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Desperate Times Call for Desperate Measures

Sporulation in Bacillus subtilis


Justin A. Pruneski
Department of Biological and Environmental Sciences
Heidelberg University


This interrupted case study introduces the topic of bacterial sporulation and cannibalism in Bacillus subtilis. The storyline follows Susan and her lab mates who are presenting research at a lab meeting when Susan falls asleep and dreams they are stranded on a deserted island. She makes connections between their fight for survival in the dream and the survival mechanisms of the bacteria they study in the lab. The benefits of sporulation under conditions of sustained stress are fairly obvious, but Susan's dream is used to examine the idea that sporulation may not always be beneficial and that bacteria would not want to commit to entering such a state in response to temporary stresses. Through the analysis of actual data from the scientific literature, students uncover a mechanism by which B. subtilis delays its commitment to sporulation by killing members of its own species to release nutrients (i.e., cannibalism). Originally developed for a general undergraduate microbiology course when discussing the structure and growth of prokaryotic cells, the case could also be used in an introductory biology course that emphasizes bacteria and data literacy.

  • Describe the process of endospore formation in Bacillus subtilis.
  • Identify both the benefits and potential risks associated with sporulation as a survival mechanism.
  • Analyze and interpret data and figures from the scientific literature.
  • Determine the mechanism for how B. subtilis delays sporulation.
  • Construct a figure to explain the mechanism of cannibalism during B. subtilis sporulation.
  • Appreciate the complex developmental pathways bacteria can undergo.
Keywords: Bacillus subtilis; bacteria; cannibalism; endospore; microbiology; sporulation; survival;
Topical Area: N/A
Educational Level: Undergraduate lower division, Undergraduate upper division
Formats: PDF
Type/Method: Interrupted
Language: English
Subject Headings: Microbiology  
Date Posted: 6/7/2016
Date Modified: N/A
Copyright: Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

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