LIVERMORE, Calif. -- Tapping into the unknown world of awakening dormant bacterial spores, researchers have revealed through atomic force microscopy (AFM) the alterations of spore coat and germ cell wall that accompany the transformation from a spore to a vegetative cell.
When starved of nutrients Bacillus (rod-shaped bacteria) cells initiate a series of genetic, biochemical and structural events that result in the formation of metabolically dormant spores. They can remain dormant for extended periods and, partly because of their tough spore coat, have a significant resistance to extreme environmental factors including heat, radiation and toxic chemicals. However, once in favorable conditions, spores break the dormant state through germination and reenter the vegetative mode of replication.
Although significant progress has been made in understanding the biochemical and genetic bases of the spore germination process, it is still unclear how a spore breaks out of its dormant state.
But a new in vitro study of single germinating Bacillus atrophaeus spores details how the spore coat structures break down, and it shows with unprecedented resolution how the new bacterium emerges from the disintegrating spore. The new research, led by Lawrence Livermore National Laboratory scientists, appears in the May 28-June 1 early online edition of the Proceedings of the National Academy of Sciences. The research appears in this weeks (June 4) issue of PNAS.
A thorough understanding of spore germination is important for the development of new countermeasures that identify the earliest stages of a wide range of spore mediated diseases, including botulism, gas gangrene and pulmonary anthrax, said Alexander Malkin, senior author from LLNLs Biosciences and Biotechnology Division. But its also important to gain fundamental insights into the key events in bacterial cell development.