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PubMed2006

[The dynamics of microorganism populations and fermentation characters of co-cultures of rumen fungi and cellulolytic bacteria on different substrates].

In vitro co-culture technique and DGGE were used to investigate the dynamics of microorganism populations and fermentation characters of co-cultures of rumen fungi and cellulolytic bacteria at different substrates (concentrate to crude ratio in treatment A to E was all rice straw, 3:7, 5:5, 7:3 and all corn, respectively). The results showed that, compared with Oh, fungal population density at 24h increased in treatment B and C, but decreased in treatment A and D, and no fungi was detected in treatment E; but cellulolytic bacteria population at 24h increased with the increasing of concentrate to crude ratio. At the end of 48h fermentation, no fungi were detected in all treatments; cellulolytic bacteria population increased from treatment A to treatment C, but decreased from treatment D. DGGE results showed that samples collected in treatment A, B and C had similar DGGE patterns with about 11 dominant bands, but dominant bands in treatment D and E decreased markedly compared to treatments A, B and C. With the increasing of concentrate to crude ratio, pH value of the co-culture decreased dramatically (P < 0.05). During the fermentation periods, acetate was the major VFA in co-culture, the acetate to propionate ratio decreased from treatment A to treatment C, but increased from treatment D. With the increasing of concentrate to crude ratio, the total VFA at 48h increased from treatment A to treatment C, and then decreased. At the end of 48h fermentation, CMCase activity and xylanase activity were highest in treatment A. alpha-Amylase activity increased from treatment A to treatment D, but treatment E was the lowest in all treatments.

Animals↗
PubMedDate not supplied

[Methods for the study of microbial communities in fermented foods].

The importance of ecological concepts to understand the presence and growth of microorganisms in foods is presently recognized. The production of fermented foods under controlled conditions and its safety assurance depend on the knowledge and control of their microbiota. Traditional fermented foods are obtained by natural fermentations (in which no inoculum is added) and contain complex microbiotas, which are difficult to describe through the use of traditional microbiological methods. The microbial structure of these foods can be studied with different approaches. One of them consists on the typification of isolated microorganisms with methods based on DNA as RFLP, ribotyping, AFLP, ARDRA and RAPD. In order to detect non-culturable or not yet cultured microorganisms, nucleic acids are directly extracted from foods and the microbial diversity is determined from them. Examples of these techniques are the construction of 16S rDNA clone libraries and fingerprinting techniques, such as DGGE and TGGE. Recent advances on the application of these techniques on the study of fermented foods are presented.

Bacteria↗
PubMed1991

[The course of rumen fermentation during alkalosis in cows].

The aim of the study was the investigation of rumen fermentation during alkalosis in cows. The study comprised some parameters of rumen fermentation, such as: pH, ammonia and volatile fatty acids (VFA) levels, also relationship between VFA, numbers of population of protozoa and bacteria, total production of gases in vitro particularly CO2 and CH4, amounts of lactic and total protein in rumen fluid and non-glucogenic/glucogenic ratio (NGGR) in the VFA mixture. On the basis of obtained results the amounts of fermented hexose, cell yield, ATP produced and hydrogen utilization were calculated. During alkalosis there was observed significant fall of VFA production, especially acetic and butyric acids, also lower production of gases, particularly CH4--probably as a result of selective reduction of methanogenic strain bacteria. The levelling of value of rumen pattern of fermentation occurred after the beginning of lactation probably as a result of metabolism products excretion together with milk.

Acetates↗
PubMed1991

[Alcoholic fermentation in "Schwabischen Most": ethanol and alcoholic congener alcohols].

The concentrations of ethanol and congener alcohols in "Schwäbischer Most" were determined (1) at various stages throughout the fermentation process in two different types of "Most", and (2) after completed fermentation in eleven different types. The fermentation process was finished after about five weeks with a final ethanol concentration of 35-54 g/l. According to the congener alcohols the different specimens of "Most" could be classified as beverages like wine. However, the concentrations were found to vary so widely that the analysis of the beverage in question is to be recommended whenever an expert opinion is given. Our studies suggest that the alcohol concentrations do not change significantly, when the fermentation process has been finished.

Ethanol↗
PubMed1990

Technology of the divalent engineered diarrhea vaccine (K88, K99) production by high cell density fermentation and the antigen overexpression.

