by Tom Bernhardt
Waste not, want not, as the old saying goes. Bacteria have apparently heeded this advice for some time, and this is no doubt one reason why they are such successful organisms. Perhaps we humans should take notes.
This spotlight on the recent literature is to point your attention to a recent review article by James (Ted) Park and Tsuyoshi Uehara in Microbiology and Molecular Biology Reviews entitled How Bacteria Consume Their Own Exoskeletons (Turnover and Recycling of the Cell Wall Peptidoglycan).
Amazingly, as bacterial cells grow, they turn over a significant percentage of their total cell wall material every generation. In their review, Park and Uehara chronicle the history of the elegant detective work that led to our current understanding of how E. coli reuses and recycles these cell wall turnover products for building new wall material or for consumption as an energy source. These pathways were largely worked out by the superb biochemical and genetic experiments performed in Ted Park's lab over the years and have important implications in cell physiology, cell signaling, antibiotic resistance, and immune recognition of bacteria.
Much of what we know about the synthetic pathway of the bacterial cell wall and the mode of action of penicillin can be traced to his early work. In the 1950’s, he found that penicillin treatment of staphylococci results in the accumulation of the sugar-nucleotide precursors of the peptidoglycan biosynthetic pathway. In one fell swoop, he discovered both the mode of action of penicillin (along with J. Strominger) and the biochemical basis for cell wall synthesis. Ted has continued to work in this area and to make important contributions to this field.
Tom Bernhardt is Assistant Professor in the Department of Microbiology and Molecular Genetics at Harvard Medical School