Where is Dipicolinic acid found?
Dipicolinic acid (DPA) comprises ∼10% of the dry weight of spores of Bacillus species. Although DPA has long been implicated in spore resistance to wet heat and spore stability, definitive evidence on the role of this abundant molecule in spore properties has generally been lacking.
What are prokaryotic endospores?
Some prokaryotes form spores for survival. Called endospores, they form inside prokaryotic cells when they are under stress. The stress could be UV radiation, high temperatures, or harsh chemicals. Endospores enclose the DNA and help it survive under conditions that may kill the cell.
Are bacterial endospores asexual?
Endospores are asexual cells that are formed within single cells and in hyphae, and seem to arise by budding (Fig. 7.1). Unlike chlamydospores and ascospores, endospores cannot be selectively stained.
Is Dipicolinic acid a protein?
Dipicolinic acid is a compound unique to spores that will comprise up to 15% of the dry weight of the mature structure [110]. SpoVA, a membrane-associated protein transcribed from a σG promoter, binds the dipicolinic acid in order to bring it into the forespore [111].
Are endospores only in Gram-positive bacteria?
An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Firmicutes. Endospore formation is usually triggered by a lack of nutrients, and usually occurs in gram-positive bacteria.
What is the importance of Dipicolinic acid in bacterial endospore?
The center of the endospore, the core, exists in a very dehydrated state and houses the cell’s DNA, ribosomes and large amounts of dipicolinic acid. This endospore-specific chemical can comprise up to 10% of the spore’s dry weight and appears to play a role in maintaining spore dormancy.
How are endospores destroyed?
While significantly resistant to heat and radiation, endospores can be destroyed by burning or by autoclaving at a temperature exceeding the boiling point of water, 100 °C. Prolonged exposure to ionising radiation, such as x-rays and gamma rays, will also kill most endospores.
Are bacterial endospores destroyed?
While significantly resistant to heat and radiation, endospores can be destroyed by burning or by autoclaving at a temperature exceeding the boiling point of water, 100 °C. Endospores are able to survive at 100 °C for hours, although the larger the number of hours the fewer that will survive.
Do endospores have Exosporium?
Endospores are composed of the DNA-containing core surrounded by a cortex, spore coat and exosporium [84–86], all of which protect the dormant cell from hostile and unfavourable conditions such as desiccation, osmotic shock, extremes of temperature and contact with chemicals such as disinfectants.
What is the role played by Dipicolinic acid in sporulation?
Biological role Dipicolinic composes 5% to 15% of the dry weight of bacterial spores. Dipicolinic acid forms a complex with calcium ions within the endospore core. This complex binds free water molecules, causing dehydration of the spore. As a result, the heat resistance of macromolecules within the core increases.
What kind of bacteria produce dipicolinic acid?
Dipicolinic acid. Two genera of bacterial pathogens are known to produce endospores: the aerobic Bacillus and anaerobic Clostridium. The high concentration of DPA in and specificity to bacterial endospores has long made it a prime target in analytical methods for the detection and measurement of bacterial endospores.
How does dipicolinic acid affect the endospore core?
Dipicolinic acid forms a complex with calcium ions within the endospore core. This complex binds free water molecules, causing dehydration of the spore. As a result, the heat resistance of macromolecules within the core increases. The calcium-dipicolinic acid complex also functions to protect DNA from heat denaturation by inserting…
Where is DPA located in a bacterial endospore?
In the present study, a protocol for the quantification of dipicolinic acid (DPA; pyridine-2,6-dicarboxylic acid) was developed. DPA is a universal, but specific, component of bacterial endospores ( Powell, 1953 ). It has been shown that DPA is located in the core, representing 5–14% of endospore dry weight ( Murrell, 1969 ).
What is the standard state of dipicolinic acid?
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). ?) Dipicolinic acid ( pyridine-2,6-dicarboxylic acid or PDC and DPA) is a chemical compound which plays a role in the heat resistance of bacterial endospores.
