A5079156406- Bacterial biofilms and quorum sensing
- Microbial Community Ecology and Physiology
- Vibrio bacteria research studies
- Marine Biology and Environmental Chemistry
- Bacterial Genetics and Biotechnology
- Marine Biology and Ecology Research
- Genomics and Phylogenetic Studies
- Bacteriophages and microbial interactions
- Marine and coastal plant biology
- Antibiotic Resistance in Bacteria
- Aquaculture disease management and microbiota
- Antimicrobial Peptides and Activities
- Microbial Fuel Cells and Bioremediation
- Marine Bivalve and Aquaculture Studies
- Marine Sponges and Natural Products
- Wastewater Treatment and Nitrogen Removal
- Water Treatment and Disinfection
- Oral microbiology and periodontitis research
- Membrane Separation Technologies
- Electrochemical sensors and biosensors
- Legionella and Acanthamoeba research
- Gut microbiota and health
- Microbial Natural Products and Biosynthesis
- Marine Ecology and Invasive Species
- Lipid Membrane Structure and Behavior
Singapore Centre for Environmental Life Sciences Engineering
2016-2025
Nanyang Technological University
2016-2025
UNSW Sydney
2016-2025
Environmental Earth Sciences
2019-2025
Google (United States)
2017
Sydney Institute of Marine Science
2011-2016
Singapore University of Social Sciences
2014
J. Craig Venter Institute
2009
Technical University of Denmark
1996-2008
University of Tasmania
2006
Summary Pseudomonas aeruginosa produces extracellular DNA which functions as a cell‐to‐cell interconnecting matrix component in biofilms. Comparison of and chromosomal by the use polymerase chain reaction Southern analysis suggested that is similar to whole‐genome DNA. Evidence P. biofilms cultures generated via lysis subpopulation bacteria was obtained through experiments where β‐galactosidase released from lacZ ‐containing strains assessed. Experiments with wild type lasIrhlI , pqsA pqsL...
Novel molecular tools have been constructed which allow for in situ detection of N-acyl homoserine lactone (AHL)-mediated quorum sensing Pseudomonas aeruginosa biofilms. The reporter responds to AHL activation LasR by expression an unstable version the green-fluorescent protein (Gfp). Gfp-based technology has applied non-destructive, single-cell-level laboratory-based P. It is reported that a synthetic halogenated furanone compound, derivative secondary metabolites produced Australian...
The principles underlying the assembly and structure of complex microbial communities are an issue long-standing concern to field ecology. We previously analyzed community membership bacterial associated with green macroalga Ulva australis , proposed a competitive lottery model for colonization algal surface in attempt explain surprising lack similarity species composition across different samples. Here we extend previous study by investigating link between function these communities, using...
Acylated homoserine lactones (AHLs) play a widespread role in intercellular communication among bacteria. The Australian macroalga Delisea pulchra produces secondary metabolites which have structural similarities to AHL molecules. We report here that these inhibited AHL-controlled processes prokaryotes. Our results suggest the interaction between higher organisms and their surface-associated bacteria may be mediated by interference with bacterial regulatory systems.
ABSTRACT Bacterial biofilms at times undergo regulated and coordinated dispersal events where sessile biofilm cells convert to free-swimming, planktonic bacteria. In the opportunistic pathogen Pseudomonas aeruginosa , we previously observed that occurs concurrently with three interrelated processes within mature biofilms: (i) production of oxidative or nitrosative stress-inducing molecules inside structures, (ii) bacteriophage induction, (iii) cell lysis. Here examine whether specific...
Many marine bacteria have evolved to grow optimally at either high (copiotrophic) or low (oligotrophic) nutrient concentrations, enabling different species colonize distinct trophic habitats in the oceans. Here, we compare genome sequences of two bacteria, Photobacterium angustum S14 and Sphingopyxis alaskensis RB2256, that serve as useful model organisms for copiotrophic oligotrophic modes life specifically relate genomic features strategy these define their molecular mechanisms adaptation....
