Biological and chemical contamination of illegal, uncontrolled refuse storage areas in Poland.

This study focused on assessing the microbiological and chemical contamination of air, soil and leachate in uncontrolled refuse storage areas in central Poland. The research included an analysis of the number of microorganisms (culture method), endotoxin concentration (gas chromatography-mass spectrometry), heavy metals level (atomic absorption spectrometry), elemental characteristics (elemental analyser), cytotoxicity assessment against A-549 (human lung) and Caco-2 (human colon adenocarcinoma) cell lines (PrestoBlue™ test) and toxic compound identification (ultra-high-performance liquid chromatography-quadrupole time-of-flight ultrahigh-resolution mass spectrometry). Microbial contamination differed depending on the dump and the group of tested microorganisms. The number of bacteria was: 4.3 × 102 - 1.8 × 103 CFU m-3 (air); 1.1 × 103 - 1.2 × 106 CFU mL-1 (leachate); 1.0 × 106 - 3.9 × 106 CFU g-1 (soil). Respectively, for air and soil the number of fungi was: 2.2 × 102 - 4.6 × 102 CFU m-3; 1.8 × 102 - 3.9 × 103 CFU g-1. Metal levels (Fe, Mn, Pb, Zn, Al, Hg, Cd, Cu, Cr) were higher than in the control sample; however, the average concentrations did not exceed the permissible standards. The cytotoxicity of soil and leachate samples depended on the dump, sample and cell line tested. The leachates were more cytotoxic than soil extracts. Compounds belonging to pesticides, surfactants and biocides, chemicals and/or polymer degradation products, medicinal drugs and insect repellents were found. The detection of potential pathogens in the air, soil and leachate, the presence of toxic compounds and the confirmation of the cytotoxic effect of leachate and soil on human cell lines justify the need for further research on the risks posed by illegal dumps. These studies should aim at developing a unified assessment method and a method to minimise the risk of contaminants spreading in the environment, including harmful biological agents.

Multi-Analytical Techniques for the Study of Burial Clothes of Polish King Sigismund III Vasa (1566-1633) and His Wife Constance Habsburg (1588-1631).

The subjects of this research are the burial clothes of Polish King Sigismund III Vasa and his wife Constance, which were woven and embroidered with silk and metal threads. Fragments of the textiles underwent spectroscopic, spectrometric, and thermogravimetric analyses. The hydrofluoric acid extraction method was improved to isolate various classes of dyes from the textile samples that had direct contact with human remains. High-performance liquid chromatography, coupled with diode array and tandem mass spectrometry detectors with electrospray ionization (HPLC-DAD-ESI-MS/MS) facilitated the detection and identification of colorants present in the textiles. Cochineal, indigo-, madder-, orchil-, and tannin-producing plants were identified as the sources of dyes used. Scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDS) was employed to identify and characterize the silk fibers and mordants and the metal threads. The presence of iron, aluminum, sodium, and calcium in the silk threads suggests their potential use as mordants. The analysis of the metal threads revealed that most of them were made from flattened gilded silver wire, with only a few being cut from a sheet of metal. Typical degradation mechanisms of metal threads were shown, resulting from both burial environment and earlier manufacturing process, and the use of the textiles in clothing, i.e., a significant loss of the gold layer was observed in most of silver gilt threads, caused by abrasion and delamination. The results of the thermal analysis confirmed the presence of silk and silver threads in the examined textiles.

Assessment of Physicochemical, Microbiological and Toxicological Hazards at an Illegal Landfill in Central Poland.

