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1
Fong, Long-yan, und 方朗茵. „Immunomodulatory properties of probiotic bacteria“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/208173.
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Probiotics are living microorganisms, which when administered in adequate amounts confer a health benefit on the host. They have been reported to relieve acute diarrhoea, atopic dermatitis and irritable bowel syndrome in disease-specific animal studies and in human intervention trials. However, probiotics are regularly consumed by general healthy population with limited knowledge in the immunomodulation of probiotics of local and systemic immune responses in healthy experimental models. Serving as the first line of defense against microbial infections and the largest immunological organ in animal host, the epithelium lining the small and large intestine is supposed to be the first organ to encounter probiotics as probiotics are always orally taken. It is believed that probiotics regulate the local immunities in the gut, which acts as the pivot in modulating the systemic immune responses. Accordingly, it was hypothesized that probiotic bacteria can modulate both local and systemic immune responses in healthy population; and the immunomodulation of combination of probiotics is different from that of individual strains. Wildtype healthy C57BL/6 mice were fed with different probiotic strains − Lactobacillus rhamnosus GG (LGG), Lactobacillus rhamnosus LC705 (LC705), Bifidobacterium breve Bb99 (Bb99), Propionibacterium freudenreichii ssp. shermanii JS (PJS) or Escherichia coli Nissle 1917 (EcN), or mixture of probiotics − GGmix (LGG, LC705, Bb99 and PJS) and ECPJSmix (PJS and EcN), for three weeks. After that, intestine, liver, spleen and blood were investigated. Probiotics suppressed intestinal T helper (Th)17 immune response but enhanced systemic (hepatic and splenic) Th17 immune response, suggesting that immune homeostasis was maintained in healthy individuals.
Mechanism of action of LGG was further studied in this project as LGG is the widely studied probiotics. It was hypothesized that LGG exerts immunomodulatory effects by bacteria cells and/or its derived soluble factors such as lactic acid. Immunomodulatory effects of LGG cells and their soluble factors on dendritic cells (DCs), macrophages and monocytes from healthy blood donors were investigated as antigen-presenting cells (APCs) are pivots of bridging innate and adaptive immunities. Cytokine secretion profile, expressions of toll-like receptors (TLRs) and activation-related receptors of the APCs were examined. Both LGG cells and their soluble factors promoted type 1-responsiveness while soluble factors promoted type 17-responsiveness as well. Yet, lactic acid seemed not to be the one which enhanced type 1 and type 17 immune responses in soluble factors. With better understanding on the immunomodulation of probiotics in healthy models, prophylactic efficacy of probiotics in preventing infections and diseases can be availed.published_or_final_version
Biological Sciences
Doctoral
Doctor of Philosophy
2
Drakoularakou, Alexandra. „Synbiotic studies on selected probiotic bacteria“. Thesis, University of Reading, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493809.
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One important development which has recently started to be incorporated to the group of functional foods, is that of the synbiotics (combination of probiotics with prebiotics). This study focused on the development of synbiotic versions of three potential probiotic strains (Lactobacillus acidophilus 74-2, Lactobacillus casei 163 and Bifidobacterium lactis 420) with potential prebiotics and their antipathogenic effects were also investigated. The probiotic characteristics of each of the three strains were assessed prior to investigation of potential synbiotic combinations.
3
Adebayo, Olajumoke O. „Evaluation of bacterial polymers as protective agents for sensitive probiotic bacteria“. Thesis, University of Wolverhampton, 2018. http://hdl.handle.net/2436/621096.
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Probiotics are live microorganisms which when administered in adequate amounts confer one or more health benefits on the host. Different processing conditions, the acidic condition of the stomach and exposure to hydrolytic enzymes affect the viability and efficacy of probiotic organisms. This study investigated the protective effects of two biopolymers poly-gamma-glutamic acid (γ-PGA) and bacterial cellulose (BC) on probiotics during freeze drying and during exposure to simulated intestinal juices and bile salts. The antibacterial property of Bifidobacterium strains was also investigated against four pathogenic bacteria. γ-PGA, a naturally occurring biopolymer was produced by two bacteria (Bacillus subtilis ATCC 15245 and B. licheniformis ATCC 9945a) in GS and E media, γ-PGA yields of about 14.11g/l were achieved in shake flasks and molecular weight of up to 1620 k Da was recorded, γ-PGA production was scaled up in a fermenter with B. subtilis using GS medium. BC, an edible biopolymer was produced by Gluconacetobacter xylinus ATCC 23770 in HS medium and a modified HS (MHS) medium. A yield of about 1.37g/l was recorded and BC production with MHS medium was used for probiotic application. B. longum NCIMB 8809 B. breve NCIMB 8807 and B. animalis NCIMB 702716 showed the best antimicrobial properties against the investigated pathogens. Survival of Bifidobacterium strains was improved when protected with powdered BC (PBC) although γ-PGA offered better protection than PBC. Viability of B. longum NCIMB 8809, B. breve NCIMB 8807 and B. animalis NCIMB 702716 in simulated gastric juice (SGJ) and simulated intestinal juice with bile salts was improved when protected with 5% γ-PGA and 5% γ-PGA+PBC with a reduction of < 1 Log CFU/ml while a reduction of ≤2 Log CFU/ml was recorded in PBC protected cells. Protecting Bifidobacterium strains with γ-PGA, PBC or a novel γ-PGA + PBC combination is a promising method to deliver probiotic bacteria to the target site in order to confer their health benefits on the host.
4
Hamad, Shwan Abdullah. „Novel techniques for microencapsulation of probiotic bacteria“. Thesis, University of Hull, 2012. http://hydra.hull.ac.uk/resources/hull:6873.
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Microencapsulation of living cells such as probiotic bacteria can be used for the protection of the cells from harsh conditions such as low pH and mechanical stress in the digestive system. In this thesis we demonstrate various novel strategies to microencapsulate living yeast cells as a model for probiotic bacteria. We prepared and used sporopollenin microcapsules to encapsulate yeast cells by compressing the sporopollenin particles into a pellet which was exposed to an aqueous suspension of yeast cells in the presence of a biocompatible surface active agent. We also demonstrate that the viability of the cells is preserved after the microencapsulation. We fabricated novel shellac-yeast cells composite microcapsules programmed to release the cells upon change of pH in a narrow range. This was achieved by either spray drying or sprays co-precipitating dispersion of yeast cells in aqueous solution of ammonium shellac doped with a pH-sensitive polyelectrolyte. We also demonstrate that yeast cells retain their viability even when treated with aqueous solutions of low pH. In addition, the pH-triggered release of yeast cells from these composite microcapsules and their disintegration rates were investigated. We developed a theoretical model for the kinetics of yeast cells release from the microcapsules triggered by (i) pH change and (ii) the growth of the cells in a culture media. In a separate strategy of microencapsulation of living cells, we used templates of Pickering emulsions stabilised with latex nanoparticles to fabricate colloidosomes loaded with viable probiotics. Depending on the method of transfer, we have shown that magnetic colloidosomes containing pH-sensitive polyelectrolyte loaded with living cells can be prepared using Pickering emulsion templates. In addition, we demonstrate two strategies to strengthen the stability of water-in-oil Pickering emulsion droplets by interlocking the adsorbed latex particle monolayer: by (i) using oppositely charged polyelectrolyte adsorption or (ii) using polyelectrolyte pre-coated yeast cells which act as cross-linkers inside the water-in-oil droplets. Furthermore, we report the fabrication of 3 D multicellular cellosomes of living cells by using water-in-oil emulsion templates as intermediate. We have used two strategies to assemble yeast cells pre-coated with polyelectrolytes in water-in-oil emulsion droplets stabilised with either surfactant or solid particles. The emulsion droplets containing oppositely charged yeast cells linked together by electrostatical interactions were shrunken to compact structures upon addition of dry octanol and subsequently transferred into water to fabricate cellosomes. In summary, this thesis contributes an arsenal of new methods for microencapsulation of living cells for the purpose of their protection and triggered release. The results of this thesis can be used in the formulation of better probiotic products, protection and release of cells implants, tissue engineering and development of live vaccines.
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Dixit, Sameer M. „Antagonistic activity of probiotic bacteria based on bacterial diversity in the porcine gut“. Thesis, View thesis, 2004. http://handle.uws.edu.au:8081/1959.7/35614.
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Diversity analysis of Escherichia coli have routinely utilised isolates obtained by culture of faeces on MacConkey selective media, under the assumption that the diversity identified in faecal isolates are representative of similar diversity in E. coli in the gastrointestinal tract (GIT). This study has addressed this important issue by specifically isolating E. coli from different regions of the gut in pigs and subjecting them to enzymatic multilocus enzyme electrophoresis (MLEE) and molecular virulence factor (VF) analysis to ascertain whether E. coli populations inhabiting different regions of the gut are different from each other. Combination of these results showed that on average, E. coli strains isolated from the upper GIT region (small intestine) of the pig are distinctly different from the E. coli strains isolated from the lower GIT region (large intestine). An important aspect of the finding that faecal E. coli are not truly representative of the diversity in the GIT is the mechanism used by specific clonotypes that have adapted to different geographical habitats to survive challenge from incoming strains.
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Dixit, Sameer M. „Antagonistic activity of probiotic bacteria based on bacterial diversity in the porcine gut“. View thesis, 2004. http://handle.uws.edu.au:8081/1959.7/35614.
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Thesis (Ph.D.)--University of Western Sydney, Hawkesbury, 2004.A thesis presented to the University of Western Sydney, Hawkesbury, Centre for Advanced Food Research, in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliographies.
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Jones, Mitchell. „Enzymatically active probiotic bacteria for topical and oral therapy“. Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103498.
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A novel approach whereby one can use probiotic bacteria for the purpose of topical and oral therapy is presented. More specifically, a treatment modality using enzymatically active probiotic production of gaseous nitric oxide (gNO) for wound healing, antimicrobial, cosmetic, and dermatologic therapy is presented. In another aspect, a probiotic treatment modality for metabolic disease and metabolic syndrome using nitrate reductase (NiR) active probiotic bacteria is explored. In concurrence to these requirements, several in-vitro methods are designed and discussed in this report. For some of these studies the use of alginate microcapsules is explored. Results show that probiotic patches can be used for the production of gNO above therapeutic levels and for therapeutic durations and that probiotic gNO-producing patches are highly bacteriostatic, bactericidal, and fungicidal. Results show that the novel gNO-producing probiotic patch can be used to improve wound healing and increase the likelihood of wound closure in ischemic and infected full-thickness dermal wounds in a New Zealand White Rabbit model and that daily application of the patch is safe with respect to body weight, blood morphology, haematology, blood biochemistry, and methemoglobin levels. Also, results show that novel NiR-active probiotic bacteria can be selected for nitrate reductase (NiR) activity in-vitro, and can be microencapsulated or delivered free under simulated GI conditions, and in the presence of various food matrices while maintaining NiR activity, confirming the lab scale feasibility of the approach in delivering the probiotic orally for treating hypertension, inflammatory bowel disease, gastric ulcers, diabetes and thrombosis. These findings may provide effective, safe, and less costly alternatives for delivering gNO topical and oral for therapy.Une nouvelle approche selon laquelle on peut utiliser des bactéries probiotiques dans le but de la thérapie topique et de la thérapie par voie orale est présentée. Plus précisément, une modalité de traitement, utilisant des probiotiques à activité enzymatique produisant de l'oxyde nitrique gazeux (NOg) pour la cicatrisation des plaies, ainsi que comme thérapies antimicrobiennes, cosmétiques et dermatologiques, est présenté. Dans un autre aspect, une modalité de traitements probiotiques pour les maladies métaboliques et les syndromes métaboliques en utilisant du nitrate réductase (NiR) bactéries probiotiques actives est explorée. En accord à ces exigences, plusieurs méthodes in vitro sont conçus et discutés dans le présent rapport. Pour certaines de ces études l'utilisation de micro capsules d'alginate est explorée également. Les résultats montrent que les correctifs probiotiques peuvent être utilisés pour la production de NOg au-dessus des niveaux thérapeutiques et pour des durées thérapeutiques et que les patches de NOg-producteurs de probiotiques sont très bactériostatiques, bactéricide et fongicide. Les résultats montrent que les nouvelles patches de NOg producteurs de probiotiques peuvent être utilisés pour améliorer la cicatrisation et augmenter la probabilité de fermeture de la plaie dans les plaies de pleine épaisseur ischémique et infectés par voie cutanée dans un modèle néo-zélandais White Rabbit et que l'application quotidienne des patches est sécuritaire en proportion avec le poids du corps, la morphologie du sang, l'hématologie, biochimie sanguine, et les niveaux de méthémoglobine. En outre, les résultats montrent que les nouvelles NiR-bactéries probiotiques actives peuvent être sélectionnés pour la nitrate réductase (NiR) l'activité in vitro, et peut être micro encapsulées ou remis gratuitement dans des conditions simulées GI, et en présence de diverses matrices alimentaires, tout en maintenant l'activité NiR, confirmant ainsi la faisabilité échelle du laboratoire de l'approche dans la réalisation des probiotiques par voie orale pour le traitement de l'hypertension, les maladies inflammatoires de l'intestin, les ulcères gastriques, le diabète et la thrombose. Ces résultats peuvent s'avérer efficaces, sûrs, et des solutions moins coûteuses pour offrir NOg topiques et oraux pour le traitement.
