Difference WikiBiology

Difference Between Endospore and Exospore

Main Difference

The main difference between Endospore and Exospore is that Endospore is formed in the parent cell wall and set free to the environment when cell rupture, whereas Exospore is formed through the cell division and is parted from the mother cell through the formation of the septum.

Endospore vs. Exospore

An endospore is considered as a structure that is produced by the bacteria consisting of DNA and a small amount of cytoplasm to survive under unfavorable conditions; on the other hand, Exospore is considered as an asexual spore that is detached from the mother cell through the formation of a septum. Bacteria are responsible for producing the endospores, while fungi and algae produce the exospores.

ADVERTISEMENT

Endospores usually are formed inside the parent cell; on the contrary, exospores are generally formed near the termination of a parent cell. Cell division does not occur in the formation of endospores; conversely, exospores are formed by the process of cell division. The structure of the endospore is sturdy, dormant, and non-reproductive, which is sometimes covered by a thin covering known as exosporium. In contrast, the structure of the exospore contains a unique form of spores, which is a means for the multiplication of bacteria and fungi, and they do not consist of special covering.

Through the rupturing of the parental cell, the endospores are released into the environment; on the other hand, the exospores are typically released through the budding. One organism can form only one endospore, but on the contrary, one organism can produce several exospores.

ADVERTISEMENT

Endospores can be formed by the bacterial genera such as Clostridium, Bacillus, and Paenibacillus; on the flip side, exospores are formed by the Chamaesiphon, conidiospores, Actinomyces, Stichosiphon, Streptomyces, Actinobacteria. Endospores are generally produced by the Clostridium Bacillus and Sporosarcina bacteria, while on its comparison, the exospores are usually produced by some members of the phylum Actinobacteria.

Comparison Chart

EndosporeExospore
A tough, inactive form that is formed by many bacteria that allows them to survive under unfavorable conditions like disinfectants, intense heat, and UV radiations is known as Endospore.The structure which is formed outwardly to the somatic cell through budding at the endpoint of the parent cell is known as the Exospore. It is also known as other resilient bacteria.
Considered As
A structure which is produced by the bacteria consisting of DNA and a small amount of cytoplasm to survive under unfavorable conditionsAn asexual spore that is detached from the mother cell through the formation of a septum
Formed By
Bacteria are responsible for producing the endosporesFungi and algae produce the exospores
Formation
Typically formed inside the parent cellGenerally formed near the termination of a parent cell
Cell Division
Cell division does not occurFormed by the process of cell division
Structure
The structure is tough, dormant, and non-reproductive which is sometimes covered by a thin covering known as exosporiumThe structure contains a particular form of spores which is a mean for the multiplication of bacteria and fungi, and they do not consist of special covering
Release of the Spore
Through the rupturing of the parental cell, spores are released into the environmentTypically released through the budding
From an Organism
One organism can form only one endosporeOne organism can produce several exospores
Produced By
Generally produced by the Clostridium Bacillus and Sporosarcina bacteriaUsually produced by some members of the phylum Actinobacteria
Examples
Can be formed by the bacterial genera such as Bacillus, Clostridium, and PaenibacillusFormed by the conidiospores, Chamaesiphon, Stichosiphon, Actinomyces, Streptomyces, Actinobacteria, Chamaesiphon
ADVERTISEMENT

What is Endospore?

An endospore is known as a resistant structure that is produced by bacteria to endure under severe and unfavorable conditions containing DNA and a little portion of the cytoplasm. An endospore is covered by a thin layer of the protective outer covering.

When many environmental conditions become favorable, the endospores started to germinate and form many new organisms. That is why endospores are referred to as the primary type of reproductive cells. Endospores are formed by bacterial genera such as Clostridium, Bacillus, and Paenibacillus. These bacterial genera can endure harsh conditions like high and low temperatures, UV radiations, dehydration, chemicals.

The Endospore contains a cell wall that is formed of dipicolinic acid, which provides heat resilient properties to the endospore. The bacterial endospores can be destroyed by the treatment of moist heat at 121 °C for about 15 minutes.

The name “endospore” is given, which means a spore or seed-like shape, but it is not considered as a true spore. The endospore is a tough, dormant, stripped-down structure from which the bacteria can moderate itself. The formation of endospore is customarily triggered when there is a lack of nutrients and mainly happens in gram-positive bacteria.

What is Exospore?

The exospore is known as one more resilient bacterium, which is mainly formed by algae and fungi to multiply in harsh environmental circumstances. Through the process of cell division, the exospores produce at the terminal point of the parent cell.

The exospore can be separated by the production of a septum, which occurs between the parent and the daughter cell—the exospore results in the shape of a bud. The bud can be released from the parent cell for its germination when favorable conditions come. The conidiophores are known as kinds of fungal spores, which are generally formed as exospores.

The exospores are produced by algae such as Stichosiphon and Chamaesiphon. The exospores can also be produced by bacteria such as Actinomyces, Streptomyces, and Actinobacteria. The cyanobacteria, such as Chamaesiphon, also results in the formation of exospores. The exospore is the permanent structure of single types of bacteria.

The exospores do not have a protective covering of a spore shell. Because of almost entirely adjusted metabolism of exospores and their low water content, the exospores are considered more resilient to intense heat, dehydration, chemical stress, and radiation as compared to the vegetative cell. The exospore producer is, for instance, the methane, which is typically using bacterial genus Methylosinus.

Key Differences

  1. A hard structure that is produced by bacteria to live under critical conditions, having DNA and a slight volume of cytoplasm are called the endospore. Conversely, an asexual spore, which is typically used for the multiplication of algae and fungi and that is separated from the mother cell through the formation of a septum, is called Exospore.
  2. Endospores can be produced mainly by bacteria; on the other hand, exospores can be produced primarily by fungi and algae.
  3. Endospores are produced in the parent cell, while exospores are formed at the end of the parent cell.
  4. Endospores are not formed by the cell division, but in its comparison, the formation of exospore occurs through the cell division.
  5. One endospore is formed by one organism, whereas many exospores are formed by one organism.
  6. The endospores can be released through breaking the parental cell, while exospores can be released through the process of budding.

Conclusion

The above discussion concludes that Endospore and Exospore are two types of spores. Still, they are different from each other as Endospore is primarily produced by bacteria and inside the parent cell. Exospore is formed by algae, fungi, bacteria, and cyanobacteria and produced at the end of the parent cell.

Janet White

Janet White is a writer and blogger for Difference Wiki since 2015. She has a master's degree in science and medical journalism from Boston University. Apart from work, she enjoys exercising, reading, and spending time with her friends and family. Connect with her on Twitter @Janet__White