Zbiorniki wodne coraz częściej stają się integralną infrastrukturą dużych miast, pełniąc ważne funkcje estetyczne i rekreacyjne. Nie są one jednak objęte systematycznym monitoringiem mikrobiologicznym. Celem niniejszej pracy była ocena stanu sanitarno-bakteriologicznego zbiornika wodnego „Balaton” położonego w centrum Bydgoszczy. Analizy sanitarne obejmujące liczebność wybranych grup mikroorganizmów wykonane zostały zgodnie ze standardami Polskich Norm. Dodatkowo badania poszerzono o oznaczenie ogólnej liczby bakterii (OLB) oraz ocenę aktywności błony cytoplazmatycznej komórek bakterioplanktonu, wykorzystując w tym celu zestaw barwników fluorescencyjnych LIVE/DEAD® BacLightTM Bacterial Viability Kit. Wykonane badania wykazały, że zasadniczy wpływ na ilość drobnoustrojów miała pora roku. Największą liczbę bakterii psychrofilnych, mezofilnych oraz enterokoków kałowych odnotowano latem, a najmniejszą jesienią. Wyjątek stanowiły bakterie z grupy coli oraz Escherichia coli, których najmniejszą liczbę odnotowano w sezonie wiosennym. Podobne zależności stwierdzono na podstawie analizy ogólnej liczby komórek bakterii, wśród których aktywność błony cytoplazmatycznej wynosiła od 91,5% latem do 72,3% wiosną. Analiza taksonomicznego zróżnicowania dominujących szczepów bakterii wykonana metodą BIOLOG® wykazała, że wszystkie badane izolaty należały do klasy Gammaproteobacteria.
EN
Water reservoirs have become increasingly an integral part of infrastructure of big cities. They play an important aesthetic and recreational functions, but aren’t covered by systematic microbiological monitoring. The aim of this study was evaluation of sanitary and bacteriological condition of the “Balaton” water reservoir located in Bydgoszcz. Sanitary analysis includes the number of selected groups of microorganisms were made in accordance with the Polish Standards recommendations. The study was expanded to determine the total number of bacteria (TNB) and assessment the activity of cytoplasmic membrane of bacterioplankton. In this case was used fluorescent dyes LIVE/DEAD® BacLightTM Bacterial Viability Kit. The studies showed, that the season has a major impact on the distribution of bacterial populations. The highest average number of psychrophilic and mesophilic bacteria and also fecal enterococci was recorded in summer. The exceptions were coliform bacteria and Escherichia coli, which the smallest average number was noted in spring. Similar relationship observed based on the total number bacteria, among which cytoplasmic membrane activity varied from 91.5% in summer to 72.3% in autumn. The taxonomic analysis of dominant bacterial strains prepared using BIOLOG® method showed, that all examinated isolates belonged to Gammaproteobacteria class.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Antibiotic resistance of bacteria was observed in various aquatic environments including seas, rivers, lakes, coastal areas, surface water and sediments. The increased implementation of antibiotics into these environments through medical therapy, agriculture and animal husbandry has resulted in new selective pressures on natural bacterial aquatic populations. Antibiotic resistance of heterotrophic bacteria isolated from the surface microlayer and subsurface water of freshwater coastal polymictic and low-productive lake was studied. Antibiotic resistance was determined by the single disc diffusion method. The resistance level of bacteria to various antibiotics differed considerably. Bacteria were most resistant to ampicillin, ciprofloxacin, clindamycin, erythromycin and penicillin. Majority of bacterial strains showed resistance to 4.6 out of 18 antibiotics tested. As a rule, neustonic bacteria (antibiotic resistance index, ARI 0.44) were more resistant to the studied antibiotics than planktonic bacteria (ARI 0.32). 70-90% of neustonic bacteria were resistant to ampicillin, clindamycin and erythromycin, 60-70% of planktonic bacteria were resistant to ampicillin, ciprofloxacin and penicillin. Differences between pigmented and non-pigmented bacteria in their resistance to the tested antibiotics were observed. Above 40% of achromogenic bacterial strains were resistant to ampicillin, clindamycin and penicillin. Among bacterial strains characterised by their ability to synthesize carotenoids, more than 30% was resistant to ampicillin and ciprofloxacin. Bacterial resistance level to antibiotics depended on their chemical structure. Bacteria isolated from study lake were most resistant to quinolones and lincosamides while they were most susceptible to tetracyclines and aminoglycosides. Results presented in this paper indicate that antibiotics are a significant selection factor and probably play an important role in regulating the composition of bacterial communities in aquatic ecosystems. Adaptive responses of bacterial communities to several antibiotics observed in the present study may have possible implications for the public health.
