title: The role of rpoS on the survival of a p-nitrophenol degrading Pseudomonas putida strain in planktonic and biofilm phases.
abstract: The survival of and interactions between a Pseudomonas putida strain labelled with a red fluorescent protein gene (WT-rfp) and its green fluorescent protein gene-labelled rpoS(-) mutant (KO-gfp) were examined. The generation times of the planktonic WT-rfp and KO-gfp in trypticase soy broth were not significantly different (i.e., p > 0.05) from each other at 30 degrees C. However, the biovolume of the KO-gfp biofilm was about 7 times larger than its WT-rfp counterpart after 48 h of growth. Furthermore, the presence of WT-rfp suppressed the biofilm development of KO-gfp significantly in co-culture biofilms. In planktonic conditions, the pre-carbon-starved WT-rfp achieved a 3-fold greater survival than the pre-carbon-starved KO-gfp in 0.85% saline after a 13-day incubation. In a 1:1 ratio co-culture, the pre-carbon-starved WT-rfp outcompeted the pre-carbon-starved KO-gfp by 20-fold. However, the survival of WT-rfp and KO-gfp were not significantly different from each other in biofilm conditions. Additionally, 11.4% and 61.2% of the WT-rfp and KO-gfp biofilms, respectively, remained intact after washing in 0.2% SDS for 60 min. In conclusion, the rpoS had a significant impact on survival and competitiveness of planktonic P. putida, and on biofilm development, being implicated in competitive suppression of biofilm development in co-culture biofilms and decreased biofilm cohesiveness.
authors: Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada.
authors: M L
authors: ML
authors: Maki
authors: J R
authors: JR
authors: Lawrence
authors: G D W
authors: GD
authors: Swerhone
authors: K T
authors: KT
authors: Leung
mesh_terms: D001422:Bacterial Adhesion / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000254:growth & development; D002244:Carbon / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D017753:Ecosystem; D017353:Gene Deletion; D005798:Genes, Bacterial; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009596:Nitrophenols / Q000378:metabolism*; D010933:Plankton / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D010957:Plasmids / Q000235:genetics; D016958:Pseudomonas putida / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*; D000097573:Red Fluorescent Protein
chemical_list: D001426:Bacterial Proteins; D002244:Carbon; D017931:DNA Primers; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D009596:Nitrophenols; D011994:Recombinant Proteins; D012808:Sigma Factor; D000097573:Red Fluorescent Protein; C069567:sigma factor KatF protein, Bacteria; C024836:4-nitrophenol