Microbiological Hazards Associated with Archaeological Works, Illustrated with an Example of Fredro Crypt (Przemyśl, Poland)

The human remains and other materials found in crypts can be highly contaminated with microorganisms. Archaeologists are exposed to microorganisms in many ways (e.g by inhaling dust, contaminating scratches or cuts). We aimed at evaluating microbial hazards associated with human remains and bioaerosols formed during archaeological works in burial crypts. The samples of the human remains, bioaerosols and personal protective equipment (dust respirators, disposable coveralls) were collected during archaeological works in the vault of the Cathedral Basilica of St. John the Baptist and the Assumption of the Blessed Virgin Mary in Przemyśl (Fredro crypt). The microbiological examination involved determining the number of spores of aerobic and anaerobic bacteria, the number of mesophilic and hemolytic bacteria, and the number of xerophilic, non- xerophilic and keratinolytic fungi. The air as well as objects and materials found in crypts are highly contaminated with bacteria and fungi. The xerophilic fungi were the most numerous in all samples of human remains 1–230·103 cfu(colony forming units/g). The non-xerophilic fungi were predominant in bioaerosols (>104 cfu/m3 during archaeological works). The majority of bacterial strains (81.3%) belonged to the genus Bacillus. Fungi belonging to the genera Penicillium (65.2%) and Aspergillus (28.6%) dominated among the isolated fungi. Fogging sterilization of the crypt turned out to be ineffective. The high number of microorganisms both in the air and on human remains indicates that there is a need for particular caution during archaeological works which cause dust emission. In order to reduce exposure to harmful biological factors, the use of disposable personal protective equipment seems necessary

Microbiological Hazards Associated with Archaeological Works, Illustrated with an Example of Fredro Crypt (Przemyśl, Poland)

The human remains and other materials found in crypts can be highly contaminated with microorganisms. Archaeologists are exposed to microorganisms in many ways (e.g by inhaling dust, contaminating scratches or cuts). We aimed at evaluating microbial hazards associated with human remains and bioaerosols formed during archaeological works in burial crypts. The samples of the human remains, bioaerosols and personal protective equipment (dust respirators, disposable coveralls) were collected during archaeological works in the vault of the Cathedral Basilica of St. John the Baptist and the Assumption of the Blessed Virgin Mary in Przemyśl (Fredro crypt). The microbiological examination involved determining the number of spores of aerobic and anaerobic bacteria, the number of mesophilic and hemolytic bacteria, and the number of xerophilic, non- xerophilic and keratinolytic fungi. The air as well as objects and materials found in crypts are highly contaminated with bacteria and fungi. The xerophilic fungi were the most numerous in all samples of human remains 1–230·103 cfu(colony forming units/g). The non-xerophilic fungi were predominant in bioaerosols (>104 cfu/m3 during archaeological works). The majority of bacterial strains (81.3%) belonged to the genus Bacillus. Fungi belonging to the genera Penicillium (65.2%) and Aspergillus (28.6%) dominated among the isolated fungi. Fogging sterilization of the crypt turned out to be ineffective. The high number of microorganisms both in the air and on human remains indicates that there is a need for particular caution during archaeological works which cause dust emission. In order to reduce exposure to harmful biological factors, the use of disposable personal protective equipment seems necessary

Elasticity as the basis of allostery in DNA

Allosteric interactions in DNA are crucial for various biological processes. These interactions are quantified by measuring the change in free energy as a function of the distance between the binding sites for two ligands. Here we show that trends in the interaction energy of ligands binding to DNA can be explained within an elastic birod model. The birod model accounts for the deformation of each strand as well as the change in stacking energy due to perturbations in position and orientation of the bases caused by the binding of ligands. The strain fields produced by the ligands decay with distance from the binding site. The interaction energy of two ligands decays exponentially with the distance between them and oscillates with the periodicity of the double helix in quantitative agreement with experimental measurements. The trend in the computed interaction energy is similar to that in the perturbation of groove width produced by the binding of a single ligand which is consistent with molecular simulations. Our analysis provides a new framework to understand allosteric interactions in DNA and can be extended to other rod-like macromolecules whose elasticity plays a role in biological functions

The role of exochitinase type A1 in the fungistatic activity of the rhizosphere bacterium Paenibacillus sp. M4

