Search results
Results From The WOW.Com Content Network
Cytolysis, or osmotic lysis, occurs when a cell bursts due to an osmotic imbalance that has caused excess water to diffuse into the cell. Water can enter the cell by diffusion through the cell membrane or through selective membrane channels called aquaporins, which greatly facilitate the flow of water. [ 1 ]
For this, they forced E. coli planktonic cells into a swarming-cell-phenotype by inhibiting cell division (leading to cell elongation) and by deletion of the chemosensory system (leading to smooth swimming cells that do not tumble). The increase of bacterial density inside the channel led to the formation of progressively larger rafts.
Generally, turgor pressure is caused by the osmotic flow of water and occurs in plants, fungi, and bacteria. The phenomenon is also observed in protists that have cell walls. [ 3 ] This system is not seen in animal cells, as the absence of a cell wall would cause the cell to lyse when under too much pressure. [ 4 ]
Run-and-tumble motion is a movement pattern exhibited by certain bacteria and other microscopic agents. It consists of an alternating sequence of "runs" and "tumbles": during a run, the agent propels itself in a fixed (or slowly varying) direction, and during a tumble, it remains stationary while it reorients itself in preparation for the next run.
Bacterial morphological plasticity refers to changes in the shape and size that bacterial cells undergo when they encounter stressful environments. Although bacteria have evolved complex molecular strategies to maintain their shape, many are able to alter their shape as a survival strategy in response to protist predators, antibiotics, the immune response, and other threats.
This optimal temperature assists in the chemical breakdown of the tissue and promotes microorganism growth. Decomposition nearly stops below 0 °C (32 °F) or above 48 °C (118 °F). Moisture and air exposure: Putrefaction is ordinarily slowed by the body being submerged in water, due to diminished exposure to air.
In this response, bacterial cells can secrete extracellular polymeric substances to form a film that can provide support to the bacterial colony, such as by improving their ability to adhere to a surface. [4] Another common stress response is latency. In a latent states, a cell will slow down its metabolism and become virtually dormant.
When the rains return and soils become wet, the osmotic gradient between the bacterial cells and the soil water causes the cells to gain water quickly. Under these conditions, many bacterial cells burst, releasing a pulse of nutrients. [64] Decomposition rates also tend to be slower in acidic soils. [64]