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  • Kiurusalmi, Mirja K (Helsingin yliopisto, 2015)
    Beta-glucan ((1-3),(1-4)-?-D-glucan) is a soluble cell wall polysachharide in the starchy endosperm and aleurone layer of cereal grains. It is able to form the viscose solution at low concentrations and it can form gels under certain conditions. The literature review focused on physicochemical properties of beta-glucan. Especially gelling properties and influencing contributors for gelling were discussed. Aim of the experimental studies was to study effects of different solubilization temperatures on solution properties of barley beta-glucan. Furthermore, alteration on structuring properties of beta-glucan during the storage was observed. The study explored how beta-glucan behaves in water solution and does it has a gelling properties at low concentration. In this study pure barley beta-glucan (Megazyme, 99,5 %) (concentration 1 % v/w) was solubilized in water at three different temperatures (37, 60 ja 85 °C). Samples were stored at room temperature (+21 °C) and in the cold (+5 °C) for one week. Viscoelastic properties of the samples were measured by the dynamic rhelogical measurement with two different probes. Samples were treated with calcofluor-reagent and imaged by fluorescencemicroscopy. Furthemore, photographs were taken in three or four different dates during the storage time. Structure forming and gelling properties of pure barley beta-glucan differed among the samples when different solubilization temperatures were used. The pure barley beta-glucan was partly solubilized and formed opaque and smooth gel-like structure when 60 °C solubilizing temperature were used. Fluorescence microscopy showed that many unsolubilized particles were remained in both room and cold stored 60 °C samples. Unsolubilized particles formed rapidly continuous network structures during storage, especially in cold stored sample. Both 60 °C samples showed viscoelastic behavior and had weak gel properties which were observed by dynamic rheological measurement. Sample which was solubilized at 37 °C had part of structures gel-like after storage. Large unsolubilized particles were observed in 37 °C sample after solubilization which was also revealed by fluorescence microscopy. Sample which was solubilized at 85 °C was well-dissolved and formed clear solution. In 85 °C sample were few and small particles and gel-like structure did not formed during storage. However, formation of particle clusters was observed by fluorescence microscopy in all samples with particle sizes and structures increasing after storage one week. The results of this study indicated that solubilization and storage temperatures effected on forming particles and structures of pure barley beta-glucan during storage. This study showed that solubilization temperature effected on gelling properties of pure barley beta-glucan at low concetration.
  • Syvähuoko, Jenna (Helsingin yliopisto, 2015)
    The literature review focused on the chemical properties of Fusarium mycotoxins and their masked forms, analytical methods for their determination and the toxicological and legislative aspects. In the experimental study, a multi-method was developed and validated for the simultaneous quantification of several Fusarium toxins and their masked forms in barley, oats and wheat using liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique. The simple “dilute-and-shoot” sample preparation procedure was applied, where the extraction was performed with a mixture of acetonitrile, water and acetic acid (79:20:1, v/v/v). Moreover, the aim was to obtain new data on the occurrence of the masked mycotoxins in barley, oats and wheat by analysing 95 cereal grain samples. The type A trichothecenes T-2 and HT-2 toxins (T-2 and HT-2) and the type B trichothecenes deoxynivalenol (DON) and nivalenol (NIV) as well as zearalenone (ZEN), together with 11 masked forms of them, were included based on their importance for the food safety in northern Europe. The analytes were separated on a reversed-phase column and detected in selected reaction monitoring (SRM) mode. Better peak shapes for the early eluting compounds and shorter analysis time were obtained with acetonitrile than methanol as the organic phase, thus it was chosen for the method. The method was validated according to the criteria set in the legislation. The limits of quantification varied from 0.3 to 15.9 ?g/kg. The recoveries were 92?115%, thus being within the tolerable ranges established in the legislation. The inter-day precisions (4?27%) were under the maximum permissible values. Therefore, the method proved to fit for the purpose. In this study, occurrence data on the masked mycotoxins in Finland were obtained for the first time. The presence of ZEN-16-glucoside (ZEN-16-G) and NIV-3-glucoside (NIV-3-G) were reported for the first time worldwide in some of the cereals. The most frequently found toxins were DON, NIV and HT-2. All of the masked mycotoxins included in the method were determined, the most common being DON-3-glucoside (DON-3-G), HT-2-glucoside (HT-2-G) and NIV-3-G.
