The use of lactose as inducer for the expression of dextransucrase was investigated in high density of Escherichia coli. Different culture conditions including carbon source, nitrogen sources, inorganic salts, inoculum density (OD 600 ) and lactose concentrations were optimized, and high-level expression of dextransucrase in E. coli was achieved via an optimal culture conditions. The results in...

Term Definition alga(e) Primitive, often aquatic, plants that carry on photosynthesis but lack the flowers, roots, stems, and leaves of higher plants. algal bloom High concentrations or densities of algae. allopathy The suppression of growth of an organism by another due to the release of a toxic substance. amino acids The building blocks for the synthesis of proteins. Can be a source of nitrog...

Floral nectars are rich in energy but contain only traces of amino acids, and it has been hypothesized that arthropods may be an important source of energy and amino acids for hummingbirds. We studied the nitrogen requirements of hummingbirds as well as how they use small arthropods to satisfy their nitrogen and energy requirements and how organ mass varies with nitrogen intake. Non-reproductiv...

dissolved organic nitrogen (don) is an important constituent of dissolved organic matter (dom). it has a considerable effect on total dissolved soil nitrogen and it is very important as a nitrogen source of many aquatic and terrestrial ecosystems. dissolved inorganic nitrogen, which is another form of total soil dissolved nitrogen, includes no3, no2 and nh4, which is very important for plant nu...

The potentially toxic freshwater cyanobacterium Cylindrospermopsis raciborskii has become increasingly prevalent in tropical and temperate water bodies worldwide. This paper investigates the effects of different nitrogen sources (NO3-, NH4+, and omission of a fixed form of nitrogen) on the growth rates, morphologies, and cylindrospermopsin (CYL) concentrations (expressed as a percentage of the ...

Isolation of bacteria able to utilize s-triazines as the sole and limiting nitrogen sources for growth is described. Three strains of Pseudomonas (A, D, and F) and two strains of Klebsiella pneumoniae (90 and 99) were examined. Strains D and F utilized N-ethylammelide, N-isopropylammelide, ammeline, ammelide, cyanuric acid, and ammonium ion as nitrogen sources. Strain A utilized melamine, ammel...

A study has been made of the distribution and properties of the free amino acid pool in yeast. The depletion of the pool was found to depend upon the energy source used, conditions of growth, and the nature of the exogenous nitrogen source. Pool levels could be restored either by an internal replenishment mechanism or by various nitrogen sources. In the absence of internal replenishment a stron...

Soybean is an important crop, with processed soybeans being the second largest source of vegetable oil and the largest source of animal protein feed in the world. Nodules on soybean roots are responsible for symbiotic nitrogen fixation, enabling soybean plants to obtain sufficient nitrogen for growth and seed production. Because nitrogen is an essential, but often limiting, nutrient for plant g...