Project description:To elucidate the impact of the carriage of carbazole-degradative plasmid pCAR1 on biofilm formation by host bacteria, we compared biofilm morphology of pCAR1-free and pCAR1-carrying three Pseudomonas hosts: P. putida KT2440, P. aeruginosa PAO1 and P. fluorescens Pf0-1 using confocal laser scanning microscopy. Although pCAR1 carriage had no significant influence on biofilm formed by PAO1 and Pf0-1, pCAR1-carrying KT2440 became filamentous and formed flat biofilm, whereas pCAR1-free KT2440 formed mushroom-like biofilm. pCAR1 carries three genes encoding nucleoid-associated proteins (NAPs); Pmr, Pnd, and Phu. Because intensive filamentous morphology was observed in two double mutants (DpmrDpnd and DpmrDphu), these NAPs cooperatively suppress cell filamentation and flat biofilm formation in KT2440(pCAR1) cells. Based on the results of transcriptome analyses of these double mutants, we could find 32 candidate genes which may be involved in the filamentation of KT2440(pCAR1). Overproduction in KT2440 and KT2440(pCAR1) of three of candidate genes (PP_2193, PP_0308, or PP_0309) induced temporal filamentation of the cells, suggesting that pCAR1 induced the abnormal filamentous morphology of KT2440 cells by overexpression of plural genes including PP_2193, PP_0308, and PP_0309. In addition, pCAR1-borne NAPs suppress the morphological changes probably by decreasing the transcriptome change by pCAR1 carriage. The pCAR1 carriage impact of chromosomal RNA maps in biofilm formation.
Project description:The aim of this experiment is to ascertain which genes have their expression influenced by PG1432. PG1432 encodes a putative sensor histidine kinase which is part of two component signal transduction that was highly up-regulated in P. gingivalis mature biofilm cells. PG1432 was disrupted in P. gingivalis W50 by insertion of ermF cassette. The strain W50 PG1432 mutant was designated ECR222. Two independent replicates of each strain were grown for 30 days in continuous culture in chemostats using brain heart infusion media supplemented with 0.5 mg mL-1 cysteine and 5 �~A�g mL-1 hemin. Although strain W50 formed sufficient biofilm to use for total RNA harvest and microarray analysis, strain ERC222 formed only sparse biofilm showing that disruption of PG1432 impaired biofilm formation by this mutant. We were unable to collect sufficient biofilm cells of strain ECR222 therefore the microarray analysis total RNAs were harvested only from planktonic phase cells. The transcriptome of the mutant ECR222 were compared to that of strain W50.
Project description:To elucidate the impact of the carriage of carbazole-degradative plasmid pCAR1 on biofilm formation by host bacteria, we compared biofilm morphology of pCAR1-free and pCAR1-carrying three Pseudomonas hosts: P. putida KT2440, P. aeruginosa PAO1 and P. fluorescens Pf0-1 using confocal laser scanning microscopy. Although pCAR1 carriage had no significant influence on biofilm formed by PAO1 and Pf0-1, pCAR1-carrying KT2440 became filamentous and formed flat biofilm, whereas pCAR1-free KT2440 formed mushroom-like biofilm. pCAR1 carries three genes encoding nucleoid-associated proteins (NAPs); Pmr, Pnd, and Phu. Because intensive filamentous morphology was observed in two double mutants (DpmrDpnd and DpmrDphu), these NAPs cooperatively suppress cell filamentation and flat biofilm formation in KT2440(pCAR1) cells. Based on the results of transcriptome analyses of these double mutants, we could find 32 candidate genes which may be involved in the filamentation of KT2440(pCAR1). Overproduction in KT2440 and KT2440(pCAR1) of three of candidate genes (PP_2193, PP_0308, or PP_0309) induced temporal filamentation of the cells, suggesting that pCAR1 induced the abnormal filamentous morphology of KT2440 cells by overexpression of plural genes including PP_2193, PP_0308, and PP_0309. In addition, pCAR1-borne NAPs suppress the morphological changes probably by decreasing the transcriptome change by pCAR1 carriage.
2014-05-08 | GSE56856 | GEO
Project description:Biofilm formation on eight polymer material surfaces
Project description:The aim of the present study was to investigate the mechanisms by which fosfomycin restrains biofilm formation and affects a 24h-old biofilm of S. aureus. RNA sequencing (RNA-Seq) technology was used to compare the transcriptomes of S. aureus biofilms formed or treated with sublethal concentrations of fosfomycin.
Project description:Immobilization of Clostridium acetobutylicum B3 onto fibrous matrix by surface-adsorption was developed and applied to biobutanol production. The immobilized C. acetobutylicum B3 cells formed biofilm and showed dramatically improved butanol tolerance and production rate. DNA array-based transcriptional analysis of C.acetobutylicum B3 biofilm cells was conducted to elucidate the gene expression profile of the biofilm cells. Results showed that about 16% of the whole genome was differentially expressed. The most apparently differentially expressed genes were involved in amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, and coenzyme transport and metabolism. Samples for biofilm cells and planktonic cells were withdrawn at four diffierent fermentation phases. The gene expression pattern of biofilm cells were investigated relative to that of planktonic cells from the same phase. The experiment was carried out twice independently. Cotton fibrous matrix (60 g/L) was used as biofilm carrier.
Project description:Immobilization of Clostridium acetobutylicum B3 onto fibrous matrix by surface-adsorption was developed and applied to biobutanol production. The immobilized C. acetobutylicum B3 cells formed biofilm and showed dramatically improved butanol tolerance and production rate. DNA array-based transcriptional analysis of C.acetobutylicum B3 biofilm cells was conducted to elucidate the gene expression profile of the biofilm cells. Results showed that about 16% of the whole genome was differentially expressed. The most apparently differentially expressed genes were involved in amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, and coenzyme transport and metabolism. Samples for biofilm cells and planktonic cells were withdrawn at four diffierent fermentation phases. The gene expression pattern of biofilm cells were investigated relative to that of planktonic cells from the same phase. The experiment was carried out twice independently. Cotton fibrous matrix (60 g/L) was used as biofilm carrier.
Project description:Two lineages of enterohemorrhagic (EHEC) Escherichia coli O157:H7 (EDL933, Stx1+ and Stx2+) and 86-24 (Stx2+) were investigated in regards to biofilm formation on an abiotic surface. Strikingly, EDL933 strain formed a robust biofilm while 86-24 strain formed no biofilm on either a polystyrene plate or a polyethylene tube. To identify the genetic mechanisms of different biofilm formation in two EHEC strains, DNA microarrays were first performed and phenotypic assays were followed. In the comparison of the EDL933 strain versus 86-24 strain, genes (csgBAC and csgDEFG) involved in curli biosynthesis were significantly induced while genes (trpLEDCB and mtr) involved in indole signaling were repressed. Additionally, a dozen of phage genes were differentially present between two strains. Curli assays using a Congo red plate and scanning electron microscopy corroborate the microarray data as the EDL 933 strain produces a large amount of curli, while 86-24 forms much less curli. Also, the indole production in the EDL933 was 2-times lower than that of 86-24. It was known that curli formation positively regulates and indole negatively regulates biofilm formation of EHEC. Hence, it appears that less curli formation and high indole production in the 86-24 strain are majorly responsible for no biofilm formation.