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PubMed1986

In vitro activity of flurithromycin, a novel macrolide antibiotic.

Flurithromycin is an (8,S)-8-fluoroerythromycin isolated from the fermentation broth of Streptomyces erythraeus ATCC 31772, a blocked mutant of a strain producer of erythromycin. Its in vitro antibacterial activity has been determined on recent clinical isolates of respiratory pathogens. The range of MIC for Streptococcus pneumoniae and Streptococcus beta-haemolyticus group A is from 0.0015 to 0.006 microgram/ml, for Haemophilus influenzae from 0.012 to 0.4 microgram/ml, for Staphylococcus aureus from 0.1 to 3.1 micrograms/ml. Its action is bacteriostatic and increases at alkaline pH. Among anaerobes Clostridium perfringens, Bacteroides fragilis, other species of Bacteroides and Peptostreptococcus are particularly susceptible. Flurithromycin also showed some activity on Mycobacterium bovis, M. scrofulaceum and M. phley. The determination of killing curves indicated that in most cases a killing effect was obtained at 4 X MIC. A combination of flurithromycin with ampicillin or doxycycline sometimes was synergic, but more often additive and never antagonistic. The possible interference of flurithromycin on some parameters of the natural system of defense was determined. At concentrations equal to therapeutic levels in blood and tissues, flurithromycin did not influence chemotaxis, phagocytosis, metabolic activation and the killing activity of neutrophils.

Ampicillin↗

PubMed1997

Probiotic fermentation: effect on antinutrients and digestibility of starch and protein of indigenously developed food mixture.

An indigenously developed food mixture which contained huskless barley flour, green gram dhal flour, skimmed milk powder and tomato pulp ("BGMT" mixture) was autoclaved, cooled and fermented with L. acidophilus at 37 degrees C for 24 h at a dosage of 100,000 cells/ml. This process markedly reduced the phytic acid and polyphenol content and significantly improved the in vitro digestibility of starch and protein. Starch digestibility almost doubled in the fermented mixture. A significant negative relationship was obtained between the contents of antinutrients and digestibility.

Child↗

PubMed2003

Effect of natural and controlled fermentation on chemical composition and nutrient dialyzability from beans (Phaseolus vulgaris L.).

The effect of natural and controlled fermentation with an inoculum of Lactobacillus plantarum and additional thermal treatment (dry heat at 120 degrees C for 20 min) on the availability of N, P, Fe, Cu, Zn, Ca, and Mg from Phaseolus vulgaris L. var. carrilla was estimated using an in vitro method based on equilibrium dialysis. Natural and controlled fermentations caused significant reductions in the pH and phytate content (36%) of the bean flours, with a concomitant increase in the titratable acidity and free phosphorus content, and had no effect on the other nutrients studied. The percentage of dialyzable N, P, Cu, and Mg was significantly improved by both types of fermentation, whereas Zn dialyzability was significantly reduced. The greatest reduction was observed for the bean flour fermented with an inoculum of L. plantarum. The percentage of dialyzable Fe improved significantly as a result of natural fermentation but was not affected by controlled fermentation. The application of dry heat at 120 degrees C for 20 min caused a significant increase in Fe dialyzability and a further reduction in the percentage of dialyzable Zn in fermented bean flours but did not affect the dialyzability of the other nutrients studied.

Copper↗

PubMedDate not supplied

Nutritional and therapeutic aspects of fermented dairy products.

In summary, evaluation of the nutrient composition of fermented dairy foods indicates that, like milk, they are good sources of protein, calcium, riboflavin and vitamin B12. Fermented dairy foods are also a good source of folic acid due to microbial synthesis. The absorption of lactose in yogurt is enhanced by the presence of bacterial lactase. Like their nonfermented counterparts, fermented dairy foods may be chosen within a broad range of fat and calorie levels. Fermented and low fat milk products contain only forty to sixty-three calories per 100 grams, whereas sour cream, like sweet cream, is high in fat and contains over two hundred calories per 100 grams. Some fermented dairy foods have antibiotic or antitumor activity in vitro or in laboratory rats. The relevance of these findings to the treatment of human diseases is unknown.

