensiling in corn silage.

Aerobiosis↗
PubMed1980

[Possible therapy with and limits of gene technology (author's transl)].

This paper is an attempt to discuss hopes and limits of recent advances in genetechnology especially in respect of their medical applications. Although advances in modern biology are enormous no realistic prognoses can be given at the moment to their medical application in correcting inborn errors of metabolism at the level of the gene. However the production by fermentation of biosubstances like insulin, interferon and hormones, just to name a few, is not only possible but already carried out in many laboratories in USA. Therefore therapy of clinical manifestations like metabolic disorders, viral infections and hormone insufficiencies should become feasible based on the nearly unlimited in vitro production of the necessary compounds.

Animals↗
PubMed2000

Comparative effects of three resistant starch preparations on transit time and short-chain fatty acid production in rats.

A high-fiber diet may protect against colon cancer because of the butyrate generated in the colon by bacterial fermentation of nonstarch polysaccharides. Butryrate can reverse neoplastic changes, at least in vitro, and resistant starch (RS) represents a source of butyrate in vivo. We examined the effects of replacing normal maize starch in the diet of rats with three preparations of RS on the amounts of starch, butyrate, and other short-chain fatty acids in the cecum. We examined the effects on fecal bulking and transit time, which have been suggested to protect against colon cancer. The RS preparations that we tested were potato starch, high-amylose maize starch, and an alpha-amylase-treated high-amylose maize starch. All had major effects on fecal weight and on the weight of the cecum but only slightly shortened transit times. All increased the amount of starch reaching the cecum and increased short-chain fatty acid production in the cecum; potato starch had the greatest effect and high-amylose maize starch the least. Potato starch, unlike high-amylose maize starch, enhanced the proportion of butyrate. Thus there were marked differences among sources of RS, even though these were all classified as RS2. The significance for colon cancer is discussed.

Animals↗
PubMed1998

Prevention of peroxidative stress in rats fed on a low vitamin E-containing diet by supplementing with a fermented bovine milk whey preparation: effect of lactic acid and beta-lactoglobulin on the antiperoxidative action.

We examined the antiperoxidative properties of a fermented bovine milk whey preparation in rats fed on a low vitamin E-containing diet and identified the active principle in the preparation. An exogenous supply of either lactic acid or an amino acid mixture simulated the unfermented whey proteins to prevent red blood cell (RBC) hemolysis and to lower liver thiobarbituric acid reactive substances (TBARS). The supply of either whey proteins or beta-lactoglobulin resulted in an increase in liver GSH and prevented iron-mediated lipoprotein peroxidation. These protein effects were reproduced in rats orally administered with either GSH or its precursor, gamma-glutamylcysteine. The amount of TBARS formed during in vitro lipoprotein peroxidation were positively correlated with liver TBARS. These results suggest that fermented milk products containing lactic acid and bovine milk whey proteins can ameliorate peroxidative stress in tissues subjected to vitamin E deficiency.

Animals↗
PubMed2000

Regulation of fermentative capacity and levels of glycolytic enzymes in chemostat cultures of Saccharomyces cerevisiae.

Regulation of fermentative capacity was studied in chemostat cultures of two Saccharomyces cerevisiae strains: the laboratory strain CEN.PK113-7D and the industrial bakers' yeast strain DS28911. The two strains were cultivated at a fixed dilution rate of 0.10 h(-1) under various nutrient limitation regimes: aerobic and anaerobic glucose limitation, aerobic and anaerobic nitrogen limitation on glucose, and aerobic ethanol limitation. Also the effect of specific growth rate on fermentative capacity was compared in glucose-limited, aerobic cultures grown at dilution rates between 0.05 h(-1) and 0.40 h(-1). Biomass yields and metabolite formation patterns were identical for the two strains under all cultivation conditions tested. However, the way in which environmental conditions affected fermentative capacity (assayed off-line as ethanol production rate under anaerobic conditions) differed for the two strains. A different regulation of fermentative capacity in the two strains was also evident from the levels of the glycolytic enzymes, as determined by in vitro enzyme assays. With the exception of phosphofructokinase and pyruvate decarboxylase in the industrial strain, no clear-cut correlation between the activities of glycolytic enzymes and the fermentative capacity was found. These results emphasise the need for controlled cultivation conditions in studies on metabolic regulation in S. cerevisiae and demonstrate that conclusions from physiological studies cannot necessarily be extrapolated from one S. cerevisiae strain to the other.

Journal Article↗
PubMedDate not supplied

In vitro testing of xylitol as an anticariogenic agent.

