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Identification of selected probiotic bacteria in food additives
Bubeníková, Lucia ; Španová, Alena (referee) ; Rittich, Bohuslav (advisor)
Bifidobacteria and lactobacilli are gram-positive bacteria which belong to the lactic acid bacteria group. They are ordinary constituents of gastrointestinal microflora, play a pivotal role in human nutrition and health, prevent pathogen colonization and maintain normal mucosal immunity. In present days they are used in production of functional food products and pharmaceutical additives. Polymerase chain reaction (PCR) is used to the detection and identification of bacteria which belong to the genus of Bifidobacterium and Lactobacillus. Specific primers for each genus are used in PCR reactions for in vitro amplification of definite part of DNA. In this work, total DNA was isolated from three additives (Pangamin Bifi plus, Biopron Junior and Probiodom) by the method of phenol extraction and amplified using genus-specific PCR primers giving amplicons of 523 bp (Bifidobacterium) and 250 bp (Lactobacillus). Occurrence of bacteria of both genera was proved in all of the three tested probiotic products.
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Molecular identification of selected species of lactic acid bacteria and bifidobacteria in food additives
Riegelová, Kristýna ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
Probiotic lactic acid bacteria and bifidobacteria are natural part of microflora of gastrointestinal tract. In the present, day they are grossly exploited in food processing industry. The aim of the work was molecular identification of bacteria of genus Lactobacillus and Bifidobacterium in complex matrices of two food additives. Total DNA was isolated from crude cell lysates by magnetic particles P(HEMA-co-GMA). Isolated DNA was amplified in genus-specific and species-specific PCRs. Amplicons were detected by agarose gel electrophoresis. Results were compared with declared specification given by producers in three different batches.
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Probiotické mikroorganismy ve fermentovaných mléčných výrobcích
Andrýsková, Martina
Probiotics are living microorganisms with positive impact on consumer health if consumed in adequate amounts. The disadvantage of probiotic microorganisms is its considerable instability. Due to increasing demand for probiotic foods created pressure on the quality of these products. This thesis called Probiotic microorganisms in fermented milk products, examines how the quality is affected by customer behaviour. The effect of temperature (4 °C and 10 °C) and storage time for the number of lactic acid bacteria and bifidobacteria in fermented milk products (yoghurt and kefir milk) was examined by cultivation methods. The number of beneficial bacteria in baby food was also specified. Based on the results of this experiment it can be said, that the storage time significantly affects the amount of considered bacteria in fermented dairy products, but the legislative limits were met even at their expiration date. The amount of bifidobacteria in the baby food also matched the declared values. The storage temperature did not affect the amount of considered bacteria observed effect, however there was one exception. Storage of fermented dairy products at lower temperature can be recommended for customers. It is also desirable to consume these foods as fresh as possible.
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Význam a využití rodu Bifidobacterium
Křupalová, Alena
This bachelor thesis titled The meaning and use of the genus Bifidobacterium is divided into three main sections. The first one is dealing with the characteristics of the genus Bifidobacterium. It summarizes taxonomic status, morphology, growth conditions and characteristics of bifidobacteria. There are the most important representatives of this species too. The second section is focusing on microbiological and also analytical determination of bifidobacteria. Cultivation conditions, culture media and analytical methods are depicted under this part. The third section describes the use of the genus Bifidobacterium in practice, which is primarily related to the beneficial effects on human health.
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Survival of bifidobacteria in digestive tract of adult volunteers
Morgensternová, Tereza ; Vlková, Eva (advisor) ; Jitka, Jitka (referee)
Probiotics are living microorganisms, which contribute to health improvement.
The bacteria of the genus Bifidobacterium are one of the most commonly used probiotics. These bacteria are naturally occurring especially in the digestive tract of mammals. They affect the digestive process by helping to optimize the composition of the intestinal microbiota. The probiotic bacteria are expected to survive in the digestive tract and to be able to colonize the intestinal mucosa. The aim of this diploma thesis was to test bifidobacteria of different origin for certain functional properties. Three strains of bifidobacteria were selected: Bifidobacterium animalis ssp. lactis DAN (isolated from Danone yoghurt), Bifidobacterium bifidum JKM (isolated from infant feces) and Bifidobacterium longum ssp. suis 5/9 (isolated from feces of a calf);
and tested in vitro a in vivo. The ability to survive in simulated conditions of digestive tract was tested. The bifidobacteria were exposed to low pH and bile salts. All the strains survived the conditions in unaltered amount till the end of the test. Autoaggregation was observed
as well. The strain Bifidobacterium animalis ssp. lactis DAN showed average autoaggregation only 7,69 %. The other two strains had average autoaggregation 16,10 % and 79,05 %.