  • Piili Noora (Helsingin yliopisto, 2015)
    Tämän pro gradu- tutkielman tarkoituksena on tehdä selvitys erilaisista investointilaskentamenetelmistä ja erityisesti reaalioptiomenetelmästä ja sen käytöstä maitotilan tuotantorakennusinvestoinnin riskien hinnoittelussa. Teoriaosuus koostuu investointilaskennan menetelmien esittelystä kirjallisuuden pohjalta. Tutkielman empiirisessä osuudessa tehdään katelaskelma esimerkkitilalle ja MTK:n Tyyppinavetta-hankkeen esimerkkien avulla määritetään maitotilan tuotantorakennuksen rakentamiskustannukset. Riskeiksi investoinnille, reaalioptiomenetelmää varten, määritetään maidon tuottajahinnan taso ja vaihtelu. Tuottajahintojen tarkasteluajanjakso on 1/2012 - 12/2014. Esimerkkilaskenta suoritetaan reaalioptiomenetelmää käyttämällä ja muuta-malla eri maidon tuottajahintatasolla, tuottajahinnan vaihtelusta määritetyllä epävarmuusprosentilla sekä eri lehmäpaikkamäärällä. Esimerkkien tulokseksi saadaan, kannattaako investointi käynnistää vai siirtää se myöhemmin toteutettavaksi, kun maidon hintariski otetaan huomioon. Tuloksena reaalioptiomenetelmälaskennasta saatiin, että esimerkkituotantorakennusinvestointi ei ole kannattava vuoden 2014 maidon tuottajahinnan keskiarvolla, ei vuosien 2012 - 2014 tuottajahinnan keskiarvolla, eikä useilla eri variaatioilla riskitasoja tai lehmäpaikkamäärää nostamalla. Investointi on kannattava riski huomioiden, mikäli maidon tuottajahinta olisi 0,49 €/l, jota se ei ole ollut koko tarkasteluajanjaksolla vuosina 2012 - 2014. Reaalioptiomenetelmä soveltuu hyvin maatalouden investointilaskentaan, sillä se on menetelmä, jonka avulla myös riskit saadaan hinnoiteltua ja otettua mukaan tarkasteluun, mikä on erityisen tärkeää isoja investointeja laskettaessa. Tutkimus on ajankohtainen sekä kiinnostava maitokiintiöiden poistumisen, maidon hintavaihtelun sekä tilakoon kasvun myötä.
  • Jauhiainen, Samuli (Helsingin yliopisto, 2015)
    This study focuses on machinery and equipment failures in agriculture. For example, unreliable operations, or breakages and obstructions are common failures. Usually failures interrupt the work, either temporarily or for a longer period of time. Sometimes it is possible to continue working despite the failure. On the other hand failures can cause delaying or financial losses. Repairs can cause dangerous situations for farmers. Maintenance and repair works on farms are causing the most of the work-related accidents. The main targets of the study were to determine the most common failures on agricultural machinery and equip-ment, find the main reasons for the failures and find the ways to prevent failures and accidents caused by failures. The study was intended to serve as a basis of the newsletter to be made for farmers. The study was conducted 1.5 years lasting follow-up study. This study was finally included 21 farmers from all over the Finland. Farmers reported their machinery and equipment failures according to a pre-defined form. According to the results most machinery and equipment faults occurs with tractors. That is because tractors have a lot of places for failures and they are widely used on farms. Also harvesting machines seems to have a lot of failures. Machine failures were mainly on the frame and on the mechanical parts of power transmission. About one-fifth of all were electrical failures. Around two times out of three the failure interrupts working. According to farmers most of the failures were age-related and result from a "normal" wear. The remaining causes for failures were divided almost evenly between operating environment, machinery and equipment poor quality and factors resulting from the users. A significant result is that many failures can be prevented. For farmers it is almost impossible to avoid the machine and equipment failures. This study and the earlier stud-ies show that many of failures can be prevented and farmers should prepare better for failures. According to study the most important ways to prevent failures are proactive maintenance, careful reading of the operation manual, in-vesting to good quality machinery and equipment and by focusing to the work they are doing. Machinery mainte-nance and failure solving is safe when maintenance facilities are decent, using high quality tools and protective clothes, and when using the correct methods of work and not taking extra risks. It is also important to remember that the most demanding repair work should be left to professionals. The main goals of the study were achieved. TTS has published a newsletter for farmers, "Agricultural machinery and equipment failures - prevention methods and guidelines" based on the results of this study.
  • Seyed Hameed, Ahkam Saddam (Helsingin yliopisto, 2015)
    Increased consumption of raw milk has been observed among the urban population in Europe along with an increasing consumer interest in foods that are less processed and locally produced. Raw milk and raw milk products have been associated with listeriosis caused by Listeria monocytogenes. These new trends in consumer behavior increase the need for more effective surveillance methods for L. monocytogenes at farm level. In Finland, raw milk sales are allowed directly from the farms to the consumer. The renewed Finnish national legislation stipulates that screening of L. monocytogenes on farms that sell raw milk includes five replicates of 25-ml bulk tank milk (BTM) samples. Due to dilution to the high volume of BTM, it is unlikely to detect low levels of bacterial contamination from the milk samples. Testing milk samples is also expensive and logistically difficult for continuous monitoring of L. monocytogenes at the farms. An alternative approach could be the testing of milk filters. Theoretically, milk filters may be more sensitive than BTM as a sampling material since all of the milk in the bulk tank has to pass through the filter. The objective of this longitudinal study is to compare milk filters and BTM for the best sampling material suitable for routine monitoring of L. monocytogenes in the dairy farms selling raw milk. Five BTM samples and a milk filter sample from two farms were tested for L. monocytogenes each week, for a period of 10 months, using NMLK 136:2010, ISO 11290-1:1996 and ISO 11290-2:1998 methods. The isolation of L. monocytogenes and other Listeria species were identified by API biochemical assay and multiplex PCR. The results indicate that milk filters are ideal as a sampling material in detecting L. monocytogenes than BTM samples. However, the presence of L. monocytogenes in milk filters was not associated to the presence of L. monocytogenes in BTM. Thus, milk filters could be used as indicators of the farm’s contamination status. Along with these findings, seasonal variation in detection, and advantages of identification methods were also discussed in this thesis.
