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PubMedDate not supplied

Survival of Brucella abortus in milk fermented with a yoghurt starter culture.

In countries such as Mexico, brucellosis is still an important public health problem due to the consumption of non-pasteurized milk and dairy products, contaminated with Brucella spp. The aim of this study was to look into the survival of Brucella abortus during fermentation of milk with a yoghurt starter culture and storage at refrigeration temperature. Sterile skim milk was inoculated with B. abortus at two concentrations, 10(5) and 10(8) CFU/ml simultaneously with a yoghurt starter culture of lactic acid bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii subspecie bulgaricus). Inoculated flasks were incubated at 42 degrees C, followed by refrigeration at 4 degrees C. Samples were taken during fermentation and during storage and viable count of B. abortus and lactic acid bacteria and pH were determined. Results showed that after 10 days of storage at 4 degrees C, B. abortus was recovered in fermented milk at a level of 10(5) CFU/ml, despite the low pH below 4.0. Therefore B. abortus is able to survive in fermented milk. This finding may imply that non-pasteurized fermented milk contaminated with Brucella abortus could be a means of transmission of these bacteria.

Animals↗
PubMed1991

[The effect of monensin on the fermentation of feed with different proportions of hay and concentrate in an artificial rumen (rumen simulation technic)].

An experiment was conducted with rumen pouch (RUSITEC--Rumen Simulation Technique). In four fermentation vessels (V), percent proportions of hay and barley were as follows: V1--40:60, V2 - 60:40, V3--80:20 and V4--100:0. Every day 5 mg of monensin dissolved in 1 ml 96% ethanol were added to each fermentation vessel. All diets were isonitrogenous, and after an addition of urea the crude protein (CP) content made 13% in each diet. The experiment lasted 12 days: so called steady state period took the first six days when the fermentation conditions were stabilized. Monensin reduced dry matter digestibility, production of total volatile fatty acids, acetic acid, n-butyric and isovaleric acids and acetate: propionate proportion, and it increased the production of propionic and n-valeric acids. The production of methane and CO2 decreased. The higher proportion of hay in diets decreased dry matter digestibility, digestibility of detergent fibre, total and individual volatile fatty acids, CO2, methane energy yield of volatile fatty acids (E), glucose utilization, production of adenosine triphosphate and production of fermented hexoses. The production, utilization and recovery of metabolic hydrogen also decreased. The effectiveness of microbial matter synthesis (YATP = 11.3) was highest during the fermentation of feed containing 60% hay and 40% barley.

Animal Feed↗
PubMed1990

[Correlations between lactose-fermenting capacity, sensitivity to antibiotics and bacteriophage types of Salmonella agona strains].

Correlation between the ability to ferment lactose, sensitivity to chemotherapeutic agents and phage type of lactose fermenting and nonfermenting S. agona strains was shown in this study. The difference in sensitivity of two S. agona variants toward gentamicin, tobramycin and chloramphenicol was shown. Lactose fermenting S. agona strains were resistant to the above listed antibiotics. The percentage of the resistant strains was 95.3%, 96.9% and 95.3%, respectively. S. agona strains typable by biochemical tests were more often sensitive to those antibiotics. The percentage of the resistant strains of S. agona with typical biochemical properties was for gentamicin 19.4%, tobramycin 3.7% and chloramphenicol 6.7%. Moreover, the percentage of lactose fermenting S. agona strains resistant to seven other out of seventeen tested antibiotics was 83.8% on average and it was 20% higher than percentage of biochemically typical S. agona strains resistant to the same antibiotics. Lactose fermenting S. agona strains belonged almost four times more frequently to subtype VB and also more often to phage type XI; on the other hand six times rare to phage type I in comparison to biochemically typical S. agona strains.

Anti-Bacterial Agents↗
PubMed1989

Digestion, absorption, and fermentation of carbohydrates.

