Wednesday, February 02, 2022

Bacteria build communities using chemical signals comparable to radio waves

Amazing stuff! Complex communication among bacteria for 10-20 generations!

"... But biofilm communities have important implications for human health, from causing illness to aiding digestion. And they play a role in a range of emerging technologies meant to protect the environment and generate clean energy.
New UCLA-led research could give scientists insights that will help them cultivate useful microbes or clear dangerous ones from surfaces where biofilms have formed — including on tissues and organs in the human body. The study, published in the Proceedings of the National Academies of Science, describes how, when biofilms form, bacteria communicate with their descendants using a chemical signal analogous to radio transmissions. 
The investigators showed that concentration levels of a messenger molecule called cyclic diguanylate, or c-di-GMP, can increase and decrease in well-defined patterns over time, and across generations of bacteria. Bacteria cells employ those chemical signal waves, the study found, to encode information for their descendants that helps coordinate colony formation. ...
The study adds new dimensions to the scientific understanding of the mechanisms that lead to biofilms. The current paradigm, established over the last 20 years or so, holds that when a bacterium senses a surface, that cell begins producing c-di-GMP, which in turn causes the bacterium to attach to the surface. Indeed, biofilm cells generally have higher levels of c-di-GMP than bacterial cells that move around a lot.
Biofilm research focusing on bacteria’s ability to communicate from one generation to another was pioneered ... in a 2018 publication. ..."

From the abstract:
"Work on surface sensing in bacterial biofilms has focused on how cells transduce sensory input into cyclic diguanylate (c-di-GMP) signaling, low and high levels of which generally correlate with high-motility planktonic cells and low-motility biofilm cells, respectively. Using Granger causal inference methods, however, we find that single-cell c-di-GMP increases are not sufficient to imply surface commitment. Tracking entire lineages of cells from the progenitor cell onward reveals that c-di-GMP levels can exhibit increases but also undergo oscillations that can propagate across 10 to 20 generations, thereby encoding more complex instructions for community behavior. Principal component and factor analysis of lineage c-di-GMP data shows that surface commitment behavior correlates with three statistically independent composite features, which roughly correspond to mean c-di-GMP levels, c-di-GMP oscillation period, and surface motility. Surface commitment in young biofilms does not correlate to c-di-GMP increases alone but also to the emergence of high-frequency and small-amplitude modulation of elevated c-di-GMP signal along a lineage of cells. Using this framework, we dissect how increasing or decreasing signal transduction from wild-type levels, by varying the interaction strength between PilO, a component of a principal surface sensing appendage system, and SadC, a key hub diguanylate cyclase that synthesizes c-di-GMP, impacts frequency and amplitude modulation of c-di-GMP signals and cooperative surface commitment."

Bacteria build communities using chemical signals comparable to radio waves | UCLA

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