Animals↗

PubMed2006

In vitro degradation of the flavonol quercetin and of quercetin glycosides in the porcine hindgut.

The present study investigated the microbial degradation of the plant flavonol quercetin and its naturally occurring glycosides isoquercitrin and rutin in the porcine hindgut. The experiments were carried out with the semicontinuous colon-simulation technique. The fluid and particle phase of pig hindgut contents from freshly slaughtered animals were used for the in vitro incubations. Following a five-day equilibration period, quercetin, isoquercitrin or rutin were administered to fermentation vessels and their turnover rate was determined. None of the flavonols affected parameters of microbial fermentation like pH, redox potential or VFA production. The turnover rate for isoquercitrin was seven times higher than the turnover for the fermentation fluid. The turnover rates for quercetin and rutin were four and twofold higher than fluid turnover, respectively. After administration of isoquercitrin or rutin, their aglycone quercetin was detected as an intermediary metabolite. Under sterile conditions using autoclaved incubation fluids and hindgut contents, turnover rates for quercetin and rutin were still higher than the fluid turnover in the fermentation vessels. This indicates a certain chemical instability of the flavonols and/or adsorption to ingesta particles. Thus, flavonols are subjected to microbial metabolism in the porcine hindgut. The glycosidic structure strongly influences the rate of metabolism.

Adsorption↗

PubMed2006

Production of lipopeptide antibiotic iturin A using soybean curd residue cultivated with Bacillus subtilis in solid-state fermentation.

Bacillus subtilis RB14-CS, which suppresses the growth of various plant pathogens in vitro by producing the lipopeptide antibiotic iturin A, was cultured using soybean curd residue, okara, a by-product of tofu manufacture in solid-state fermentation. After 4 days incubation, iturin A production reached 3,300 mg/kg wet solid material (14 g/kg dry solid material), which is approximately tenfold higher than that in submerged fermentation. When the okara product cultured with RB14-CS was introduced into soil infested with Rhizoctonia solani, which is a causal agent of damping-off of tomato, the disease occurrence was significantly suppressed. After 14 days, the number of RB14-CS cells remained in soil at the initial level, whereas almost no iturin A was detected in soil. As the okara cultured with RB14-CS exhibited functions of both plant disease suppression and nutritional effect on tomato seedlings, this product is expected to contribute to the recycling of the soybean curd residue.

Bacillus subtilis↗

PubMed2000

Optimization of the solid state fermentation process to obtain tempeh from hardened chickpeas (Cicer arietinum L.).

Solid state fermentation (SSF) represents a technological alternative for a great variety of cereals and legumes, or combination of them, to improve their nutritional quality and to obtain edible products with palatable sensorial characteristics. The objective of this work was to find the best conditions of fermentation temperature and time to obtain tempeh from hardened chickpeas (Cicer arietinum L.) applying SSF. Response surface methodology (RSM) was applied over three response variables (phytic acid, in vitro protein digestibility and available lysine) to find best conditions of fermentation to carry out the process. A central composite experimental design with two factors [X1 = temperature (31-36 degrees C) and X2 = time (48-72 h)] in five levels (2 factorials, 2 axial, I central) was used. Spores from Rhizopus stolonifer were suspended in distilled water (1 x 10(6) spores/mL) and used as starter. According to regression models, minimum and maximum levels of the response variables were 1.24-2.66 mg phytic acid/g of sample DM, 77.6-83.5% in vitro protein digestibility and 2.18-4.63 g available lysine/16 g N. The superposition of contour plots of each one of the response variables allowed researchers to find, graphically, the best conditions for the SSF process: 35.8 degrees C for 42.7 h.

Fabaceae↗

PubMed1978

Pilot-scale semisolid fermentation of straw.

