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Faculty of Agriculture and Forestry


Recent Submissions

  • Potila, Johanna (2023)
    Abstract Faculty: Faculty of Agriculture and Forestry* and Faculty of Medicine *coordination Degree programme: Master′s program in Microbiology and Microbial Biotechnology Author: Johanna Potila Title: Characterization of potentially therapeutic bacteria from a healthy fecal donor. Level: Master′s thesis Month and year: August 2023 Number of pages: 40 Keywords: Clostridioides difficile, dysbiosis, FMT, next-generation probiotics, adhesion, anti-inflammatory Supervisors: PhD Kaisa Hiippala, PhD, Docent Reetta Satokari and PhD Pauliina Lankinen Where deposited: E-thesis University of Helsinki Abstract: Recurrent Clostridioides difficile infection (rCDI) is a healthcare-associated infection related to antibiotic use, that causes significant morbidity and mortality. Fecal microbiota transplantation (FMT) is the most effective treatment for rCDI and it is successful in nearly 90% of patients. However, there are some risks related to FMT use such as the potential risk of transferring pathogens or other phenotypes despite donor screening. Defined bacterial mixtures consisting of endogenous commensal gut microbes with beneficial properties could be used instead of FMT to mitigate the risks and improve the availability of the treatment. 12 bacterial strains previously isolated from a healthy fecal donor were characterized in this study. At first, oxygen tolerance and culturability of the isolates in several different media were examined. The second aim was to investigate if these isolates are safe for bacteriotherapeutic use by testing hemolytic properties, antibiotic susceptibilities and proinflammatory properties. The third objective was to investigate potential beneficial properties such as adherence of the isolates to mucus and epithelial cell lines and anti-inflammatory effects on epithelial cells. Caco-2 and HT-29 cell lines were used as a model of intestinal epithelial cells. Growth was abundant on standard brain heart infusion (BHI) medium supplemented with 0,5% yeast extract and more than half of the isolates tolerated the 4-hour oxygen exposure. These results suggest that many of the strains have good production characteristics. All 12 isolates were non-hemolytic and most of them were susceptible to many commonly used anti-microbials such as amoxycillin/clavulanic acid and piperacillin/tazobactam. Low induction of interleukin-8 (IL-8) release from HT-29 cells was observed for all the isolates which indicates no pro-inflammatory effect. These safety tests suggest that the isolates are safe for therapeutical use. Adhesion to mucus and intestinal epithelial cells (HT-29, Caco-2) was low to moderate (2-7%), which can potentially promote their colonization in the gut. No attenuation of Escherichia coli lipopolysaccharide (LPS)-induced IL-8 release from HT-29 cells was observed, which indicates that characterized strains do not have anti-inflammatory effects on epithelial cells. However, it is likely that they have some other important roles in the gut e.g., in cross-feeding networks and can thus help with restoration of a healthy, diverse gut ecosystem. In conclusion, the characterized isolates could be suitable for bacteriotherapeutic use in the treatment of rCDI.
  • Järveläinen, Mikko (2023)
    Urban development can generate substantial greenhouse gas emissions through deforestation and land-use change. This underscores the urgency for effective climate change mitigation strategies. This thesis scrutinizes the feasibility of local forest conservation, specifically at a municipal level, as a strategy to compensate for losses in carbon storage and reductions in carbon sequestration linked to land-use changes. The study uses a case study approach, focusing on a proposed development of a data centre in Espoo's Hepokorvenkallio area in Finland. The proposed construction site spans 19 hectares and consists mainly of a forest earmarked for clearance. As a possible countermeasure, the city is considering conserving the nearby Hynkänlampi forest, covering an area of 79 hectares. The study leverages empirical modelling via long-term forest simulations to assess carbon storage and sequestration dynamics for these two sites under different scenarios. For Hepokorvenkallio, the analysis compares a construction scenario with continued forest management. The findings suggest that land clearing necessary for construction could result in a carbon storage loss of 15,820 tCO2 over a century, thereby indicating a need for compensatory measures. For Hynkänlampi, the modelled forecasts propose that a conserved forest could theoretically offset these losses. However, the offset capacity is notably influenced by the chosen discount rates applied to the carbon storage values. While simulation results for Hynkänlampi indicate a buffer capacity exceeding 10,000 tCO2 with a 0% discount rate, this buffer decreases to approximately 5,800 tCO2 with a 1% discount rate. Beyond the numerical aspects of carbon accounting, the thesis also addresses existing uncertainties and the prevailing regulatory landscape for carbon accounting procedures. Considering Finland's current legal and regulatory framework, the interpretation of this study posits that Espoo could view forest conservation at Hynkänlampi as a viable carbon offsetting measure to mitigate the impacts of land clearing at Hepokorvenkallio.
