Wyniki wyszukiwania - Biblioteka Nauki

1

Humic substances as source of carbon and nitrogen for heterotrophic bacteria isolated from lakes of different trophy

100%

Donderski W. , Wodkowska A.

Polish Journal of Environmental Studies

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1997

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tom 06

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nr 4

EN

The ability of planktonie and benthie bacteria isolated from the oligo-mesotrophic lake Jasne and the highly eutrophized, alloiotrophic lake Stęgwica, to utilize humic substances was studied. It was found that all the bacteria used in the experiments were able to utilize lake humus. The most intensive development of bacteria was observed in the presence of humic substances which were the only source of nitrogen, it was weaker when the humic substances were the only source of carbon, and it was weakest when they were the only source of both nitrogen and carbon. The ability of planktonie and benthie bacteria isolated from lakes of different trophy to utilize humic substances is similar.

2

Distribution and physiological activity of heterotrophic benthic bacteria in lakes with different trophic conditions located in the Bory Tucholskie National Park (Poland)

80%

Kubera L. , Donderski W.

Polish Journal of Natural Sciences

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2017

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tom 32

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nr 3

EN

Research on ecophysiology of benthic bacteria indicates that microbiological processes which occur in bottom sediments have a major influence on the development of water bodies. Organic matter accumulated on the bottom makes lakes shallower and accelerates their aging. Microbiological processes are particularly important in small lakes, which are a common element of the environment. This article presents the results of the investigation of the distribution of heterotrophic bacteria in the bottom sediments of four lakes with different trophic conditions in the Bory Tucholskie National Park and the relationship between the number of benthic bacteria and their physiological activity. The total number of benthic bacteria and the ability of isolated strains to carry out selected physiological processes were assessed by cultivating bacteria on appropriate substrates. We also determined the coefficient of physiological activity, which was then used for the correlation analysis and verification of the research hypothesis. The highest number of benthic bacteria was found in the eutrophic and dystrophic lakes. The lowest number was recorded in lake sediments of the mesotrophic lake, although at this site the studied strains were the most active. As a result, the correlation analysis confirmed the hypothesis that there is no relationship between the metabolic potential of benthic bacteria and their number in a sample.

PL

W badaniach nad ekofizjologią bakterii bentosowych prowadzonych na przestrzeni lat potwierdzono, że procesy mikrobiologiczne zachodzące w osadach dennych mają fundamentalny wpływ na kierunek kształtowania się zbiorników wodnych. Zdeponowane na ich dnie substancje organiczne przyczyniają się do wypłycania i starzenia się zbiorników jeziornych. Procesy te mają szczególne znaczenie w kontekście niewielkich jezior, które stanowią bardzo liczny i ważny komponent środowiska naturalnego. W artykule zaprezentowano wyniki badań podjętych w celu ilościowej oceny występowania bakterii heterotroficznych w osadach zróżnicowanych troficznie jezior położonych w Parku Narodowym „Bory Tucholskie” oraz wpływu liczebności populacji bakteriobentosu na ich aktywność fizjologiczną. Ogólną liczbę bakterii bentosowych oraz zdolność wyizolowanych szczepów do przeprowadzenia wybranych procesów fizjologicznych oznaczono metodami hodowlanymi na podłożach testowych. Wyznaczono ponadto wskaźnik aktywności fizjologicznej, który umożliwił wykonanie analizy korelacji i weryfikację hipotezy badawczej. Na podstawie analiz największą liczebność bakterii bentosowych stwierdzono w jeziorze eutroficznym oraz dystroficznym. Najmniejszą liczbę bakterii odnotowano w osadach jeziora mezotroficznego, jednakże na stanowisku tym analizowane szczepy najintensywniej przeprowadzały procesy fizjologiczne. W konsekwencji w analizie korelacji potwierdzono hipotezę o braku zależności potencjału metabolicznego szczepów bakterii bentosowych od ich liczebności w badanej próbie.

3

The influence of heavy metals on the activity of chitinases produced by planktonic, benthic and epiphytic bacteria

80%

Donderski W. , Swiontek Brzezinska M.

Polish Journal of Environmental Studies

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2005

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tom 14

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nr 6

EN

Research was carried out on the influence of heavy metals on the activity of chitinases produced by chitinolytic bacteria isolated from Moty Bay in Lake Jeziorak. In tests on the concentration of heavy metal ions in the surface water, the highest concentration of copper and zinc ions was found in July in the littoral zone, of cobalt ions in September in the pelagic zone and of lead ions in August, also in the pelagic zone. Studies on the number of chitinolytic bacteria have shown that the highest number of chitinolytic bacteria among the total number of heterotrophic bacteria occurred on macrophytes and in bottom sediments. The highest percentage of chitinolytic bacteria was found in the surface water, and the lowest in the bottom sediments. As follows from research on the influence of heavy metals on the activity of chitinases , in the majority of the strains tested, heavy metal ions inhibited chitinolytic activity as concentration increased.

4

The utilization of N-acetyloglucosamine and chitin as sources of carbon and nitrogen by planktonic and benthic bacteria in Lake Jeziorak

80%

Donderski W. , Swiontek Brzezinska M.

Polish Journal of Environmental Studies

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2003

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tom 12

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nr 6

EN

It follows from the research conducted on the number of chitinolytic bacteria among planktonic and benthic bacteria that they occur in a higher number in bottom sediments than in water. However, the percentage of chitinolytic bacteria among the total number of heterotrophic bacteria was higher in the water than in the bottom sediments. Chitinolytic bacteria and the bacteria unable to decompose chitin most readily utilized N-acetyloglucosamine as additional sources of carbon and nitrogen. Chitinolytic bacteria developed well on a substrate with colloidal chitin as the only or an additional source of carbon and nitrogen. However, bacteria unable to decompose chitin displayed very weak growth on a substrate with colloidal chitin as the only source of carbon and nitrogen.

5

The proteolytic activity of benthic bacteria in three estuarine lakes

60%

Mudryk Z. , Donderski W.

Oceanologia

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1992

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tom 32