The aim of the study was to detect the activity and characterize potentially fungistatic chitinases synthesized by rhizosphere bacteria identified as Paenibacillus sp. M4. Maximum chitinolytic activity was achieved on the fifth day of culturing bacteria in a growth medium with 1% colloidal chitin. Analysis of a zymogram uncovered the presence of four activity bands in the crude bacterial extract. The used three-stage protein purification procedure resulted in a single band of chitinase activity on the zymogram. The purified enzyme exhibited maximum activity at pH 6.5 and temperature 45oC, and thermal stability at 40oC for 4 h. In terms of substrate specificity, it is an exochitinase (chitobiose). The amino acid sequence obtained after mass spectrometry showed similarity to chitinase A1 synthesized by Bacillus circulans. The M4 isolate demonstrated the highest growth inhibiting activity against plant pathogens belonging to the genera Fusarium, Rhizoctonia and Alternaria. Fungistatic activity, although to a somewhat lesser degree, was also demonstrated by purified chitinase. The obtained results confirm the participation of the studied exochitinase in antagonism towards pathogenic molds. However, the lower fungistatic effectiveness of the chitinases points to the synergistic action of different metabolites in biocontrol by these bacteria

The effect of seed bacterization with Bacillus paralicheniformis 2R5 on bacterial and fungal communities in the canola rhizosphere

Bacillus sp. is one of the best-studied plant growth-promoting rhizobacteria (PGPR). However, more detailed studies targeting its effect on the rhizosphere microbial community are required for improving management practices regarding its commercial application in the field. Our earlier study showed that PGPR Bacillus paralicheniformis 2R5 stimulated canola growth. Hence, this study aimed to assess the time-course impact of B. paralicheniformis 2R5 on bacterial and fungal community structure and diversity. The results showed that inoculation with B. paralicheniformis 2R5 initially significantly decreased the observed bacterial richness compared to the control, while after 44 days of treatment this alpha diversity metrics increased. A linear discriminant analysis effect size showed that B. paralicheniformis 2R5 altered the soil bacterial and fungal community structure by increasing the abundance of plants' beneficial microorganisms such as Nitrospira, Ramlibacter, Sphingomonas, Massilia, Terrimonas as well as Solicoccozyma, Schizothecium, Cyphellophora, Fusicolla, Humicola. B. paralicheniformis 2R5 seems to be a promising alternative to chemical pesticides and can be considered for practical application in the field. Its ability to alter the rhizosphere microbiome by increasing the diversity and composition of bacterial communities and increasing plants' beneficial groups of fungi, appears to be important in terms of improving canola development. However, further studies on these increased microbial taxa are necessary to confirm their function in promoting canola growth

The role of hydrophyte systems in sewage treatment from rural areas

Celem badań była ocena skuteczności oczyszczania ścieków bytowo-gospodarczych w małej przydomowej oczyszczalni wierzbowej oraz doczyszczania ścieków w gminnej, mechaniczno-biologicznej oczyszczalni z filtrem piaskowo-trzcinowym. Próbki ścieków do badań pobierano w okresie od maja do grudnia 2007 r. Liczebność bakterii heterotroficznych zdolnych do wzrostu w temperaturze 22°C (jtk 22°C) i 37°C (jtk 37°C) oznaczano metodą płytek lanych zgodnie z normą PN-ISO 6222. Liczebność bakterii z grupy coli (TC) oraz bakterii termotolerancyjnych (fekalnych) z grupy coli (FC) oznaczano metodą fermentacyjną probówkową zgodnie z PN-75/C-04615/05 i PN-77/C-04615/07. Liczebność paciorkowców kałowych [FS] badano metodą filtrów membranowych zgodnie z PN-82/C-04615/25 na podłożu Slanetza-Bertleya. Wykazano znaczne zmniejszenie liczebności większości badanych grup bakterii w trakcie oczyszczania ścieków metodą hydrobotaniczną. W najmniejszym stopniu zmniejszyła się liczebność paciorkowców kałowych.One of the ways to solve the sewage treatment problems in Polish rural areas is the use of unconventional sewage treatment systems based on ponds with macrophytes or on ground filters with hydrophytes. Their function follows the model of natural wetlands. They are featured by many merits and can be used to treat sewage from single farms, small villages, land estates or agro-tourist centres. Beside abiotic processes such as sedimentation and filtration, sorption of chemical pollutants in the medium and photolytic reactions, an important role in sewage treatment play biological factors - vascular flora and microorganisms in a given object. The aim of this study was to assess the effect of sewage treatment in a small home willow treatment plant and treated sewage polishing in the communal mechanical-biological treatment plant with sand-reed filter. The sewage for analyses was sampled from May to December 2007. The number of heterotrophic bacteria capable of growing at temperatures of 22°C (cfu 22°C) and 37°C (cfu 37°C) was estimated by cast plate method according to Polish standard PN-ISO 6222. The numbers of coliform bacteria [TC] and thermo-tolerant (faecal) coliform bacteria [FC] were estimated by means of fermentation test-tube method according to Polish standards PN-75/C-04615/05 and PN-77/C-04615/07. The number of faecal streptococci (FS) was determined by the membrane filter method according to Polish standard PN-82/C-04615/25 with the use of Slanetz-Bertley medium. Considerable reduction of the majority of investigated bacteria groups was found during hydrophyte sewage treatment. The lowest reduction was observed in the number of faecal streptococci

