Vegetative cells

Antiseptic. An antiseptic is a chemical substance that prevents or inhibits the action or growth of microorganisms but may not necessarily kill them, and is used topically on living tissue. The distinction between a disinfectant and an antiseptic is that the former is expected to kill all vegetative cells and is used only on inanimate objects, whereas the latter may not kill all cells and is used on the body. 

Ethylene oxide is able to inactivate all microorganisms. Bacterial spores are more resistant than vegetative cells, yeasts, and molds (287). Spores are 5 to 10 times more resistant than the vegetative cells (288). bacillus subtilis spores were the most resistant of those tested (289). Ethylene oxide was also shown to be vimcidal (290). 

Vegetative cell Cells involved with obtaining nutrients, as opposed to reproduction or resting. 

Bacillus thuringiensis produces a variety of organic compounds which are toxic to the larvae of certain susceptible insect hosts. Among the toxic entities are proteinaceous crystals, probably three soluble toxins, and certain enzymes. The protein material is the major toxin active in killing lepidopterous larvae. The protein is formed by the cells apparently in close synchrony with sporulation, and its nature is a constant function of bacterial strain. The mode of action of the protein is under study. The sequence of events in the pathology observed is probably solubilization of the crystal (enzymatic or physical)—>liberation of toxic unit—>alteration of permeability of larval gut wall— change in hemolymph pH—>invasion of hemolymph by spores or vegetative cells of the bacterium. 

The bacterial culture converts a portion of the supplied nutrient into vegetative cells, spores, crystalline protein toxin, soluble toxins, exoenzymes, and metabolic excretion products by the time of complete sporulation of the population. Although synchronous growth is not necessary, nearly simultaneous sporulation of the entire population is desired in order to obtain a uniform product. Depending on the manner of recovery of active material for the product, it will contain the insolubles including bacterial spores, crystals, cellular debris, and residual medium ingredients plus any soluble materials which may be carried with the fluid constituents. Diluents, vehicles, stickers, and chemical protectants, as the individual formulation procedure may dictate, are then added to the harvested fermentation products. The materials are used experimentally and commercially as dusts, wettable powders, and sprayable liquid formulations. Thus, a... 

Ross, K.F.A. Billing, E. (1957). The water and solid content of living bacterial spores and vegetative cells as indicated by refractive index measurements. Journal of General Microbiology, 17, 418-25. 

Figure 7A. The toxigenic dinoflagellate Alexandrium sp. from Southeast Alaska. Two vegetative cells of clone EC06, from Elfin Cove. Bar is 30 xm. Photomicrography by R. A. Horner.

Table 2 Density of green vegetative cells and non-motile cysts (aplanospore) in batch cultures...

Superficial gas velocity (cm s ) Vegetative cell (xlO cellmU ) Cyst (xlO cellmL ) % of cyst... 

The vegetative cell cycle of S. cerevisiae has received extensive attention. There are many justifications for this. Firstly, the cell cycle in this organism has many convenient landmarks (Hartwell 1974, 1978 Pringle 1978) which make it very easy to identify the exact point in the cell cycle at which a cell happens to be. Examples of these landmark events include bud emergence, the size of the bud, mitosis (nuclear division takes place through the neck between the mother cell and the bud), and cell... 

Again, bacterial spores are much more resistant than vegetative cells, and their recorded resistance varies markedly depending upon their degree of dryness. In many early studies on dry heat resistance of spores their water content was not adequately controlled, so conflicting data arose regarding the exposure conditions necessary to achieve effective sterilization. This was partly responsible for variatiorrs in recommended exposure temperatures and times in different pharmacopoeias. 

Each cell consists primarily of a membrane, which separates it from the environment, preserves its structural integrity, and keeps it apart from other cells or from the surrounding environment. Plant cells, unlike animal cells, also have, in addition to a cell membrane, a cell wall, composed of cellulose and lignin. The cell wall provides structural strength not only to the vegetable cell itself but to all plant tissues as well. Inside the membrane, the interior of the cell, known as the protoplasm, includes two main... 

Cellulose, the most abundant biological substance on earth, is the basic and major component of most plant tissues it is the substance that makes up the walls of vegetable cells and therefore the framework of vegetable fibers. The molecules of cellulose are long, linear polysaccharides, made up of many (several hundreds and even over 1000) aligned glucose monomers... 

Automated pyrolysis MS analysis of lysed vegetative cells in a disinfecting suspension. 

Figure 12.3 M ALDI analysis of peptides from Bacillus subtilis sp. 168 vegetative cells prepared in situ.87 (a) Survey spectrum of peptide products. Protein assignments are listed in the figure, (b) Spectrum of product ions of unimolecular decomposition of the peptide with m z 2606.

Czerwieniec, G. A. Russell, S. C. Tobias, H. J. Fergenson, D. P. Steele, P Pitesky, M. E. Horn, J. M. Frank, M. Gard, E. E. Lebrilla, C. B. Stable isotope labeling of entire Bacillus atrophaeus spores and vegetative cells using bio-aerosol mass spectrometry. Anal. Chem. 2005, 77,1081-1087. 

Endospores. Endospores are bodies produced within the cells of a considerable number of bacterial species. They are more resistant to unfavorable environmental conditions, such as heat, cold, desiccation, osmosis, and chemicals, than the vegetative cells producing them. However, it is debatable if such extreme conditions -actually occur in nature. For instance, the resistance of spores to high temperatures is a laboratory phenomenon and probably never occurs in a natural environment. 

Spores may be spherical, ellipsoidal, or cylindrical in shape. The position of the spore in a cell may be central, subterminal, or terminal. A fully grown spore may have a diameter greater than that of the vegetative cell. This causes a bulging of the cell. The resulting forms are known as Clostridium if central, and plectridium if terminal. As a rule, each species has its own characteristic size, shape, and position of the spore, but this is subject to variation under different environmental conditions. 

Ross and Billing, by means of refractive index measurements on spores and vegetative cells of B. cereus, B. cereus var. mycoides, and B. megaterium, found the values to be very high and comparable with that of dehydrated protein. This suggested that they contained much less water than the vegetative cells. 

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