A5077489422- Microbial Community Ecology and Physiology
- Bacterial biofilms and quorum sensing
- Bacterial Genetics and Biotechnology
- Microbial bioremediation and biosurfactants
- Microbial Metabolic Engineering and Bioproduction
- Microbial Fuel Cells and Bioremediation
- Photosynthetic Processes and Mechanisms
- Genomics and Phylogenetic Studies
- Algal biology and biofuel production
- Metalloenzymes and iron-sulfur proteins
- Vibrio bacteria research studies
- Enzyme Structure and Function
- Protist diversity and phylogeny
- Photoreceptor and optogenetics research
- Amino Acid Enzymes and Metabolism
- Cystic Fibrosis Research Advances
- Wastewater Treatment and Nitrogen Removal
- Legume Nitrogen Fixing Symbiosis
- Plant Pathogenic Bacteria Studies
- Biofuel production and bioconversion
- Antibiotic Resistance in Bacteria
- Biochemical and biochemical processes
- Ammonia Synthesis and Nitrogen Reduction
- Metabolomics and Mass Spectrometry Studies
- Cassava research and cyanide
University of Washington
2016-2025
Seattle University
2008-2021
Qingdao Agricultural University
2020
South China Agricultural University
2017
University of New Orleans
2011
University of Toronto
2011
TH Bingen University of Applied Sciences
2011
Max Planck Society
2011
University of Iowa
1997-2006
University of British Columbia
2006
Pseudomonas aeruginosa causes chronic biofilm infections, and its ability to attach surfaces other cells is important for formation maintenance. Mutations in a gene called wspF , part of putative chemosensory signal-transduction operon, have been shown result cell aggregation altered colony morphology. The WspF phenotypes depend on the presence WspR, which member family signal transduction proteins known as response regulators. It likely that effect mutation cause constitutive activation...
Rhodopseudomonas palustris is among the most metabolically versatile bacteria known. It uses light, inorganic compounds, or organic for energy. acquires carbon from many types of green plant–derived compounds by dioxide fixation, and it fixes nitrogen. Here we describe genome sequence R. palustris, which consists a 5,459,213-base-pair (bp) circular chromosome with 4,836 predicted genes plasmid 8,427 bp. The reveals that confer remarkably large number options within given type metabolism,...
Summary High levels of the intracellular signalling molecule cyclic diguanylate (c‐di‐GMP) supress motility and activate exopolysaccharide (EPS) production in a variety bacterial species. In many bacteria part effect c‐di‐GMP is on gene expression, but mechanism involved not known for any We have identified protein FleQ as c‐di‐GMP‐responsive transcriptional regulator Pseudomonas aeruginosa . to expression flagella biosynthesis genes. Here we show that it also represses transcription genes...
Pseudomonas aeruginosa is recognized for its ability to colonize diverse habitats, ranging from soil immunocompromised people. The formation of surface-associated communities called biofilms one factor thought enhance colonization and persistence in these environments. Another the P. diversify genetically, generating phenotypically distinct subpopulations. One manifestation diversification appearance colony morphology variants on solid medium. Both laboratory biofilm growth chronic cystic...
The Calvin-Benson-Bassham cycle (Calvin cycle) catalyzes virtually all primary productivity on Earth and is the major sink for atmospheric CO 2 . A less appreciated function of fixation as an electron-accepting process. It known that anoxygenic phototrophic bacteria require Calvin to accept electrons when growing with light their sole energy source organic substrates carbon source. However, it was unclear why what extent required are more oxidized than biomass. To address these questions we...
Bacteria have a tendency to attach surfaces and grow as structured communities called biofilms. Chronic biofilm infections are problem because they tend resist antibiotic treatment difficult eradicate. Bacterial biofilms an extracellular matrix that is usually composed of mixture polysaccharides, proteins, nucleic acids. This has long been assumed play passive structural protective role for resident cells. Here we show this view oversimplification the can active in stimulating its own...
Bis-(3′–5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) modulates the transition between planktonic and biofilm life styles. In response to c-di-GMP, enhancer binding protein FleQ from Pseudomonas aeruginosa derepresses expression of Pel exopolysaccharide genes required for formation when a second protein, FleN is present. A model that c-di-GMP induces its dissociation pelA promoter allowing RNA polymerase access this site. To test this, we analyzed DNA footprinting patterns with...
The second messenger signaling molecule cyclic diguanylate monophosphate (c-di-GMP) drives the transition between planktonic and biofilm growth in many bacterial species. Pseudomonas aeruginosa has two surface sensing systems that produce c-di-GMP response to adherence. Current thinking field is once cells attach a surface, they uniformly respond by producing c-di-GMP. Here, we describe how Wsp system generates heterogeneity sensing, resulting physiologically distinct subpopulations of...
In Escherichia coli and some other gamma-Proteobacteria, the alternative sigma factor RpoS functions as a regulator of general stress response. The role in Pseudomonas aeruginosa is not clear. Although P. contributes to resistance several environmental stresses, its appears be less pivotal than E. coli. aeruginosa, also regulates production virulence factors influences expression individual genes that are controlled by quorum sensing. Some quorum-controlled induced RpoS, whereas others...
