[A new therapy of intestinal helminthiasis by nematodes: in vitro experience with the proteolytic ferment papain].
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Animals↗
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Results for “In vitro fermentation”
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Human faecal microbiota develops the ability to degrade type 3 resistant starch during weaning.
BACKGROUND: Colonisation of the human colon starts immediately after birth. Bacterial composition is substantially influenced by the type of feeding. During weaning, microbiota diversifies considerably to finally approach the composition of that of adults. The aim of this study was to investigate the ability of colonic microbiota obtained from different age groups to ferment resistant starch (RS). METHODS: Faecal samples of breast-fed and formula-fed infants, infants at weaning, adults and elderly subjects were used as inocula. Fermentation experiments were performed by applying a standardised in vitro batch method. Fermentability was established by measuring both metabolite production and substrate degradation. An RS type 3 (RS-3) was used as substrate; its behaviour was compared with that of lactulose (positive control), whereas inoculum without substrate was used as negative control. RESULTS: Overall fermentation patterns clearly showed that the human microbiota of all age groups is able to degrade lactulose. In contrast, RS-3 was found resistant to the attack by microbiota of both breast-fed and formula-fed infants. Bacteria collected from infants at weaning were able to degrade RS-3 completely, but slower compared with adults. With increasing age, RS-3 fermentation was observed to be slightly retarded again. CONCLUSIONS: Human faecal microbiota of all age groups is able to ferment lactulose in vitro quickly and completely. The ability to degrade RS-3, however, is only established during weaning. Whether fermentation-related production of short-chain fatty acids from RS-3 and concurrent modifications of the microbiota can result in potential health benefits to the host at this stage of life needs to be elucidated.
Adult↗
Effect of gluconic acid on piglet growth performance, intestinal microflora, and intestinal wall morphology.
Gluconic acid (GA) derives from the incomplete oxidation of glucose by some Gluconobacter strains. When fed to nonruminant animals, GA is only poorly absorbed in the small intestine and is primarly fermented to butyric acid in the lower gut. This study investigated the effect of GA on in vitro growth response and metabolism of swine cecal microflora and on animal growth performance, intestinal wall morphology, and intestinal microflora. During a 24-h in vitro cecal fermentation, total gas production and maximum rate of gas production were increased by GA (linear, P < 0.001). Ammonia in cecal liquor was reduced by GA after 4, 8, and 24 h of fermentation (quadratic, P < 0.01). After 24 h of fermentation, total short-chain fatty acids, acetic acid, propionic acid, n-butyric acid, acetic to propionic acid ratio, and acetic + butyric to propionic acid ratio were linearly increased by GA (P < 0.001). In the in vivo study, 48 piglets were divided into 4 groups and housed in individual cages for 6 wk. Piglets received a basal diet with a) no addition (control) or with GA addition at b) 3,000 ppm, c) 6,000 ppm, or d) 12,000 ppm. After 6 wk, 4 animals per treatment were killed, and samples of intestinal content and mucosa were collected. Compared with control, GA tended to increase average daily gain (+13 and +14% for GA at 3,000 and 6,000 ppm, respectively; P of the model = 0.11; quadratic, P < 0.05). Daily feed consumption and gain to feed ratio were not influenced by GA. Intestinal counts of clostridia, enterobacteriaceae, and lactic acid bacteria were not affected by GA. Gluconic acid tended to increase total short-chain fatty acids in the jejunum (+174, +87, and +74% for GA at 3,000, 6,000, and 12,000 ppm, respectively; P of the model = 0.07; quadratic, P = 0.07). Morphological evaluation of intestinal mucosa from jejunum, ileum, and cecum did not show any significant differences among treatments. This study showed that feeding GA influences the composition and activity of the intestinal microflora and may improve growth performance of piglets after weaning.
Ammonia↗
Effects of animal or plant protein diets on cecal fermentation in guinea pigs (Cavia porcellus), rats (Rattus norvegicus) and chicks (Gallus gallus domesticus).