  • Annala, Marja-Leena (Helsingin yliopisto, 2015)
    The goal of the research was to find out genetic gain and correlation of stem growth and quality traits in progeny trials of birch. Measurements and observation s of many traits are slow and expensive work. The costs could be decrease if some of the traits could be leaved unmeasured based on sufficient correlation between different traits. It’s very important to know association between different traits. Association can be even harmful. While some important trait becomes better some other can become worse. The internal and the external quality traits have a great importance for wood processing industry. The material of the research consists of eleven progeny trials established by The Finnish Forest Research Institute. Growth and quality trait were measured or observed. Measurements and observations were made at the age between 9-20 years. Change in mean of improved trait represents progress in tree improvement. This change is called genetic gain and it’s impressed usually as a relative value compared with mean of unimproved reference material. Reference material can even be other genetically improved material of different degree. Association between different traits was impressed with Spearman’s rank correlation coefficient. Nonparametric method was chosen because some traits were observed in rank order scales. Inconvenient for tree improvement is when association between growth and important quality traits is harmful. In this study was mainly found out remarkably genetic gain as well in growth as in quality traits in comparison with unimproved natural stand origins and even partly with earlier produced improved breeding material of different breeding degree. Correlation between stem volume and diameter at breast height were higher than between stem volume and height. There were several positive statistically significant correlations between growth and stem quality traits. Harmful correlation was found out between diameter at breast height and branch quality. Correlation between number of limbs and ramicorns had harmful correlation in some trials but correlations were quite weak. Ocular estimated general quality correlated well between its different factors. The costs of the practical forest tree breeding can be decreased by measuring fewer traits. Diameter at breast height is easy and quick trait to measure and correlate well between stem height and stem volume. Stem height could be leaved unmeasured. Because general quality correlates well between its different factors, other factors are not necessary to measure observe. Further research is needed within the reliability of the ocular observation. Differences in scaling within different person are important for reliability. Also the appropriate number of scales should be researched.
  • Eklund, Kirsi-Maria (Helsingin yliopisto, 2015)
    Yersinia enterocolitica is an important zoonotic food-borne pathogen which in Finland is reported to be the cause of hundreds of gastroenteritis cases a year. The species is very heterogenic and comprises of both highly virulent and harmless apathogenic strains. The sources of Y. enterocolitica infection and the reservoirs of pathogenic strains are not yet well-known. In this work, 91 Y. enterocolitica isolates from 39 domestic sheep were characterized using different phenotypic and genotypic methods. Three different biotypes were identified: usually harmless environmental biotype 1A, a common enteropathogenic biotype 2 and a rare pathogenic biotype 5. All biotype 2 and 5 strains carried chromosomal ail, inv, myfA and ystA genes, and plasmid borne virulence genes yadA and virF. Biotype 1A isolates carried several chromosomal virulence genes, Notably also the ail which has a strong correlation with Y. enterocolitica pathogenicity. In pathogenic biotypes, only natural resistance to antimicrobials was detected. In PFGE-analysis, biotype 1A had several genotypes, whereas strains belonging to biotypes 2 or 5 showed only a limited amount of variation. ail and gyrB genes were partially sequenced from a selection of strains, both of which revealed variation between different biotypes. This study indicates that sheep are a reservoir for pathogenic Y. enterocolitica in Finland. Without further analysis the link between sheep and human illness cannot yet be established.
  • Zhang, Xusheng (Helsingin yliopisto, 2015)
    Sterols and their conjugates are minor natural constituents in oils and fats. Plant sterols are also enriched in functional foods because of their known ability to lower serum cholesterol levels. Like other unsaturated lipids, sterols are prone to oxidize. In the literature review, thermo-oxidation reactions of free and esterified sterols were introduced and methods for the analysis of the formed products were summarized. The aim of the experimental research was to study the oxidation reactions of steryl esters. The oxidation reactions were studied at two temperatures, at 100 ºC and 180 ºC, by following the changes in the profiles of oxidation products varying in polarity and molecular size. The effects of esterification, unsaturation level of the acyl moiety in the sterol structure and temperature were studied. Solid-phase extraction (SiOH-SPE) and size-exclusion chromatography (SEC-RI) were applied for the separation and quantification of monomeric and oligomeric oxidation products. Silver coordination ion spray mass spectrometry (Ag+-CIS-MS) was applied to indicate mass ranges of the formed oxidation products. In the oxidation, sterol molecules first reacted with oxygen and then the formed monomeric oxidation products began to link with each other forming oligomers. Oligomers contributed to 17-90% and 23-78% of the oxidation products of steryl esters after 3 days and 2 hours of heating at 100 ºC and 180 ºC, respectively. Polar oligomers were the most abundant fraction at both temperatures. Non-polar oligomers were not formed in the oxidation of steryl esters. Increased unsaturation of the acyl moiety increased polymerization. Increased temperature changed the oxidation reactions and mid-polar oligomers became more dominant. Thermal reactions led to the loss of hydroxyl groups and hence the polarity of oligomers decreased. The molecular weight ranges of the most abundant oligomers and their fragments were m/z 900-1100 and 1300-1500 at 100 ºC. In conclusion, the oxidation of steryl esters begins by reactions with molecular oxygen after which the formed oxidation products begin to polymerize. This occurs both at auto-oxidation and thermo-oxidation conditions; i.e., at cooking and frying temperatures.