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Fjellheim, Anders Jon. „Selection and administration of probiotic bacteria to marine fish larvae“. Doctoral thesis, Norwegian University of Science and Technology, Department of Biology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-2217.
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9
Ramiah, Kamini. „Characterization of the adhesion genes of probiotic lactic acid bacteria“. Thesis, Link to the online version, 2008. http://hdl.handle.net/10019.1/1090.
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10
Argin, Sanem. „Microencapsulation of probiotic bacteria in xanthan-chitosan polyelectrolyte complex gels“. College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7826.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Dept. of Nutrition and Food Science. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Brink, Marelize. „Market and product assessment of probiotics and prebiotics and probiotic strains for commercial use“. Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50011.
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Thesis (MSc Nutrition Science)--Stellenbosch University, 2004.ENGLISH ABSTRACT: Probiotics (live microbes) and prebiotics (non-digestible food-ingredients) are rapidly gaining interest worldwide as supplements and functional food ingredients but little South African information in this regard is available. Furthermore, the availability of South African produced probiotic concentrates for commercial use is also very limited. The aims of this study therefore were to complete a market and product assessment of probiotic and prebiotic containing products in South Africa and to evaluate probiotic strains for commercial use in South Africa. For the purposes of market and product assessment probiotic and/or prebiotic containing products manufactured in South Africa were identified. The scientific and legal correctness of health and content claims made on the labels of the products were assessed. An exploratory survey was conducted to determine the awareness of South African consumers of probiotics and prebiotics. For the evaluation of probiotic strains for potential commercial use in South Africa, a panel of twelve lactic acid bacteria (LAB) were screened for inhibitory activity against two porcine pathogens and indicator strains from the LMG-panel isolated from the faeces of patients diagnosed with AIDS. The five LAB with the best inhibitory activity were tested for growth in soymilk-base and for the effect of lyophilization on the inhibitory activity thereof. The effect of prebiotics on the growth and inhibitory activity of the strains was tested in vitro. A range of products containing probiotics and prebiotics available on the South African market was identified. Irregulatories concerning health claims on the labels were found, but content claims seemed to be less of a problem. The results also indicate that the proposed South African regulations for the labelling of probiotic and prebiotic containing products need to be revised to include the probiotic and prebiotic related health claims for which sufficient scientific evidence is available. The probiotic strains with potential for commercial use in South Africa that were identified, include Lactobacillus plantarum 423, Lactobacillus casei LHS, Lactobacillus salivarius 241, Lactobacillus curvatus DF38 and Pediococcus pentosaceus 34. These strains were grown successfully in soymilkbase and lyophilization did not have a negative effective on the inhibitory activity thereof. The growth and inhibitory activity of the five LAB were promoted when combined with 1% (w/v) Raftilose® Synergyl . It is concluded that although a variety of probiotic and prebiotic containing products are available on the South African market, the scientific and legislative correctness of especially health related claims is not satisfactory and that South African consumer awareness of these products is low. It is also concluded that a combination of at least three of the five identified LAB and 1% Raftilose® Synergy can be used by South African manufacturers for the production of probiotic and prebiotic containing supplements.
AFRIKAANSE OPSOMMING: Die belangstelling in probiotika (lewendige mikrobe) en prebiotika (onverteerbare voedselbestanddele) as supplemente en funksionele voedselbestanddele is besig om wêreldwyd toe te neem, alhoewel weinig Suid-Arikaanse inligting in hierdie verband beskikbaar is. Die beskikbaarheid van Suid-Afrikaans geproduseerde probiotika konsentrate vir kommersïele gebruik is ook baie beperk. Die doelwitte van hierdie studie was dus om 'n mark- en produkevaluering van probiotika- en prebiotika-bevattende produkte in Suid-Afrika uit te voer en om probiotiese stamme te evalueer vir uiteindelike kommersiële gebruik in Suid-Afrika. Vir die doel van die mark- en produkevaluering is probiotika- en prebiotika-bevattende produkte wat in Suid-Afrika vervaardig word geïdentifiseer. Die wetenskaplike en wetlike korrektheid van die gesondheids- en inhoudsaansprake op die etikette van die produkte is evalueer. 'n Markopname is uitgevoer om die bewustheid van Suid-Afrikaanse verbruikers van probiotika en prebiotika vas te stel. Vir die evaluering van probiotiese stamme vir potensïele kommersiële gebruik in Suid-Afrika is 'n paneel van twaalf melksuurbakteriëe getoets vir inhibitoriese aktiwiteit teen twee patogene geïsoleer uit varke asook teen indikator stamme van die LMG-paneel. Die vyf melksuurbakteriëe met die beste inhibitoriese aktiwiteit is getoets vir groei in sojamelk-basis en ook vir die effek van vriesdroging op die groei en inhibitoriese aktiwiteit van die stamme daarvan. Die effek van prebiotika op die groei en inhibitoriese aktiwiteit van die stamme is in vitro getoets. 'n Reeks van probiotika- en prebiotika-bevattende produkte wat beskikbaar is op die Suid-Afrikaanse mark, is geidentifiseer. Ongeruimdhede met die gesondheidsaansprake op die etikette is gevind, maar inhoudsaansprake was minder problematies. Die resultate dui ook daarop dat die voorgestelde Suid- Afrikaanse regulasies vir die etikettering van probiotika- en prebiotika-bevattende produkte hersien moet word om al die probiotika- en prebiotika-verwante gesondheidsaansprake waarvoor voldoende wetenskaplike bewyse beskikbaar is in te sluit. Die probiotiese stamme met potensiaal vir kommersiële gebruik in Suid-Afrika sluit die volgende in: Lactobacillus plantarum 423, Lactobacillus casei LHS, Lactobacillus salivarius 241, Lactobacillus curvatus DF 38 en Pediococcus pentosaceus 34. Hierdie stamme is suksesvol gekweek in sojamelk-basis en vriesdroging het nie' n negatiewe effek op die groei en inhibitoriese aktiwiteit daarvan gehad me. Die kombinasie van die vyf melksuurbakteriëe met 1% Raftilose® Synergy het die groei en inhibitoriese aktiwiteit daarvan bevorder. Die gevolgtrekking wat gemaak word is dat alhoewel 'n varrasie van probiotika- en prebiotikabevattende produkte beskikbaar is op die Suid-Afrikaanse mark, die wetenskaplike en wetlike korrektheid van spesifiek die gesondheids-verwante aansprake op die etikette daarvan nie bevredigend is nie en dat die bewustheid van die Suid-Afrikaanse verbruikers van hierdie produkte laag is. Die gevolgtrekking kan ook gemaak word dat 'n kombinasie van ten minste drie van die vyf geïdentifiseerde melksuurbakteriëe en 1% Raftilose® Synergy deur Suid-Afrikaanse vervaardigers gebruik kan word vir die vervaardiging van produkte wat probiotika en prebiotika bevat.
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Hart, Ailsa Louise. „Dendritic cells in intestinal inflammation and their modulation by probiotic bacteria“. Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416596.
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Bull, Matthew J. „Molecular genetic characterisation of probiotic bacteria : Lactobacillus acidophilus and Bifidobacterium species“. Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/53985/.
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Over time and concurrent development of methods to identify and characterise bacteria, the lactic acid bacteria (LAB) have undergone multiple taxonomic revisions. As a result of the revisionary nature of LAB taxonomy, the historical characterisation of Lactobacillus acidophilus has struggled with misidentification and misrepresentation. Now however, due to its global use in food products for both flavour and probiotic effect, L. acidophilus is now one of the most well physiologically characterised Lactobacillus species. Bifidobacterium bifidum and Bifidobacterium animalis subsp. lactis are also LAB that are considered to have probiotic effects. Here modern high-throughput next generation comparative genomic techniques are used alongside conventional biochemical and molecular typing methods to analyse the sub-species level diversity of these three probiotic species. Results Randomly Amplified Polymorphic DNA (RAPD) profile similarity analysis showed limited strain-level diversity of L. acidophilus. A species specific marker test was developed for L. acidophilus and used to search for L. acidophilus in wild rodent and human faeces. No L. acidophilus was detected in wild rodent faeces and its carriage in human faeces was highly variable. High-throughput next generation sequencing was used to resequence the genomes of 28 L. acidophilus isolates. Comparing these sequences indicated a high level of genomic conservation in L. acidophilus, which was reflected by limited phenotypic diversity. Comparative genomics in Bifidobacterium animalis subsp. lactis supported the hypothesis that it is a clonally monophyletic species, whereas B. bifidum strains were genomically diverse. Conclusions Methods for phenotypically characterising and typing LAB have generally been superseded in accuracy by DNA sequence based methods. Probiotic bacteria display a range of subspecies level population structures. Commercial and culture collection L. acidophilus isolates did not significantly differ phenotypically, but were distinct when their genome sequences are compared. B. bifidum was genotypically diverse at the subspecies level, while B. animalis subsp. lactis appeared to be clonally monophyletic. Comparative genomics and genome (re)sequencing of probiotic bacteria will become a “gold standard” method for characterisation and typing of isolates.
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Akter, Nousin. „Rheological behaviour of probiotic bacteria dispersed in maltodextrin and sucrose solutions“. Thesis, Malmö universitet, Fakulteten för hälsa och samhälle (HS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-26378.
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Probiotic bacteria are live microorganisms, which manifest health benefits in humans. The goal of this work was to characterize rheological properties of probiotic bacteria (Lactobacillus reuteri) formulation in which maltodextrin and sucrose used as excipients. To fulfil the goal, first, thermal, structural and rheological properties of maltodextrin, sucrose solutions and probiotic bacteria slurry were investigated. Probiotic bacteria formulations were prepared by adding probiotic bacteria slurry to maltodextrin and sucrose solutions at different mass fractions. Finally, rheological properties of probiotic bacteria formulations were evaluated. From TGA, the water content of PB slurry including intracellular water found 81%. In DLS, three different types of aggregations of maltodextrin were observed and characteristic size of Probiotic bacteria found 1μm. The optical microscopy results indicate that at the liquid - air interface and in dehydrated state the bacteria are birefringent and arranged in an ordered fashion resembling a nematic phase. Most of the MD, SU and MD+SU solutions show Newtonian behaviour. MD and SU solutions show strong increase of viscosity with increasing concentration. This dependence can be described by using the Spurlin–Martin–Tennent’s model. The viscosities of MD+SU solutions increase with increasing proportion of maltodextrin. The oscillation data of MD and MD+SU solutions can be described by Maxwell model. The viscosities of MD, SU, MD+SU mixed solutions decrease with increasing temperature. This temperature dependency can be described by Arrhenius model of viscosity. At very high concentrations of MD, a deviation from this behaviour is observed. The probiotic bacteria slurry shows shear thinning behaviour at low shear stress and Newtonian behaviour at higher stresses. All probiotic formulations in which probiotic bacteria dispersed in maltodextrin and sucrose solutions show Newtonian behaviour. The viscosities of maltodextrin solutions and MD+SU mixed solutions decrease by addition of probiotic bacteria whereas mixed effects of probiotic bacteria addition on the viscosity of sucrose solutions were observed. The viscosity of probiotic bacteria slurry decreases with increasing temperature, although deviations from this behavior are seen at certain conditions.
