A STUDY OF PNEUMOCOCCUS AUTOLYSIS

Area of Science:

• Microbiology
• Biochemistry
• Enzymology

Background:

• Pneumococcus undergoes autolysis, a process involving cellular breakdown.
• Autolysis is associated with the release of intracellular components and enzymatic activity.

Purpose of the Study:

• To investigate the enzymatic processes, specifically proteolysis and lipolysis, during Pneumococcus autolysis.
• To compare spontaneous autolysis with cell lysis induced by intracellular enzyme extracts.
• To examine the effect of sodium desoxycholate on Pneumococcus lysis and its relationship to enzymatic activity.

Main Methods:

• Analysis of nitrogenous compounds (amino and non-coagulable nitrogen) during autolysis.
• Quantification of ether-soluble fatty acids released during lipolysis.
• Incubation of heat-killed pneumococci and lipoid emulsions with intracellular enzyme extracts.
• Assessment of Pneumococcus lysis and enzymatic activity in the presence of sodium desoxycholate at low temperatures.

Main Results:

• Autolysis of Pneumococcus results in increased amino and non-coagulable nitrogen (proteolysis) and liberation of ether-soluble fatty acids (lipolysis).
• Intracellular enzyme extracts induced lysis of heat-killed pneumococci and lipoid emulsions, mirroring spontaneous autolysis.
• Sodium desoxycholate inhibited pneumococcus protease but not lipase.
• Rapid dissolution of pneumococci in sodium desoxycholate at 0°C occurred without significant lipolysis or proteolysis.

Conclusions:

• Pneumococcus autolysis is characterized by coordinated proteolysis and lipolysis.
• The mechanism of cell dissolution by sodium desoxycholate at low temperatures differs from spontaneous autolysis.
• Enzyme action plays a crucial role in Pneumococcus autolysis and may relate to antigenic dissociation.