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PubMed1992

[Nutritional evaluation of rice flour fermented with Rhizopus oligosporus].

In order to increase the proteic content of rice meal, fermentation with Rhizopus oligosporus was performed. During fermentation, samples were taken at the times of 0,20,30,40,50,60,70 and 80 hours. These samples were oven dried and further analysed. The amino acid composition of rice meal had lysine and threonine the most limiting ones. After fermentation the lysine content increase and the more limiting were the sulfur amino acids methionine and cystine (76.04%), threonine (91.03%) and lysine (97,04%. With the aim of verifying the biological value of the protein a bioassay was carried out. The fermented rice meal presented a higher digestibility value and the net protein utilization for the fermented rice meal lower than for the non fermented one.

Amino Acids↗
PubMed2004

[Producing human lactoferrin by high-density fermentation recombinant Pichia pastoris].

BACKGROUND: To evaluate expression of human lactoferrin gene by high-density fermentation in recombinant Pichia pastoris on the premise of maintaining its biological activities. METHODS: The neutrophil was isolated from human peripheral blood and its total RNA was prepared. Full-length cDNA of human lactoferrin gene was then obtained by RT-PCR, cloned into expression vector pPIC 3.5 K and transformed into Pichia pastoris strain KM71. With two-layer filter method, the transformants with high-productivity of human lactoferrin were screened out into fed-batch high-density fermentation. And later, the physical, chemical and biological activities of fermentation product were detected preliminarily. RESULTS: The strain p3.5-k-7 with better productivity of human lactoferrin was screened out into fed-batch high-density fermentation. The fermentation lasted nearly for nine days, with A-600 of culture once above 260 and the highest productivity of human lactoferrin being 115 mg/L, 7.67 times the amount of that in shake flask cultivation. CONCLUSION: The authors successfully realized high-density fermentation expression of human lactoferrin gene in recombinant Pichia pastoris.

Cloning, Molecular↗
PubMed2003

[Kinetic models for the effect of temperature on batch glutathione fermentation by Candida utilis].

Glutathione (L-gamma-glutamyl-L-cysteinylglycine), one of the major non-protein thiol compounds, is widely distributed in living cells and plays an important role in maintaining the normal redox environment of cells as an antioxidant. In the production of glutathione by fermentation, temperature is one of the most important environmental factors that affect the yield and the productivity of glutathione. Here the effect of temperature, varied from 24 degrees C to 32 degrees C, on the batch fermentation of glutathione in a 7 L stirred fermenter by Candida utilis WSH 02-08 was investigated. It was found that cell growth was hastened along with the increase of temperature. The maximum dry cell weight was achieved approximately 16 g/L under various temperatures, as soon as the glucose was exhausted. The effect of temperature on glutathione production was different from that on cell growth: the lower the temperature, the higher the glutathione production, i.e. the maximum glutathione concentration at 32 degrees C (235 mg/L) was only 75% and 64% of that at 30 degrees C and 26 degrees C, respectively. The maximum average specific growth rate (0.13 h(-1)) was achieved at 30 degrees C while the maximum glutathione concentration (366 mg x L(-1)) and the maximum intracellular glutathione content (2.3%) were obtained at 26 degrees C. Therefore, the optimum temperatures for cell growth and glutathione production are quite different in the batch fermentation. A modified Logistic equation was successfully applied to estimate the kinetics of cell growth. The maximum specific growth rate and the substrate inhibition constant, calculated from this equation, were both increased along with the temperature. In addition, the glutathione fermentation by C. utilis WSH 02-08 under various temperatures was proven to be a partial growth-associated process by estimating the process with the Luedeking-Piret equation. Based on the estimated parameon the estimated parameters, the effect of temperature on the kinetics of cell growth was further studied. An equation, dX / dt = [0.0224(T + 1.7)]2 X(1-X/Xmax) / 1 + S/ {8.26 x 10(6) x exp [-31477/R/(T+273)]}, was developed and applied to interlink the relationship between biomass concentration and temperature as well as substrate concentration in the batch glutathione fermentation. The experiment results showed that this model could predict the growth pattern very well.

