Bacterial Endospores and Sporulation

These flashcards cover the structure, chemical composition, formation process (sporulation), and practical significance of bacterial endospores based on the lecture notes.

Endospore

A survival structure produced by certain rod-shaped, gram-positive bacteria that allows the organism to survive stressful conditions and be dispersed to new locations.

Core

The part of an endospore containing the cytoplasm, DNA, and cytoplasmic membrane, surrounded by a core wall.

Cortex

An endospore layer made up of loose cross-linked peptidoglodyn layers.

Spore coat

A structure consisting of many layers of spore-specific proteins.

Exosporium

The outermost layer of an endospore, consisting of a thin protein shell.

Dipicolonic acid

A chemical enriched with $Ca^{2+}$ found only in the core of the spore that makes up $10\%$ of the dry weight, helps dehydrate the cell, and protects DNA from heat damage by intercalating between bases.

SASPs (Small Acidic Soluble Proteins)

Proteins that bind to and compact DNA to increase resistance to UV radiation, heat, and desiccation, while also serving as an energy source during germination.

Sporulation

The production of spores, taking around $6-14$ hours and requiring the coordination of $200+$ genes, typically occurring during the stationary phase triggered by stress.

Spo0A

A protein produced by a cell that secretes a toxin to lyse nearby cells that have not activated it, releasing nutrients to fuel endospore production.

Activation

The first stage of returning to a vegetative state, occurring once the cause of sporulation is removed, such as through warming at elevated but sublethal temperatures.

Germination

A stage taking a few minutes where the spore begins returning to a vegetative cell and resources like SASPs are broken down.

Outgrowth

The stage involving rapid water uptake, synthesis of new DNA, RNA, and proteins, and the swelling and emergence of a new vegetative cell from the broken spore.

Clostridium

A genus of bacteria that forms endospores in response to oxygen because they lack the genes to encode enzymes required to deal with the toxic chemical.

Bacillus anthracis

The bacterial species used in 2001 biological warfare letters, chosen for its resistance to disinfectants, lightweight dispersal, and ability to cause disease when inhaled.

Terbium

A chemical used to detect and identify endospores in soil by reacting with dipicolonic acid.