Changes in the Quantitative and Functional Characteristics of Bacterioplankton under the Influence of Aqueous Unmodified Fullerene С60 Dispersions.

The effect of aqueous unmodified fullerene C60 dispersions (AFD) at a concentration of 5 mg/L on the total number and metabolic activity of heterotrophic river bacteroplankton was investigated. The stimulating effect of AFD on the number of bacterioplankton and on the activity of electron transport chains in its cells is shown. It is established that, in the presence of AFD, the bactericidal activity of antibiotics decreases. The stimulating effect of fullerene on the natural heterotrophic bacterioplankton, which we discovered, casts doubt on the expediency of using AFD as a bacteriostatic agent.

[Monitoring of the Moskva River Water Using Microbiological Parameters and Chlorophyll a Fluorescence].

The results of investigations of three Moskva River sites with different degree of pollution using a complex of microbiological characteristics and the parameters of chlorophyll a fluorescence are presented. We determined that the bacterioplankton seasonal dynamics at less polluted waters (Tushino and Vorobyovy Gory) were similar and differed significantly from one in more polluted waters (Dzerzhinskii). The number of bacteria with active electron transport chain, as well as their share in the bacterioplankton structure, was higher in the water of Dzerzhinskii (average annual values of 0.23 x 10(6) cells/mL and 14%), that in the less polluted water of Tushino and Vorobyovy Gory (0.14 x 10(6) cells/mL; 6% and 0.15 x 10(6) cells/mL; 7%, respectively). From April to October, the content of chlorophyll a and its photosynthetic activity were the highest in Tushino. In Dzerzhinskii, during spring the increase in photosynthetic activity commenced earlier and was more intensive that the increase in chlorophyll a content, i.e., the increase in phytoplankton biomass was temporarily suppressed. We suggest association of this phenomenon with suppression of organic matter synthesis by phytoplankton due to the high water pollution in Dzerzhinskii. The second autumn peak of chlorophyll a content, that was typical of clear water and was observed in Tushino, did not occur in Dzerzhinskii. We recommend combined application of these microbiological parameters and characteristics of chlorophyll a fluorescence for a monitoring.

[Hydrocarbon-oxidizing microflora from the water of the Baltic sea and Kurshsky bay polluted after a fuel oil spill]. / Uglevodorodokisliaiushchaia mikroflora akvatorii Baltiiskogo moria i Kurshskogo zaliva, zagriaznennykh pri razlive mazuta.

Microbiological studies were conducted in the water of the Baltic sea and the Kurshsky bay polluted with mazut as the result of a tanker wreck in November 1981 as well as in the water of nonpolluted regions. Within the summer of 1982 and 1983, 755 bacterial strains were isolated from water samples taken at three different depths. Bacteria belonging to the genera Pseudomonas, Rhodococcus + Mycobacterium and Arthrobacter predominated in the hydrocarbon-oxidizing cenoses of the Baltic sea and the Kurshsky bay. The central part of the Baltic sea pure from mazut did not differ from the polluted regions in the qualitative composition of the hydrocarbon-oxidizing bacterial flora. Rhodococci and mycobacteria prevailed in the water near harbours, and pseudomonades, in the open waters. The greatest variety of species was found at a depth of 1 m. The proportion between the predominating genera of hydrocarbon-oxidizing bacteria was not stable. The state of studies conducted with the hydrocarbon-oxidizing microflora is analysed and the factors causing discrepancies are discussed. One must keep in mind that it is necessary to use a strictly elective medium and to examine cultures with a microscope many times throughout their growth in the isolation and identification of hydrocarbon-oxidizing bacteria. The interrelationship is analysed between the predominant genera of hydrocarbon-oxidizing bacteria.

[Effect of cyanobacteria excretions and cell biomass on hydrocarbon-oxidizing mycobacteria]. / Vliianie vydelenii i kletochnoi biomassy tsianobakterii na uglevodorodokisliaiushchie mikobakterii.

The presence of cyanobacterial cells and their exocellular excretions in an aqueous ecosystem stimulated biodegradation of diesel fuel. As was established using the technique of complete factor analysis, nitrogen addition to the medium and the presence of cyanobacterial cells in it are important for the growth of oil-oxidizing bacteria, while exocellular excretions of the cells are not sufficient for such a growth. The mycobacterial growth depended, to a certain extent, on the age of cyanobacterial cultures.

[Microbiologic oxidation of diesel fuel by the total factor experiment method]. / Izuchenie mikrobiologicheskogo okisleniia dizel'nogo topliva metodom polnogo faktornogo éksperimenta.

The effect of nitrogen, phosphorus, glucose and temperature on the assimilation of diesel fuel and the biomass yield of Mycobacterium mucosum was studied by the method of complete factor experiment. The concentration of nitrogen and phosphorus were shown to be most important for the above processes. The growth dynamics of the culture was studied as well as the utilization by it of diesel fuel and glucose added to the medium separately or in combination. The presence of glucose in the medium had no effect on the utilization of diesel fuel; however, the utilization of glucose in the presence of diesel fuel was considerably decelerated.