  • Vuorinen, Eeva (Helsingin yliopisto, 2015)
    In my thesis I explore the user experience in a new clothing-related service that is based on lending. The study is based on the users’ experiences of a clothing lending service called Vaatelainaamo. I have used a qualitative research method. The data was collected by personal interviews that followed the form of theme interviews. The data is analyzed according to the themes and research literature addressing product-service system, shopping, emotional and symbolical meanings of clothing as well as sustainable consumption. The purpose of the themes is to explore the experiences and the preconditions for adapting new clothing-related product-system services. In addition the purpose is to understand the meaning of clothing as material possessions and the challenges consumers face in the field of sustainable clothing consumption. The findings of the study indicate that lending clothing represents sustainable way of clothing consumption. Attributes most contributing to positive perceptions of the service is the available assortment of clothing and the social aspect of the service. In order to gain user satisfaction, the assortment of clothing is to meet the size and style requirements of the user. In addition the ease use of the service including the store location, opening hours and the easy maintenance of the clothing were found to be the main factors contributing to the user satisfaction. In my study, the importance of owning clothing is determined through the functional and symbolical meanings of the clothing. The functionality is mainly experienced through the ease of use and functionality of the clothing in everyday life. Quality, good fit and attachment, which is formed through use, were found to be the main contributors for functionality. The importance of owning clothing is restricted to basic and trustworthy clothing as well as to meaningful clothing that represented certain memories. However, the desire for variation, which is experienced through clothing, is hard to fulfill with the basic and functional clothing. Lending is found to be a good way to satisfy the desire for variation without attachment to material possessions. According to the study sustainable ways to consume clothing is seen as a trivial matter. Consumers have different practices in order to attain sustainability including decreasing consumption, saving and investing in quality. Overall the interviewees’ experience that lending clothing is an effective way to question the consumption practices and the real needs related to clothing. Lending service is also found to have an educational feature, as the users’ knowledge of Finnish designers, quality and maintenance of clothing is cultivated through the use of the service.
  • Tavakoli, Ali; Tavakoli, Ali (Helsingin yliopisto, 2015)
    Recently, a new muscular disorder has been reported in chicken M. pectoralis major called Wooden Breast that might be linked to intensive growth selection. The purpose of this study was to find the influence of Wooden Breast condition on protein composition of the breast muscle with special emphasis on myofibrillar and sarcoplasmic protein fractions. For fulfilling the aims of the study, a total number of 34 pectoralis major muscles from both Wooden Breast and normal chickens (Ross 508, Aviagen Ltd, Scotland) were used to evaluate protein composition, protein profile of sarcoplasmic and myofibrillar proteins and their changes, by doing one-dimensional SDS-PAGE analysis. M. Pectoralis major defected by Wooden Breast demonstrated significant decline in sarcoplasmic (P?0.001) and myofibrillar (P?0.05) protein content, in comparison with normal breast muscles. Furthermore, gel electrophoresis indicated significant changes in the intensity of 18 sarcoplasmic protein bands and 7 myofibrillar protein bands. Majority of affected sarcoplasmic proteins were glycolytic enzymes. Moreover, impacted myofibrillar proteins play a role in muscle fibre integrity (e.g. desmin) or calcium signalling. Results of the present study also revealed desmin overexpression with coexistence of a desmin fragment in Wooden Breast which was confirmed by Western-blot technique. In conclusion, the findings of this study indicated defected chicken breast with Wooden Breast contained less protein and the composition differed compared to normal chicken breast muscle, which proves the influence of Wooden Breast condition on protein characteristics of chicken breast muscle. Further studies are needed to interpret the protein changes in the Wooden Breast and the possible role of these changes on metabolic and structural status of the muscle.
  • Kallio, Jaakko (Helsingin yliopisto, 2015)
    Tämän tutkielman tavoitteena oli selvittää biomassojen kuljetusetäisyyksien vaikutus energiataseeseen maatilojen yhteiskäyttöisessä biokaasulaitoksessa. Työssä keskitytään naudan lietelannan käyttöön syötemateriaalina, koska yhtenä lähtöoletuksena oli että lietteen suuri vesipitoisuus on haaste sekä logistiikalle että koko biokaasulaitoksen energiataloudelle. Tutkimus keskittyy energia-analyysiin, eikä sisällä lainkaan talouslaskelmia. Tutkimus perustuu energiataselaskentaan ja tuloksia havainnollistetaan kuvitteellisen biokaasulaitoksen avulla. Kuvitteellista biokaasulaitosta varten kerättiin tietoja Pohjois-Pohjanmaalla sijaitsevan pienen kylän lähettyvillä olevilta karjatiloilta. Alueelle suunniteltiin maatilojen yhteinen biokaasulaitos ja sille tehtiin energia-analyysi. Lisäksi tehtiin herkkyysanalyysi, jossa testattiin energiataseen eri tekijöiden muutoksen vaikutusta taseeseen. Laskelmat tehtiin sen mukaan, että laitos käyttäisi syötemateriaalinaan pelkkää naudan lietelantaa. Tämä siksi, että voitiin tarkastella nimenomaan lietteen käyttöä energiatalouden näkökulmasta. Näin ollen paremman kaasupotentiaalin omaavat syötemateriaalit eivät päässeet vääristämään energia-analyysiä. Tulokset osoittivat, että kun maatilat, joilta syötemateriaali kerätään, sijaitsevat noin kymmenen kilometrin säteellä biokaasulaitoksesta, on kuljetuksen energiankulutus pieni tekijä laitoksen energiavirroissa. Kuljetuksen sijaan merkittäviä tekijöitä biokaasulaitoksen energiataseen kannalta olivat syötemateriaalin eli lietteen kuiva-ainepitoisuus ja lämpötila syöttöhetkellä.
