Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 5 uppsatser.

Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The "classical" propionibacteria are used in a variety of natural dairy fermentations where they produce natural preservatives (propionic and acetic acids and bacteriocins) and large amounts of vitamin B12. The extracellular polysaccharide (ECP) producing ability of these bacteria also make them of special interest to the food and waste water management industries as the ECP has been illustrated to playa role in the initial granule formation in upflow anaerobic bioreactor systems. There is little known on the ECP production by propionibacteria and in this study different environmental conditions that influence ECP production were studied. Nineteen different Propionibacterium strains were examined in terms of ECP production and Propionibacterium strain 278 was identified as the best ECP producer. Further studies were only done on this strain because of its high ECP production and because it was originally isolated from an anaerobic digester. The influence of temperature, pH and sucrose concentration was determined through the measurement of ECP production and medium viscosity. It was found that more ECP was produced at temperatures lower than the optimum for growth with the optimum being between 22° and 25°C. Lower initial pH conditions of the growth medium (below pH 7.0) were found to inhibit ECP production and the influence when the initial pH values were between 7.0 and 8.5, was not significant. A higher carbon: nitrogen ratio, when 8% sucrose was added, was also found to enhance the ECP production. The upflow anaerobic sludge bed (UASB) bioreactor process depends on the upward movement of soluble matter through a blanket of active methanogenic granular sludge. The long start-up times as a result of the slow granulation process, as well as the need for a speedy replacement of granules once they have been washed out of the system, are limitations that restrict the general application of this excellent waste water treatment technology. Full exploitation of this biomass immobilisation technique can thus not be realised until the granule formation conditions are defined and optimised. The precise nature of the mechanisms involved in the formation of granules and the reason for their stability, is still not fully understood. It was hypothised by Britz et al. in 1999 that, through the implementation of environmental 'stress' conditions, a shift in the population dynamics of the anaerobic community can be obtained. This results in a concurrent increase in ECP formation that appears to enhance aggregate formation. In the second study it was found that, when 'stress' conditions were applied to already formed granules, the Gram-positive lactate-utilising acidogenic population gained an advantage and more propionic acid producing bacteria were present. The propionic and acetic acid concentrations were also found to increase, and concurrently, a decrease in the growth medium pH occurred. This confirms part of the granulation hypothesis that, when granules are 'stressed', the acidogenic population dynamics change and the lactate-utilising population responds to the gradual decrease in pH and the more acid-tolerant propionic acid producing bacteria gain a competitive advantage resulting in the increase in the propionic acid concentration. When propionibacteria were added to raw sludge during the granule production process, the granules were found to be more active than when nopropionibacteria had been added. This was probably due to the ECP formation by the propionibacteria that enhances the aggregation of the granules. Enhanced granulation was thus found in the batch systems with the fatty acids formed in correlation with the model for granulation. A good correlation was evident between the hypothesis and the experimental data and the hypothesis was partially verified in this study. / AFRIKAANSE OPSOMMING: Die "klassieke" propionibakterieë