Monogastric herbivores such as the guinea pig depend on energy supply from enteric fermentation as short-chain fatty acids (SCFA) corresponding to 30-40% of their maintenance energy requirements. They evolved specific digestive system to adapt their indigenous microflora to plant polysaccharides fermentation. No information has been available about the adaptability of microbial fermentation in hindgut of the monogastric herbivorous to an animal protein diet. We investigated if the guinea pig can fully retrieve energy of an animal protein diet by hindgut fermentation compared with a plant protein diet. For comparison, we also studied two omnivores. End products of in vitro cecal fermentation (SCFA, ammonia and gases) were measured to judge how well an animal protein diet could be fermented. The animal protein diet resulted in the less intensive fermentation with increased feed intake and volume of cecal contents than the plant protein diet only in guinea pigs. This may be due to a limited capacity of the hindgut microflora to adapt to the substrate rich in animal protein. We also found that chick cecal contents produced methane at higher emission rate than ruminants.
Animals↗
Comparison of types of fermentation vessels for an in vitro artificial rumen procedure.
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Animal Feed↗
Developing a quantitative approach for determining the in vitro prebiotic potential of dietary oligosaccharides.
Prebiotics are nondigestible carbohydrates that beneficially affect the host by selectively stimulating the growth and/or activity of one, or a limited number of, bacteria present in the colon. The selected genera should have the capacity to improve host health (e.g. Bifidobacterium, Lactobacillus). To help identify preferred types, for inclusion into the diet, a quantitative equation [measure of the prebiotic effect (MPE)] is suggested. This will help evaluate, in vitro, the fermentation of dietary carbohydrates and compare their prebiotic effect. Although the approach is not meant to define health values, it is formulated to better inform the choice of prebiotic. It therefore, compares measurements of bacterial changes through the determination of maximum growth rates of predominant groups present in faeces, rate of substrate assimilation and the production of lactic, acetic, propionic and butyric acids. The equation will allow further in vitro comparisons of MPE, leading towards further studies (e.g. in humans) to determine the success of dietary intervention.
Acetate-CoA Ligase↗
In vitro metabolism of anthocyanins by human gut microflora.
BACKGROUND: Only a small part of the dietary anthocyanins are absorbed. Thus large amounts of the ingested compounds are likely to enter the colon. In vitro and in vivo studies have shown that colonic bacteria transform various flavonoids to smaller phenolic acids. However, there is very little information on bacterial transformations of anthocyanins. AIM OF THE STUDY: was to explore if anthocyanin glycosides were deglycosylated,whether the resulting aglycones were degraded further to smaller phenolic compounds by colonic bacteria, and to characterise metabolites. METHODS: Isolated cyanidin-3-glucoside and -rutinoside were fermented in vitro using human faecal microbiota as an inoculum. Metabolites were analysed and characterised by HPLC-DAS and LC-MS. They were identified by comparing their characteristics with those of available standards, and semi-quantified using the amount of substrate analysed from samples at initial timepoint. RESULTS: Cyanidin-3-glucoside and cyanidin aglycone could be identified as intermediary metabolites of cyanidin-3-rutinoside. At early timepoints (before 2 h), the formation of protocatechuic acid as a major metabolite for both cyanidin glycosides and detection of lower molecular weight metabolites show that anthocyanins were converted by gut microflora. Furthermore, reconjugation of the aglycone with other groups, non-typical for dietary anthocyanins, was evident at the later (after 2h) timepoints. CONCLUSION: Bacterial metabolism of anthocyanins involves the cleavage of glycosidic linkages and breakdown of the anthocyanidin heterocycle.
Anthocyanins↗
The effect of preservation method on the neutral detergent soluble fraction of forages.
Fermentation of neutral detergent solubles (NDS) was assessed using a 3 x 3 x 3 factorial arrangement. Three forage species (alfalfa, bromegrass, and orchardgrass) were collected at three maturities and preserved either by freeze drying, oven drying at 50 degrees C, or by ensiling. Each feed sample and its isolated NDF were fermented in vitro and gas production was monitored. Gas yield from NDS was determined as the difference between gas from the unfractionated forage and from its respective NDF. The forages ranged from 23 (immature alfalfa) to 68% NDF (mature orchardgrass). The silages were well fermented with a final pH of < or = 4.5. Increasing maturity decreased the final gas volume but did not change the rate of gas production from the NDS fraction. There was little difference in gas production between freeze-dried and oven-dried forage samples. Ensiling decreased gas yield from the unfractionated forage. The rate of gas production from the NDS fraction of the ensiled forages decreased an average of .05 h-1 compared with the freeze-dried sample. Gas yield from the NDS fraction decreased (from the freeze-dried sample) between 7 and 36% upon ensiling. The curve substraction approach can be used to evaluate the effects of ensiling on the neutral detergent-soluble fraction of forages.