3
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
This study investigated relationships of hydrological variability and potential food resources for metazooplankton groups: rotifers, cladocerans, copepods and nauplii. Samples were collected monthly during ice-free season from March until November in 2006. Two sampling stations were chosen, the one located in Lake Sakadaš, as a segment of Kopački Rit floodplain (Croatia), and the other in the River Danube. Due to hydrological conditions we divided our samples into two hydrological groups which corresponded to: 1/ increased water level i.e. disturbed phase and 2/ decreased water level representing a more stable phase. Abundance of metazooplankton was not significantly different between hydrological groups in the River Danube. However, it was significantly different between hydrological groups in Lake Sakadaš (one-way ANOSIM R = 0.688, P = 0.024), where during a decreased water level higher abundance of metazooplankton was recorded. Rotifers were the most abundant metazooplankton group during the whole investigated period at both stations and between both hydrological groups comprising almost 99% of total metazooplankton abundance. Rotifers were significantly positively correlated with the total number of bacteria, as well as with ammonium and total phosphorous concentrations. The metazooplankton community in Lake Sakadas was negatively influenced by flooding, but not in the River Danube. Compared to the River Danube the investigated floodplain lake showed potential as a storage zone for metazooplankton development during more stable hydrological periods. During that time abundance of rotifers was related to the heterotrophic component of microbial food web. Hence, this investigation adds to the understanding of the metazooplankton dynamics in river-floodplain systems as well as of their relations with trophic levels under variable hydrological conditions.
4
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Floodplains are lateral river extensions in which lotic, semi-lotic and lentic habitats are formed resulting in high habitat heterogeniety. Consequently biota development is highely influenced by its location within the floodplain and by the hydrological cycle. In the present paper the development of planktonic and biofilm bacteria associated with artificial substrates were investigated in the floodplain lake of the Danube River (Lake Sakadas, Croatia) during different hydrological situations. The aim of the study was to investigate if there was any difference in the bacterial development between two compartments - plankton and biofilm, and how the floods influence these communities. The samples were taken monthly (July.November 2007) from surface and bottom water layer (plankton) and exposed glass slides (biofilm) at two sampling stations. For these purposes bacterial abundance was estimated by the determination of number of colony forming units (CFUs). The development of bacterioplankton was equal between the sites and had its maximum at the time of falling water after the flood pulse. Bacterioplankton abundance correlated significantly with water properties, and it had predictable dynamics comparable with the previous results established in the same floodplain area (Kopacki Rit). The development of biofilm bacteria differed between the sites, and had its maximum prior to the flood pulse, or during the flood. The abundance of attached bacteria correlated with biofilm biomass while it was not significantly correlated with the water properties. Such results describe different development of planktonic and biofilm bacteria. Biofilm bacteria are more independent, compared to bacterioplankton, from the floodplain hydrology.
5
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The investigation was conducted in the Kopacki Rit Nature Park (eastern Croatia) which is established to protect the floodplain area of the Danube River. The samples were collected monthly in four sites (channels and lakes) with increasing distance from the river. The aim of investigation was to examine trophic structure of culturable bacterioplankton in relation to inundation-isolation cycles on sampling sites with unequal degree of connection with the Danube river. A change in the ratio of copiotrophs (r-strategists) to oligotrophs (K-strategists) was expected as the different organic carbon sources emerged. The composition of variables was revealed by Principal Component Analysis of abiotic water properties (temperature, water depth, transparency, pH, electrical conductivity, dissolved oxygen, nutrient concentrations) and the chlorophyll-a concentration. Scores of significant components were used in a Multiple Regression as independent variables and the relationship between the scores and abundance of colony forming units (CFUs) was examined. Regression model was significant only for copiotrophs, and their relative dominance was noticed in couple of samples on more isolated sampling sites. In all other samples oligotrophs were a dominant group, especially during the flood pulses or drainage after it. Their elevated abundance was equally distributed in all groups revealed by Principal Component Analysis, and corresponds to the fluvial action. Also concerning the [eta] squared and R squared values from the two-way ANOVA (sites/samplings) oligotrophs are highly influenced by the sampling period i.e. inundation-isolation cycles. They are probably driven by the allochthonous organic matter provided by floods or have allochthonous origin itself. At the same time, copiotrophs are to some extent coupled with the established water properties, i. e. bottom-up controlled and their abundance is influenced by the localisation of sampling sites in the floodplain. These results describe the development of the conditions that promote habitat specific succession of the culturable bacterioplankton. Established differences had disappeared after additional inundation-isolation cycles.
6
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Results of chemical and bacteriological examinations conducted for surface and subsurface water layers of coastal freshwater lake Dolgie Wielkie were presented. The obtained data indicated that there were substantial differences in concentrations of heavy metals, abundance and productivity of bacteria in the water layers studied. It was found that the highest concentration of heavy metals and the lowest counts of total and heterotrophic bacteria were recorded in the film layer. However, a higher level of secondary production than in neustonic bacteria was found for planktonic bacteria. The results justify a conclusion that heavy metals accumulated in the surface layers may have a significant inhibitory effect on counts and productivity of neustonic bacteria.
PL
Przedstawiono wyniki chemicznych i bakteriologicznych badań powierzchniowych i podpowierzchniowych warstw wody przymorskiego słodkowodnego jeziora Dołgie Wielkie. Uzyskane wyniki wykazały istotne różnice w stężeniu metali ciężkich, liczebności oraz poziomie produkcji bakterii w badanych warstwach wody. Wykazano, że największe stężenie metali ciężkich, najmniejsza ogólna liczebność bakterii oraz liczebność bakterii heterotroficznych notowane było w filmie powierzchniowym. Jednakże wyższy poziom wtórnej produkcji obserwowano u bakterii planktonowych niż neustonowych. Uzyskane wyniki upoważniają do stwierdzenia, że metale ciężkie zakumulowane w powierzchniowych warstwach wody mogą mieć istotny inhibitorowy wpływ na liczebność i produktywność bakterii neustonowych.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.