The influence of diesel fuel on morpho-functional state of Ulvaria obscura (Chlorophyta)

Abstract

There was researched the influence of diesel fuel (DF) on morpho-functional state of Ulvaria obscura (Chlorophyta) of the Barents sea. The reaction of algae on oil products depends on concentration and duration of toxicity. Under the concentration up to 5 mg/l (100 MAC - maximum allowable concentration) there were no visible changes in cell structure during 10 days of experiment; by its end the photosynthesis of algae decreased, probably due to growth of bacterial film on the surface of thalli, preventing photosynthetic apparatus from the light. On the 7th day the number of heterotrophic bacteria increased twice, staying on this level till the end of experiment, the number of hydrocarbon oxidizing bacteria also increased. Under 1000 MAC the chloroplasts lost green colouring, the intensity of photosynthesis significally decreased, but plants maintained vitality. On the 3rd day under 2000-3000 MAC the vacuolization of cells, the destruction of cell structures occured, parallel with the cessation of photosynthesis and the death of macrophytes. The activity of antioxidant system (AAS) in experiments with DF was high, appeared by increasing of formation of hydrogen peroxide and intensity of superoxide dismutase and catalase ferments synthesis. U. obscura adaptates to concentrations of DF up to 2000 MAC.

Physiological changes and rate of resistance of Acrosiphonia arcta (Dillwyn) Gain upon exposure to diesel fuel

“…When the toxicant ingress into the environment takes place, ROS begin to form in the cells and trigger the activation of SOD that converts them into less toxic hydrogen peroxide. Similar changes in SOD activity were observed for Chlorella vulgaris (Calder on-Delgado et al, 2019), Phaeodactylum tricornutum (Wang et al, 2008) and Ulvaria obscura (Salakhov et al, 2020). SOD suppression at a diesel fuel concentration of 5 mg/l (which corresponds to our 100 MPC) was shown by other authors in experiments on Chlorella sp.…”