A5087675596- Genomics and Phylogenetic Studies
- Microbial Community Ecology and Physiology
- Bacterial Genetics and Biotechnology
- Bacteriophages and microbial interactions
- Bacterial biofilms and quorum sensing
- Microfluidic and Bio-sensing Technologies
- Vibrio bacteria research studies
- Gut microbiota and health
- Ginger and Zingiberaceae research
- Nanopore and Nanochannel Transport Studies
- Microfluidic and Capillary Electrophoresis Applications
- RNA and protein synthesis mechanisms
- Biochemical and Structural Characterization
- Methane Hydrates and Related Phenomena
- Legume Nitrogen Fixing Symbiosis
- Piperaceae Chemical and Biological Studies
- Protist diversity and phylogeny
- Photosynthetic Processes and Mechanisms
- Evolution and Genetic Dynamics
- Dietary Effects on Health
- Micro and Nano Robotics
- Geomagnetism and Paleomagnetism Studies
- Plant nutrient uptake and metabolism
- Tea Polyphenols and Effects
- Antimicrobial Peptides and Activities
Université de Montréal
2019-2024
Indiana University Bloomington
2010-2022
Seoul National University
2012
Yale University
2007
Université du Québec à Montréal
2005
Marine Biological Laboratory
2002
Woods Hole Oceanographic Institution
2002
ABSTRACT Microbial communities in hydrothermally active sediments of the Guaymas Basin (Gulf California, Mexico) were studied by using 16S rRNA sequencing and carbon isotopic analysis archaeal bacterial lipids. The harbored uncultured euryarchaeota two distinct phylogenetic lineages within anaerobic methane oxidation 1 (ANME-1) group, ANME-1a ANME-1b, ANME-2c lineage Methanosarcinales , both previously assigned to methanotrophic archaea. lipids included archaeol, diagnostic for...
Elucidating a bacterial sense of touch Bacteria can adhere to surfaces within the host. This leads tissue colonization, induction virulence, and eventually formation biofilms—multicellular communities that resist antibiotics clearance by immune system (see Perspective Hughes Berg). Hug et al. show bacteria have allows them change their behavior rapidly when encountering surfaces. tactile sensing makes use inner components flagellum, rotary motor powered proton motif force facilitates...
Elongation of many rod-shaped bacteria occurs by peptidoglycan synthesis at discrete foci along the sidewall cells. However, within Rhizobiales, there are budding bacteria, in which new cell growth is constrained to a specific region. The phylogeny Rhizobiales indicates that this mode zonal may be ancestral. We demonstrate bacterium Agrobacterium tumefaciens grows unidirectionally from pole generated after division and has an atypical composition. Polar under all conditions tested, including...
Several approaches to manipulate the gut microbiome for improving activity of cancer immune-checkpoint inhibitors (ICI) are currently under evaluation. Here, we show that oral supplementation with polyphenol-rich berry camu-camu (CC; Myrciaria dubia) in mice shifted microbial composition, which translated into antitumor and a stronger anti-PD-1 response. We identified castalagin, an ellagitannin, as active compound CC. Oral administration castalagin enriched bacteria associated efficient...
Molecular microbial ecology studies have revealed remarkable prokaryotic diversity in extreme hydrothermal marine environments. There are no comparable reports of culture-independent surveys eukaryotic life warm, anoxic sediments. By using sequence comparisons PCR-amplified small subunit ribosomal RNAs, we characterized vent environments Guaymas Basin the Gulf California. Many sequences from these sediments and overlaying seawater represent previously uncharacterized protists, including...
The modern age of metagenomics has delivered unprecedented volumes data describing the genetic and metabolic diversity bacterial communities, but it failed to provide information about coincident cellular morphologies. Much like biosynthetic capabilities, morphology comprises a critical component fitness, molded by natural selection into many elaborate shapes observed across domain. In this essay, we discuss its implications for understanding both mechanistic adaptive basis morphogenesis. We...
In natural systems, bacteria form complex, surface-attached communities known as biofilms. This lifestyle presents numerous advantages compared with unattached or planktonic life, such exchange of nutrients, protection from environmental stresses and increased tolerance to biocides. Despite benefits, dispersal also plays an important role in escaping deteriorating environments successfully colonizing favourable, unoccupied habitat patches. The α-proteobacterium Caulobacter crescentus...
In the environment, most bacteria form surface-attached cell communities called biofilms. The attachment of single cells to surfaces involves an initial reversible stage typically mediated by surface structures such as flagella and pili, followed a permanent adhesion usually polysaccharide adhesives. Here, we determine absolute relative timescales frequencies irreversible bacterium Caulobacter crescentus glass in microfluidic device. We used fluorescence microscopy C. expressing green...
