IGEM:IMPERIAL/2009/Encapsulation/Phase2

Sporulation

An endospore is a dormant, tough, and non-reproductive structure produced by Gram-positive bacteria. They form through the production of an encapsulating spore coat within the spore-forming cell. Examples include Bacillus and Clostridium.
Spor

Sporulation and E.coli

E.coli is non-sporulating. Therefore the idea to clone the genes for sporulation from Bacillus subtilis into E.coli was investigated. A paper (below) used the amino-acid sequence deduced from the nucleotide sequence of the spolIAC gene of Bacillus subtilis which has been shown to be homologous to that of the sigma subunit of the Escherichia coli RNA polymerase. Results show that this gene can be cloned in E. coli only under conditions in which it is not expressed.

E.coli and sporulation.

The sigma-like products of the sporulation gene spolIA C of Bacillus subtilis is toxic to Escherichia coil.
The main chassis we would therefore use is B.subtilis.

It is now agreed that spore formation in bacteria is a form of differentiation in which there is an ordered, temporal sequence of events and a degree of commitment.

Bacteria will produce a single endospore internally. The spore is sometimes surrounded by a thin covering known as the exosporium, which overlies the spore coat. The spore coat, which acts like a [sieve] that excludes large toxic molecules like lysozyme, is resistant to many toxic molecules and may also contain enzymes that are involved in germination. The cortex lies beneath the spore coat and consists of peptidoglycan. The core wall lies beneath the cortex and surrounds the protoplast or core of the endospore. The core contains the spore chromosomal DNA which is encased in chromatin-like proteins known as SASPs, that protect the spore DNA from UV radiation and heat. The core also contains normal cell structures, such as ribosomes and other enzymes, but is not metabolically active.