word in 'n verskeidenheid van natuurlike suiwel fermantasies gebruik waarin hulle verantwoordelik in vir die produksie van natuurlike voedsel preserveermiddels (propioonsuur, asynsuur en bakteriosiene) en groot hoeveelhede vitamiene B12. Die Ekstra Sellulêre Pollisakkaried (ESP) produserende eienskap van hierdie groep bakterieë maak hulle ook van belang in die voedsel en afvoerwater beheer industrieë, aangesien gevind is dat ESP 'n rol speel in die aanvanklike granule formasie in anaerobiese bioreaktor sisteme. Daar is nog baie min bekend oor die ESP produksie van propionibakterieë en in hierdie studie is verskeie omgewings faktore wat die ESP produksie beïnvloed, bestudeer. Negentien verskillende Propionibakterium stamme was bestudeer in terme van ESP produksie en Propionibakterium stam 278 was geïdentifiseer as die stam wat die meeste ESP produseer. Verdere studies was op hierdie stam gedoen na aanleiding van sy hoë ESP produksie en omdat dit oorspronklik uit 'n anaerobiese verteerder geisoleer is. Die invloed van termperatuur, pH en sukrose konsentrasie was bepaal deur die meting van die ESP produksie en die medium viskositeit. Dit was gevind dat meer ESP geproduseer was by temperature laer as die optimum vir groei, met die optimum temperatuur tussen 22° en 25°C. Dit is ook gevind dat laer aanvangs groei-medium pH (laer as pH 7.0), ESP produksie inhibeer. Die invloed van die aanvangs groei-medium pH tussen 7.0 en 8.5 was egter nie betekenisvol nie. Dit is ook gevind dat 'n hoër koolstof tot stikstof verhouding, verkry deur die byvoeging van 8% sukrose, die ESP produksie verhoog. Die "upflow anaerobic sludge blanket" (UASB) proses vind plaas as gevolg van die opwaarste beweging van opgeloste organiese materiaal deur 'n granule bed van aktiewe metanogeniese granulêre slyk. Die lang 'start-up' tye as gevolg van die stadige granulasie proses, en die nodigheid om 'n vinnige verplasing van granules te hê nadat dit uit die sisteem gewas is, is beperkings wat die algemene toepassing van hierdie fantastiese afvoerwater tegnologie, strem. Volle implementering van hierdie biomassa immobilisereings tegniek kan dus nie plaasvind voordat die granule formasie gedefinieer en geoptimiseer is nie. Die presiese eienskappe van die meganismes betrokke en die formasie van die granules en die rede vir hul stabiliteit word egter nog nie ten volle verstaan nie. Volgens 'n hipotese deur Britz et al. (1999), vind 'n verskuiwing in die populasie dinamika van die anaerobiese gemeenskap plaas tydens die implementasie van omgewings 'stress' toestande. Die resultaat is 'n verhoging in ESP produksie en 'n gevolglike verbetering in die granulasie proses. In die tweede studie was dit gevind dat, wanneer 'stress' toestande op die reeds gevormde granulasie toegepas word, die Gram-positiewe laktaat-benuttende asetogeniese populasie voordeel geniet en meer propioonsuur produserende bakterieë was teenwoordig. Die propioonsuur en asynsuur konsentrasies het ook verhoog en met 'n gevolglike daling in die groei-medium se pH. Dit bevestig 'n gedeelte van die hipotese dat, wanneer die granules onder 'stress' geplaas word, die asetogeniese populasie dinamika verander en die laktaat-benuttende populasie reageer tot die gedeeltelike afname in pH. Die meer suur-tolerante propioonsuur produserende bakterieë verkry 'n kompeterende voordeel en gevolglik is daar 'n verhoging in propioonsuur konsentrasie. Propionibakterieë was gevoeg by die onbehandelde slyk gedurende die granule produksie proses, en daar is gevind dat meer aktiewe granules gevorm word as andersins. Dit is moontlik as gevolg van die die ESP produksie van propionibakterieë wat die granulasie versnel het. Verbeterde granulasie was dus verkry in die sisteme waar propionibakterieë bygevoeg is. Vetsuur analises het gedui dat die gevormde vetsure ook in korrelasie was met die model van granulasie. Goeie korrelasie was dus verkry tussen die hipotese en die eksperimentele data en die hipotese is gedeeltelik bewys in hierdie studie.

