How does endospore help bacteria survive

One side then engulfs the other. Endospores enable bacteria to lie dormant for extended periods, even centuries. When the environment becomes more favorable, the endospore can reactivate itself to the vegetative state. Examples of bacteria that can form endospores include Bacillus and Clostridium. Endospores can survive without nutrients. They are resistant to ultraviolet radiation, desiccation, high temperature, extreme freezing and chemical disinfectants.

They are commonly found in soil and water, where they may survive for long periods of time. Bacteria produce a single endospore internally. Viewing endospores under the light microscope can be difficult due to the impermeability of the endospore wall to dyes and stains. While the rest of a bacterial cell may stain, the endospore is left colorless.

To combat this, a special stain technique called a Moeller stain is used. That allows the endospore to show up as red, while the rest of the cell stains blue.

As a cell begins the process of forming an endospore, it divides asymmetrically Stage II. This results in the creation of two compartments, the larger mother cell and the smaller forespore. These two cells have different developmental fates.

Intercellular communication systems coordinate cell-specific gene expression through the sequential activation of specialized sigma factors in each of the cells. Next Stage III , the peptidoglycan in the septum is degraded and the forespore is engulfed by the mother cell, forming a cell within a cell.

Finally, the mother cell is destroyed in a programmed cell death, and the endospore is released into the environment. The endospore will remain dormant until it senses the return of more favorable conditions. Some Epulopiscium -like surgeonfish symbionts form mature endospores at night. These spores possess all of the characteristic protective layers seen in B. These are the largest endospores described thus far, with the largest being over times larger than a Bacillus subtilis endospore.

The formation of endospores may help maintain the symbiotic association between these Epulopiscium -like symbionts and their surgeonfish hosts.

Another method, freeze-drying, involves drying the microorganisms under a vacuum. This preserves most bacteria for many years. Researchers do not completely understand the mechanisms that contribute to cell survival under adverse conditions. But maintaining the proteins of the cell in an active form is clearly critical to survival. Keeping a very low level of water inside the cell appears to be likewise essential to long-term survival. Spores, endospores, cysts and desiccated cells all have low water content.

Freezing itself does not usually harm cellular components. Ice crystals, however, are lethal to living cells. Therefore, removing waterespecially while the cells are cold, as is done in freeze-dryingwill usually keep the proteins active. Many bacteria can also be stored frozen at ultracold degrees Celsius temperaturesthe secret is to add a substance like glycerol that prevents the formation of ice crystals. Although scientists do know something about the survival mechanisms of organisms that have been studied for many years, we still have a long way to go.

Indeed, for the vast number of bacteria that cannot be cultured in the laboratoryincluding many that live in microbial communities, which may offer them some protectionwe know very little about the means by which they persist in the often hostile microbial world. Clostridium and Bacillus are two spore-forming genera 1 , which also contain several foodborne pathogens that can cause foodborne illness in humans. These include Clostridium botulinum the cause of botulism , which can lead to paralysis and death and Bacillus cereus a common cause of diarrheal and emetic food poisoning.

Since these pathogens can form spores, they are commonly not inactivated with usual food treatment methods. For example, Clostridium botulinum is a common concern in canned food, so foods are canned using high pressure and high heat to kill spores. Another example is Bacillus cereus , which can be found in contaminated rice even after it is cooked.