Bacteria spore formation

Spore formation is limited almost entirely to two genera of rodshaped bacteria Bacillus (aerobic or facultatively anaerobic), and Clostridium (anaerobic or aerotolerant). With one possible exception, the common spherical bacteria do not sporulate. Some spore-bearing species can be made to lose their ability to produce spores. When the ability to produce spores is once lost, it is seldom regained. SporMation is not a process to increase bacterial numbers because a cell rarely produces more than one spore. 

In adverse conditions, some bacteria can enter a dormant state known as a spore. Spores can remain dormant for decades and can survive under extreme temperatures and other adverse environmental conditions. Unlike fungi (Chapter 20), formation of spores is not related to reproduction and is done strictly as a protective mechanism. Upon reactivation, each spore produces a single active bacteria. Spores are normally spherical or oval and are only a fraction of the size of the active (i.e., vegetative) cell. 

Spore Formation Some bacteria form spores when growth ceases due to starvation or other causes. Spores are more resistant than normal cells to heat, drying, radiation, and chemicals. Spores can remain alive for many years however, they can convert back to normal cells at proper conditions. Spore-forming bacteria are found most commonly in the soil. 

The prototypical lantibiotic, nisin, was discovered in 1928 for its antibacterial properties and has been used as a preservative in dairy products since the 1950s (1). Nisin and other lantibiotics exhibit nanomolar efficacy against many Gram-positive strains of bacteria (2), which include methicillin resistant Staphylococcus aureus, vancomycin resistant enterococci, and oxacillin resistant bacteria. On the other hand, some lantibiotics function as morphogenetic peptides rather than antibiotics and are important for spore formation in streptomycetes (3). Since the structural elucidation of nisin in the early 1970s, extensive research efforts have been directed at understanding the biosynthesis and mode of action of various lantibiotics. 

Later, Vadehra et ah (1985) investigated the effects of gossypol on the growth of a variety of bacteria and on spore formation and germination in Bacillus cereus. It has been found that gossypol has more potent... 

Typical morphogenetic processes in bacteria are sexual reproduction and spore-formation, although these phenomena constitute a small part of the total dynamics of reproduction of bacterial cells. Clearly, therefore, we cannot regard the morphogene-... 

It has been known for some time that certain types of bacteria spend a certain amount of their lifespan in a dormant state. The bacteria are then known as en-dospores , or just spores . In this state, they appear not to undergo any metabolic processes and are important particularly because of their heat resistance. The formation of spores is a highly complex process of bacterial cell differentiation. 

Another way in nature to protect various forms of life is the formation of spores. Many bacteria, fungi, plants, algae, and protozoan are known to form spores as a strategy to survive for extended periods of time in unfavorable conditions. The high resistance of spores to chemical and physical agents is explained by their multilayered structure (Fig. 3.6). This structure is practically impermeable for cytotoxic chemicals. Besides, endospores have only 20-30% of the water content of vegetative cells... 

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