Role of PsbO isoforms in Arabidopsis thaliana Abstract Photosystem II (PSII) uses sunlight to catalyze water oxidation and reduce plastoquinone. Water oxidation takes place in oxygen evolving complex (OEC). OEC is stabilized by extrinsic subunits of PSII. The largest and most important of them is PsbO, manganese-stabilizing protein which can be found in all known oxygenic photosynthetic organisms. Model plant Arabidopsis thaliana expresses two isoforms of psbO gene, namely PsbO1and PsbO2.Mutants psbo1 and psbo2 lacking PsbO1 and PsbO2, respectively, recently brought new findings on the particular roles of isoforms in maintaining photosynthesis. PsbO1 is commonly considered as the main isoform facilitating water splitting, whereas PsbO2 is believed to be involved in PSII repair process (replacement of photodamaged D1 subunit). This work focuses on particular roles of Arabidopsis PsbO isoforms in maintaining photosynthesis with special focus on response to light stress. Mutants psbo1, psbo2 and wild type plants Col-0 were used for extensive biochemical investigation. Our aim was to find out what is the impact on overall thylakoid structure and composition in mutants. Furthermore, to investigate response to light stress in wild type regarding to yields of particular subcompartments, changes in photosystem II...

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Målet med projektet var att beskriva de biogeokemiska processer som påverkar grundvattenkvaliteten i Tranås nya vattentäkt. Grundvattenbildningen på platsen sker framför allt genom inducerad infiltration av vatten från sjön Sommen. I syfte att avskilja järn och mangan pumpas grundvattnet upp, syresätts och injekteras sedan i brunnar för att skapa en oxiderande grundvattenmiljö. Metoden kallas Vyredox. Med en 15 månader lång provtagningsserie och automatiskt registrerade processvärden och driftdata från anläggningen som underlag görs i rapporten bedömningar om trender, säsongsmässiga variationer och samband mellan driftsituation och kvalitet på utgående vatten. Dessutom görs en provtagning på flera platser runt anläggningen för att undersöka rumsliga variationer av grundvattnets sammansättning. Den statistiska metoden principalkomponentanalys har använts i syfte att utreda vattnets ursprung. Arbetet resulterade i en beskrivning av vattenkvalitetens utveckling under vattentäktens första år i drift, och en diskussion om framtida scenarion. En slutsats är att en form av mark/vatten-kemisk jämvikt uppstår i akviferen ungefär 6 månader efter det att den nya anläggningen började köras. En annan slutsats är att manganhalten kommer minska i framtiden. Provtagningen visar att utgående råvatten i högre grad än vad som förutspåtts innehåller vatten med annat ursprung än sjön. Samband mellan driftsituation och vattenkvalitet förtydligas och resultaten pekar mot att det utgående vattnets sammansättning påverkas av de förändrade flödesvägar och avsänkningar kring uttagsbrunnarna som uppstår vid olika driftfall.