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Rodriguez, Sala Bruno Gomez Gil. „Evaluation of potential probionts for use in penaeid shrimp larval culture“. Thesis, University of Stirling, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244497.
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Páterová, Alena. „Obsah mléčných bakterií ve vybraných typech probiotických potravin“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-216612.
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Probiotics are defined as live microorganisms that have, if ingested, a positive impact on human and animals health. The best known probiotics are the lactic acid bacteria, among them most commonly used are lactobacilli and bifidobacteria. For therapy the minimum daily consumption of at least 100 g of milk product with a minimum 1000000 of probiotic bacteria in 1 g or 1 ml is considered. In this work, several products that have declared on the label probiotic cultures have been selected. All products were analyzed for the number of lactic acid bacteria. Two media - MRS agar and skim milk agar Modified were used for cultivation. Cultivation proceeded at 37 °C for 48 hours under aerobic and anaerobic conditions. Amount of live bacteria, which must be present in the product, indicates Ministry of Agriculture No. 77/2003 Coll.. Quantitative representation of lactic acid bacteria in all selected products comply with the requirements of legislation.
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Carter, Alun James. „An evaluation of the efficacy and safety of probiotic lactic acid bacteria“. Thesis, University of Surrey, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494201.
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This project was undertaken as part of a commercial evaluation of two probiotic strains for subsequent use in the European market. Probiotic bacteria are thought to act as competitive exclusion agents against food home pathogens by several mechanisms. The aim of the study was to characterise the probiotic strains Lactobacillus salivarius 59 and Enterococcus faecium PXN-33, determine the safety of the probiotic strains and to evaluate the strains ability to competitively exclude Salmonella Enteritidis.
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Pispan, Supaporn. „The development of encapsulated probiotic bacteria with prebiotics incorporated into cereal beverages“. Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/9270.
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Most probiotic products are dairy-based and require refrigeration, but there are currently no spray dried probiotic powders sold commercially today. The aim of this research is to develop instant cereal beverage using an oat-based formulation containing the probiotic organism Lactobacillus acidophilus. Escherichia coli K12 was initially used as a reference Gram negative microorganism to compare with the Gram positive L. acidophilus. The work started with the examination of growth to determine the timings required to harvest cells in the mid-log phase and the early-stationary phase of both bacteria. Spray only experiments were then performed which showed that atomisation itself did not cause any significant effect on cell survival of either cultures, either in the mid-log or early-stationary phases. The spray drying experiments found that cells harvested in the early-stationary phase had a greater heat resistance than those cultured in their mid-log phase at the same outlet temperature. It was also found that the higher the drying outlet temperature, the lower was the cell survival rate. The best survival rates were found when spray drying at drying outlet temperatures lower than 80°C. E coli K12 was found to have a lower level of survival than L. acidophilus especially when spray dried with maltodextrin without culture broth components present. This can be attributed to the much thinner cell wall of the Gram negative E coli K12 bacterium. The optimal growth phase (early stationary) and spray drying outlet temperature (80°C) were then taken forward in to the next study for L. acidophilus when various combinations and ratios of proteins (either whey protein, isolated soy protein or skim milk) and sugars (either maltose, lactose or fructose), and maltodextrin were tested. Cell survival rates after spray drying were tested after rehydrating in phosphate buffer solution (PBS), simulated gastric juice (SGI) or 2% Bile solution for 1 hour, although significantly better survival was observed if left to rehydrate for 12 hours. By directly examining experimental data and also using Response Surface Methodology (RSM) it was found that in general increasing the protein level gave a higher cell survival rate after rehydrating in PBS, SGI and bile solution, while formulations containing no protein showed the lowest survival rate. It was strongly shown that the presence of protein above 50%, particularly milk protein, does protect cells in these harsher environments. The sugar contents were limited to a maximum value of 25% due to stickiness limitations. It was found that maltose produced better results than lactose or fructose. Incorporation of a liquid oat drink into the formulation to replace distilled water only produced a slight lowering of survival levels if protein levels were still maintained, but replacing the protein mixture by a prebiotic (Orafti®P95) produced adverse results. After storage for 3 months these spray dried cultures showed high stability when stored at refrigerator temperatures (4°C) although acceptable levels of survival were also found when stored at room temperature. A simulated hydration/digestion was performed by which cells were hydrated in distilled water and exposed to SGI and bile solution in turn. These showed very good results and indicated that the bacteria could be transported to the gut in a viable state. The recommended formulation for spray dried L. acidophilus encapsulated with whey protein, maltose and maltodextrin incorporated into prebiotics and oat drink is 16%, 2%, 2%, 0% and 80% respectively.
19
Kouimtzi, Maria. „Survival of bacteria in pellets, tablets and capsules“. Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325613.
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20
Salame, Joumana. „EVALUATION OF TWO ORAL PROBIOTIC PRODUCTS FOR MICROBIAL VIABILITY AND IN VITRO INHIBITION OF SELECTED PERIODONTAL BACTERIAL PATHOGENS“. Master's thesis, Temple University Libraries, 2011. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/147512.
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Oral BiologyM.S.
Objectives: One potential impact of oral probiotic products involves use of known bacterial antagonisms to alter the ecologic environment in periodontal pockets from one inhabited by pathogenic dental plaque microorganisms to one more favorable to colonization by non-pathogenic species (bacterial replacement). Until recently, the ability to introduce such beneficial effector bacteria into the oral cavity of periodontitis patients has been limited by the lack of specifically-formulated available commercial probiotic products. PerioBalance (Sunstar GUM), with two strains of the gram-positive, aerobic species Lactobacillus reuteri, and EvoraPlus (Oragenics), with freeze-dried strains of the gram-positive, aerobic species Streptococcus oralis, Streptococcus uberis, and Streptococcus rattus, are two recently-introduced commercial oral probiotic products proposed to have beneficial effects against periodontal disease. However, it is not known if the microbial species contained in these two oral probiotics are viable after the manufacturing process, and have the capability to exert inhibitory effects against putative periodontal bacterial pathogens when reconstituted in the oral cavity. Thus, the objective of the present study was to determine whether PerioBalance lactobacilli and EvoraPlus streptococci are viable upon product use, and possess in vitro inhibitory effects against fresh clinical strains of the putative periodontal bacterial pathogens, Tannerella forsythia and Prevotella intermedia/nigrescens, in the presence of anaerobic growth conditions. Methods: Commercial lots of PerioBalanceÒ and EvoraPlusÒ tablets were aseptically removed from the product packaging with sterile forceps, dissolved into Möller’s VMG I anaerobic dispersion solution, plated onto pre-reduced, enriched Brucella blood agar, and subjected to overnight anaerobic incubation at 35ºC in a culture cabinet containing 85% N2-10% H2-5% CO2, and to overnight aerobic incubation in a 5% CO2-95% air atmosphere. All culture plates were then visually examined under magnification for microbial colony growth. In vitro solid media competition assays were used to assess the in vitro inhibition capability of the two oral probiotics against T. forsythia and P. intermedia/nigrescens. Pioneer PerioBalance lactobacilli and EvoraPlus streptococci colonies were first grown on enriched Brucella blood agar media, followed by secondary spotting of T. forsythia and P. intermedia/nigrescens isolates immediately next to the established pioneer EvoraPlus and PerioBalanceÒ bacterial colonies such that they almost touched each other. After an additional overnight anaerobic incubation period, growth inhibition of the putative periodontal bacterial pathogens by the pioneer PerioBalance and EvoraPlus colonies was noted as the visual presence without magnification of a proximal zone of inhibition at the intersection of the pioneer colonies and the T. forsythia and P. intermedia/nigrescens colonies. Results: PerioBalance lactobacilli grew readily and in abundance in vitro on anerobically and anaerobically-incubated EBBA, with no other colony types or contaminating organisms. In contrast, EvoraPlus product samples purchased over-the-counter from drug stores in Maryland and Pennsylvania failed to exhibit any in vitro microbial growth under anaerobic and aerobic incubation conditions, with only EvoraPlus tablets obtained directly from the manufacturer yielding in vitro streptococcal growth. No in vitro inhibition was noted under anaerobic conditions of established PerioBalance lactobacilli and EvoraPlus streptococci pioneer colonies against subsequent growth of clinical isolates of T. forsythia and P. intermedia/nigrescens, with no zone of inhibition developing between their colonies and the immediately-adjacent established oral probiotic pioneer colonies. Conclusions: The two commercial oral probiotics evaluated varied considerably in the viability of their microbial constituents, with abundant growth of PerioBalance lactobacilli found in over-the-counter product material, and the lack of any EvoraPlus streptococci growth in product tablets obtained from sources other than directly from the manufacturer. Both oral probiotic products failed in vitro, in solid media competition assays, to inhibit growth of fresh clinical isolates the putative periodontal bacterial pathogens T. forsythia and P. intermedia/nigrescens under anaerobic growth conditions. These findings question the potential effectiveness of the two oral probiotic products to alter the subgingival ecology in periodontal pockets when anaerobic environmental conditions are present. Additional research is needed to assess the inhibitory potential of PerioBalance lactobacilli and EvoraPlus streptococci against additional isolates of subgingival bacterial species, and in circumstances where microaerophilic or aerobic environmental conditions are found.
Temple University--Theses
21
Charalampopoulos, Dimitris. „Development aspects of cereal-based fermented foods with potentially probiotic lactic acid bacteria“. Thesis, University of Manchester, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488206.
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22
陳怡君 und Yee-kwan Chan. „Modulation of atherosclerosis by probiotic bacteria VSL#3 and LGG in ApoE-/- mice“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hdl.handle.net/10722/193068.
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Atherosclerosis is the major cause of cardiovascular diseases, which constitute the top ten leading causes of death worldwide. Atherosclerotic plaque development initiates from the inflamed endothelium under an atherogenic environment – chronic low grade inflammation, hypercholesterolemia, endotoxemia, etc. The principal cause of such inflammation has yet to be defined – with growing evidence that microbial stimulants like lipopolysaccharide (LPS) and peptidoglycan (PGN), which can activate toll-like receptors (TLRs) and nuclear factor-kappaB (NFκB) signaling might be the plausible origins. The gastrointestinal tract is suggested to be the major site for absorption and translocation of such stimulants, where gut microbiota have been associated with systemic inflammation and is essential in generating atherogenic substances. Since probiotics have the potential to induce systemic anti-inflammatory effects and fortify gut barrier to reduce bacterial translocation, evaluation of whether probiotics can help reduce atherogenesis was done by feeding the disease model, ApoE-/- mice with high fat diet alone, with telmisartan (1 or 5 mg/kg/day, positive controls) or with probiotics VSL#3 (2.8 x 1011 CFU/day) and/or Lactobacillus rhamnosus strain GG (LGG) (1x108 CFU/day), or the combination of which for 12 weeks. All treatments reduced lesion size significantly; with some treatments reduced plasma endotoxin, cholesterol and various proinflammatory biomarkers. The gut microbiota assessed with PCR-amplified 16S rRNA gene sequences using 454 pyrosequencing and thereafter correlation studies revealed that at least 20 bacterial families that were significantly altered by high fat diet in apolipoprotein E knockout (ApoE-/-)mice correlated with atherosclerotic plaque size and related biomarkers including cholesterol, adipocyte fatty acidbinding protein (A-FABP), etc. Probiotics showed potential in improving atherogenic environment by immunomodulation and induction or inhibition of growth of bacteria correlated with the atherosclerotic plaque and biomarkers. The atherosclerotic condition was also improved by telmisartan, which correlated with the altered gut microbiota. The newly identified atherosclerosis-related gut bacteria will require further exploration into their properties and mechanisms, which will eventually lead to the potential of developing probiotics for the treatment or prevention of atherosclerosis, and thus may be used as an affordable and non-invasive alternative that brings health benefits worldwide.published_or_final_version
Biological Sciences
Doctoral
Doctor of Philosophy
23
Whitley, Katherine. „Phenotypic variants of lactic acid bacteria, their metabolism and relevance to probiotic criteria“. Thesis, University of Huddersfield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323780.
