Browsing by Subject "probiotic"
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(2024)In recent years, consumer interest for probiotic products has significantly grown due to their health benefits, however challenges regarding viability and controlled release of probiotic bacteria during their processing and storage still exist. Microencapsulation of probiotics by spray drying with a suitable protective material could alleviate these challenges. This research aims to assess the viability of utilizing wood hemicelluloses recovered from forest industry side-streams, specifically galactoglucomannans (GGM) and glucuronoxylans (GX), as protective agents for the probiotic strain Lacticaseibacillus rhamnosus GG (LGG) during spray drying. The study results were compared to those of maltodextrins, considering varying solid concentrations (15 and 20%) and inlet air drying temperatures (105 and 140 oC). Feed dispersion properties including viscosity, pH, particle diameter and physical stability were determined. The probiotic's viability pre- and post-spray drying was evaluated, alongside powder characterization for moisture content, water activity, particle size, morphology and structure. Results indicated that both GGM and GX effectively shield LGG from heat impact during spray drying, yielding microcapsule powders with desirable attributes such as amorphous structure and low water activity. High encapsulation efficiency (>90%) comparable to maltodextrins suggested hemicelluloses as sustainable alternatives for conventionally used wall materials. Inlet air temperature or solid concentration did not affect encapsulation efficiency of hemicelluloses. Probiotic counts met a recommended level for probiotic products, signifying potential applications in food and pharmaceuticals. Powder yield, which varied between 35 and 58%, was significantly influenced by the encapsulating material. Morphological studies demonstrated well-formed, spherical particles at a specific drying temperature. The study proposes the potential use of wood hemicelluloses for effective probiotic protection, offering new possibilities for synbiotic powder applications in diverse industries due to their prebiotic properties which have been well reported in literature. Despite promising results, long-term stability and process optimization to improve the process yield and achieve lower moisture content for the microcapsule powders require further investigation. Adjusting feed dispersion parameters and exploring varied concentrations of hemicelluloses could enhance product yield. Meanwhile, increasing outlet air temperature possibly reduces the moisture content. This research fosters sustainable development in the forest industry, presenting a novel avenue for natural functional ingredient production.
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(2024)The porcine gut microbiome is a complex mixture of diverse microbes. During some diseases, the microbial balance of the gut can be disturbed, and harmful bacteria might multiply to concentrations that are harmful to health. To restore balance, the increase of beneficial bacteria that have probiotic potential plays a big role in avoiding the use of antibiotics. In order to develop a probiotic product containing these beneficial bacteria, it is necessary to concretely isolate them from a fecal sample. In this pilot study, the aim was to find an optimal selective growth medium that would allow to grow bacterial species with probiotic properties serving as a potential product in pigs and which would reduce the growth of redundant bacteria. A total of 12 different media were tested with four different sole carbon sources in M9 minimal salts, of which four being supplemented with volatile fatty acids were further tested. The results suggest that cellobiose or xylose could be the best alternatives of the investigated carbon sources for the species of interest. In addition, it was found that certain volatile fatty acids can inhibit the growth of Escherichia coli and several species of the genus Bacteroides.
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(2012)The literature review describes the characteristics, uses and probiotic potential of propionibacteria and gives an overview of proteomic methods focusing on 2-DE studies related to probiotic bacteria and P. freudenreichii. The aim of the experimental part was to use 2-DE to obtain proteome maps of two strains of P. freudenreichii and detect inter-strain differential protein expression. The influence of a number of parameters on the quality of 2-D gels was also investigated. The pH 3-7 and pH 3-11 NL proteome maps obtained displayed 305 and 356 spots, respectively, and detected the differential expression of 60 and 72 spots, respectively. The 3-11 NL proteome map showed spot over-crowding in the pH 4-6 region. Addition of 50 mM dithiothreitol (DTT) to the samples prior to isoelectric focusing (IEF) and an increase of IPG buffer concentration greatly improved spot resolution. Silver staining achieved higher spot counts than Coomassie staining. The influence of the number of lysis cycles on protein extraction was marginal, while lower protein sample loads produced superior 2-D gels. Results show that data from 2-DE proteome maps can provide an overview of inter-strain differential protein expression in P. freudenreichii. The optimal 2-DE experimental setup would include pH 4-7 IPG strips, a low protein load and inclusion of DTT in the IEF sample, as well as silver staining for spot visualisation.
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(2019)Fecal microbiota transplantation (FMT) is a medical treatment procedure in which feces of a healthy donor are transplanted into a recipient in order to re-establish a healthy gut microbiota. Currently, FMT is used routinely to treat recurrent Clostridioides difficile infections, but it is being studied as a potential treatment for other diseases also resulting from a disbalance in the gut microbiota. FMT provides an excellent platform for studies addressing the determinants of a healthy gut microbiota, as it makes it possible to survey specific microbes involved in the process of re-establishment. In this sense, one particularly interesting group of gut microbes is the bifidobacteria. Although usually associated with commercial probiotics, bifidobacteria are actually one of first major colonizers of the human gut after birth, and they play a key role in the establishment and maintenance of a healthy gut microbiota. The aim of this study was to assess the long-term colonization of donor-derived bifidobacteria in recipients of FMT by using a combination of a culture-dependent method and molecular typing of strains. The culture-dependent method was used for the isolation of bifidobacterial strains from fecal samples of donors and recipients, whereas the molecular typing methods (rep-PCR and whole genome sequencing) were employed to differentiate the isolated strains. This study was based on the premise that in order to be of donor-origin, a bifidobacterial strain must occur in the recipient only after FMT and show close genetic relatedness to a strain isolated from the respective donor. Furthermore, in order to exhibit long-term colonization, a donor-derived strain must be present at later time points of the study’s follow-up period. The results showed that all the recipients had acquired some donor-like bifidobacteria after FMT. In addition, certain donor-derived strains of Bifidobacterium longum had persisted in some recipients throughout the follow-up period, indicating their successful colonization. This finding is of special interest, as extraneous bifidobacteria, such as probiotics, are typically lost without their continuous influx. Additionally, long-term colonization of bifidobacteria has not previously been documented in adults by a culture-dependent method. As efficient colonizers, the strains isolated in this study represent potential candidates for therapeutic agents.
Now showing items 1-4 of 4