Browsing by Title
Now showing items 664-683 of 3388
-
(2017)This study examined whether dairy processors and retailers have market power in the Finnish dairy chain, and the analysis was limited to the wholesale and the retail market of dairy products. The study of industrial organization and new empirical industrial organization provided methodological framework for the study. Market power has been extensively studied in other dairy chains but attempts to estimate market power in the Finnish dairy chain are few. Market power in the Finnish dairy chain has not been examined with a bilateral oligopoly approach before. The approach allows relaxing the presumptions about price taking. Because the dairy processing and the retail sector in Finland are highly concentrated, presumptions about price taking would have been too restrictive. The results indicate that retailers have market power over consumers but the wholesale market is competitive. According to the results, retailers employ full mark-up in the retail market, and the market is thus characterized by collusive behavior. A need for further research is emphasized. Because the current evidence is scarce, cumulative evidence through further research would be needed.
-
(2021)Structural complexity of trees is related to various ecological processes and ecosystem services. It can also improve the forests’ ability to adapt to environmental changes. In order to implement the management for complexity and to estimate its functionality, the level of structural complexity must be defined. The fractal-based box dimension (Db) provides an objective and holistic way to define the structural complexity for individual trees. The aim of this study was to compare structural complexity of Scots pine (Pinus sylvestris) trees measured by two remote sensing techniques, namely, terrestrial laser scanning (TLS) and aerial imagery acquired with unmanned aerial vehicle (UAV). Structural complexity for each Scots pine tree (n=2065) was defined by Db-values derived from the TLS and UAV measured point clouds. TLS produced the point clouds directly whereas UAV imagery was converted into point clouds with structure from motion (SfM) technology. The premise was that TLS provides the best available information on Db-values as the point density is higher in TLS than in UAV, and be-cause TLS is able to penetrate vegetation. TLS and UAV measured Db-values were found to significantly differ from each other and, thus, the techniques did not provide comparable information on structural complexity of individual Scots pine trees. On average, UAV measured Db-values were 5% bigger than TLS measured. The divergence between the TLS and UAV measured Db-values was found to be explained by the differences in the number and distribution of the points in the point clouds and by the differences in the estimated tree heights and number of boxes in the box dimension method. Forest structure (two thinning intensities, three thinning types and a control group) significantly affected the variation of both TLS and UAV measured Db-values. However, the divergence between TLS and UAV measured Db-values remained in all the treatments. In terms of the individual tree detection, the number of obtained points in the point cloud, and the distribution of these points, UAV measurements were better when the forest structure was sparser. In conclusion, while aerial imaging is a continuously developing study area and provides many advantageous attributes, at the moment, the TLS methods still dominate in accuracy when measuring the structural complexity at the tree-level. In the future, it should be studied whether TLS and UAV could be used as complementary techniques to provide more accurate and holistic view of the structural complexity in the perspective of both tree- and stand-level.
-
(2020)Despite much scholarly attention given to values and preferences toward the environment, comparatively few studies have examined the spatial relationships between relational values and more established concepts including instrumental and intrinsic values, self-reported knowledge of natural resource management issues, and perceived landscape threats. This study examines these context-based relationships using public participation geographic information systems (PPGIS) survey techniques. An online PPGIS survey was administered during the summer of 2019 to 1,200 residents in Mjölby kommun in Sweden, a community heavily reliant upon silvo-pastoral landscape use. A total of 301 responses were obtained, resulting in a 25.1% response rate. Spatial association and statistical analyses tests were conducted to examine the relationships between different categories of values, self-reported knowledge of natural resource management issues, and values and preferences for landscape threat management. Results indicate that socio-demographics alone have little to no significant impact on how many value points of any category are associated with the environment; however, significant differences in the spatial distribution of values were found by gender and self-reported knowledge of forestry, agriculture, and native biodiversity. Male respondents tended to assign instrumental values in more diverse areas across the landscape. Respondents who rated themselves as knowledgeable about biodiversity tended to assign relational values inside Natura 2000 sites, while those who rated themselves as knowledgeable about forestry avoided placing instrumental values in Natura 2000 sites. Contrary to expectations, instrumental values were the most evenly dispersed across the landscape, while intrinsic values were more concentrated in specific areas, and relational values were the most concentrated around the towns of Mjölby, Skänninge, and Mantorp. High degrees of spatial overlap were found between intrinsic and relational values, implying these value types may be conceptually similar for residents. Future PPGIS research could focus on smaller regions such as those at the municipal or regional level to more precisely identify the context-specific relationships between instrumental, relational and intrinsic values and natural resource management preferences in the local landscape.