This study aimed to assess the physicochemical, microbiological and toxicological hazards at an illegal landfill in central Poland. The research included the analysis of airborne dust (laser photometer), the number of microorganisms in the air, soil and leachate (culture method) and the microbial diversity in the landfill environment (high-throughput sequencing on the Illumina Miseq); the cytotoxicity (PrestoBlue) and genotoxicity (alkaline comet assay) of soil and leachate were tested. Moreover, an analysis of UHPLC-Q-ToF-UHRMS (ultra-high-performance liquid chromatography-quadrupole-time-of-flight ultrahigh-resolution mass spectrometry) was performed to determine the toxic compounds and microbial metabolites. The PM1 dust fraction constituted 99.89% and 99.99% of total dust and exceeded the threshold of 0.025 mg m-3 at the tested locations. In the air, the total number of bacteria was 9.33 × 101-1.11 × 103 CFU m-3, while fungi ranged from 1.17 × 102 to 4.73 × 102 CFU m-3. Psychrophilic bacteria were detected in the largest number in leachates (3.3 × 104 to 2.69 × 106 CFU mL-1) and in soil samples (8.53 × 105 to 1.28 × 106 CFU g-1). Bacteria belonging to Proteobacteria (42-64.7%), Bacteroidetes (4.2-23.7%), Actinobacteria (3.4-19.8%) and Firmicutes (0.7-6.3%) dominated. In the case of fungi, Basidiomycota (23.3-27.7%), Ascomycota (5.6-46.3%) and Mortierellomycota (3.1%) have the highest abundance. Bacteria (Bacillus, Clostridium, Cellulosimicrobium, Escherichia, Pseudomonas) and fungi (Microascus, Chrysosporium, Candida, Malassezia, Aspergillus, Alternaria, Fusarium, Stachybotrys, Cladosporium, Didymella) that are potentially hazardous to human health were detected in samples collected from the landfill. Tested leachates and soils were characterised by varied cyto/genotoxins. Common pesticides (carbamazepine, prometryn, terbutryn, permethrin, carbanilide, pyrethrin, carbaryl and prallethrin), quaternary ammonium compounds (benzalkonium chlorides), chemicals and/or polymer degradation products (melamine, triphenylphosphate, diphenylphtalate, insect repellent diethyltoluamide, and drugs (ketoprofen)) were found in soil and leachate samples. It has been proven that the tested landfill is the source of the emission of particulate matter; microorganisms (including potential pathogens) and cyto/genotoxic compounds.

Thermosensitive chitosan gels containing calcium glycerophosphate.

In this paper the properties of thermosensitive chitosan hydrogels, formulated with chitosan chloride with ß-glycerophosphate disodium salt hydrate and chitosan chloride with ß-glycerophosphate disodium salt hydrate enriched with calcium glycerophosphate, are presented. The study focused on the determination of the hydrogel structure after conditioning in water. The structure of the gels was investigated by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The crystallinity of the gel structure was determined by X-ray diffraction analysis (XRD) and the thermal effects were determined based on DSC thermograms.

Rheo-Kinetic Study of Sol-Gel Phase Transition of Chitosan Colloidal Systems.

Chitosan colloidal systems, created by dispersing in aqueous solutions of hydrochloric acid, with and without the addition of disodium ß-glycerophosphate (ß-NaGP), were prepared for the investigation of forming mechanisms of chitosan hydrogels. Three types of chitosan were used in varying molecular weights. The impacts of the charge and shape of the macromolecules on the phase transition process were assessed. The chitosan system without the addition of ß-NaGP was characterized by stiff and entangled molecules, in contrast to the chitosan system with the addition of ß-NaGP, wherein the molecules adopt a more flexible and disentangled form. Differences in molecules shapes were confirmed using the Zeta potential and thixotropy experiments. The chitosan system without ß-NaGP revealed a rapid nature of phase transition-consistent with diffusion-limited aggregation (DLA). The chitosan system with ß-NaGP revealed a two-step nature of phase transition, wherein the first step was consistent with reaction-limited aggregation (RLA), while the second step complied with diffusion-limited aggregation (DLA).

Prebiotics and age, but not probiotics affect the transformation of 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ) by fecal microbiota - An in vitro study.

Heterocyclic aromatic amines (HAAs) are carcinogens which are formed in meat cooked using high-temperature methods. The human gastrointestinal (GI) microbiota plays a crucial role in maintaining health in humans of different ages, and especially in the elderly. However, the GI microbiota, whose metabolism and composition changes with age, may also be responsible for the activation of mutagenic substances reaching the colon with diet. Probiotics and prebiotics are promising in terms of reducing the destructive effects of HAAs. The aim of the study was to determine if fecal microbiota derived from the feces of 27 volunteers: infants (up to 18 months), adults (aged 23-39 years), the sub-elderly (aged 64-65 years), and the elderly (aged 76-87 years), and the presence of probiotics or prebiotics, affected the transformation of IQ (2-amino-3-methylimidazo[4,5-f]quinoline) to 7-OH-IQ (2-amino-3,6-dihydro-3-methyl-7H-imidazo[4,5-f]quinoline-7-one). The compounds were identified using LC-MS(n), NMR, and FTIR. Their genotoxicity was compared in the comet assay. Individual strains capable of IQ transformation were also identified. 7-OH-IQ was detected in six persons (two children and four elderly individuals). The degree of IQ conversion ranged from 26% (4-month-old girl) to 94% (81-year-old woman) of the initial quantity. Four Enterococcus isolates: two Enterococcus faecium and two Enterococcus faecalis strains, as well as one Clostridium difficile strain (LOCK 1030, from the culture collection) converted IQ to 7-OH-IQ. The genotoxicity of samples containing 7-OH-IQ was even three times higher (P < 0.05) than those with IQ and was correlated with the degree of IQ conversion and 7-OH-IQ concentration.

