Ecotoxicity and fungal deterioration of recycled polypropylene/wood composites: Effect of wood content and coupling

Polypropylene (PP)/wood composites were produced by homogenization in a twin-screw extruder and injection molding of tensile bars. Their mechanical properties were determined before and after exposure to biological treatment, and the effect of the treatment was assessed by various ways including visual inspection and the measurement of weight loss. The ecotoxicity of the materials was also evaluated by using the bioluminescent bacteria Vibrio fischeri. The results proved that wood facilitates biodeterioration (colonization) under the conditions used. The coupling agents do not have inhibitory effect, but seems to stimulate fungal growth (biodeterioration) at large loads of wood flour. PP/wood composites can be considered quite durable, but the influence of wood content on environmental resistance must be taken into account for materials intended for applications requiring long-term outdoor exposure as the time of exposure to microbial colonization increases. Direct ecotoxic effect on aquatic ecosystems cannot be expected from PP/wood composites

Influence of mitosporic fungi upon zinc-polymeric coatings on steel under the different environment

Zinc-polymeric coating samples were exposed to different environmental conditions (for 2 years): marine – dunes on the shore of the Baltic Sea (Neringa), rural-agrarian district of Moletai and the industrial zone of Vilnius. During the whole period of the study 94 species of fungi, were isolated from the exposed samples of zinc-polymeric coating on steel. The zinc-polymeric coatings exposed to marine and rural-agrarian environments were deteriorated most markedly. A scanning electron microscope (SEM) was used to characterize the morphology of the surface. The phase composition of the zinc-polymeric coatings on the steel substrate was analysed by an X-ray diffractometer (XRD). The products formed on the zinc-polymeric coatings were detected by a Fourier transformation infrared spectrometer (FTIR). The effect of environmental conditions on the mass change of the samples was determined by the standard dissolution method. First published online: 08 Feb 201

Use of Brassica Plants in the Phytoremediation and Biofumigation Processes

In recent decades, serious contamination of soils by heavy metals has been reported. It is therefore a matter of urgency to develop a new and efficient technology for removing contaminants from soil. Another aspect to this problem is that environmental pollution decreases the biological quality of soil, which is why pesticides and fertilizers are being used in ever-larger quantities. The environmentally friendly solutions to these problems are phytoremediation, which is a technology that cleanses the soil of heavy metals, and biofumigation, a process that helps to protect crops using natural plant compounds. So far, these methods have only been used separately; however, research on a technology that combines them both using white cabbage has been carried out

Polyphasic taxonomy of Aspergillus section Candidi based on molecular, morphological and physiological data

Aspergillus section Candidi historically included a single white-spored species, A. candidus. Later studies clarified that other species may also belong to this section. In this study, we examined isolates of species tentatively assigned to section Candidi using a polyphasic approach. The characters examined include sequence analysis of partial β-tubulin, calmodulin and ITS sequences of the isolates, morphological and physiological tests, and examination of the extrolite profiles. Our data indicate that the revised section Candidi includes 4 species: A. candidus, A. campestris, A. taichungensis and A. tritici. This is strongly supported by all the morphological characteristics that are characteristic of section Candidi: slow growing colonies with globose conidial heads having white to yellowish conidia, conidiophores smooth, small conidiophores common, metulae present and covering the entire vesicle, some large Aspergillus heads with large metulae, presence of diminutive heads in all species, conidia smooth or nearly so with a subglobose to ovoid shape, and the presence of sclerotia in three species (A. candidus, A. taichungensis and A. tritici). Aspergillus tritici has been suggested to be the synonym of A. candidus previously, however, sequence data indicate that this is a valid species and includes isolates came from soil, wheat grain, flour and drums from India, Ghana, Sweden, The Netherlands and Hungary, making it a relatively widespread species. All species produce terphenyllins and candidusins and three species (A. candidus, A. campestris and A. tritici) produce chlorflavonins. Xanthoascins have only been found in A. candidus. Each of the species in section Candidi produce several other species specific extrolites, and none of these have been found in any other Aspergillus species. A. candidus has often been listed as a human pathogenic species, but this is unlikely as this species cannot grow at 37 °C. The pathogenic species may be A. tritici or white mutants of Aspergillus flavus