  • Ilonen, Iikka- Santeri (Helsingin yliopisto, 2015)
    Since 1980s the major global forest industry enterprises have been renounced their forest holdings in Northern- America and sold them for the public and private institutions as well as for the private investors. Since 1990s until 2010s corresponding renouncement have been distinguished also in Europe. Especially because of the quarterly reporting the trend between major global forest industry enterprises have been towards renouncing fixed capital in desire to satisfy the needs of investors. In the beginning of the millennium the global forest products companies have been transposing manufacturing into emerging markets. The predicted growth opportunities and demand expectations in regard to forest based products are cut out for induce the global forest industry enterprises to invest in forest holdings in emerging markets. The increasing competition of bare land in emerging markets has been a major driver to switch the strategy of global forest industry enterprises back into vertical integration in lieu of buying the raw material from the markets. This Master’s Thesis takes a look at the relationship between timberland ownership (vertical integration) and financial performance of a forest industry enterprise. In addition this thesis aspires to substantiate whether there exists a relationship between timberland ownership and the geographical location of operations of a global forest industry enterprise. The material covers review of literature, the theories of industrial economics, annual reports of forest industry enterprises and the survey of TOP 100 global forest, paper and packaging industries. (PricewaterhouseCoopers 2007; 2012). Statistical hypothesis test and descriptive statistics are utilized to analyze the results received from the annual reports and the surveys of TOP 100 global forest paper and packaging industries. Conclusions regarding the relationship between timberland ownership and financial performance are drawn from the results received. In addition the results produce information on the current state of the timberland holdings between the TOP 100 major global forest industry enterprises. Quantitative data behind this study has been collected from years 2007 and 2012. The findings of this study verifies the trend towards timberland ownership between major forest industry enterprises. Regarding on the results attained from the statistical test there exists a positive correlation between timberland ownership and financial performance. In the future especially the prices of raw material, prices of bare land and prices of end- product will continue to play a crucial role for the profitability of global forest industry enterprises. Finally, it is interesting to see in the future how the green economics will shape the Forest Industry and what kind of an impact it will have for the profitability and forest ownership of global forest industry enterprises.
  • Carlson, Paul (Helsingin yliopisto, 2015)
    Efficient utilization of renewable plant and crop based biomass is one of the main areas of study in industrial biotechnology. Roughly 20-30 % of all plant biomass consists of hemicellulose, a polymer composed of six carbon (hexose) and five carbon (pentose) sugars. This proves a challenge in utilizing all available plant biomass efficiently, since many micro-organisms, which for instance readily ferment glucose (a hexose) into ethanol, will not do so for pentose sugars. Alternative pathways for utilization of pentose sugars are being looked for. Characterization of the Caulobacter crescentus D-xylonate dehydratase (Cc XyDHT) was the aim of this study. Cc XyDHT belongs to the ILVD/EDD protein family, whose members incorporate an iron-sulfur (FeS) cluster into their protein structure coordinated by two to four cysteine amino acids. Removal of the cysteine ligands should disrupt the incorporation of the FeS cluster, and thus presumably the activity of the enzyme. Three cysteines in Cc XyDHT which could act as ligands for the FeS cluster had previously been identified by sequence alignment among the ILVD/EDD family. Accordingly, four single cysteine-to-serine mutants of the Cc XyDHT as expression plasmid constructs were designed, with a non-conserved cysteine residue selected as a control. The wild type and mutated Cc XyDHTs were produced in Escherichia coli and purified with affinity chromatography using Strep-tag. SDS-page and Western blotting with an anti-Strep-tag antibody were used to confirm that the expressed proteins were Cc XyDHTs. The mutations’ effects on the protein fold and to the presence of the FeS cluster were investigated with UV and circular dichroism spectroscopy. Cc XyDHT catalyzes the conversion of D-xylonate into 2-keto-3-deoxy-xylonate. A colorimetric assay using thiobarbituric acid (TBA) as the reactant was used to measure enzymatic activity. The pH and temperature optima, substrate specificity, and enzyme kinetics of the wild type Cc XyDHT were determined. For the two best substrates, kcat/Km = 1220 mM/min for D-xylonate and kcat/Km = 1160 mM/min for D-gluconate were found. All three conserved mutations were found to reduce enzymatic activity more than 99 % with these substrates. Depending on which cysteine was disrupted, differences in the kinetic constants between D-xylonate and D-gluconate were found. The non-conserved mutation reduced activity by approx. 40 %. The spectroscopic results indicate that the three conserved mutants lacked the FeS cluster, while the non-conserved mutant still incorporated it. It can be concluded that the three conserved cysteines are involved in coordinating the FeS cluster, which itself plays an important role in the catalytic activity of Cc XyDHT. These findings should be helpful for follow-up studies in biotechnological application of pentose sugars acids and their derivatives.
