When the swimming gets tough, the tough form a biofilm

作者：Belas Robert^*

来源：Molecular Microbiology, 2013, 90(1): 1-5.

DOI：10.1111/mmi.12354

Bacteria live either as independent planktonic cells or as members of surface-attached communities called biofilms. Motility and biofilm development are mutually exclusive events, and control of the phase of this swim-or-stick%26apos; switch involves the ability of the bacterium to sense and respond appropriately to a surface. Cairns etal. (2013) report that the Bacillus subtilis flagellum functions in surface-sensing. Using mutants of B.subtilis that prevent flagellum rotation, they measured the expression and activity of DegU, the response regulator of the two-component DegS-DegU circuit. DegU activity and degU transcription increased when flagellum rotation was prevented, and were dependent on the DegS kinase. Inhibiting flagellar rotation by overexpressing the EpsE flagellar clutch%26apos; or addition of anti-flagellin antiserum also increased degU transcription and activity. These results suggest B.subtilis senses restriction of flagellum rotation as the cell nears a surface. Inhibition of the flagellum activates the DegS-DegU circuit to turn on biofilm formation, i.e. the flagellum is acting as a mechanosensor of surfaces. B.subtilis joins an ever-expanding group of bacteria, including species of Vibrio, Proteus and Caulobacter that use the flagellum as a surface sensor.

• 出版日期2013-10