Candida↗
PubMed2004

[Production of recombinant humanized anti-HBsAg Fab antibody by fermentation].

In order to produce recombinant human anti-HBsAg Fab antibody in Pichia pastoris, the recombinant yeast was fermented using fed-batch system in a 30 L bioreactor. The fermentation temperature was 30 degrees C, the pH was 5.0 approximately 5.3, and the DO was 20% approximately 30%. The recombinant Fab antibody was purified from crude culture supernatant by ion exchange and analyzed by SDS-PAGE and western blot and ELISA. When the absorbance (OD600) of broth reach 300 at the end of fed-batch phase, the induced phase was initiated. The results showed that recombinant human anti-HBsAg Fab antibody was high-level expressed in recombinant Pichia pastoris using a fed-batch fermentation system. Both chains of the Fab were successfully expressed upon methanol induction. After 192 h of induction, the expression level of recombinant Fab (soluble) reached 412 mg/L. The recombinant Fab antibody was purified effectively by ion-exchange chromatography from the fermentation supernatant to a purity of 95%. And the affinity activities of the purified recombinant Fab antibdy and fermentation supernatant were detected, and both of them showed high affinity activities. The results demonstrated that recombinant human anti-HBsAg Fab antibody could be high level produced by fed-batch fermentations in Pichia pastoris. Which can be efficiently used in industrial production.

Fermentation↗
PubMed2005

Fundamentals of the fermentative production of hydrogen.

The molecular details behind hydrogen evolution during fermentation are reviewed. Hydrogen is evolved by hydrogenase, a class of enzymes containing complex metallo-centers. In most cases, sugars are degraded to pyruvate which in turn is converted to a variety of fermentation products. Various pathways leading to fermentative hydrogen generation are outlined and discussed. Thermophilic fermentations have higher yields than mesophilic ones. Yields are thought to be limited to 4H2 per glucose under standard conditions. The highlights of some actual studies of fermentations are presented and ways of potentially increasing hydrogen yields are discussed. It may be possible to achieve higher hydrogen yields by carrying out fermentations under microaerobic conditions where limited respiration could provide additional reducing power to drive the nearly complete conversion of sugar substrates to hydrogen.

Bacteria, Anaerobic↗
PubMed1992

[Effect of monensin (USA, Czechoslovakia, Bulgaria) on fermentation of animal feed in an artificial rumen (Rusitec)].

An experiment was made with the Rumen Simulation Technique (Rusitec) in which the fermentation of a mixed ration of hay (12.8 g/d) and bruised barley (3.2 g/d) was compared with the fermentation of the same diet in the presence of 5 mg monensin/d from the USA, CSFR and Bulgaria. The fermentation of the mixed ration was significantly affected by all three kinds of monensin. The digestibility of dry matter (DM) in the rations declined in the presence of monensin from 48% to 40% (tab. I). The digestibility of detergent fibre, cellulose and hemicellulose also declined in the presence of monensin (tab. I). The production of methane decreased (-70%) and CO2 production dropped too, but this decrease could be accounted for by the changes in the production of volatile fatty acids and redistribution of metabolic hydrogen (tab. I). Monensin decreased the production of total volatile fatty acids (-21%), the production of acetic (-35%), n-butyric, n-valeric and isovaleric acids (tab. II) and increased the production of propionic acid (+60%). The production, utilization and recovery of metabolic hydrogen were significantly increased in the presence of all three kinds of monensin (tab. IV). The end products of fermentation were affected by an addition of monensin to the mixed ration. All three kinds of monensin increased energic efficiency of volatile fatty acids, decreased adenosinetriphosphate (ATP) production, the amounts of fermented hexose, organic matter fermented and utilization of glucose (tab. III).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed2006

A unique feature of hydrogen recovery in endogenous starch-to-alcohol fermentation of the marine microalga, Chlamydomonas perigranulata.

