Analysis of Bacillus subtilis sporulation with spore-converting bacteriophage PMB12

Abstract

Previous observations concerning the ability of the spore-converting bacteriophage PMB12 to cause sporulation in certain sporulation-deficient mutants of Bacillus subtilis 168 were extended to include a spoOK mutant and a mutant temperature sensitive for sporulation due to a ribosomal mutation. Mutants of PMB12 that were unable to induce sporulation in the spoOK mutant were isolated to determine whether PMB12-encoded products had to affect the sporulation-specific functions of both the transcription and the translation systems of B. subtilis to induce sporulation. A complementation assay for spore conversion was used to assign the spore conversion-negative PMB12 mutants to four groups. One group of mutants repressed the ability of wild-type PMB12 to induce sporulation. None of the spore conversion-negative PMB12 mutants could induce significant levels of sporulation in B. subtilis mutants that were temperature sensitive for sporulation due to mutations in the beta subunit of ribonucleic acid polymerase or the 30S ribosomal subunit. Our data suggest that PMB12 may have at least three genes for spore conversion. The products of these genes apparently interact with a host cell pathway that is expressed during the earliest stage of sporulation and is not dependent for expression upon sporulation-specific functions of the host cell's transcription and translation systems.

Bacillus subtilis sporulation: regulation of gene expression and control of morphogenesis.

“…Originally, a second mutation, spo-87, was also placed in the spoOJ locus, but it is now known to lie in a separate locus, spoIIIJ, concerned with stage III of sporulation (68). spoOJ is one of only two spoO loci (the other being spoOK) that can be bypassed by infection with the spore-converting phages PMB12 and SP10 (159,257). Following infection, spore-converting phages somehow intervene in the control mechanisms of sporulation in such a way that they advance its onset.…”

Characterization ofBacillus subtilissporulation and bacteriophage infection via FT-IR spectroscopy

“…These bacteriophages form unstable pseudolysogenic carrier states within the host cell and induce sporulation in wildtype cells [13,18]. It has been suggested that spore-converting bacteriophages induce sporulation in wild-type cells so that the bacteriophage DNA becomes trapped within the developing spores [19,20]. When environmental conditions improve, the carrier spore germinates, and trapped bacteriophage DNA can direct lytic development in the progeny of the germinated cell.…”

Host control by SPβ phage regulatory switch as potential manipulation strategy

“…During lysogeny, phage DNA integrates into the host genome at specific or random attachment site (att) and replicates within the host chromosome as a prophage. It is well established that during lysogeny, phages can influence a versatility of bacterial behaviors such as production of toxins, bacteriocins [12] or antiviral defense systems [13], metabolic enzymes [14], surface attachment proteins [15], temporal changes or restoration of dormancy [16,17], production of new signaling molecules [18], or they are even involved in cell gigantism [9]. As some of these traits clearly benefit the host, lysogeny is often viewed as host-phage mutualism [19].…”