  • Jääskeläinen, Miiro (Helsingin yliopisto, 2015)
    Dityppioksidi eli typpioksiduuli (N2O) on voimakas kasvihuonekaasu, joka tuhoaa yläilmakehän otsonikerrosta. Maaperässä muodostuu dityppioksidia nitrifikaatio- ja denitrifikaatioprosesseissa. Palkokasvien symbionttisessa biologisessa typensidonnassa Rhizobium-bakteeri käyttää kasvilta saatua energiaa ilmakehän N2-typen ja vedyn yhdistämiseen ammoniumtypeksi ja edelleen aminohapoksi, jota se luovuttaa isäntäkasville. Biologisen typensidonnan N2O-päästöjä on arvioitu korkeiksi. Heinä-. ja palkokasvien seosviljely on yksi keino tehostaa typen ja muiden ravinteiden käyttöä sekä nostaa satoja. Seosviljelyssä juuristo on laajempi ja kilpailu ravinteista kovempi kuin puhdaskasvustoissa, minkä oletetaan johtavan tehokkaampaan typenottoon maasta. Viikissä tehdyssä kaksivuotisessa kenttäkokeessa viljeltiin vuohenhernettä (Galega orientalis, palkokasvi) ja rehukattaraa (Bromus inermis, heinäkasvi) puhdaskasvustoina ja seosviljelmänä. Lisäksi kokeessa oli avokesantoruutuja. Koe tehtiin liejusavimaalla, jossa oli runsaat luontaiset orgaanisen typen varannot (0-50 cm:in pintamaassa noin 20 t N /ha). Maan N2O-päästöjä, ammonium- ja nitraattitypen pitoisuutta sekä kosteutta mitattiin kesäaikana 2011 ja 2012. N2O-mittaukset tehtiin suljetun ja staattisen kammion menetelmällä. Näytteenottoa varten kehitettin menetelmä kaasuampullien puhdistamiseen taustapitoisuuksista heliumilla. Biologinen typensidonta tuotti seosviljelmissä 40-70 kg N/ha ja ainoastaan vuohenhernettä sisältäneissä ruuduissa 195-225 kg N/ha orgaanista ja mineraalityppeä verrattuna ainoastaan maasta mineraalityppeä saaneeseen rehukattaraan. Vuohenherneen ja rehukattaran seosviljelmässä maan nitraattitypen pitoisuus pysyi yhtä alhaisena kuin pelkkää rehukattaraa viljellessä, eikä N2O-päästöjä myöskään muodostunut enempää. Ureana (OC(NH2)2) annettu typpilannoitus ei tässä maassa nostanut rehukattaran satoa merkittävästi, koska maassa oli runsaat kasveille käyttökelpoiset typpivarat. Välittömästi lannoituksen jälkeen havaittiin korkeita nitrifikaatioon liittyviä N2O-päästöjä. Lannoitetut rehukattararuudut toimivat kuitenkin loppukesästä vähäisinä N2O-nieluna. N2O-päästöt olivat pienimmät pelkkää rehukattaraa sisältävissä ruuduissa ja seosviljelmissä. Vahva korrelaatio maan nitraattimuotoisen mineraalitypen ja N2O-päästöjen välillä viittaa siihen, että päästöt muodostuivat suurimmaksi osaksi denitrifikaatiossa. Nitraattipitoisuudet ja dityppioksidipäästöt olivat koejäsenistä suurimmat avokesannossa, jossa maan suuri nitraattitypen pitoisuus selitti maan suuret N2O-päästöt. Seosviljelmän ja pelkän rehukattaran N2O-päästöt olivat 120-140 g N/ha ja pelkkää vuohenhernettä sisältäneiden viljelmien 500 g N/ha. Tulokset tukevat käsitystä, että jos viljelykasvien typenotto on tarpeeksi tehokasta, jotta maan nitraattipitoisuus ei pääse kohoamaan, ei biologisesta typensidonnasta aiheudu korkeita N2O-päästöjä.
