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The influence of soluble microbial products on microbial community composition: hypothesis of microbial community succession

100%

Chipasa K. B. , Medrzycka K.

Polish Journal of Microbiology

2008

tom 57

nr 1

Soluble microbial products (SMP) are organic compounds produced by activated sludge microorganisms as they degrade substrates. They include by-products of microbial activity, death and lysis. The available literature does not reveal how SMP influence microbial community composition. In this regard, we microscopically studied changes in composition of microbial communities, especially protozoa and metazoa, under the influence of increased as well as reduced levels of SMP. The presence of SMP at high level significantly caused changes in microbial community composition. Microbial species shifted from attached ciliates (12-175 μm) to free-swimming and crawling ciliates (35-330 μm) and then invertebrates, which included rotifers (0.2-1 mm) and nematodes (1-50 mm). The shift of small-size microorganisms to large ones was observed as one of the most significant influences of SMP. Attached ciliates reappeared when we removed the SMP that had accumulated in the bioreactors - we have called this as the resurrection phenomenon of microorganisms. Such rapid changes in microbial community composition were not observed in the experiment with low concentration of SMP. Overall, the results suggest that accumulation of SMP is one of the intrinsic regulatory mechanisms that control viability and dormancy of microbial communities in activated sludge.

Detergenty w przyrodzie

100%

Medrzycka K.

Ekoprofit

1997

nr 06

40-44

Wplyw sezonowych zmian temperatury na wlasciwosci sedymentacyjne osadu czynnego

80%

Cytawa S. , Medrzycka K. , Tomczak-Wandzel R.

Ekologia i Technika

2007

tom 15

nr 2

39-43

Badania zanieczyszczenia osadow portowych zwiazkami cynoorganicznymi

80%

Medrzycka K. , Dubiella-Jackowska A. , Wasik A. , Namiesnik J.

Przegląd Komunalny

2006

nr 09

75-77

The effect of anionic surfactant concentration on activated sludge condition and phosphate release in biological treatment plant

80%

Dereszewska A. , Cytawa S. , Tomczak-Wandzel R. , Medrzycka K.

Polish Journal of Environmental Studies

2015

tom 24

nr 1

This paper discusses the influence of a wide range of anionic surfactant concentrations on activated sludge. Linear alkylbenzene sulphonate (LAS) was chosen as an example of a commonly used anionic surfactant. The fate of the surfactant during biological treatment of wastewater was tested. The effect of surfactant on glucose and starch removal was studied. It has been found that in the case of glucose the removal was independent of LAS concentration, while in the case of starch it was incomplete at high surfactant loads (above 15 mg·(g·dss)⁻¹). The study established that surfactants can activate or inhibit microorganism activity, depending on surfactant concentration. LAS loads up to 3 mg·(g·dss)⁻¹ positively stimulate the removal of COD, phosphorus release and the respirometric activity of the sludge. LAS loads higher than 15 mg·(g·dss)⁻¹ inhibit respiration of activated sludge bacteria and decrease phosphorus removal. It also affects the morphology of activated sludge flocs, causing their fragmentation and lysis of protozoa cells.

Podczyszczanie sciekow z zakladow miesnych metoda filtracji przez zloza torfowo-kredowe

80%

Tomczak-Wandzel R. , Medrzycka K. , Matyskiewicz E.

Gospodarka Mięsna

2004

tom 56

nr 06

24-26

Tendencies of change in the chemistry of precipitation at three monitoring stations 1996-1999

61%

Walna B. , Polkowska Z. , Malek S. , Medrzycka K. , Namiesnik J. , Siepak J.

Polish Journal of Environmental Studies

2003

tom 12

nr 4

This study compares the results of three stations differing greatly in geography, and tendencies of change in the chemistry of precipitation (open and throughfall) in the years 1996-1999. The mean annual pH is lower than 5.2, and often drops below 4.6. A distinct decline in the concentrations of sulphate ions at all the stations is observed.