No abstract

Taxonomic compositions of epiphytic bacterial communities in water areas differing in levels of oil pollution were revealed. In total, 82 bacterial genera belonging to 16 classes and 11 phyla were detected. All detected representatives of epiphytic bacterial communities belonged to the phyla Actinobacteria, Bacteroidetes, Planctomycetes, Proteobacteria, Verrucomicrobia, Acidobacteria, Cyanobacteria, Firmicutes, and Fusobacteria and candidate division TM7. The ratio of the phyla in the communities varied depending on the levels of oil pollution. New data on taxonomic composition of uncultivated epiphytic bacterial communities of Fucus vesiculosus were obtained.

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.

There was shown the role of live and dry algae Fucus vesiculosus (Phaeophyceae) in the purification of the coastal waters from petroleum products. It was revealed that live algae can be effectively used for preventive, daily purification of marine water, when the content of diesel fuel does not exceed 3 mg/l. For the first time, the prospect of using dry fucus for bioremediation of marine water in emergencies creating a concentration of petroleum products in water of 1 g/l has been determined. In the case of using living plants to neutralize toxicant, the decisive role in the process belongs to the symbiotic association of algae and hydrocarbon-oxidizing bacteria. In case of using dry algae, dried macrophytes become a reservoir for the accumulation of diesel fuel. The main work on the destruction of hydrocarbons, probably, lies on HOB, as well as on physicochemical processes. Metabolic processes inherent in living algae and leading to the destruction of petroleum hydrocarbons weren’t determined in this case.

The results of algological researches of the Murmansk Marine Biological Institute for the period from 2015 till 2019 are presented with the following achievements. Analysis of the expeditionary samples revealed 79 species of algae macrophyte, rarely found at the Murman coast, among them 10 species were Chlorophyta, 33 –Phaeophyceae, 36 –Rhodophyta. A significant increase of the occurrence (presence) of Ulva lactuca L.at the Murmansk coast of the Barents Sea in 2009–2019 was noted, due to positive climatic anomalies caused by an increase of the influx of the Atlantic waters. It has been shown for the first time that the various morphological forms of the brown alga Fucus distichuslived on the littoral of the Murmansk coast of the Barents Sea are genetically homogeneous. The morphology of embryogenesis, early ontogenesis of F. distichusis described. It was determined that hydrostatic pressure (from 4 atm) negatively affects the development of spores of Alaria esculentaand Palmaria palmata, and can determine the lower boundary of algae growth. It was shown that a change in the activity of enzymes of the antioxidant system P. palmata: (catalase and superoxide dismutase) depending on the temperature of the environment) is one of the mechanisms of adaptation of algae to growth in the tidal zone and seasonal temperature fluctuations. There were revealed the negative effect of the red algae P. palmataon the growth of F. distichus, F. serratusand the positive effect of Fucus on the growth of P. palmata. A change in the seasonal concentration of 4 B vitamins was determined (riboflavin, pantothenic acid, nicotinic acid and pyridoxine) of P. palmata. Isolated vitamins take part in spore formation and can act as antioxidants. An electron microscopic analysis of the “young” multicellular sporophytes of Saccharina latissimarevealed the presence in cells of a developed photosynthetic reticulum, and a high partial mass of mitochondria, energy structures that apparently provide an intensive process of cell division at this stage of ontogenesis. The participation of florotannins in the regeneration of thallus of Fucus algae was demonstrated. The data on the quantitative and qualitative composition of cultivated and uncultivated epiphytic bacteria of Fucus algae from clean and oil polluted areas of coastal waters of the Barents Sea have been obtained.For the first time, the evidence base presents that morphologically and systematically various macrophyte algae, differing in structure and systematic affiliation, possess in their ability to form a symbiotic association with hydrocarbon-oxidizing bacteria, they show a pronounced ability to sorb and to destruct the oil products, which determines their significant role in bioremediation of coastal waters.