Studies on metal complex formation of environmentally friendly aminopolycarboxylate chelating agents

Aminopolykarboksyylaatteja, kuten etyleenidiamiinitetraetikkahappoa (EDTA), on käytetty useiden vuosikymmenien ajan erinomaisen metalli-ionien sitomiskyvyn vuoksi kelatointiaineena lukuisissa sovelluksissa sekä analytiikassa että monilla teollisisuuden aloilla. Näiden yhdisteiden biohajoamattomuus on kuitenkin herättänyt huolta viime aikoina, sillä niiden on havaittu olevan hyvin pysyviä luonnossa. Tämä työ on osa laajempaa tutkimushanketta, jossa on tavoitteena löytää korvaavia kelatointiaineita EDTA:lle. Tutkimuksen aiheena on kuuden kelatointiaineen metalli-ionien sitomiskyvyn kartoitus. EDTA:a paremmin luonnossa hajoavina nämä ovat ympäristöystävällisiä ehdokkaita korvaaviksi kelatointiaineiksi useisiin sovelluksiin. Työssä tutkittiin niiden kompleksinmuodostusta useiden metalli-ionien kanssa potentiometrisella titrauksella. Metalli-ionivalikoima vaihteli hieman kelatointiaineesta riippuen sisältäen magnesium-, kalsium-, mangaani-, rauta-, kupari-, sinkki-, kadmium-, elohopea-, lyijy- ja lantaani-ionit. Tutkittavat metallit oli valittu tähtäimessä olevien sovellusten, synteesissä ilmenneiden ongelmien tai ympäristönäkökohtien perusteella. Tulokset osoittavat näiden yhdisteiden metallinsitomiskyvyn olevan jonkin verran heikompi kuin EDTA:lla, mutta kuitenkin riittävän useisiin sovelluksiin kuten sellunvalkaisuprosessiin. Myrkyllisten raskasmetallien, kadmiumin, elohopen ja lyijyn kohdalla EDTA:a heikompi sitoutuminen on eduksikin, koska se yhdistettynä parempaan biohajoavuuteen saattaa alentaa tutkittujen yhdisteiden kykyä mobilisoida kyseisiä metalleja sedimenteistä. Useimmilla tutkituista yhdisteistä on ympäristönäkökulmasta etuna myös EDTA:a pienempi typpipitoisuus.

Levosimendaanin vaikutusmekanismi ja nykyinen merkitys sydämen vajaatoiminnan hoidossa

Sydämen vajaatoiminta on erilaisista sydän- ja verisuonisairauksista aiheutuva monimuotoinen oireyhtymä, johon sairastuneiden ja kuolleiden potilaiden määrä on yhä suuri. Sen patofysiologiaan voi kuulua muun muassa sympaattisen hermoston ja reniini-angiotensiini-aldosteroni–järjestelmän aktiivisuutta, huonosti supistuva vasen kammio, sydämen uudelleenmuokkautumista, muutoksia [Ca2+]i:n säätelyssä, kardiomyosyyttien apoptoosia sekä systeeminen tulehdustila. Johonkin osaan sairauden patofysiologiasta eivät nykyiset lääkehoidot riittävästi vaikuta. Klassiset inotroopit lisäävät sydämen supistusvireyttä kasvattamalla solunsisäistä Ca2+-pitoisuutta, mutta ne lisäävät rytmihäiriöriskiä, sydämen hapenkulutusta sekä heikentävät ennustetta. Levosimendaani, kalsiumherkistäjä, lisää sydämen supistusvoimaa [Ca2+]i:ta kohottamatta herkistämällä sydänlihaksen kalsiumin vaikutuksille. Lisäksi levosimendaani avaa sarkolemmaalisia ja mitokondriaalisia K+-kanavia, jotka välittävät vasodilataatiota ja kardioprotektiota. Suurilla annoksilla levosimendaani on selektiivinen PDE3-estäjä. Levosimendaania suositellaan äkillisesti pahentuneen sydämen vajaatoiminnan hoitoon, mutta muitakin lupaavia indikaatioita sille on keksitty. Esimerkiksi kroonisesti annosteltu oraalinen levosimendaani on suojannut kardiovaskulaarijärjestelmää ja parantanut selviytymistä in vivo. Erikoistyössä selvitettiin kroonisesti annostellun oraalisen levosimendaanin, valsartaanin ja näiden kombinaatioterapian vaikutuksia selviytymiseen, verenpaineeseen sekä sydämen hypertrofioitumiseen Dahlin suolaherkillä (Dahl/Rapp) rotilla. Levosimendaanin suojavaikutus ilmeni vähäisempänä kuolleisuutena, mutta ero ei ollut tilastollisesti merkitsevä kontrolliryhmään nähden. Kombinaatioterapia suojasi rottia kardiovaskulaarikuolleisuudelta ja vähensi todennäköisesti verenpaineesta riippuvaisesti sydämen hypertofioitumista niin sydän/kehonpaino–suhteen kuin ultraäänitutkimuksenkin perusteella arvioituna paremmin kuin kumpikaan lääke monoterapiana. Lääkekombinaatio alensi additiivisesti hypertensiota kaikissa mittauspisteissä. Sydämen systolista toimintaa levosimendaani kohensi vain vähäisesti. Dahl/Rapp-rotille kehittyikin pääosin hypertension indusoimaa diastolista sydämen vajaatoimintaa kohonneen IVRT-arvon perusteella. Levosimendaani sekä monoterapiana että kombinaatioterapiana valsartaanin kanssa vähensi sydämen diastolista vajaatoimintaa.