Semisolid fermentation of ryegrass straw to increase its animal feed value was successfully performed on a pilot scale. The pilot plant, which could handle 100 kg of straw per batch, was designed so that all major operations could take place in one vessel. The straw was hydrolyzed at 121 degrees C for 30 min with 0.5 N H2SO4 (7:3 liquid:solid), treated with ammonia to raise the pH to 5.0, inoculated with Candida utilis, and fermented in a semisolid state (70% moisture). During fermentation the straw was held stationary with air blown up through it. Batch fermentation times were 12 to 29 h. Semisolid fermentation did not require agitation and supported abundant growth at 20 to 40 degrees C even at near zero oxygen tensions. Fermentation increased the protein content, crude fat content, and in vitro rumen digestibility of the straw.

Animal Feed↗

PubMed2006

Effect of isomalt consumption on faecal microflora and colonic metabolism in healthy volunteers.

Due to its low digestibility in the small intestine, a major fraction of the polyol isomalt reaches the colon. However, little is known about effects on the intestinal microflora. During two 4-week periods in a double-blind, placebo-controlled, cross-over design, nineteen healthy volunteers consumed a controlled basal diet enriched with either 30 g isomalt or 30 g sucrose daily. Stools were collected at the end of each test phase and various microbiological and luminal markers were analysed. Fermentation characteristics of isomalt were also investigated in vitro. Microbiological analyses of faecal samples indicated a shift of the gut flora towards an increase of bifidobacteria following consumption of the isomalt diet compared with the sucrose diet (P<0.05). During the isomalt phase, the activity of bacterial beta-glucosidase decreased (P<0.05) whereas beta-glucuronidase, sulfatase, nitroreductase and urease remained unchanged. Faecal polyamines were not different between test periods with the exception of cadaverine, which showed a trend towards a lower concentration following isomalt (P=0.055). Faecal SCFA, lactate, bile acids, neutral sterols, N, NH3, phenol and p-cresol were not affected by isomalt consumption. In vitro, isomalt was metabolized in several bifidobacteria strains and yielded high butyrate concentrations. Isomalt, which is used widely as a low-glycaemic and low-energy sweetener, has to be considered a prebiotic carbohydrate that might contribute to a healthy luminal environment of the colonic mucosa.

Adult↗

PubMed1992

In vitro and in vivo studies of factors affecting digestion of feeds in synthetic fiber bags.

Dry matter disappearance (DMD) and cellulose disappearance (CD) from alfalfa hay were measured simultaneously in synthetic fiber bags incubated in vitro. In general, DMD, CD, and pH were reduced (P less than .05) inside the bags compared with values in the fermentation flasks. Bags became fully expanded with gas soon after the fermentation started, which seemed to inhibit fluid movement into and out of the bag. By creating a vacuum in the flask, fluid exchange was enhanced, and DMD, CD, and pH increased (P less than .01) inside the bags. Sample size, type of fabric, and fabric pore size affected pH, DMD, and CD. Inoculum source (forage or concentrate diet) did not affect DMD in either bags or flasks. In contrast, DMD in bags incubated in vivo was affected (P less than .01) by animal diet. When bags were incubated in vivo inside a rigid plastic container, both pH and DMD were reduced (P less than .01) compared with bags suspended freely in the rumen. Direct physical action of ruminal contents on the bags apparently enhanced exchange of fluid. Bacterial concentrations in bags suspended freely in the rumen were greater than those in bags incubated inside containers. Synthetic fiber bags may be useful in comparing digestibility between diets; however, caution is needed in evaluating such data in absolute terms.

Animal Feed↗

PubMed2002

The antioxidant cocktail effective microorganism X (EM-X) inhibits oxidant-induced interleukin-8 release and the peroxidation of phospholipids in vitro.

