Enrichment of Cryoconite Hole Anaerobes: Implications for the Subglacial Microbiome.

Glaciers have recently been recognized as ecosystems comprised of several distinct habitats: a sunlit and oxygenated glacial surface, glacial ice, and a dark, mostly anoxic glacial bed. Surface meltwaters annually flood the subglacial sediments by means of drainage channels. Glacial surfaces host aquatic microhabitats called cryoconite holes, regarded as "hot spots" of microbial abundance and activity, largely contributing to the meltwaters' bacterial diversity.

Biologically-Induced Precipitation of Minerals in a Medium with Zinc Under Sulfate-Reducing Conditions.

Sulfate-reducing microbial communities were enriched from soils collected in areas with crude-oil exploitation. Cultures were grown in modified Postgate C medium and minimal medium, with ethanol or lactate as an electron donor. The batch cultures were grown with addition of zinc in concentrations of 100-700 mg/l.

Sulphate reducing activity detected in soil samples from Antarctica, Ecology Glacier Forefield, King George Island.

We determined sulphate-reducing activities in media inoculated with soils and with kettle lake sediments in order to investigate their potential in geomicrobiological processes in low-temperature, terrestrial maritime Antarctic habitats. Soil and sediment samples were collected in a glacier valley abandoned by Ecology Glacier during the last 30 years: from a new formed kettle lake sediment and forefield soil derived from ground moraine. Inoculated with these samples, liquid Postgate C and minimal media supplemented with various carbon sources as electron donors were incubated for 8 weeks at 4°C.

Application of aerobic microorganisms in bioremediation in situ of soil contaminated by petroleum products.

Aerobic microorganisms able to biodegrade benzene, toluene, ethylbenzene, xylene (BTEX) have been isolated from an area contaminated by petroleum products. The activity of the isolated communities was tested under both laboratory and field conditions. Benzene, toluene, ethylbenzene and xylene were added to the cultures as the sole carbon source, at a concentration of 500 mg/L.

Biotransformation of phosphogypsum in wastewaters from the dairy industry.

The biotransformation of phosphogypsum by stationary cultures of sulphate reducing bacteria (SRB) in dairy wastewaters (sterile and non-sterile) enriched in phosphogypsum, was studied SRB were isolated from soil contaminated with petroleum-derived products and from wastewaters from the petroleum-refining industry, taking into account that these environments are characteristic for the bacteria of the studied group. The biotransformation products formed were investigated using biological and mineralogical methods. Sulphides in the cultures were determined using the iodometric method, sulphates with the hot barium method, COD by the dichromate method.

Biotransformation of phosphogypsum on distillery decoctions (Preliminary results).

The paper presents the activity of anaerobic bacterial communities isolated from soil polluted by aircraft fuel on distillery decoctions with phosphogypsum. The microorganisms were selected using the microcosms method, and then enriched on Postgate medium with ethanol. The isolated communities became the inoculum to establish a culture on potato and rye distillery decoctions.

Geomicrobiological aspects of the oxidation of reduced sulfur compounds by photosynthesizing bacteria.

The activity of photosynthesizing sulfur bacteria in a continuous culture was studied. The bacteria were isolated from the natural environment with the use of the Winogradski column. Isolated bacteria were cultured in synthetic medium and in the effluent from the column containig HS-.

Effectiveness of biodegradation of petroleum products by mixed bacterial populations in liquid medium at different pH values.

The possibility of using mineral oils as a carbon source by bacteria adapted to high oil concentrations was tested in liquid media with different pH values (pH = 5, 7 and 9). Two types of inocula were tested: inoculum I consisted of selected strains used in the bioremediation of oil-contaminated soils and inoculum II contained bacteria isolated from soil samples previously bioremediated at pH = 5, 7 and 9. Biodegradation was observed in all the investigated media independently of initial pH value and type of inoculum used.

Biotransformation of phosphogypsum by bacteria isolated from petroleum-refining wastewaters.

The biotransformation of phosphogypsum in cultures of sulfate-reducing bacteria (SRB) isolated from crude petroleum-refining wastewaters or purified using activated sludge method was studied. Selection was with the microcosms method on Postgate and minimal medium with different carbon sources, Emerson medium and petroleum-refining wastewaters. Highest hydrogen sulfide production, in excess of 500 mg/L, was observed in culture of microorganisms isolated from purified petroleum-refining wastewaters in Postgate medium with phenol as sole carbon source.

Effect of nitrates on biotransformation of phosphogypsum and phenol uptake in cultures of autochthonous sludge microflora from petroleum refining wastewaters.

The effect of nitrates on the biotransformation of phosphogypsum at 30 degrees C in stationary cultures of anaerobic, heterogeneous microflora growing in medium with phenol (250-1,000 mg/L) as sole carbon source was studied. The microorganisms used in this study were isolated from sludge in biological petroleum-refining wastewater treatment plant. Phosphogypsum (a waste product in the chemical industry that contains approximately 95% CaSO4) was added in amount of 5 g/L, the source of nitrates was KNO3 in concentration equivalent to that of phenol (250-1,000 mg N-NO3/L).