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Bacteriophage-enhanced sporulation: comparison of spore-converting bacteriophages PMB12 and SP10
T H Silver-Mysliwiec1, M G Bramucci
1Department of Microbiology and Immunology, Hahnemann University, Philadelphia, Pennsylvania 19102.
Abstract:
The previously characterized bacteriophage SP10 enhanced the frequency of wild-type sporulation by Bacillus subtilis W23 and 3-13. Comparison of SP10 with the spore-converting bacteriophage PMB12 indicated that both bacteriophages significantly increased the sporulation frequency of an oligosporogenic mutant that contained spo0J::Tn917 omega HU261. SP10 and PMB12 caused wild-type bacteria to sporulate in a liquid medium that initially contained enough glucose to inhibit the sporulation and expression of alpha-amylase by uninfected bacteria. SP10 also induced the expression of alpha-amylase in the presence of glucose, whereas PMB12 had no detectable effect. These observations were consistent with the conclusion that SP10 is a spore-converting bacteriophage and that SP10 and PMB12 relieve glucose-mediated catabolite repression of sporulation by different mechanisms.
Insights
Bacteriophage SP10 boosts Bacillus subtilis sporulation, even under glucose inhibition. SP10 and PMB12 aid sporulation in mutants, with SP10 uniquely inducing alpha-amylase expression despite glucose presence.
Area of Science:
- Microbiology
- Molecular Biology
- Bacteriology
Background:
- Bacterial sporulation is a crucial survival mechanism in Bacillus subtilis.
- Sporulation is tightly regulated by environmental factors, including nutrient availability (e.g., glucose).
- Bacteriophages can influence bacterial physiology, including sporulation.
Purpose of the Study:
- To investigate the effect of bacteriophage SP10 on Bacillus subtilis sporulation frequency.
- To compare the sporulation-enhancing capabilities of SP10 with another spore-converting bacteriophage, PMB12.
- To elucidate the mechanisms by which these bacteriophages overcome glucose-mediated catabolite repression of sporulation.
Main Methods:
- Comparative analysis of sporulation frequencies in wild-type and mutant Bacillus subtilis strains.
- Infection of bacteria with bacteriophages SP10 and PMB12.
- Measurement of sporulation and alpha-amylase expression under varying glucose concentrations.
- Assessment of bacteriophage effects on oligosporogenic mutants.
Main Results:
- Bacteriophage SP10 significantly enhanced sporulation frequency in wild-type Bacillus subtilis strains.
- Both SP10 and PMB12 increased sporulation in an oligosporogenic mutant (spo0J::Tn917 omega HU261).
- SP10 induced sporulation and alpha-amylase expression in the presence of inhibitory glucose levels, while PMB12 did not induce alpha-amylase.
Conclusions:
- Bacteriophage SP10 acts as a spore-converting bacteriophage.
- SP10 and PMB12 can relieve glucose-mediated catabolite repression of sporulation in Bacillus subtilis.
- SP10 and PMB12 employ distinct mechanisms to overcome glucose repression, with SP10 also inducing specific gene expression (alpha-amylase).