Nitrogen dynamics and nitrogen use efficiency of spring cereals under Finnish growing conditions

Nitrogen (N) is one of the main inputs in cereal cultivation and as more than half of the arable land in Finland is used for cereal production, N has contributed substantially to agricultural pollution through fertilizer leaching and runoff. Based on this global phenomenon, the European Community has launched several directives to reduce agricultural emissions to the environment. Trough such measures, and by using economic incentives, it is expected that northern European agricultural practices will, in the future, include reduced N fertilizer application rates. Reduced use of N fertilizer is likely to decrease both production costs and pollution, but could also result in reduced yields and quality if crops experience temporary N deficiency. Therefore, more efficient N use in cereal production, to minimize pollution risks and maximize farmer income, represents a current challenge for agronomic research in the northern growing areas. The main objective of this study was to determine the differences in nitrogen use efficiency (NUE) among spring cereals grown in Finland. Additional aims were to characterize the multiple roles of NUE by analysing the extent of variation in NUE and its component traits among different cultivars, and to understand how other physiological traits, especially radiation use efficiency (RUE) and light interception, affect and interact with the main components of NUE and contribute to differences among cultivars. This study included cultivars of barley (Hordeum vulgare L.), oat (Avena sativa L.) and wheat (Triticum aestivum L.). Field experiments were conducted between 2001 and 2004 at Jokioinen, in Finland. To determine differences in NUE among cultivars and gauge the achievements of plant breeding in NUE, 17-18 cultivars of each of the three cereal species released between 1909 and 2002 were studied. Responses to nitrogen of landraces, old cultivars and modern cultivars of each cereal species were evaluated under two N regimes (0 and 90 kg N ha-1). Results of the study revealed that modern wheat, oat and barley cultivars had similar NUE values under Finnish growing conditions and only results from a wider range of cultivars indicated that wheat cultivars could have lower NUE than the other species. There was a clear relationship between nitrogen uptake efficiency (UPE) and NUE in all species whereas nitrogen utilization efficiency (UTE) had a strong positive relationship with NUE only for oat. UTE was clearly lower in wheat than in other species. Other traits related to N translocation indicated that wheat also had a lower harvest index, nitrogen harvest index and nitrogen remobilisation efficiency and therefore its N translocation efficiency was confirmed to be very low. On the basis of these results there appears to be potential and also a need for improvement in NUE. These results may help understand the underlying physiological differences in NUE and could help to identify alternative production options, such as the different roles that species can play in crop rotations designed to meet the demands of modern agricultural practices.