A unicellular marine green alga, Chlamydomonas perigranulata, was demonstrated to synthesize starch through photosynthesis, store it in a cell, and ferment it under anaerobic conditions in the dark to produce ethanol, 2,3-butanediol (butanediol), acetic acid, and carbon dioxide (CO2). Previous fermentation data of an algal biomass cultivated outdoors in a 50-L tubular photo-bioreactor showed good carbon (C) recovery in the fermentation balance, with a higher ratio to alcohols and, therefore, lower ratio to CO2 in the C distribution of products than what would be expected from the Embden-Myerhof-Parnas pathway. These findings led to a proposed concept for a CO2-ethanol conversion system (CDECS). The above data were evaluated in terms of hydrogen (H) recovery with the following results: C recovery at 105% was well balanced, although H recovery was as high as 139%, meaning an additional gain of H through fermentation. This finding was reproduced wholly in a set of experiments carried out in the same month of the following year, October, whereas another set of experiments was carried out in the following June provided ordinary fermentation results in terms of C and H recoveries with poor growth. Further analyses of these data revealed that butanediol is equal to ethanol as a product from a putative conversion system from CO2 to the detected fermentation products, leading to the revision of the CDECS concept to a CO2-alcohol conversion system (CDACS). The relevance of the CDACS will be discussed in relation to the cultivation conditions employed by chance.

Animals↗
PubMed1989

Maloalcoholic fermentation by immobilized Schizosaccharomyces pombe.

Cells of Schizosaccharomyces pombe TMB 1138, which are capable of metabolizing-malate, was immobilized in calcium alginate gel to carry out maloalcoholic fermentation. Four milliliters of cell suspension containing about 2.0 X 10(7) cells were entrapped in 16 ml of sodium alginate solution in order to prepare 2% Na-alginate (w/v) gel bead. After activation by incubating at 28 degrees C for 24 h in grape juice, 300 beads of immobilized cells were inoculated into the fermentation medium. After fermentation was proceeded at 25 or 28 degrees C for 24 h by shaking, it could metabolize L-malate completely and the total acidity was also reduced. Under the same condition for batch fermentation, it was found that the utilization of L-malic acid was over 97% for the first 7 days in fermentation medium, 85% for the first 4 days in grape juice and 87% for the first 4 days in wine. Furthermore, for the continuous fermentation in wine, the conversion of L-malic acid reached 92% in 24 h and could be maintained at 75% in the following 9 days.

Alginates↗
PubMedDate not supplied

[Effect of carbon composition of the fermented medium on the synthesis of volatile acids by the yeast Saccharomyces carlsbergensis 776].

The effect of glucose, maltose and sucrose on the synthesis of volatile oils during fermentation of model carbohydrate solutions (6, 8 and 11%) by the yeast Saccharomyces carlsbergensis 776 was studied. The composition and concentration of carbohydrates affected the build-up of volatile fatty acids during fermentation. The accumulation of biomass and volatile fraction of fatty acids reached maximum on the medium containing 11% glucose. There was a certain correlation between the biomass synthesis and accumulation of volatile fatty acids, i.e. with an increase in the biomass the content of volatile fatty acids in the medium increased. During fermentation of disaccharide solutions cell multiplication diminished and the fermentation process accelerated. Ethanol, residual sugar and acidity of fermented solutions increased with the initial concentration of carbohydrates. The pH value of the fermented must remained essentially unaltered independent of the sugar amount used.

Culture Media↗
PubMed1982

Biochemical differentiation of Haemophilus influenzae. Additional characterization of biotypes by carbohydrate fermentation patterns.

A total of 295 strains of H. influenzae was characterized by serotyping and biochemotyping following the scheme of Kilian. Biotype II was the biotype most frequently seen (41.4% of the strains). The strong correlation of serotype b with biotype I was confirmed. Carbohydrate degradation was evaluated as a possible aid for further characterization of biotypes. Differing results were obtained concerning the fermentation of fructose, maltose and xylose which were classified into five carbohydrate fermentation patterns A-E. To a certain degree the carbohydrate fermentation patterns of the strains could be associated with biotypes. No conclusion could be drawn, however, from carbohydrate fermentation patterns regarding sites of isolation and probable virulence of H. influenzae strains. The results of serotyping, biochemotyping according to Kilian and carbohydrate fermentation pattern analysis were correlated with clinical syndromes associated with isolation of the strains. Carbohydrate fermentation patterns permit a further differentiation of the serotype b/biotype I strains which can cause meningitis and other severe H. influenzae infections. A far more heterogeneous distribution of biochemical characteristics in strains isolated from the respiratory tract might facilitate epidemiological studies on respiratory diseases due to H. influenzae.

