The roles of slow antibiotic penetration, oxygen limitation, and low metabolic activity in the tolerance of Pseudomonas aeruginosa in biofilms to killing by antibiotics were investigated in vitro. Tobramycin and ciprofloxacin penetrated biofilms but failed to effectively kill the bacteria. Bacteria in colony biofilms survived prolonged exposure to either 10 micro g of tobramycin ml(-1)or 1.0 mi...

Dental plaques are the biofilms or the microbial population associated with the oral cavity and is responsible for several clinical conditions that affect the host system. Despite the fact that, the oral micro flora offer certain benefit to the host by offering protection to the epithelial cell from damage and enhances the digestion of some substrates, their harmful consequences cannot be denie...

Transgenic alfalfa over-expressing a nodule-enhanced malate dehydrogenase (neMDH) cDNA and untransformed alfalfa plants were grown at the same field site and rhizosphere soils collected after 53 weeks of plant growth. These alfalfa lines differ in the amount and composition of root organic acids produced and exuded into the rhizosphere. Nucleotide sequencing of PCR-based 16S ribosomal DNA (rDNA...

We studied the growth of six culturable bacterial lineages from coastal North Sea picoplankton in environmental samples under different incubation conditions. The grazing pressure of heterotrophic nanoflagellates (HNF) was reduced either by double prefiltration through 0.8- micro m-pore-size filters or by 10-fold dilutions with 0.2- micro m (pore-size) prefiltered seawater. We hypothesized that...

BACKGROUND Bacteriophage survives in at least two extremes of ionic environments: bacterial host (high ionic-cytosol) and that of soil (low ionic-environmental water). The impact of ionic composition in the micro- and macro-environments has not so far been addressed in phage biology. RESULTS Here, we discovered a novel mechanism of aggregation/disaggregation transitions by phage virions. When...

background diazinon is one of the most widely used organophosphrous pesticides in the world may affect animals and human. objectives this study was done to assess whether pseudomonas plecoglossicida can grow on diazinon as the sole carbon metabolic source in laboratory and agricultural soil. materials and methods serial dilutions of pure and commercial diazinon in minimal salt medium were made ...

In aquifers subject to saline water intrusion, the mixing zone between freshwater and saltwater displays strong physico-chemical gradients. Although the microbial component of these specific environments has been largely disregarded, the contribution of micro-organisms to biogeochemical reactions impacting water geochemistry has previously been conjectured. The objective of this study was to ch...

There is increasing evidence that organic volatiles play an important role in interactions between micro-organisms in the porous soil matrix. Here we report that volatile compounds emitted by different soil bacteria can affect the growth, antibiotic production and gene expression of the soil bacterium Pseudomonas fluorescens Pf0-1. We applied a novel cultivation approach that mimics the natural...

OBJECTIVE To define an entity of abnormal vaginal flora: aerobic vaginitis. DESIGN Observational study. SETTING University Hospital Gasthuisberg, Leuven, Belgium. SAMPLE 631 women attending for routine prenatal care or attending vaginitis clinic. METHODS Samples were taken for fresh wet mount microscopy of vaginal fluid, vaginal cultures and measurement of lactate, succinate and cytokin...

Chitin is the second most produced biopolymer on Earth after cellulose. Chitin degrading enzymes are promising but untapped sources for developing novel industrial biocatalysts. Hidden amongst uncultivated micro-organisms, new bacterial enzymes can be discovered and exploited by metagenomic approaches through extensive cloning and screening. Enrichment is also a well-known strategy, as it allow...