Related Experiment Videos
Macromolecular synthesis during microcycle sporogenesis of Bacillus cereus T
Abstract:
Microcycle sporogenesis induced in Bacillus cereus T by phosphate limitation occurs over a narrow range of phosphate to spore inoculum ratios. Sufficient phosphate is required to satisfy the demands for a twofold increase in deoxyribonucleic acid; net ribonucleic acid synthesis is not required. The total ribonucleic acid content of the culture was variable, and deoxyribonucleic acid synthesis was restricted to a twofold increase. Developmental changes during outgrowth occurred synchronously, whereas enzyme synthesis was periodic. The timing of the synthesis of tricarboxylic cycle enzymes, extracellular protease, arginase, histidase, and alkaline phosphatase was measured. Histidase could be induced after 2.5 hr throughout microcycle sporogenesis. Several other features of macromolecular synthesis during microcycle sporogenesis are described. Differences between this pattern and those observed during outgrowth leading to cell division are discussed. A technique for accurately estimating the levels and time of synthesis of incompletely extractable, labile enzymes is also presented.
Insights
Phosphate limitation triggers Bacillus cereus microcycle sporogenesis, requiring sufficient phosphate for deoxyribonucleic acid replication but not ribonucleic acid synthesis. Enzyme synthesis during this process is periodic, not synchronous.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Bacillus cereus T undergoes microcycle sporogenesis under phosphate limitation.
- This process involves specific requirements for nucleic acid synthesis and exhibits distinct developmental patterns compared to cell division outgrowth.
Purpose of the Study:
- To investigate the phosphate requirements for microcycle sporogenesis in Bacillus cereus T.
- To characterize macromolecular synthesis, developmental changes, and enzyme production during this process.
- To compare microcycle sporogenesis with outgrowth leading to cell division.
Main Methods:
- Induction of microcycle sporogenesis via phosphate limitation.
- Quantification of deoxyribonucleic acid and ribonucleic acid synthesis.
- Measurement of enzyme synthesis timing (tricarboxylic acid cycle enzymes, extracellular protease, arginase, histidase, alkaline phosphatase).
- Development of a technique for estimating labile enzymes.
Main Results:
- Sporogenesis occurs within a narrow phosphate to spore inoculum ratio range.
- Phosphate sufficiency is essential for a twofold increase in deoxyribonucleic acid, but not net ribonucleic acid synthesis.
- Developmental changes are synchronous, while enzyme synthesis is periodic.
- Histidase induction is possible throughout microcycle sporogenesis.
Conclusions:
- Phosphate availability critically regulates Bacillus cereus microcycle sporogenesis.
- The process is characterized by specific nucleic acid synthesis patterns and periodic enzyme production.
- Distinct differences exist between microcycle sporogenesis and outgrowth leading to cell division.