Probiotic lactic acid bacteria detoxify N-nitrosodimethylamine.

Humans can be exposed to N-nitroso compounds (NOCs) due to many environmental sources, as well as endogenous formation. The main nitrosamine found in food products and also synthesised in vivo by intestinal microbiota is N-nitrosodimethylamine (NDMA). It can cause cancer of the stomach, kidney and colon. The effect of four probiotic Lactobacillus strains on NDMA was studied under different culture conditions (24 h in MRS, 168 h in modified MRS N, and 168 h in phosphate buffer). HPLC and GC-TEA methods were used for NDMA determination in supernatants. The influence of lactic acid bacteria on NDMA genotoxicity was investigated by means of the comet assay. Additionally, the effect of NDMA (2-100 µg ml⁻¹) on the growth and survival of the probiotic strains was studied. The results indicate that the bacteria decreased NDMA concentration by up to 50%, depending on the culture conditions, time of incubation, NDMA concentration, pH and bacterial strain. Lb. brevis 0945 lowered the concentration and genotoxicity of NDMA most effectively by up to 50%. This could be due to either adsorption or metabolism. The growth and survival of the bacteria was not affected by any of the tested NDMA concentrations.

Unusual thermal stability of RNA/[RP-PS]-DNA/RNA triplexes containing a homopurine DNA strand.

Homopurine deoxyribonucleoside phosphorothioates, as short as hexanucleotides and possessing all internucleotide linkages of RP configuration, form a triple helix with two RNA or 2'-OMe-RNA strands, with Watson-Crick and Hoogsteen complementarity. Melting temperature and fluorescence quenching experiments strongly suggest that the Hoogsteen RNA strand is parallel to the homopurine [RP-PS]-oligomer. Remarkably, these triplexes are thermally more stable than complexes formed by unmodified homopurine DNA molecules of the same sequence. The triplexes formed by phosphorothioate DNA dodecamers containing 4-6 dG residues are thermally stable at pH 7.4, although their stability increases significantly at pH 5.3. FTIR measurements suggest participation of the C2-carbonyl group of the pyrimidines in the stabilization of the triplex structure. Formation of triple-helix complexes with exogenously delivered PS-oligos may become useful for the reduction of RNA accessibility in vivo and, hence, selective suppression/inhibition of the translation process.

Influence of N,N-bis(3-aminopropyl)dodecylamine on the mycelium growth and the cell wall composition of resistance and sensitive strains belonging to the genus Aspergillus.

Resistance causes of moulds to N,N-bis(3-aminopropyl)dodecylamine (APDA) for selected species of Aspergillus niger and Aspergillus flavus was examined. Control (sensitive) strains and resistant strains, cultured at 0.05% triamine, were used in the experiments. The non-resistant strains did not have growth capacity in this amount of ADPA while the resistant strains were characterised by a smaller biomass increase. Individual stages of the development of the mycelium occurred later than those in the control samples. The participation of the cell wall in the mycelium biomass of the resistant strains was higher by 7.5%. The glucan content in the wall dry mass was lower by 11% than that in the sensitive strains. A 41% increase in the lipid content was recorded in the cell wall of resistant Aspergillus flavus. A 21% protein increase occurred in the wall of Aspergillus niger comparing to the control strain. Infrared spectrophotometric analysis of the cell wall did not reveal the presence of triamine. Most absorption bands disappeared in the wall of Aspergillus flavus while no additional absorption bands were registered in Aspergillus niger; some bands were only stronger than those in the control sample. The resistant strains were characterised by a smaller ergosterol content, the main constituent of cell membranes. Spectrophotometric analysis of the mycelium did not reveal significant qualitative changes; only quantitative changes were observed. It was noticed that the resistance reaction did not occur with the same intensity in both species studied. The resistant strain of Aspergillus niger was characterised by a slightly more intensive absorption within its entire spectrum range in comparison to control strain. In case of Aspergillus flavus the absorption was higher for control strain.