Diet, cell signalling, and tumourigenesis in multiple intestinal neoplasia mice

The incidence of colon cancer is high in Western societies, and in Finland it is among the three most common cancer types in both females and males. Environmental factors, including diet, affect colon cancer development. During the last few years, a vast amount of new, functional foods have been introduced to the consumers. Several products are already available that are marketed as promoting intestinal health. To be able to reliably call a dietary compound a chemopreventive substance it is of fundamental importance to understand the mechanism by which it affects tumour formation and the integrity of the epithelial cells. In this thesis, three different dietary compounds were studied in an experimental model of colon cancer. Inulin is a non-digestible fibre found naturally in chicory roots, artichokes and onions, amongst others. Nowadays it is widely used as an added dietary fibre in several food products. Conjugated linoleic acid (CLA) is a conjugated form of the fatty acid linoleic acid. CLA is formed by bacterial fermentation of linoleic acid in the rumen of cows and other ruminants. Concomitantly, it can naturally be found in milk and meat of ruminants. White currant is a colourless berry low in phenolic compounds that are believed to prevent cancer formation. Contrary to what was expected, inulin and the conjugated linoleic acid isomer trans-10, cis-12, were tumour growth promoting dietary constituents when fed to Min mice. Both diets decreased the NF-kappaB levels in the mucosa, but physiological adenoma development did not affect NF-kappaB. Diet altered beta-catenin and p53 signalling in the adenomas, confirming their involvement in adenoma growth. White currant, on the other hand, was chemopreventive, despite its low contents of phenolic compounds. The chemopreventive effect was accompanied by increased p53 levels in the mucosa, and decreased beta-catenin and NF-kappaB levels in the adenoma. This could explain the reduced adenoma number and size. The results underline the importance of carefully testing new dietary compounds in different settings to reliably confirm their health benefits. In this study two compounds that are consumed and believed to add to our health proved to be cancer promotive. A berry with low phenolic contents, on the other hand, was chemopreventive.

Plant secondary compounds and soil microbial processes in carbon and nitrogen cycling in relation to tree species

The aim of this study was to explore soil microbial activities related to C and N cycling and the occurrence and concentrations of two important groups of plant secondary compounds, terpenes and phenolic compounds, under silver birch (Betula pendula Roth), Norway spruce (Picea abies (L.) Karst) and Scots pine (Pinus sylvestris L.) as well as to study the effects of volatile monoterpenes and tannins on soil microbial activities. The study site, located in Kivalo, northern Finland, included ca. 70-year-old adjacent stands dominated by silver birch, Norway spruce and Scots pine. Originally the soil was very probably similar in all three stands. All forest floor layers (litter (L), fermentation layer (F) and humified layer (H)) under birch and spruce showed higher rates of CO2 production, greater net mineralisation of nitrogen and higher amounts of carbon and nitrogen in microbial biomass than did the forest floor layers under pine. Concentrations of mono-, sesqui-, di- and triterpenes were higher under both conifers than under birch, while the concentration of total water-soluble phenolic compounds as well as the concentration of condensed tannins tended to be higher or at least as high under spruce as under birch or pine. In general, differences between tree species in soil microbial activities and in concentrations of secondary compounds were smaller in the H layer than in the upper layers. The rate of CO2 production and the amount of carbon in the microbial biomass correlated highly positively with the concentration of total water-soluble phenolic compounds and positively with the concentration of condensed tannins. Exposure of soil to volatile monoterpenes and tannins extracted and fractionated from spruce and pine needles affected carbon and nitrogen transformations in soil, but the effects were dependent on the compound and its molecular structure. Monoterpenes decreased net mineralisation of nitrogen and probably had a toxic effect on part of the microbial population in soil, while another part of the microbes seemed to be able to use monoterpenes as a carbon source. With tannins, low-molecular-weight compounds (also compounds other than tannins) increased soil CO2 production and nitrogen immobilisation by soil microbes while the higher-molecular-weight condensed tannins had inhibitory effects. In conclusion, plant secondary compounds may have a great potential in regulation of C and N transformations in forest soils, but the real magnitude of their significance in soil processes is impossible to estimate.

