Browsing by Subject "mikro-organismit"

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  • Björklöf, Katarina; Salminen, Jani; Sainio, Pirjo; Jørgensen, Kirsten (2008)
    Evidence for on site biodegradation may be difficult to provide at heterogeneous sites without additional experiments in controlled laboratory conditions. In this study, microbial activities measured as CO2 and CH4 production were compared in situ, in intact soil cores and in bottle microcosms containing sieved soils. In addition, biodegradation rates were determined by measuring the decrease in petroleum hydrocarbon concentrations at 7°C in aerobic and anaerobic conditions. Elevated concentrations of CO2 and CH4 in the soil gas phase indicated that both the aerobic and anaerobic microbial activity potentials were high at the contaminated site. Aerobic and anaerobic microbial degradation rates in laboratory experiments of petroleum hydrocarbons were highest in soils from the most contaminated point and degradation in the aerobic and anaerobic microcosms was linear throughout the incubation, indicating mass-transfer-dependent degradation. Different results for microbial activity measurements were obtained in laboratory studies depending on pretreatment and size of the sample, even when the environmental conditions were mimicked. These differences may be related to differences in the gas exchange rates as well as in changes in the bioavailability of the contaminant in different analyses. When predicting by modeling the behavior of an aged contaminant it is relevant to adapt the models in use to correspond to conditions relevant at the contaminated sites. The variables used in the models should be based on data from the site and on experiments performed using the original aged contaminant without any additions.
  • Niemi, Maarit; Niemi, Jorma (Vesihallitus. National Board of Waters, 1979)
    Vesientutkimuslaitoksen julkaisuja 34, 68-73
    Bakteerien ja bakteriofaagien esiintyminen puhdistetussa jätevedessä vuorokauden aikana ja puhdistamon viipymän määrittäminen.
  • Gyllenberg, Helge; Hanioja, Pauli; Vartiovaara, Unto (Suomen metsätieteellinen seura, 1954)
  • Stigzelius, Tiina (Helsingfors universitet, 2016)
    For the conservation of biodiversity, it is important to examine the factors that shape species richness in different ecosystems. Global warming is predicted to be most pronounced in arctic-alpine areas and arctic environments, especially in major ecotones, like environments close to the tree lines. Therefore by examining the species richness, distribution and requirements of species living in mountainous areas, it is possible to assess the effects of climate change in different spatial scales. Elevational gradients are suitable for this kind of research, because many ecosystems processes and structure of local communities change along elevational gradients. Studies carried out in elevational gradients can help us to find out the mechanisms that shape local communities. The elevational patterns of species richness of micro-organisms like diatoms have been studied increasingly lately, but the results of the factors shaping species richness along elevational gradient are varied between different studies and groups of micro-organisms. Therefore it is important to learn more about the factors that shape species richness of micro-organisms along elevational gradients. In this thesis’s the elevational patterns of species richness and species evenness were studied in three different mountain streams in northern Norway and Kilpisjärvi (n= 44). The study also examines the effects of altitude to taxonomic relatedness of diatom species. Diatom and water chemistry samples were collected in August 2013. Generalized linear models (GLM) were used to analyse species richness and the correlation between environmental variables and species richness were examined with pairwise correlation tests. Taxonomic distinctness was calculated with taxondive-command. According to the GLM, the species richness was best explained (49,2 %) by pH of stream water, stream depth, conductivity and altitude. Species evenness was best explained (45,6 %) by water temperature and total nitrogen (TN). Altitude showed a statistically significant relation to species richness (p= 0,003) and species evenness only in Lepänjoki (p< 5,45e+07). Species were not phylogenetically more clustered as elevation increased. Altitude did not explain the taxonomic distinctness of diatom species in the research streams. It can be concluded that a deeper riverbed guarantee more stable conditions to diatom species. Similarly, higher water pH value is more favorable habitat for diatoms, than acidic waters. Altitude may affect species richness through bedrock geology, which probably affects pH value and conductivity in the research streams. The short elevational gradients probably affect the fact that species richness did not decrease as altitude increased and that the species were not closely related to each other at the upper end of the gradient.
  • Hallaksela, Anna-Maija (Suomen metsätieteellinen seura, 1977)
  • Jalkanen, Kaisa; Hyvärinen, Anne; Björklöf, Katarina; Leivuori, Mirja (Suomen ympäristökeskus, 2013)
    Suomen ympäristökeskuksen raportteja 24/2013
    Terveyden ja hyvinvoinnin laitoksen (THL) Ympäristömikrobiologian yksikkö järjesti yhdessä Proftest SYKEn kanssa vertailukokeen asumisterveystutkimuksia tekeville laboratorioillejoulukuussa 2012. Näytteinä olivat rakennusmateriaalinäyte ja suspensionäyte. Näytteistä määritettiin sienten ja bakteerien kokonaispitoisuudet, eri sienisukujen pitoisuudet sekä aktinomykeettien pitoisuudet. Pätevyyskokeeseen osallistui yhteensä 21 laboratoriota. Mittaussuureen vertailuarvona käytettiin osallistujien tulosten robustia keskiarvoa. Pätevyyden arvioimisessa käytettiin z-arvoa ja kakkia, paitsi kolmea, analyyttia arvioitiin. Vertailuarvosta sallittiin kaksi kertaa robustin keskihajonnan poikkeama vertailuarvosta. Kokonaisuudessaan hyväksyttäviä tuloksia oli 91 %. Suurin osa laboratorioista toimi Asumisterveysohjeen ja annettujen ohjeiden mukaisesti, mutta muutamien laboratorioiden toimintatavoissa on tarkistamisen tarvetta. Kaikki vertailukokeeseen osallistuneet laboratoriot päätyivät samaan tulkintaan mikrobikasvusta tai vauriosta materiaalinäytteessä.
  • Tamminen, Timo (Vesihallitus. National Board of Waters, 1984)
    Vesientutkimuslaitoksen julkaisuja 56, 11-20
    Michaelis-Menten -kinetiikan lineaarimuunnokset luonnon mikrobiyhteisöjen tutkimuksessa
  • Vanhala, Pekka (Finnish Environment Institute, 1999)
    Monographs of the Boreal Environment Research 14
  • Tamminen, Timo; Kuparinen, Jorma (Vesihallitus. National Board of Waters, 1984)
    Vesientutkimuslaitoksen julkaisuja 56, 3-10
    Vesistöjen bakteeriplanktonin aktiivisuuden mittauksesta radioaktiivisten merkkiaineiden avulla
  • Timonen, Sari; Valkonen, Jari (Gaudeamus, 2018)
    Sienten biologia on ensimmäinen suomenkielinen yleisteos sienistä. Siitä selviävät perusasiat sienten monimuotoisuudesta, aineenvaihdunnasta, genetiikasta, toimintatavoista, ympäristövaikutuksista ja käytöstä ihmisen hyödyksi. Kirjan lukemista ja sienimaailman ymmärtämistä helpottaa kattava suomenkielinen sienitieteellinen sanasto. Kirja sopii luettavaksi niin opiskelijoille, tutkijoille, biologian opettajille kuin sieniharrastajillekin. Kirjoittajina ovat alansa parhaat suomalaiset asiantuntijat.