Propionibacterium freudenreichii est une bactérie très utilisée par l’industrie laitière. Elle appartient aux Actinomycètes connus pour leur survie pendant de longues périodes, dans des conditions environnementales défavorables. Pour mieux comprendre ce phénomène, la caractérisation phénotypique de 8 souches de P. freudenreichii a été réalisée sur 11 jours dans un milieu en carence nutritionnelle. Le taux de survie bactérienne a été mesuré par densité optique, par énumération et évaluation de la viabilité cellulaire. En outre, l’absence de lyse cellulaire a été évaluée par PCR quantitative. La croissance de P. freudenreichii a été décrite en phases exponentielle, stationnaire, stationnaire tardive et survie à long terme.Dans nos conditions expérimentales pendant la période de survie à long terme, les bactéries sont restées viables. La caractérisation phénotypique a montré que P. freudenreichii CIRM-BIA138 était la plus résistante à la carence nutritionnelle et entrait dans un état viable mais non-cultivable. Cette souche a été utilisée pour une étude fonctionnelle par RNA-Seq ainsi que pour des analyses biochimiques sur les surnageants de culture, en phases exponentielle et stationnaire. L’association de ces données transcriptomiques et métabolomiques a permis de déduire les stratégies impliquées dans la survie de cette bactérie. La préparation à l’état de dormance, la diminution du métabolisme et l’utilisation de sources alternatives d’énergie semblent impliquées dans l’adaptation et la persistence de P. freudenreichii CIRM-BIA138 en carence nutritionnelle durant de long / Propionibacterium freudenreichii is a dairy bacterium belonging to the Actinobacteria group, which is known to survive for long periods in harsh environmental conditions. In order to investigate the long-term survival phenomenon in P. freudenreichii, 8 strains were phenotypically characterized for a period of 11 days in nutrient shortage condition. Bacterial survival rate was assessed by optical density, CFU counting and live-dead cellular viability. In addition, the absence of cell lysis was evaluated by quantitative PCR. P. freudenreichii growth phases were classified as exponential, stationary, late stationary and long-term survival. Moreover, it was observed that bacterial viability was maintained during long-term survival.Phenotypical characterization indicated that P. freudenreichii CIRM-BIA138 was more resistant to nutrient shortage being able to enter into a viable but nonculturable dormant state. In addition, functional studies of this strain were conducted by RNA-Seq on cultures sampled in exponential and stationary growth phases. Concomitantly, several biochemical analyses were carried out on the culture supernatant. An integrative approach of metabolomic and transcriptomic data allowed us to infer strategies associated with the survival of this bacterium, such as preparation for the dormant state, slow down of metabolic activity and utilization of alternative sources of energy, which altogether might allow P. freudenreichii CIRM-BIA 138 to adapt and persist through nutrient shortage for long periods.

Abstract Acne is a common skin disease that affects nearly every teenager but in some cases it persists into adulthood as a chronic disease. Acne severity ranges from mild comedonal to severe cystic and scarring disease. The pathogenesis of acne is multifactorial: increased sebum production, hormonal influences, the hypercornification of pilosebaceous ducts, overgrowth of Propionibacterium acnes (P. acnes) and inflammation around pilosebaceous follicles are considered to be the main pathogenetic factors but few further details are known. The role of innate immunity in the pathogenesis of acne has been studied quite extensively, but the contribution of adaptive immune responses is not well characterized. Although isotretinoin has been the most potent medication for acne over 30 years, its mode of action is partially unknown. Furthermore, modern 16S ribosomal RNA (rRNA) gene amplicon sequencing based methods allow quantification of the abundance of skin bacteria, but these culture-independent techniques have not yet been used to assess the effect of systemic treatments, isotretinoin and tetracycline antibiotics on acne skin microbiota. In this study the innate and adaptive immune responses in the skin of acne patients were investigated. Skin biopsies were taken from early-stage acne lesions and from uninvolved skin of acne patients, and the samples were examined for the expression of cytokines, chemokines, transcription factors and antimicrobial peptides, using real-time polymerase chain reaction (PCR). In addition, the skin biopsies were examined by immunohistochemistry and Luminex technology, which was also used in the determination of cytokine levels in acne patients’ serum samples. The skin microbiota of swab