Dricksvatten är en grundsten till ett välmående samhälle. Kvaliteten på dricksvatten påverkas av vilken typ av råvattenkällor som används samt hur dricksvattenberedning utförs i ett vattenverk. Om kvaliteten försämras kan det tyda på att dricksvattenberedning inte är optimal eller att kvaliteten i råvattenkällor har förändrats. Sandvikens kommun har haft återkommande problem med bruna och svarta missfärgningar på dricksvatten. Bruna och svarta missfärgningar kan orsakas av järn och mangan som oxideras i distributionsnätet. Vid oxidation av mangan bildas mangandioxid som kan påskynda korrosion. Livsmedelsverket har satt ett gränsvärde för järn och mangan i dricksvatten för att motverka bildande av fällningar i distributionsnätet. Syftet med examensarbetet är att undersöka om missfärgningarna kan bero på höga järn- och manganhalter i dricksvattnet som produceras vid Rökebo vattenverk i Sandvikens kommun. Examensarbetet utfördes med vattenprovtagning samt praktiska studier som involverade analyser av mangan, järn och mangandioxid i dricksvatten från användare samt statistiska analyser. Den statistiska analysen av mangan visade att manganhalter var som högst närmast Rökebo vattenverk. Inga andra statistiska samband har fastställts. Analysen av mangan visade att 20 av 31 vattenprover låg över gränsvärdet för dricksvatten. Gränsvärdet för mangan överskreds redan vid Rökebo vattenverk. För järn låg 2 av 24 vattenprover över gränsvärdet. Analysen av mangandioxid visade förekomst av manganoxiderande mikroorganismer i Sandvikens distributionsnät. Manganet som skickas ut från Rökebo vattenverk kan gynna mikroorganismer och kan öka bildning av mangandioxid som verkar korrosivt på gjutjärnsrör, därmed kan Rökebo vattenverks sammansättning på dricksvattnet påverka eller påskynda korrosion på distributionsnätet. Teoretiskt sätt kan vattenmissfärgningar som har upplevts i Sandvikenskommun bero på de höga manganhalterna. Det går dock inte att utesluta att missfärgningar kan bero på andra faktorer då resultatet inte gav något statistiskt samband mellan missfärgning och järn- och manganhalt. Ytterligare studier krävs för att fastställa alla orsaker bakom missfärgat dricksvatten i Sandvikens kommun. Problematiken med höga manganhalter bör lösas oavsett om det är den främsta orsaken bakom vattenmissfärgning eller inte. Manganhalterna är höga i nuläget och både järn samt mangan kommer troligtvis att öka i råvatten på grund av klimatförändringar. Om vattenverket fortsättningsvis blandar yt- och grundvatten kan problematiken lösas genom att installera en statisk mixer samt införa ett avskiljningssteg för järn och mangan. Vid val av en biologisk avskiljningsmetod kan mikroorganismer från distributionsnätet användas. / Drinking water is a cornerstone to a prosperous society. The quality of drinking water is affected by the type of raw-water sources and how drinking water treatment is carried out in a drinking water treatment plant. If the quality of the drinking water deteriorates, it may indicate that the drinking water treatment is not optimal or that the quality of raw-water sources has changed.The municipality of Sandviken in Sweden has had recurring problems with brown and black discolorations of the drinking water. Brown and black discolorations can be caused by oxidation of iron and manganese in the drinking water distribution system. The oxidation of manganese leads to the formation of manganese dioxide that can accelerate the corrosion processes of cast iron pipes. The Swedish Food Agency has set a limit value for the concentration of iron and manganese in drinking water to prevent the formation of precipitates in the drinking water distribution system. The aim of the study is to investigate whether the discolorations are due to high levels of iron and manganese in the drinking water. Water samples were collected to practically and statistically analyse the concentrations of iron, manganese and the formation of manganese dioxide. The statistical analysis showed that the levels of manganese were at their highest closest to the drinking water treatment plant. No other statistical correlations have been established. The analysis of manganese showed that 20 out of 31 water samples were above the limit value. The limit value for manganese was already exceeded at the drinking water treatment plant. The analysis of iron showed that 2 out of 24 water samples were above the limit value. Results also showed the presence of manganese-oxidizing microorganisms in the drinking water distribution system. Manganese is emitted from the drinking water plant and favors microorganisms as well as increases the formation of manganese dioxide, which may cause corrosion on cast iron pipes. Thus, the composition of the drinking water can affect or accelerate corrosion in the drinking water distribution system.Theoretically, the discolorations that have been experienced by the users may be due to a high concentration of manganese. However, it cannot be excluded that discolorations may be caused by other factors as the result did not provide a statistical relationship between discoloration and the concentration of iron and manganese. Further studies are required to determine all the causes behind discoloured drinking water. The problem of the concentrations of manganese should be solved, whether or not it is the main cause of the water discoloration. The concentrations of iron and manganese are likely to increase in the raw water due to climate change. If the drinking water plant continues to mix surface and groundwater, the problem can be solved by installing a static mixer and introducing a separation step for iron and manganese. When choosing a biological separation method, microorganisms from the drinking water distribution system can be used.

