THEY might be small, but don’t call them stupid. Some bacteria show great concern for their fellows, and now biologists have discovered that the social skills of one species may rest on an unusually discriminating palate for a key nutrient.
If food becomes sparse, many myxobacteria will commit suicide, and this selfless act releases raw materials that go towards protecting the others. Meanwhile, some become dormant spores that can regenerate the colony when the nutrient crisis has passed.
A variety of environmental factors can trigger this collective response, but the most important is the level of phosphates – basic chemicals that are key to the health of any microbe. David Whitworth of the University of Warwick in the UK and Mitchell Singer of the University of California, Davis, have found that Myxococcus xanthus has four distinct biochemical signalling pathways that interact to detect phosphates and make decisions based on their availability. Most other bacteria only seem to have one such pathway.
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In total, M. xanthus has around 150 biochemical signalling pathways. Whitworth suggests they interact to give flexibility in responding to the environment. He will present his findings at next week’s meeting of the Society for General Microbiology.