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24
De, Bruyn Anneke. „Isolation of potential probiotic and carotenoid producing bacteria and their application in aquaculture“. Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/79852.
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Thesis (MSc)--Stellenbosch University, 2013.ENGLISH ABSTRACT: The ocean’s fish resources are declining mainly because of irresponsible exploitation. Fish is a vital source of protein for humans and growing world populations are threatening the sustainability of commercial fisheries. This has led to the rapid growth of aquaculture worldwide. In South Africa, aquaculture of both fresh and marine species is expanding and is now practised in all nine provinces of the country. One of the major problems in aquaculture is the economic losses as a result of diseases. Viruses, bacteria, fungi and parasites are well known to infect fish, with bacteria causing the majority of diseases. Antibiotics were commonly used to control diseases, however, due to their negative impact on the environment, the use of these agents is questioned. This has led to the search for probiotics as an alternative way to control bacterial diseases in aquaculture. Probiotics used in aquatic environments can be defined as live microbial supplements which have beneficial effects on the host by altering the microbial communities associated with the host and the immediate environment. Probiotics have a variety of different mechanisms of action, including competition with pathogens, production of beneficial compounds, enhancement of host immune response and antiviral effects. This study aimed to isolate potential probiotic bacteria from the gastrointestinal tract (GIT) of the South African abalone (Haliotis midae). Nine different bacterial species were isolated and identified as Corynebacterium variabilei, Staphylococcus carnosus, Staphylococcus equorum, Staphylococcus cohniii, Vibrio aestuarianus, Vibrio nigripulchritudo, Vibrio cyclitrophicus, Photobacterium leiognathi, and Paracoccus marcusii (Chapter 2). One of these isolates, P. marcusii (isolate 6.15), showed promising probiotic properties together with the potential to be used as a pigmentation source due to its production of the carotenoid astaxanthin. Aquatic animals are not able to synthesize astaxanthin and under aquaculture conditions do not come into contact with natural pigment sources. This results in dark grey meat which is unappealing for consumers. Therefore, astaxanthin is included in the feed of a variety of aquaculture species such as salmon, trout, red see bream and shrimp to give the meat a pink/orange colour. Astaxanthin also plays an important role in other essential biological functions of fish such as increasing the defence potential against oxidative stress and enhancing sexual maturity, embryo development, and egg survival. Mozambique tilapia (Oreochromis mossambicus) and rainbow trout (Oncorhynchus mykiss), two important aquaculture species in South Africa, were used to evaluate the probiotic and pigmentation effect of P. marcusii (isolate 6.15). Fish feed was coated with freeze dried bacterial cells (107 CFU/kg feed) and administrated to tilapia and trout. Because tilapia cannot incorporate astaxanthin into their meat, no pigmentation effect of P. marcusii (isolate 6.15) was evaluated for this species. However, tilapia showed significant improvement in growth and immune parameters. Fish supplemented with P. marcusii (isolate 6.15) had a higher percentage increase in body weight and a better feed conversion ratio for the duration of the trial. Enhanced lysozyme activity in the blood serum of the fish was also seen (Chapter 3). In contrast, P. marcusii (isolate 6.15) did not have any probiotic or pigmentation effect on rainbow trout. A possible reason for this may be that the concentration of P. marcusii (isolate 6.15) added to the feed was too low. More probably, it is suspected that no pigmentation was observed due to the destruction of the astaxanthin before being ingested by the trout, because astaxanthin is a very unstable molecule. Furthermore, the GIT microbial communities of trout were investigated over the duration of the trial for the different treatments. No similarities in community structures were observed betwee the different treatments, however, bacterial communities in the GIT of fish sampled at the same time were very similar (Chapter 4).
AFRIKAANSE OPSOMMING: Die oseaan se vis hulpbronne is besig om af te neem as gevolg van die onverantwoordelike gebruik daarvan. Vis is ‘n belangrike bron van proteïene vir mense en die toenemende wêreld populasie bedreig die volhoubaarheid van kommersiële visserye. As gevolg hiervan is daar ‘n drastiese toename in die akwakultuur industrie wêreldwyd. Ook in Suid Afrika brei die akwakultuur van beide vars water en mariene vis spesies uit. Een van die grootste probleme in akwakultuur is ekonomiese verliese as gevolg van siektes wat veroorsaak word deur virusse, bakterieë, fungi en parasiete. Bakterieë veroorsaak die meerderheid van die siektes en antibiotika word algemeen gebruik vir die beheer van bakteriële siektes. Die gebruik van antibiotika word egter bevraagteken omdat dit verskeie negatiewe implikasies vir die omgewing inhou Daarom word probiotika oorweeg as ‘n alternatief tot antibiotika om bakteriële siektes te voorkom en te behandel. Probiotika wat in akwatiese omgewings toegedien word kan gedefinieer word as a lewende mikrobiese aanvulling wat ‘n positiewe effek op die gasheer het, deur die mikrobiese gemeenskappe geassosieer met die gasheer en die ommidellike omgewing te verander. Hierdie mikrobiese aanvulling verbeter die gesondheid van die visse deur verskeie meganismes wat insluit kompetisie met patogene, produksie van voordelige chemiese verbindings, verhoging van die gasheer se immuniteit en antivirale effekte. Die doel van hierdie studie was om potensiële probiotika te isoleer uit die spysverterings kanaal (SVK) van die Suid Afrikaanse perlemoen spesie, Haliotis midae. Tydens die studie is daar nege verskillende bakteriële spesies geïsoleer en geidentifiseer as stamme verteenwoordegend van Corynebacterium variabilei, Staphylococcus carnosus, Staphylococcus equorum, Staphylococcus cohniii, Vibrio aestuarianus, Vibrio nigripulchritudo, Vibrio cyclitrophicus, Photobacterium leiognathi en Paracoccus marcusii (Hoofstuk 2). Een van die isolate, P. marcusii, het belowende probiotika en potensiële pigmentering eienskappe getoon a.g.v. die produksie van die karotenoïed astazantien. Akwatiese diere is nie daartoe instaat om hierdie pigment te produseer nie en onder akwakultuur toestande kom die visse ook nie in kontak met natuurlike bronne van hierdie pigment nie. Dit lei daartoe dat die vleis van visspesies soos forel en salm grys word wat dit onaantreklik vir verbruikers maak. Daarom word astazantien bygevoeg by visvoer om sodoende ‘n pienk/oranje kleur te verseker.Daar benewens speel astazantien ook ‘n rol in belangrike biologiese funksies van visse. Dit sluit in die verhoging in beskerming teen oksidatiewe stres, bevordering van seksuele volwassenheid, embrio ontwikkeling en eier oorlewing. Twee belangrike akwakultuur spesies in Suid Afrika, Mosambiek tilapia (Oreochromis mossambicus) en reënboog forel (Oncorhynchus mykiss), was in hierdie studie gebruik. Die probiotiese en pigmentasie effek van P. marcusii op reënboog forel was gëevalueer terwyl slegs die probiotiese effek op tilapia geëvalueer weens die onvermoeë van tilapia om die pigment in hul vleis te inkorpereer. Visvoer korrels was omhul met gevriesdroogde bakteriële selle (107 CFU/kg kos) en vir die visse gevoer. Daar was ‘n duidelike verbetering in groei en immuun parameters van tilapia. Visse toegedien met P. marcusii het ‘n hoër persentasie vermeerdering in liggaamsgewig en ‘n beter voedsel omsettings verhouding gehad tydens die verloop van die proef in vergelyking met die kontroles (Hoofstuk 3). In kontras hiermee kon daar geen probiotiese of pigmenterings effekte waargeneem word by die reënboog forel nie. ‘n Moontlike rede hiervoor kon wees dat die konsentrasie van P. marcusii wat by die kos gevoeg is te laag was. Dit is egter ook moontlik dat die astazantien vernietig was voordat dit deur die forel opgeneem is aangesien astazantien ‘n baie onstabiele molekuul is. Verder het ons die impak van verskillende visvoer behandelings op die mikrobiese gemeenskappe in die spysverteringskanaal (SVK) van forel tydens die verloop van die proef bestudeer. Geen ooreenkomste in mikrobiese gemeenskap strukture in die forel SVK is waargeneem tussen die verskillende voer behandelings nie, maar daar is wel ooreenkomste gevind tussen die mikrobiese gemeenskappe van visse by spesifieke tyd intervalle (Hoofstuk 4).
25
Nzakizwanayo, Jonathan. „Investigation of host-microbe interactions in the probiotic bacteria Escherichia coli Nissle 1917“. Thesis, University of Brighton, 2014. https://research.brighton.ac.uk/en/studentTheses/feb9d228-0d2d-4710-9ce6-3abfcb5a3f1f.
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Probiotics are generally live preparations of bacteria that exert beneficial effects on host health when ingested in sufficient quantities. The novel probiotic Escherichia coli strain Nissle 1917 (EcN) has been shown to have a number of beneficial effects in this context, including protection against food-borne pathogens and infectious diarrheal diseases, and maintaining remission of inflammatory bowel diseases by virtue of its anti-inflammatory properties. However, little is known regarding the mechanisms underlying the beneficial effects of this organism. The overall aim of this work was to provide a greater understanding of the mechanisms through which EcN interacts with the mammalian gastro-intestinal epithelium to benefit human health.
26
Eratte, Divya. „Co-encapsulation of Omega-3 fatty acids and probiotic bacteria through complex coacervation“. Thesis, Federation University Australia, 2016. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/156001.
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The research described in this thesis investigated the microencapsulation of omega-3 oil and probiotic bacteria together in a protein-polysaccharide complex coacervate matrix. The synergistic or competitive interactions between the probiotic bacteria and omega-3 fatty acids when packaged in a single microcapsule was determined including how best to utilise such interaction to achieve improved oxidative stability of omega-3 fatty acid and better survival of the probiotic bacteria. Encapsulation and co-encapsulation of tuna oil (O) and Lactobacillus casei 431 (P) as models of omega-3 and probiotic bacteria, respectively, were carried out and the works is described in this thesis in five distinct sections. (1) The optimisation of the complex coacervation process between whey protein isolate (WPI) and gum Arabic (GA). (2) Microencapsulation of tuna oil (O) in WPI-GA complex coacervates followed by spray and freeze drying to produce microcapsules (WPI-O-GA). (3) Microencapsulation of probiotic bacteria L. casei 431 (P) in WPI-GA complex coacervates followed by spray and freeze drying to produce microcapsules (WPI-P-GA). (4) Co-encapsulation of omega-3 oil and L. casei 431 together in WPI-GA coacervate matrix followed by spray and freeze drying to produce co-microcapsules (WPI-P-O-GA). (5) In-vitro digestion evaluation of co-microcapsules and microcapsules to indicate bioavailability. The viability of L. casei was significantly higher in WPI-P-O-GA co-microcapsules than in WPI-P-GA microcapsules in both spray and freeze dried microcapsules. The oxidative stability of tuna oil was significantly higher in spray dried co-capsules. Also, co-microencapsulation increased the survivability of L. casei during simulated digestion. There was no significant influence observed on the release properties of omega-3 oil due to co-microencapsulation. However, the total omega-3 fatty acids in the released oil during in-vitro digestion were found to be higher, when co-microencapsulated. Hence, co-microencapsulation was shown to protect the L. casei and deliver both viable cells and omega-3 oil to human intestine without any significant adverse effect on their functionality and properties.Doctor of Philosophy
27
Boyiri, Blaise B. „Probiotic Potential of Bacterial Isolates From ‘Amabere amaruranu’ Cultured Milk“. Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etd/2389.
