Browsing by Subject "219 Environmental biotechnology"

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  • LIU, Jing (2020)
    PART ONE A Review on the Joint International Conference of Nordic Forum of Sino-Western Studies and 20th International Symposium on Bicosmology LIU Jing (Macau University of Science and Technology) From 6th to 7th August 2019, the "2019 International Conference of Nordic Forum of Sino-Western Studies", sponsored by the Nordic Forum of Sino-Western Studies and 20th International Symposium on Biocosmology, was held at the University of Helsinki, Finland. PART TWO A Report on the International Research Project Regarding the Topic of the Impact of Religious Values on Chinese Social Life by JIANG Miao (China Academy of Social Sciences) During the period 20 to 21 August, 2019, a two day workshop titled “The Impact of Religious Values on Chinese Social Life” was held at the Culture Center Sofia, Helsinki, Finland. The workshop was most successful from its commencement, throughout all presentations and session proceedings, and in achievement of its overall goals and objectives.
  • Kemppainen, Petri; Husby, Arild (2018)
    A fundamental assumption in quantitative genetics is that traits are controlled by many loci of small effect. Using genomic data, this assumption can be tested using chromosome partitioning analyses, where the proportion of genetic variance for a trait explained by each chromosome (h(c)(2)), is regressed on its size. However, as h(c)(2)-estimates are necessarily positive (censoring) and the variance increases with chromosome size (heteroscedasticity), two fundamental assumptions of ordinary least squares (OLS) regression are violated. Using simulated and empirical data we demonstrate that these violations lead to incorrect inference of genetic architecture. The degree of bias depends mainly on the number of chromosomes and their size distribution and is therefore specific to the species; using published data across many different species we estimate that not accounting for this effect overall resulted in 28% false positives. We introduce a new and computationally efficient resampling method that corrects for inflation caused by heteroscedasticity and censoring and that works under a large range of dataset sizes and genetic architectures in empirical datasets. Our new method substantially improves the robustness of inferences from chromosome partitioning analyses.
  • Wrzaczek, Michael; Brosche, Mikael; Kollist, Hannes; Kangasjärvi, Jaakko (2009)
    Reactive oxygen species (ROS) have important functions in plant stress responses and development. In plants, ozone and pathogen infection induce an extracellular oxidative burst that is involved in the regulation of cell death. However, very little is known about how plants can perceive ROS and regulate the initiation and the containment of cell death. We have identified an Arabidopsis thaliana protein, GRIM REAPER (GRI), that is involved in the regulation of cell death induced by extracellular ROS. Plants with an insertion in GRI display an ozone-sensitive phenotype. GRI is an Arabidopsis ortholog of the tobacco flower-specific Stig1 gene. The GRI protein appears to be processed in leaves with a release of an N-terminal fragment of the protein. Infiltration of the N-terminal fragment of the GRI protein into leaves caused cell death in a superoxide-and salicylic acid-dependent manner. Analysis of the extracellular GRI protein yields information on how plants can initiate ROS-induced cell death during stress response and development.
  • Biswal, Ajaya K.; Soeno, Kazuo; Gandla, Madhavi Latha; Immerzeel, Peter; Pattathil, Sivakumar; Lucenius, Jessica; Serimaa, Ritva; Hahn, Michael G.; Moritz, Thomas; Jonsson, Leif J.; Israelsson-Nordstrom, Maria; Mellerowicz, Ewa J. (2014)
  • Partanen, Pasi; Hultman, Jenni; Paulin, Lars; Auvinen, Petri; Romantschuk, Martin (2010)
  • Patyshakuliyeva, Aleksandrina; Jurak, Edita; Kohler, Annegret; Baker, Adam; Battaglia, Evy; de Bruijn, Wouter; Burton, Kerry S; Challen, Michael P; Coutinho, Pedro M; Eastwood, Daniel C; Gruben, Birgit S; Mäkelä, Miia; Martin, Francis; Nadal, Marina; van den Brink, Joost; Wiebenga, Ad; Zhou, Miaomiao; Henrissat, Bernard; Kabel, Mirjam; Gruppen, Harry; de Vries, Ronald P (2013)
  • Pakarinen, Annukka; Haven, Mai Ostergaard; Djajadi, Demi Tristan; Varnai, Aniko; Puranen, Terhi; Viikari, Liisa (2014)
  • Benoit, Isabelle; Culleton, Helena; Zhou, Miaomiao; DiFalco, Marcos; Aguilar-Osorio, Guillermo; Battaglia, Evy; Bouzid, Ourdia; Brouwer, Carlo P.J.M; El-Bushari, Hala B.O.; Coutinho, Pedro M.; Gruben, Birgit S.; Hildén, Sari Kristiina; Houbraken, Jos; Jimenez Barboza, Luis Alexis; Levasseur, Anthony; Majoor, Eline; Mäkelä, Miia Riitta; Narang, Hari-Mander; Trejo-Aguilar, Blanca; van den Brink, Joost; vanKuyk, Patricia A; Wiebenga, Ad; McKie, Vincent; McCleary, Barry; Tsang, Adrian; Henrissat, Bernard; de Vries, Ronald P. (2015)
