Screening and Identification of Trichoderma Strains Isolated from Natural Habitats with Potential to Cellulose and Xylan Degrading Enzymes Production

A total of 123 Trichoderma strains were isolated from different habitats and tested for their ability to degrade cellulose and xylan by simple plate screening method. Among strains, more than 34 and 45% respectively, exhibited higher cellulolytic and xylanolytic activity, compared to the reference strain T. reesei QM 9414. For strains efficiently degrading cellulose, a highest enzyme activity was confirmed using filter paper test, and it resulted in a range from 1.01 to 7.15 FPU/ml. Based on morphological and molecular analysis, the isolates were identified as Trichoderma. The most frequently identified strains belonged to Trichoderma harzianum species. Among all strains, the most effective in degradation of cellulose and xylose was T. harzianum and T. virens, especially those isolated from forest wood, forest soil or garden and mushroom compost. The results of this work confirmed that numerous strains from the Trichoderma species have high cellulose and xylan degradation potential and could be useful for lignocellulose biomass conversion e.g. for biofuel production

Biological Denitrification of High Nitrate Processing Wastewaters from Explosives Production Plant

Wastewater samples originating from an explosives production plant (3,000 mg N l−1 nitrate, 4.8 mg l−1 nitroglycerin, 1.9 mg l−1 nitroglycol and 1,200 mg l−1 chemical oxygen demand) were subjected to biological purification. An attempt to completely remove nitrate and to decrease the chemical oxygen demand was carried out under anaerobic conditions. A soil isolated microbial consortium capable of biodegrading various organic compounds and reduce nitrate to atmospheric nitrogen under anaerobic conditions was used. Complete removal of nitrates with simultaneous elimination of nitroglycerin and ethylene glycol dinitrate (nitroglycol) was achieved as a result of the conducted research. Specific nitrate reduction rate was estimated at 12.3 mg N g−1 VSS h−1. Toxicity of wastewater samples during the denitrification process was studied by measuring the activity of dehydrogenases in the activated sludge. Mutagenicity was determined by employing the Ames test. The maximum mutagenic activity did not exceed 0.5. The obtained results suggest that the studied wastewater samples did not exhibit mutagenic properties

Not Just a Pot: Visual Episodic Memory in Cannabis Users and Polydrug Cannabis Users: ROC and ERP Preliminary Investigation

Background While research has consistently identified an association between long-term cannabis use and memory impairments, few studies have examined this relationship in a polydrug context (i.e., when combining cannabis with other substances).Aims: In this preliminary study, we used event-related potentials to examine the recognition process in a visual episodic memory task in cannabis users (CU) and cannabis polydrug users (PU). We hypothesized that CU and PU will have both–behavioral and psychophysiological–indicators of memory processes affected, compared to matched non-using controls with the PU expressing more severe changes.Methods 29 non-using controls (CG), 24 CU and 27 PU were enrolled into the study. All participants completed a visual learning recognition task while brain electrical activity was recorded. Event-related potentials were calculated for familiar (old) and new images from a signal recorded during a subsequent recognition test. We used receiver operating characteristic curves for behavioral data analysis.Results The groups did not differ in memory performance based on receiver operating characteristic method in accuracy and discriminability indicators nor mean reaction times for old/new images. The frontal old/new effect expected from prior research was observed for all participants, while a parietal old/new effect was not observed. While, the significant differences in the late parietal component (LPC) amplitude was observed between CG and PU but not between CG and CU nor CU and PU. Linear regression analysis was used to examine the mean amplitude of the LPC component as a predictor of memory performance accuracy indicator. LPC amplitude predicts recognition accuracy only in the CG.Conclusion The results showed alterations in recognition memory processing in CU and PU groups compared to CG, which were not manifested on the behavioral level, and were the most prominent in cannabis polydrug users. We interpret it as a manifestation of the cumulative effect of multiple drug usage in the PU group

Biodiversity of soil bacteria exposed to sub-lethal concentrations of phosphonium-based ionic liquids: Effects of toxicity and biodegradation

Little is known about the effect of ionic liquids (ILs) on the structure of soil microbial communities and resulting biodiversity. Therefore, we studied the influence of six trihexyl(tetradecyl)phosphonium ILs (with either bromide or various organic anions) at sublethal concentrations on the structure of microbial community present in an urban park soil in 100-day microcosm experiments. The biodiversity decreased in all samples (Shannon's index decreased from 1.75 down to 0.74 and OTU's number decreased from 1399 down to 965) with the largest decrease observed in the microcosms spiked with ILs where biodegradation extent was higher than 80%. (i.e. [P66614][Br] and [P66614][2,4,4]). Despite this general decrease in biodiversity, which can be explained by ecotoxic effect of the ILs, the microbial community in the microcosms was enriched with Gram-negative hydrocarbon-degrading genera e.g. Sphingomonas. It is hypothesized that, in addition to toxicity, the observed decrease in biodiversity and change in the microbial community structure may be explained by the primary biodegradation of the ILs or their metabolites by the mentioned genera, which outcompeted other microorganisms unable to degrade ILs or their metabolites. Thus, the introduction of phosphonium-based ILs into soils at sub-lethal concentrations may result not only in a decrease in biodiversity due to toxic effects, but also in enrichment with ILs-degrading bacteria

