PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 15681651

Pattern formation by bacteria-driven flow.

N G Cogan·Charles W Wolgemuth
View original source ↗Export metadata ↓

Abstract

Some marine bacterial species form mucosal layers, called veils, on sulfidic marine sediment. The bacteria attached to this veil actively swim and exert force on the surrounding fluid. The bacteria can break free of the veil and swim, chemotacting back to the veil. Over time the veil forms holes arranged in a hexagonal pattern. Motivated by this system, we present a simplified model to describe pattern formation induced by force-generating bodies embedded in a layer surrounded by fluid. When the bacteria break free of the layer, they are advected by the flow and diffuse. Competition between the fluid flow generated by the embedded bacteria and diffusion of the swimmers leads to a novel instability that drives bacterial aggregation. Analytic and numeric analysis of this system correctly defines the length scale and developmental timescale for the biological system. Similar flow dynamics may also play a role in other biological systems such as encrusting bryozoan colonies.

Explore related subjects

Bacterial Physiological PhenomenaBiofilmsBiophysicsChemotaxisModels, BiologicalModels, TheoreticalMovementOxygen ConsumptionProteobacteriaSeawaterTime FactorsWater MicrobiologyJournal ArticleResearch Support, N.I.H., ExtramuralResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

N G Cogan, Charles W Wolgemuth. 2005-01-28. Pattern formation by bacteria-driven flow.. https://doi.org/10.1529/biophysj.104.053348

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

An experimental metagenome data management and analysis system.

The application of shotgun sequencing to environmental samples has revealed a new universe of microbial community genomes (metagenomes) involving previously uncultured organisms. Metagenome analysis, which is expected to provide a comprehensive picture of the gene functions and metabolic capacity for microbial communities, needs to be conducted in the context of a comprehensive data management and analysis system. We present in this paper IMG/M, an experimental metagenome data management and analysis system that is based on the Integrated Microbial Genomes (IMG) system. IMG/M provides tools and viewers for analyzing both metagenomes and isolate genomes individually or in a comparative context. IMG/M is available at http://img.jgi.doe.gov/m.

Bacterial Physiological Phenomena↗
PubMed2006

Surprising niche for the plant pathogen Pseudomonas syringae.

The biology and ecology of plant pathogenic bacteria have been studied almost exclusively in agricultural contexts. In contrast, for numerous human pathogens their biological activity in niches outside of medical contexts is well-known. Whereas there is increasing evidence that traits fostering survival in 'environmental' niches can be the basis for virulence factors of human pathogens, niches for plant pathogenic bacteria outside of plants or of agricultural settings have not been elucidated. Most phytopathogenic bacteria are not obligate parasites, some of them can be transported to altitudes of several kilometres, they are scrubbed from the atmosphere by rainfall, and thus they are presumably transported to and might survive in a wide range of habitats. We isolated Pseudomonas syringae from river epilithon (rock-attached biofilms composed of algae, diatoms, rotifers, bacteria and nematodes) at densities up to 6000 cells g(-1) in France and the USA, some in pristine settings where waters flowed directly from snow melt and had not passed through agricultural zones. These strains induced hypersensitivity in indicator plants (tobacco) suggesting the presence of functional pathogenicity systems, and many induced disease in 1-7 of the plant species tested and produced a syringomycin-like toxin. Strains also were resistant to some antibiotics used to control plant diseases but not to copper sulphate. Sequencing of the 16S rDNA of epilithon strains and of reference strains of P. syringae revealed that a genetic lineage containing the strains with the broadest host range was distributed across several continents. Is it likely that wide spread dissemination of P. syringae occurs via aerosols and precipitation. This work highlights our limited understanding of non-agricultural niches in the ecology and evolution of plant pathogenic bacteria, of their role in the development of agricultural epidemics both as sources of inoculum and as sources of novel traits that may enhance bacterial pathogenicity and fitness.

Bacterial Physiological Phenomena↗
PubMed2006

The Planctomycetes, Verrucomicrobia, Chlamydiae and sister phyla comprise a superphylum with biotechnological and medical relevance.

In the rRNA-based tree of life four bacterial phyla, comprising the Planctomycetes, Verrucomicrobia, Chlamydiae and Lentisphaerae, form together with the candidate phyla Poribacteria and OP3 a monophyletic group referred to as the PVC superphylum. This assemblage contains organisms that possess dramatically different lifestyles and which colonize sharply contrasting habitats. Some members of this group are among the most successful human pathogens, others are abundant soil microbes, and others still are of major importance for the marine nitrogen cycle and hold much promise for sustainable wastewater treatment. Recent comparative genomic and metagenomic analyses of a few representatives of this group revealed many unusual features and generated unexpected hypotheses regarding their physiology, some of which have already been confirmed experimentally. Furthermore, the availability of these genome sequences offered new insights into the evolutionary history of this peculiar group of microbes with major medical, ecological and biotechnological relevance.

Bacterial Physiological Phenomena↗