  • Vega Olivares, Cinthya (2023)
    This thesis examines the effects of Internationally Transferred Mitigation Outcomes (ITMOs) trade –embedded in the market mechanisms of Article 6 of the Paris Agreement– in assisting countries to achieve their Nationally Determined Contributions (NDCs), incentivize increased mitigation ambition, and contribute to the long-term goals of the Paris Agreement. The study takes place within a context characterized by highly heterogeneous and non-Paris aligned NDCs, reflecting current global circumstances. The study employs a conceptual framework that integrates the Social Cost of Carbon (SCC), Marginal Abatement Cost (MAC) curves, and Marginal Benefit (MB) curves. This framework is used to analyze the impact of ITMO trading on the ambition of NDCs and the potential for global mitigation. The research reveals that the roles countries play in the ITMO market—whether as buyers or sellers—is significantly influenced by the varied nature of NDCs, each country’s unique domestic marginal abatement costs, and how their mitigation ambition aligns with the SCC. In addition, it was found that ITMO trading can potentially trigger additional mitigation and escalate target ambitions. However, the success of this mechanism heavily depends on certain conditions, restrictions, and alignment with Article 6 principles. For instance, allowing negative reoptimization could lead to countries manipulating their NDCs for short-term gain, thus undermining long-term climate goals. In contrast, scenarios permitting positive reoptimization and restricting trade to beyond-NDC targets can encourage higher ambition levels in line with the Paris Agreement goals. However, the study also highlighted significant challenges and limitations. The risk of overselling could undermine future mitigation efforts, and managing these complexities requires a thorough understanding of each country’s domestic mitigation context. Moreover, the varied nature of NDCs adds a layer of complexity to ITMO trading, necessitating a meticulous examination of each country’s future actions. The study recommends future research to devise methods for better aligning NDCs to facilitate more effective ITMO trading. This could involve an extensive exploration of potential safeguards for ITMO trade such as transfer limits, ambition coefficients, surplus targets, and taxes. Evaluating their effectiveness could offer valuable policy implications for ITMO trade regulation. Future studies should also delve into the uncertainties and dynamic intertemporal effects that impact ITMO trading, aspects not accounted for in the current conceptual framework. By broadening the focus to include imperfect markets and real-world uncertainties, we can strive towards more robust and effective climate policies.
  • Peters, Olubusola (2023)
    We assessed the association between hair cortisol concentration (HCC), a biomarker for long-term stress, and pre-schoolers’ diet on the macronutrient level in this cross-sectional study. The data was collected in 2015-16 from a population of 655 Finnish children of ages 3-6 years. Hair samples of 2cm from the scalp were collected to represent the HCC from the past two months. Macronutrient intake was examined using food diaries filled out by the parents and Early childhood education and Care (ECEC) on behalf of the pre-schoolers. For the socioeconomic status (SES) the parents reported their highest education level reached and family income. We evaluated the association between the pre-schoolers’ HCC and energy percentage (E%) macronutrient intake with univariate and multiple linear regression models. We evaluated three models which we adjusted for varying confounders; Model 1 had no adjustments, model 2 was adjusted with the ISO BMI and energy intake (KJ) and Model 3 had further adjustments with the highest education level and the relative household monthly income. There was no association found between the pre-schoolers’ HCC and macronutrient intake. Our results are in line with a previous study which also assessed the association between HCC and macronutrient intake in E% but not in g/day. Further studies are needed to gain a deeper understanding of the relationship between HCC and macronutrient intake in young children.
  • Lehtimäki, Janina (2023)
    Various disturbances of varying durations can occur in production lines. Objective of this master´s thesis was to research how disturbances in production lines possibly affect the microbiological and sensory quality of the product. The study examined products that had been standing at room temperature for 0, 30, 60 and 210 minutes. These samples were examined at time points 0, 20, 40 and 60 days. Three different batches were used for the sampling purposes. In the microbiology section contaminating microbes, yeast, molds, enterobacteriaceae and lactic acid bacteria were studied. The identification of colonies was performed using the Maldi-TOF method. For the sensory study, evaluations were conducted at the company factory using difference-from-control method. The aim of sensory study was to determine whether temperature fluctuations alter the sensory quality. A total of 29 participants took part in the sensory study. The participants discovered variation between samples and the fluctuations in temperature did cause growth in contaminating microbes and lactic acid bacteria on the culture media. However, there was no significant growth observed in molds and yeasts. No enterobacteriaceae were detected during the research. In the sensory study, the evaluators did not find significant differences between reference sample and sample which was exposed to room temperature for 30 minutes. The results did not support the hypothesis of the sensory aspect of this thesis. It should be noted that possible greater number of participants or different sensory research method could have revealed more information. Overall, the research revealed information about the effects of temperature on cheese, particularly the crucial time frame within which cheese can be kept at room temperature before quality deteriorates. The results indicate that temperature variations during processing phase have impact on the overall quality. Furthermore, the study confirmed the absence of harmful bacteria and highlighted that temperature fluctuations influence the sensory quality especially in terms of the product´s appearance.