Animals↗
Effect of fermentation on sorghum protein fractions and in vitro protein digestibility.
Changes in pH, titratable acidity, total soluble solids and proteins of Dabar sorghum (Sorghum bicolor (Linn) Moench.) during natural fermentation at 37 degreesC for up to 36 h were monitored. The pH of the fermenting material decreased sharply with a concomitant increase in the titratable acidity. Total soluble solids increased with progressive fermentation time. The crude protein and non-protein nitrogen slightly increased during the last stages of fermentation. The in vitro protein digestibility markedly increased as a result of fermentation. The globulin plus albumin fractions increased significantly (p < or = 0.05) during the first 8 h of fermentation. Kaffirin fraction decreased during the first 8 h of fermentation but increased sharply as fermentation progressed. Cross-linked kaffirins fluctuated during the fermentation process. Glutelin like protein, which was the minor fraction, true glutelins, the second most abundant fraction, together with non-extractable proteins fluctuated during the fermentation process.
Albumins↗
Effect of lasalocid, monensin and thiopeptin on rumen protozoa.
The effects of lasalocid, monensin and thiopeptin on the total number and the generic composition of rumen protozoa were determined in vivo and in vitro. Feeding lasalocid or monensin to cattle on either high grain or high roughage diets reduced total protozoal counts. Addition of lasalocid or monensin (6 to 48 micrograms ml-1) to the in vitro rumen fermentation resulted in marked reduction in protozoal numbers. The inhibition was dose dependent. Thiopeptin had no effect on rumen protozoa either in vivo or in vitro. Among the protozoal types, holotrichs (Dasytricha, Isotricha and Charonina) were unaffected by either lasalocid or monensin. Among the entodiniomorphs, Entodinium, Diplodinium and Ophryoscolex were more sensitive than the other types. Ophryoscolex purkynei was more sensitive to monensin than to lasalocid. Protozoal inhibition by lasalocid and monensin was transient because prolonged antibiotic feeding resulted in the selection of a resistant population in the rumen of cattle.
Animals↗
Increasing the intestinal resistance of rats to the invasive pathogen Salmonella enteritidis: additive effects of dietary lactulose and calcium.
BACKGROUND AND AIMS: Lactulose fermentation by the intestinal microflora acidifies the gut contents, resulting in an increased resistance to colonisation by acid sensitive pathogens. The extent of fermentation should be controlled to prevent acid induced epithelial cell damage. Considering the buffering capacity of calcium phosphate and its intestinal cytoprotective effects, whether supplemental calcium phosphate adds to the increased resistance to intestinal infections by lactulose fermentations was studied. METHODS: In a strictly controlled experiment, rats were fed a purified low calcium control diet, a low calcium/lactulose diet, or a high calcium/lactulose diet, and subsequently infected orally with Salmonella enteritidis. RESULTS: Lactulose fermentation lowered the pH and increased the lactic acid concentration of the intestinal contents, which significantly reduced excretion of this pathogen in faeces; thus it improved the resistance to colonisation. This agreed with the high sensitivity of S enteritidis to lactic acid (main metabolite of lactulose fermentation) in vitro. Calcium phosphate decreased translocation of S enteritidis to the systemic circulation, an effect independent of lactulose. The unfavourable increased cytotoxicity of faecal water caused by lactulose fermentation was more than counteracted by supplemental calcium phosphate. Moreover, calcium phosphate stimulated lactulose fermentation, as judged by the reduced lactulose excretion in faeces and increased lactic acid, ammonia, and faecal nitrogen excretion. CONCLUSION: Extra calcium phosphate added to a lactulose diet improves the resistance to colonisation and translocation of S enteritidis. This is probably mediated by a calcium induced stimulation of lactulose fermentation by the intestinal microflora and reversion of the lactulose mediated increased luminal cytotoxicity, which reduces damage inflicted on the intestinal mucosa.
Animals↗
Physiological effects of sucrose substitutes and artificial sweeteners on growth pattern and acid production of glucose-grown Streptococcus mutans strains in vitro.