Newborn infants born after a term gestation appear to have an adequate capacity for small intestinal digestion and absorption of carbohydrate. Premature infants do not have a mature level of intestinal lactase activity. Apparently, in the premature infant, colonic fermentation serves an important, if not the only major route, for lactose carbon absorption, and it also appears that signs of fermentation activity such as increased BH2 are not indicative of disease. Important questions remaining in the premature infant relate to developmental aspects of colonic fermentative activity, effects of systemic antibiotic treatment on colonic salvage, the effects of various fermentation pathways on energy balance, the capacity for absorption of sugars, SCFA, and electrolytes by colonic epithelia, and the effects of fermentation products on metabolism and on the mucosal cells of the intestine or colon. Research addressing these questions may have relevance in the following areas: further development of formula diets for healthy premature infants and for patients of all ages with intestinal or colon dysfunction; the effects of colonic disease or surgical resection; the nutritional or clinical effects of dietary fiber; and the effects of antibiotic therapy on intestinal and colon function.

Animals↗
PubMed1989

Consumption of fermented milk products and breast cancer: a case-control study in The Netherlands.

In a case-control study in The Netherlands, we observed a significantly lower consumption of fermented milk products (predominantly yogurt and buttermilk) among 133 incident breast cancer cases as compared to 289 population controls (mean +/- SD among users only, 116 +/- 100 versus 157 +/- 144 g/day; P less than 0.01). The age-adjusted odds ratio of daily consumption of 1.5 glasses (greater than or equal to 225 g) of fermented milk versus none was 0.50 (95% confidence interval, 0.23-1.08). When fermented milk was entered as a continuous variable (per g) in either age-adjusted or multivariate analysis, the odds ratio expressed per 225 g was 0.63 (multivariate-adjusted 95% confidence interval, 0.41-0.96). After multivariate adjustment for intake of fat and other confounders, a statistically significant decrease in breast cancer risk was also observed for increasing intake of Gouda cheese. The multivariate-adjusted odds ratio expressed per 60 g of this fermented product was 0.56 (95% confidence interval, 0.33-0.95). For daily intake of milk, no statistically significant differences were observed between cases and controls. These results support the hypothesis that high consumption of fermented milk products may protect against breast cancer.

Animals↗
PubMed1988

[Stability of Shigella flexneri attenuated strain 2A 77 ADE- RIF-r after cultivation in a fermenter and lyophilization].

The method for the cultivation of S. flexneri attenuated strain 2a 77 ade- rifr in a fermenter with the use of casein fermentative broth containing 200-250 mg% of amino nitrogen has been developed. No changes in the properties of the initial strain have been found after its cultivation in a fermenter or after the lyophilization of the cultures grown in a fermenter. After cultivation in casein fermentative broth with 100 mg% of amino nitrogen the presence of S-R dissociation has been established, the S colonies having the properties of the initial strain. The reversion of the R colonies to prototrophism in adenine and differences in the level of their resistance to rifampicin are observed. The study of the plasmid profile of the initial strain and its ade+ revertants has revealed the disappearance of plasmids with a molecular weight of 140 MD in these revertants. All clones under study (ade+ and ade-) show negative results in the keratoconjunctival test. The conditions of cultivation and the causes of reversion are discussed.

Fermentation↗
PubMed1986

[Production of ethanol by fermentation with a high concentration of yeasts. Its application in already installed distilleries].

Due to the dramatic increase in international oil prices, the ethanol production by fermentation is presently becoming an attractive and feasible project for many countries Argentina has implemented an experimental national program of ethanol use as fuel and the standard procedure of Melle-Boinot is currently employed in sugar cane molasses fermentation. The aim of this work was to improve the overall efficiency of the batch process by recycling high levels of yeast biomass. It was observed that the volumetric productivity increased with biomass concentration, whereas the specific productivity decreased. Both variations were not linear (Fig. 1). It was difficult to keep a yeast concentration higher than 3 x 10(8) cell/ml during batch fermentation assays. Anyhow the periodic subculturing of yeast biomass (every 13 recycling periods) proved to be an effective method to obtain a high cell density in the fermentation medium (Fig. 2). The industrial application of data reported here would not imply additional investment or equipment to distilleries using standard fermentation procedures.

