Spectroscopy of Deep Traps in Cu2S-CdS Junction Structures

Cu2S-CdS junctions of the polycrystalline material layers have been examined by combining the capacitance deep level transient spectroscopy technique together with white LED light additional illumination (C-DLTS-WL) and the photo-ionization spectroscopy (PIS) implemented by the photocurrent probing. Three types of junction structures, separated by using the barrier capacitance characteristics of the junctions and correlated with XRD distinguished precipitates of the polycrystalline layers, exhibit different deep trap spectra within CdS substrates

Downscaling the in vitro test of fungal bioremediation of polycyclic aromatic hydrocarbons : methodological approach

ISSN 1618-2650 (Online)The miniaturization and optimization of a white rot fungal bioremediation experiment is described in this paper. The optimized procedure allows determination of the degradation kinetics of anthracene. The miniaturized procedure requires only 2.5 ml of culture medium. The experiment is more precise, robust, and better controlled comparing it to classical tests in flasks. Using this technique, different parts, i.e., the culture medium, the fungi, and the cotton seal, can be analyzed. A simple sample preparation speeds up the analytical process. Experiments performed show degradation of anthracene up to approximately 60 % by Irpex lacteus and up to approximately 40 % by Pleurotus ostreatus in 25 days. Bioremediation of anthracene by the consortium of I. lacteus and P. ostreatus shows the biodegradation of anthracene up to approximately 56 % in 23 days. At the end of the experiment, the surface tension of culture medium decreased comparing it to the blank, indicating generation of surfactant compoundsBiochemijos katedraBotanikos sodasInstrumentinės analizės APCKauno technologijos universitetasVytauto Didžiojo universiteta

Isolation and identification of fungi tolerant to polycyclic aromatic hydrocarbons and coal tar from different habitats in Lithuania

(Impact Factor: 0.825), eISSN: 1029-0486A group of 36 fungal strains, belonging to the Lithuanian Mycobiota, was collected and isolated from different locations, habitats and matrices, including creosote treated wood in storage yards for crosstie wastes. The 8 most perspective strains selected according to preliminary assessment of tolerance to coal tar were subsequently identified combining taxonomical evaluation and molecular techniques. The tolerance of the 8 identified fungal species (5 basidiomycetes and 3 ascomycetes) to the presence of various concentrations of coal tar, and for the 4 most perspective fungal strains (Pleurotus sp., Schizophyllum sp., Irpex lacteus, Bjerkandera adusta) to polycyclic aromatic hydrocarbons. The ligninolytic enzymatic activity assay of the isolated strains resulted in a good correspondence between the tolerance to pollutants and the capability to produce ligninolytic enzymes indicating, that this group of white-rot fungi is perspective for further investigation and eventual usage for mycoremediation of polycyclic aromatic hydrocarbons polluted substratesBiochemijos katedraBotanikos sodasInstrumentinės analizės APCKauno technologijos universitetasVytauto Didžiojo universiteta

Portable Photometer for Enzymatic Measurements in situ

Miniaturized instruments offer a possibility of using them in situ. Such approach in (bio)chemical analysis greatly reduces the time needed for an analytical task, because no sample transportation is needed resulting in faster analytical process and possibility to spoil the sample is reduced. In this work, previously developed miniaturized colorimeter has been upgraded [1]. Using the designed system, the enzymatic activity has been determined following previously published procedure [2]. The fungi were grown according to the previously optimized downscaled format [3]. In this work a design of miniaturized photometer and application determining laccase activity in malt extract fermentation medium will be discussedBiochemijos katedraFitopatologijos grupėGamtos mokslų fakultetasInstrumentinės analizės APCJSC Biocentras, PagiriaiVytauto Didžiojo universiteta

Fitoremedijacija tiriant žolinius augalus ir jų rizosferos mikroorganizmus subostate – naudotų pabėgių medienos pjuvenų mišinyje su dirvožemiu tręšiamu azotu

Tyrimai atlikti 2013–2014 metais augalų vegetacijos metu sukurtame bandyme ex situ, auginant penkių rūšių augalus vegetaciniuose induose su užterštu naudotų medinių pabėgių pjuvenomis ir neužterštu substratu tręšiamu azoto trąšomis. Tyrimų tikslas – ištirti žolinių augalų antžeminės ir požeminės dalių morfologinių savybių ir šių augalų rizosferoje grybų bei bakterijų kolonijų skaičiaus priklausomybę nuo substrato taršalų ir azoto trąšų koncentracijos poveikio; tuo pagrindu nustatyti šių augalų tinkamumą fitoremediacijai. Nustatyta tolerantiškas augalas t.y. fitoremediatorius Tagetes patula L, prisitaikęs augti užteršto ir azotu tręšiamo substrato sąlygomis bei tinkamas auginimui analogiškomis edafinėmis sąlygomis. Netolerantiškas augalas, t.y. fitoindikatorius, yra Trifolium repens L. – Fabaceae Lindl. šeimos daugiametis, žolinis augalas, kurio rizosferoje yra maksimalus grybų ir bakterijų kolonijų skaičius, esant maksimalioms azoto trąšų ir teršalų koncentracijoms. Šie bakteriologiniai ir mikologiniai procesai bei azoto perteklius neigiamai veikia Trifolium repens L. antžeminės ir požeminės dalių augimąThe studies were carried out in the period of 2013–2014 in an ex situ experiment developed during plant vegetation, cultivating 5 plant species in vegetative pots with a substrate contaminated with used sleepers and an uncontaminated substrate fertilised by nitrogenous fertilisers. The objective of the research was to analyse the morphological features of aboveground and underground parts of herbaceous plants and determine the dependence between the number of fungi and bacteria colonies in the rhizosphere of these plants and substrate contaminants and the impact of nitrogenous fertiliser concentration; with reference to that, to determine the feasibility of these plants for phytoremediation. A tolerant plant, i.e., Tagetes patula L. as a phytoremediator, which adapted to grow in the condition of a contaminated substrate fertilised by nitrogen and suitable for cultivating it in similar edaphic conditions, was used. An intolerant plant, i.e., Trifolium repens L. as a phytoindicator, is a perennial, herbaceous plant of Fabaceae Lindl. family, the rhizosphere of which contains the maximum number of fungi and bacteria colonies in the occurrence of the maximum concentration of nitrogenous fertilisers and contaminants. These bacteriological and mycological processes, as well as the excess of nitrogen, have a negative impact on the growth of aboveground and underground parts of Trifolium repensBiochemijos katedraBotanikos sodasFitopatologijos grupėInstrumentinės analizės APCKauno technologijos universitetasVytauto Didžiojo universiteta