-
(2023)Plant-based milks can be unstable during storage due to the colloidal structure of these drinks. In general, e-coded additives are used to increase the viscosity of the drinks and hence, improve stability. Oat beta-glucan, microbially or enzymatically produced exopolysaccharides, such as dextran, and flaxseed mucilage are natural hydrocolloids that are known to have the ability to increase viscosity. These hydrocolloids could potentially be used to replace e-coded additives. The aim of this thesis was to study the stabilizing potential of oat beta-glucan, exopolysaccharides, and flaxseed mucilage in oat drinks. Oat drinks with added hydrocolloids were compared to control samples that were oat drink without added hydrocolloids and oat drinks with pectin at concentrations of 0.2% and 0.4%. Oat beta-glucan, exopolysaccharides, and flaxseed mucilage were added to the prepared drinks by replacing 10% of water with the extracts. Additionally, stabilizing properties of isolated and freeze-dried microbially produced dextran was studied by adding it to the drinks at concentrations of 1.5%, 1.0% and 0.5%. Stability of the oat drinks was assessed during a 14−day storage period by measuring the viscosity, pH, and phase separation. Results of this study demonstrated the stabilizing potential of the natural hydrocolloids. The addition of hydrocolloids increased the viscosity in all samples. The inclusion of natural hydrocolloids led to a similar stability, and in some cases also significantly lower viscosity, compared to pectin added drinks. Oat beta-glucan had a remarkable positive impact on the stability of oat drinks. This was most likely due to the network formation of oat beta-glucan molecules, which decreased the sedimentation of colloidal particles. Enzymatically produced dextran also improved the stability of oat drinks, which might be attributed to the viscosity-increasing -capacity of dextran. However, the stabilizing role of microbially produced exopolysaccharides was not shown. For future study, the molecular interactions of natural hydrocolloids in the colloidal solution should be investigated.
-
(2022)This study was conducted with the participation of HOAS and AYY residents at the two biggest Universities in the Helsinki metropolitan area (HMA), Finland. A total of 187 residents took part in an online survey. The aim of the study is to investigate the association between experiences of nature, environmental identity, and environmental concern. This master’s thesis explores how the experiences of nature (EoN) defined by Clayton and others (2017), as well as the environmental identity, determined by Clayton (2003), were associated with environmental concern. The survey consisted of questions about environmental identity and experiences of nature. The self-estimation about the environmental concern was also taken into consideration. The data were analyzed both via quantitative and qualitative methods, so mixed methods were applied in this study. Factor analysis from multivariate methods was conducted as a part of the quantitative analysis. Content analysis with topic modeling was performed as part of the qualitative analysis. Survey results from the quantitative analysis showed that the residents of HOAS and AYY experience nature mostly as integrated into their daily lives and routines. Yet, the qualitative analysis revealed that more complex nature connections were experienced during vacation times such as leisure time activities (e.g., boating and trekking). Also, experiences of nature are themed under three themes using the results of the factor analysis. Overall, the survey participants were very concerned about the environmental crisis, and they showed a very strong environmental identity. The correlation between EoN and environmental concern was the weakest, and there were stronger correlations between environmental identity and EoN or environmental concern. The result of this study supports Clayton’s (2003) theoretical model that there is a connection between environmental identity and environmental concern.