Bronchitis↗
PubMedDate not supplied

[Arabinose, melibiose and xylose oxidation and fermentation in "Serratia" (author's transl)].

The oxidative and fermentative metabolisms of D(+)raffinose, D(-)arabinose, L(+)arabinose, D(+)melibiose and D(+)xylose were compared in 181 strains belonging to the genus Serratia, including collection strains and clinical isolates from various sources. At 30 degrees C, raffinose was neither fermented nor oxidized by S. marcescens, but was fermented by S. liquefaciens and S. rubidaea. D(-)arabinose was oxidized by all strains. L(+)arabinose, melibiose and xylose were fermented by all S. liquefaciens and S. rubidaea, while they were oxidized by most S. marcescens. Two strains of the latter species, however, were able to ferment xylose. The use of Hugh and Leifson's oxidation-fermentation medium containing melibiose or L(+)arabinose can help to differentiate S. rubidaea from pigmented strains of S. marcescens and to differentiate S. liquefaciens from unpigmented strains of S. marcescens.

Arabinose↗
PubMed1994

[The effect of cadmium on the protozoan population and rumen fermentation of feed in an artificial rumen].

In our experiment, the effects of 5, 10 and 20 mg cadmium per kg dry matter (DM) on protozoan population and rumen fermentation of feed ration consisting of 11.7 g DM of hay and 2.8 g DM of barley (80: 20%) were followed in artificial rumen (Rusitec). The results of the experiment showed that the addition of 5 and 10 mg cadmium per kg DM less significantly (P < 0.05) decreased the digestibility of DM, organic matter and neutral detergent fibre and significantly (P < 0.01) decreased the digestibility of cellulose of feed ration. It is interesting that the addition of 20 mg cadmium per kg DM did not influence these parameters. Although the total gas production showed a tendency of decrease due to the influence of the addition of 5, 10 and 20 mg cadmium/kg DM, methane and CO2 production was not altered. However, cadmium significantly influenced the production of individual volatile fatty acids-VFA's (mmol/day). The addition of 5, 10 and 20 mg cadmium per kg DM significantly increased acetic acid production (by 10-20%) and decreased propionic acid production (by 18-30%). Therefore, the acetate: propionate ratio was significantly increased (from 1.57 to 2.45-2.60) by the addition of cadmium. The production of n-valeric and iso-valeric acids was also significantly decreased in comparison with the control. The decrease of individual VFA's was more significant at the higher amount of cadmium added into the fermentation system. The proportions of individual VFA's in total VFA production expressed in molar % showed a similar character. The changes in the production of individual VFA's due to the influence of the addition of 5, 10 and 20 mg cadmium per kg DM caused a decrease in energetic efficiency of VFA's (P < 0.001) in comparison with the control. The other parameters of rumen fermentation - utilization of glucose, adenosine triphosphate (ATP) production, fermented hexose, fermented amino acids and fermented organic matter (OMF) were not influenced by the cadmium addition. Although the total microbial matter production in effluent and undigested feed (residues) was significantly (P < 0.001) decreased by the addition of 5, 10 and 20 mg cadmium per kg DM, the efficiency of microbial synthesis expressed as YATP and g microbial N/kg OMF was not changed and achieved the values 11.78-12.68 (YATP), 25.56-28.35 (g microbial N/kg OMF), respectively. The total protozoan population was significantly decreased by the cadmium addition mainly as a result of the decrease of infusoria of Entodinium spp.(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Feed↗
PubMed1994

Fermented dairy products, calcium, and colorectal cancer in The Netherlands Cohort Study.

