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Identification of lactic acid bacteria in hard cheeses using amplification methods
Herzogová, Jitka ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
Diploma thesis was focused on identification of lactic acid bacteria of species Lactococcus lactis and subspecies Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris using species and subspecies specific polymerace chain reaction (PCR). PCR method was used for identification of bacteria of species Lactococcus lactis in 10 samples of hard cheeses. The method of sample preparation was evaluated for hard cheeses with the aim to receive sufficient amount of cells for the preparation of crude cell lysates. Whole DNA in quality suitable for PCR was separated using magnetic microspheres P(HEMA-co-GMA) in the presence of polyethylenglycol (PEG 6000) and sodium chloride. DNA isolated by phenol extraction was used as control of DNA isolation. PCR was used to the analysis of 7 strains of Lactococcus lactis from Collection of dairy microorganisms Laktofora (CCDM). Altogether 5 or 2 strains were identified into subspecies Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris, respectively.
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Identification of lactic acid bacteria in fermented dairy products using amplification methods
Tycová, Martina ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
Polymerase chain reaction (PCR) is molecular diagnostic method which allows the identification of lactic acid bacteria used in food industry. In this work species-specific PCR primers (targeted on highly conserved 16S rDNA region) were used for identification of bacteria of species Streptoccocus thermophilus in 10 randomly commercially accessible fermented milk products and for identification of species Streptococcus thermophilus in 25 lyophilisates collected in Culture Collection of Dairy Microorganisms Laktoflora (CCDM, Tábor, Czech Republic). The PCR products (968 bp) were detected using electrophoresis in 1,2 % agarose gel. Bacterial DNA was isolated from crude cell lysates by magnetic carriers P(HEMA co GMA) containing carboxyl groups. DNA was reversibly bind on their surface in the presence of high concentrations of poly(ethylene glycol) (PEG 6000) and sodium chloride. Phenol extraction of DNA was used as control. Streptococcus thermophilus strains were identificated using PCR in all analysed samples.
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Microbiological analytical methods suitable for dairy industry
Vlasák, Jaroslav ; Illková, Kateřina (referee) ; Trachtová, Štěpánka (advisor)
The theoretical part of the thesis is focused on probiotics in dairy products. Thesis deals with molecular genetic methods, which are used to analyze DNA. Especially are discussed methods used for isolation bacterial cells belonging to genus Lactobacillus. The polymerase chain reaction (PCR) is the basic technique at present time. Short chain of oligonucleotide primers are used to amplification specific parts of DNA molecule chain. The practical part of the thesis is focused on the DNA from pure bacterial culture and probiotic dairy product. DNA was isolated using methods of phenol-chloroform extraction and magnetic separation. For magnetic separation was used magnetics particles covered with carbonyl functional groups. Quality of the DNA was confirmed by PCR amplification. Primers specific for domain Bacteria and genus Lactobacillus and Bifidobacterium was used.
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Real-time PCR and it´s use in food processing
Tomanová, Barbora ; Pravečková, Martina (referee) ; Trachtová, Štěpánka (advisor)
Polymerase chain reaction (PCR) is a method abundantly used in molecular diagnostics. PCR in real time or quantitative PCR (qPCR) is one of its modifications and thanks to its advantages it finds still wider utilization nowadays. It finds its use in the food-processing industry too with relatively precise detection, identification, and qualification of both desirable and undesirable components in food, which often brings considerable difficulties and leads to an intensive development of this method. In the experimental part a DNA was isolated from dairy product Bio Via Natur drink for its further processing by means of PCR and gain more detailed information about a bacterial composition using real-time PCR and HRM analysis.
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Probiotics and prebiotics in food and other products
Langová, Denisa ; Havlíková, Šárka (referee) ; Trachtová, Štěpánka (advisor)
Theoretical part of this thesis focuses on present state and research of probiotics and prebiotics, their use for microflora modulation of host and their beneficial effects on the health of individuals. Furthermore thesis deals with efficiency of probiotics strains, which depends on the food matrix and other various factors. The experimental part focuses on the identification of chosen bacterial strain, which is contained in probiotics product. It is realized due the isolation of bacterial DNA by phenol extraction and by use of magnetic particles and subsequent analysis of obtained DNA by polymerase chain reaction (PCR).
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Probiotics and their use in food industry
Diado, Aleksandra ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
Probiotic bacteria are defined as live microorganisms, which when consumed in the determining quantities, have healthy and beneficial effects. Most of probiotics belongs to the genera Lactobacillus and Bifidobacterium. These and other genera of microorganisms are successfully used in industry, including food industry at present. Probiotics are used primarily in dairy products and food additives in food idustry. Probiotic bacteria, like other organisms, can be to identifie by PCR method that allows amplifying specific regions of DNA. Polymerase chain reaction was performed after DNA isolation from bacterial cultures of three strains using phenol extraction method. PCR specific for the domain Bacteria and genus-specific PCR were used for the confirmation of the presence of bacteria of the genus Lactobacillus.
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Probiotic lactic acid bacteria in food products
Sásková, Denisa ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
In food industry molecular genetic methods based on DNA analysis are used for identification of probiotic microorganisms. An example of these methods is the polymerase chain reaction, in which specific fragments of DNA are amplified using short oligonucleotide primers. The teoretical part of this bachelor thesis follows probiotic bacteria, their features, beneficial health effects and use in food and clinical applications. The experimental part of the thesis focuses on an analysis of two probiotic dietary supplements. DNA was isolated from these products by method of phenol extraction. The use of PCR confirmed the presence of DNA of probiotic bacteria of genera Lactobacillus and Bifidobacterium.
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Application of real-time PCR in microbiological analysis of food-stuffs
Novotná, Eva ; Michaela, Kotianová (referee) ; Španová, Alena (advisor)
Probiotic lactic acid bacteria of genus Lactobacillus play an important role in the digestive tract of human, e.g. protect against pathogenic microorganisms. Lactobacilli are often present in various food products. Lactic acid bacteria of the genus Lactobacillus can be detected by polymerace chain reaction (PCR) using specific primers LbLMA1 and R16. The bacterial DNA was isolated from Actimel Natur probiotic product by the phenol extraction method. DNA was amplified using real time PCR. Specific PCR products were detected using fluorescent intercalaction dye SybrGreen. The specific PCR products were verified by melting curve analysis (Tm 85°C) and by agarose gel electrophoresis (PCR products of 250 bp was amplified).
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