Characterization of starvation-induced dispersion in Pseudomonas putida biofilms.
The biofilm lifestyle, where microbial cells are aggregated because of expression of cell-to-cell interconnecting compounds, is believed to be of paramount importance to microbes in the environment. Because microbes must be able to alternate between sessile and planktonic states, it is anticipated that they must be able to regulate their ability to form biofilm and to dissolve biofilm. We present an investigation of a biofilm dissolution process occurring in flow-chamber-grown Pseudomonas putida biofilms. Local starvation-induced biofilm dissolution appears to be an integrated part of P. putida biofilm development that causes characteristic structural rearrangements. Rapid global dissolution of entire P. putida biofilms was shown to occur in response to carbon starvation. Genetic analysis suggested that the adjacent P. putida genes PP0164 and PP0165 play a role in P. putida biofilm formation and dissolution. PP0164 encodes a putative periplasmic protein of previously unknown function, and PP0164 mutant bacteria are sticky, and unable to reduce their adhesiveness and dissolve their biofilm in response to carbon starvation. PP0165 encodes a putative transmembrane protein containing GGDEF and EAL domains, and PP0165 mutant bacteria are unable to increase their adhesiveness and form biofilm. We suggest that the PP0164 and PP0165 proteins are involved in the regulation of the adhesiveness of the bacteria; the PP0165 protein through c-di-GMP signalling, and the PP0164 protein as a transducer of the signal.
Gjermansen
Morten
M
Molecular Microbial Ecology Group, BioCentrum-DTU, Building 301. The Technical University of Denmark, DK-2800 Lyngby, Denmark.
Ragas
Paula
P
Sternberg
Claus
C
Molin
Søren
S
Tolker-Nielsen
Tim
T
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D002244:Carbon / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D016958:Pseudomonas putida / Q000737:chemistry / Q000502:physiology*; D013217:Starvation / Q000378:metabolism*
D001426:Bacterial Proteins; D002244:Carbon