Biodiversity Of Bacteriophages From Lysed Batch Culture Of Recombinant Escherichia Coli BL21(DE3) Examined By Anion Exchange Chromatography And TEM

It was found that the phage population assaulted a batch culture of an industrial recombinant derivative of E. coli BL21(DE3) was attenuated that manifested in producing pinprick-type plaques and their inability to propagation in subsequent passages. Because of this, the goals of the present research were to evaluate biodiversity and scrutinize the possible virion structural defects of the attenuated phage population prior to pure phage lines isolation. The anion exchange chromatography (AEC) was chosen as the principal method allowing to get a comparative phage population profile based on the virion net surface charge, as well as to treat the 5-liter virion-contained sample and collect high-quality concentrated and separated phage fractions to further analysis. The isolate consisted of a mix of two phages belonging to Myoviridae (A2-morphotype) and Siphoviridae (B1-morphotype) families. By restriction analysis, the main portion of this phage pool (about 99% of all virions) was identified as the primary population of myophage Lw1, which possessed its own intra-population biodiversity (heterogeneity). It consisted of a major and two minor subpopulations that differed by phage capsid size and shape. The subpopulation III consisted of aberrant tubby-phages with triprolate (expanded at both sides) capsids having low aspect ratio.