    Background Plant biomass is the major substrate for the production of biofuels and biochemicals, as well as food, textiles and other products. It is also the major carbon source for many fungi and enzymes of these fungi are essential for the depolymerization of plant polysaccharides in industrial processes. This is a highly complex process that involves a large number of extracellular enzymes as well as non-hydrolytic proteins, whose production in fungi is controlled by a set of transcriptional regulators. Aspergillus species form one of the best studied fungal genera in this field, and several species are used for the production of commercial enzyme cocktails. Results It is often assumed that related fungi use similar enzymatic approaches to degrade plant polysaccharides. In this study we have compared the genomic content and the enzymes produced by eight Aspergilli for the degradation of plant biomass. All tested Aspergilli have a similar genomic potential to degrade plant biomass, with the exception of A. clavatus that has a strongly reduced pectinolytic ability. Despite this similar genomic potential their approaches to degrade plant biomass differ markedly in the overall activities as well as the specific enzymes they employ. While many of the genes have orthologs in (nearly) all tested species, only very few of the corresponding enzymes are produced by all species during growth on wheat bran or sugar beet pulp. In addition, significant differences were observed between the enzyme sets produced on these feedstocks, largely correlating with their polysaccharide composition. Conclusions These data demonstrate that Aspergillus species and possibly also other related fungi employ significantly different approaches to degrade plant biomass. This makes sense from an ecological perspective where mixed populations of fungi together degrade plant biomass. The results of this study indicate that combining the approaches from different species could result in improved enzyme mixtures for industrial applications, in particular saccharification of plant biomass for biofuel production. Such an approach may result in a much better improvement of saccharification efficiency than adding specific enzymes to the mixture of a single fungus, which is currently the most common approach used in biotechnology.
  • Tossavainen, Marika; Nykänen, Anne; Valkonen, Kalle Santeri; Ojala, Anne; Silja, Kostia; Romantschuk, Martin (2017)
    Growth and fatty acid production of microalga Selenastrum sp. with associated bacteria was studied in lab-scale experiments in three composting leachate liquids. Nutrient reduction in cultures was measured at different initial substrate strengths. A small, pilot-scale photobioreactor (PBR) was used to verify labscale results. Similar growth conditions supported growth of both Selenastrum and bacteria. CO2 feed enhanced the production of biomass and lipids in PBR (2.4 g L-1 and 17% DW) compared to lab-scale (0.1-1.6 g L-1 and 4.0-6.5% DW) experiments. Also prolonged cultivation time increased lipid content in PBR. At both scales, NH4-N with an initial concentration of ca. 40 mg L-1 was completely removed from the biowaste leachate. In lab-scale, maximal COD reduction was over 2000 mg L-1, indicating mixotrophic growth of Selenastrum. Co-cultures are efficient in composting leachate liquid treatment, and conversion of waste to biomass is a promising approach to improve the bioeconomy of composting plants. (C) 2017 The Authors. Published by Elsevier Ltd.
  • Mikola, Juha; Setälä, Heikki; Virkajärvi, P; Saarijärvi, K; Ilmarinen, K; Voigt, W; Vestberg, M (2009)
    Large herbivores can influence plant and soil properties in grassland ecosystems, but especially for belowground biota and processes, the mechanisms that explain these effects are not fully understood. Here, we examine the capability of three grazing mechanisms-plant defoliation, dung and urine return, and physical presence of animals (causing trampling and excreta return in patches)-to explain grazing effects in Phleum pratense-Festuca pratensis dairy cow pasture in Finland. Comparison of control plots and plots grazed by cows showed that grazing maintained original plant-community structure, decreased shoot mass and root N and P concentrations, increased shoot N and P concentrations, and had an inconsistent effect on root mass. Among soil fauna, grazing increased the abundance of fungivorous nematodes and Aporrectodea earthworms and decreased the abundance of detritivorous enchytraeids and Lumbricus earthworms. Grazing also increased soil density and pH but did not affect average soil inorganic-N concentration. To reveal the mechanisms behind these effects, we analyzed results from mowed plots and plots that were both mowed and treated with a dung and urine mixture. This comparison revealed that grazing effects on plant attributes were almost entirely explained by defoliation, with only one partly explained by excreta return. Among belowground attributes, however, the mechanisms were more mixed, with effects explained by defoliation, patchy excreta return, and cow trampling. Average soil inorganic-N concentration was not affected by grazing because it was simultaneously decreased by defoliation and increased by cow presence. Presence of cows created great spatial heterogeneity in soil N availability and abundance of fungivorous nematodes. A greenhouse trial revealed a grazing-induced soil feedback on plant growth, which was explained by patchiness in N availability rather than changes in soil biota. Our results show that grazing effects on plant attributes can be satisfactorily predicted using the effects of defoliation, whereas those on soil fauna and soil N availability need understanding of other mechanisms as well. The results indicate that defoliation-induced changes in plant ecophysiology and the great spatial variation in N availability created by grazers are the two key mechanisms through which large herbivores can control grassland ecosystems.
