| Abstract [eng] |
The purpose of this paper was to characterize physicochemical, morphological and genomic properties of 4 newly isolated bacteriophages from Myoviridae family. Four phages (vB_LadM-OB5, vB_ValM-AVI3, vB_LniM-OBL4A, and vB_LniM-OBL4D), infecting different bacterial strains from Enterobacteriaciae and Vibrionaceae family, were isolated and used in this work. Physicochemical analysis of all phages was focused on effect determination of thermal inactivation, sensitivity to low and high pH, sensitivity to osmotic stress and survivability upon treatment with organic solvents and detergents. Genetic analysis was focused on restriction analysis (identifying possible genome modifications) and bioinformatics analysis of genome fragments (identifying homology to known viruses). Morphological analysis was focused on determination of depolymerase activity. Depolymerase activity was detected in vB_LniM-OBL4D phage, infecting Leclercia adecarboxylata OB5 strain. Thermal inactivation results showed that all 4 bacteriophages remain stable after freezing, but are very sensitive to thermal denaturation. Osmotic shock results showed that all phages have high survival rate after induction of osmotic shock. Analysis of different pH effects showed low survival rate of all 4 bacteriophages at acidic pH, but infectivity rates are also negatively affected by alkaline pH. Analysis of the effects of detergents and organic solvents showed that all phages have high resistance to ethanol and chloroform, but the infectivity rates decrease the most after exposure to acetone. Restriction analysis of phage DNA showed that phage vB_ValM-AVI3 has modified DNA, and that other phages may have unique genome sequences or unidentified genome modifications, which could serve as an anti-restriction system. Bioinformatics analysis of the genome restricts of vB_ValM-AVI3 phage revealed no homology to previously known proteins or nucleotide sequences. Bioinformatics analysis of other phages revealed that their protein-coding genes have homologues in other phages, mostly infecting bacteria from Enterobacteriaceae family. |