Experimental studies suggest that an increased consumption of fermented dairy products and calcium might decrease the risk of colorectal cancer. The associations between fermented dairy products, dietary calcium, and colorectal cancer risk were investigated in a population with a wide variation in intake of dairy products. The Netherlands Cohort Study of diet and cancer started in 1986 when 120,852 Dutch men and women, ages 55-69, filled out a questionnaire concerning dietary patterns and lifestyle. The present analysis is based on 3.3 years of follow-up and includes 215 incident cases of colon cancer and 111 incident cases of rectal cancer, excluding cases diagnosed in the first year of follow-up. After adjustment for potential confounding variables, colorectal cancer risk was weakly inversely associated with the consumption of fermented milk [relative rate (RR) in the highest category of intake compared to nonusers, 0.89; 95% confidence interval (CI), 0.60, 1.33], unfermented milk (RR, 0.86; 95% CI, 0.57, 1.29), and cheese (RR, 0.88; 95% CI, 0.59, 1.33). However, category-specific relative rates and tests for trends were not statistically significant. For fermented milk, the inverse association was limited to colon cancer (RR, 0.70; 95% CI, 0.43, 1.15; trend, P = 0.33). In crude and multivariate models, total dietary calcium intake (highest versus lowest quintile, RR, 0.92; 95% CI, 0.64, 1.34) and calcium from fermented dairy products (RR, 1.14; 95% CI, 0.77, 1.68) were not significantly associated with colorectal cancer risk. Calcium from unfermented dairy products was inversely associated with rectal cancer risk (RR, 0.55; 95% CI, 0.30, 1.04; trend, P = 0.03). After 3.3 years of follow-up, these data are not consistent with a substantially decreased risk of colorectal cancer with increased intake of fermented dairy products and dietary calcium.

Aged↗
PubMed1996

Screening for L-arabinose fermenting yeasts.

Utilization of pentose sugars (D-xylose and L-arabinose) derived from hemicellulose is essential for the economic conversion of biomass to ethanol. Xylose-fermenting yeasts were discovered in the 1980s, but to date, no yeasts have been found that ferment L-arabinose to ethanol in significant quantities. We have screened 116 different yeasts for the ability to ferment L-arabinose and have found the following species able to ferment the sugar: Candida auringiensis, Candida succiphila, Ambrosiozyma monospora, and Candida sp. (YB-2248). Though these yeasts produced ethanol concentrations of 4.1 g/L or less, they are potential candidates for mutational enhancement of L-arabinose fermentation. These yeasts were also found to ferment D-xylose.

Aerobiosis↗
PubMedDate not supplied

[Survival of Listeria monocytogenes in milk fermented with a starter culture for making yogurt].

The purpose of this research was to determine the survival of Listeria monocytogenes in sterile skim milk during the fermentation with a yogurt starter culture and during storage at refrigeration temperature. Sterile skim milk was inoculated with 10(3), 10(5) and 10(7) cfu/ml of L. monocytogenes and with 10(6) cfu of lactic acid bacteria. Inoculated milks were fermented for 8 h at 42 degrees C, followed by refrigeration at 4 degrees C. Samples were taken at 2 h intervals during fermentation and at 2 days intervals during storage. Acidity and pH were measured, as well as viable count of lactic acid bacteria and pathogen. L. monocytogenes survived 8h, 10 days and 32 days in the fermented milk, when the inocula were 10(3), 10(5) and 10(7) cfu/ml, respectively. Inhibition of the pathogen was associated with a decrease of pH below 4.0 and increase in acidity. It was demonstrated that this pathogen is able to survive several weeks in milk fermented with a starter culture, contrary to the general belief which considered it very difficult due to the low pH. Therefore fermented milks may play an important role in the transmission of these bacteria.

Animals↗
PubMed1994

[Chemical changes in colostrum fermented with sorghum].