Diet and the development of atherosclerosis: a whole-diet approach from childhood to adulthood

Cardiovascular diseases (CVDs) are the leading cause of mortality in the world. Studies of the impact of single nutrients on the risk for CVD have often provided inconclusive results, and recent research in nutritional epidemiology with a more holistic whole-diet approach has proven fruitful. Moreover, dietary habits in childhood and adolescence may play a role in later health and disease, either independently or by tracking into adulthood. The main aims of this study were to find childhood and adulthood determinants of adulthood diet, to identify dietary patterns present among the study population and to study the associations between long-term food choices and cardiovascular health in young Finnish adults. The study is a part of the multidisciplinary Cardiovascular Risk in Young Finns study, which is an ongoing, prospective cohort study with a 21-year follow-up. At baseline in 1980, the subjects were children and adolescents aged 3 to 18 years (n included in this study = 1768), and young adults aged 24 to 39 years at the latest follow-up study in 2001 (n = 1037). Food consumption and nutrient intakes were assessed with repeated 48-hour dietary recalls. Other determinations have included comprehensive risk factor assessments using blood tests, physical measurements and questionnaires. In the latest follow-up, ultrasound examinations were performed to study early atherosclerotic vascular changes. The average intakes showed substantial changes since 1980. Intakes of fat and saturated fat had decreased, whereas the consumption of fruits and vegetables had increased. Intake of fat and consumption of vegetables in childhood and physical activity in adulthood were important health behavioural determinants of adult diet. Additionally, a principal component analysis was conducted to identify major dietary patterns at each study point. A similar set of two major patterns was recognised throughout the study. The traditional dietary pattern positively correlated with the consumption of traditional Finnish foods, such as rye, potatoes, milk, butter, sausages and coffee, and negatively correlated with fruit, berries and dairy products other than milk. This type of diet was independently associated with several risk factors of CVD, such as total and low-density lipoprotein cholesterol, apolipoprotein B and C-reactive protein concentrations among both genders, as well as with systolic blood pressure and insulin levels among women. The traditional pattern was also independently associated with intima media thickness (IMT), a subclinical predictor of CVD, in men but not in women. The health-conscious pattern, predominant among female subjects, non-smokers and urbanites, was characterised by more health-conscious food choices such as vegetables, legumes and nuts, tea, rye, fish, cheese and other dairy products, as well as by the consumption of alcoholic beverages. This pattern was inversely, but less strongly, associated with cardiovascular risk factors. Tracking of the dietary pattern scores was observed, particularly among subjects who were adolescents at baseline. Moreover, a long-term high intake of protein concurrent with a low intake of fat was positively associated with IMT. These findings suggest that food behaviour and food choices are to some extent established as early as in childhood or adolescence and may significantly track into adulthood. Long-term adherence to traditional food choices seems to increase the risk for developing CVD, especially among men. Those with intentional or unintentional low fat diets, but with high intake of protein may also be at increased risk for CVD. The findings offer practical, food-based information on the relationship between diet and CVD and encourage further use of the whole-diet approach in epidemiological research. The results support earlier findings that long-term food choices play a role in the development of CVD. The apparent influence of childhood habits is important to bear in mind when planning educational strategies for the primary prevention of CVD. Further studies on food choices over the entire lifespan are needed.

Ammonia emissions from pig and cattle slurry in the field and utilization of slurry nitrogen in crop production