This paper describes the production of divalent K88, K99 antigens by high cell density fermentation and gene overexpression. The cell density reached above 40 at A600nm and the antigens were at 2(12) level. The thousands dosage of the vaccine can be made by using 10 I broth of the fermentation. The stability of the plasmid showed that about 30 percent of the bacteria lost its plasmid after 20 h fermentation. It was found that the antigens were overexpressed and located in both the pili of E. coli and in the medium in equal quantities. It means that the expression and regulation of the genes of K88, K99 may be different from the wild type of enterotoxingenic E. coli. A large number of the vaccinated pregnant sow showed that the piglets were effectively protected from the infection of enterotoxingenic E. coli. The results indicated that the large quantities requirement of the vaccine could be provided by using a small fermenter. This vaccine consists of two forms of the antigen K88, K99 which, when present in the pili as well as the medium, is more favorable to stimulate the production of antibody in the colostrum of pregnant sow.

Animals↗
PubMed1990

The characteristics of Aureobasidium pullulans fermentation process.

The fermentation kinetics, rheological property and oxygen mass transfer coefficient were studied for the fermentation process of Aureobasidium pullulans. A mathematical kinetic model based on the logistic equation and Luedeking-Piret model has been established with the experimental results. The rheology of the fermentation broth behaves as pseudoplastic non-Newtonian fluid. The oxygen mass transfer coefficient decreases during the fermentation process, an exponential equation has been postulated to describe the inter-relationship among the oxygen mass transfer coefficient, the agitation speed and the apparent viscosity of the broth.

Fermentation↗
PubMed1989

The role of cell immobilization in fermentation technology.

The distinction between immobilized cell fermentation and immobilized cell biocatalysis is seldom made, though they are conceptually quite different. Unlike immobilized enzyme systems, immobilized viable cells can be used to carry out conventional fermentations. Microbial cells which would otherwise be freely dispersed (in almost colloidal suspension) within the fermentation environment can be encouraged to become attached in some way to a support (carrier), thus producing a discrete particulate solid phase. Such immobilization offers several potential advantages of a process engineering nature to the fermentation system. These include ease of handling and of cell separation, and lowering of bulk viscosity, as well as the obvious potential benefits of increased cell concentration.

Biotechnology↗
PubMed1989

Effects of culture medium composition and temperature on hepatitis B surface antigen expression by recombinant yeast in fermentation processes.

Hepatitis B surface antigen (HBsAg, an exogenous protein) was produced by fermenting recombinant Saccharomyces cerevisiae containing the HBsAg gene. The relative HBsAg concentrations increased from 3.89 to 8.12 when glucose content was reduced and the culture medium was supplemented with glycerol and sucrose; specific activity also increased by a factor of 2.69. The temperature variation sequence for fermentation processes was established from experimental results. The amount of HBsAg gene expressed reached 13.51 in relative concentration terms. The stability of the recombinant plasmid containing the HBsAg gene was studied by the varying fermentation temperatures in a fed-batch process. There was a conversion activity distribution for the yeast containing the exogenous DNA, which affected HBsAg production by the genetically engineered yeast in fermentation processes.

Cloning, Molecular↗
PubMed1989

[Rusitec--fermentation equipment for the study of digestive processes in ruminants].

The fermentation equipment RUSITEC (Rumen Simulation Technique) is a simplified model of the rumen which stimulates the conditions inside the rumen, enables to keep the normal microbial population of the rumen for a long time under strictly controllable conditions, and enables a permanent monitoring of fermentation processes. Trials were conducted to see whether this model of "artificial rumen" can be used to determine the nutritive value of untreated beech sawdust and beech sawdust treated hydrobarothermically at the pressure of 1.4 MPa and impregnated with 1% H2SO4. The digestibility of the dry matter and fibre components was higher in the treated beech sawdust than in the untreated sawdust. In both reaction vessels, the amounts of acetic, propionic and butyric acids as well as the total VFA, were higher during the fermentation of treated beech sawdust, as compared with the diet with raw beech sawdust. The increased output of VFA, especially the acetic and butyric acids, resulted in a proportional increase in the output of gases, especially carbon dioxide and methane, as compared with the production of gases in rumens digesting untreated beech sawdust. In comparison with other in-vitro methods, this model of fermentation equipment characterizes the nutritive values of various kinds of feed in a more thorough way: using this equipment, the simulation technique has proceeded much closer to reality.

Animals↗
PubMed1989

[A study on the effect of fermented soybean in preventing iron deficiency anemia in children].