The new borophosphates described here were synthesized under mild hydrothermal conditions (170 oC or 220 oC). Powder and single crystal X-ray diffraction were employed to determine and refine the crystal structures. DTA-TG methods were used to analyze the thermal stability. High temperature powder X-ray diffraction (HT-XRD) was applied to study the thermal behavior of products and identify the intermediate phase during the decomposition. Chemical analyses were performed to quantitatively determine the chemical composition. Magnetic properties of the compounds were investigated. 19F MAS NMR was used to check the number of fluorine positions in the crystal structure. The following compounds were prepared and characterized: (C2H10N2)[BPO4F2](C6H14N2){Zn[ZnB2P4O15(OH)2]¡P(C6H13N2)Cl} (zndabcocl) (C3H12N2){Mn[B2P3O12(OH)]} (DAP-Mn) and (C4H12N2){Mn[B2P3O12(OH)]} (PIP-Mn) (C3H12N2){FeIII6(H2O)4[B4P8O32(OH)8]}(C3H12N2)2{VIII2VIV3B2P8O38H8} (dapvbpo) K3[B5PO10(OH)3](C2H10N2)[BPO4F2] is the first fluorine-substituted borophosphate and the first borophosphate with crystal structure closely related to the pyroxene type structure. Unbranched zweier single chain {[BPO4F2]2?} represents a new type of borophosphate partial structure. zndabcoclrepresents the first organo-templated zincoborophosphate. The structure contains diaza-bicyclo[2.2.2]-octane (DABCO) which acts in its diprotonated form (H2DABCO)2+ as a pure template and in its monoprotonated form (HDABCO)+ as a ligand to Zn-positions at the borders of ribbons to complete structural motif. This compound is also the first example containing a quaternary Zn-tetrahedron (ZnO2NCl), and can formally be described as an adduct of (C6H14N2)Zn[ZnB2P4O15(OH)2] with diaza-bicyclo[2.2.2]octane-hydrochloride. The thermal behavior of zndabcocl has been studied by HT-XRD and DTA-TG in the temperature range 25?600 oC. The new phase occurring during the decomposition has been identified as HT-NH4[ZnBP2O8].DAP-Mnand PIP-Mn contain identical framework interconnections but difference in the shape of resulting channels, which are due to the different shape of organic templates. The crystal structures are built from the same building units: loop-branched single chains are connected via MnO6-octahedra resulting in a 3-D structure with intersecting channel systems running along [100], [011] and [01], respectively. The different shape of the template controls the shape of the channels, especially channels running along [100], resulting in dramatic shape-differences. The linear (H2DAP)2+ ions make the channels more elongated, while the cyclic (H2PIP)2+ ions give rise to more regular shaped channels. The flexibility of frameworks may be due to the more flexible coordination of Mn-atoms (octahedron and square pyramid).(C3H12N2){FeIII6(H2O)4[B4P8O32(OH)8]} is a new borophosphate with 3-D framework structure, a large size of 10-ring channel (778 ¡Ñ 867 pm2) is occupied by organic templates. The magnetic susceptibility measurements show it to exhibit antiferromagnetic susceptibility at low temperature (TN ?l 14K).dapvbpois the first mixed-valency vanadium borophosphate with a new structure type. Its structure can be considered as an ?intergrowth? of puckered vanadium(III) borophosphate layer (VIIIBPO-layer) and planar vanadium(IV) phosphate layers (VIVPO-layer) stacked and interconnected alternately along [001], which results in a new and unusual building motif. The corner sharing trimers of vanadium octahedra are observed for the first time in vanadium borophosphates. K3[B5PO10(OH)3] has a double unit cell of a twin crystal structure having the same chemical formula. The double b-axis solves the disorder problem of two oxygen positions coordinated to phosphorous. It represents a much more reasonable structure determination.