Antimikrobiální účinnost derivátů polyhexamethylenguanidinu inkorporovaných do polykaprolaktonu

The research was aimed at determining the abundance of biofilm formation by Escherichia coli and Staphylococcus aureus on the surface of polycaprolactone (PCL) with polyhexamethylene guanidine (PHMG) derivatives and effect of the derivatives on extracellular hydrolytic enzymes and intracellular dehydrogenases. Biofilm abundance was determined by spectrophotometry, using crystal violet staining. Hydrolytic enzymes after contact with the film were determined with the use of non-specific substrate-fluorscein diacetate. The effect of PHMG derivatives on dehydrogenases activity was assessed using the test, where triphenyltetrazolium chloride (TTC) is reduced to triphenylformazan (TF). The PCL containing PHMG granular polyethylene wax and salt of sulfanilic acid (0.6-1% wt.) strongest inhibited biofilm formation. PHMG derivatives introduced into PCL were found to slightly affect hydrolases activity in both E. coli and S. aureus at a concentration of 0.2 and 0.6%. It was also found that dehydrogenases activity was inhibited by PCL films containing PHMG derivatives. PCL containing 1% of PHMG sulfanilate strongest inhibited hydrolases activity, whereas PCL modified with 1% of PHMG granular polyethylene wax showed the highest inhibitory effect on the activity of both enzymes. W-PCL and A-PCL composites (at concentration of 0.6%) have optimal combination of antibiofilm activity and biodegradability.Výzkum byl zaměřen na určení míry tvorby biofilmu Escherichia coli a Staphylococcus aureus na povrchu polykaprolaktonu (PCL) s deriváty polyhexamethylenguanidinu (PHMG) a účinku derivátů na extracelulární hydrolytické enzymy a intracelulární dehydrogenázy. Množství biofilmu bylo stanoveno spektrofotometrií za použití barvení krystalovou violetí. Hydrolytické enzymy po kontaktu s filmem byly stanoveny s použitím nespecifického substrátu-fluorscein-diacetátu. Účinek derivátů PHMG na dehydrogenázovou aktivitu byl stanoven za použití testu, při kterém byl trifenyltetrazoliumchlorid (TTC) redulovám na trifenylformazan (TF). PCL obsahující granulovaný polyethylenový vosk PHMG a sůl kyseliny sulfanilové (0,6 až 1% hmotnostní) silně inhibují tvorbu biofilmu. Bylo zjištěno, že deriváty PHMG zavedené do PCL mírně ovlivňují aktivitu hydroláz v E. coli a S. aureus v koncentraci 0,2 a 0,6%. Bylo také zjištěno, že dehydrogenázová aktivita byla inhibována PCL filmy obsahujícími deriváty PHMG. PCL obsahující 1% PHMG sulfanilátu nejsilněji inhibují hydrolázovou aktivitu, zatímco PCL modifikovaný 1% granulovaného polyethylenového vosku PHMG vykazuje nejvyšší inhibiční účinek na aktivitu obou enzymů. Kompozity W-PCL a A-PCL (při koncentraci 0,6%) mají optimální kombinaci antibiofilmové aktivity a biologické rozložitelnosti