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Phages of phytopathogenic bacteria are considered to be promising agents for the biological control of bacterial diseases in plants. This paper reports on the isolation and characterisation of a new Xanthomonas campestris pv. campestris phage, Murka. Phage morphology and basic kinetic characteristics of the infection were determined, and a phylogenomic analysis was performed. The phage was able to lyse a reasonably broad range (64%, 9 of the 14 of the Xanthomonas campestris pv. campestris strains used in the study) of circulating strains of the cabbage black rot pathogen. This lytic myovirus has a DNA genome of 44,044 bp and contains 83 predicted genes. Taxonomically, it belongs to the genus Foxunavirus. This bacteriophage is promising for use as a possible means of biological control of cabbage black rot. [ABSTRACT FROM AUTHOR]

Representatives of the genus Beijerinckia are known as heterotrophic, dinitrogen-fixing bacteria which utilize a wide range of multicarbon compounds. Here we show that at least one of the currently known species of this genus, i.e., Beijerinckia mobilis, is also capable of methylotrophic metabolism coupled with the ribulose bisphosphate (RuBP) pathway of [C.sub.1] assimilation. A complete suite of dehydrogenases commonly involved in the sequential oxidation of methanol via formaldehyde and formate to C[O.sub.2] was detected in cell extracts of B. mobilis grown on C[H.sub.3]OH. Carbon dioxide produced by oxidation of methanol was further assimilated via the RuBP pathway as evidenced by reasonably high activities of phosphoribulokinase and ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). Detection and partial sequence analysis of genes encoding the large subunits of methanol dehydrogenase (mxaF) and form I RubisCO (cbbL) provided genotypic evidence for methylotrophic autotrophy in B. mobilis.

Summary: Phycisphaera‐like WD2101 'soil group' is one of the as‐yet‐uncultivated phylogenetic clades within the phylum Planctomycetes. Members of this clade are commonly detected in various terrestrial habitats. This study shows that WD2101 represented one of the major planctomycete groups in 10 boreal peatlands, comprising up to 76% and 36% of all Planctomycetes‐affiliated 16S rRNA gene reads in raised bogs and eutrophic fens respectively. These types of peatlands displayed clearly distinct intra‐group diversity of WD2101‐affiliated planctomycetes. The first isolate of this enigmatic planctomycete group, strain M1803, was obtained from a humic lake surrounded by Sphagnum peat bogs. Strain M1803 displayed 89.2% 16S rRNA gene similarity to Tepidisphaera mucosa and was represented by motile cocci that divided by binary fission and grew under micro‐oxic conditions. The complete 7.19 Mb genome of strain M1803 contained an array of genes encoding Planctomycetal type bacterial microcompartment organelle likely involved in l‐rhamnose metabolism, suggesting participation of M1803‐like planctomycetes in polysaccharide degradation in peatlands. The corresponding cellular microcompartments were revealed in ultrathin cell sections. Strain M1803 was classified as a novel genus and species, Humisphaera borealis gen. nov., sp. nov., affiliated with the formerly recognized WD2101 'soil group'. [ABSTRACT FROM AUTHOR]

Spray drying is appropriate for the preservation of halophilic microorganisms due to the nature of these microorganisms, as they survive in adverse environmental conditions by being encapsulated in salt crystals. Artificial neural networks were in this study used to optimize practically significant spray-drying regimes of the C50-carotenoids producer Halobacterium salinarum. Immediately after drying, the samples contained up to 54% halobacterial biomass and less than 5% moisture, and the level of preservation of carotenoids was 95-97%. The storage of biomass at 4 °C resulted in the gradual degradation of the carotenoids, which reached 58-64% in the best samples after 1 year. A comprehensive study of changes in halobacteria biomass after spray drying and the nature of the damage provided new data on the survival and preservation of cells and biologically active substances in the various spray-drying regimes and at different storage times. [ABSTRACT FROM AUTHOR]

The Gram-negative bacterium Lysobacter sp. XL1 forms vesicles and, using them, secretes an extracellular protein, bacteriolytic endopeptidase L5. Fractionation of a Lysobacter sp. XL1 vesicle preparation in a sucrose density gradient yielded four vesicle fractions of 30%, 35%, 40% and 45% sucrose. The size of most vesicles concentrated in 30% and 35% sucrose fractions were 40-65 and 65-100 nm, respectively. Electrophoresis and immunoblotting showed vesicles of the 30% fraction differed from those in the other fractions not only in density but also in protein content. Protein L5 was found to be secreted into the extracellular medium only by means of vesicles of the 30% sucrose fraction. Electron microscopic immunocytochemistry of Lysobacter sp. XL1 cells showed protein L5 to be distributed unevenly along the periplasmic space and to be concentrated in certain periplasmic loci adjacent to the outer membrane. It was in those loci where vesiculation occurred. A model of the formation of Lysobacter sp. XL1 vesicles is proposed based on the data obtained. [ABSTRACT FROM AUTHOR]

Membrane vesicles produced by bacteria have been intensively studied in the recent years. Investigators have noted their roles in essential processes in the bacterial cell including secretion of proteins by the 'eukaryotic' vesicular mechanism. To date, formation of vesicles is not considered to be a spontaneous event. Many believe it to be a programmed process that can be guided by several mechanisms. Vesicles are derivatives of the cell envelope, which in turn is a supramolecular structure where the functioning and biogenesis of all components are interrelated. Proteins secreted beyond the cell in their translocation are also part of the cell envelope. This also suggests their role in vesicle biogenesis. This review presents the results of vesicle studies in the Gram-negative bacterium Lysobacter sp. This bacterium is of interest as it secretes a number of proteins to the environment, including bacteriolytic enzymes. Bacteriolytic enzymes, on the one hand, are important for studies from a medical point of view as they can form the basis of new generation antimicrobial means. On the other hand, they are a convenient subject for studies of vesicle functions in the vital activities of the bacterial cell. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]