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: Les grains de kéfir sont des ferments lactiques constitués d'une microflore complexe et diversifiée. Celle d'un grain de kéfir (KJ) a été caractérisée par une approche méthodologique classique d'isolements microbiens sur des milieux de culture sélectifs et, pour les bactéries lactiques, par une approche indépendante d'isolements bactériens par culture. Cette dernière consistait en l'analyse de la séquence des régions V1 et V2 de l'ADNr 16S, amplifiées à partir de l'ADN extrait du grain. La sensibilité de la méthode a été augmentée à cette occasion en dissociant les amplifications géniques des populations lactiques minoritaires et majoritaires du grain. La flore identifiée dans le grain KJ comprenait Acetobacter sp., Kazachstania exigua, Lactobacillus kefiranofaciens subsp. kefirgranum, Lb. kefiri, Lb. parakefiri, Lactococcus lactis subsp. lactis et Leuconostoc mesenteroides, et était dépourvue de microcoques, de pédiocoques, de Weissella viridescens, de bactéries indicatrices de défauts d'hygiène, de Salmonella sp. et de Listeria monocytogenes. Dans le but de vérifier le caractère complet des espèces mises à jour, une reconstitution du grain à partir des micro-organismes qui en ont été isolés a été envisagée. Des conditions expérimentales favorables à la formation de grains dans un substrat lacté ont été recherchées à partir d'extraits du grain KJ renfermant un consortium microbien a priori complet. Ces essais de reconstitution n'ont pas conduit à la formation de grains de kéfir mais l'un d'eux a conduit à la formation de biofilms. Cet évènement a été reproduit dans du lait de façon répétable avec des consortiums reconstitués à partir des micro-organismes individuels isolés du grain KJ.

<p>Conventional end-of-pipe solutions for wastewater treatment have been criticized from a sustainable view-point, in particular regarding recycling of nutrients. The integration of hydroponic cultivation into a wastewater treatment system has been proposed as an ecological alternative, where nutrients can be removed from the wastewater through plant uptake; however, cultivation of plants in a temperate climate, such as Sweden, implies that additional energy is needed during the colder and darker period. Thus, treatment capacity, additional energy usage and potential value of products are important aspects considering the applicability of hydroponic wastewater treatment in Sweden.</p><p>To enable the investigation of hydroponic wastewater treatment, a pilot plant was constructed in a greenhouse located at Överjärva gård, Solna, Sweden. The pilot plant consisted of several steps, including conventional biological processes, hydroponics, algal treatment and sand filters. The system treated around 0.56-0.85 m3 domestic wastewater from the Överjärva gård area per day. The experimental protocol, performed in an average of twice per week over a period of three years, included analysis and measurements of water quality and physical parameters. In addition, two studies were performed when daily samples were analysed during a period of two-three weeks. Furthermore, the removal of pathogens in the system, and the microbial composition in the first hydroponic tank were investigated.</p><p>Inflow concentrations were in an average of around 475 mg COD/L, 100 mg Tot-N/L and 12 mg Tot-P/L. The results show that 85-90% of COD was removed in the system. Complete nitrification was achieved in the hydroponic tanks. Denitrification, by means of pre-denitrification, occurred in the first anoxic tank. With a recycle ratio of 2.26, the achieved nitrogen removal in the system was around 72%. Approximately 4% of the removed amount of nitrogen was credited to plant uptake during the active growth period. Phosphorus was removed by adsorption in the anoxic tank and sand filters, natural chemical precipitation in the algal step induced by the high pH, and assimilation in plants, bacteria and algae. The main removal occurred in the algal step. In total, 47% of the amount of phosphorus was removed. Significant recycling of nitrogen and phosphorus through harvested biomass has not been shown. The indicators analysed for pathogen removal showed an achieved effluent quality comparable to, or better than, for conventional secondary treatment. The microbial composition was comparable to other nitrifying biological systems. The most abundant phyla were Betaproteobacteria and Planctomycetes.</p><p>In Sweden, a hydroponic system is restricted to greenhouse applications, and the necessary amount of additional energy is related to geographic location. In conclusion, hydroponic systems are not recommended too far north, unless products are identified that will justify the increased energy usage. The potential for hydroponic treatment systems in Sweden lies in small decentralized systems where the greenness of the system and the possible products are considered as advantages for the users.</p>

