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Studies on megacinogeny in Bacillus cereus. I. Multiplication of phage wx causing lysogenic conversion to megacin A
Abstract:
Phage wx capable of reconverting Bacillus cereus strain W derivatives, cured to lose megacin A (phospholipase A) production into megacin A-producing cultures, exhibits unusual kinetics of multiplication; its clear mutant, phage wxc, behaves similarly. The phages are not adsorbed by stationary phase indicator bacteria. As sonicated bacteria fail to inactivate the phages, the absence of adsorption cannot be attributed to an undersurface localization of the receptors. Multiplying bacteria exert a slow and slight degree of phage adsorption. Cells inhibited by chloramphenicol produce no receptors. It has been assumed that the receptor, produced from a precursor involved in bacterial cell synthesis, either absorbs the phage in the nascent state or is incorporated in the cell and loses its phage-adsorbing capacity.
Insights
Phage wx reconverts Bacillus cereus to produce megacin A, showing unique multiplication. Bacterial cell synthesis is key for phage receptor production and adsorption.
Area of Science:
- Microbiology
- Bacteriology
- Virology
Background:
- Bacillus cereus strain W can lose megacin A (phospholipase A) production.
- Phage wx can restore megacin A production in cured derivatives.
- Phage wx exhibits unusual multiplication kinetics.
Purpose of the Study:
- To investigate the adsorption and multiplication kinetics of phage wx and its clear mutant, phage wxc.
- To understand the nature of phage receptors in Bacillus cereus.
Main Methods:
- Studying phage adsorption to stationary and multiplying Bacillus cereus cells.
- Investigating the effect of chloramphenicol on receptor production.
- Examining the role of bacterial cell synthesis in phage receptor formation.
Main Results:
- Phages wx and wxc showed slow and slight adsorption to multiplying bacteria.
- Stationary phase bacteria and sonicated bacteria did not adsorb the phages.
- Chloramphenicol-inhibited cells failed to produce phage receptors.
- Receptor production is linked to bacterial cell synthesis.
Conclusions:
- Phage adsorption is dependent on active bacterial cell synthesis.
- Receptors may be formed during bacterial cell division or integrated into the cell membrane.
- The unusual kinetics are related to the phage-receptor interaction during bacterial growth.