Aromatic compounds are important growth substrates for microorganisms. They form a large group of diverse including lignin monomers, amino acids, quinones, and flavonoids. Aerobic aromatic metabolism is characterized by the extensive use molecular oxygen which essential hydroxylation cleavage ring structures. The anaerobic low mass soluble requires, necessity, quite different strategy. In most known cases, aromaticity broken reduction subsequently opened hydrolytically. A small number...
Summary Pseudomonas aeruginosa in the lungs of cystic fibrosis patients grows to high densities mucopurulent material that is depleted oxygen. Some have concluded growth these circumstances dependent on anaerobic nitrate respiration. Here we present data favour alternative hypothesis microaerobic respiration predominant mode P. lung. We found strain PAO1 and a mucoid derivative each grew at dissolved oxygen concentrations less than 3 μM. This lower concentration has been measured hypoxic...
ABSTRACT The bioremediation of polluted groundwater and toxic waste sites requires that bacteria come into close physical contact with pollutants. This can be accomplished by chemotaxis. Five motile strains use five different pathways to degrade toluene were tested for their ability detect swim towards this pollutant. Three the ( Pseudomonas putida F1, Ralstonia pickettii PKO1, Burkholderia cepacia G4) attracted toluene. In each case, response was dependent on induction growth mendocina KR1...
The Pseudomonas aeruginosa Wsp signal transduction system produces cyclic-di-GMP (c-di-GMP), an intracellular messenger that stimulates biofilm formation and suppresses motility. is homologous to chemotaxis systems includes a membrane-bound receptor protein, WspA, response regulator GGDEF WspR, catalyses c-di-GMP synthesis when phosphorylated. We found the subcellular distributions of fluorescent protein-tagged WspA WspR differed markedly from their counterparts. WspA-YFP formed patches in...
The purple nonsulfur photosynthetic bacterium Rhodopseudomonas palustris used diverse aromatic compounds for growth under anaerobic and aerobic conditions. Many phenolic, dihydroxylated, methoxylated acids, as well aldehydes hydroaromatic supported of strain CGA001 in both the presence absence oxygen. Some were metabolized only or Two other strains, CGC023 CGD052, had similar substrate utilization patterns, but CGD052 was able to use a slightly larger number growth. These results show that...
Pseudomonas putida PRS2000 is chemotactic to 4-hydroxybenzoate and other aromatic acids. This behavioral response induced when cells are grown on or benzoate, compounds that degraded via the beta-ketoadipate pathway. Isolation of a transposon mutant defective in chemotaxis allowed identification new gene cluster designated pcaRKF. DNA sequencing, mutational analysis, complementation studies revealed pcaR encodes regulatory protein required for induction at least four enzymes pathway pcaF...
Two naphthalene-degrading bacteria, Pseudomonas putida G7 and sp. strain NCIB 9816-4, were chemotactically attracted to naphthalene in drop assays modified capillary assays. Growth on or salicylate induced the chemotactic response. P. was also biphenyl; other polyaromatic hydrocarbons that tested did not appear be chemoattractants for either strain. Strains cured of degradation plasmid naphthalene.
The first step in the anaerobic pathway of benzoate degradation by Rhodopseudomonas palustris is catalyzed benzoate-coenzyme A ligase. To study factors influencing synthesis this enzyme, a polyclonal antiserum was prepared and immunoblot assays. Benzoate-CoA ligase synthesized when cells were grown with benzoate, as well hydroxyl- methyl-substituted benzoates. Partially reduced alicyclic compounds proposed to be intermediates also induced benzoate-CoA Ligase repressed oxygen. diversity...
Significance Many bacteria respond to environmental cues by producing cyclic diguanosine monophosphate (c-di-GMP), which binds proteins modulate transitions between sessile and motile lifestyles important for chronic acute infections, respectively. The breadth of protein targets mechanisms action c-di-GMP remain unknown. In the opportunistic pathogen Pseudomonas aeruginosa , FleQ, a transcription factor that is master regulator flagella synthesis member large family AAA+ ATPase proteins. We...
The photosynthetic bacterium Rhodopseudomonas palustris is one of just a few prokaryotes described so far that has vnf and anf genes for alternative vanadium cofactor (V) iron (Fe) nitrogenases in addition to nif molybdenum (Mo) nitrogenase. Transcriptome data indicated the 32 gene cluster, but not or genes, were induced wild-type Mo nitrogenase-expressing strains grown under nitrogen-fixing conditions Mo-containing medium. Strains unable express functional nitrogenase due mutations...
In chronic infections, pathogens are often in the presence of other microbial species. For example, Pseudomonas aeruginosa is a common and detrimental lung pathogen individuals with cystic fibrosis (CF) co-infections Candida albicans common. Here, we show that P. biofilm formation phenazine production were strongly influenced by ethanol produced fungus C. albicans. Ethanol stimulated phenotypes indicative increased levels cyclic-di-GMP (c-di-GMP), c-di-GMP 2-fold higher ethanol. Through...