Volatilization of ammonia (NH3) from animal manure is a major pathway for nitrogen (N) losses that cause eutrophication, acidification, and other environmental hazards. In this study, the effect of alternative techniques of manure treatment (aeration, separation, addition of peat) and application (broadcast spreading, band spreading, injection, incorporation by harrowing) on ammonia emissions in the field and on nitrogen uptake by ley or cereals was studied. The effect of a mixture of slurry and peat on soil properties was also investigated. The aim of this study was to find ways to improve the utilization of manure nitrogen and reduce its release to the environment. Injection into the soil or incorporation by harrowing clearly reduced ammonia volatilization from slurry more than did the surface application onto a smaller area by band spreading or reduction of the dry matter of slurry by aeration or separation. Surface application showed low ammonia volatilization, when pig slurry was applied to tilled bare clay soil or to spring wheat stands in early growth stages. Apparently, the properties of both slurry and soil enabled the rapid infiltration and absorption of slurry and its ammoniacal nitrogen by the soil. On ley, however, surface-applied cattle slurry lost about half of its ammoniacal nitrogen. The volatilization of ammonia from surface-applied peat manure was slow, but proceeded over a long period of time. After rain or irrigation, the peat manure layer on the soil surface retarded evaporation. Incorporation was less important for the fertilizer effect of peat manure than for pig slurry, but both manures were more effective when incorporated. Peat manure applications increase soil organic matter content and aggregate stability. Stubble mulch tillage hastens the effect in surface soil compared with ploughing. The apparent recovery of ammoniacal manure nitrogen in crop yield was higher with injection and incorporation than with surface applications. This was the case for leys as well as for spring cereals, even though ammonia losses from manures applied to cereals were relatively low with surface applications as well. The ammoniacal nitrogen of surface-applied slurry was obviously adsorbed by the very surface soil and remained mostly unavailable to plant roots in the dry soil. Supplementing manures with inorganic fertilizer nitrogen, which adds plant-available nitrogen to the soil at the start of growth, increased the overall recovery of applied nitrogen in crop yields.

Nitrogen dynamics of organic farming in a crop rotation based on red clover (Trifolium pratense) leys

In agricultural systems which rely on organic sources of nitrogen (N), of which the primary source is biological N fixation (BNF), it is extremely important to use N as efficiently as possible with minimal losses to the environment. The amount of N through BNF should be maximised and the availability of the residual N after legumes should be synchronised to the subsequent plant needs in the crop rotation. Six field experiments in three locations in Finland were conducted in 1994-2006 to determine the productivity and amount of BNF in red clover-grass leys of different ages. The residual effects of the leys for subsequent cereals as well as the N leaching risk were studied by field measurements and by simulation using the CoupModel. N use efficiency (NUE) and N balances were also calculated. The yields of red clover-grass leys were highest in the two-year-old leys (6 700 kg ha-1) under study, but the differences between 2- and 3-year old leys were not high in most cases. BNF (90 kg ha-1 in harvested biomass) correlated strongly with red clover dry matter yield, as the proportion of red clover N derived from the atmosphere (> 85%) was high in our conditions of organically farmed field with low soil mineral N. A red clover content of over 40% in dry matter is targeted to avoid negative N-balances and to gain N for the subsequent crop. Surprisingly, the leys had no significant effect on the yields and N uptake of the two subsequent cereals (winter rye or spring wheat, followed by spring oats). On the other hand, yield and C:N of leys, as well as BNF-N and total-N incorporated into the soil influenced on subsequent cereal yields. NUE of cereals from incorporated ley crop residues was rather high, varying from 30% to 80% (mean 48%). The mineral N content of soil in the profile of 0-90 cm was low, mainly 15-30 kg ha-1. Simulation of N dynamics by CoupModel functioned satisfactorily and is considered a useful tool to estimate N flows in cropping systems relying on organic N sources. Understanding the long-term influence of cultivation history and soil properties on N dynamics remains to be a challenge to further research.

Polymerization of Ethene and Branched α-olefins with Group IV Metal Complexes Bearing Nitrogen- and Oxygen-Based Ligands