The aim of the study was to determine the influence of phenolics content and inoculation with soil extract on microbial respiration, on the phenoloxidase (PhOx), peroxidase (PerOx) and newly Mn-peroxidase (MnP) activity in two dominating litter samples (Calamagrostis villosa and Picea abies) differing in phenolics content from Plešné and Čertovo lake watersheds. At PhOx and PerOx activity, the dependence on incubation temperature with L-DOPA was estimated. PhOx and MnP activities significantly increased with higher content of hardly decomposable phenolics, but decreased with water extractable phenolics content. Inoculation with soil extract had no influence on microbial respiration, enzyme activity, nor on decomposition of phenolics. Microbial respiration was significantly higher at 10°C, but average enzyme activity was comparable at 0 and 10°C. PhOx activities had temperature optimum higher than 22°C, while PerOx activities had temperature optimum at 0 - 15°C.

Coordination complexes [M(O2CCH2OC2H4OMe)2] (M = Co, 4; M = Mn, 5) are accessible by the anion exchange reaction between the corresponding metal acetates [M(OAc)2(H2O)4] (M = Co, 1; M = Mn, 2) and the carboxylic acid HO2CCH2OC2H4OMe (3). IR spectroscopy confirms the chelating or μ-bridging binding mode of the carboxylato ligands to M(II). The molecular structure of 5 in the solid state confirms a distorted octahedral arrangement at Mn(II), setup by the two carboxylato ligands including their α-ether oxygen atoms, resulting in an overall two-dimensional coordination network. The thermal decomposition behavior of 4 and 5 was studied by TG-MS, revealing that decarboxylation occurs initially giving [M(CH2OC2H4OMe)2], which further decomposes by M–C, C–O and C–C bond cleavages. Complexes 4 and 5 were used as CCVD (combustion chemical vapour deposition) precursors for the deposition of Co3O4, crystalline Mn3O4 and amorphous Mn2O3 thin films on silicon and glass substrates. The deposition experiments were carried out using three different precursor solutions (0.4, 0.6 and 0.8 M) at 400 °C. Depending on the precursor concentration, particulated layers were obtained as evidenced by SEM. The layer thicknesses range from 32 to 170 nm. The rms roughness of the respective films was determined by AFM, displaying that the higher the precursor concentration, the rougher the Co3O4 surface is (17.4–43.8 nm), while the manganese oxide films are almost similar (6.2–9.8 nm).

The new borophosphates described here were synthesized under mild hydrothermal conditions (170 oC or 220 oC). Powder and single crystal X-ray diffraction were employed to determine and refine the crystal structures. DTA-TG methods were used to analyze the thermal stability. High temperature powder X-ray diffraction (HT-XRD) was applied to study the thermal behavior of products and identify the intermediate phase during the decomposition. Chemical analyses were performed to quantitatively determine the chemical composition. Magnetic properties of the compounds were investigated. 19F MAS NMR was used to check the number of fluorine positions in the crystal structure. The following compounds were prepared and characterized: (C2H10N2)[BPO4F2](C6H14N2){Zn[ZnB2P4O15(OH)2]¡P(C6H13N2)Cl} (zndabcocl) (C3H12N2){Mn[B2P3O12(OH)]} (DAP-Mn) and (C4H12N2){Mn[B2P3O12(OH)]} (PIP-Mn) (C3H12N2){FeIII6(H2O)4[B4P8O32(OH)8]}(C3H12N2)2{VIII2VIV3B2P8O38H8} (dapvbpo) K3[B5PO10(OH)3](C2H10N2)[BPO4F2] is the first fluorine-substituted borophosphate and the first borophosphate with crystal structure closely related to the pyroxene type structure. Unbranched zweier single chain {[BPO4F2]2?} represents a new type of borophosphate partial structure. zndabcoclrepresents the first organo-templated zincoborophosphate. The structure contains diaza-bicyclo[2.2.2]-octane (DABCO) which acts in its diprotonated form (H2DABCO)2+ as a pure template and in its monoprotonated form (HDABCO)+ as a ligand to Zn-positions at the borders of ribbons to complete structural motif. This compound is also the first example containing a quaternary Zn-tetrahedron (ZnO2NCl), and can formally be described as an adduct of (C6H14N2)Zn[ZnB2P4O15(OH)2] with diaza-bicyclo[2.2.2]octane-hydrochloride. The thermal behavior of zndabcocl has been studied by HT-XRD and DTA-TG in the temperature range 25?600 oC. The new phase occurring