Chapter 8 Cell wall changes during bacterial endospore formation

This chapter discusses the cell wall changes during bacterial endospore formation. Bacterial endospore formation is a primitive cellular differentiation that is induced by nutrient depletion. An early stage is an asymmetrically located division which yields two distinct cells that have radically different developmental fates. The smaller cell is engulfed by the larger cell and develops into the mature spore; the mother cell ultimately lyses. The mature spore is characterized by its resistance to a variety of environmental stresses. There are several periods when wall metabolism during the developmental cycle is substantially different from vegetative wall metabolism; some of these involve new wall synthesis whereas others are degradative. Early microscopy studies enabled investigators to identify a series of intermediates in the morphological transition from vegetative cell to spore; these stages are now conventionally designated with Roman numerals, with the vegetative bacterium designated stage 0. There are three periods of peptidoglycan synthesis during sporulation. These correspond to (1) synthesis of a small amount associated with spore septum formation, (2) synthesis of the PGCW which is quite similar to vegetative wall, and (3) synthesis of the cortex.