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Probiotics are viable nonpathogenic microbes that positively affect host health. Probiotics inhibit infection, activate immunity, and promote mucosal-barrier development. Many microbes have probiotic activity. Nonetheless, the selection of stable strains and their specific mechanism(s) of action are not fully elucidated. Bacteria from ‘Amabere amaruranu’ cultured milk from Kenya were isolated and identified by PCR sequence analysis of the 16S rRNA gene. Isolates were examined for stability to acid and bile, antimicrobial activity, mucin production, and degradation and sensitivity to antibiotics, hence their potential for probiotics. Lactobacillus isolates were acid unstable, bile-stable, nonmucinolytic, and presented antibacterial activity. L. rhamnosus cell fractions increased MUC4 and MUC3 expression in colon cells. Bacillus isolates were acid and bile stable, nonmucinolytic and lacked antimicrobial activity. In conclusion, Lactobacillus isolates that were nonmucinolytic, stable in bile, demonstrated antibacterial activity, sensitive to antibiotics, and stimulated increase MUC4 and MUC3 levels in colon cells could be potential probiotics.
28
Kose, Iskin. „Survival Of Probiotic Microorganisms During Storage After Marketing“. Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613671/index.pdf.
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Probiotics are viable microorganisms that show beneficial effects on the health of the host by improving their intestinal microflora. The microorganisms applied as probiotics mainly include Lactobacillus and Bifidobacterium species. Probiotics can inhibit the bacterial pathogens, reduce serum cholesterol levels, improve lactose tolerance and stimulate the immune response. They also have other properties such astolerance to acid and bile salts, adherence to gastrointestinal cells for colonization, resistance to antibiotics and &beta
-galactosidase acitivity. The properties of probiotic products are determined by the characteristics of the microorganisms they contain. For that reason, isolation and characterization of new strains having probiotic properties is an important issue. New strains are generally isolated from their natural habitats which are fermented dairy products such as kefir. In order to exert beneficial health affects in the digestive system, commercial probiotic products should contain adequate numbers of viable cells. Probiotic microorganisms should protect their viability during their shelf storage. Therefore, the viability of probiotics is especially important for food manufacturers that search for new probiotic strains with good survival and stability properties upon storage. In this study, probiotic microorganisms were isolated from traditional kefir grains known as a &lsquo
complex probiotic&rsquo
. The isolates were firstly identified using biochemical tests, then the putative species belonging to &lsquo
Lactobacillus acidophilus group&rsquo
were identified with 16S rRNA gene sequencing. Analysis of sequencing resulted in differentiation of &ldquo
L. acidophilus group&rdquo
organisms, namely L. amylovorus and L. acidophilus. Moreover, typing of commercial and traditional L. acidophilus strains and L. amylovorus strains were performed with RAPD-PCR by using primer M13. While several L. acidophilus strains showed different RAPD fingerprints most of the L. acidophilus and L. amylovorus strains could not be differentiated due to high similarity of their RAPD fingerprints. Following identification, survival of these isolates in probiotic yogurt preparations were investigated and compared to the survival of commercial probiotics. Consequently, although the survival of kefir grain isolates were less than commercial probiotics, they sustained the minimum recommended level for probiotics (106 cfu/ml) during cold storage. Such level of survival makes them considerably good candidates to be used as commercial probiotic cultures.
29
Wu, Xi-Yang. „Studies on the impact of probiotic bacteria on enteric microbial diversity and immune response“. Access electronically, 2006. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20061205.102712/index.html.
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Hoang, Phuong Ha, Thi Ngoc Mai Cung, Thi Minh Nguyen, Thi Lien Do, Lan Phuong Do und Thi Nhi Cong Le. „Isolation and selection of probiotic bacteria capable of forming biofilm for fermenting soybean meal“. Technische Universität Dresden, 2018. https://tud.qucosa.de/id/qucosa%3A32723.
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Soybean meal (SBM) is residua product after oil extraction, the SBM with 48% protein is used for poultry, cattle. The SBM contains significant amount of anti-nutritional factors. Degradation of most antigenic proteins and protease inhibitors in SBM fermented by fungal, yeast and bacterial strains. Soybean fermented products are used as feed for livestock or aquaculture. Recently, biofilm forming microorganisms were broadly applied for fermentation process using substrates such as rice bran, corn, soybean meal ... to produce probiotics. In this study, we isolated and selected beneficial microbial strains that are capable of well biofilm forming, produce digestive enzymes and resist pathogenic microorganisms to ferment of soybean meal. The result showed that, four microorganism strains including NA5.3; TB2.1; TB4.3 TB4.4 had ability of forming higher biofilm, producing digestive enzymes such as amylase, protease and cellulose. Among them, NA5.3
and TB 4.4 strains had anti-pathogenic bacteria capacity such as Vibrio parahaemolyticus; Enterococcus faecalis; Bacillus cereus and Escherichia coli. Four selected strains were checked effection of pH, temperature, NaCl and bile salt concentration to their biofilm formation. The result indicated suitable conditions for forming biofilm at pH 6-8 range; temperature range 30-37°C; NaCl concentration of 0-3%, bile salt concentration of 0.5-2%. The selected strains grew well during solid
fermentation process, achieved 1011 CFU/gram.Khô đậu nành là sản phẩm còn lại từ quá trình ép dầu chứa tới 48% protein thô và thường được sử dụng làm thức ăn cho gia cầm, gia súc. Nhưng trong khô đậu nành còn chứa một lượng đáng kể một số chất ức chế dinh dưỡng, các chất ức chế này lại được phân hủy bởi quá trình lên men nhờ một số loài vi khuẩn, nấm mốc hay nấm men. Sản phẩm lên men khô đậu tương được sử dụng làm thức ăn cho gia cầm, gia súc hay nuôi trồng thủy sản. Trong những năm gần đây, các vi sinh vật tạo màng sinh học đã được ứng dụng để lên men các cơ chất như cám gạo, ngô, khô đậu nành… tạo sản phẩm probiotics. Trong nghiên cứu này, chúng tôi đã phân lập và tuyển chọn một số vi sinh vật có lợi tạo màng sinh học cao, sinh các enzyme tiêu hóa và kháng lại một số vi khuẩn gây bệnh cho mục đích lên men khô đậu nành. Kết quả đã lựa chọn được 4 chủng vi khuẩn NA5.3; TB2.1; TB4.3 TB4.4 có khả năng tạo màng sinh học cao, sinh các enzyme như amylase, protease và cellulose.Trong đó,hai chủng NA5.3 và TB4.4 có khả năng kháng lại một số vi khuẩn gây bệnh như Vibrio parahaemolyticus; Enterococcus faecalis; Bacillus cereus và Escherichia coli. Bốn chủng vi khuẩn lựa chọn được nghiên cứu ảnh hưởng của các điều kiện lên khả năng tạo màng sinh học của chúng, chúng thích hợp ở pH 6-8; nhiệt độ 30-37°C; NaCl 0-3%, muối mật 0,5-2%. Sử dụng các chủng vi khuẩn này cho quá trình lên men rắn khô đậu tương, mật độ vi khuẩn sau khi lên men đạt 1011 CFU/gram.
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Jawad, Emad. „Technological benefits and potential of incorporation of probiotic bacteria and inulin in soft cheese“. Thesis, University of Plymouth, 2016. http://hdl.handle.net/10026.1/4377.
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There is an increasing consumer demand for dairy products which are safe and free from additives. Microbial starter strains, in combination with other factors, were studied for their contribution to the control of unwanted microbes, and maintaining the quality of soft cheese. The technological and functional characteristics of the starter culture strains Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris, and probiotic bacterial strains Bifidobacterium animalis subsp. lactis BB12, Lactobacillus acidophilus LA-5 and Lactobacillus casei Shirota were investigated. The tests included the milk fermentation, resistance to salt and heat, bile and acid resistance, and growth at a range of temperatures. The probiotic strains differed in their resistance to salt, bile salts and acid. Inhibitory interactions between probiotic bacterial strains with each other and with starter culture strains were not detected. The probiotic bacteria and starter culture strains used have an ability to grow together on homofermentative and heterofermentative differential agar and fermentation of fructose in different levels. Non-starter cheese (NSC), cheese with starter strains (SCS), and cheese with starter and probiotic strains (PSC) were manufactured. The levels of mesophilic aerobic and lactic acid bacteria, moulds and yeasts, and Enterobacteriaceae were evaluated in all cheeses. Their contents of fat, total solids, salt and pH value were tested during 21 days of storage at 2-5°C. Starter culture strains contributed to maintaining the quality of all cheeses, through decreasing the viable count of some undesirable microbes. Cheeses differed in the intensity of the crumbliness attribute, and in preference and intensity of colour attribute. The colour of starter soft cheese, which was tested using a colorimeter, was closer to the colour of probiotic soft cheese than those cheeses which were manufactured without starter culture. The microbial status, storage conditions, rancidity, and the sensory characteristics of unripened soft cheese, which was manufactured with starter culture strains only, were determined during the storage for 50 days at 2-5°C, as well as during their shelf life for the product. Modified Atmosphere Packaging (MAP) contributed to slowing the growth of unwanted microbes, and decreased the values of TBA, TVB-N and TMA in soft cheese. Consequently, delaying the undesirable changes and maintaining the quality of the product and extending its shelf life, when compared with vacuum, brine, and air packaging methods, under the same storage conditions. Potential effects of inulin on the cheese quality and sensory characteristics of probiotic soft cheese were investigated. The cheeses differed in their loads of lactic acid bacteria, in addition to the total solids and water activity. The levels of probiotic bacterial strains were higher in probiotic soft cheese that manufactured with inulin than in cheese without inulin, with a potential in the formation synbiotic between the probiotic strains LA-5 and BB12 and inulin. Both cheeses were recorded to have high acceptance in the cheese attributes, in terms of appearance, aroma, colour texture and the overall acceptance. The presence of inulin increased the hardness of cheese under vacuum packaging, after storage for 14 days at 2-5°C.
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Krahulcová, Aneta. „Vývoj probiotického doplňku stravy“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2011. http://www.nusl.cz/ntk/nusl-216800.
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The thesis deals with a theme of probiotic mikroorganisms which are aplicated as a dietary supplement. Health benefit on the host have been known for a long time, however, there might be some negative effects affecting a consumer. In connection with this observation defining requirements and evaluating of safety of probiotics in food was necessary. The new probiotic dietary supplement can not be expanded on the market without these processes. Every strain must be tested separately on each property. The ability of rezistance against conditions inside human gastrointestinal tract belongs to the most basic tests. The aim of the practical part is testing this ability of rezistance in vitro by simulated conditions. The model of gastrointestinal juices was designed according to the Czechoslovak codex. The form contributes to the higher rezistance of probiotics within implementing to the host. Also a dosage form of probiotics was involved to a in vitro testing.
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Fayemi, Emmanuel. „Inhibition of non-O157 Shiga toxin Escherichia coli in African fermented foods by probiotic bacteria“. Thesis, University of Pretoria, 2015. http://hdl.handle.net/2263/53493.
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Non-O157 Shiga toxin producing Escherichia coli (STEC) serotypes are increasingly being associated with outbreaks of foodborne infections and illness. This study evaluated the in vitro probiotic characteristics of Lactobacillus plantarum strain B411 and dominant lactic acid bacteria (LAB) isolated from traditional African fermented maize gruel (ogi). Subsequently, the effects of acid adaption and those potential probiotic bacteria on the growth and survival of non-O157 STEC strains in fermented goat s milk and traditional African fermented cereal-based foods were investigated.
Two of the 14 lactic acid bacteria (LAB) strains that were isolated from ogi together with L. plantarum strain B411 possess hydrophobic cell surface with ability to coaggregate with pathogens as well as antimicrobial activities against non-O157 STEC strains and E. coli ATCC 25922. The three strains with in vitro probiotic attributes also exhibited high level of adhesion to Caco-2 cells and the two LAB strains from ogi spontaneous fermentation were genetically similar to other reported potential probiotic bacteria.
Though prior adaptation to acid enhanced acid tolerance of non-O157 STEC strains in Brain Heart Infusion (BHI) broth at low pH, it was detrimental to the survival in fermented goat s milk. The growth of both acid adapted (AA) and non-acid adapted (NAA) non-O157 STEC strains was not inhibited by the single strain potential probiotic L. plantarum B411 in fermented goat s milk. However, combination of yoghurt starter culture and potential probiotic L. plantarum B411 for the fermentation of the goat s milk had a bacteriostatic effect on the NAA non-O157 STEC strains while the growth of AA non-O157 STEC strains were substantially inhibited.