samples was investigated using 16S rRNA gene amplicon sequencing. We found that innate and adaptive immune responses, in particular the activation of the IL-17/Th17 axis, are involved in early-stage acne lesions. Furthermore, the expression of effector cytokine TGF-β and transcription factor of regulatory T cells (Tregs) FoxP3 mRNA was reduced in acne patients’ uninvolved skin compared to normal skin of healthy controls. Isotretinoin has no direct effect on innate and adaptive immune responses in newly formed acne lesions. It did, however, modify some innate immune responses: the expression of IL-1β and toll-like receptor 2 (TLR2) mRNA was reduced in uninvolved skin of acne patients, and the number of CD68+ macrophages increased in acne patients’ skin with isotretinoin treatment. After six weeks’ treatment, the abundance of P. acnes was similarly reduced with either isotretinoin or lymecycline treatment. However, previous studies and clinical experience show that isotretinoin is more clinically effective against acne than tetracyclines, probably because of the effect of isotretinoin on sebaceous glands and sebum excretion. Acne is a disease, which at its worst results in significant scarring. Therefore it is important to understand the immunological factors behind its pathogenesis. Our findings show that both adaptive and innate immunity play an important role. Isotretinoin, although currently the most potent anti-acne drug, does not directly affect the adaptive immune response and therefore new medications are required to control the relevant immune responses, especially in severe cystic or fulminant acne. / Tiivistelmä Akne on yleinen ihosairaus, joka koskettaa lähes jokaista teini-iässä ja jatkuu osalla kroonisena sairautena läpi aikuisiän. Aknen vaikeusaste vaihtelee lievästä vaikeisiin, arpeuttaviin tautimuotoihin. Aknen patogeneesin tiedetään olevan monitekijäinen. Tärkeimmät aknen syntyyn vaikuttavat tekijät ovat lisääntynyt talineritys hormonien, erityisesti androgeenien vaikutuksesta, talirauhaskarvatuppitiehyen tukkeutuminen, Propionibacterium acnes (P. acnes) – bakteerin liikakasvu sekä tulehdusreaktio talirauhaskarvatupen ympärillä. Synnynnäisen immuniteetin roolia aknen synnyssä on tutkittu paljon, sen sijaan hankittua immuniteettia huomattavasti vähemmän. Myöskään yli 30 vuotta käytössä olleen tehokkaimman aknelääkkeen, isotretinoiinin, vaikutusmekanismia ei täysin tiedetä. Lisäksi systeemilääkkeiden, isotretinoiinin ja tetrasykliiniryhmän antibioottien, vaikutusta akneihon bakteeristoon ei ole tutkittu moderneilla, polymeraasiketjututkimuksiin (PCR) perustuvilla menetelmillä. Tässä tutkimuksessa selvitettiin synnynnäisiä ja hankittuja immuunireaktiota aknea sairastavien ihossa ja isotretinoiinin vaikutusta näihin reaktioihin. Tutkimuksessa hyödynnettiin aknepotilaiden ihokoepaloja, joista tutkittiin sytokiinien, kemokiinien, transkriptiotekijöiden sekä antimikrobisten peptidien ilmentymistä reaaliaikaisella PCR-menetelmällä. Lisäksi ihokoepaloja tutkittiin immunohistokemiallisilla värjäyksillä ja Luminex-menetelmällä, jota hyödynnettiin myös sytokiini-tasojen määrittämiseen aknepotilaiden seeruminäytteistä. Aknea sairastavien ihon bakteeristoa tutkittiin 16S ribosomaalisen RNA:n geenien sekvensointiin pohjautuvalla menetelmällä. Väitöstutkimuksessa havaitsimme, että varhaisvaiheen aknemuutoksessa käynnistyvät sekä synnynnäisen että hankitun immuniteetin vasteet. Erityisesti IL-17/Th17-akseli on aktivoitunut. Lisäksi aknea sairastavien terveellä iholla tulehduksen välittäjäaineen TGF-1β ja transkriptiotekijän FoxP3 ilmeneminen oli alentunut verrattuna terveihoisiin kontrolleihin. Isotretinoiinilla ei ole suoraa vaikutusta synnynnäisen ja hankitun immuniteetin reaktioihin jo olemassa olevissa varhaisen vaiheen aknemuutoksissa. Aknea sairastavien terveessä ihossa isotretinoiini muokkasi luontaisen immuniteetin vasteita mm. vähentämällä tollin kaltaisen reseptorin (TLR)- 2 ja tulehduksen välittäjäaineen IL-11β ilmenemistä sekä lisäämällä makrofagien kertymistä tulehduspaikalle. Kuuden viikon hoito isotretinoiinilla tai lymesykliinillä vähentää yhtä tehokkaasti aknealueilla P. acnes -bakteerin suhteellista osuutta ihon bakteeristosta. Isotretinoiini on kuitenkin antibiootteja tehokkaampi aknelääke ja lisäksi hoitovaste saavutetaan pitemmäksi aikaa, mikä johtunee isotretinoiinin vaikutuksesta talirauhasiin ja talinerityksen vähentämisestä. Aknen tulehdusmekanismien ymmärtäminen on tärkeää taudissa, joka pahimmillaan johtaa merkittävään arpeutumiseen. Tutkimuksemme perusteella hankittu immuniteetti on tärkeässä roolissa synnynnäisen immuniteetin aktivoitumisen rinnalla aknen synnyssä. Tehokkain aknelääke, isotretinoiini ei vaikuta hankittuun immuunivasteeseen, minkä vuoksi jatkossa tarvitaan uusia lääkkeitä isotretinoiinin rinnalle tulehduksen nopeaan hillitsemiseen vaikeissa aknemuodoissa.