The autoaggregation correlated with adherence. Adherence was tested on intestinal cell lines
HT-29, Caco-2 and HT29-MTX, which differed in their ability to produce mucin. The strain Bifidobacterium bifidum JKM showed the best ability to adhere to intestinal cells among all the tested bifidobacteria. They best adhered to Caco-2 cells.
Further, it was necessary to determine if the in vitro study is in correlation with in vivo testing and the bifidobacteria strain with the best ability to adhere will survive in the digestive tract of adult volunteers for the longest time. Rifampicin resistant variants of tested bacteria were given to adult volunteers to distinguish the introduced bifidobacteria and
the bifidobacteria naturally occurring in intestine. All the tested bacteria survived the passage through the digestive tract in large numbers (106 a 107 KTJ/g), the bacteria were not detected 12th day after the introduction. None of the strains is able to permanently colonize the colon of the volunteers. The hypothesis was not confirmed that the most adherent strain
in the digestive tract will survive the longest.
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Characterization of bifidobacteria and lactobacilli isolated from intestinal tract of wild pigs
Šimurka, Julius ; Rada, Vojtěch (advisor) ; Švejstil, Roman (referee)
The microbiota of the gastrointestinal tract is considered as "acuqrated organ" located in a host organism. There are many performs of specific functions. The microbiota composition changes during the life of the individual, depending on his environment and nutrition. The process of identification and characterization of the bacteria from the intestinal microbiota is an important prerequisite for understanding the function of this "acuqrated organ".
This work deals with the anatomy and physiology of the digestive tract (DT) of pigs and evolutionary and eating differences of wild and domesticated pig, for understanding the natural environment of bacteria from DT, which in turn affects the bacterial diversity of the intestinal microbiota. Also mentioned is the process of domestication, which influenced the present form of domestic pig. The work includes the characteristics of lactobacilli and bifidobacteria, which contains the descriptions, taxonomy, metabolism and habitats. The work also shows the insulating media used in practice for the isolation of bifidobacteria and lactobacilli from DT of pigs and methods of their identification and related methods of characterization.
The available literature confirms the differences in the composition of microbiota DT between wild and domesticated pig, that correlate with other studies which study microbiota diversity of other domesticated and wild animals. The diversity studies of humans microbiota, also confirms the broad spectrum of bacterial species in primitive tribes of humans compared with urbanized man.
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Effect of prebiotics on survival of bifidobacteria in digestive tract
Štěrba, Vojtěch ; Vlková, Eva (advisor) ; Jitka, Jitka (referee)
The gastrointestinal microbiota of livestock is a complex and diverse ecosystem, which strongly depends and correlates with animals health. One of the many ways, how to improve the composition of this microbiota in the gastrointestinal tract, is application of probiotics, prebiotics or an appropriate combination called as synbiotics. Using subtle interventions can be achieved health benefits, increase
of some indicators livestock performance and improving the economic situation
of farming.
The aim of the thesis was to find out the effect of prebiotics on the currently applied probiotics and the composition of the intestinal microbiota. Three groups
of calves were studied. In the first one the mixture of five strains of rifampicin resistant variants of Bifidobacterium (RRBif): Bifidobacterium animalis ssp. animalis (2 strains), B. choerinum, B. thermophilum and B. longum ssp. suis was fed to 2 days old calves in a form of fermented milk. In the second group probiotics were adminestered together with prebiotics mixture contains fructooligosaccharides and galactooligosaccharides everyday. The third group without synbiotic treatment was used as a control. The numerous of main bacterial groups in gastrointestinal tract were determined by cultivation.
Our results showed that applied bacteria were able to survive the passage through the gastrointestinal tract of calves. Administered bacteria persist in counts more than 107 CFU/g in the group of calves, that were fed only by probiotics and in numbers 108 CFU/g in the group of calves, that were treated by synbiotics. Furthermore a slow decrease of bifidobacterial numbers to 104 CFU / g was observed in both groups. Significant difference (p = 0.05) between the count of RRBif in probiotic and synbiotic group were determined only two days after administration of that additive. Administration of probiotics and synbiotics to calves increased the count of naturally occurring bifidobacteria, but these differences were not significant.
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Bifidobacteria of intestinal tract of exotic animals
Máčalíková, Tereza ; Vlková, Eva (advisor) ; Salmonová, Hana (referee)
The main topic of the bachelor thesis is description of occurence of bifidobacteria in the gastrointestinal tract of exotic animals and insect.
Afterwards was described a role of probiotic bacteria and influence of nutrition on their occurence. The goal of the practical part of the bachelor thesis was genus-level identification of bifidobacteria in feces samples of exotic animals. After the bacteria cultivation on selective agars, isolates were collected and detection of the enzyme fructose-6-phosphate phosphoketolase were made.
