Wyniki wyszukiwania - Biblioteka Nauki

1

Phylogenetic diversity and abundance of bacteria from surface microlayer and subsurface water in eutrophic lake

100%

Walczak M. , Swiontek Brzezinska M.

Polish Journal of Ecology

|

2010

|

tom Vol. 58, nr 1

177-186

EN

The bacteria from different phylogenetic groups were studied in surface microlayer (SM, up to 100 [mu]m ) versus subsurface water (SW - 20 cm) in eutrophic lake from spring to autumn of 2007. Abundance of bacteria was determined using a combination of direct counting of 4', 6-diamidino-2-phenylindole and the phylogenetic diversity was determined in fluorescence in situ hybridization (FISH) method with group-specific, fluorescently labeled oligonucleotide probes. The numbers of DAPI bacteria varied between 4.75 and fluorescence in situ hybridization (FISH) demonstrated that Eubacteria constituted the majority of the whole bacterial population and their percentage share ranged from 59 to 75%. Abundances of alpha- beta-Proteobacteria and Cytophaga-Flavobacteria groups varied across seasons, layers, and lacustrine zones. The lowest number of alpha-Proteobacteria group bacteria was observed in spring (SM - 0.2 x 10[^6], SW - 0.16 x 10[^6] cells cm[^-3]), whereas the highest in autumn (SM - 0.62 x 10[^6], SW - 1.6 x 10[^6] cells cm[^-3]). The percentage share of these groups of bacteria in the Eubacteria domain was lower in spring (20.50%) than in summer and autumn (from 65 to over 80%). No fixed difference between the composition of SM and SW bacteria was noticed. Seasonally occurred changes are similar in both layers.

2

Rola oczyszczalni hydrobotanicznych w oczyszczaniu ścieków z terenów wiejskich

80%

Lalke-Porczyk E. , Swiontek Brzezinska M. , Donderski W.

|

2010

|

tom T. 10, z. 3

119-127

PL

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.

EN

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.

3

Microbiological contamination of water in fountains located in the city of Torun, Poland

80%

Burkowska-But A. , Swiontek Brzezinska M. , Walczak M.

|

tom 20

|

nr 4

4

Microbial degradation of shrimp waste in soil

80%

Swiontek Brzezinska M. , Lalke-Porczyk E. , walczak M. , Donderski W.

|

nr 3

627-633

5

Degradation of chitin in natural environment : role of Actinomycetes

80%

Swiontek Brzezinska M. , Lalke-Porczyk E. , Donderski W. , Walczak M.

|

tom Vol. 57, nr 2

229-238

EN

The actinomycetes in water samples and bottom sediments of lowland, eutrophic lake as well as in soil (farmland, sandy) of the lake basin were studied. Chitin-degrading actinomycetes were isolated (with a plate technique) from each habitat; subsequently, their chitinolytic activity (with the fluorometric method) was determined in relation to temperature (10-50[degree]C) and the physical type of chitinous substance (colloidal chitin, chitin powder, and shrimp shells). This study demonstrated that actinomycetes were the most abundant in soil samples (average of 18x10[^3] CFU g[^-1] in farmland soil, 9x10[^3] CFU g[^-1] in sandy soil), and the least abundant in water samples (average of 2.7x10[^1] CFU mL[^-1] in lake water at neutral pH, 0.6x10[^1] CFU mL[^-1] in lake water with alkaline pH). The highest percentage of chitinolytic actinomycetes was observed in soil (average of 80% in sandy soil and 85% in farmland soil). Chitinolytic actinomycetes also made up a large fraction of total actinomycetes in water samples (average of 73%). In silt and sandy sediments, percentages of chitinolytic actinomycetes equaled 23 and 15%, respectively. Actinomycetes collected in soil were characterized by the highest activity (average of 14 nmol MUF mg[^-1] of protein h[^-1] in farmland soil, 8.5 nmol MUF mg[^-1] protein h[^-1] in sandy soil). The lowest activity was observed among benthic actinomycetes (average of 5.4 nmol MUF mg[^-1] of protein h[^-1] in silt, 0.65 nmol MUF mg[^-1] protein h[^-1] in sandy sediments). The impact of temperature and the type of chitinous substrate on the activity of chitinases produced by actinomycetes demonstrated that their activity peaked at 40[degree]C and in the presence of colloidal chitin. Observed differences in actinomycetales number and activity in the lake and the soil may be explained by higher accumulation of chitin substances in the soil. This polymer allows microorganisms to continually synthesize chitinolytic enzymes and take active part in that compound decomposition.