Chlorinated organic compounds in aquatic biological resources of the Baltic region

The results of studying dependencies of levels of polychlorinated biphenyls (PCBs) and chlorinated pesticides in the liver and muscles of the main commercial fish species of the Baltic Sea (sprat, herring, cod, flounder), the Vistula and the Curonian Bay (pike-perch, bream, roach) on the fishing area, season and fish species have been considered. Determination of PCBs and pesticides has been carried out in accordance with MVI MN 2352–2005 "Method for simultaneous determination of residual amounts of PCBs and organochlorine pesticides in fish and fish products by gas-liquid chromatography". Separation, identification and quantification have been performed by the gas chromatography Varian 3400 on the DB-1701 column, 30 m 0.25 mm 0.25 m, the column temperature 150–250 °C, the detector one – 300 °C. Identification and quantification have been performed by retention time of individual PCB congeners by the internal standard. The content of PCBs in liver of the Curonian and Vistula Bays fish is much lower than in liver of aquatic biological resources (ABR) of the Baltic Sea. Hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) are accumulated more intensively in liver of fish caught in the southern part of the Baltic Sea. β-HCH and γ-HCH prevail in the liver and muscle tissue of ABR samples as individual organochlorine pesticides (OCPs). The all three isomers of HCH are present in cod liver. Accumulation ratio in cod liver compared to that in the muscle tissue content reaches 7-8 units HCH for isomers, and for DDT and metabolites – 10-12 units. It has been proposed that the secondary admission of HCH in the aquatic environment and in ABG (delivery from sediments) takes place. Organochlorine pesticides such as hexachlorobenzene, heptachlor and aldrin are present in the Baltic Sea ABR in quantities below the detection limit used in the analysis methods. In spring and summer, there is an increased level of HCH and DDT in the liver of roach

Studies on the Structure and Properties of Membrane Phospholipase A1 Inclusion Bodies Formed at Low Growth Temperatures Using GFP Fusion Strategy

The effect of cultivation temperatures (37, 26, and 18 °C) on the conformational quality of Yersinia pseudotuberculosis phospholipase A1 (PldA) in inclusion bodies (IBs) was studied using green fluorescent protein (GFP) as a folding reporter. GFP was fused to the C-terminus of PldA to form the PldA-GFP chimeric protein. It was found that the maximum level of fluorescence and expression of the chimeric protein is observed in cells grown at 18 °C, while at 37 °C no formation of fluorescently active forms of PldA-GFP occurs. The size, stability in denaturant solutions, and enzymatic and biological activity of PldA-GFP IBs expressed at 18 °C, as well as the secondary structure and arrangement of protein molecules inside the IBs, were studied. Solubilization of the chimeric protein from IBs in urea and SDS is accompanied by its denaturation. The obtained data show the structural heterogeneity of PldA-GFP IBs. It can be assumed that compactly packed, properly folded, proteolytic resistant, and structurally less organized, susceptible to proteolysis polypeptides can coexist in PldA-GFP IBs. The use of GFP as a fusion partner improves the conformational quality of PldA, but negatively affects its enzymatic activity. The PldA-GFP IBs are not toxic to eukaryotic cells and have the property to penetrate neuroblastoma cells. Data presented in the work show that the GFP-marker can be useful not only as target protein folding indicator, but also as a tool for studying the molecular organization of IBs, their morphology, and localization in E. coli, as well as for visualization of IBs interactions with eukaryotic cells

Antimicrobial action of the essential oil of Lippia gracilis Schauer

Antimicrobial activity of the essential oil (EO) of Lippia gracilis Schauer over fungi and heliconia endophytic bacteria was evaluated. For the fungi Geotrichum candidum; Trichoderma viride; Torula herbarum; Paecillomyces sp.; Fusicoccum sp.; P. aeruginens; Curvularia lunata; Aspergillus nidulans; A. flavus; and A. niger mycelial discs were inoculated in PDA medium with oil (0; 420; 440; 460; 480 e 500 µL L-1). The inhibition percentage in 420 µL L-1 was 100% for all fungi, except for C. lunata and A. niger, which was 95.58% and 89.40% , respectively. In other experiment, a suspension of the Salmonella choleraceuis-diarizonae, Enterobacter asburiae, Bacillus thuringiensis, B. pumilus, B. cereus, Klebsiella pneumoniae, and E. hormaechei was individually added to the solid NYDA medium dishes. In each dish, wells were drilled in medium and filled with water or EO (420 µL L-1). The diameter of the inhibition halo was assessed. K. pneumoniae was the bacterial species less sensitive and E. hormaechei was the most sensitive.<br>Avaliou-se a atividade antimicrobiana do óleo essencial (OE) de Lippia gracilis Schauer sobre fungos contaminantes de laboratórios de cultura de tecidos vegetais e bactérias endofíticas de helicônias. Discos de micélio dos fungos Geotrichum candidum; Trichoderma viride; Torula herbarum; Paecillomyces sp.; Aspergillus nidulans; Fusicoccum sp.; A. flavus; P. aeruginens; Curvularia lunata e A. niger, foram inoculados em meio BDA com óleo (0; 420; 440; 460; 480 e 500 µL L-1). O percentual de inibição em 420 µL L-1 foi de 100% para todos os fungos exceto paraC. lunata and A. niger, o qual foi de 95.58% and 89.40% respectivamente. Em outro experimento, suspensão das espécies Salmonela choleraceuis-diarizonae, Enterobacter asburiae, Bacillus thuringiensis, B. pumilus, Klebsiella pneumoniae, E. hormaechei, Bacillus pumilus, B. cereus, B. pumilus foi individualmente adicionada ao meio NYDA, que foi vertido em placas de Petri e, após solidificado, perfurado e preenchido com água ou óleo (420 µL L-1). Avaliou-se o diâmetro do halo de inibição. Avaliou-se também, a inibição em meio líquido. K. pneumoniae foi a espécie bacteriana menos sensível e E. hormaechei foi a mais sensível