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A 2013 study suggested that it is possible to alter particle size and activity of extracellular biogenic nanoparticles via controlled expression of the genes encoding surface proteins. An important example is the synthesis of silver nanoparticle by S. oneidensis , where its antibacterial activity can be influenced by the expression of outer ...
Soil aeration maintains oxygen levels in the plants' root zone, needed for microbial and root respiration, and important to plant growth.Additionally, oxygen levels regulate soil temperatures and play a role in some chemical processes that support the oxidation of elements like Mn 2+ and Fe 2+ that can be toxic.
In hypertonic solutions water flows out of the cell and the cell shrinks (plasmolysis). In hypotonic solutions, water flows into the cell and the cell swells ( turgescence ). Osmotic shock or osmotic stress is physiologic dysfunction caused by a sudden change in the solute concentration around a cell , which causes a rapid change in the ...
Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated.
In the soil, acidification reduces microbial and macrofaunal diversity. [31] This can reduce soil structure decline which makes it more sensitive to erosion. There are less nutrients available in the soil, larger impact of toxic elements to plants, and consequences to soil biological functions (such as nitrogen fixation). [32]
where Ci is the salt concentration of the irrigation water, Cc is the salt concentration of the capillary rise, equal to the salt concentration of the upper part of the groundwater body, Fc is the fraction of the total evaporation transpired by plants, Ce is the salt concentration of the water taken up by the plant roots, Cp is the salt ...
Environmental conditions such as soil pH, [18] soil temperature, [19] moisture content, [20] and plant litter type and quality [21] have the potential to alter exoenzyme expression and activity. Variations in seasonal temperatures can shift metabolic needs of microorganisms in synchrony with shifts in plant nutrient requirements. [ 22 ]
The water content of most vegetal detritus ranges from 60% to 90%. The dry matter consists mainly of carbon, oxygen, and hydrogen. Although these three elements make up about 92% of the dry weight of the organic matter in the soil, other elements present are essential for the nutrition of plants, including nitrogen, phosphorus, potassium ...