Using the fermenting technique that hydrolysis the phytate in soybeans. The absorption rate of iron was improved and a series of fermented soya foods were produced. Feeding the fermented food to 437 children for 6 months, the incidence of IDA children significantly decreased from 21.7% to 1.25%. The iron absorption rate (21.8%) in the children given the diet containing fermented soy was significantly higher than that of (14.2%) in the children given the bland diet (control group) and about the same as that in the FeSO4 group (22.48%) 58Fe.

Anemia, Hypochromic↗
PubMed1988

Systemic augmentation of the immune response in mice by feeding fermented milks with Lactobacillus casei and Lactobacillus acidophilus.

This study investigates the effect of feeding fermented milks with Lactobacillus casei, Lactobacillus acidophilus and a mixture of both micro-organisms on the specific and non-specific host defence mechanisms in Swiss mice. Animals fed with fermented milk for 8 days (100 micrograms/day) showed an increase in both phagocytic and lymphocytic activity. This activation of the immune system began on the 3rd day, reached a maximum on the 5th, and decreased slightly on the 8th day of feeding. In the 8-day treated mice, boosted with a single dose (100 micrograms) on the 11th day, the immune response increased further. The feeding with fermented milk produced neither hepatomegaly nor splenomegaly. These results suggest that L. casei and L. acidophilus, associated with intestinal mucosae, can influence the level of activation of the immune system. The possible clinical application of fermented milks as immunopotentiators is also discussed.

Animals↗
PubMed1987

Invasive infrared sensor for the determination of the cell number in a continuous fermentation of hybridomas.

A new and simple device for the on-line determination of the total cell count in fermentation vessels is presented. It is based on fibre optic techniques, produces a constant infrared signal and determines the cell count via the scattered light. The linear range between the cell count and the infrared response lies between 1 X 10(5) and more than 2 X 10(6) cells per ml. This sensor shows good correlation between the cell count and the infrared response in fermentations with cell viability of more than 80%. The feeding pumps in these fermentations can be controlled via this sensor to get fermentation with stationary cell counts.

Animals↗
PubMed1986

Protein enrichment of sugar beet residue with the inoculation of conidia of Trichoderma album by solid state fermentation.

Cellulosic material was inoculated with Trichoderma album by solid state fermentation and the change of protein, total nitrogen, mineral nitrogen, cellulose and total fiber contents of raw material were measured. It was found that the water holding capacity and bulk density of substrate increased as the fermentation progressed. The optimum C/N ratio for the conidia production was between 4 and 7, and the optimum pH was around 5. The protein enrichment of sugar beet residue were the best at the initial moisture content 76%, initial pH 4.5 and supplement with 1% nitrogen. After 4 days fermentation, the final product contained 22% of protein. From the present state of technological development, the protein enrichment of cellulosic materials by solid state fermentation proved to be valuable.

Fermentation↗
PubMed1985

[In vitro effect of 2 pharmaceutical preparations containing bismuth on the fermentative capacity of intestinal bacteria].

An investigation was done on the action in vitro of two pharmaceutical preparations containing Bi, De Nol and Pepto Bismol, on the fermentative capacity of intestinal bacteria. For the purpose, using an instrument and a technique previously described, fecal fermentation (FF) was measured in 21 stool samples, to which lactose was added to assure appreciable levels of fermentation. In 11 of the samples, FF was measured without and with addition of De Nol; and in the 10 remaining samples, without and with addition of Pepto Bismol. In 7 of the samples with which the action of De Nol was studied, this preparation significantly reduced FF from 10.9 not equal to 4.3 (mean not equal to s. d.) to 4.9 not equal to 5.0 ml of gas/24 h (p less than 0.02); on the contrary, in the 4 remaining samples, it increased FF, although not significantly, from 8.7 not equal to 4.8 to 16.7 not equal to 8.8 ml of gas/24 h (N.S.). Pepto Bismol significantly reduced FF, in all the 10 samples with which the action of that pharmaceutical - preparation was investigated, from 11.7 not equal to 6.1 to 3.0 not equal to 2.1 ml of gas/24 L (p less than 0.0001). A discussion was done on the possible mechanisms of the antifermentative action of Bi, as well as on the probable usefulness of De Nol and Pepto Bismol for the control of exaggerated intestinal fermentation and the flatulence it frequently causes.

