Polyhedral vesicles

Polyhedral vesicles with a large bending modulus of the membrane such as the gel phase lipid membrane were studied using a Brownian dynamics simulation. The vesicles exhibit various polyhedral morphologies such as tetrahedron and cube shapes. We clarified two types of line defects on the edges of the polyhedrons: cracks of both monolayers at the spontaneous curvature of monolayer $C_{\text {0}}<0$, and a crack of the inner monolayer at $C_{\text {0}}\ge0$. Around the latter defect, the inner monolayer curves positively. Our results suggested that the polyhedral morphology is controlled by $C_{\text {0}}$.Comment: 4 pages, 5 figure

Bacillus cereus Spores Release Alanine that Synergizes with Inosine to Promote Germination

spores germinate in the presence of a single germinant, inosine, yet with a significant lag period. spores. spores appear to have developed a unique quorum-sensing feedback mechanism to monitor spore density and to coordinate germination

Enhanced germination rate of B. cereus spores germinated in conditioned supernatants.

<p>Wild-type <i>B. cereus</i> spores were germinated with a 0.2 mM inosine solution (•) or in conditioned supernatants containing 0.2 mM inosine (▪). <i>B. cereus</i> spores were also germinated with 0.2 mM inosine and 20 µM alanine (X).</p

<i>B. cereus</i> spore germination at low spore concentrations.

<p>(A) <i>B. cereus</i> spores were diluted in 10 or 4000 ml (OD₅₈₀ of 1 or 0.0025, respectively) of germination buffer supplemented with 0.2 mM inosine and 0 or 40 µM alanine. Thirty min post-inosine exposure, spores were collected by centrifugation, and pellets were treated with malachite green to stain resting spores and safranin-O to stain germinated cells. Samples were placed under a microscope and a field selected at random. (B) <i>B. cereus</i> spores were diluted in germination buffer (OD₅₈₀ of 1 to 0.0025) in the presence of 0.2 mM inosine. Stained samples were placed under a light microscope and the amount of resting spores and germinated cells were counted on three different fields selected at random. The percentage of germinated spores was plotted against the initial spore optical density.</p

7-AMC adducts detected in <i>wt B. cereus</i> conditioned supernatants.

<p>Wild type <i>B. cereus</i> 569 spores were resuspended in 200 µl TMB buffer to OD₅₈₀ = 1. Spores were treated with 0.2 mM inosine and supernatants were collected 30 min post-inosine addition. Collected supernatants were labeled with 7-AMC. 7-AMC adducts sere separated by RP-HPLC and identified by mass spectrometry. Concentrations were calculated by fluorescence spectroscopy.</p