A number of studies involving xylitol chewing gum have demonstrated that xylitol is both noncariogenic and anticariogenic. The ability of xylitol to act as an anticariogenic agent most likely is due to its ability to be transported into caries-causing oral bacteria and inhibiting fermentation either by depleting the cell of high-energy phosphate or by poisoning the glycolytic system. In vitro tests were conducted to determine the concentration of xylitol required to inhibit the growth of three strains of oral streptococcus (S. mutans, S. salivarius, and S. sanguis). All three strains were inhibited significantly at xylitol concentrations of 12.5% and higher; however, only S. mutans was inhibited significantly at a xylitol concentration of 1.56%.

Analysis of Variance↗
PubMed1999

Disk diffusion susceptibility test development for the new glycylcycline, GAR-936.

The in vitro activity of GAR-936, a new semisynthetic glycylcycline, was evaluated in comparison with two tetracyclines and the disk diffusion susceptibility test was assessed. Nearly 700 recent clinical isolates were tested by reference broth microdilution and disk diffusion (two disk contents) methods. Among the Enterobacteriaceae, GAR-936 was generally two- to 16-fold more active than other tetracyclines. All enteric bacilli MIC90 results were < or = 4 micrograms/mL; the exception being Proteus mirabilis and indole-positive Proteae (> or = 8 micrograms/mL). GAR-936 demonstrated excellent activity against all Gram-positive cocci with Enterococcus spp. (including vancomycin-resistant isolates) inhibited at 0.25 microgram/mL (GAR-936 MIC90, 0.12 or 0.25 microgram/mL) and the oxacillin-resistant Staphylococcus aureus strains were inhibited at < or = 0.25 microgram/mL. GAR-936 demonstrated good potency against several non-fermentative bacteria, but possessed limited activity against Pseudomonas aeruginosa (MIC50, 8 micrograms/mL). In vitro susceptibility test methods were developed (disk diffusion versus reference MIC results) and tentative breakpoints were proposed. Using susceptibility criteria of either < or = 2 or < or = 4 micrograms/mL, GAR-936 in vitro susceptibility tests demonstrated rare significant serious inter-method discords (< or = 1.2%) and an absolute agreement between test results of 92.3 to 96.2%. These results indicate that GAR-936 has potent in vitro activity against a wide range of clinically important rapidly growing pathogenic bacteria, and that this novel glycylcycline candidate for clinical use should be further developed.

Anti-Bacterial Agents↗
PubMed1995

Sourdough fermentation or addition of organic acids or corresponding salts to bread improves nutritional properties of starch in healthy humans.

Postprandial blood glucose and insulin responses to barley bread containing organic acids or corresponding salts were evaluated in healthy human subjects. The satiety score and the rate and extent of in vitro starch digestion were also studied. Lactic acid was generated by use of a homofermentative starter culture or added to the dough. In addition, products were baked with Ca-lactate, or with Na-propionate at two different concentrations. Consumption of the product baked with a high concentration of Na-propionate significantly lowered the postprandial blood glucose and insulin responses, and significantly prolonged the duration of satiety compared with all other breads. When subjects consumed the breads baked with sourdough, lactic acid and Na-propionate, their glucose and insulin responses were reduced compared with the wholemeal bread alone. The rate of in vitro amylolysis was reduced only by ingestion of the breads containing lactic acid, suggesting that the beneficial impact of Na-propionate on metabolic responses and satiety was related to effects other than a reduced rate of starch hydrolysis. All bread products had a similar concentration of in vitro resistant starch of 1.3-2.1 g/100 g (starch basis). It is concluded that sourdough baking and other fermentation processes may improve the nutritional features of starch. The results also demonstrate that certain salts of organic acids may have metabolic effects.

Adult↗
PubMed2005

In vitro determination of prebiotic properties of oligosaccharides derived from an orange juice manufacturing by-product stream.

Fermentation properties of oligosaccharides derived from orange peel pectin were assessed in mixed fecal bacterial culture. The orange peel oligosaccharide fraction contained glucose in addition to rhamnogalacturonan and xylogalacturonan pectic oligosaccharides. Twenty-four-hour, temperature- and pH-controlled, stirred anaerobic fecal batch cultures were used to determine the effects that oligosaccharides derived from orange products had on the composition of the fecal microbiota. The effects were measured through fluorescent in situ hybridization to determine changes in bacterial populations, fermentation end products were analyzed by high-performance liquid chromatography to assess short-chain fatty acid concentrations, and subsequently, a prebiotic index (PI) was determined. Pectic oligosaccharides (POS) were able to increase the bifidobacterial and Eubacterium rectale numbers, albeit resulting in a lower prebiotic index than that from fructo-oligosaccharide metabolism. Orange albedo maintained the growth of most bacterial populations and gave a PI similar to that of soluble starch. Fermentation of POS resulted in an increase in the Eubacterium rectale numbers and concomitantly increased butyrate production. In conclusion, this study has shown that POS can have a beneficial effect on the fecal microflora; however, a classical prebiotic effect was not found. An increase in the Eubacterium rectale population was found, and butyrate levels increased, which is of potential benefit to the host.

