Table 1.
Cues, signals and environmental factors linked to dispersion.
| Cues, signals and factors | Species | Effector regulatory system | Source |
|---|---|---|---|
| Fatty acid signaling (DSF and BDSF) | Xanthomonas campestris | DSF and Rpf genes positively control the synthesis of manA-encoded endo-β-1,4-mannanase, which degrades the matrix; DSF negatively affects the expression of xagABC encoding a glycosyl transferase system Induction of low c-di-GMP levels | |
| Fatty acid signaling (cis-DA) | Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Bacillus subtilis, Proteus mirabilis, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans | Similar to DSF and BDSF, cis-DA may induce low c-di-GMP levels, [Au: is this entry specific for Pseudomonas aeruginosa etc? yes, specific for P. aeruginosa but could also be for other strains but has not been explored] | Correct reference is Davies and Marques, 2009, Ref #5964,109,164 |
| Oxygen depletion | P. aeruginosa | Dispersion response is dependent on PDE RbdA, probably to induce low c-di-GMP levels | 165 |
| Starvation due to cessation of flowing conditions (oxygen or nutrients) | Shewanella oneidensis | Dispersion-inducing conditions are linked to mxdB encoding a putative membrane-associated glycosyl transferase and the probable induction of a PDE to reduce c-di-GMP levels | 48 |
| Pseudomonas putida, P. aeruginosa, P. fluorescens | Dispersion-inducing conditions have been linked to low c-di-GMP levels and the release of the adhesin LapA in biofilms by P. putida and P. fluorescens. Additionally, reports suggest lack of nutrients and cell lysis but not the the accumulation of a metabolic product to be contribute to the dispersion response | 66–69 | |
| S. aureus | Quorum sensing, Agr-dependent | 134 | |
| Nutrient availability (glucose, glutamate, succinate and citrate) | P. aeruginosa | Dispersion in response to nutrients is dependent on phosphorylation events, and coincides with a decrease in c-di-GMP and increased PDE activity Factors identified to have a role include BdlA, PDEs DipA and RbdA, and DGCs NicD and GcbA Induction of matrix-degrading enzymes include endonucleases EndA and EddA, and glycosyl hydrolases PelA and PslG | 87,93,95,107,115,116,166,167 |
| Acinetobacter sp, S. pneumoniae | Dispersion response is linked to quorum sensing/Interkingdom signaling | 168 | |
| Serratia marcescens | dispersion is linked to quorum sensing | 169 | |
| Nitric oxide | P. aeruginosa | Dispersion in response to nitric oxide coincides with a decrease in c-di-GMP and increased PDE activity Factors identified to have a role include BdlA, PDEs NbdA, MucR, DipA and RbdA Induction of matrix-degrading enzymes include endonucleases EndA and EddB, and glycosyl hydrolases PelA and PslG | 97,98,115,116,170 |
| Nitrosomonas europaea Ammonia oxidizer | no effector proteins have been identified | 171 | |
| Iron | P. aeruginosa | Exposure to elevated iron concentrations repress the expression of certain genes essential for scavenging iron, with scavenging and acquisition of iron being essential for biofilm formation by P. aeruginosa. | 79,172 |
| Reduction of c-di-GMP | P. aeruginosa | Dispersion induced by overexpression of the response regulator RcsB which leads to induction of the PDE PvrR | 173,68 |
| P. putida | Dispersion induced by overexpression of E. coli-derived PDE YhjH, which might lead to LapG-dependent release of LapA | 94 |
PDE, phosphodiesterase; DGC, diguanylate cyclase, cis-DA, cis-2 decenoic acid; DSF, cis-11-methyl-2-dodecenoic acid; BDSF, cis-2-dodecenoic acid; c-di-GMP, bis-(3’-5’)-cyclic dimeric guanosine monophosphate; DGCs, diguanylate cyclases.