Ethanol↗
PubMed1977

[Fecal fermentation in meteorism].

An old test to investigate fecal fermentation was modified with the purpose of changing it from qualitative to quantitative. The modified test consists in placing in stove, at 37 degrees C for 24 hours, 5 grams of feces, suspended in water. The fermentable alimentary residues, present in the feces, suffer the action of bacteria, also there present, yielding gas that is collected and measured. Using the test, fecal fermentation was determined in 3 groups of individuals: a) 40 patients with meteorism that had persisted or improved only slightly or fairly with treatment; b) 28 apparently healthy subjects; and c) 6 patients with meteorism that had disappeared or become minimal with treatment. In the group of 28 apparently healthy subject, the obtained results varied from 0.1 to 1.1 ml gas/24 h., with a mean +/- s.d. of 0.55 +/- 0.29 ml. gas/24 h. When a distribution curve was made with the results obtained in the group of 40 patients with meteorism, these results separated into 2 subgroups: one subgroup with 28 patients, in whom results varied from 1.0 to 13.3 ml. gas/24 h., with a mean of 4.8 gas/24 h. (only) in 1 of these 28 patients a normal result of 1.0 ml. gas/24 h. was obtained, while in the remaining 27 patients results of 1.5 or more ml. gas/24 h. were obtained); and the other subgroup with 12 patients, in whom results varied from 0.0 to 0.9 ml. gas/24 h., with a mean of 0.29 ml. gas/24 h. Finally, in the group of 6 patients with successfully treated meteorism, results were from 0.1 to 0.9 ml. gas/24 h., with a mean of 0.4 ml. gas/24 h. The above mentioned results strongly suggest the existence of a relationship between meteorism and exagerated fecal fermentation. The nature of this relationship has not yet been completely clarified. However, the test used to determine fecal fermentation already promises to be very helpful for a better understanding and management of meteorism.

Adult↗
PubMed1984

[Oleandomycin content of mycelium and fermentation solution during cultivation of Streptomyces antibioticus].

The time-course of the oleandomycin content in the mycelium and fermentation broth-filtrate was studied by the microbiological assay at different periods of cultivation of strains 471 and 961 in fermenters and flasks containing a rich soybean-corn medium. It was shown that centrifugation of the mycelium over the sucrose density gradient induced a 25-80 per cent decrease in its moist weight at the expense of removal of the admixture components of the rich medium. Addition of glucose (2 per cent) to the culture-grown in a lactose medium by the 72nd hour of fermentation had no effect on further increase of the cell biomass. However, it lowered the content of the mycelium-fixed and excreted antibiotic at all the subsequent fermentation periods. The content of oleandomycin in the untreated mycelium was only 0.36 per cent of its content in the fermentation broth filtrate. After centrifugation of the mycelium over the sucrose density gradient and its intensive washing with distilled water the content of the mycelium-fixed antibiotic decreased still more. The time-course of the content of the mycelium-fixed and excreted oleandomycin was characterized by the presence of two activity peaks; by the 80-110th and by the 140-170th hour of cultivation.

Culture Media↗
PubMed1984

Experimental study of the nutritional biological characters of fermented milks.

Fermented milks (yogurt, kefir, sour milk), compared with milk for their non-protein nitrogen and free amino-nitrogen contents gave higher values prior to as well as 1, 2 and 3 h after pepsin digestion in vitro. In feeding trials of 6 weeks duration with diets based on casein, milk and fermented milks, respectively, those groups of weanling (50 to 60 g) male Wistar rats showed the maximum increments of body mass which had been fed the diets based on fermented milks. The highest values of the protein utilization index (increase in body mass in g per protein intake in g) were found in the animals kept on the fermented milk products. The favourable protein utilization and body mass increment on fermented milk diets are attributed to a better digestibility of proteins in these products.

Animals↗
PubMed1980

In vitro fermentation of feces from normal and chronically diarrheal horses.

