1. MICROBIOLOGIA GENERALE Structure and function of prokaryotic cells 4

2. Structure and function of prokaryotic cells: the endospore

3. Differences between endospores and vegetative cells

6. Staining bacterial endospores (Schaeffer-Fulton - malachite green)

7. Structure of the bacterial endospore

10. Dipicolinic acid (DPA): (a) Structure of DPA. (b) How Ca 2+ cross-links DPA molecules to form a complex.

11. Endospore development: an example of cell differentiation

13. Stages of endospore formation

14. Sporulation requires that a special program of sequential events take place. This program involves changes in gene expression as some genes are turned on and others are turned off in turn. Bacillus subtilis uses different RNA polymerases each containing a different sigma subunit to express the genes required for each event  factor GeneFunction AA sigAvegetative factor BB sigB CC sigC DD sigDflagellin EE spoIIGmother cell FF spoIIACforespore GG spoIIICforespore HH spo0Hinitiation of sporulation KK spoIVCBmother cell LL sigL

15. The initiation of sporulation: the phosphorelay

16. Stages II-IV of sporulation: compartmentalization and  -factor cascades

17. Endospore germination

18. Mature endospore Activation and germination Outgrowth New vegetative cell

19. Bacillus thuringiensis viewed by phase contrast microscopy The vegetative cells contain endospores (phase bright) and crystals of an insecticidal protein toxin (delta endotoxin). Most cells have lysed and released the spores and toxin crystals (the structures with a bipyramidal shape).

21. Bacillus thuringiensis deposit and killed gypsy moth larvae on foliage

23. Mechanism of toxicity of Bt

25. Bacillus thuringiensis as a natural insecticidal

26. Mixobacteria differentiation

27. Streptomyces differentiation