DOI: 10.22364/eeb.15.07 ABSTRACTS OF THE 75th SCIENTIFIC CONFERENCE OF THE UNIVERSITY OF LATVIA January – February 2017 Lazdiņa L., Obuka V., Nikolajeva V. The antimicrobial effect of modified clay materials 49 Pormale J., Osvalde A., Kursule A. First results of research on cloudberry Rubus chamaemorus in Latvia 50 Ievinsh G. Effect of different salts on growth and physiological charateristics of Secale cereale seedlings: a possible relationship with ethylene 51 Andersone-Ozola U., Gaile L., Ievinsh G. Response of European protected species Dianthus arenarius subsp. arenarius to trampling and sand burial in controlled conditions 53 Gaile L., Ievinsh G. Possible effect of storage conditions on concentration of photosynthetic pigments in bryophyte samples 55 Gaile L., Andersone-Ozola U., Samsone I., Ievinsh G. Physiological changes of rare coastal species Plantago maritima due to extreme substrate salinity 56 Dūmiņš K., Andersone-Ozola U., Samsone I., Ņečajeva J., Ievinsh G. Effect of cocultivation of related species on abiotic and biotic responses: the first results from the Trifolium study 57 Kirsteina A., Lu I.-N., Farinelle S., Muller C., Tars K., Kazaks A. Expression, purification and immunological properties of influenza hemagglutinin peptides 59 Poppels A. Structural changes of macrozoobenthoss communities after Venta river rapid stage “Ventas rumba” restoration 61 Rābante L., Dokane K. Dynamics of the quantitative photosynthesis indicators in field beans (Vicia faba) induced by zinc accumulation 62 Ņečajeva J., Erdmane J. Seed dormancy in different wild oat populations in Latgale and Vidzeme 63 Plikshs M., Pilāts V. Seal influence on costal fishery in Latvia: a case study 65 Druvietis I. Macroscopic green algae from genus Cladophora in freshwaters of Latvia 67 Šiliņš R., Kokorīte I., Reihmanis J., Druvietis I. Impact of the growing population of great cormorant Phalacrocorax carbo on the trophic status of Lake Engure 69 Druvietis I., Dobkeviča L., Dunke M. Peculiarities of phytoplankton communities in urban lakes of Riga City and its vicinity 71 Alksne L. Fast cefotaxime resistance diagnosis in Enterobacteriaceae using MALDI-TOF 73 Fokina O., Krasņevska N., Boiko D., Grauda D., Rashal I. Opportunity of using mobile genetic elements for the study of genetic diversity of natural populations 75 Jakovele A., Petrovska I., Trofimova J., Avsejenko J. Investigation of virulence genes, serogroups and antibiotic resistance of Escherichia coli isolated from food and livestock 77 Jekabsone J. Large river phytoplankton index and its relationships with environmental factors 79 Environmental and Experimental Biology ISSN 2255-9582 47 Ošiņa K., Rostoka E., Sjakste N. Effects of AV-153-Ca on expression of genes related to DNA repair and nitric oxide metabolism in kidneys of rats with alloxan induced diabetes mellitus 80 Krasņevska N., Grauda D., Rashal I. Endopolyploidy of Ligularia sibirica leaves at different development stages 81 Kuļikova I., Boikova E., Petrovics N. Heavy metals and oxidative stress levels in macrophytes in different regions of the Baltic Sea 83 Grauda D., Belogrudova I., Salmane I., Krasņevska N., Avotiņš K., Kolodinska Brantestam A., Boiko D., Fokina O., Rashal I. Ecological aspect of the investigations of genetic diversity of species 85 Kalneniece K., Bērziņš A., Petriņa Z., Ruģele K., Salava E., Eglītis A., Grūbe M., Nikolajeva V., Mutere O. Autoclaving as an effective pre-treatment for enzymatic hydrolysis of wood 86 Okmane L., Matjuškova N., Nāgele Z., Zaļā D., Poppele I. Effect of a maple leaf additive on growth of Lentinula edodes 87 Marcinkevica D., Miezitis J., Makarenkova G. Purification of Penicillium lanoso-viride AMP deaminase by column chromatography 89 Salmane I., Reimane L., Minova S., Jankevica L. Prophylactic use of predator and parasitoid complex to control pest populations in polycarbonate greenhouses in Latvia 91 Grantiņa-Ieviņa L., Rostoks N., Ieviņa B., Evelone V. Evaluation of potential risks of genetically modified seeds and plant propagating material to enter the territory of Latvia 93 Environmental and Experimental Biology (2017) 15: 49 Abstract of the 75th Scientific Conference of the University of Latvia The antimicrobial effect of modified clay materials Linda Lazdiņa1*, Vaira Obuka2, Vizma Nikolajeva1 1Faculty of Biology, University of Latvia, Jelgavas 1, Riga LV–1004, Latvia 2Faculty of Geography and Earth Sciences, University of Latvia, Jelgavas 1, Riga LV–1004, Latvia *Corresponding author, E-mail: [email protected] Key words: clay, antimicrobial effect, fungi. Clay is one of the most common sedimentary rocks in References world and also in Latvia. The spectrum of clay application Andersen B., Frisvad J.C., Søndergaard I., Rasmussen I.S., Larsen is very wide, it is used in construction, cosmetics and other L.S. 2011. Associations between fungal species and water- production sectors, but only a few clay types have natural damaged building materials. Appl. Environ. Microbiol. 