Matsumoto 7 - 3 . Spore and sporulation

The soil bacterium Bacillus subtilis must cope with the environmental change including availability of nutrients, temperature, salinity, pH, antibiotics, toxins, bacteriophage, radiation, and other factors capable of damaging cells. Therefore, B. subtilis cells are equipped with a genetically regulated program to adapt to these changes. Recently, several instance of multicellular behavior of bacteria to maximize their survival are revealed. Spore formation is the ultimate surviving strategy for longtime, which is distinct physiological state form vegetative cells. Sporulation involves a highly ordered program of gene expression and morphological change. Intercellular signal transduction and compartment-specific gene expression brings about maturation of the spore. Mature spores remain for long periods of starvation and are resistant to several environmental insults. These properties are attributed mainly to the unique figures of spore’s outer layers, spore coat and cortex, as well as to the physical state of spore cytoplasm. In this chapter, we describe about surviving strategies, regulation of spatiotemporal gene expression during sporulation, and structure and resistance of the spores of B. subtilis. Correspondence/Reprint request: Dr. Kazuhito Watabe, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka 573-0101, Japan. E-mail: [email protected] Daisuke Imamura & Kazuhito Watabe 262