No / Propionibacterium acnes is the target of antimicrobial treatments for acne vulgaris. Acquired resistance to erythromycin, clindamycin and tetracyclines has been reported in strains from diverse geographical loci, but the molecular basis of resistance, via mutations in genes encoding 23S and 16S rRNA, respectively, has so far only been elucidated for isolates from the U.K. The study set out to determine whether similar or different resistance mechanisms occur in resistant P. acnes isolates from outside the U.K. The phenotypes and genotypes of 73 antibiotic-resistant strains of P. acnes obtained from the skin of acne patients in the U.K., U.S.A., France, Germany, Australia and Japan were compared. Antibiotic susceptibilities were determined by minimum inhibitory concentration (MIC) measurements, and polymerase chain reaction and DNA sequencing were used to identify mutations in genes encoding rRNA. Most erythromycin-resistant isolates (MIC90¿ 512 ¿g mL¿1) were cross-resistant to clindamycin but at a much lower level (MIC90¿ 64 ¿g mL¿1). As in the U.K., resistance to erythromycin was associated with point mutations in 23S rRNA in 49 of 58 strains. An A¿G transition at Escherichia coli equivalent base 2058 was present in 24 strains. This gave a unique cross-resistance phenotype against a panel of macrolide, lincosamide and type B streptogramin antibiotics. Two further point mutations (at E. coli equivalent bases 2057 and 2059) were identified (in three and 22 isolates, respectively) and these were also associated with specific cross-resistance patterns originally identified in isolates from the U.K. However, nine of 10 erythromycin resistant-strains from Germany did not exhibit any of the three base mutations identified and, in six cases, cross-resistance patterns were atypical. Consistent with previous U.K. data, 34 of 38 tetracycline-resistant strains carried a base mutation at E. coli 16S rRNA equivalent base 1058. Tetracycline-resistant isolates displayed varying degrees of cross-resistance to doxycycline and minocycline, but isolates from the U.S.A. had higher MICs for minocycline (4¿16 ¿g mL¿1) than isolates from other countries and, in particular, Australia. All the P. acnes isolates resistant to one or more of the commonly used antiacne antibiotics were sensitive to penicillin, fusidic acid, chloramphenicol and the fluoroquinolone, nadifloxacin. All but one isolate (from the U.K.) were sensitive to trimethoprim. This study shows that 23S and 16S mutations identified in the U.K. conferring antibiotic resistance in P. acnes are distributed widely. However, resistant strains were isolated in which mutations could not be identified, suggesting that as yet uncharacterized resistance mechanisms have evolved. This is the first report of high-level resistance to minocycline and is of concern as these strains are predicted to be clinically resistant and are unlikely to remain confined to the U.S.A. Epidemiological studies are urgently required to monitor how resistant strains are selected, how they spread and to ascertain whether the prevalence of resistance correlates with antibiotic usage patterns in the different countries.

Thesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2016. / In South Africa malnutrition exists due to inadequate dietary intake of micronutrients which is one of the major causes of vitamin deficiencies leading to disease. The treatment of malnutrition over the past years has been a considerable burden on the South African economy. Therefore, food fortification is one of the current strategies used to minimize malnutrition by increasing the nutritional value of staple foods. Commercial dairy products and pharmaceutical nutritional products (food supplements) in South Africa have been developed and produced for affluent consumers. Hence the need to develop an affordable fortified dairy product for the majority of South Africans prompted this study aimed at using a “naturally” fortified kefir beverage with vitamin B12 and folate to increase B-vitamins levels. Since Propionibacterium freudenreichii and Streptococcus thermophilus are known to be good producers of vitamin B12 and folate, respectively, and propionibacteria has the ability to grow symbiotically in the presence of lactic acid bacteria, the inclusion of these organisms with the kefir grains was an achievable objective. In order to conduct the analysis of vitamin B12 and folate in the samples, sample extraction and HPLC assay techniques were developed. The extraction of vitamin B12 and folate were achieved by using KCN extraction buffer and the trienzymatic method, respectively. The samples were also subjected to purification and concentration using solid phase extraction for optimum results. All standards and samples were flushed with nitrogen gas and stored for a maximum of 2 weeks at –20°C to prevent B-vitamin deterioration. The HPLC assembly for the vitamin B12 analysis included a Luna C18 column and a diode array detector (DAD) for the detection and quantification. For the folate analysis it included a Zorbax SB-C18 and Luna C18 columns in tandem and the fluorescence detector (FLD) was used for the detection and quantification of THF, 5-CH3-THF and 5-CHO-THF, while the DAD was used for PGA and pteroyltri-γ-L-glutamic acid concentration in the samples.

Orientador: Ary Fernandes Junior / Resumo: Os óleos essenciais (OE) são produtos do metabolismo secundário da planta e são conhecidos pelas suas propriedades antimicrobianas. O principal componente do OE da palmarosa é o geraniol (70-80%). A incorporação de compostos da biodiversidade agrega valor as formulações dermocosméticas. OEs são uma boa opção devido à semelhança estrutural com o equilíbrio hidro-lipídico da pele. Assim, o objetivo do estudo foi avaliar a atividade antibacteriana desses compostos e o desenvolvimento de protótipos de dermocosméticos com nanopartículas para o tratamento da acne vulgar. Nanoemulsões com OE e geraniol foram preparadas de acordo com os valores do equilíbrio hidrofílico-lipofílico (EHL) e a caracterização das nanoemulsões seguiram os parâmetros da ANVISA (2004) para testes preliminares de estabilidade. Foram preparadas dez formulações. Nanoemulsões especiais contendo nanopartículas de prata (AgNP) foram preparadas e testadas contra C. acnes. Os ensaios de microtitulação com resazurina (REMA) foram realizados para determinar a Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM) para o OE de palmarosa e geraniol contra cepas American Type Culture Collection (ATCC) de Cutibacterium acnes 11827, 11828 e 6919. A curva de sobrevivência (CS) foi realizada para analisar o sinergismo entre os compostos e a clindamicina contra C. acnes, cepa 6919. As formulações foram estáveis ao pH, condutividade elétrica, densidade, centrifugação e análise de stress térmico. Anális... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Essential oils (EO) are secondary metabolism products of plant and they are known for antimicrobial properties.The major component of palmarosa EO is geraniol (70-80%). Incorporation of compounds of biodiversity guarantee value to dermocosmetic formulations. EOs are good option due to structural similarity with skin hydro-lipid balance. Thus, the desire was to evaluate the antibacterial activity to these compounds and the development of dermocosmetic prototypes with nanoparticles to treat acne vulgaris. Nanoemulsion with EO and geraniol were prepared according to values of lipophilic-hydrophilic balance (LHB) and nanoemulsions characterization followed the ANVISA (2004) parameters for preliminary stability tests. Ten formulations were prepared. Special nanoemulsion containing silver nanoparticles (AgNP) was prepared and tested against C. acnes. Resazurin Microtiter Assays (REMA) was performed to determine the Minimum inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for palmarosa EO and geraniol against American Type Culture Collection (ATCC) strains of Cutibacterium acnes 11827, 11828 and 6919. The target of Time Kill Curve (TKC) test was determinate the synergism between compounds and clindamycin to C. acnes strain 6919. The formulations were stable to pH, electrical conductivity, density, centrifugation and thermal stress analysis. Analysis of size, zeta potential (ZP) and polydispersity index (PDI) were between 60 and 165 d.nm; -16.6 and -34.8 mv... (Complete abstract click electronic access below) / Mestre