The commodity plastics that are used in our everyday lives are based on polyolefin resins and they find wide variety of applications in several areas. Most of the production is carried out in catalyzed low pressure processes. As a consequence polymerization of ethene and α-olefins has been one of the focus areas for catalyst research both in industry and academia. Enormous amount of effort have been dedicated to fine tune the processes and to obtain better control of the polymerization and to produce tailored polymer structures The literature review of the thesis concentrates on the use of Group IV metal complexes as catalysts for polymerization of ethene and branched α-olefins. More precisely the review is focused on the use of complexes bearing [O,O] and [O,N] type ligands which have gained considerable interest. Effects of the ligand framework as well as mechanical and fluxional behaviour of the complexes are discussed. The experimental part consists mainly of development of new Group IV metal complexes bearing [O,O] and [O,N] ligands and their use as catalysts precursors in ethene polymerization. Part of the experimental work deals with usage of high-throughput techniques in tailoring properties of new polymer materials which are synthesized using Group IV complexes as catalysts. It is known that the by changing the steric and electronic properties of the ligand framework it is possible to fine tune the catalyst and to gain control over the polymerization reaction. This is why in this thesis the complex structures were designed so that the ligand frameworks could be fairly easily modified. All together 14 complexes were synthesised and used as catalysts in ethene polymerizations. It was found that the ligand framework did have an impact within the studied catalyst families. The activities of the catalysts were affected by the changes in complex structure and also effects on the produced polymers were observed: molecular weights and molecular weight distributions were depended on the used catalyst structure. Some catalysts also produced bi- or multi-modal polymers. During last decade high-throughput techniques developed in pharmaceutical industries have been adopted into polyolefin research in order to speed-up and optimize the catalyst candidates. These methods can now be regarded as established method suitable for both academia and industry alike. These high-throughput techniques were used in tailoring poly(4-methyl-1-pentene) polymers which were synthesized using Group IV metal complexes as catalysts. This work done in this thesis represents the first successful example where the high-throughput synthesis techniques are combined with high-throughput mechanical testing techniques to speed-up the discovery process for new polymer materials.

Mycorrhizal fungi and nitrogen dynamics in drained peatland

Fungi have a fundamental role in carbon and nutrient transformations in the acids soils of boreal regions, such as peatlands, where high amounts of carbon (C) and nutrients are stored in peat, the pH is relatively low and the nutrient uptake of trees is highly dependent on mycorrhizae. In this thesis, the aim was to examine nitrogen (N) transformations and the availability of dissolved N compounds in forestry-drained peatlands, to compare the fungal community biomass and structure at various peat N levels, to investigate the growth of ectomycorrhizal fungi with variable P and K availability and to assess how the ectomycorrhizal fungi (ECM) affect N transformations. Both field and laboratory experiments were carried out. The peat N concentration did not affect the soil fungal community structure within a site. Phosphorus (P) and potassium (K) deficiency of the trees as well as the degree of decomposition and dissolved organic nitrogen (DON) concentration of the peat were shown to affect the fungal community structure and biomass of ECMs, highlighting the complexity of the below ground system on drained peatlands. The biomass of extrametrical mycorrhizal mycelia (EMM) was enhanced by P and/or K deficiency of the trees, and ECM biomass in the roots was increased by P deficiency. Thus, PK deficiency in drained peatlands may increase the allocation of C by the tree to ECMs. It was also observed that fungi can alter N mineralization processes in the rhizosphere but variously depending on fungal species and fertility level of peat. Gross N mineralization did not vary but the net N mineralization rate significantly increased along the N gradient in both field and laboratory experiments. Gross N immobilization also significantly increased when the peat N concentration increased. Nitrification was hardly detectable in either field or laboratory experiments. During the growing season, dissolved inorganic N (DIN) fluctuated much more than the relatively stable DON. Special methodological challenges associated with sampling and analysis in microbial studies on peatlands are discussed.