Conventional end-of-pipe solutions for wastewater treatment have been criticized from a sustainable view-point, in particular regarding recycling of nutrients. The integration of hydroponic cultivation into a wastewater treatment system has been proposed as an ecological alternative, where nutrients can be removed from the wastewater through plant uptake; however, cultivation of plants in a temperate climate, such as Sweden, implies that additional energy is needed during the colder and darker period. Thus, treatment capacity, additional energy usage and potential value of products are important aspects considering the applicability of hydroponic wastewater treatment in Sweden. To enable the investigation of hydroponic wastewater treatment, a pilot plant was constructed in a greenhouse located at Överjärva gård, Solna, Sweden. The pilot plant consisted of several steps, including conventional biological processes, hydroponics, algal treatment and sand filters. The system treated around 0.56-0.85 m3 domestic wastewater from the Överjärva gård area per day. The experimental protocol, performed in an average of twice per week over a period of three years, included analysis and measurements of water quality and physical parameters. In addition, two studies were performed when daily samples were analysed during a period of two-three weeks. Furthermore, the removal of pathogens in the system, and the microbial composition in the first hydroponic tank were investigated. Inflow concentrations were in an average of around 475 mg COD/L, 100 mg Tot-N/L and 12 mg Tot-P/L. The results show that 85-90% of COD was removed in the system. Complete nitrification was achieved in the hydroponic tanks. Denitrification, by means of pre-denitrification, occurred in the first anoxic tank. With a recycle ratio of 2.26, the achieved nitrogen removal in the system was around 72%. Approximately 4% of the removed amount of nitrogen was credited to plant uptake during the active growth period. Phosphorus was removed by adsorption in the anoxic tank and sand filters, natural chemical precipitation in the algal step induced by the high pH, and assimilation in plants, bacteria and algae. The main removal occurred in the algal step. In total, 47% of the amount of phosphorus was removed. Significant recycling of nitrogen and phosphorus through harvested biomass has not been shown. The indicators analysed for pathogen removal showed an achieved effluent quality comparable to, or better than, for conventional secondary treatment. The microbial composition was comparable to other nitrifying biological systems. The most abundant phyla were Betaproteobacteria and Planctomycetes. In Sweden, a hydroponic system is restricted to greenhouse applications, and the necessary amount of additional energy is related to geographic location. In conclusion, hydroponic systems are not recommended too far north, unless products are identified that will justify the increased energy usage. The potential for hydroponic treatment systems in Sweden lies in small decentralized systems where the greenness of the system and the possible products are considered as advantages for the users. / QC 20101014

En mängd olika faktorer har visat sig påverka smakperceptionen. Ålder, fetma och den mikrobiellamiljön i munhålan är bara några exempel på omständigheter som kan resultera i smak-skillnader.Denna litteraturstudie syftar till att översiktligt granska de mekanismer som är involverade i munnenssmakuppfattning samt andra smakpåverkande faktorer såsom sjukdomar, kostvanor och oralametaboliter för att sedan utvärdera om samband existerar mellan dessa. Metabolismen som utförs avmikrober i saliv och tungfilm diskuteras också som potentiella variabler i smakuppfattningen, baseratpå att en adaption (smak-anpassning) i munhålan kan orsaka lägre detektionströsklar. Studienpresenterar smakförstärkarna miraculin och curculin, då dessa har en förmåga att förstärka sötasmaker genom modulering av smakreceptorerna. Alla dessa processer i munhålan är avgörande för attförstå komplexiteten i individers smakuppfattning. Den mikrobiella aktiviteten i munnen tyckspåverka smakperceptionen, därför uppmuntras ytterligare studier kring oral mikroflora och smak föratt vidare utvärdera dess korrelation. Insamlad information kan vara av relevans för biotekniskaändamål eller sensoriska tester. / Many different factors have been shown to influence taste perception. Age, obesity, olfactoryresponses, sensitivity to the chemical 6-n-propylthiouracil (PROP-sensitivity), and even the microbialcomposition of the oral cavity are just a few examples of circumstances related to taste differences.This literature review aims to briefly assess taste transduction mechanisms and other taste-affectingfactors such as disease, dietary patterns, and oral metabolites to evaluate if correlations exist. Themetabolites made by microbes present in saliva and tongue film are also being discussed as variablesin the subjectiveness of taste, suggesting that adaptation in the oral cavity is causing lower detectionthresholds for specific tastes. A section presenting flavor-enhancers exemplifies the ability ofparticular proteins to amplify sweet tastes through the modulation of sweet receptors. Excludingolfactory responses, these in-mouth processes are crucial to understanding the complexity of flavor.Microbial activity in the mouth appears to play a role in the individuality of taste. Since this is anemerging area of research, future studies will help identify and characterize the connections betweentaste and oral microbiota. Assembled information in this review could also be relevant forbiotechnical purposes or sensory tests.