Feces from 13 healthy horses and 8 horses with chronic diarrhea were subjected to an in vetro fermentation procedure that had been developed for rumen fluid. Fermentations were conducted over 6 hours in a closed system, with and without an essential amino acid (EAA) mixture being added to the basic starch-buffer medium. The addition of EAA caused no significant difference in results of fermentation of feces from healthy horses. For diarrheic animals, there was a significant (P less than 0.01) increase in gas and total volatile fatty acids production whether EAA were present or not, and alpha-amino nitrogen was utilized in significantly (P less than 0.01) greater amounts only if EAA was present. Fermentations were repeated on feces from five of the eight diarrheal horses after they had been treated with oral iodochlorhydroxyquin for 1 week, and had shown desirable clinical response. A significant difference was not shown between pre- and posttreatment fermentations, except for decreased butyrate production. The results are consistent with the hypothesis that chronic equine diarrhea is primarily a colonic disease and indicates that colonic maldigestion may, in part, be responsible for excess fecal water.

Amino Acids, Essential↗
PubMed1984

Effect of fermented milk diets on regeneration of the rat liver.

In a comparative study of milk versus fermented milk (yogurt, kefir, sour milk) diets concerning their effect on body mass and on liver regeneration in partially (70%) hepatectomized male CFY rats significantly higher values were found three weeks after the operation in the groups fed on fermented milk diets than in those fed on milk-based diets. No differences between the chemical components of the regenerated liver (solids, total lipids, total N) were found either between the individual groups, or between the various groups and the control. The regenerated liver corresponded to the normal organ in every respect. The values reflecting the increments of solids, total lipids and total N of the regenerating liver, whether expressed in absolute figures or in per cents, were found to be higher in the animals fed fermented milk diets than in those fed milk-based diets. The invention that the biochemical changes associated with bacterial fermentation of milk are beneficial to liver regeneration provides new evidence in support of the high biological nutritive value of fermentation.

Animals↗
PubMed1984

[Effect of the addition of sorghum and molasses on the fermentation of bovine colostrum].

In this study, ground sorghum (7.5%) and molasses (10%) were added to fresh bovine colostrum. The two mixtures and the fresh colostrum, used as control, were allowed to ferment for 21 days. Significant differences (P less than 0.05) were found by analysis of variance, comparing lactic acid production in the control fermented colostrum (0.399 g/100 ml) and molasses (0.504 g/100 ml), as well as ground sorghum fermented colostrums (0.649 g/100 ml). The lowest amino acids degradation occurred in the sorghum fermented colostrum, while the control colostrum revealed the greatest degradation. No significant differences were found by analysis of variance comparing pH, crude protein percentage, and moisture of the two treatments and of the control. It is concluded that the addition of ground sorghum to fresh bovine colostrum increases the lactic acid content post-fermentation. It also reduces the amino acids degradation, resulting in an improved product for feeding calves.

Amino Acids, Essential↗
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↗
PubMed1984

31P nuclear magnetic resonance studies of the fermentation of glucose to ethanol by Zymomonas mobilis.

High resolution 31P nuclear magnetic resonance spectroscopy has been employed to study the fermentation of glucose to ethanol by Zymomonas mobilis, strain ZM4, a bacterium which uses the Entner-Doudoroff pathway. The levels of nucleoside triphosphates, sugar phosphates, UDP-sugars and Pi in intact fermenting cells have been studied with a time resolution of 1 min. It is suggested that a pH gradient is established across the cell membrane during fermentation and that the intracellular pH does not rise above approximately 6.4. 31P resonances from most phosphorus-containing intermediates in the Entner-Doudoroff pathway, as well as adenosine and uridine nucleotides and a number of other intracellular metabolites, have been assigned in perchloric extracts of fermenting cells by means of a number of techniques, including two-dimensional homonuclear J-resolved and two-dimensional homonuclear shift-correlated spectroscopy. Quantification of these metabolites in spectra of extracts of fermenting cells indicates that the rate-limiting steps in the Entner-Doudoroff pathway in Z. mobilis are the conversions of glucose 6-phosphate to 6-phosphogluconate and of 3-phosphoglycerate to 2-phosphoglycerate.