Beverages↗
PubMed1980

[Influence of hydrothermic and enzymatic treatments on the nutritive value of Faba beans: in vitro study].

In order to improve the digestibility of the Faba bean flour an hydrothermic enzymic and fermentation treatment has been thought out (US patent 395 8015, Ets Ury, M. Gay). This study aims at stemming out the nutritionnal and structural repercusions of this treatment on the Faba proteins. The nitrogen distribution is deeply changed : total nitrogen increase (47%), water soluble nitrogen decrease (41%), water soluble non-protein nitrogen increase. The treatment can enrich the flour in nitrogen but the proteins supplement is insoluble in water. The treatment changed the electrophoretic behaviour of flour proteins letting disappear precipitable pH 4,5 proteins. Amino acid composition is slightly changed, however there is an increase of lysine and methionine (15 et 25%) and a decrease of cysteine (28%). The chemical score shows sulfur amino acids and tryptophan deficiency. Enzymatic (pepsine and pancreatine mixture) liberation of all amino acids is low and is not improved by the treatment but for the lysine. Cell proteins supplement, which appeared during the treatment (61%), water insoluble, could improve nutritive value of the flour if a more complete destruction of the cell walls permitted their liberation and their solubilization.

Amino Acids↗
PubMed2026

Functional and flavour-enhancing properties of Staphylococcus sp. from Napham.

Napham, traditional fermented food of the Bodo community in Assam, is produced from tender shoots of Colocasia esculenta and dried fish, and was recently granted Geographical Indication (GI) status. Despite its cultural and nutritional significance, its beneficial microbiota remains insufficiently characterized. This study aimed to identify multifunctional bacterial isolates with both functional and flavor-enhancing properties for use as starter cultures. Forty-eight isolates were screened for Gram reaction, enzymatic activities (protease, lipase, carbohydrate fermentation), and biosafety traits. Four isolates (NAP/1, NAP/2, NAP/3, NAP/4) exhibiting a preliminary phenotypic safety profile based on in vitro screening were evaluated for gastrointestinal stress tolerance traits, including tolerance to acid (pH 2.0), phenol (0.4%), salt (8% NaCl), as well as auto-aggregation capacity and adhesion to chicken crop epithelial cells. Among them, isolate NAP/4 exhibited comparatively higher tolerance, strong adhesion, and high auto-aggregation, and demonstrated a favorable in vitro safety profile, including &#x3b3;-hemolysis and broad antibiotic susceptibility. In curd and rice beverage models, NAP/4 enhanced sensory qualities and produced diverse flavor volatiles, supporting its candidacy as a multifunctional food-fermenting isolate prior to genomic validation. 16S rRNA sequencing revealed NAP/4 as Staphylococcus sp. (GenBank accession: PQ471484.1). Collectively, these findings highlight NAP/4 as a promising candidate for further genomic evaluation toward potential application in controlled fermentation systems and clean-label formulations. However, whole-genome sequencing and in vivo validation remain essential next steps to confirm safety and functional efficacy at the molecular level.

Journal Article↗
PubMed2005

Cofactor dependence in furan reduction by Saccharomyces cerevisiae in fermentation of acid-hydrolyzed lignocellulose.

