Five Unique Temperate Phages from a Polylysogenic Strain of Bacillus thuringiensis Subsp. aizawai

Abstract

Five temperate phages were isolated from strain 4042B of Bacillus thuringiensis subsp. aizawai. The phages, which were heteroimmune, could also be distinguished by their host ranges, plaque and particle morphologies, serological specificities, and locations of restriction endonuclease cleavage sites on their chromosomes. Besides maintaining a stable lysogenic relationship with the 4042B host strain, each phage formed a stable lysogen with Bacillus cereus. I N T R O D U C T I O NStrains of Bacillus thuringiensis have elicited a special interest because they produce a proteinaceous parasporal crystal that is toxic to susceptible insect larvae. Since this commercially important species has only limited means of genetic exchange, temperate phages could be important genetic tools, serving as mediators of generalized and specialized transduction and as potential cloning vehicles. We have thus been interested in the characterization of temperate phages from this species.Past surveys of strains of B. thuringiqzsis have suggested that a significant proportion harbour one or more temperate phages (Colasito & Rogoff, 1969;Ackermann & Smirnoff, 1978;Jones et al., 1983). However, the physical characteristics of these phages, as well as their relationships with the host strains, have not been examined in detail. Several phages that mediate generalized transduction in B. thuringiensis (Thorne, 1978 During our investigation of strain 4042B of B. thuringiensis subsp. aizawai, we isolated five unique temperate phages whose characteristics are described in this report. The phages are heteroimmune and they can be distinguished on the basis of plaque and particle morphology, host range, antigenicity and restriction endonuclease digestion patterns of their DNAs. METHODSBacterial strains. Derivatives of B. thuringiensis 4042B and other strains that were used for detection or propagation of phages are listed in Table I. Strains that were used only for the determination of phage host ranges are included in Table 2

Enterococcus faecalis Prophage Dynamics and Contributions to Pathogenic Traits

“…Polylysogeny is found in a variety of bacterial species, including E. faecalis [46], and it is frequently considered as the result of an adaptive evolution process in which prophages are maintained as they confer advantageous properties to the bacterial strains [35], [60]–[64]. As a way to maintain and propagate themselves, prophages interfere with each other through a variety of mechanisms in different bacterial species [31], [62], [65].…”

Phages Preying on Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis: Past, Present and Future

“…Lastly, several other temperate phages have also been studied in B. thuringiensis mainly because they accounted for an important reduction—sometimes up to 50%–80%—of the spores and crystal production during fermentations [55,93,94,121,163,164]. However, the available information for these phages is scarce and limited, and therefore they were not included in the present review.…”

Within-host competition determines reproductive success of temperate bacteriophages

“…Bacteria are susceptible to many phages, which can integrate into the same host genome if they use different insertion sites (Campbell, 2003). Consequently, polylysogens, cells harboring several different prophages, are found in a variety of bacterial species (Reynolds et al, 1988;Espeland et al, 2004;Asadulghani et al, 2009). Finally, phages contain a vast amount of genetic diversity, to which recombination has contributed an important part, indicating that multiple infections have always played a role in phage biology (Hendrix, 2002).…”