Acquisition of foreign DNA by natural transformation is an important mechanism adaptation and evolution in diverse microbial species. Here, we characterize the ComM, a broadly conserved AAA+ protein previously implicated homologous recombination transforming (tDNA) naturally competent Gram-negative bacterial In vivo, found that ComM was required for efficient comigration linked genetic markers Vibrio cholerae Acinetobacter baylyi, which consistent with role branch migration. Also,...
Jakobids are free-living, heterotrophic flagellates that might represent early-diverging mitochondrial protists. They share ultrastructural similarities with eukaryotes occupy basal positions in molecular phylogenies, and their genome architecture is eubacterial-like, suggesting a close affinity the ancestral alpha-proteobacterial symbiont gave rise to mitochondria hydrogenosomes. To elucidate relationships among jakobids other eukaryotic lineages, we characterized alpha- beta-tubulin genes...
Bacteria use surface appendages called type IV pili to perform diverse activities including DNA uptake, twitching motility, and attachment surfaces. The dynamic extension retraction of are often required for these activities, but the stimuli that regulate dynamics remain poorly characterized. To address this question, we study bacterial pathogen Vibrio cholerae, which uses mannose-sensitive hemagglutinin (MSHA) attach surfaces in aquatic environments as first step biofilm formation. Here, a...
Summary Serial analysis of ribosomal sequence tags (SARST) is a novel technique for characterizing microbial community composition. The SARST method captures information from concatemers short 16S rDNA polymerase chain reaction (PCR) amplicons complex populations DNA. Here, we describe similar method, serial V6 (SARST‐V6), which targets the hypervariable region bacterial rRNA genes. SARST‐V6 exploits internal primer sequences to generate compatible restriction digest overhangs, thereby...
Summary Organelles with specialized form and function occur in diverse bacteria. Within the A lphaproteobacteria, several species extrude thin cellular appendages known as stalks, which nutrient uptake, buoyancy reproduction. Consistent their specialization, stalks maintain a unique molecular composition compared cell body, but how this is achieved remains to be fully elucidated. Here we dissect mechanism of localization StpX , stalk‐specific protein C aulobacter crescentus . Using forward...
The Delaware-Maryland-Virginia (DelMarVa) Peninsula, flanking one side of the Chesapeake Bay, is home to a substantial broiler chicken industry. As such, it produces significant amount manure that typically composted and spread onto local croplands as fertilizer. Phytate (myo inositol hexakisphosphate), major form organic phosphorus in manure, can be hydrolysed by microorganisms produce orthophosphate. Orthophosphate eutrophication agent which lead algal blooms, hypoxia fish kills Bay its...
The Alphaproteobacteria comprise morphologically diverse bacteria, including many species of stalked bacteria. Here we announce the genome sequences eight alphaproteobacteria, first belonging to genera Asticcacaulis, Hirschia, Hyphomicrobium, and Rhodomicrobium.
In bacteria and eukaryotes alike, proper cellular physiology relies on robust subcellular organization. For the phototrophic purple nonsulfur (PNSB), this organization entails use of a light-harvesting, membrane-bound compartment known as intracytoplasmic membrane (ICM). Here we show that ICMs are spatially temporally localized in diverse patterns among PNSB. We visualized live cells 14 PNSB species across nine genera by exploiting natural autofluorescence photosynthetic pigment...
Bacterial locomotion driven by flagella is given directionality the chemotaxis signal transduction network. In classic plate assays of migration in porous motility agar, efficient compromised mutants diverse bacteria. Nonchemotactic become trapped within agar matrix. Suppressor mutations that prevent this entanglement but do not restore chemotaxis, a phenomenon designated pseudotaxis, were first reported to arise for Escherichia coli. study, novel mechanisms pseudotaxis have been identified...
We describe a microfluidic device with an integrated nanochannel array to trap individual bacteria and monitor growth reproduction of lineages over multiple generations. Our poly(dimethylsiloxane) comprises pneumatically actuated that includes 1280 channels widths from 600 1000 nm actively diverse bacteria. Integrated pumps valves perform on-chip fluid cell manipulations provide dynamic control loading nutrient flow, permitting chemostatic for extended periods time (typically 12 20 h)....
Motile bacteria bias the random walk of their motion in response to chemical gradients by process termed chemotaxis, which allows cells accumulate favorable environments and disperse from less ones. In this work, we describe a simple microchannel-nanopore device that establishes stable gradient for chemotaxis assays ≤1 min. Chemoattractant is dispensed diffusion through 10 nm diameter pores at intersection two microchannels. This design requires no external pump minimizes effect...