-
(2019)Non-wood forest products (NWFP) refer to wild berries, mushrooms, herbs and other special NWFPs gathered from forests. Finnish forests have been certified with forest certificates (PEFC and FSC) and as organic wild collection areas. The globally largest organic wild collection areas in Finland have provided organic NWFP raw material for the commercial trade. However, NWFPs are not certified in Finland within forest certificates, unlike in some other European countries. The aim of this study was to collect expert perceptions of NWFP certification, its possible benefits and creation of added-value, and qualifications for applying forest- and organic certificates to NWFP certification. This qualitative study was carried out in thematic interviews to Finnish experts in NWFP and forestry fields. The results indicate that both forest and NWFP experts see the importance of NWFP certification to increase in future. Majority of interviewees appreciate the forest origin as a differentiating factor, which is important to verify. Both expert groups were familiar with organic wild collection areas in Finland. According to experts, the organic wild collection areas are possibility in the exports of NWFPs, though in domestic markets, organic labeled NWFPs rarely create added value for the customers. Majority of interviewees viewed the application of forest certificates to certify NWFPs positively. However, opinions towards it were more divided among the group of forest experts.
-
(2020)The concept of bioeconomy has been harnessed to support societies and their economies to produce value added products from renewable biological resources and to develop circular economy. Such systems require actions from a variety of actors from public and private sectors to consumers. As a heavily forested country Finland’s bioeconomy leans largely on the utilization of forests. Planned pulp and paper industry investments call for end-uses for logs to balance out the wood supply. Both forests and the construction sector are also focal areas in climate change mitigation. Wooden multistorey construction (WMC) and its capability to store carbon has been suggested as a partial solution to the aforementioned issues. The aim of this study is to investigate the relation of WMC and the bioeconomy and the role of end-users in WMC. This explorative study uses qualitative research methods to address its research ques-tions. The data consists of seven focus group interviews conducted in the metropolitan area of Helsinki between September 2017 and February 2019. The interviewed groups, with altogether 26 participants, included an academic expert group, three market actor groups (firm representatives, architects and property managers) and three wooden multistorey resident groups. The residents’ type of housing included rental, owner-occupancy and right-of-occupancy and the buildings were built between 2015 and 2017. Thematization was used for data analysis. Results of the study show that despite Finland’s close-knit relation to its forests and traditions in utiliz-ing wood, WMC is not currently perceived culturally embedded as part of the society nor the construc-tion industry. WMC is still a niche in the country and it also seems more connected to mechanical wood industry than the construction industry. WMC was associated with the bioeconomy by non-resident groups, although experts recognized also potential pitfalls in the current discourse. Percep-tions that were aligned with the general discourse of the bioeconomy are mainly related to material renewability, possibilities to recycle wooden construction material, wood products capabilities to store carbon, and Finland’s relatively abundant forest resources. Despite WMC’s publicly declared role in the bioeconomy programmes, some underlying features make its rationale challenging for consumers, which could turn out to be a hindrance for WMC growth in the future. Generally, experts, firm represent-atives and architects were pro-wood and considered that WMC is still being unjustly stigmatized by various actors. In accordance with previous studies, the interviewed WMC residents were satisfied with their apart-ments and the building as such. A wooden frame does not seem to surpass traditional housing prefer-ences of consumers, but it is perceived as a benefit when choosing housing. Results of this study are much in line with previous findings, which indicate that environmental aspects matter, but not as much as health or other more personal aspects of living. Wood can be sensed in the building and apart-ments, which is perceived positively. However, the prevailing fire safety legislation, which was consid-ered as too strict, constrains the use of wood on visible surfaces in interiors. WMC seems to have an environmentally friendly image among residents, which however calls for better communication.