A decreased fermentation rate due to inhibition is a significant problem for economic conversion of acid-pretreated lignocellulose hydrolysates to ethanol, since the inhibition gives rise to a requirement for separate detoxification steps. Together with acetic acid, the sugar degradation products furfural and 5-hydroxymethyl furfural are the inhibiting compounds found at the highest concentrations in hydrolysates. These aldehydes have been shown to affect both the specific growth rate and the rate of fermentation by yeast. Two strains of Saccharomyces cerevisiae with different abilities to ferment inhibiting hydrolysates were evaluated in fermentations of a dilute acid hydrolysate from spruce, and the reducing activities for furfural and 5-hydroxymethyl furfural were determined. Crude cell extracts of a hydrolysate-tolerant strain (TMB3000) converted both furfural and 5-hydroxymethyl furfural to the corresponding alcohol at a rate that was severalfold higher than the rate observed for cell extracts of a less tolerant strain (CBS 8066), thereby confirming that there is a correlation between the fermentation rate in a lignocellulosic hydrolysate and the bioconversion capacity of a strain. The in vitro NADH-dependent furfural reduction capacity of TMB3000 was three times higher than that of CBS 8066 (1,200 mU/mg protein and 370 mU/mg protein, respectively) in fed-batch experiments. Furthermore, the inhibitor-tolerant strain TMB3000 displayed a previously unknown NADH-dependent reducing activity for 5-hydroxymethyl furfural (400 mU/mg protein during fed-batch fermentation of hydrolysates). No corresponding activity was found in strain CBS 8066 (<2 mU/mg). The ability to reduce 5-hydroxymethyl furfural is an important characteristic for the development of yeast strains with increased tolerance to lignocellulosic hydrolysates.

Cellulose↗
PubMed2005

VSL#3 probiotic preparation has the capacity to hydrolyze gliadin polypeptides responsible for Celiac Sprue.

The native structure and distribution of gliadin epitopes responsible for Celiac Sprue (CS) may be influenced by cereal food processing. This work was aimed at showing the capacity of probiotic VSL#3 to decrease the toxicity of wheat flour during long-time fermentation. VSL#3 (10(9) cfu/ml) hydrolyzed completely the alpha2-gliadin-derived epitopes 62-75 and 33-mer (750 ppm). Two-dimensional electrophoresis, immunological (R5 antibody) and mass spectrometry analyses showed an almost complete degradation of gliadins during long-time fermentation of wheat flour by VSL#3. Gliadins non-hydrolyzed during fermentation by VSL#3 were subjected to peptic-tryptic (PT) digestion and analyzed by CapLC-ESI-Q-ToF-MS (Capillary Liquid Chromatography-Electrospray Ionization-Quadrupole-Time of Flight-Mass Spectrometry). Search for several epitopes showed the only presence of alpha2-gliadin-fragment 62-75 at a very low concentration (sub-ppm range). Compared to IEC-6 cells exposed to intact gliadins extracted from the chemically acidified dough (control), VSL#3 pre-digested gliadins caused a less pronounced reorganization of the intracellular F-actin which was mirrored by an attenuated effect on intestinal mucosa permeability. The release of zonulin from intestinal epithelial cells treated with gliadins was considerably lower when digested with VSL#3. Agglutination test on K 562 (S) cells showed that the PT-digest of wheat flour treated with VSL#3 increased the Minimal Agglutinating Activity of ca. 100 times. Wheat proteins were extracted from doughs and subjected to PT digestion. Compared to PT-digest from chemically acidified dough, celiac jejunal biopsies exposed to the PT-digest from the dough fermented by VSL#3 did not show an increase of the infiltration of CD3(+) intraepithelial lymphocytes. Proteolytic activity by probiotic VSL#3 may have an importance during food processing to produce pre-digested and tolerated gliadins for increasing the palatability of gluten-free products.

Actins↗
PubMed2001

Colonic metabolism of ranitidine: implications for its delivery and absorption.

The aim of this study was to assess the in vitro stability of ranitidine to colonic bacteria by utilising a batch culture fermentation system to simulate the conditions of the colon. Three quantities of ranitidine, 100, 200 and 500 mg, in the form of the hydrochloride salt, were introduced into individual 100 ml fermenters consisting of buffer medium inoculated with freshly voided human faeces (10% w/v). Control experiments were also run in parallel using equivalent drug quantities in buffer medium without the presence of faeces. Samples were removed at pre-determined time intervals over a 24 h period and were subsequently analysed by high-performance liquid chromatography (HPLC) for drug concentration. A selection of the samples removed from the fermenters was also analysed by conventional UV spectroscopy and mass spectrometry. Subsequent to an initial dissolution phase in the fermentation system, a marked decline in ranitidine concentration was noted over time, thereby suggesting degradation and metabolism of the drug by colonic bacteria. No such decline in concentration was noted in the control buffer systems. The rate and extent of metabolism was rapid and complete within 12 and 24 h for the 100 mg and 200 mg samples, respectively, although the largest sample size, 500 mg, was only partly metabolised over the course of the experiment. UV and mass spectrometry analysis indicated that metabolism occurred via cleavage of an N-oxide bond within the molecule with the resultant loss of an oxygen atom, although further metabolic reactions are possible. Such metabolism may in part be responsible for the poor bioavailability of ranitidine from the colon.

Absorption↗