  • Takala, Ninni; Siren, Heli; Jakl, Michal; Dytrtová, Jana Jaklová (2019)
    The azoles (represented by penconazole, cyproconazole, and tebuconazole in this study) are frequently used agrochemicals to protect various crops against mildew and fungi. They are considered as endocrine disruptors, because they block the biosynthesis (on the level of enzymes inhibition) of biochemicals with steroid structure. Besides targeted impacts, they can partly get into the soil with the rainfall or litter fall and influence/block the biosynthesis of sterols of non-target organisms. In this sense, the risk of disruption of rhizosphere plant-microbial symbiosis and dynamic processes in the soil solution by azoles is of high importance to be evaluated. We have developed an analytical methodology for determination of penconazole, cyproconazole, and tebuconazole in soil solution using capillary electrophoresis with a photodiode array detector at UV-214 nm and acidic electrolyte solution (pH 1.48). The results were also compared with mass spectrometric measurements using mu-TOF mass spectrometry. There approx. 90% of present azoles were bound in the soil solution matrix. The detection limit for these azoles is about 10(-7) mol dm(-3). Because of very low pK(a) of azoles, we have to consider deprotonation of azoles and consequently the high affinity to create complexes with cations. The majority of present azoles in soil solution might form neutral adducts with mono-cations, making them invisible in electrospray mass spectra. [GRAPHICS] .
  • Isojärvi, J.; Shunmugam, S.; Sivonen, Anna Kaarina; Allahverdiyeva, Yagut; Aro, Eva-Mari; Battchikova, Natalia (2015)
    We announce the draft genome sequence of Calothrix strain 336/3, an N2-fixing heterocystous filamentous cyanobacterium isolated from a natural habitat. Calothrix 336/3 produces higher levels of hydrogen than Nostoc punctiforme PCC 73102 and Anabaena strain PCC 7120 and, therefore, is of interest for potential technological applications.
  • Varnai, Aniko; Costa, Thales H. F.; Faulds, Craig B.; Milagres, Adriane M. F.; Siika-aho, Matti; Ferraz, Andre (2014)
    Background: Sugar cane internodes can be divided diagonally into four fractions, of which the two innermost ones are the least recalcitrant pith and the moderately accessible pith-rind interface. These fractions differ in enzymatic hydrolyzability due to structural differences. In general, cellulose hydrolysis in plants is hindered by its physical interaction with hemicellulose and lignin. Lignin is believed to be linked covalently to hemicellulose through hydroxycinnamic acids, forming a compact matrix around the polysaccharides. Acetyl xylan esterase and three feruloyl esterases were evaluated for their potential to fragment the lignocellulosic network in sugar cane and to indirectly increase the accessibility of cellulose. Results: The hydrolyzability of the pith and pith-rind interface fractions of a low-lignin-containing sugar cane clone (H58) was compared to that of a reference cultivar (RC). Acetyl xylan esterase enhanced the rate and overall yield of cellulose and xylan hydrolysis in all four substrates. Of the three feruloyl esterases tested, only TsFaeC was capable of releasing p-coumaric acid, while AnFaeA and NcFaeD released ferulic acid from both the pith and interface fractions. Ferulic acid release was higher from the less recalcitrant clone (H58)/fraction (pith), whereas more p-coumaric acid was released from the clone (RC)/fraction (interface) with a higher lignin content. In addition, a compositional analysis of the four fractions revealed that p-coumaroyl content correlated with lignin, while feruloyl content correlated with arabinose content, suggesting different esterification patterns of these two hydroxycinnamic acids. Despite the extensive release of phenolic acids, feruloyl esterases only moderately promoted enzyme access to cellulose or xylan. Conclusions: Acetyl xylan esterase TrAXE was more efficient in enhancing the overall saccharification of sugar cane, compared to the feruloyl esterases AnFaeA, TsFaeC, and NcFaeD. The hydroxycinnamic acid composition of sugar cane fractions and the hydrolysis data together suggest that feruloyl groups are more likely to decorate xylan, while p-coumaroyl groups are rather linked to lignin. The three different feruloyl esterases had distinct product profiles on non-pretreated sugar cane substrate, indicating that sugar cane pith could function as a possible natural substrate for feruloyl esterase activity measurements. Hydrolysis data suggest that TsFaeC was able to release p-coumaroyl groups esterifying lignin.