Colostrum from Holstein cows was collected during the first three days post partum. Ground sorghum (7.5%) was added to it. Untreated colostrum used as control, and sorghum treated colostrum samples were allowed to ferment for 0, 8 or 21 days at 18-20 degrees C in glass containers; pH, moisture, crude protein, digestible protein, ammonia, lactic acid and total energy were analyzed in untreated and treated samples. Crude protein was not significantly different (P > 0.01) in control colostrum (7.12, 5.76, 5.70%) and treated colostrum (6.66, 5.71, 5.98%) at 0, 8 and 21 days of fermentation respectively. Digestible protein was higher (P < 0.01) in the untreated (90.0, 93.0%) than in the treated colostrum (89.0, 81.0, 86.0%). Ammonia content was also higher (P < 0.01) in the control (0.25, 1.31, 1.37%) than in the treated one (0.23, 0.97, 1.20%). Lactic acid was lower (P < 0.01) in the untreated colostrum (0.82 g/100 ml) than in the treated colostrum (1.24 g/100 ml) after 21 days of fermentation. Total energy values were lower (P < 0.01) at 8 and 21 days of fermentation in the untreated (0.91, 0.84 Kcal/g) than in the treated colostrum (1.16, 0.97 Kcal/g). The addition of sorghum to colostrum reduced the crude, protein degradation and the ammonia content after 8 and 21 days of fermentation, increasing total energy and lactic acid content after 21 days of fermentation.

Ammonia↗
PubMed1998

Fermentation of non-starch polysaccharides in mixed diets and single fibre sources: comparative studies in human subjects and in vitro.

The present study investigated whether the extent of fermentation of NSP in human subjects could be predicted by an in vitro batch system. Fibre sources studied were five mixed diets containing different amounts and types of fibre and three single fibre sources (citrus fibre concentrate, coarse and fine wholemeal rye bread). Fermentation in human subjects was determined in balance experiments in women who were also donors of the faecal inocula. In vitro fermentations were performed with fibre residues prepared from duplicates of the fibre-containing foods consumed during the balance trials. Fermentation of total NSP in vivo was between 65.8 and 88.6% for the mixed diets and 54.4, 58.0 and 96.9% for the coarse and fine wholemeal rye breads and the citrus fibre concentrate respectively. For the mixed diets and the citrus fibre concentrate, mean differences between the extent of NSP degradation after 24 h in vitro incubation and that in vivo were between -0.7 and 5.0%. Differences were significant for one diet (P < 0.05). For the wholemeal rye breads, the fermentation in vitro exceeded that in vivo significantly, but the magnitude of the difference in each case was small and without physiological importance. Particle size of breads had no influence on the extent of NSP degradation. These results indicate that the in vitro batch system used could provide quantitative data on the fermentation in vivo of NSP in mixed diets and some single fibre sources. An in vitro incubation time of 24 h was sufficient to mimic the NSP degradation in vivo.

Adult↗
PubMed1976

[Taxonomic importance of fermentation balances of Enterobacteriaceae (author's transl)].

Fermentation balances have been studied on 66 strains from 9 taxa of Enterobacteriaceae. In addition, 6 strains of Aeromonas have been investigated. Among these fermentation balances, 7 types could be distinguished. It was shown, that the taxa of Enterobacteriaceae differed with respect to the balance types involved. This is true especially for VP-positive taxa. For example, Hafnia, the Klebsiella-Enterobacter-Serratia group, Enterobacter cloacae and Erwinia are to some extend characterized by different balance types. The groups of Enterobacteriaceae with plain acid fermentation are apperently more homogenous with respect to fermentation balances. Balances are, however, not suited for classification, because no balance type turned out to be absolutely group specific. The fermentation balances of our strains of Aeromonas are closely related to the acid-type balances of Enterobacteriaceae. A numerical classification of the data showed, that this method is most potent in sorting multivariate data. A basic agreement of both techniques, the subjective and the numerical subdivision, was found. The first one, however, tends to overemphasize differences among the types. A comparison between the quantitative data of fermentation balances and the corresponding diagnostic tests (MR, VP, Gas) gives information on the reliabiity of the latter.

Acetoin↗