Non-O157 Shiga toxin producing Escherichia coli (STEC) serotypes are increasingly being associated with outbreaks of foodborne infections and illness. This study evaluated the in vitro probiotic characteristics of Lactobacillus plantarum strain B411 and dominant lactic acid bacteria (LAB) isolated from traditional African fermented maize gruel (ogi). Subsequently, the effects of acid adaption and those potential probiotic bacteria on the growth and survival of non-O157 STEC strains in fermented goat s milk and traditional African fermented cereal-based foods were investigated.
Two of the 14 lactic acid bacteria (LAB) strains that were isolated from ogi together with L. plantarum strain B411 possess hydrophobic cell surface with ability to coaggregate with pathogens as well as antimicrobial activities against non-O157 STEC strains and E. coli ATCC 25922. The three strains with in vitro probiotic attributes also exhibited high level of adhesion to Caco-2 cells and the two LAB strains from ogi spontaneous fermentation were genetically similar to other reported potential probiotic bacteria.
Though prior adaptation to acid enhanced acid tolerance of non-O157 STEC strains in Brain Heart Infusion (BHI) broth at low pH, it was detrimental to the survival in fermented goat s milk. The growth of both acid adapted (AA) and non-acid adapted (NAA) non-O157 STEC strains was not inhibited by the single strain potential probiotic L. plantarum B411 in fermented goat s milk. However, combination of yoghurt starter culture and potential probiotic L. plantarum B411 for the fermentation of the goat s milk had a bacteriostatic effect on the NAA non-O157 STEC strains while the growth of AA non-O157 STEC strains were substantially inhibited.
Non-O157 Shiga toxin producing Escherichia coli (STEC) serotypes are increasingly being associated with outbreaks of foodborne infections and illness. This study evaluated the in vitro probiotic characteristics of Lactobacillus plantarum strain B411 and dominant lactic acid bacteria (LAB) isolated from traditional African fermented maize gruel (ogi). Subsequently, the effects of acid adaption and those potential probiotic bacteria on the growth and survival of non-O157 STEC strains in fermented goat s milk and traditional African fermented cereal-based foods were investigated.
Two of the 14 lactic acid bacteria (LAB) strains that were isolated from ogi together with L. plantarum strain B411 possess hydrophobic cell surface with ability to coaggregate with pathogens as well as antimicrobial activities against non-O157 STEC strains and E. coli ATCC 25922. The three strains with in vitro probiotic attributes also exhibited high level of adhesion to Caco-2 cells and the two LAB strains from ogi spontaneous fermentation were genetically similar to other reported potential probiotic bacteria.
Though prior adaptation to acid enhanced acid tolerance of non-O157 STEC strains in Brain Heart Infusion (BHI) broth at low pH, it was detrimental to the survival in fermented goat s milk. The growth of both acid adapted (AA) and non-acid adapted (NAA) non-O157 STEC strains was not inhibited by the single strain potential probiotic L. plantarum B411 in fermented goat s milk. However, combination of yoghurt starter culture and potential probiotic L. plantarum B411 for the fermentation of the goat s milk had a bacteriostatic effect on the NAA non-O157 STEC strains while the growth of AA non-O157 STEC strains were substantially inhibited.
Non-O157 Shiga toxin producing Escherichia coli (STEC) serotypes are increasingly being associated with outbreaks of foodborne infections and illness. This study evaluated the in vitro probiotic characteristics of Lactobacillus plantarum strain B411 and dominant lactic acid bacteria (LAB) isolated from traditional African fermented maize gruel (ogi). Subsequently, the effects of acid adaption and those potential probiotic bacteria on the growth and survival of non-O157 STEC strains in fermented goat s milk and traditional African fermented cereal-based foods were investigated.
Two of the 14 lactic acid bacteria (LAB) strains that were isolated from ogi together with L. plantarum strain B411 possess hydrophobic cell surface with ability to coaggregate with pathogens as well as antimicrobial activities against non-O157 STEC strains and E. coli ATCC 25922. The three strains with in vitro probiotic attributes also exhibited high level of adhesion to Caco-2 cells and the two LAB strains from ogi spontaneous fermentation were genetically similar to other reported potential probiotic bacteria.
Though prior adaptation to acid enhanced acid tolerance of non-O157 STEC strains in Brain Heart Infusion (BHI) broth at low pH, it was detrimental to the survival in fermented goat s milk. The growth of both acid adapted (AA) and non-acid adapted (NAA) non-O157 STEC strains was not inhibited by the single strain potential probiotic L. plantarum B411 in fermented goat s milk. However, combination of yoghurt starter culture and potential probiotic L. plantarum B411 for the fermentation of the goat s milk had a bacteriostatic effect on the NAA non-O157 STEC strains while the growth of AA non-O157 STEC strains were substantially inhibited.
Non-O157 Shiga toxin producing Escherichia coli (STEC) serotypes are increasingly being associated with outbreaks of foodborne infections and illness. This study evaluated the in vitro probiotic characteristics of Lactobacillus plantarum strain B411 and dominant lactic acid bacteria (LAB) isolated from traditional African fermented maize gruel (ogi). Subsequently, the effects of acid adaption and those potential probiotic bacteria on the growth and survival of non-O157 STEC strains in fermented goat s milk and traditional African fermented cereal-based foods were investigated.
Two of the 14 lactic acid bacteria (LAB) strains that were isolated from ogi together with L. plantarum strain B411 possess hydrophobic cell surface with ability to coaggregate with pathogens as well as antimicrobial activities against non-O157 STEC strains and E. coli ATCC 25922. The three strains with in vitro probiotic attributes also exhibited high level of adhesion to Caco-2 cells and the two LAB strains from ogi spontaneous fermentation were genetically similar to other reported potential probiotic bacteria.
Though prior adaptation to acid enhanced acid tolerance of non-O157 STEC strains in Brain Heart Infusion (BHI) broth at low pH, it was detrimental to the survival in fermented goat s milk. The growth of both acid adapted (AA) and non-acid adapted (NAA) non-O157 STEC strains was not inhibited by the single strain potential probiotic L. plantarum B411 in fermented goat s milk. However, combination of yoghurt starter culture and potential probiotic L. plantarum B411 for the fermentation of the goat s milk had a bacteriostatic effect on the NAA non-O157 STEC strains while the growth of AA non-O157 STEC strains were substantially inhibited.Thesis (PhD)--University of Pretoria, 2015.
Food Science
PhD
Unrestricted
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Makete, Goitsemang. „Isolation identification and screening of potential probiotic bacteria in milk from South African Saanen goats“. Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/53515.
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In order to meet the increasing demand for food quality and safety, the control of pathogenic microorganisms from farms to consumers remains a continuous challenge. Disease has always been a critical issue in animal production, affecting animal health and wellbeing. For several decades, antibiotics and chemotherapeutic agents have been used in animal feed to treat and prevent infectious diseases or to promote growth. However, there are concerns about the risk of development of cross-resistance and multiple antibiotic resistance in pathogenic bacteria in both human and livestock. To slow the development of resistance, some countries have restricted or banned use of antibiotics in feeds. Therefore, the need to find alternatives to growth-promoting and prophylactic uses of antibiotics is of outmost importance in agriculture. Beneficial bacteria, mainly lactic acid bacteria have been effectively used previously as feed additives in livestock to manipulate the gut microbiota in order to support animal health.
Therefore, the current study focused on isolation and characterisation of probiotic bacteria from raw goats milk. The first part of the study aimed at isolating and identifying potential probiotic bacteria. Bacteria from raw milk were cultured onto selective media including, M17 agar and MRS agar supplemented with 0.05 g/L cysteine-hydrochloride. A total of seventeen lactic acid bacteria were isolated, and were then identified using phenotypic assays, 16S rDNA gene sequencing and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF). Lactobacillus plantarum strains (KJ026587.1, KM207826.1, KC83663.1, and KJ958428.1) and Pediococcus acidalactici were obtained. Potential probiotic bacteria were identified based on their ability to survive in the gastrointestinal conditions that include growth at low pH and bile tolerance, production of antimicrobial compounds and adhesion to the intestinal mucosa. The second part of the study focused on in vitro screening of probiotic attributes in the isolates. Production of antimicrobial activity, ability to adhere to intestinal cells and survive in the gastrointestinal tract, as well as antibiotic susceptibility, were among the main probiotic properties that were analysed to assess functionality and safety of the isolates.
The in vitro studies revealed that the five isolates were tolerant to acidic pH and high concentrations of bile salts, which are characteristics necessary for the probiotics to survive in the gastrointestinal tract. These isolates were also found to exhibit antimicrobial activity against some of the pathogens affecting the goats industry. The five selected LAB strains displayed resistance to vancomycin, gentamycin and nalidixic acid, but were susceptible to a broad range of other antibiotics. However, the antibiotics to which the isolates were resistant might not pose problems as it is unlikely to be transmissible between bacteria cells. Fluorescent microscopy analysis, revealed strong adhesion of the isolates to the ileum mucus following their staining with BacLight viability probe.
This study is the first in South Africa that isolated and characterised probiotic bacteria from raw goats milk. Most studies on application of probiotics in ruminants have been performed in cows and calves, and there is very little information for lambs and goats. The results of this study suggest that the five selected bacteria could be used as potential candidates for the development of direct fed microbials and growth promoters that can be used in improving the overall health status of the goats. Formulation of the best cocktail and its use as direct fed microbials for goats will result in improved nutrition and productivity.Dissertation (MSc)--University of Pretoria, 2015.
Microbiology and Plant Pathology
MSc
Unrestricted
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Vajglová, Klára. „Vliv různých potravin na viabilitu a růst probiotických bakterií“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-295711.
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The goal of this work was a study the influence of food and beverages on the viability and growth of probiotic bacteria. The influence of food and beverages was tested on monocultures of Lactobacillus acidophilus, Bifidobacterium breve and mixed culture of probiotic microorganisms. In the experimental part, probiotic cultures were incubated in selected foods and beverages. After that they were tested in a model conditions of digestive tract. In some probiotic cultures, growth of viable cells during incubation in the digestive tract was observed. The increase of probiotic cells was showed predominantly in foods that contained higher levels of sugars and fats or a suitable combination. Their increase was up to four times in some cases. Based on the results, mixed probiotic cultures aren’t surprisingly exhibited better survival and maintain sufficient amount of viable cells even during the digestive process. Moreover, probiotic microorganisms could be recommended to consumption during meals better than just with a beverage.
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Barnhart, Katelyn L. „The Influence of Probiotic Supplements on Microbial Diversity in the Gastrointestinal Microbiome of Healthy Horses“. The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437693649.
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Oliverio, Alexandria Elizabeth. „The Effect of Glyphosate on Human Gastrointestinal Bacteria Lactobacillus, Streptococcus thermophilus, and Bifidobacterium Obtained from Probiotic Medical Food“. Ohio Dominican University Honors Theses / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=oduhonors1620219658669347.
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Talwalkar, Akshat, University of Western Sydney, of Science Technology and Environment College und of Science Food and Horticulture School. „Studies on the oxygen toxicity of probiotic bacteria with reference to Lactobacillus acidophilus and Bifidobacterium spp“. THESIS_CSTE_SFH_Talwalkar_A.xml, 2003. http://handle.uws.edu.au:8081/1959.7/629.
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Oxygen toxicity is considered significant in the poor survival of probiotic bacteria such as Lactobacillus acidophilus and Bifidobacterium spp. in yoghurts. This study investigated methods to protect these bacteria from oxygen exposure. To confirm the accuracy of the reported survival estimates of L. acidophilus or Bifidobacterium spp. in yoghurts, the reliability of several enumeration media was evaluated with different commercial yoghurts. None of the media however, was found reliable thereby casting doubts on the reported cell numbers of probiotic bacteria in yoghurts. After much research,it was found that although oxygen can be detrimental to L. acidophilus and Bifidobacterium spp.in culture broths, it may not be significant for their poor survival in yoghurts. Nevertheless, techniques such as oxidative stress stress adaption, alternative packaging materials and microencapsulation as investigated in this study, can serve as general protective techniques to help yoghurt manufacturers in maintaining the recommended numbers of probiotic bacteria in their products. This would eventually assist in the efficient delivery of probiotic health benefits to yoghurt consumers.Doctor of Philosphy (PhD)
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Martoni, Christopher. „Microencapsulated bile salt hydrolyzing probiotic lactic acid bacteria for use in hypercholesterolemia and associated cardiovascular diseases“. Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66810.