  • Lundell, Taina Kristina; Bentley, Elodie; Hilden, Sari Kristiina; Rytioja, Johanna Tuulikki; Kuuskeri, Jaana Tuulia; Ufot, Usenobong F.; Nousiainen, Paula Annukka; Hofrichter, Martin; Wahlsten, Matti Per-Vilhelm; Doyle, Wendy; Smith, Andrew T. (2017)
    Background. Manganese peroxidases (MnP) and lignin peroxidases (LiP) are haem-including fungal secreted class-II peroxidases, which are interesting oxidoreductases in protein engineering aimed at design of biocatalysts for lignin and lignocellulose conversion, dye compound degradation, activation of aromatic compounds, and biofuel production. Objective. Recombinant short-type MnP (Pr-MnP3) of the white rot fungus Phlebia radiata, and its manganese-binding site (E40, E44, D186) directed variants were produced and characterized. To allow catalytic applications, enzymatic bleaching of Reactive Blue 5 and conversion of lignin-like compounds by engineered class-II peroxidases were explored. Method. Pr-MnP3 and its variants were expressed in Escherichia coli. The resultant body proteins were lysed, purified and refolded into haem-including enzymes in 6-7% protein recovery, and examined spectroscopically and kinetically. Results. Successful production of active enzymes was attained, with spectral characteristics of high-spin class-II peroxidases. Recombinant Pr-MnP3 demonstrated high affinity to Mn2+, which was noticeably affected by single (D186H/N) and double (E40H+E44H) mutations. Without addition of Mn2+, Pr-MnP3 was able to oxidize ABTS and decolorize Reactive Blue 5. Pc-LiPH8, its Trp-radical site variants, and engineered CiP-LiP demonstrated conversion of veratryl alcohol and dimeric non-phenolic lignin-model compounds (arylglycerol-β-aryl ethers) with production of veratraldehyde, which is evidence for cation radical formation with subsequent Cα-Cβ cleavage. Pc-LiPH8 and CiP variants were able to effectively oxidize and convert the phenolic dimer (guaiacylglycerol-β–guaiacyl ether). Conclusion. Our results demonstrate suitability of engineered MnP and LiP peroxidases for dye-decolorizing, and efficiency of LiP and its variants for activation and degradation of phenolic and non-phenolic lignin-like aryl ether-linked compounds.
  • Österman, Janina Maria; Mousavi, Seyed Abdollah; Koskinen, Jani Patrik; Paulin, Lars Göran; Lindström, Anna Kristina (2015)
    Background The symbiotic phenotype of Neorhizobium galegae, with strains specifically fixing nitrogen with either Galega orientalis or G. officinalis, has made it a target in research on determinants of host specificity in nitrogen fixation. The genomic differences between representative strains of the two symbiovars are, however, relatively small. This introduced a need for a dataset representing a larger bacterial population in order to make better conclusions on characteristics typical for a subset of the species. In this study, we produced draft genomes of eight strains of N. galegae having different symbiotic phenotypes, both with regard to host specificity and nitrogen fixation efficiency. These genomes were analysed together with the previously published complete genomes of N. galegae strains HAMBI 540T and HAMBI 1141. Results The results showed that the presence of an additional rpoN sigma factor gene in the symbiosis gene region is a characteristic specific to symbiovar orientalis, required for nitrogen fixation. Also the nifQ gene was shown to be crucial for functional symbiosis in both symbiovars. Genome-wide analyses identified additional genes characteristic of strains of the same symbiovar and of strains having similar plant growth promoting properties on Galega orientalis. Many of these genes are involved in transcriptional regulation or in metabolic functions. Conclusions The results of this study confirm that the only symbiosis-related gene that is present in one symbiovar of N. galegae but not in the other is an rpoN gene. The specific function of this gene remains to be determined, however. New genes that were identified as specific for strains of one symbiovar may be involved in determining host specificity, while others are defined as potential determinant genes for differences in efficiency of nitrogen fixation.
  • Gerling, Claudia; Doppler, Thomas; Heyd, Volker; Knipper, Corina; Kuhn, Thomas; Lehmann, Moritz F.; Pike, Alistair W. G.; Schibler, Jorg (2017)
  • Szijarto, Nora; Siika-Aho, Matti; Sontag-Strohm, Tuula; Viikari, Liisa (2011)