Microbiological destruction of constructional and decoration materials of buildings

Factors stimulating the development and spread of micromycetes in buildings used for different purposes were investigated. A variety of materials are used for reconstruction and building: timber, shied-shaped assembled houses, air-entrained concentrate, other local materials, monolithic (expanded clay concrete) houses, large-slab houses, silicate bricks, ceramic building bricks, including special front trim (clinker, restoration, etc.). Resistance of the construction materials to biological factors is not evaluated; the interest is raised only when some concrete damage is encountered. Dampness in buildings is a common reason for a variety of health symptoms in the inhabitants. From inside walls of such buildings the fungi of the Aspergillus genus, mostly A. fumigatus, A. niger, A. penicillioides less frequently of other species were isolated. They are active producers of various metabolites, able to participate in decay processes of various materials. Conditionally pathogenic fungi were found in all the buildings investigated. Their abundance and the variety of species depended on the physical condition of the buildings, their age and the nature of the specific activities which were carried out in them. Keywords: buildings, materials, fungi, destruction, human health

Diversity of Micromycetes in Rhizosphere of Tropical Plants Growing in the Greenhouse of Kaunas Botanical Garden

Darbo tikslas - išskirti ir identifikuoti mikromicetus iš rizosferos augalų, auginamų Kauno botanikos sodo oranžerijos trijose tropinių augalų sekcijose; identifikuoti potencialius augalų šaknų puvinių sukėlėjus. 1996 - 2004 m. atlikus rizosferos mikobiotos tyrimus, išskirta ir identifikuota 112 grybų rūšių, priklausančių 37 gentims, 8 šeimoms, 5 eilėms, 3 klasėms bei 3 skyriams; aprašyta remiantis D. L. Hawksworth et al. (1995) sistema. Didžiąją daugumą identifikuotų izoliatų sudarė mitosporiniai grybai (Mitosporic fungi) - 90 rūšių, priklausančių 27 gentims. Visuose substratuose dominavo Penicillium genties mikromicetai (išskirtos 34 rūšys). Mikromicetų, priklausančių Aspergillus ir Fusarium gentims, iškirta po 8 rūšis, Mucor – 7 rūšys, Mortierella ir Acremonium - po 6. Rečiau buvo aptinkami Trichoderma genties mikromicetai (išskirtos 4 rūšys); Verticillium ir Gliocladium - po 3 rūšis; 28 gentyse – po 1-2 rūšis mikromicetų. Aspergillus fumigatus, A. niger ir Mortierella alpina rūšių mikromicetai buvo aptikti 50-55 proc. tirtų augalų rizosferos; vidutiniškai buvo aptinkamos šios rūšys: Aureobasidium pululans, Mortierella isabellina bei Candida albicans - 19-29 proc. tirtos rizosferos. Išskirtos Fusarium, Verticillium, Pythium ir Sclerotinia genčių mikromicetų rūšys – augalų ligų sukėlėjosBotanikos institutasVytauto Didžiojo universiteta

Fungi in Wooden Houses Build in Vicinity of the Vilnius City

In 2000–2006 mycological condition of wooden buildings used for different purposes in Vilnius has been investigated. From walls, ceilings, various equipment, air, dust micromycetes were isolated and identified; majority of them belong to the Mitosporic fungi group. The degree of their spread and their hazard to the living, working or visiting people are discussed. Improvement of the conditions in the premises is essential because it reduces the hazard of respiratory disorders, asthma, allergies, skin diseases, mycoses, etc. Wooden houses of Vilnius are characterised by specific fungi developing on them. The tests showed that on old balks Daedalea Pers. and Serpula (Pers.) Gray are frequent. They are accompanied by Trichoderma viride, T. harzianum, Penicillium expansum, P. funiculosum, Mucor racemosus, M. strictus, M. hiemalis, Chaetomium globosum, Thamnidium elegans. Serpula lacrymans together with Coniophora puteana, which is also frequent under such conditions, increase the humidity absorbency of brick walls, diminish pH

