Analysis of Peptidoglycan Structural Changes and Cortex Lytic Enzymes during Germination of<i> Bacillus anthracis</i> Spores

Sporulation is a process of differentiation that allows capable cells to go into a dormant and resistant stage of life. To become active again, the spores must germinate into vegetative cells. One key process in spore germination is hydrolysis of the cortex peptidoglycan. This process has been studied in a variety of sporulating species; however, it has not been studied in <i>Bacillus anthracis</i>. A clear understanding of cortex degradation may provide information that will allow for better cleanup of spore contaminated sites. The structure of cortex peptidoglycan of <i>Bacillus anthracis</i> was characterized. The peptidoglycan of the dormant spores was extracted, digested with Mutanolysin, and analyzed using HPLC to determine the structure. The analyses revealed that the cortex peptidoglycan of <i>B. anthracis</i> was very similar to other <i>Bacillus sp.</i>. Spores were stimulated to germinate and cortex peptidoglycan was extracted and analyzed at various times. <i>Bacillus anthracis</i> appeared to hydrolyze its cortex more rapidly than other <i>Bacillus </i>species. While the spores of three species release the spore solute dipicolinic acid and resume metabolism at similar rates, the <i>B. anthracis </i> spores released 75% their cortex material within 10 minutes while the other species released only 20% in the same time frame. This suggests that the <i>B. anthracis</i> spore coats are more permeable to cortex fragments than those of the other species, or that <i>B. anthracis</i> rapidly cleaves the cortex into smaller fragments. Novel cortex fragments analyzed during <i>B. anthracis</i> germination were produced by a glucosaminidase; however, additional studies need to be performed for confirmation.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biology

Department dc:contributor.department

Biology

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2005

Author dc:creator

• Dowd, Melissa Margaret

Chair dc:contributor.committeechair

• Popham, David L.

Committee members dc:contributor.committeemember

• Seyler, Richard
• Yang, Zhaomin

• Bacillus anthracis
• peptidoglycan
• cortex
• germination

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-09202005-091222

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/44886