Most biofilms in their natural environments are likely to consist of consortia species that influence each other synergistic and antagonistic manners. However, few reports specifically address interactions within multispecies biofilms. In this study, 17 epiphytic bacterial strains, isolated from the surface marine alga Ulva australis, were screened for when present together different combinations. Four isolates, Microbacterium phyllosphaerae, Shewanella japonica, Dokdonia donghaensis,...
Summary: Acylated homoserine lactone (AHL)-mediated gene expression controls phenotypes involved in colonization, often specifically of higher organisms, both marine and terrestrial environments. The red alga Delisea pulchra produces halogenated furanones which resemble AHLs structurally show inhibitory activity at ecologically realistic concentrations AHL bioassays. Evidence is presented that displace tritiated OHHL [N-3- (oxohexanoy1)-L-homoserine lactone] from Escherichia coli cells...
N-acyl-L-homoserine lactones (AHLs) are co-regulatory ligands required for control of the expression genes encoding virulence traits in many Gram-negative bacterial species. Recent studies have indicated that AHLs modulate cellular concentrations LuxR-type regulatory proteins by binding and fortifying these against proteolytic degradation (Zhu & Winans, 2001 R43 ). Halogenated furanones produced macroalga Delisea pulchra inhibit AHL-dependent gene expression. This study assayed an vivo...
Several characteristics of the 16S rRNA gene, such as its essential function, ubiquity, and evolutionary properties, have allowed it to become most commonly used molecular marker in microbial ecology. However, one fact that has been overlooked is multiple copies this gene are often present a given bacterium. These intragenomic can differ sequence, leading identification ribotypes for single organism. To evaluate impact heterogeneity on performance marker, we compared phylogenetic those...
Bacteria growing in biofilms often develop multicellular, three-dimensional structures known as microcolonies. Complex differentiation within of Pseudomonas aeruginosa occurs, leading to the creation voids inside microcolonies and dispersal cells from these voids. However, key developmental processes regulating events are poorly understood. A normal component multicellular development is cell death. Here we report that a repeatable pattern death lysis occurs P. during course development....
The newly established genus Pseudoalteromonas contains numerous marine species which synthesize biologically active molecules. production of a range compounds are against variety target organisms appears to be unique characteristic for this and may greatly benefit cells in their competition nutrients colonization surfaces. Species generally found association with eukaryotes display anti-bacterial, bacteriolytic, agarolytic algicidal activities. Moreover, several isolates specifically prevent...
In cell‐free Pseudomonas aeruginosa culture supernatants, we identified two compounds capable of activating an N ‐acylhomoserine lactone (AHL) biosensor. Mass spectrometry and NMR spectroscopy revealed that these were not AHLs but the diketopiperazines (DKPs), cyclo(ΔAla‐ l ‐Val) cyclo( ‐Pro‐ ‐Tyr) respectively. These also found in supernatants from Proteus mirabilis , Citrobacter freundii Enterobacter agglomerans [cyclo(ΔAla‐ only]. Although both DKPs absent fluorescens alcaligenes...
ABSTRACT Bacteria in biofilms often undergo active dispersal events and revert to a free-swimming, planktonic state complete the biofilm life cycle. The signaling molecule nitric oxide (NO) was previously found trigger opportunistic pathogen Pseudomonas aeruginosa at low, nontoxic concentrations (N. Barraud, D. J. Hassett, S. H. Hwang, A. Rice, Kjelleberg, Webb, Bacteriol. 188:7344-7353, 2006). NO further shown increase cell motility susceptibility antimicrobials. Recently, numerous studies...
Contemporary microbial community analysis frequently involves PCR-amplified sequences of the 16S rRNA gene (rDNA). However, this technology carries inherent problem heterogeneity between copies rDNA in many species. As an alternative to analysis, we employed for RNA polymerase beta subunit (rpoB), which appears exist one copy only bacteria. In present study, frequency bacteria isolated from marine environment was assessed using bacterial isolates red alga Delisea pulchra and surface a rock....
Microorganisms often form symbiotic relationships with eukaryotes, and the complexity of these can range from those one single dominant symbiont to associations hundreds species. Microbial symbionts occupying equivalent niches in different eukaryotic hosts may share functional aspects, convergent genome evolution has been reported for simple systems insects. However, complex communities, it is largely unknown how prevalent equivalence whether functions are conducted by evolutionarily...