Neustonic versus epiphytic bacteria of eutrophic lake and their biodegradation ability on deltamethrin

This study evaluated biodegradation of the insecticide deltamethrin (1 μg l−1) by pure cultures of neustonic (n = 25) and epiphytic (n = 25) bacteria and by mixed cultures (n = 1), which consisted of a mixture of 25 bacterial strains isolated from the surface microlayer (SM ≈ 250 μm) and epidermis of the Common Reed (Phragmites australis, (Cav.) Trin. ex Steud.) growing in the littoral zone of eutrophic lake Chełmżyńskie. Results indicate that neustonic and epiphytic bacteria are characterized by a similar average capacity to degrade deltamethrin. After a 15-day incubation, bacteria isolated from the surface microlayer reduced the initial concentration of deltamethrin by 60%, while the average effectiveness of the bacteria found on the Common Reed equaled 47%

On some problems related to the occurrence of Pseudobenedenia nototheniae Lohnston,1931 (Monogenea, Capsalidae, Trochopodinae) off the South Shetlands

Parasites of six Notothenia species were studied in 1979 at he Polish Academy of Sciences′ H. Arctowski Station on the South Shetlands. Only two fish species, namely, Notothenia coriiceps neglecta and N. rossi marmorata, showed the presence of external parasites, Pseudobenedenia nototheniae Johnston, 1931. A number of observations have been made on the parasite′s morphology. Evidence in support of Gibson (1976) who regards P. lauriei Szidat, 1965 as synonymous with P. nototheniae Johnston, 1931 is given

The in ovo study of cadmium embryotoxicity and the search for protectors

Kadm, toksyna środowiskowa o wysokiej zdolności do bioakumulacji i szerokim spektrum działania, stanowi realne zagrożenie dla zdrowia ludzi i zwierząt. Zastosowanie modelu in ovo w badaniach nad toksycznością kadmu pozwala na ocenę skutków narażenia rozwijających się zarodków kurzych na kadm, a ponadto stwarza idealny scenariusz do poszukiwania jego skutecznych protektorów. Zaletą modelu jest wyeliminowanie wpływów środowiskowych i żywienia, a przede wszystkim dostępność i niskie koszty eksperymentu. Przeprowadzone badania pozwoliły ocenić skutki rosnącej ekspozycji na kadm, wprowadzony do białka jaja w 4. dobie inkubacji (w dawce 0-24 μg Cd/jajo), dla rozwoju zarodków kurzych. Oceniano śmiertelność, wady rozwojowe, a także zmiany biochemiczne w narządach piskląt. Analiza aktywności lizosomalnej N-acetyloglukozaminidazy wykazała, że ekspozycja na kadm prowadzi do uszkodzenia nerek i wątroby piskląt. Stwierdzono, że równoczesne podanie kadmu z antagonistycznym cynkiem lub chelatującym tiolem (w wielokrotnie wyższym stosunku molowym) ogranicza jego embriotoksyczność dla ptaków.Cadmium (Cd), an environmental toxin with a high bioaccumulation potential and broad spectrum of activity, poses a real threat to human and animal health. The application of in ovo model to cadmium toxicity studies allows to assess the effects of cadmium exposure for developing embryos and creates an ideal scenario for searching effective protectors. The advantage of the model is elimination of environmental influences, nutrition but most of all the availability and low costs of experiment. The study allowed to assess the effects of increasing exposure to cadmium (at a dose of 0-24 μg Cd/egg, injected to egg albumen on 4th day of incubation) for the development of chicken embryos. The mortality and malformations induced by treatment as well as biochemical changes in chicks blood plasma were determined. Based on lysosomal N-acetylglucosaminidase activity it was found that in ovo exposure to cadmium lead to damage of chicks liver and kidney. Moreover, it has been shown that co-administration of antagonistic metals or chelating thiols (in a multiplied molar ratio) effectively reduced the embryotoxicity of cadmium in birds