-
(2024)Trees are the most visible part of urban vegetation, and they provide many ecosystem services which cannot be replaced. The ability to sequester and store carbon (C), balance peaks of storm water flows, regulate microclimate and provide shade in heat waves are dependent on the size and the vitality of a tree. Through the root system, abiotic and biotic factors in growing medium have a role in tree health and size. Tree fine roots and ectomycorrhizal (EcM) root tips, which are the most distal part of root system, have a crucial role in maintenance of tree vitality as they are responsible of water and nutrient uptake. Growing conditions in urban environments differ from those in natural environments. However, urban tree fine roots and EcM root tips are a scarcely studied subject. In this thesis I studied fine root growth, phenology, depth distribution, annual production, and the number of EcM root tips of three different tree species (Tilia cordata, Tilia × europaea and Betula pendula) growing in three different urban greenspaces (park, street site, unmanaged forest patch). In addition, I studied the effect of site, soil temperature, and soil moisture on root elongation. Fine root elongation was observed by a minirhizotron image system below ground from May until November 2020. Root production and the number of EcM root tips was studied by the ingrowth core method. Betula pendula had the highest fine root elongation among the three tree species, which can at least partially be explained by species-specific differences. Growing site had a statistically significant effect on root elongation, but also the thermal sum of soil temperature and the level of relative extractable water affected root elongation. Average height and trunk diameter between Tilias grown at the Garden and Tilias grown at the street side were different relative to their age. Tilias had clearly less EcM root tips on the street side, their fine roots elongated more, and the amount of dead roots was slightly higher than at Garden, indicating that root turnover rate was faster for street trees as they tried to absorb nutrient in a poorer environment. Based on previous studies, differences in fine root elongation between sites were expected, as e.g. rising of the temperature has been found to affect positively to root elongation. Additionally, the poor nutrient status of the growing medium has also previously been found to increase root growth. The site and the characteristics of the growing medium can has a significant effect on the fine roots and thus on the growth and vitality of the entire tree.
-
(2017)Industrial clusters are a worldwide phenomenon and a vital economic development strategy. The approach is defined to be an interrelationship between its participants, suppliers and related industries that produce synergy in a particular location. Clustering has become to be a crucial feature in nation’s economic development. However, the approach has not yet been studied widely in Sub-Saharan African countries and the existing number of empirical studies are limited. Therefore, this leaves a gap for an up-to-date study to investigate the possibilities of developing an efficient forest industry cluster in Angola. The purpose of the study was to critically assess and to define the potential of different wood processing industries in connection to develop an efficient forest industry cluster in the Province of Huambo. The objective was to create a comprehensive picture of the existing market situation through a field study and to develop the future concept of wood processing industries. Research methods were qualitative in the empirical part of the study and quantitative in the investment calculations. The primary data were collected through a semi-structured field interviews and observations of existing operators. Interviews were conducted in January and February 2017 to obtain knowledge about the prevailing market situation and about the existing wood product manufacturers. The data were collected with nine interviews, which were transcribed. Pictures and video clips were recorded to support the observations from the factories in the data collection. Based on the field study and observations, investment alternatives were decided and calculated to different wood processing industries. Profitability of the investments were calculated with the Net Present Value (NPV), Internal Rate of Return (IRR), Multiple of Invested Capital (MOIC) and Wood Paying Capability (WPC) at stumpage. Attention was paid to the uncertainty in the calculations with the help of sensitivity analysis. The literature review was based on the cluster theory, collective efficiency and the capital expenditure projects. As a result of this study, an investment model was developed in a shape of a cluster. The cluster model contains five different dimensions: sustainable plantation forestry, production of primary wood products, production of secondary wood products, wood residues sufficient utilization and production of sustainable energy. This study suggests that veneer peeling and sawn timber production could be selected for the primary wood production, carpentry and furniture for the secondary processing and wood residues to produce sustainable energy. The corresponded 10-year investments NPVs varied from USD 606 000 to USD 974 000 at an interest rate of 15%. The maximum IRR achieved was 31.6% and the minimum was 16.8%. The highest WPC at stumpage achieved was USD 69.8 and the lowest was USD 44.1. The MOIC ranged between 2.4 and 4.0 times the invested capital. This study suggests that the Company could develop an efficient forest industry cluster around veneer peeling with the support from other wood processing industries to the region.
-
(2020)Many European citizens have growing concerns over climate change. This seems to go together with the debate about the impact of consumers’ personal dietary choices on climate change. Novel food protein sources are entering the European food market to replace or compensate meat protein sources. One protein food alternative are insect-based proteins. However, there is limited research as to how choices of alternative insect-based protein products may influence consumers’ carbon footprints. This study explores the potential of insect protein to reduce the carbon footprint associated with European food consumption. Three scenarios were formed to identify and describe options for reducing current levels of carbon footprints associated with the consumption of conventionally produced chicken meat. In the scenarios, soybean meal-based feeds used in conventional chicken production are replaced with insect-based feeds, and chicken products are replaced with protein food products from insects. Further, two different insect feeding sources are considered and compared to each other. A number of existing global warming potential values from a variety of Life Cycle Assessment studies focusing on chicken and insect production were collected to create a database for use in the scenario analyses. The database was utilised to assess the global warming impact of producing alternative insect protein on the carbon footprint of European food consumption. The results from the three scenarios indicate that the carbon footprint of food consumption can be reduced by replacing conventionally produced chicken meat with insect-based protein food products. However, insect-based protein products would have a positive impact on the carbon footprint only if the insects that are produced for use in feed or food are farmed with low-value side streams. Currently, the shift to an increased use of side streams in insect-based food production faces regulatory challenges in Europe. In the light of European efforts to encourage sustainable food alternatives, and considering the environmental benefits insects could offer as alternative proteins over options of conventional protein sources, there is a need for continued research on the environmental sustainability of insect eating and insect feeding, as well as the safety and regulatory issues related to the use of insect protein in food consumption.
