The effects of long-chain (C(12) to C(18)) quaternary ammonium compounds (QACs) on the density, heterotrophic activity, and biodegradation capabilities of heterotrophic bacteria were examined in situ in a lake ecosystem. Monoalkyl and dialkyl substituted QACs were tested over a range of concentrations (0.001 to 10 mg/liter) in both acute (3 h) and chronic (21 day) exposures. In general, none of...

This study explores the role of transparent exopolymer particles (TEP) as an additional carbon source for heterotrophic microbial activity in the eutrophic Qishon estuary. From the coastal station and upstream the estuary; TEP concentrations, β-glucosidase activity, bacterial production and abundance have gradually increased. TEP were often found as bio-aggregates, scaffolding algae, detritus m...

abstract heterotrophic seedling growth has described as the product of the following dynamic and to transmit seed reserves and the conversion efficiency of mobilized seed reserves to seedling tissue. this research was carried out to evaluate germination and seedling growth of wheat seed (n8019) in the form of combined analysis design with crd arrangement. treatments consisted of 4 levels of wat...

This study was carried out in two hypersaline lakes (Acı and Meke Lakes) Turkey to understand the diversity geographic distribution of free-living heterotrophic flagellates. Heterotrophic flagellates environments have not previously been studied Turkey. We found seventeen morphospecies with one unidentified protist. The observed species belong Craspedida, Heterolobosea, Apusomonadida, Neobodoni...

UNLABELLED The ability to reduce atmospheric nitrogen (N2) to ammonia, known as N2 fixation, is a widely distributed trait among prokaryotes that accounts for an essential input of new N to a multitude of environments. Nitrogenase reductase gene (nifH) composition suggests that putative N2-fixing heterotrophic organisms are widespread in marine bacterioplankton, but their autecology and ecologi...

Theory suggests that variation in the attractive solvation force associated with cell-surface hydrophobicity can significantly affect contact rates among small cells in aqueous environments and consequently may influence rates and selective impacts of marine nanoflagellate grazers feeding on picoplankton assemblages. To investigate this hypothesis, we assayed the natural range in hydrophobic ch...

Subglacial microbial habitats are widespread in glaciated regions of our planet. Some of these environments have been isolated from the atmosphere and from sunlight for many thousands of years. Consequently, ecosystem processes must rely on energy gained from the oxidation of inorganic substrates or detrital organic matter. Subglacial Lake Whillans (SLW) is one of more than 400 subglacial lakes...

Heterotrophic bacteria were studied which produced nitrite in the presence of ammonia and in the absence of nitrate. A soil extract medium was prepared which allowed good growth as well as nitrite production in the absence of nitrate. Quantitative data are recorded showing that ammonia decreases as nitrite accumulates when four different cultures are grown in the soil medium. Resting cell studi...