Study of lysozyme by a spin-label method in the 2-mm range

Two millimeter range ESR-spectroscopy was used to measure the values of magnetic resonance parameters of egg lysozyme samples modified with nitroxyl label 4-(iodine-acetamide)-2,2,6,6-tetramethylpiperidine-1-oxyl by hist-15 residue. It has been shown that in a lyophilic sample the spin label forms a hydrogen bond with the protein group and when the sample is moistened--with water molecules. Temperature changes of the pattern of ESR line are analysed. It is concluded that in the moistened samples within 230-320 K the nitroxyl fragment of the label gets engaged in anisotropic movement with preferable rotation around Z-axis of N-O. fragment with anisotropy coefficient 5 and mean correlation time tau congruent to 5 X 10(-7) divided by 5 X 10(-8) c.     

Two-way microscale interactions between immigrant bacteria and plant leaf microbiota as revealed by live imaging

The phyllosphere – the aerial parts of plants – is an important microbial habitat that is home to diverse microbial communities. The spatial organization of bacterial cells on leaf surfaces is non-random, and correlates with leaf microscopic features. Yet, the role of microscale interactions between bacterial cells therein is not well understood. Here, we ask how interactions between immigrant bacteria and resident microbiota affect the spatial organization of the combined community. By means of live imaging in a simplified in vitro system, we studied the spatial organization, at the micrometer scale, of the biocontrol agent Pseudomonas fluorescens A506 and the plant pathogen P. syringae B728a when introduced to pear and bean leaf microbiota (the corresponding native plants of these strains). We found significant co-localization of immigrant and resident microbial cells at distances of a few micrometers, for both strains. Interestingly, this co-localization was in part due to preferential attachment of microbiota cells near newly formed P. fluorescens aggregates. Our results indicate that two-way immigrant bacteria – resident microbiota interactions affect the microscale spatial organization of leaf microbiota, and possibly that of other surface-related microbial communities.Subject terms: Microbial ecology, Microbial ecology     

Dynamics of changes in human cells with chromosome and genetic mutations in prolonged cultivation in a stationary phase. Report 1. Study of cells in xeroderma pigmentosum]

Ontogenetic changes of normal diploid cells and cells with genetic mutations (LHC-484 from a patient with xeroderma pigmentosum) have been studied under prolonged cultivation in a stationary phase. While investigating the dynamics of complex changes in certain cell properties and cell populations it was found that the cultivated human cells possess a particular pattern of ontogenetic changes for every culture and the dynamics of these changes depends upon the density of the cell population. Two cell subpopulations different in the degree of nucleus heterochromotinization have been discovered.