-
Exploring the potential of lactic acid bacteria for sensory improvement of plant protein ingredients (2022)One of the greatest challenges of our time is securing the global protein supply for the growing population in a sustainable manner. Fermentation with lactic acid bacteria has a long history of successful employment for the production of fermented foods and beverages. During this study, the ability of diverse lactic acid bacteria for fermentation and sensory improvement of leguminous and cereal protein concentrates was investigated.The main aim of this study was to overcome the sensory limitations of these plant protein ingredients by finding suitable candidates for the design of new starter cultures for their fermentation. A collection of 82 lactic acid bacteria was screened for fermentation of leguminous and cereal protein concentrates with different nutrient supplementations. Most strains required additional nutrients to adequately acidify the leguminous protein concentrate during a 24-h fermentation, while the cereal-based substrate appeared to be a more complete growth substrate. Descriptive sensory analysis also revealed differences in the aroma perceived by a panel depending on the matrix, supplementation and fermenting strain employed. Three of the strains that produced the most desirable aromas and acidified sufficiently the test matrixes were further studied. All three strains preferentially fermented glucose to lactic acid rather than any other sugar. The concentration of hexanal, one of the volatile compounds involved in grassy and beany off-flavor formation, reduced during fermentations in favor of 1-hexanol, a compound with a significantly higher odor threshold. However, only two of the cultures were able to prevent the growth of contaminating bacteria during fermentation. The results of this study can provide guidance for selecting potential starter cultures and fermentation substrate composition to improve the aroma of plant protein ingredients. Two of the selected strains especially have shown potential to be used as starter cultures for the leguminous protein concentrate. Further studies are required to optimize the performance of the selected strains in the test matrixes and to quantitatively characterize their effect on the substrates’ volatile profile, taste and antinutritional factor content
-
(2019)Cameroon is a country located in Central Africa. The country has an export-led economy, which means that the country highly depends on exports to ensure its population well-being. Sawnwood exports represent 14% of Cameroon’s total exports. Sawnwood is therefore one of the most important export products for Cameroon. Since Cameroon signed the EU-Cameroon voluntary partnership agreement policy in 2010, Cameroon’s sawnwood exports were impacted. The aim of this study is therefore, to examine the export competitive performance of Cameroon’s sawnwood industry from 2001 to 2017. Based on the literature, a set of three methods analyzing the competitiveness of Cameroon’s sawnwood exports were chosen. These methods are: The Revealed Comparative Advantage Index (RCA) and RSCA index which were used to analyze the competitiveness and international specialization of Cameroon in exporting sawnwood. The Spearman Rank Correlation was used to study the export competitive performance of Cameroon’s sawnwood across years and to analyze the level of competition between Cameroon, Finland, China and Ghana. Lastly, the Constant Market Share Analysis was used to explain the drivers of Cameroon’s sawnwood export competitiveness. This study also compiles information on forest in Cameroon and provides an overview of Cameroon sawnwood industry, it can therefore serve as a base for further studies on sawnwood in Cameroon. Results show that Cameroon has a competitive advantage and is the highest specialized in exporting sawnwood compared to Finland, China and Ghana. Nevertheless, the export competitive performance of Cameroon across years is not continuous and highly depends on external factors. Results also show that Cameroon has reduced its exports to EU and has diversified its importers portfolio by redirecting its exports trade flows towards Asia, especially China which has less stringent imports policies compared to EU. Cameroon will need to improve its production technologies and management practices to ensure a long run competitiveness on the global sawnwood market.
