The biocontrol strain Pseudomonas fluorescens F113 produces the Rhizobium small bacteriocin, N-(3-hydroxy-7-cis-tetradecenoyl)homoserine lactone, via HdtS, a putative novel N-acylhomoserine lactone synthase

Article Abstract:

The biocontrol strain Pseudomonas fluorescens F113 has been found to produce the Rhizobium small bacteriocin, N-(3-hydroxy-7-cis-tetradecenoyl)homoserine lactone. It does so via HdtS, a putative novel N-acylhomoserine lactone synthase. Hdts is not in either of the known AHL synthase families and may be a member of a third protein family able to biosynthesize acylhomoserine lactones (AHLs). P. fluorescence F113 was cross-streaked against AHL biosensors able to detect short or long acyl chain AHLs. N-acylhomoserine lactones are quorum-sensing signal molecules and part of cell-density-dependent control of secondary metabolite and virulence gene expression. A gene, hdtS, was cloned and sequenced.

United Kingdom, Ireland, Causes of, Genetic aspects, Rhizobium, Cell interaction, Cell interactions, Transferases, Population genetics, Pseudomonas fluorescens, Lactones, Rhizoids, Cellular recognition

---

Activation of Pseudomonas aeruginosa elastase in Pseudomonas putida by triggering dissociation of the propeptide-enzyme complex

Article Abstract:

Pseudomonas aeruginosa elastase has been found to be activated in Pseudomonas putida when dissociation of the propeptide-enzyme complex is triggered. The proenzyme normally processed in P. putida has been shown to be not actively secreted by the Xcp mechanism. Substantial amounts of the enzyme were detected in the extracellular medium, however. These and other findings led to the conclusion that Ala-15 and Thr-153 are necessary for the inhibitor function, but not for the chaperone function of the propeptide.

Netherlands, Pseudomonas putida, Pseudomonas aeruginosa, Protein folding, Protein research, Bacterial proteins

---

Cell density-regulated recovery of starved biofilm populations of ammonia-oxidizing bacteria

Article Abstract:

The speed of recovery of cell suspensions and biofilm populations of the ammonia oxidizer Nitrosomonas europaea after starvation was investigated. After resupply of ammonium, starved biofilms had no lag phase before nitrite production, even after starvation for 43.2 days, although there were indications of cell loss during starvation. Findings indicated that fast recovery of high-density biofilm populations may be caused by production and accumulation of N-(3-oxohexanoyl)-L-homoserine lactone to levels not possible in relatively low-density cell suspensions.

Microbial populations

Similar abstracts:

• Abstracts: Polychlorinated biphenyl rhizoremediation by Pseudomonas fluorescens F113 derivatives, using a Sinorhizobium melitoti nod system to drive bhp gene expression
• Abstracts: Characterization of Pseudomonas aeruginosa bacteriophage UNL-1, a bacterial virus with a novel UV-A-inducible DNA damage reactivation phenotype
• Abstracts: The Sesbania root symbionts Sinorhizobium saheli and S. teranga bv. sesbaniae can form stem nodules on Sesbania rostrata, although they are less adapted to stem nodulation than Azorhizobium caulinodans
• Abstracts: Homoduplex and heteroduplex polymorphisms of the amplified ribosomal 16S-23S internal transcribed spacers describe genetic relationships in the "Bacillus cereus group"
• Abstracts: Detection of N-acylhomoserine lactones in lung tissues of mice infected with Pseudomonas aeruginosa. Quantification of biofilm structures by the novel computer program COMSTAT

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.