during the decomposition has been identified as HT-NH4[ZnBP2O8].DAP-Mnand PIP-Mn contain identical framework interconnections but difference in the shape of resulting channels, which are due to the different shape of organic templates. The crystal structures are built from the same building units: loop-branched single chains are connected via MnO6-octahedra resulting in a 3-D structure with intersecting channel systems running along [100], [011] and [01], respectively. The different shape of the template controls the shape of the channels, especially channels running along [100], resulting in dramatic shape-differences. The linear (H2DAP)2+ ions make the channels more elongated, while the cyclic (H2PIP)2+ ions give rise to more regular shaped channels. The flexibility of frameworks may be due to the more flexible coordination of Mn-atoms (octahedron and square pyramid).(C3H12N2){FeIII6(H2O)4[B4P8O32(OH)8]} is a new borophosphate with 3-D framework structure, a large size of 10-ring channel (778 ¡Ñ 867 pm2) is occupied by organic templates. The magnetic susceptibility measurements show it to exhibit antiferromagnetic susceptibility at low temperature (TN ?l 14K).dapvbpois the first mixed-valency vanadium borophosphate with a new structure type. Its structure can be considered as an ?intergrowth? of puckered vanadium(III) borophosphate layer (VIIIBPO-layer) and planar vanadium(IV) phosphate layers (VIVPO-layer) stacked and interconnected alternately along [001], which results in a new and unusual building motif. The corner sharing trimers of vanadium octahedra are observed for the first time in vanadium borophosphates. K3[B5PO10(OH)3] has a double unit cell of a twin crystal structure having the same chemical formula. The double b-axis solves the disorder problem of two oxygen positions coordinated to phosphorous. It represents a much more reasonable structure determination.

PsbO (manganese-stabilizing protein) is the largest extrinsic protein of photosystem II, located on the lumen side of photosystem. It is present in all known oxyphototrophic organisms. PsbO facilitates photosynthetic water splitting, which takes place in an oxygen evolving center (Mn4CaO5 cluster) of photosystem II. This work is focused on PsbO of higher plants and its isoforms, particularly their evolution and functions. Bioinformatic analyses revealed that majority of higher plants express exactly two psbO isoforms. A phylogenetic tree of PsbO sequences has an unusual topology. The two paralogous isoforms do not diverge at the base of the phylogenetic tree, as anticipated, but rather at the end of particular branches, at the level of family or lower taxonomic unit. In this work we propose and discuss several hypotheses concerning evolution of PsbO isoforms. The work further includes detailed analysis and identification of protein spots assigned to PsbO on 2D IEF-SDS PAGE gels of potato thylakoid proteins. We identified predominant version of PsbO isoform in most of the spots. We did not succeed to find any posttranslational modification. We optimized a method of psbO expression in E. coli and subsequent purification, which yielded relatively big amount of properly folded recombinant protein. Analysis of...

Made available in DSpace on 2014-12-17T15:41:59Z (GMT). No. of bitstreams: 1 Mariele ISM_DISSERT.pdf: 4704397 bytes, checksum: 9fa1538bc3d6948d492f9a6c378eaf62 (MD5) Previous issue date: 2012-07-20 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Processo de Dessulfuriza??o Oxidativa (ODS) de um diesel comercial foi realizado em condi??es suaves na presen?a de catalisadores a base de van?dio ou mangan?s, suportados em aluminas, argilas e ze?litas. A oxida??o e extra??o da mol?cula de dibenzotiofeno (DBT), representando os compostos de enxofre presentes no diesel, foram realizadas usando como solvente a acetonitrila e oxidante o per?xido de hidrog?nio a temperatura de 55?C. O processo mostrou-se eficiente, o DBT foi convertido para sua respectiva sulfona, e a quantidade que n?o foi convertida a sulfona foi extra?da pelo solvente. O sistema de rea??o apresentou remo??o e oxida??o de at? 100% do composto de enxofre com alguns catalisadores. Verificando que para a oxida??o os catalisadores foram mais ativos, e os catalisadores de mangan?s apresentaram melhores resultados na extra??o dos compostos de enxofre.