-
(2020)Norway spruce is commonly cultivated throughout Europe, Russia, and Japan. Cultivation of Norway spruce often faces the issue of fungal diseases, one of which is cherry rust disease caused by Thekopsora areolata. The gene model MA_10g0010 encoding an uncharacterized peroxidase (PabPrx86) has previously been associated with the presence of this pathogen. The aim of this study was to describe and assay the protein produced from this gene model, observe its localization in the cell, and determine its relative expression level in different tissues of Norway spruce. Experiments were performed by isolating the full length cDNA for PabPrx86 and cloning the cDNA into destination vectors pEAQ-HT-DEST1 and pK7FWG2 leading to a hypertranslatable transcript and a C-terminal GFP fusion, respectively. The plasmid constructs were transformed to Agrobacterium tumefaciens and agro-infiltrated to Nicotiana benthamiana. In addition, the relative expression level of this gene in different spruce tissues at different times of the year was determined using the qRT-PCR method. Sequencing showed that there were two allelic variants of this gene in the spruce individual sampled for RNA. Results showed that both alleles code for a peroxidase with basic pI. Subcellular localization with the GFP tag detected that PabPrx86 protein was located out of cytoplasm, indicating that the protein was translated in the ER-ribosomes, whereas relative expression level analysis revealed that PabPrx86 was highest expressed in the bud and lateral bud in June. Peroxidases are known to relate with plant defense, but further experiments are required to determine the role of PabPrx86 in Norway spruce and what the association with T. areolata means.
-
(2023)Membrane-bound pyrophosphatases (M-PPases) catalyse the reversible hydrolysis of pyrophosphate into two inorganic phosphate molecules. This hydrolysis is coupled to the transport of protons and/or sodium ions across the biological membrane, generating an electrochemical gradient, which can be utilized by the host organism as an energy source under different stress conditions. The essential physiological roles of M-PPases in agriculturally relevant plants and various human pathogens, such as Bacteroides fragilis, Plasmodium falciparum, Toxoplasma gondii, and Trypanosoma brucei, make them an important research area. Despite the biochemical studies conducted with several M-PPases and structural characterization of Thermotoga maritima and Vigna radiata M-PPases, there remain several questions regarding the biochemistry and catalytic mechanism of M-PPases, one being the basis of K+ dependence. Mutational studies have suggested that a single residue at position 495 is the sole determinant of K+ dependence in M-PPases. In K+-dependent M-PPases this residue is an alanine and a K+ ion binding in close proximity of it, has been shown of having stimulatory effect on K+- dependent M-PPases by increasing the maximal rate of pyrophosphate hydrolysis. In K+-independent M-PPases, a lysine residue resides at 495 position, where the ε-NH3+ group of the lysine residue has been suggested, based on structural modelling and AlaàLys (A495K) mutational studies, to structurally and functionally mimic the activating function of K+ in K+-dependent M-PPases. In order to provide structural basis to this, in this study, a M-PPase belonging to a hyperthermophilic deep- sea bacterium T. maritima containing a single A495K point mutation was expressed in Saccharomyces cerevisiae, solubilized using the high-temperature (“Hot-solve”) method, purified with metal affinity chromatography and structurally characterized using X-ray crystallography. As suggested, the ε-NH3+ group of the introduced lysine was shown to occupy the same space and form the same interactions at the active site as the K+ ion in K+-dependent M-PPases. However, these structural findings were in contradiction with the conducted hydrolytic activity assay which showed that the A495K mutation, besides abolishing K+ dependence, significantly reduced the overall activity compared to the wild type by ~2-10-fold, depending on the K+ concentration. These findings suggest that additional factor(s) besides the 495 residue determine the K+ dependence in M-PPases.