Composting of briquetted tobacco dust

W pracy przedstawiono wyniki badań nad efektywnością zagospodarowania zbrykietowanego pyłu tytoniowego w procesie kompostowania z dojrzałym kompostem (z komunalnego osadu ściekowego i słomy pszennej) i świeżym osadem czynnym po stabilizacji tlenowej. Celem badań było określenie możliwości uzyskania stabilnego kompostu z przeznaczeniem na cele nieprzemysłowe oraz sprawdzenie tempa rozkładu zbrykietowanego pyłu tytoniowego charakteryzującego się bardzo dużą twardością. Doświadczenie obejmowało dwie pryzmy kompostowe i prowadzone było przez pięć miesięcy. Na podstawie przeprowadzonych badań stwierdzono, iż proces kompostowania odpadu tytoniowego z dojrzałym kompostem i osadem ściekowym w przyjętych proporcjach stosunku C:N stanowi korzystną alternatywę zagospodarowania tego odpadu w stosunku do dotychczas stosowanych metod.This study undertook investigations on the elaboration and determination of the utilization efficiency of briquetted tobacco dust in the composting process using mature compost (with municipal sewage sludge and wheat straw) and fresh municipal aerobic sewage sludge. The objective of performed investigations was to ascertain possibilities of obtain of a stable compost intended for non-industrial purposes and to check up on rate of biodegradation of briquetted tobacco dust characterized by exceptional hardness. The experiment comprised two compost piles and was conducted for five months. The performed studies indicated, that composting of tobacco waste with mature compost and sewage sludge in estimated C:N ratio is advisable alternative of this waste management to till now using methods

Biodegradation of wastes from oil industry by composting process

Celem pracy było zbadanie możliwości biodegradacji odpadu z przemysłu tłuszczowego charakteryzującego się bardzo dużą zawartością substancji tłuszczowych (57%) oraz wynikającą stąd mazistą konsystencją. Proces kompostowania prowadzono w warunkach tlenowych metodą pryzmową w trzech niezależnie, jednocześnie przygotowanych stosach kompostowych. Warunkiem skuteczności prowadzonego procesu było polepszenie właściwości fizycznych wyżej wspomnianego odpadu poprzez dobranie odpowiedniego materiału strukturotwórczego stwarzającego warunki tlenowe dla prawidłowego funkcjonowania mikroorganizmów odpowiedzialnych za rozkład substancji tłuszczowych. Istotne znaczenie w przeprowadzonych badaniach odegrało ustalenie odpowiedniej wilgotności pryzm kompostowych na początku procesu (w zakresie 60–75%) w celu zapewnienia odpowiedniej aktywności wodnej dla rozwoju mikroorganizmów i zainicjowania wytwarzania metabolitów przez bakterie mezofilne, które ulegając utlenieniu zainicjowały wytworzenie dużej ilości ciepła, a tym samym gwałtowny wzrost temperatury w pryzmach już w trzeciej dobie do 40°C, a następnie osiągnięcie temperatury maksymalnej (60°C) w dwunastej dobie i utrzymywanie się zakresu temperaturowego 50–57°C przez kolejne 15 dni. Ustalone optymalne wilgotności i proporcje materiałów do skomponowania stosów kompostowych przyczyniły się do ustalenia również właściwego pH wewnątrz stosów kompostowych w zakresie pH 6,5 do 7,5, co przy niekorzystnej wartości pH = 3 odpadu podlegającego biodegradacji czyli zaolejonej ziemi bielącej, stanowiło niebagatelny problem na początku procesu. Konsekwencją intensywnie przebiegającego procesu mineralizacji wyrażonego wzrostem temperatury były ilościowe zmiany węgla i azotu ogólnego prowadzące z kolei do systematycznego zmniejszania się wartości stosunku C:N z 29:1 do 15:1 po 6 miesiącach kompostowania. W gotowym kompoście zawartość substancji tłuszczowych wynosiła 9,1 g•kg-1s.s., która to wartość nie obniża wartości nawozowej uzyskanego kompostu.The aim of the study was to investigate biodegradability of fat industry waste, characterized by very high contents of fatty substances (57%) and the resulting greasy consistency. The composting process was run under aerobic conditions using the compost heap method in three independent, simultaneously prepared compost heaps. A necessary pre-condition to ensure the effectiveness of the conducted process was to improve physical properties of the above mentioned waste by selecting an appropriate structure-forming material, providing aerobic conditions for the adequate functioning of microorganisms responsible for decomposition of fatty substances. In the conducted investigations it was essential to determine adequate moisture content of compost heaps at the beginning of the process (ranging from 60 to 75%) in order to provide appropriate water activity for the development of microorganisms and initiation of metabolite production by mesophilous bacteria, which when oxidized initiated generation of large amounts of heat, and thus a rapid increase in temperature in heaps already at the third day to 40°C, and next reaching the maximum temperature (60°C) at day 12, and the maintenance of the temperature range of 50–57°C for the next 15 days. Determined optimal moisture contents and proportions of component materials for compost heaps contributed additionally to the determination of appropriate pH inside compost heaps to be within the range of 6.5 to 7.5, which at the adverse value pH = 3 of the biodegradable waste, i.e. oiled fuller's earth, constituted a serious problem at the beginning of the process. The intensive mineralization process, manifested in an increase in temperature, resulted in quantitative changes in carbon and total nitrogen, leading in turn to a regular decrease in the values of the C:N ratio ration from 29:1 to 15:1 was reduced. The content of fat substances was 9,1 g·kg-1d.m in mature compost. That concentration of fat not reduce organic value of prepared compost