Aspergillus niger -proliiniendopeptidaasi prolamiinien eliminoinnissa

Tutkielman kirjallisuusosassa perehdyttiin vehnän, rukiin ja ohran, eli Triticeaeprolamiinien erityisasemaan keliakianäkökulmasta tarkasteltuna ja prolamiinien hydrolyysiin proliinispesifeillä entsyymeillä. Lisäksi tarkasteltiin prolamiinien immunologisia määritysmenetelmiä. Keliakiassa haitalliset gluteenipeptidit sisältävät runsaasti proliinia ja ovat hankalia pilkkoa muilla kuin proliinispesifeillä peptidaaseilla. Suurin osa immunologisen reaktion aiheuttavista gluteenilähtöisistä peptideistä voidaan pilkkoa idätetyn viljan endogeenisilla entsyymeillä happamissa olosuhteissa, mutta jäljellejäävä prolamiinipitoisuus ylittää edelleen gluteenittomille tuotteille sallitun rajan. Kokeellisen työn tavoitteena oli eliminoida happamalla mallasinkubaatiolla valmistettujen vehnä-, ohra- ja ruismallasautolysaattien sisältämä jäännösprolamiini Aspergillus niger -homeen tuottamalla proliinispesifillä endopeptidaasilla (AN-PEP) siten, että hydrolysaattia voitaisiin käyttää gluteenittomissa leivontasovelluksissa. Proteiinien hydrolyysiä tarkkailtiin kokoekskluusiokromatografialla (SEC), vapaan aminotypen (FAN) muodostumisena ja SDS-PAGE-elektroforeesilla. Jäännösprolamiinien pilkkoutumista seurattiin immunologisella R5-ELISA-menetelmällä. AN-PEP-inkubaatiolla saatiin aikaan voimakasta prolamiinien pilkkoutumista; mallasautolysaattien jäännösprolamiinista pilkkoutui yli 96 %. SEC- ja FAN-analyysien perusteella inkubaatioaikaa kannatti jatkaa yli 4 h, jolloin polypeptidit pilkkoutuivat edelleen pienemmiksi hydrolyysituotteiksi. Vehnä- ja ruismallashydrolysaattien prolamiinipitoisuuden todettiin laskevan 22 h inkubaation aikana alle tason 100 mg/kg R5-ELISA-menetelmällä määritettynä. Matalimmat prolamiinipitoisuudet saavutettiin AN-PEP-pitoisuudella 35 ?l / g mallasautolysaattia. Codex Alimentarius -komission säädöksen mukaan keliakiaruokavalioon soveltuvat ns. erittäin vähägluteeniset tuotteet saavat sisältää gluteenia enintään 100 mg/kg. Erityisesti AN-PEP-käsiteltyä ruismallasraaka-ainetta voitaisiin mahdollisesti käyttää tuomaan rukiista aromia gluteenittomiin leipiin. Ennen kuin mallashydrolysaatit ovat valmiita kaupallisiin sovelluksiin, on tarkasteltava niiden todellisia mahdollisuuksia parantaa elintarvikkeiden makua ja aromia sekä todettava uuden teknologian turvallisuus keliaakikoille.

The roles of nitrification and nitrate reduction pathways in nitrogen cycling of Baltic Sea

The Baltic Sea is one of the largest brackish water bodies in the world. Primary production in the Baltic Sea is limited by nitrogen (N) availability with the exception of river outlets and the northernmost phosphorus limited basin. The excess human induced N load from the drainage basin has caused severe eutrophication of the sea. The excess N loads can be mitigated by microbe mediated natural N removal processes that are found in the oxic-anoxic interfaces in sediments and water column redoxclines. Such interfaces allow the close coupling between the oxic nitrification process, and anoxic denitrification and anaerobic ammonium oxidation (anammox) processes that lead to the formation of molecular nitrogen gas. These processes are governed by various environmental parameters. The effects of these parameters on N processes were investigated in the northern Baltic Sea sediments. During summer months when the sediment organic content is at its highest, nitrification and denitrification reach their maximum rates. However, nitrification had no excess potential, which was probably because of high competition for molecular oxygen (O2) between heterotrophic and nitrification microbes. Subsequently, the limited nitrate (NO3-) availability inhibited denitrification. In fall, winter and spring, nitrification was limited by ammonium availability and denitrification limited by the availability of organic carbon and occasionally by NO3-. Anaerobic ammonium oxidation (anammox) was not an important N removal process in the northern Baltic Sea. Modeling studies suggest that when hypoxia expands in the Baltic Sea, N removal intensifies. However, the results of this study suggest the opposite because bottom water hypoxia (O2< 2 ml l-1) decreased the denitrification rates in sediments. Moreover, N was recycled by the dissimilatory nitrate reduction to ammonium (DNRA) process instead of being removed from the water ecosystem. High N removal potentials were found in the anoxic water column in the deep basins of the Baltic Proper. However, the N removal in the water column appeared to be limited by low substrate availability, because the water at the depths at which the substrate producing nitrification process occurred, rarely mix with the water at the depths at which N removal processes were found. Overall, the natural N removal capacity of the northern Baltic Sea decreased compared to values measured in mid 1990s and early 2000. The reason for this appears to be increasing hypoxia.