-
(2019)Finding and developing new antimicrobial compounds against clinically important antimicrobial drug resistant bacterial pathogens is necessary to counter the threats to global health, food security and development caused by these organisms. One potential source for leads for novel antimicrobial agents are bacteriophages, whose genomes hold vast numbers of genes encoding for proteins that are able to inhibit bacteria in yet uncharacterized ways. Characterization of these proteins and their functions is likely to aid the discovery of new antimicrobial drugs. This study aimed to optimize the heterologous production of three bacteria-inhibiting proteins from bacteriophage φR1-RT for the characterization of the proteins and their interactions with the bacterial host cell. Expression plasmids were successfully constructed for the heterologous production of the proteins in both Lactococcus lactis and Escherichia coli -based expression systems. The L. lactis expression system utilized a tightly regulated nisin-controlled promoter and featured a lactococcal SSusp45 secretion leader to target the produced protein to extracellular secretion. The E. coli expression system used a tightly regulated arabinose-inducible promoter to control the expression of the bacteriotoxic proteins. Despite the successful construction of the expression plasmids, the bacteriophage φR1-RT proteins were not able to be produced in quantities suitable for protein purification in either of the expression systems used in this study. The lack of protein expression is likely due to either codon bias or the harmful effects of the bacteriotoxic proteins that build up inside the bacterial cells. Codon optimized genes or a eukaryotic expression system could be tried to produce enough protein for purification and further characterization.
-
(2015)Phytopathogens, notably Heterobasidion annosum, evolved several strategical combinations to infect and subsequently colonize their host even under different stress conditions. Fungal ABC transporters are well-known defenses that can confer resistance against host-secreted secondary metabolites by transporting them outside of the fungal cells and thus keeping their intracellular concentration low. Here, we aim to unveil the evolutionary trajectories of total ABC transporters-encoding genes in Heterobasidion annosum. The gene expression pattern was monitored with the fungus subjected to different chemical stressors and during fungal growth on wood. We identified 32 putative ABC protein-encoding genes in the Heterobasidion genome. Altogether 20 putative ABC transporter-encoding genes of H. annosum were further analyzed and it was revealed that several genes were either up or downregulated, while some were not differentially expressed under the experimental conditions. The results obtained from the gene expression analysis revealed that an ABC gene (annotated as Ha.ABC-G1 or Hetan_66124), was highly up-regulated in most conditions. This particular transporter-encoding gene (Hetan_66124) with induction level of up to 47 –fold (in heartwood and similar levels in other conditions) was traced, PCR amplified, cloned in Escherichia coli and expression of recombinant protein performed using Saccharomyces cerevisiae as platform. Several experiments aiming to dissect functional roles of this hypothetical protein were performed. The growth of the yeast transformant over expressing the recombinant ABC protein in different terpenoids and weak organic acids were monitored. The growth rate of clones with and without transporters were not significantly different when cultured in plates (SC·gal-ura-) that were exposed to the volatile compounds (limonene, carene and ?-pinene). Based on our findings, we concluded that the yeast transformants carrying the H. annosum ABC-G1 transporter encoding gene do not show increased resistance or tolerance against the monoterpenes. The results of the transcript profiling have further contributed to our understanding about gene expression during fungal colonization upon exposure to chemical stressors. However, further studies are needed in order to specifically unveil the functional roles of these efflux pumps that underlie their transport mechanism with response to the host secreted secondary metabolites.
-
(2020)Asteraceae comprises of approximately 10% of all angiosperm plant species. These species are well known for their highly compressed inflorescences known as capitula which consists of morphologically different types of flowers: ray, trans and disc flowers. This immense morphological difference excels Gerbera as an ideal plant to study flower type differentiations. Even though this complex process is governed by several genes, the ray flower identity is believed to be greatly influenced by GhCYC3 promoter mediated gene regulations. In previous studies two TCP transcription factors (TF): GhCIN1and GhCIN2, and two MADS TFs: GAGA1 and RCD5 were identified as the potential upstream regulators of GhCYC3. So, the aim of this study is to test whether these potential upstream regulators physically bind to GhCYC3 promoter in in vitro conditions. In order to achieve the goal, these transcription factor proteins from Gerbera hybrida were successfully expressed in E. coli and purified as fusion proteins to maltose-binding protein (MBP). Physical binding of the purified fusion proteins to the putative target DNA sites in the promoter region of GhCYC3 gene was tested by electrophoretic mobility shift assay (EMSA). The results showed that none of the gerbera transcription factors (GhCIN1, GhCIN2, GAGA1 and RCD5) bind to their putative target sites under the condition tested in this study. However, it might not be justifiable to deduce that these TFs do not interact with GhCYC3 promoter. The absence of in vitro interaction between the tested TFs and GhCYC3 promoter might be caused by either lack of proper folding and activity of the TFs or absence of co-factors which are available in vivo.