"Pythium" genties mikromicetai, susiję su vazoniniais augalais

The investigations on ornamental pot-plants of 53 taxa belonging to 38 species, 23 genera, and 8 families were carried out in 1996–2001. The rhizosphere of these plants was investigated, and the microbiological analysis on leaf samples of injured plants was performed. Eight species of the Pythium Pringsh. fungi were isolated; 6 of them were detected for the first time in LithuaniaBotanikos institutasVytauto Didžiojo universiteta

The diversity of micromycete in rhizosphere of plants in different greenhouse selections

1999–2007 m. atlikus Vytauto Didžiojo universiteto Kauno botanikos sodo oranžerijos sekcijose auginamų augalų rizosferos mikologinę analizę, išskirta ir identifikuota 115 mikromicetų rūšių, priklausančių 36 gentims, 3 šeimoms, 3 eilėms, 3 klasėms ir 3 skyriams (aprašyta pagal P. M. Kirk et al. (2001) sistemą). Mažiausiai mikromicetų rūšių išskirta iš vėsiųjų paatogrąžių sekcijos substrato: 43 rūšys, priklausančios 23 gentims, o daugiausiai – iš drėgnųjų atogrąžų sekcijos substrato: 58 rūšys, 19 genčių. Dominavo Penicillium genties grybai, kurių aptikimo dažnis buvo 72 %, įvairovė – 39 rūšys. Rečiau buvo aptinkami Mortierella genties mikromicetai (išskirtos 6 rūšys, 33 %), Aspergillus (8; 29 %), Mucor (7; 23 %), Acremonium (6; 13 %). Išskirti šaknų puvinių ir vytulių sukėlėjai iš Fusarium (7 rūšys), Verticillium (2), Pythium (2) genčiųIn 1999–2007 after the mycological analysis of rhizosphere of plants grown in sections of greenhouses of Kaunas Botanical Garden of Vytautas Magnus University, it was isolated and identified 115 fungi species belonging to 36 genera, 3 families, 3 ranges, 3 classes and 3 divisions (described according to the system of P. M. Kirk et al. (2001)). The least amount of fungi was isolated from substrata of cool subtropic section: 43 species belonging to 23 genera; and the bigest amount – from substrata of humid tropics section: 58 species, 19 genera. Penicillium genus fungi had dominated, it had diversity of 39 species, detection frequency – 72 %. More rarely there were detected Mortierella (isolated 6 species, 33 %), Aspergillus (8; 29 %), Mucor (7; 23%), Acremonium (6; 13 %) genus fungi. There were isolated potential root rot and wilt agents from Fusarium (7 species), Verticillium (2) Pythium (2) genusChemijos institutasVytauto Didžiojo universiteta

Trichoderma viride Pers. against pathogenic microorganisms of Dianthus L

Micromycete Trichoderma viride Pers. strain 113 was selected and used against microorganisms causing pink roots rot Alternaria alternata, Fussarium oxysporum, F. solani, Mortierella isabelina and Verticillium albo atrum. The micromycetes-antagonists inhibited development of those fungi under laboratory conditions. When the antagonist was used for infection with these micromycetes, the negative effect on pink seedlings decreased but did not disappear completely. It became clear that not all the pathogenic fungi were susceptible to Trichoderma viride at the same extent. It was revealed that the positive effect of the antagonist was decreased by Aspergillus fumigatus Fresen., spread widely in substrataBotanikos institutasVytauto Didžiojo universiteta