Unique growth process enables disease carriers.

• Position: Bacteria

A new bacterial growth process--one that occurs at a single end or pole of the cell instead of uniform, dispersed growth along the long axis of the cell--that could have implications in the development of new antibacterial strategies has been identified by an international team of microbiologists.

Based on past detailed studies of rod-shaped bacteria such as Escherichia coil and Bacillus subtilis, it has been assumed that most bacteria grow by binary fission, a dispersed mode of growth involving insertion of new cell wall material uniformly along the long axis of the cell. Growth requires breaking the cell wall at numerous places along the cylinder to allow insertion of new cell wall material, enabling uniform elongation of the cell. with the process culminated by cleavage at the midpoint of the cell to create two symmetric new cells.

The research, published in Proceedings of the National Academy of Sciences. reports on the surprising discovery that cell growth in a large group of rod-shaped bacteria occurs by insertion of new cell wall material only at a single end, or pole. of the cell rather than by the dispersed mode. The cell wall of the progenitor cell remains largely intact, and all of the new cell wall material is partitioned into the new cell.

The process may act as an aid in anchoring damaged material to only the aging mother cell. It could serve as a tool for conservation of energy by constraining growth to a single region of the cell. as well as ensuring that newborn cells are composed of newly synthesized outer membrane proteins, which may help...