The synergistic effects of four sucrose substitutes, polysorbate and five artificial sweeteners were studied in vitro on growth pattern and acid production of seven glucose-grown Streptococcus mutans strains, representing the five serological groups after Bratthall. Four distinct growth patterns during glucose fermentation were observed: high rate of growth with low acid production, moderate growth rate with moderate acid production, moderate growth rate with high acid production, and slow rate of growth with moderate acid production. Depending on the strain used, the final OD at 546 nm ranged from 0.55 to 0.99 and the final pH of the medium varied between 4.65 and 4.15. While added sucrose substitutes, with exceptions, usually enhanced growth rate, most artificial sweeteners suppressed or, at higher concentrations, even inhibited growth of S. mutans; addition of polysorbate to the medium always increased growth rate of S. mutans significantly. The presence of sucrose substitutes during glucose fermentation had no effect on final pH of the medium, but addition of artificial sweeteners, especially sodium saccharin, elevated final pH up to 1.8 units. The observed physiological patterns and differences within the several strains of S. mutans during glucose fermentation in vitro do not necessarily relate to the five serological groups of the species.
Fructose↗
Effects of different spices used in production of fermented sausages on growth of and curvacin A production by Lactobacillus curvatus LTH 1174.
Lactobacillus curvatus LTH 1174, a fermented sausage isolate, produces the listericidal bacteriocin curvacin A. The effect of different spices relevant for the production of fermented sausages was investigated in vitro through laboratory fermentations with a meat simulation medium and an imposed pH profile relevant for Belgian-type fermented sausages. The influence on the growth characteristics and especially on the kinetics of curvacin A production with L. curvatus LTH 1174 was evaluated. Pepper, nutmeg, rosemary, mace, and garlic all decreased the maximum specific growth rate, while paprika was the only spice that increased it. The effect on the lag phase was minor except for nutmeg and especially for garlic, which increased it, yet garlic was stimulatory for biomass production. The maximum attainable biomass concentration (X(max)) was severely decreased by the addition of 0.40% (wt/vol) nutmeg, while 0.35% (wt/vol) garlic or 0.80% (wt/vol) white pepper increased X(max). Nutmeg decreased both growth and bacteriocin production considerably. Garlic was the only spice enhancing specific bacteriocin production, resulting in higher bacteriocin activity in the cell-free culture supernatant. Finally, lactic acid production was stimulated by the addition of pepper, and this was not due to the manganese present because an amount of manganese that was not growth limiting was added to the growth medium. Addition of spices to the sausage mixture is clearly a factor that will influence the effectiveness of bacteriocinogenic starter cultures in fermented-sausage manufacturing.
Animals↗
Fruit and vegetable fiber fermentation by gut microflora from canines.
The objective of this study was to assess fermentability by canine gut microflora to include shortchain fatty acid (SCFA) production, organic matter (OM) disappearance, and gas production of vegetable and fruit fiber sources compared to fiber standards (psyllium, citrus pectin, and Solka Floc). Fiber sources included apple pomace, carrot pomace, flaxseed, fruit blend (mixture of peach, almond, nectarine, and plum), grape pomace, pea hulls, pistachio, and tomato pomace. Substrates were fermented in vitro for 4, 12, and 24 h with fecal flora obtained from three healthy dogs. Citrus pectin had the highest OM disappearance, SCFA production, and gas production at all times of fermentation; psyllium was intermediate and Solka Floc was lowest. A wide variation in fermentability was noted among the vegetable and fruit fiber sources. Apple pomace, carrot pomace, and flaxseed had the greatest fermentability as assessed by OM disappearance. Pea hulls and tomato pomace had intermediate OM disappearances, and fruit blend, grape pomace, and pistachio were poorly fermented. Carrot pomace produced the largest amounts of gas and SCFA. Apple pomace produced high concentrations of gas but intermediate concentrations of SCFA. Pea hulls and tomato pomace produced intermediate concentrations of gas and SCFA, whereas flaxseed, fruit blend, grape pomace, and pistachio produced low amounts of these fermentation products. For all substrates collectively, OM disappearance was highly correlated with both gas production (r2 = 0.782 and 0.723 for 12- and 24-h values, respectively) and SCFA production (r2 = 0.737 and 0.738 for 12- and 24-h values, respectively). In general, OM disappearance, gas production, and SCFA production were related to the insoluble:soluble fiber ratio in the samples; as the insoluble:soluble ratio decreased (increased soluble fiber), the OM disappearance, gas production, and SCFA production increased.
Animal Feed↗
The degradability characteristics of fifty-four roughages and roughage neutral-detergent fibres as described by in vitro gas production and their relationship to voluntary feed intake.
