Draft Genome Sequence of Pseudomonas brassicacearum Strain UTMN3, a Biological Control Agent from the Rhizosphere of Pisum sativum.

Here, we announce and describe the draft genome sequence of Pseudomonas brassicacearum UTMN3, which contains 40 contigs comprising 6,658,810 bp, with a GC content of 60.9%. The genome contains 5,825 protein-coding genes and 65 RNA-coding genes. The genome of UTMN3 contains several genes that are likely contributors to plant protection.

Genome Analysis of the Probiotic Strain Enterococcus faecium Ef79OSAU.

We report here the draft genome sequence of Enterococcus faecium strain Ef79OSAU, which was isolated from swine feces. The characteristics of strain Ef79OSAU reveal the absence of pathogenicity factors, a wide range of antimicrobial activity in vitro, and antilisteriosis activity in vivo. Analysis of the E. faecium Ef79OSAU genome revealed a cluster of genes encoding enterocin A without genetic determinants of pathogenicity.

Draft Genome Sequence of the Multiple Antibiotic Producer Bacillus velezensis X-BIO-1.

Here, we describe the draft genome sequence of Bacillus velezensis strain X-BIO-1, which contains 16 contigs, comprising 3,861,135 bp with a G+C content of 46.54%. The annotated draft genome contains 3,710 protein-coding genes and 62 RNA genes. We identified genes responsible for the synthesis of various antibiotics.

A Novel High-Molecular-Mass Bacteriocin Produced by Enterococcus faecium: Biochemical Features and Mode of Action.

Discovery of a novel bacteriocin is always an event in sciences, since cultivation of most bacterial species is a general problem in microbiology. This statement is reflected by the fact that number of bacteriocins is smaller for tenfold comparing to known antimicrobial peptides. We cultivated Enterococcus faecium on simplified medium to reduce amount of purification steps. This approach allows to purify the novel heavy weight bacteriocin produced by E. faecium ICIS 7. The novelty of this bacteriocin, named enterocin-7, was confirmed by N-terminal sequencing and by comparing the structural-functional properties with available data. Purified enterocin-7 is characterized by a sequence of amino acid residues having no homology in UniProt/SwissProt/TrEMBL databases: NH2 - Asp - Ala - His - Leu - Ser - Glu - Val - Ala - Glu - Arg - Phe - Glu - Asp - Leu - Gly. Isolated thermostable protein has a molecular mass of 65 kDa, which allows it to be classified into class III in bacteriocin classification schemes. Enterocin-7 displayed a broad spectrum of activity against some Gram-positive and Gram-negative microorganisms. Fluorescent microscopy and spectroscopy showed the permeabilizing mechanism of the action of enterocin-7, which is realized within a few minutes.

Antimicrobial activity of the indolicidin-derived novel synthetic peptide In-58.

Natural peptides with antimicrobial activity are extremely diverse, and peptide synthesis technologies make it possible to significantly improve their properties for specific tasks. Here, we investigate the biological properties of the natural peptide indolicidin and the indolicidin-derived novel synthetic peptide In-58. In-58 was generated by replacing all tryptophan residues on phenylalanine in D-configuration; the α-amino group in the main chain also was modified by unsaturated fatty acid. Compared with indolicidin, In-58 is more bactericidal, more resistant to proteinase K, and less toxic to mammalian cells. Using molecular physics approaches, we characterized the action of In-58 on bacterial cells at the cellular level. Also, we have found that studied peptides damage bacterial membranes. Using the Escherichia coli luminescent biosensor strain MG1655 (pcolD'::lux), we investigated the action of indolicidin and In-58 at the subcellular level. At subinhibitory concentrations, indolicidin and In-58 induced an SOS response. Our data suggest that indolicidin damages the DNA, but bacterial membrane perturbation is its principal mode of action. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

Novel haemoglobin-derived antimicrobial peptides from chicken (Gallus gallus) blood: purification, structural aspects and biological activity.

AIM: To purify and characterize antimicrobial peptides derived from the acid extract of Gallus gallus blood cells. METHODS AND RESULTS: Two polypeptides (i.e. CHb-1 and CHb-2) with antibacterial activity were detected in the acidic extract of blood cells from chicken (G. gallus). The isolated peptides that possessed a potent antibacterial activity were purified using a two-step chromatography procedure that involved solid-phase extraction of a total protein/peptide extract followed by thin fractionation by reversed-phase high performance liquid chromatography (RP-HPLC). The molecular masses of the purified peptides were similar and were 4824·4 and 4825·2 Da, which have been measured by matrix-assisted laser desorption/ionization mass spectrometry (MALDI TOF MS). Their amino acid sequences were determined by Edman degradation and showed that the peptides were fully identical to the two fragments of G. gallus α-haemoglobin localized into different subunits (A and D respectively). The peptides were active in micromolar concentrations against Gram-negative Escherichia coli K12 TG1. Using the 1-N-phenylnaphthylamine, the FITC-dextran labelled probes and the live/dead staining allowed to show the hemocidin mode of action and estimate the pore size. CONCLUSION: In this study, for the first time, α-haemoglobin from chicken (G. gallus) has been investigated as a donor of the two high homologous native peptide fragments that possess potent antibacterial activity in vitro. These are membrane-active peptides and their mechanism of action against E. coli involves a toroidal pore formation. SIGNIFICANCE AND IMPACT OF THE STUDY: The obtained results expand the perception of the role of haemoglobin in a living system, describing it as a source of multifunction substances. Additionally, the data presented in this paper may contribute to the development of new, cost-effective, antimicrobial agents.