Development of methods for quantification of cellular association and patterns in growing bacterial colony is of considerable current interest, not only to help understand multicellular behavior of a bacterial species but also to facilitate detection and identification of a bacterial species in a given space and under a given set of condition(s). We have explored quantitative spectral light sca...

Plant activators are chemicals that induce disease resistance. The phytohormone salicylic acid (SA) is a crucial signal for systemic acquired resistance (SAR), and SA-mediated resistance is a target of several commercial plant activators, including Actigard (1,2,3-benzothiadiazole-7-thiocarboxylic acid-S-methyl-ester, BTH) and Tiadinil [N-(3-chloro-4-methylphenyl)-4-methyl-1,2,3-thiadiazole-5-c...

Matrix assisted laser desorption ionization time of flight mass spectrometry has been explored as a tool to bacterial colony morphotyping. To this end, four colony morphotypes of Pseudomonas aeruginosa and four of Staphylococcus aureus were analysed using intact bacteria. Results suggest that mass spectrometry of intact bacteria could, in some extent, be used to complement the classical morphol...

On agar surface, bacterial daughter cells form a 4-cell array after the first two rounds of division, and this phenomenon has been previously attributed to a balancing of interactions among the daughter bacteria and the underneath agar. We studied further the organization and development of colony after additional generations. By confocal laser scanning microscopy and real-time imaging, we obse...

Most studies on phosphorus cycle in the natural environment focused on phosphates, with limited data available for the reduced phosphine (PH3). In this paper, matrix-bound phosphine (MBP), gaseous phosphine fluxes and phosphorus fractions in the soils were investigated from a penguin colony, a seal colony and the adjacent animal-lacking tundra and background sites. The MBP levels (mean 200.3 ng...

We analyze the phenomenon of spreading of a Myxococcus xanthus bacterial colony on plates coated with nutrient. The bacteria spread by gliding on the surface. In the first few hours, cell growth is irrelevant to colony spread. In this case, bacteria spread through peninsular protrusions from the edge of the initial colony. We analyze the diffusion through the narrowing reticulum of cells on the...

Qualitative and quantitative aspects of bacterial challenges that might be encountered in food are discussed with reference to recognized and relatively unrecognized hazards. Mechanisms of pathogenicity are reviewed and the populations at risk are noted. The bacterial content of food as it is served at table merits more study. The challenge of prevention by education is discussed. Indirect bact...

In this Note we report the attempt of generalization of Mimura et al. (MSM) model for colony formation of bacteria. We also show the numerical results, which are then compared with experiments. Bacterial species Bacillus subtilis exhibits various colony patterns in response to two environmental parameters, i.e., concentrations of nutrient Cn and agar Ca in a thin agar plate as incubation medium...

This study was designed to evaluate the measuring range and lowest limit of detection of Bacillus endospores in the ambient room air when the Sartorius MD8 sampler, and two different culture methods for bacterial enumeration were used. Different concentrations of bioaerosol were generated inside the test chamber filled with either the high-efficiency particulate air (HEPA)-filtered air or with ...