Wpływ promieniowania UV na aktywność enzymatyczną i oddechową bakterii neustonowych i planktonowych

The surveys were carried out in the pelagic zone of Brzezno lake (the Tuchola Forest). Water samples were collected from the surface microlayer and the subsurface water. The surveys covered respiratory activity of bacteria, using a measurement system OxiTop Control. Also, general activity of hydrolytic enzymes was estimated measuring rates of fluorescein release from fluorescein diacetate. The research was conducted in two experimental layouts: with and without humic substances. Conducted surveys proved substantially lower respiratory and hydrolytic activity of bacteria influenced by UVB radiation compared with bacteria without UVB radiation. The experiments did not prove unambiguous protective operation of HS – only for selected strains with bacteria subjected to UVB radiation in presence of HS demonstrated lower decrease of respiratory and hydrolytic activity.Badania prowadzono w dwóch układach doświadczalnych: bez substancji humusowych (SH) i w obecności tych substancji. W wyniku przeprowadzonych badań stwierdzono zdecydowanie niższą aktywność oddechow ą i hydrolityczną bakterii po naświetleniu UVB, w porównaniu z bakteriami nie naświetlonymi. Nie stwierdzono jednoznacznie ochronnego działania SH, jedynie w przypadku niektórych szczepów naświetlanie bakterii UVB w obecności SH powodowało mniejszy spadek aktywności oddechowej i hydrolitycznej

Wpływ UVB na aktywność syntezy DNA i białek komórkowych przez bakterie środowiska wodnego

The studies were carried out in 2007 based on water samples collected from SM and SW of pelagic zone of Brzezno lake. For the purpose of further research, representative collection of bacterial strains was isolated from collected samples. The progress of the research included estimation of the DNA and cellular protein synthesis activity of the bacteria subjected to UVB radiation. The survey was conducted in two experimental layouts: with and without humic substances (HS) playing role of compounds potentially protective from UV radiation. Conducted research demonstrated that under influence of UVB radiation the SM and SW bacteria activity of DNA and cellular protein synthesis were strongly inhibited. On the other hand, presence of HS have another impact on DNA and cellular protein synthesis.Badania prowadzono w 2007 r., pobierając próbki wody z MP i WPP w strefie pelagialu jeziora Brzeźno. Z pobranych próbkach wody izolowano reprezentatywną kolekcję szczepów, na których wykonywano dalsze badania. W toku badań oznaczano aktywność syntezy DNA i białek komórkowych bakterii poddanych promieniowaniu UVB. Badania prowadzono w dwóch układach doświadczalnych: bez substancji humusowych (SH) i w obecności tych substancji jako związków o działaniu potencjalnie ochronnych przed UV. Przeprowadzone badania wykazały, że pod wpływem promieniowania UVB aktywność syntezy DNA i białek komórkowych ulegały silnej inhibicji. Natomiast obecność SH inaczej wpływa na syntezę DNA i białek

The origin of sulphates in the deep Pleistocene aquifer near Wysoka based on isotopic and microbiologic research

Celem przeprowadzonych badań była identyfikacja źródła pochodzenia siarczanów w głębokim poziomie wodonośnym w rejonie Wysokiej. W pracy zaprezentowano wyniki badań składu izotopowego siarczanów oraz badań mikrobiologicznych w obszarze badań. Teren badań znajduje się w zachodniej części Pojezierza Krajeńskiego, gdzie głęboki poziom plejstoceński występuje w obrębie doliny kopalnej w rejonie Wysokiej. W obszarze doliny kopalnej wody podziemne głębokiego poziomu plejstoceńskiego zawierają podwyższone zawartości jonów siarczanowych i chlorkowych. Podwyższone stężenie chlorków w głębokim plejstoceńskim poziomie wodonośnym jest związane z ascenzją solanek z poziomów mezozoicznych, natomiast źródłem siarczanów jest utlenianie pirytu przez bakterie z gatunku Thiobacillus denitrificans.The aim of this study was to identify the origin of sulphates in a deep Pleistocene aquifer in the Wysoka area. The isotopic composition of sulphates and microbiological conditions in the aquifer are presented in the paper. The study area is located in the western part of the Krajna Lakeland, where the deep Pleistocene sandy aquifer was found over an area of buried valley in the vicinity of Wysoka. The groundwater of the deep aquifer contains increased concentration of sulphate and chloride ions. The elevated chloride concentrations in the aquifer are related to the ascending brines from Mesozoic formations. However, the origin of sulphates in the deep Pleistocene aquifer is related to oxidation of pyrite by Thiobacillus denitrificans

Microbial air contamination in indoor environment of a university library

The present study was aimed at evaluating the number of bacteria and mould fungi in the indoor and outdoor environment of Toruń University Library. The sampling sites were located in the rooms serving the functions typical of libraries (i.e. in the Main Reading Room, Current Periodicals Reading Room, Collections Conservation Laboratory, Old Prints Storeroom, in rooms serving other (non-library) functions (i.e. main hall, cafeteria, and toilet) as well as outside the library building. The analyses reveal that the concentrations of bacterial as well as fungal aerosols estimated with the use of the impaction method ranged between 101-103 CFU·m-3, which corresponds to the concentrations normally observed in areas of this kind. Evaluation of the hygienic condition of the studied areas was based on the criteria for microbiological cleanliness in interiors submitted by the European Commission in 1993. According to this classification, the air was considered to be heavily or moderately contaminated with bacteria, while the air contamination with mould fungi was described as low or moderate. The air in the Old Prints Storeroom was considered the least contaminated with microbial aerosol

Changes in bacterial and archaeal communities during the concentration of brine at the graduation towers in Ciechocinek spa (Poland)

This study evaluates the changes in bacterial and archaeal community structure during the gradual evaporation of water from the brine (extracted from subsurface Jurassic deposits) in the system of graduation towers located in Ciechocinek spa, Poland. The communities were assessed with 16S rRNA gene sequencing (MiSeq, Illumina) and microscopic methods. The microbial cell density determined by direct cell count was at the order of magnitude of 10(7) cells/mL. It was found that increasing salt concentration was positively correlated with both the cell counts, and species-level diversity of bacterial and archaeal communities. The archaeal community was mostly constituted by members of the phylum Euryarchaeota, class Halobacteria and was dominated by Halorubrum-related sequences. The bacterial community was more diverse, with representatives of the phyla Proteobacteria and Bacteroidetes as the most abundant. The proportion of Proteobacteria decreased with increasing salt concentration, while the proportion of Bacteroidetes increased significantly in the more concentrated samples. Representatives of the genera Idiomarina, Psychroflexus, Roseovarius, and Marinobacter appeared to be tolerant to changes of salinity. During the brine concentration, the relative abundances of Sphingobium and Sphingomonas were significantly decreased and the raised contributions of genera Fabibacter and Fodinibius were observed. The high proportion of novel (not identified at 97% similarity level) bacterial reads (up to 42%) in the 16S rRNA gene sequences indicated that potentially new bacterial taxa inhabit this unique environment