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Elevated serum cholesterol, particularly in the low-density lipoprotein (LDL) fraction, is a major independent risk factor for atherosclerosis and coronary artery disease. Current evidence from a variety of human and animal trials suggests a cholesterol lowering effect of specific strains of probiotic lactic acid bacteria; however the results are frequently inconclusive and supportive mechanistic data is scarce. A need therefore exists for low-cost and effective new technologies to meet the present demands and future challenges of probiotics for use in hypercholesterolemia. In this thesis, microcapsule formulations for the entrapment of genetically engineered and non-genetically engineered lactic acid bacteria with elevated bile salt hydrolase activity were designed and developed. Strain specific microencapsulation techniques were used to produce spherical microcapsules with narrow size distribution and high cell loading. By enhancing the micro-environment of the encased strains, a high number of viable cells were delivered to the intestine with protection from acid, bile and mechanical stresses. Furthermore, enzymatic activity towards conjugated bile salt substrates was maintained, with significant preference for glyco-conjugates, when administered through a dynamic model simulating human gastrointestinal (GI) transit. The Bio F1B golden Syrian hamster was selected, after species and diet based studies, as a model of hyperlipidemia and cholesterol and bile acid metabolism. Using this model, orally delivered microencapsulated genetically engineered L. plantarum 80 strain significantly lowered total and LDL cholesterol, and improved the atherogenic profile associated with hypercholesterolemia. The effectiveness of the formulation was shown to be dependent on dose and frequency of administration. Furthermore, heart histological samples confirmed a protective effect. Microencapsulated bile salt hydrolase acUn taux de cholestérol élevé, en particulier dans les lipoprotéines de faible densité (LDL), est un facteur de risque important pour l'athérosclérose et la maladie coronarienne. La recherche chez les humains et les animaux indique que des souches spécifiques de bactéries lactiques probiotiques peuvent réduire le taux de cholestérol; cependant les résultats sont fréquemment peu concluants et les données mécanistiques sont rares. Un besoin existe donc pour de nouvelles technologies peu coûteuses et efficaces pour répondre aux demandes présentes et futures de traitement probiotique pour l'hypercholestérolémie. Dans cette thèse, je présente la conception et le développement des formulations pour la micro-encapsulation des bactéries génétiquement et non-génétiquement modifiées qui produisent une hydrolase de sel biliaire. Des techniques spécifiques de micro-encapsulation ont été employées pour produire des microcapsules sphériques, de dimension régulière et avec une concentration élevée de cellules. Les microcapsules permettent l'administration d'un grand nombre de bactéries viable jusqu'à l'intestin en les protégeant contre l'acide gastrique, la bile et les dommages mécaniques. De plus, l'utilisation d'un modèle dynamique de passage gastrointestinal démontre que l'activité enzymatique contre les sels biliaires conjugués est maintenue, avec une préférence significative pour les glyco-conjugués. Le hamster Syrien bio F1B a été sélectionné comme modèle de l'hyperlipidémie et pour le métabolisme du cholestérol et des acides biliaires. Utilisant ce modèle, la souche génétiquement modifiée L. plantarum 80 micro-encapsulée a réduit le taux de cholestérol total et cholestérol LDL, et a amélioré le profil athérogenique associé à l'hypercholestérolémie. L'efficacité de la formulation était dépendante de la dose et de la fréquence. De plus,$
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Botha, Marlie. „Selection of probiotic lactic acid bacteria for horses based on in vitro and in vivo studies“. Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17846.
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Thesis (MSc)--Stellenbosch University, 2011.ENGLISH ABSTRACT: The equine gastro-intestinal tract (GIT) is a relatively unexplored niche concerning the presence of natural microbiota. Studies have shown that disruption of the microbial population naturally present in the GIT leads to the onset of several forms of gastro-intestinal disorders. To maintain a balanced microbiota, probiotic bacteria need to be administered at specific levels. Beneficial microorganisms assist with digestion of the feed, absorption of nutrients from the GIT, strengthens the immune system and improves the animal‟s growth. Various combinations of lactic acid bacteria (LAB) have been administered to horses, but have failed to benefit the host in any of the latter criteria. The screening for alternative strains with probiotic properties is thus necessary. Two strains (Lactobacillus equigenerosi Le1 and Lactobacillus reuteri Lr1) were originally isolated from horse faeces. Lactobacillus plantarum 423 and Enterococcus mundtii ST4SA, both bacteriocin-producing strains, were isolated from sorghum beer and soy beans, respectively. All four strains survived growth at acidic conditions (pH 3) and the presence of 0.5%, 1.0% and 1.5% (w/v) bile salts. L. reuteri Lr1 was the most resistant to these conditions. All strains adhered to buccal (cheek) epithelium cells sampled from horses. L. equigenerosi Le1 and E. mundtii ST4SA, however, invaded the cells, but without visible signs of disrupting the cells. None of the strains contained genes encoding adhesion to collagen (Ace), resistance to vancomycin A, B and C, or, production of aggregation substance (AS), cytolysin (Cyl) and, non-cytolysin (β hemolysin III), suggesting that they are non-virulent. Of all strains, L. equigenerosi Le1 competed the best with Clostridium sp. C6 for adherence to epithelial cells. L. equigenerosi Le1 and L. reuteri Lr1, showed the highest level of co-aggregation with Clostridium sp. C6. When the four strains were administered to horses over a period of 10 days, L. reuteri Lr1 was retained the longest (8 days) in the GIT. The numbers of viable cells of Clostridium spp. and Salmonella spp. remained constant during administration of the four strains. Blood analyses showed no negative effects from administering the strains. Total white blood cell counts remained unchanged. However, a small but tentative increase in neutrophil and eosinophil cell numbers has been recorded, suggesting that the LAB may have elicited a mild, transient, intolerance reaction. The glucose, lactate and urea levels decreased during administration with the four LAB strains.
AFRIKAANSE OPSOMMING: Die spysverteringstelsel (SVS) van die perd is 'n relatief onbekende nis wat die voorkoms van natuurlike mikrobiota betref. Studies het getoon dat versteuring van die natuurlike mikrobiese populasie in die SVS aanleiding kan gee tot die ontwikkeling van menige vorms van gastro-intestinale ongesteldhede. Om 'n gebalanseerde mikrobiota te verseker, moet probiotiese bakterieë teen 'n spesifieke vlak toegedien word. Voordelige mikroorganismes bevorder vertering en absorpsie van nutriënte vanaf die SVS, versterk die immuunsisteem en bevorder die groei van die dier. Verskeie kombinasies van melksuurbakterieë is reeds aan perde toegedien, maar sonder ooglopende voordele vir die dier. Die soeke na alternatiewe stamme met probiotiese eienskappe is dus noodsaaklik. Twee melksuurbakterieë (Lactobacillus equigenerosi Le1 en Lactobacillus reuteri Lr1) is oorspronklik uit perdemis geïsoleer. Lactobacillus plantarum 423 en Enterococcus mundtii ST4SA, beide bakteriosienproduserende stamme, is afsonderlik van sorghumbier en sojabone geïsoleer. Al vier spesies groei by lae pH (pH 3) en in die teenwoordigheid van 0.5%, 1.0% en 1.5% (m/v) galsoute. L. reuteri Lr1 is die mees bestand onder hierdie toestande. Al vier stamme het aan wang epiteelselle van perde geheg. L. equigenerosi Le1 en E. mundtii ST4SA het egter die epiteelselle binnegedring, maar sonder opsigtelike vernietiging van die selle. Nie een van die stamme besit gene wat kodeer vir aanhegting aan kollageen (Ace), bestandheid teen vankomisien A, B en C, of produksie van, sel-aggregasie (AS), sitolisien (Cyl) en nie-sitolisien (β-hemolisien III), wat daarop dui dat hulle nie-virulent is. Van al die stamme het L. equigenerosi Le1 die beste met Clostridium sp. C6 vir aanhegting aan epiteelselle gekompeteer. L. equigenerosi Le1 en L. reuteri Lr1, het die beste vlak van ko-aggregasie met Clostridium sp. C6 getoon. Met die toediening van 'n kombinasie van die vier stamme aan die perde oor 'n periode van 10 dae, het L. reuteri Lr1 die langste retensie (8 dae) in die SVS getoon. Die aantal lewende selle van Clostridium spp. en Salmonella spp. het konstant gebly tydens toediening van die vier stamme. Toediening van die vier stamme het geen negatiewe effek getoon met resultate verkry van bloed analises nie. Die totale witbloed seltellings het onveranderd gebly. 'n Klein, maar tentatiewe, toename in neutrofiel- en eosinofiel selgetalle is waargeneem, wat daarop dui dat die melksuurbakterieë 'n geringe allergiese reaksie teweeggebring het. Die glukose, laktaat en ureum vlakke het gedaal tydens die toediening van die vier melksuurbakterie stamme.
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Hussein, Walaa. „Discovery of Novel Lactic Acid Bacteria Strains with Antimicrobial and Probiotic Traits for Beneficial Industrial Applications“. The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595587732038431.
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Talwalkar, Akshat. „Studies on the oxygen toxicity of probiotic bacteria with reference to Lactobacillus acidophilus and Bifidobacterium spp“. Thesis, View thesis, 2003. http://handle.uws.edu.au:8081/1959.7/629.
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Oxygen toxicity is considered significant in the poor survival of probiotic bacteria such as Lactobacillus acidophilus and Bifidobacterium spp. in yoghurts. This study investigated methods to protect these bacteria from oxygen exposure. To confirm the accuracy of the reported survival estimates of L. acidophilus or Bifidobacterium spp. in yoghurts, the reliability of several enumeration media was evaluated with different commercial yoghurts. None of the media however, was found reliable thereby casting doubts on the reported cell numbers of probiotic bacteria in yoghurts. After much research,it was found that although oxygen can be detrimental to L. acidophilus and Bifidobacterium spp.in culture broths, it may not be significant for their poor survival in yoghurts. Nevertheless, techniques such as oxidative stress stress adaption, alternative packaging materials and microencapsulation as investigated in this study, can serve as general protective techniques to help yoghurt manufacturers in maintaining the recommended numbers of probiotic bacteria in their products. This would eventually assist in the efficient delivery of probiotic health benefits to yoghurt consumers.
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Talwalkar, Akshat. „Studies on the oxygen toxicity of probiotic bacteria with reference to Lactobacillus acidophilus and Bifidobacterium spp“. View thesis, 2003. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20040416.103233/index.html.
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Miller, Craig William. „A study of packaging methods to reduce the dissolved oxygen content in probiotic yoghurt“. View thesis, 2003. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20040701.172045/index.html.
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Hinkel, Brandon Jerome. „Microcapsule Containing Lactic Acid Bacteria for Treatment of Peptic Ulcers“. DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/967.
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Probiotics are marketed throughout the world to promote the health of the consumer by improving the microorganisms that normally occur in the intestinal tract (Tannock, 1997). It has also been suggested that probiotics can prevent pathogen infections by adhering to the intestinal mucosa (Lee, Lim, Teng, Ouwehand, Tuomola, & Salminen, 2000). While probiotics can be delivered to the infected areas in multiple fashions, microencapsulation is a newer form of delivering probiotics straight to the infected area. A whey protein microcapsule is thought to protect the probiotics from stomach acid and delivers the treatment to the affected area. To ensure this microencapsulation treatment is affective, the microcapsules will be stained and imaged to see if the microcapsules are constructed in a way which is consistent with the theory: a whey protein microcapsule surrounding bacteria and fat droplets. Through these experiments, it was shown that the microcapsule was not constructed as previously thought. Instead of a thin layer of protein surrounding the bacteria, it more closely resembled a solid ball of protein with bacteria and fat trapped inside. The bacteria are able to survive stomach like conditions (0.1M HCl for 8 hours) due to other forms of microencapsulation.