Bifidobacteria were found just in two samples from analyzed animals.
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Degradation of complex carbohydrates by bifidobacteria
Makovská, Marie ; Bunešová, Věra (advisor) ; Švejstil, Roman (referee)
In my bachelor thesis I discuss different strains of bifidobacteria and their ability to utilize different complex carbohydrates as an energy source. For this bachelor thesis were used 112 strains of Bifidobacterium genus which came from different ecological niches. Official collection type and untyped strains were used, along with wild strains, some of which have been isolated by workers and students of the Faculty of Microbiology, Nutrition and Dietetics at the Czech University of Life Sciences. Pure cultures were inoculated into media enriched with different substrates (3 types of starch and Nutriose - resistant dextrin), while tested substrates were always sole carbon sources. Media contained bromcresol red as a pH indicator. A positive sample of the culture, which was able to utilize the substrate, exerted a color change, because of the formation of metabolites (especially acetic acid and lactic acid), which was resulted in lowering the pH.
Further, cultures were tested for ability to degrade starch with so-called plate method. Petri plates contained an agar enriched with starch and tested Bifidobacterium strains were inoculated in preformed holes. After an anaerobic cultivation, coloration by Congo red agent and rinse by NaCl, bright zones around the samples, which prove ability to degrade starch by the bifidobacteria culture, were evaluated.
By the evaluation of the tests has been found that degradation of starch is more frequent for animal strains (which are more species-diverse). Positively respond 59,7 % of total 61 animal strains (20 different species of total 35). Strains isolated from human sources have less capacity of starch degradation. There 26 % of total 42 strains were able to degrade starch. However these positive strains include 8 different species of total 14 tested. From 6 dietary sources of strains just 2 strains (2 different species of 4 tested) were able to degrade starch. One of them was isolated from probiotic product (drops) and the second one was isolated from airag (Mongolian traditional fermented drink, which is made from the milk of mares). All three strains, which were isolated from sewage, can degrade starch (each of them was different species).
The results suggest that some substrate preference of Bifidobacterium strains depends of their habitat.
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Fiber and its consumption on a hospital bed
KŘÍŽKOVÁ, Ivana
The theme of the bachelor thesis is Fiber and its consumption on a hospital bed. Dietary fiber is defined as a carbohydrate food ingredient that cannot be transformed by one´s own enzymes. Fiber was originally considered a ballast food component. Gradually, it was found that it is a part of food fermented by colonic bacteria. Fiber is substrate for these bacteria and they transform it into substances intended for human organism. Fiber can be divided into soluble and insoluble. Both types are essential for human nutrition. A recommended fiber intake for an adult is 30 g per day. In the practical part of the bachelor thesis, was used qualitative research method. The research sample consisted of hospital two-weeks menus. One diet was applied in the hospital facility in the Central Bohemian region and one in the South Bohemian region. Using a computer program "Nutriservis Professional" I calculated the fiber content in the individual meals. The findings were compared with the recommended daily intake published in the book called Referenční hodnoty pro příjem živin and S výživou po celý rok. I also calculated energy value, amount of proteins, fats and carbohydrates of the menus. The results were compared with the recommended values. As a research I interviewed the nutritional therapists in the hospital facilities about the patient´s diet and possible solutions to health problems caused by a lack of fiber. The interviews consisted of eight open questions focused on the fiber consumption, denying of foods containing fiber. The results of calculation previewed the menu at the first hospital facility that fiber deficiency occurs primarily in a liquid diet, while for rational diet, diabetic diet and for infants and older children the fiber content is sufficient. The menu of the other hospital contains insufficient amount of fiber, especially for diabetic diet or geriatic diet reducing fat. On the other hand, diabetic diet contains a plenty of fiber. The interviews that were supposed to find out how nutritional therapists approch the fiber issues in diets brought similar responses. The hospital in the Central Bohemian region include into the diet especially fruit, vegetable, whole grain products and legumes. Older patients ages constipation suffering from bowel obstuction, intestinal disease and flatulence frequently refuse fiber, especially legumes. If a patient has health problems caused be the lack of fiber nutritional therapists usually solve this problem by education and inclusion of fruit, vegetable and whole meal bread into the patient's diet. The hospital in the South Bohemian region frequently include into the diet potatoes, rice, fruit, legumes, vegetable and whole grain breads. Fiber is often rejected by older people and people suffering from diarrheal diseases. Health problems resulting from the lack of fiber are often solved by recommending by foods containing fiber or the nutritional supplements such as NutriFibre.
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