<p>An introduction to bacterial polysaccharides and the methods for structural determination are described in the first two parts of the thesis.</p><p>In a structural elucidation of bacterial polysaccharides NMR experiments are important as is component analysis. A short description of immunochemical methods such as enzyme immunoassays is included. Two NMR techniques used for interaction studies, trNOE and STD NMR, are also discussed. </p><p>The third part of the thesis discusses and summarizes the results from the included papers. The structures of the exopolysaccharides produced by two lactic acid bacteria are determined by one- and two dimensional NMR experiments. One is a heteropolysaccharide produced by <i>Streptococcus thermophilus</i> and the other a homopolysaccharide produced by <i>Propionibacterium freudenreichii</i>. The structure of an acidic polysaccharide from a marine bacterium with two serine residues in the repeating unit is also investigated. The structural and immunological relationship between two O-antigenic polysaccharides from <i>Escherichia coli</i> strain 180/C3 and O5 is discussed and investigated. Finally, interaction studies of an octasaccharide derived from the <i>Salmonella enteritidis</i> O-antigen and a bacteriophage are described which were performed with NMR experiments.</p>

An introduction to bacterial polysaccharides and the methods for structural determination are described in the first two parts of the thesis. In a structural elucidation of bacterial polysaccharides NMR experiments are important as is component analysis. A short description of immunochemical methods such as enzyme immunoassays is included. Two NMR techniques used for interaction studies, trNOE and STD NMR, are also discussed. The third part of the thesis discusses and summarizes the results from the included papers. The structures of the exopolysaccharides produced by two lactic acid bacteria are determined by one- and two dimensional NMR experiments. One is a heteropolysaccharide produced by Streptococcus thermophilus and the other a homopolysaccharide produced by Propionibacterium freudenreichii. The structure of an acidic polysaccharide from a marine bacterium with two serine residues in the repeating unit is also investigated. The structural and immunological relationship between two O-antigenic polysaccharides from Escherichia coli strain 180/C3 and O5 is discussed and investigated. Finally, interaction studies of an octasaccharide derived from the Salmonella enteritidis O-antigen and a bacteriophage are described which were performed with NMR experiments.

The aim of this diploma thesis was to investigate the effect of surfactants and cosmetic polysaccharides on skin parameters and its microbiome. Three surfactants were tested to determine their effect: Sodium Dodecyl Sulfate (SDS), Cocamidopropyl Betaine (CAPB), Decylglucoside (DG). Distilled water was also used for comparison. For the next part of the experimental work were selected 6 polysaccharides: high molecular weight Hyaluronic Acid (HMW HA), very low molecular weight Hyaluronic Acid (VLMW HA), Sodium Caproyl Hyaluronate (CaproylHA), Sodium Carboxymethyl -Glucan (NaCMG), Schizophyllan and Glucomannan. For comparison, placebo and untreated control (only CAPB treatment) were also included in the tests. The first part of the work is a literature search on the assigned topic, which contains the following parts: skin anatomy and its biophysical properties, skin microbiome and its functions, description of used surfactants and polysaccharides. The experimental part is mainly focused on bioengineering methods for evaluation of skin parameters and qRT-PCR to determine the relative proportion of main bacterial species of skin microbiome. First, the effect on the CT gene of 16S rDNA was analysed, and Propionibacterium acnes and Staphylococcus epidermidis strains were selected for further analysis. In conclusion are presented an overview of all properties of selected substances and assessment of their application in cosmetics.