The antioxidant beverage EM-X is derived from the ferment of unpolished rice, papaya, and sea-weeds with effective microorganisms. Oxidative stress enhances the expression of proinflammatory genes, causing the release of the chemokine interleukin-8 (IL-8), which mediates a multitude of inflammatory events. Human alveolar epithelial cells (A549) were treated with H(2)O(2) (100 microM) or TNF-alpha (10ng/ml) alone or with the addition of EM-X (100 microl/ml), incubated for 20h, and the release of IL-8, measured using ELISA. EM-X inhibited the release of IL-8 at the transcriptional level in A549 cells. EM-X also decreased the iron/ascorbate dependent peroxidation of ox-brain phospholipids in a concentration dependent manner. A TEAC value of 0.10+/-0.05mM was obtained for EM-X, indicating antioxidant potential. We suggest that the anti-inflammatory and antioxidant properties of EM-X are dependent on the flavonoid contents of the beverage.

Antioxidants↗

PubMed1995

A simple in vitro model for growth control of bacterial biofilms.

The perfused biofilm fermenter was found to be unsuitable for the long-term culture and growth rate control of Staphylococcus aureus and Pseudomonas aeruginosa biofilms. In a simplified approach, biofilms of these organisms were grown within Sorbarod filter plugs which were perfused with culture medium. Pseudo-steady states were established which were stable over several days at which the growth rate of the biofilm was reproducible, measurable and significantly slower than in broth culture. Environmental scanning electron microscopy of dissected Sorbarods demonstrated an association of cells with the surfaces of individual cellulose fibres, and growth characteristic of biofilms. Relatively high cell numbers recovered from the Sorbarod model facilitated biochemical investigations of biofilm populations and cells released spontaneously from them. SDS-PAGE demonstrated significant differences between the protein profiles of biofilm and eluted populations, which include, in Staph. aureus, the repression of a 48 kDa protein and increased expression of a 21 kDa protein relative to planktonic controls cultured at equivalent growth rates. The paper demonstrates the suitability of the approach for the culture of biofilm samples which are suitable for biochemical analysis.

Bacteriological Techniques↗

PubMed2002

Inhibitory effect of Lactobacillus acidophilus on Helicobacter pylori in peptic ulcer patients: in vitro study.

Lactobacillus acidophilus (L. acidophilus) have been introduced into many fermented dairy products. The presence of L. acidophilus appears to decrease Helicobacter pylori (H. pylori) density in the human stomach and could enhance antibiotic therapy for H. pylori eradication. This study was designed to determine the optimal density of L. acidophilus that has a maximum inhibitory effect on H. pylori in peptic ulcer patients. To determine whether L. acidophilus has an inhibitory effect on H. pylori isolated from peptic ulcer patients and to determine whether the optimal density of L. acidophilus has a maximum inhibitory effect on H. pylori isolated from peptic ulcer patients. H. pylori was isolated from gastric biopsy specimens of peptic ulcer patients. The suspension of pure H. pylori colonies were inoculated into the broth and adjusted to match the density of No.3 MacFarland standard (approximately 9x10(8) cells/ml). Forty microliters of the suspension were equally spread onto each quadrant of the plate and left to dry. L. acidophilus was prepared from LC-1 (Nestle Research Center, Switzerland). They were grown on blood agar and incubated overnight at 37 degrees C. The suspension of L. acidophilus was inoculated into the broth and adjusted to match the density of No.1, No.2, No.3 and No.4 MacFarland standard (approximately 3x10(8), 6x10(8), 9x10(8) and 12x10(8) cells/ml respectively). Ten microliters of each density of L. acidophilus was dropped onto each quadrant of a previously inoculated H. pylori plate and then the plate was kept under microaerophilic conditions for 72 hours. Inhibition clear halo zone of H. pylori around the colonies of L. acidophilus was interpreted as the inhibitory effect. H. pylori were isolated from gastric biopsy specimens of fifteen peptic ulcer patients (eleven patients with gastric ulcer and four patients with duodenal ulcer). A total of sixty tests of inhibitory effect of L. acidophilus on H. pylori were evaluated in the present study. L. acidophilus had inhibitory effect on H. pylori in 13/15 patients (86.67%) and L. acidophilus in the density of No.3 MacFarland standard had a significantly higher inhibitory effect on H. pylori in the density of No.3 MacFarland than that of No.1 (60% vs 20%; p<0.05), No.2 (60% vs 20%; p<0.05) and No.4 (60% vs 20%; p<0.05) MacFarland standard. In conclusion, L. acidophilus has an inhibitory effect on H. pylori isolated from peptic ulcer patients. Approximately an equal density of L. acidophilus on H. pylori has the most favorable effect. This optimal density of L. acidophilus should have maximum effect on H. pylori clearance and could enhance antibiotic therapy for H. pylori eradication in humans.