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Miller, Craig William. „A study of packaging methods to reduce the dissolved oxygen content in probiotic yoghurt“. Thesis, View thesis, 2003. http://handle.uws.edu.au:8081/1959.7/633.
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Probiotic bacteria are added to commercial yoghurts as adjunct cultures, to impart health benefits to consumers. To gain maximum therapeutic benefit, the bacteria must remain viable over the shelf life of the yoghurt. Studies have shown, however, that the viability of these bacteria decreases significantly over this period and in some products, is negligible prior to the expiry date. Some strains of probiotic bacteria are oxygen sensitive. Yoghurt has been found to contain a significant concentration of dissolved oxygen and it has been proposed that this has a negative effect on probiotic viability. In this research, several tests were conducted and observations made. Experiments were conducted with non-commercial probiotic cultures to observe the effect of low oxygen environment on probiotic viability. No significant difference existed in viability between probiotic bacteria stored in oxygen reduced yoghurt and regular yoghurt. All yoghurt stored in oxygen barrier packaging material displayed enhanced shelf-life properties, this was observed in replicated experiments. Oxygen barrier packaging combined with an oxygen scavenging material was found to be the most effective oxygen removal system, particularly when used with set type yoghurt.
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Miller, Craig William, University of Western Sydney, of Science Technology and Environment College und of Science Food and Horticulture School. „A study of packaging methods to reduce the dissolved oxygen content in probiotic yoghurt“. THESIS_CSTE_SFH_Miller_C.xml, 2003. http://handle.uws.edu.au:8081/1959.7/633.
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Probiotic bacteria are added to commercial yoghurts as adjunct cultures, to impart health benefits to consumers. To gain maximum therapeutic benefit, the bacteria must remain viable over the shelf life of the yoghurt. Studies have shown, however, that the viability of these bacteria decreases significantly over this period and in some products, is negligible prior to the expiry date. Some strains of probiotic bacteria are oxygen sensitive. Yoghurt has been found to contain a significant concentration of dissolved oxygen and it has been proposed that this has a negative effect on probiotic viability. In this research, several tests were conducted and observations made. Experiments were conducted with non-commercial probiotic cultures to observe the effect of low oxygen environment on probiotic viability. No significant difference existed in viability between probiotic bacteria stored in oxygen reduced yoghurt and regular yoghurt. All yoghurt stored in oxygen barrier packaging material displayed enhanced shelf-life properties, this was observed in replicated experiments. Oxygen barrier packaging combined with an oxygen scavenging material was found to be the most effective oxygen removal system, particularly when used with set type yoghurt.Doctor of Philosophy (PhD)
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Theunissen, Johnita. „Identification of probiotic microbes from South African products using PCR-based DGGE analyses“. Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/49983.
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Thesis (MScFoodSc)--Stellenbosch University, 2004.ENGLISH ABSTRACT: The regular consumption of probiotics is becoming a recognized trend in the food industry due to several reported health benefits. A probiotic is defined as a live microbial feed supplement that beneficially affects the host animal by improving its intestinal microbial balance. A wide variety of probiotic food products are available on the South African market and comprise an assortment of fermented milks, as well as lyophilized preparations in tablet or capsule form. Strains of Lactobacillus acidophilus and Bifidobacterium species are mostly used as probiotic microbes in the industry due to their health enhancing effect. The survival of sensitive probiotic microbial species in food matrices are influenced by various factors such as oxygen concentration, pH levels and manufacturing and storage conditions. These should be considered and monitored as the South African food and health regulations stipulate that probiotic microbes should be present at a concentration of 10⁶ cfu.ml ̄ ¹' in order to exert a beneficial effect. Some health benefits are also correlated to specific microbial species and strains and these factors have resulted in the need for the rapid and accurate identification of probiotic microbes present in food products. The probiotic microbes present in probiotic yoghurts and supplements have in the past been identified using traditional methods such as growth on selective media, morphological, physiological and biochemical characteristics. However, even some of the most sophisticated cultural-dependant techniques are not always sufficient for the identification and classification of especially Bifidobacterium, as well as closely related Lactobacillus species. Molecular techniques are more often employed for the rapid and accurate detection, identification and characterization of microbial species present in food products. The aim of this study was to detect and identify the probiotic species present in various commercial South African yoghurts and lyophilized preparations using peR-based DGGE analysis. A 200 bp fragment of the V2-V3 region of the 16S rRNA gene was amplified and the peR fragments were resolved by DGGE. The unique fingerprints obtained for each product were compared to two reference markers A and B in order to identify the bands present. The results obtained were verified by species-specific peR, as well as sequence analyses of bands that could not be identified when compared to the reference markers. Only 54.5% of the South African probiotic yoghurts that were tested did contain all the microbial species as were mentioned on the labels of these products, compared to merely one third (33.3%) of the lyophilized probiotic food supplements. Some Bifidobacterium species were incorrectly identified according to some product labels, while other products contained various microbes that were not mentioned on the label. Sequence analysis confirmed the presence of a potential pathogenic Streptococcus species in one of the yoghurt products and in some instances the probiotic species claimed on the labels were non-scientific and misleading. The data obtained in this study showed that the various South African probiotic products tested were of poor quality and did not conform to the South African regulations. peR-based DGGE analysis proofed to be a valuable approach for the rapid and accurate detection and identification of the microbial species present in South African probiotic products. This could help with future implementation of quality control procedures in order to ensure a reliable and safe probiotic product to the consumer.
AFRIKAANSE OPSOMMING: Die gereelde inname van probiotiese produkte is besig om In erkende tendens in die voedselindustrie te word, as gevolg van verskeie gesondheidsvoordele wat daaraan gekoppel word. In Probiotika word gedefinieer as In voedingsaanvulling wat uit lewendige mikrobes bestaan en wat In voordelige effek op mens of dier het deur In optimale mikrobiese balans in die ingewande te handhaaf. In Wye verskeidenheid probiotiese voedselprodukte is tans beskikbaar op die Suid- Afrikaanse mark. Hierdie bestaan hoofsaaklik uit verskeie gefermenteerde melkprodukte asook 'n reeks tablette en kapsules wat probiotiese mikrobes in gevriesdroogde vorm bevat. Lactobacillus acidophilus tipes en Bifidobacterium spesies word die algemeenste in die voedselindustrie gebruik aangesien hierdie spesifieke mikrobes bekend is om goeie gesondheid te bevorder. Die oorlewing van sensitiewe probiotiese mikrobiese spesies in voedsel matrikse word beïnvloed deur faktore soos suurstof konsentrasie, pH-vlakke en vervaardigings- en opbergings kondisies. Hierdie faktore moet in aanmerking geneem word en verkieslik gemonitor word aangesien die Suid-Afrikaanse voedsel en gesondheids regulasies stipuleer dat probiotiese mikrobes teen In konsentrasie van 10⁶ kolonie vormende eenhede per ml teenwoordig moet wees om In voordelige effek te toon. Sommige gesondheidsvoordele word direk gekoppel aan spesifieke mikrobiese spesies en spesie-tipes. Hierdie faktore het gelei tot In groot aanvraag na vinnige en akkurate metodes vir die identifikasie van probioties mikrobes in voedselprodukte. Die probiotiese mikrobes teenwoordig in probiotiese joghurts en ook die gevriesdroogde vorms in tablette en kapsules, was al geïdentifiseer deur gebruik te maak van tradisionele metodes soos groei op selektiewe media, morfologiese, fisiologiese en biochemiese eienskappe. Selfs van die mees gesofistikeerde kultuur-afhanklike tegnieke is egter nie altyd voldoende vir die identifikasie en klassifikasie van veral Bifidobacterium en na-verwante Lactobacillus spesies nie. Molekulêre metodes word dikwels aangewend vir die vinnige en akkurate deteksie, identifikasie en karakterisering van mikrobes teenwoordig in voedselprodukte. Die doel van hierdie studie was om die probiotiese mikrobes teenwoordig in verskeie Suid-Afrikaanse joghurts en gevriesdroogde aanvullings, te identifiseer deur gebruik te maak van polimerase kettingreaksie (PKR)-gebaseerde denaturerende gradiënt jelelektroforese (DGGE) analise. 'n PKR fragment van 200 bp van die V2-V3 gedeelte van die 16S ribosomale RNS (rRNS) geen is geamplifiseer, en die PKR fragmente is geskei met behulp van DGGE. Die unieke vingerafdrukke wat verkry is vir elke produk is teen twee verwysings merkers A en B vegelyk om die bande teenwoordig in die profiele te identifiseer. Die resultate is bevestig deur spesies-spesifieke PKR en ook deur die ketting volgordes van die DNS fragmente te bepaal wat nie geïdentifiseer kon word deur vergelyking met die verwysings merkers nie. Slegs 54.5% van die Suid-Afrikaanse probiotiese joghurts wat getoets is het al die mikrobiese spesies bevat soos aangedui was op die etikette van hierdie produkte, teenoor slegs 'n derde (33.3%) van die gevriesdroogde voedingsaanvullings. Sekere Bifidobacterium spesies is verkeerd geïdentifiseer op sommige van die produk etikette, terwyl ander produkte verskeie mikrobes bevat het wat nie op die etiket aangedui was nie. 'n Potensiële patogeniese Streptococcus spesie is in een van die joghurt produkte gevind soos bevestig deur DNS kettingvolgorde bepalings. In sommige gevalle was die probiotiese spesienaam wat aangedui is op die etiket onwetenskaplik en misleidend. Die resultate wat uit hierdie studie verkry is dui aan dat die Suid-Afrikaanse probiotiese produkte wat getoets is van 'n swak gehalte is en nie aan die Suid- Afrikaanse regulasies voldoen nie. Daar is getoon dat PKR-gebaseerde DGGE analise 'n waardevolle tegniek kan wees vir die akkurate deteksie en identifisering van die mikrobiese spesies teenwoordig in probiotiese produkte. Dit kan help met die toekomstige implementering van kwaliteitskontrolerings prosedures om 'n mikrobiologiese betroubare en veilige produk aan die verbruiker te verseker.
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von, Schillde Marie-Anne [Verfasser]. „Structure Function Analysis of Probiotic Bacteria in Mouse Models of Chronic Intestinal Inflammation / Marie-Anne von Schillde“. München : Verlag Dr. Hut, 2013. http://d-nb.info/1045125857/34.
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Yam, Godward Georgia Nga-Mun, of Western Sydney Hawkesbury University, Faculty of Science and Technology und of Science Food and Horticulture School. „Studies on enhancing the viability and survival of probiotic bacteria in dairy foods through strain selection and microencapsulation“. THESIS_FST_SFH_YamGodward_G.xml, 2000. http://handle.uws.edu.au:8081/1959.7/411.
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In this study, strains of probiotic bacteria have been selected for tolerance to low pH, bile, sucrose, oxygen in media and low storage temperatures. Lactobacillus acidophilus 2401 and Bifidobacterium infantis 1912 were selected as strains able to survive in these conditions. These two strains were then offered further protection from the adverse conditions of food processing and storage by microencapsulation in a calcium alginate and starch gel matrix. Encapsulation in calcium alginate increases survival in yoghurt. In cheddar cheese the free L. acidophilus 2401 and B. infantis 1912 cells survived better than the encapsulated cells, probably due to the dense nature of the cheddar cheese matrix combined with the encapsulation restricting the flow of the nutrients and metabolites between the outside environment and the cells. In ice cream survival was high, probably due to the high fat and solids nature of the ice cream combined with the low storage temperature. The trial results of the laboratory scale production was consistent with the survival results for yoghurt and cheddar cheese. Incorporation of encapsulated probiotic bacteria into ice cream and cheddar cheese was acceptable by sensory standards and largely unnoticeable in comparison with the same foods without capsules. The capsules were visible and able to be felt on the tongue when eaten in yoghurt causing the product to be disliked by the panellists.Master of Science (Hons)