The fatty acid profile in cod (Gadus morhuaL.) eggs and larvae. Developmental variations and responses to oil pollution

Changes in fatty acid in Tecoma stans grown in mine residues after compost amendment

Amendment tailing heaps with compost may deplete metal(loid)s concentration and improve the conditions for plant development. This research aimed to compare the Tecoma stans ability to grow on soil from the Sonora desert and mining waste (MW) after amendment with compost. Amendment the MW, with compost, decreased soluble As, Cd, Cu, Mn, Pb, and Zn up to 47, 33, 11, 34, 69, and 34%, respectively; increased ten times the leaves weight, and thirteen times the leaf area of the plants. Arsenic, Cd, Pb, Cu, and Zn in plants tissues decreased 27, 28, 27, 12, and 11%, respectively. The bioaccumulation and translocation factors were lower than one, so T. stans do not accumulate these elements. Polyunsaturated fatty acids 18:2ω6 and 18:3ω3 were increased, suggesting lower alteration of thylakoidal membrane integrity due to compost treatment. But, the amendment to the tailing was not enough to deplete the abiotic stress.

Hemolytic activity and fatty acids composition in the ichthyotoxic dinoflagellate Cochlodinium polykrikoides isolated from Bahía de La Paz, Gulf of California

The hemolytic activity of the dinoflagellate Cochlodinium polykrikoides from Bahía de La Paz, Gulf of California was investigated as part of the ichthyotoxic mechanism of this microalga. Two different kinds of erythrocytes, fish and human, were tested for the hemolytic assay. Since fatty acids have been associated with hemolytic activity in C. polykrikoides, the composition of fatty acids of this dinoflagellate was also analyzed. The concentration of C. polykrikoides causing 50% hemolysis (HE(50)) was 4.88 and 5.27x10(6) cellsL(-1), for fish and human erythrocytes, respectively. According to the standard curve of saponin, an equivalence between the hemolytic activity of saponin and the dinoflagellate concentration was found with 1mug saponinmL(-1) equivalent to 1x10(6) cellsL(-1) of C. polykrikoides. The polyunsaturated fatty acids: hexadecaenoic (16:0), docosahexaenoic (22:6 n3) and octadecapentaenoic (18:5 n3) were found in an abundance of approximately 62% of total fatty acids.

Effects of antibacterial agents on transformation of fatty acids in sediment from a marine fish farm site

The conversion of fatty acids in marine fish farm sediment from a simulated abandoned site was investigated. Five containers of aquaculture sediment were followed in 1 year. Antibacterial agents: oxytetracycline, flumequine and oxolinic acid, respectively, were added to three of the containers, while two were controls. The fatty acid composition in the sediment was examined by direct methanolysis on sediment, high-resolution gas chromatography and multivariate data-analysis. The total amount of fatty acids decreased strongly in all containers and the fatty acid profile in the sediment changed clearly towards the profile of natural, unaffected sediment with time. During the experimental period, the added drugs had a retarding effect on the transformation of fatty acids in the sediment. This effect, however, was not detectable after 10 months.