  • Lepikkö, Katri (Helsingfors universitet, 2015)
    Tehostunut maatalous on maailmanlaajuisesti köyhdyttänyt maatalousluontoa voimakkaasti viime vuosikymmenten aikana. Tehostumisen seurauksena niittyjen ja viljelemättömien pientareiden määrät ovat romahtaneet, maankäyttö on voimistunut ja biologinen monimuotoisuus on vähentynyt. Tila- ja lohkokokojen kasvu on yksipuolistanut maaseutumaisemaa ja heikentänyt maaseutuympäristöstä riippuvaisten lajien elinehtoja. Lisäksi karjatalouden ja siihen liittyvän niiton ja laidunnuksen vähentymisen seurauksena erityisesti perinteiset niitty- ja ketolajit ovat vähentyneet merkittävästi. Nykyään jo noin viidennes Suomen uhanalaisista lajeista elääkin maatalousympäristössä, erityisesti perinnebiotoopeilla. Useimmista maatalousluonnon eliöryhmistä on huomattavan vähän tietoa saatavilla. Tämän vuoksi harvoja hyvin tunnettuja lajiryhmiä joudutaan käyttämään epäsuorina indikaattoreina muunkin lajiston tilasta. Suomessa parhaiten tähän tarkoitukseen soveltuvat eliöryhmät ovat päiväperhoset, peltolinnut ja peltojen rikkakasvit. Jotta lajeja voidaan suojella tehokkaasti, tarvitaan tietoa lajeille suotuisista elinympäristöistä ja niiden sijainnista. Elinympäristömallit ovat oiva työkalu tähän, sillä niiden avulla voidaan selvittää lajien ja ympäristötekijöiden välistä suhdetta ja arvioida lajien esiintymisen todennäköisyyttä eri alueilla. Tämän työn tavoitteena on arvioida maatalousympäristön arvotuksessa käytetyn High Nature Value (HNV) -indikaattorin soveltuvuutta maatalouden tukien suuntaamiseen maatalousympäristön perhosten levinneisyysaineiston avulla. Arviointia varten tuotin tilastollisia maatalousympäristön perhoslajien elinympäristämalleja ja esiintymisen ennustekarttoja. Käytin elinympäristömallien rakentamiseen R-ohjelmointiympäristön biomod2-pakettia. Mallien kalibrointivaiheeseen edenneistä 49 perhoslajista 30 lajia oli sellaisia, että niille saatiin rakennettua sekä yksittäisillä menetelmillä että painotetun keskiarvon konsensusmenetelmällä vähintään hyvät (TSS-arvo vähintään 0,6) elinympäristömallit. HNV-indikaattorin pisteiden ja perhoslajien esiintymistodennäköisyyden väliset riippuvuudet olivat vähäisiä ja vaihtelevia. Lisäksi myös negatiivisia riippuvuuksia esiintyi. HNV-indikaattorin käyttö maatalouden tukien suuntaamisessa ei siis saanut perhosten osalta tässä työssä tukea. Mallinnus tehtiin maisematasolla ja maisematason vaikutuksia voikin ylipäätään olla vaikea havaita, sillä luonnonarvoiltaan arvokkaat elinympäristöt ovat usein harvassa ja kaukana toisistaan. Yksittäinen HNV-tila ei välttämättä juurikaan lisää lajien monimuotoisuutta ja elinmahdollisuuksia, jos sitä ympäröivä maisema on tehotuonnossa. Perinnebiotooppien vähetessä maatalousympäristön lajeja onkin tulevaisuudessa tärkeää suojella entistä enemmän myös esim. kaupunkiympäristön viheralueilla ja johtoaukeilla.
  • Petruneva, Ekaterina (Helsingin yliopisto, 2015)
    The present work was based on the analysis of glyphosate concentrations in six soil layers after continuous multiple applications of herbicide products and various sampling times during the study period of 2010?2012, and aimed to contribute to a better recognition of the glyphosate persistence in clay soil. Two tillage methods (conventional tillage and no-till) were carried out in two replicates on the experimental field located in Jokioinen, South-Western Finland. This experiment was important for the identification of glyphosate amounts in soil profile and for planning a better field management in the future on the larger scale. Results of the study demonstrated that glyphosate and its metabolite AMPA remained on the field a year after the spraying of the herbicide. Calculated reference degradation rate constants and half-lives were proved to be in a range with literature review. While the impact of tillage methods on the glyphosate retention in soil was not possible to assess by the present study due to the quite sparse nature of the data, the residuals of glyphosate and AMPA at deep layers were almost non-detectable. Study clearly showed that accumulation of glyphosate happens mostly in topsoil, and the leaching potential into deeper layers was quite limited.
  • Kangas, Jaakko (Helsingin yliopisto, 2015)
    New primary tillage methods have appeared alongside traditional ploughing. Objectives of primary tillage can nowadays be achieved with other methods such as by exploiting nature’s own processes or with chemical weed control. The endeavor of farmers to save time and money has caused conservation tillage to become more common. Different methods of conservation tillage and no-tillage has been replacing traditional ploughing. Conservation tillage has had various kinds of effects to achieved yields. Some international studies reported that conservation tillage had reduced yields. On the other hand, the rest of the studies point out that either the yield remained at the same level or at times, yield levels rose with reduced tillage. The aim of this study was to determine the profitability of different tillage methods. The profitability of three different primary tillage methods were compared at three farm sizes (50, 100 and 200 ha). Retail prices of farming machinery and Luke’s on-going field experiments on clay soil in Jokioinen were drawn on for data used in this study. Luke has been running no-tillage field experiments in Jokioinen since 2000. Yield data of spring barley from Jokioinen field experiment was used in this study. No-tillage was the most profitable tillage method on every farm size. The costs of no-tillage was 145?279 €/hectare lower than the costs with ploughing and 111?234 €/hectare lower than the costs with cultivation. The surplus of no-tillage was 93–226 €/hectare greater than surplus with ploughing and 69?192 €/hectare bigger than the surplus achieved with cultivation as a primary tillage. The profitability of cultivation was 16–34 €/hectare bigger than the surplus acquired through ploughing. No-tillage was more economically beneficial on a field which had less clay in its texture. The no-tillage’s surplus was 183?317 €/hectare bigger than the ploughing’s surplus and it was 161?284 €/hectare bigger than the cultivation’s surplus. Fields of similar size were used when analyzing the difference of profitability between ploughing and cultivation. This study asserts that the profitability of primary tillage method depends on machinery, weather conditions, soil type and the size of the farm. In this study, no-tillage was more profitable even though the yields produced were less than with traditional primary tillage. The profitability of the different primary tillage methods varied erratically between farms and for this reason, an unambiguous answer for profitability cannot be given.