Fifty-four roughages of known voluntary dry-matter intakes (DMI; range 7.8-35.2 g/kg live weight per d) were examined in vitro in a gas production test. Samples (200 mg) of roughage and roughage neutral-detergent fibre (NDF) respectively were incubated in a mixed suspension of rumen contents for 96 h and the gas volumes recorded after 4, 6, 8, 12, 24, 30, 36, 48, 54, 60 and 96 h. The kinetics of gas production were derived from the volume recordings described by the exponential equation Y = A + B(l-e-ct) where A is the intercept and ideally reflects the fermentation of the soluble and readily available fraction of the feed, B describes the fermentation of the insoluble (but with time fermentable) fraction and c the fractional rate at which B is fermented per h; A + B describes total fermentation. In vitro true dry matter (TD) and NDF degradabilities (NDF-D) after 24 h incubation were also determined. Of the variation in DMI, 75% was accounted for by the in vitro gas production parameters A, B and c in stepwise multiple regressions; 82% of the variation in DMI was explained by the parameters (ANDF + BNDF) and cNDF as obtained from the incubation of roughage NDF. The rate constants (c) were less important than parameters related to the extent of gas production, accounting for only 6.5 (whole roughage) and 4.1% (NDF) of the variation in DMI. There was no statistical advantage in the use of the exponential model describing extent and rate of fermentation over some of the simple gas volume measurements: 75% of the variation in DMI was accounted for by in vitro gas production of whole roughage after 8 h of incubation. On average gas production from NDF measured from 24-96 h accounted for 81% of the variation in DMI. A combination of gas volume measurements after a short period of incubation (4-8 h) with a concomitant determination of NDF-D after many hours (> or = 24 h) can render NDF preparations and long incubation times redundant. A method is suggested to obtain two results for DMI prediction in one single incubation. Of the variation in DMI 80% was accounted for by the incubation of 500 mg whole roughage when incubation was terminated after 24 h and the residual undegraded substrate quantified.
Animal Feed↗
[Saponins in nutrition of swine, poultry and ruminants].
Saponins are glycosides found in many plants, which have soap character due to their surfactant properties. They work haemolytic and may cause symptoms of intoxication in high concentration. Among therapeutically relevant effects expectorative, anti-inflammatory and immune-stimulating effects have the highest ranking. Beyond that, saponins demonstrate antimicrobial properties particularly against fungi and additionally against bacteria and protozoa. In animal nutrition additions of saponins can suppress intestinal and ruminal ammonia production. The ammonia-reducing effect is primarily attributed to an inhibition of proteolytic microorganisms. Due to reduced NH3-concentrations metabolism is relieved, which offers benefits to animal welfare and animal performance. Accordingly improved feed convertion ratio can be registered in weanling and growing-finishing pigs with the employment of saponin-containing feed additives. With regard to ruminal fermentation in vitro and in vivo studies have shown that beside proteolytic protozoa also cellolytic and amylolytic bacterial species are restrained. To what extent antimicrobial activity supress digestion or whether the selective effects on microorganisms can be used purposefully to manipulate ruminal fermentation, must be clarified in further investigations.
Animal Feed↗
Adaptation of an in vitro system to the study of starch fermentation by rumen bacteria.
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Animals↗
In vitro gas production as a surrogate measure of the fermentability of cellulosic biomass to ethanol.
Current methods for measuring ethanol yields from lignocellulosic biomass are relatively slow and are not well geared for analyzing large numbers of samples generated by feedstock management and breeding research. The objective of this study was to determine if an in vitro ruminal fermentation assay used in forage quality research was predictive of results obtained using a conventional biomass-to-ethanol conversion assay. In the conventional assay, herbaceous biomass samples were converted to ethanol by Saccharomyces cerevisiae cultures in the presence of cellulase enzymes. Cultures were grown in sealed serum bottles and gas production monitored by measuring increasing head space pressure. Gas accumulation as calculated from the pressure measurements was highly correlated (r(2)>0.9) with ethanol production measured by gas chromatography at 24 h or 7 days. The same feedstocks were also analyzed by in vitro ruminal digestion, as also measured by gas accumulation. Good correlations (r(2) approximately 0.63-0.82) were observed between ethanol production during simultaneous saccharification and fermentation and gas accumulation in parallel in vitro ruminal fermentations. Because the in vitro ruminal fermentation assay can be performed without sterilization of the medium and does not require aseptic conditions, this assay may be useful for biomass feedstock agronomic and breeding research.
Biotechnology↗