77: 4180–4188. anti-microbial activity (Haydel et al. 2008). So the research Bagherabadi S., Zafari D., Soleimani M.J. 2015. Genetic diversity of new antimicrobial additives is important because it of Alternaria alternata isolates causing potato brown leaf spot, would not only enhance the application of clay in the areas using ISSR markers in Iran. J. Plant Pathol. Microbiol. 6: 286. where it is already used, but would help to discover new Haydel S.E., Remenih C.M., Williams L.N. 2008. Broad-spectrum aspects of use. in vitro antibacterial activities of clay minerals against Cladosporium herbarum and Alternaria alternata are antibiotic-susceptible and antibiotic-resistant bacterial saprophytic fungi. These species are very common and pathogens. J. Antimicrob. Chemother. 61: 353–361. often contaminate air. In natural conditions they are found Schubert K., Groenewald J.Z., Braun U., Dijksterhuis J., Starink M., in many substrates – in composites, plant debris, soil, in Hill C.F., Zalar P., de Hoog G.S., Crous P.W. 2007. Biodiversity in the Cladosporium herbarum complex (Davidiellaceae, wood materials and they are also plant pathogens. In indoor Capnodiales), with standardisation of methods for conditions they develop on foodstuffs, textiles, walls and Cladosporium taxonomy and diagnostics. Stud. Mycol. 258: elsewhere (Schubert et al. 2007; Bagherabadi et al. 2015). 105–156. Fungi from both Cladosporium and Alternaria genera are allergic agents. Since they are able to grow on the walls, their elimination is important not only from a medical point of view, but also from the point of view of preservation of cultural heritage. The major fungal growth is observed in buildings with high relative humidity. Nowadays 15 to 40% of North Americans and Northern Europeans encounter mould growth in indoor conditions (Andersen et al. 2011). Malt extract agar medium was prepared for this study. Four different modified clay powders from LLC Baltic Clay Minerals where added to 0.2 and 2.0% concentration. One half of media were infected with Cladosporium herbarum, other half with Alternaria alternata. Plates were incubated at room temperature and results were assessed after seven days. Antimicrobial effect was observed in three of the four tested samples. (Fig. 1). A. alternata and C. herbarum growth analyses were also performed on potential composite construction materials, containing modified additives. Fig. 1. Control plates and plates with modified clay powder number 2. A, B, C – Cladosporium herbarum; D, E, F – Alternaria Acknowledgements alternata; A, D – control samples without clay powder; B, E – medium with modified clay powder, contains 0.2% clay; C, F – We would like to thank LLC Baltic Clay Minerals for the given medium with modified clay powder contains 2.0% clay. opportunity to work with modified clay materials. 49 Environmental and Experimental Biology (2017) 15: 50 Abstract of the 75th Scientific Conference of the University of Latvia First results of research on cloudberry Rubus chamaemorus in Latvia Jolanta Pormale*, Anita Osvalde, Anita Kursule Institute of Biology, University of Latvia, Miera 3, Salaspils, Latvia *Corresponding author, E-mail: [email protected] Key words: cloudberry, cultivation, mineral nutrition, Rubus chamaemorus. Cloudberry (Rubus chamaemorus L.) is a perennial species in cloudberry soil was more similar to cranberry growing with a boreal circumpolar distribution. It is widespread in medium, but a level of nutrients in leaves was similar to North America, and in Europe it is found mainly in Russia, that in blueberries. Further studies are necessary to reveal Norway, Finland (Thiem 2003). Cloudberries grow mostly in specificity of cloudberry mineral nutrition in natural peaty moors and bogs in mountains, in acidic and nutrient- populations. poor soils. Specific species biology (Korpelainen 1994) is Our second task was to start the development of basic the main challenge for scientists as well as for growers: (1) principles for cultivation technology of hermaphroditic about 95% of plant biomass is allocated to underground cloudberry cultivar ‘Nyby’, corresponding to soil and climate and only 5% to sexual reproduction, (2) complicated conditions in Latvia. Field experiment was established in pollination related to unisexuality in cloudberries is serious farm Strelnieki, autumn 2014, with seedlings of cloudberry obstacle for cultivation due to different time of flowering cultivar 'Nyby'. Different fertilization treatments were and unfavourable proportion of female and male plants. used