Abstract
The phytopathogenic bacterium Pectobacterium atrosepticum (Pba) strain SCRI1043 does not exhibit appreciable biofilm formation under standard laboratory conditions. Here we show that a biofilm-forming phenotype in this strain could be activated from a cryptic state by increasing intracellular levels of c-di-GMP, through overexpression of a constitutively active diguanylate cyclase (PleD*) from Caulobacter crescentus. Randomly obtained Pba transposon mutants defective in the pga operon, involved in synthesis and translocation of poly-beta-1,6-N-acetyl-D-glucosamine (PGA), were all impaired in this biofilm formation. The presence of the PGA-degrading enzyme dispersin B in the growth media prevented biofilm formation by Pba overexpressing PleD*, further supporting the importance of PGA for biofilm formation by Pba. Importantly, a pga mutant exhibited a reduction in root binding to the host plant under conditions of high intracellular c-di-GMP levels. A modest but consistent increase in pga transcript levels was associated with high intracellular levels of c-di-GMP. Our results indicate tight control of PGA-dependent biofilm formation by c-di-GMP in Pba.
Original language | English |
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Pages (from-to) | 3340-3348 |
Number of pages | 9 |
Journal | Microbiology |
Volume | 157 |
Issue number | 12 |
DOIs | |
Publication status | Published - Dec 2011 |
Keywords
- CAROTOVORA SUBSP-ATROSEPTICA
- YERSINIA-PESTIS BIOFILM
- CYCLIC DIGUANYLIC ACID
- ESCHERICHIA-COLI
- ERWINIA-CAROTOVORA
- PSEUDOMONAS-AERUGINOSA
- ACTINOBACILLUS-ACTINOMYCETEMCOMITANS
- CELLULOSE SYNTHESIS
- EXOPOLYSACCHARIDE PRODUCTION
- RHIZOBIUM-LEGUMINOSARUM