Antacids↗
PubMedDate not supplied

[The various functions of steroids on the yeast metabolism in grape must during fermentation: the notion of survival factor (author's transl)].

The physiological effects of steroids supplied to the yeasts in grape must is complicated. These substances may function as inhibitors, as growth factors or survival factors. The steroids have a "survival factor" action when they act on aerobically cultivated yeasts, fermenting under anaerobic conditions, in grape must of high sugar concentration. In this case, the substances have no effect on the cellular multiplication but they maintain viability and fermentation activity in the resting cells. Consequently, a greater quantity of sugar is consumed and the content of secondary products is modified by the end of the fermentation. Certain growth conditions during fermentation affect the survival factor action of steroids: high temperature, low pH, vitamin deficiency, low amount of inoculum, insufficient aeration, excessive sugar concentration.

Aerobiosis↗
PubMedDate not supplied

[Effect of prolonged, continuous fermentation on the morphology and physiology of fixed yeasts].

As a result of long continuous fermentation of brewing wort by fixed yeast cells, the number of cells in the fermenter increased as well as their wet weight. The average dimensions of cells (length, width, volume) also increased. The length-to-width ratio of cells decreased. The fermenting activity decreased if calculated per wet weight but remained at the same level if calculated per cell. The overall productiveness of the fermenter with a carrier increased in proportion to the number of cells but not to their weight. The morphological and physiological properties of yeast cells changed as compared to the original ones.

Beer↗
PubMed1981

Introduction and reisolation of selected gram-positive bacteria from fermented edible wastes.

A fermentation process using Lactobacillus acidophilus added to edible food wastes was evaluated for its bactericidal action on selected gram-positive organisms. The Lactobacillus fermentation converts food wastes into an animal feed ingredient. In this study, 5 gram-positive bacteria of zoonotic importance were individually tested. These organisms were: Group E Streptococcus, Erysipelothrix rhusiopathiae, Clostridium perfringens, Corynebacterium pseudotuberculosis, and Listeria monocytogenes. For each experiment, Lactobacillus was first mixed into ground waste; one of the test organisms was then inoculated and mixed. This mixture was divided among eight 5.5-L containers and incubated (duplicates) at 5 C, 10 C, 20 C, and 30 C for 96 hours. Internal waste temperature, reduction-oxidation, and pH were monitored. Waste samples were taken initially and at subsequent 24-hour periods. Qualitative and quantitative recoveries of the test bacteria were attempted for each sample. Group E Streptococcus was reisolated in increasing numbers at all temperatures throughout the fermentation period. Erysipelothrix rhusiopathiae was recovered throughout the 96-hour period at 5 C; at 10 C it was recovered at 24 hours but not at 48 hours. Erysipelothrix rhusiopathiae was killed by 24 hours at 20 C and 30 C fermentation temperatures. Clostridium perfringens survived the entire test period at 5 C, 10 C, and 20 C; it was killed by 72 hours at 30 C. Neither Corynebacterium pseudotuberculosis nor Listeria monocytogenes was reisolated at any temperature at any time.

Animal Feed↗
PubMed1983

[Acetobutylic fermentation: strains and regional raw materials].

The purpose of the present work was to show, as a first stage, that it is possible to characterize autochtohnous strains of Clostridium acetobutilicum of a good solvent producing capacity, specially N-butanol, through the utilization of suitable techniques for isolating anaerobic microorganisms. Cassava roots were employed as raw material using suitable culture media and an anaerobic jar of cold catalyst. The fermentative capacity of the strains thus isolated was evaluated against a control strain of Clostridium acetobutilicum. Even though some of the strains showed a greater solvent producing power, most of them showed lower fermentation capacity than the control strain, which could be increased, by applying successive thermic treatments. As a second stage, and due to the low cost production of cassava in the Province of Misiones, we studied its utilization as an acetone-butanol fermentation substrate. Mashes composed of binary mixtures of cassava flour and variable amounts of integral flour maize or soy were treated with selected "starters" of Clostridium acetobutilicum, being further processed according to standardized techniques in order to obtain the already mentioned solvents. Mashes concentration influence was also studied using culture media the composition of which proved to be excellent in all experiments carried out under "static system" conditions. The highest fermentative yields (maximum value recorded: 26,20 g of total solvents, with respect to dry solids), were recorded for mashes obtained from mixtures containing integral maize flour; these showed a higher degree of nutrients utilization than those prepared with integral soy flour.

1-Butanol↗