Ethanol↗
PubMed1983

Interactions of microbial populations in cellulose fermentation.

Fermentation of cellulose in the rumen occurs through the interactions of many microbial species. The initial degradation of cellulose is caused by cellulase-producing organisms. The soluble hydrolysis products are used by both cellulolytic and noncellulolytic organisms to produce acetate, propionate, and butyrate and the important intermediates H2 and succinate. Interactions between species are necessary for the decarboxylation of succinate to propionate. H2 is used by methanogenic bacteria to reduce CO2 to CH4. The removal of H2 by methanogenesis increases the production of acetate from carbohydrates by several important cellulose- and carbohydrate-fermenting microbial species. Monensin and lasalocid appear to alter the overall fermentation by selecting for populations that produce relatively larger amounts of propionate and against populations that produce relatively larger amounts of acetate and H2. Cellulose fermentation in the human large intestine is compared with fermentation in the rumen.

Anaerobiosis↗
PubMed1995

Comparison of lactulose and inulin as reference standard for the study of resistant starch fermentation using hydrogen breath test.

Disaccharide lactulose is commonly used as a standard to quantitate the colonic fermentation of undigested sugars by means of H2 breath measurements. However, its high hydrogen production rate during fermentation may make it inappropriate for mimicking the fermentation of more complex carbohydrates, such as starch. Indigestible carbohydrates with a higher molecular weight might be more suitable than lactulose as a standard in H2 breath studies of starch digestibility. To test this hypothesis, we measured H2 breath in 8 healthy volunteers after a standard meal supplemented with 5 g or 10 g of lactulose or inulin, an indigestible oligosaccharide with an average degree of polymerization 4.5 times higher than that of lactulose. The results were then compared with those obtained after a standard meal containing a known amount (6.1 g) of resistant starch from high-amylose corn starch. Median H2 breath excretion per gram of reference carbohydrate was lower after the 5 g dose of inulin than after the 5 g dose of lactulose (19.1 vs 26.6 ppm x h x g-1; Wilcoxon's rank test p = 0.021) but similar after the two 10 g doses (inulin 22.4; lactulose 23.6; p = 0.234). Median H2 breath excretion per gram of resistant starch was significantly lower than that for both lactulose and inulin (p < 0.02), being 4.7 ppm x h x g-1. In vitro fermentation for 8 hrs with fecal homogenate showed similar mean hydrogen production rates for inulin and lactulose (30.5 vs 27.7 mL/mg fermented carbohydrate), and a significantly lower rate for starch (9.1 mL/mg) (n = 7; ANOVA p = 0.0007).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Studies on high concentration ethanol fermentation of raw ground corn by Saccharomyces sp. H0.

In this study, high concentration alcoholic fermentation coordinated with saccharification from raw ground corn was performed at 30 degrees C, pH 4-5, in batch culture using Saccharomyces sp. H0 which was constructed by hybridization in this laboratory and the glucoamylase preparation produced on a large scale in China. The optimal conditions for high concentration ethanol production were that the amount of the glucoamylase preparation was 300 u/g of raw ground corn, the inoculum size of the yeast was 2.7 x 10(6) cells/ml, the fermentation temperature was 30 degrees C, the starting concentration of raw ground corn was 33.0% (w/v), and the fermentation period was 70 hr. At the end of fermentation, 17.5% (v/v) ethanol was yielded, with 0.19% reducing sugar, 3.5% total sugar and 16.0% cell viability remaining in the fermented mash. In the case of 36.0% (w/v) of the initial raw ground corn concentration, the strain could produce 18.0% (v/v) ethanol, leaving 0.81% reducing sugar and 5.1% total sugar in the media. We found that the glucoamylase preparation which is usually employed for saccharification of cooked starch could be used for efficient saccharification of raw ground corn starch.

Edible Grain↗