  • Tasiyana, Diana Tendai (Helsingin yliopisto, 2015)
    The shelf life of ESL milks and pasteurized creams is limited by bacterial spoilage. The current state of knowledge with respect to the diversity and activities of the spoilage microflora in these products is still limited. To date, studies on this subject are yet to be carried out in Finland. The aim of this study was to characterize the spoilage microorganisms found in ESL milks and pasteurised creams mainly produced in Finland. 10 ESL milks and 8 pasteurised cream packages were obtained from the Finnish retail market and were stored at 8?C, 15?C, room temperature and 30?C, respectively, until expiration. Total bacterial counts were evaluated and 31 bacterial isolates were selected. An attempt was made to characterize the bacterial isolates using rpoB and 16S rRNA partial gene sequence analyses. Psychrotrophic, spore-forming and spoilage features were also determined. Strain diversity was determined by rep-PCR profiling. Five selected isolates were subjected to metabolic profiling using the API50 CHB test. When growth was detected, total bacterial counts ranged from 2.67 to 3.74 and 2.54 to 8.98 log units in cream and ESL milk samples, respectively. Both ESL milks and cream samples were dominated by heat-resistant, spore-forming species of the Bacillus genera: the isolates were related to B. licheniformis. B. weihenstephanensis, B. safensis, B. kochii, B. pumilus, B. subtilis and B. anthracis. Intraspecies and intrasample strain diversity was very high. Isolates mainly displayed proteolytic and lipolytic activity. Psychrotrophic activity was high in the cream samples while most ESL milk isolates were mostly mesophilic. Tested isolates were non-lactose fermenters and had varying metabolic profiles. The study revealed that Finnish ESL milks and pasteurized creams are prone to spoilage by species of the Bacillus genera that have potential for lipolytic and proteolytic spoilage and some of which are considered toxigenic. There is wide intraspecies strain diversity responsible for the wide variability in metabolic, psychrotrophic and spoilage features. Phenotypic tests based on API50 CHB cannot be relied upon to make conclusions on taxonomy. Combining various methods is important for the comprehensive characterization of the bacterial isolates. Strategies to eliminate bacterial species of the Bacillus genera are important to prolong shelf life. However, intervention should be strain-specific to be effective. Large scale studies are required to confirm findings from this study.
  • Nurminen, Hanna (Helsingin yliopisto, 2015)
    The thesis focuses on essential consumption of university students in Helsinki metropolitan area. This study utilizes the consensual or so called consumer-driven method for building reference budgets in which the students have participated in. The data were collected in four group interviews with a total of 19 college students. On the basis of group interviews of higher education students, the reference budget is built on a reasonable minimum, according to the monthly and annual basis. Budget reference is built on consumption expenditure groups which are: food, housing, mobility and travel, clothing, household goods and appliances, leisure, and health and hygiene. Data has been analyzed with content analysis and thematic analysis. This work aims to answer how the necessary consumption of university students is composed, and how they perceive the adequacy of their money and how they fund living. The aim is to determine which kind of consumption determines the minimum level of consumption, with which university students get along and feel that they can participate in social activities. The study shows that the student benefit is not enough to cover the necessary expenditure of university students. Interviews show that the main aids for economic survival are student loans, support from parents and work. According to the interviewees, work slows the progress of studies. In group interviews, the students reacted quite positively to their economic situation. Some, however, felt that survival was difficult and, for example, without parental support, it would be almost impossible. Only a few of the interviewees is trying to survive only with student benefit, but they have to calculate very carefully what they are able to buy.
  • Innanen, Laura (Helsingin yliopisto, 2015)
    The aim of the study was to optimize growth media and its composition for one Lactobacillus strain. The purposes of the optimized culture media for fermentation were to maximize cell count and amount of viable cells during processing. The raw materials for growth media had to be suitable for industrial use. The study was performed by Bioscreen and fermentation tests in different growth media. At first ability of the strain to grow was tested by Bioscreen C with different raw materials and their compositions. According to literature, six carbon, four nitrogen sources and three other raw material were chosen to Bioscreen tests. Bioscreen C measured turbidity (OD value) of cultivation. According to the results from Bioscreen tests, optimal raw materials were chosen to the fermentation tests. The optimal carbon sources were whey permeate powder and glucose, the optimal nitrogen sources casein peptone and yeast extract and other raw materials manganesulfate, magnesiumsulfate and yeast extract. The cultivations were made in a bioreactor (Biostat Q). The starter strains were concentrated and freeze-dried. Samples from cultivated, concentrated and freeze-dried starter strain were analyzed (cell counts, optical density, growth rate, base consumption and survival-%). Results were compared to those obtained using control medium that is known to support the growth of the Lactobacillus strain. Lactobacillus strain was able to grow in different growth media. In Bioscreen tests compositions of growth media have major effect on lactobacilli growth. Bioscreen experiments revealed that in most cases the Lactobacillus strain grew to higher OD values in the composed media compared to control medium. In Bioscreen tests the sugar based growth media required more added minerals and yeast extract than whey permeate based media. Yeast extract was found to promote Lactobacillus growth in Bioscreen tests. In fermentation tests cells grew on growth media equally as on control media. Suitable alternative options for growth media were found from tests for further studies. Further studies can research functionality of the raw materials in production scale and preservation of the cell concentration during storage.