Influence of creosote-polluted substrate on the bioremediation-potential microscopic fungi in the rhizosphere of plants

Wooden sleepers used in railways are impregnated with preservatives with fungicidic and bactericidic properties, which contain a large amount of harmful polycyclic aromatic hydrocarbons (PAHs). The aim of this research was to reveal the type of fungi in the rhizosphere of plants, which tolerate pollutants and can be involved in bioremediation process of creosote-contaminated used wooden railway sleepers. Tagetes patula grown in the substrate with 12.5% creosote impregnated used wooden sleepers chips additive is characterized by the most intensive root development and the biggest population of active fungi, therefore it is recommended for further investigation. Number of colonies of fungi in the rhizosphere of investigated plants decreased in many cases by increasing the amount of sleepers chips additive in substrate, however it was greater in the substrates with creosote treated wooden sleepers chips additives (12.5, 25 and 37.5% wooden sleepers chips) than in the pure substrate and various substrates with additives of pure Pinus sylvestris chips. This is a pioneering study searching for the local fungi species in Lithuania, which can be further utilized for the bioremediation of PAHsBotanikos sodasFitopatologijos grupėInstrumentinės analizės APCJSC BiocentrasKauno technologijos universitetasVytauto Didžiojo universiteta

Policiklinių aromatinių angliavandenilių, esančių kreozotu apdorotuose mediniuose geležinkelio pabėgiuose, surinktuose skirtingose Lietuvos vietose, sudėties ir kiekio dujų chromatografinė analizė

Atliktas policiklinių aromatinių angliavandenilių (PAA) nustatymas panaudotuose mediniuose geležinkelio pabėgiuose, apdorotuose siekiant juos apsaugoti nuo biologinio irimo skalūnų alyva arba kreozotu. PAA analizei atlikti panaudota skysčių ekstrakcija aplinkos temperatūroje ir Soksleto ekstrakcija bei dujų chromatografija su masių spektrometrine ir liepsnos jonizacijos detekcija. Ekstrakcijai panaudoti skirtingo poliškumo ir aromatiniai organiniai tirpikliai. Rezultatai parodė, kad aromatiniai tirpikliai yra efektyviausi ir lemia didžiausią PAA išgavą, atliekant PAA ekstrakciją iš medienos aplinkos temperatūroje. Buvo identifikuota keletas PAA. Dominavo naftalenas, acenaftenas, fluorenas, antracenas, fenantrenas, fluorantenas, pirenas, krizenas ir benzo[α]antracenas. Išanalizuota 20 Lietuvos centrinėje, ir 30 pajūrio dalyje surinktų bandinių. Panaudojant klasterinės analizės metodą ir cheminės analizės rezultatus bandiniai buvo sugrupuoti pagal keletą veiksnių, įskaitant eksploatacijos trukmę, nusidėvėjimą ir ekstrakto cheminę sudėtį. PAA sudėtis kito priklausomai nuo pabėgių suirimo laipsnio. Keletas pabėgių išsiskyrė iš kitų tamsia išvaizda, intensyviu, būdingu skalūnų alyvai, kvapu ir labai dideliu PAA kiekiuThis paper was presented in the 9th International Conference “The Vital Nature Sign”, held in Kaunas, 14–16 May 2015. The screening of PAH in used wooden railway sleepers treated with coal tar and creosote for their protection against biodegradation has been made. The analysis was based on cold solvent extraction and Soxhlet extraction of PAH using several organic solvents and analysis by GC-MS/GC-FID. For extraction several organic solvents of different polarity, including aromatic solvents, were tested. The results showed that aromatic solvents are the most efficient solvents for cold solvent extraction with the highest recoveries of PAH from wood matrix. Several PAH were identified. Naphthalene, acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene, pyrene, crysene and benzo[α]anthracene were predominant. Thirty samples from Central Lithuania and twenty from the results of chemical analysis the samples were classified using the cluster analysis according to several parameters including age, decay status and chemical composition of the extract of the sleeper. The composition of PAH varies between intact and rotten sleepers. Few sleeper samples differ from others with a strong coal tar odor and a dark color and very high quantities of PAHBiochemijos katedraBiologijos katedraBotanikos sodasKauno technologijos universitetasVytauto Didžiojo universiteta