-
(2021)Oat β-glucan is well known for its health benefits, which are related to its rheological behavior in the gut. The objective of this thesis was to investigate the extractability and viscosity of β-glucan from oat bread under physiological conditions and to see whether there were varietal differences. Oat flours of twenty different cultivars were used to bake breads which were subjected to in vitro digestion. The resulting extracts were studied for viscosity using a rheometer, and the β-glucan contents of the breads and the extracts were determined to evaluate the extractability. In addition, the effect of flour particle size on extractability was investigated. Variance in the in vitro extractability of β-glucan was seen between cultivars, which was not explained by flour particle size. All samples produced highly viscous extracts, and the viscosities increased sharply with increasing β-glucan concentration, which suggests that the β-glucan was not extensively degraded during the breadmaking process. The viscosities also varied between cultivars, as some exhibited considerably higher viscosities at similar concentrations. The results indicate that the β-glucan from the oat breads would have good capacity to increase viscosity in the intestine, although varietal differences were observed.
-
(2017)Substitution of animal food products and non-biodegradable plastics is of interest for addressing climate change and pollution. Plant proteins are potential raw materials with low environmental impact which can be utilized for development of protein rich foods or biodegradable plastics. Grain legumes and especially lupins are rich in proteins that could be utilized. Protein fibril is a self-assembled non-random protein structure which has a large length to width ratio. The objective of this study was to demonstrate the concept of fibrillating proteins extracted from two lupin species (L. albus and L. angustifolius) and to characterize the formed fibrils. The proteins were extracted from dried and milled lupin seeds with alkaline followed by an isoelectric precipitation. The standard extraction procedure was combined with additional process steps such as dehulling, defatting, extraction with acidic extraction media and dialysis. The extracted protein isolates were hydrolyzed into peptides in different concentrations and assembled into fibrils by heating at pH 2.0 for 24, 48 or 72 h. The fibrillated samples were analyzed with a thioflavin T (ThT) assay to indicate the β-sheet secondary protein structure. Some of the fibrillated samples were imaged with atomic-force microscopy. Samples prepared from dehulled and defatted L. angustifolius flour had the highest total protein content of 98.3 ± 0.4% on dry matter basis. ThT binding was observed in most samples indicating formation of fibrils. The binding increased significantly for samples after standard extraction process and for lower ionic strength. The fibrils appeared to form within 48 h and samples with higher protein concentration (40 mg/ml) showed massive gelation after 24 h. Studying the samples with atomic-force microscopy showed 300 nm long curly fibrils. These initial results indicate that the proteins extracted from lupin can be fibrillated.
-
(2020)New alternatives for meat as the main source of protein are needed due to the negative impact of meat production on the environment and its high utilization of land sources. Vegetable proteins offer a more sustainable choice for meat and they can be processed into a structure that resembles meat using extrusion technology. The aim of this study was to produce a minced meat analogue using extrusion technology. The goal was to gain more information on the textural properties, colour and sensorial features of the meat analogue. In the experimental part, extrudates with replicates were produced from plant protein and fibre concentrate. Three differently processed samples were analysed. Texture analyser was used to measure the gumminess, springiness, chewiness, hardness, adhesiveness and shear energy of the samples. In addition, colour and moisture content were measured and a sensory experiment was conducted. According to the results, the content of the plant protein and fibre concentrate affected the textural properties and the colour of the samples. The results also showed that the composition of minced meat analogue had different effect on the textural properties depending how the sample was processed. In the sensory experiment, the reference sample (minced meat) had significantly higher score of pleasantness compared to extrudate containing samples. No significant differences were observed among the extrudate containing samples. This study showed that a product with some similarities to minced meat can be produced using extrusion technology with plant protein and fibre concentrate. For the development of the meat analogue, a more comprehensive sensory analysis would help to gain more information about the development targets of the product.
Now showing items 664-683 of 3388