Adult↗

PubMedDate not supplied

[Enzymatic mechanisms of degradation of DNA replication forks in vitro].

The present work provides experimental evidence of two ways of fermentative degradation of DNA replication forks in vivo. The first way proceeds under the influence of exonuclease V, which degradates DNA replication forks, uncovered by singlestrand binding (ssb) proteins. DNA replication forks protected against nucleases by ssb protein are degrated by a second way: by tandem action of DNA polymerase II with ssb protein complexes and exonuclease V. The default of normal ssb protein in cells of Escherichia coli is responsible for the first way of DNA replication forks degradation. The second way is occurs at excess of normal ssb protein.

Bacterial Proteins↗

PubMed1996

In vitro determination of ruminal protein degradation using freeze-stored ruminal microorganisms.

Mixed ruminal microorganisms were harvested from a lactating dairy cow and preserved frozen or lyophilized. Fermentation characteristics of freshly strained ruminal fluid, frozen microorganisms, or lyophilized microorganisms were evaluated during a 24-h pre-incubation and a 4-h incubation with test proteins. Differences observed during the first 4 to 6 h in total amino acid concentration, optical density, pH and VFA concentrations, acetate:propionate ratio, and lactate concentration largely disappeared later in the pre-incubation. Protein degradation rates determined for expeller and solvent meals were .015 and .092 h-1, .015 and .101 h-1, and .005 and .019 h-1, with fresh ruminal fluid, frozen microorganisms, and lyophilized microorganisms, respectively. Regression of degradation rates obtained with fresh ruminal fluid on those obtained with pre-incubated, frozen microorganisms indicated the two methods were well correlated (r2 = .98 and .94 in two experiments). Mean in vitro degradability obtained for 17 feeds using pre-incubated, frozen microbes was 89% of that obtained using the in situ method; however, in situ degradation rates for these same feeds averaged only 67% of those obtained using frozen microorganisms. Ruminal undegraded protein values for nine samples of heated soybeans and soybean meal, determined using frozen microbes, were overestimated relative to in vivo values (in vivo = 1.1 + .8 in vitro; r2 = .77). These results indicated that ruminal microorganisms can be preserved by freezing and used as the inoculum for in vitro determination of ruminal protein degradation after overnight pre-incubation.

Acetates↗

PubMed2006

Evaluation of the simultaneous effects of processing parameters on the iron and zinc solubility of infant sorghum porridge by response surface methodology.

The purpose of this study was to improve the micronutrient quality of indigenous African infant flour using traditional techniques available in the region. Response surface methodology was used to study the effect of duration of soaking, germination, and fermentation on phytate and phenolic compounds (PC), pH, viscosity, and the in vitro solubility (IVS) of iron and zinc in infant sorghum flour. The phytate and the PC concentrations of the flour were significantly modified as a result of the duration of germination and fermentation and their mutual interaction. These modifications were accompanied by a significant increase in % IVS Zn after 24 h of sprouting. Except for the interaction of soaking and fermentation, none of the processing parameters exerted a significant effect on the % IVS Fe. The viscosity of the porridge prepared with the flour decreased significantly with the duration of germination, making it possible to produce a porridge with high energy and nutrient density. The use of germination in combination with fermentation is recommended in the processing of cereals for infant feeding in developing countries.

Digestion↗

PubMed2002

Production of amines in equine cecal contents in an in vitro model of carbohydrate overload.

Acute laminitis can be induced experimentally in horses by the administration of carbohydrate, resulting in fermentation within the cecum and ischemia-reperfusion of the digits. The products of fermentation that trigger acute laminitis are as yet unknown; however, compounds such as amines might play a role due to their potential vasoactive properties. The objectives of this study were to quantify the amines present in equine cecal contents and to use a model of carbohydrate overload in vitro to test the hypothesis that carbohydrate fermentation is associated with increased amine production. Cecal contents from each horse were divided into aliquots and incubated anaerobically with either cornstarch or inulin (a form of fructan carbohydrate; both 1 g/100 mL). The pH was measured and samples were taken at the same time for amine measurement by HPLC at 2-h intervals over a 24-h period. In a second set of experiments, the effects of the antibiotic virginiamycin (1 mg/100 mL), calcium (CaPO4; 0.3 g/100 mL), and plant steroidal saponin (Yucca schidigera extract; 0.1 g/100 mL) were examined on pH and amine concentrations in cecal contents incubated with starch or inulin. Both starch and inulin caused significant time-dependent falls in pH, from 6.7 +/- 0.1 at 0 h to 5.2 +/- 0.1 (starch) and 5.0 +/- 0.1 (inulin) at 24 h. Fermentation of carbohydrate was also associated with increased production of phenylethylamine and isoamylamine (two- to threefold increases) as well as putrescine and cadaverine (1.5- to twofold increases). Virginiamycin inhibited the fall in pH and increases in production of phenylethylamine and isoamylamine, while calcium phosphate moderated the changes in pH only. Yucca schidigera extract was without effect. These data show that fermentation of carbohydrate by equine cecal microbiota may lead to increased production of amines.

Acute Disease↗

PubMed2002

Effects of feeding diets based on silage from corn hybrids that differed in concentration and in vitro digestibility of neutral detergent fiber to dairy cows.

A dual-purpose hybrid and a hybrid selected for high neutral detergent fiber (NDF) concentration were harvested as corn silage. The dual-purpose silage (DPCS) had 42% NDF and 35.4% in vitro (30 h) NDF digestibility and the high fiber silage (HFCS) had 49% NDF and 40.1% in vitro NDF digestibility. Two diets (dry matter basis) had 45% DPCS or HFCS and 46% corn grain-based concentrate (dietary NDF was 29 and 32%, respectively), a third diet had 33% HFCS and 58% corn-based concentrate (27% dietary NDF), and a fourth diet had 33% DPCS and 58% concentrate that contained soybean hulls (32% dietary NDF). All diets contained 9% alfalfa silage. Diets were fed to eight midlactation Holstein cows in a 4 x 4 Latin square with 28 d periods. No differences among treatments were observed for milk yield (34.1 kg/d), dry matter intake (23.7 kg/d), and yield and concentration of milk protein. Cows fed the diet with 33% HFCS tended to have lower milk fat percentage than cows fed the 45% DPCS diet. Total digestible nutrients (measured using total collection) tended to be lower for the 33% DPCS diet than for the 45% DPCS diet. In vivo digestibility of NDF tended to be lower for the 33% HFCS diet than the 45% DPCS diet, but digestibility of starch in the two diets with HFCS was higher than the 45% DPCS diet. The lack of any substantial differences in responses suggest that the HFCS was equal to the DPCS when fed at 45% of the diet dry matter (53.5% total forage). When HFCS replaced DPCS so that NDF was similar between diets, milk fat percentage was reduced and ruminal propionate was increased. Increasing dietary NDF by adding soybean hulls to a diet based on DPCS reduced digestibility of dry matter, organic matter, and protein, and resulted in lower energy balance than the 45% DPCS diet.

Animals↗