Related Experiment Videos
[Isolation and evaluation of properties of muramidase causing the lysis of group A streptococci]
Abstract:
Muramidase which actively lyses the cell walls of group A hemolytic streptococci has been isolated from the culture fluid of Actinomyces levoris by precipitation on ammonium sulfate, gel filtration on Sephadex G-25, ion exchange chromatography on DEAE cellulose and double electrofocusing. The enzyme thus obtained has shown its maximum activity at 40-50 degrees C. At 60 degrees C muramidase was completely inactivated. The enzyme has a wide range of optimum pH values: 5.0-9.5. The highest percentage of lysis of streptococcal cell walls has been observed in plycine-NaOH and potassium phosphate buffers at pH 8.0. Muramidase completely lysed Streptococcus pyogenes cells of different serological groups except enterococci (group D) and staphylococci. This sign allows to differentiate group D streptococcus from streptococci of other groups.
Insights
Researchers isolated muramidase from Actinomyces levoris, an enzyme that lyses group A hemolytic streptococci cell walls. This muramidase exhibits optimal activity between 40-50°C and a broad pH range of 5.0-9.5.
Area of Science:
- Microbiology
- Enzymology
- Biochemistry
Background:
- Group A hemolytic streptococci are significant human pathogens.
- Bacterial cell wall lysis is a key target for antimicrobial strategies.
- Muramidases are enzymes capable of degrading peptidoglycan in bacterial cell walls.
Purpose of the Study:
- To isolate and characterize muramidase from Actinomyces levoris.
- To investigate the lytic activity of the purified enzyme against streptococcal cell walls.
- To determine the optimal conditions for enzyme activity and its potential for differentiating streptococcal groups.
Main Methods:
- Isolation of muramidase using ammonium sulfate precipitation, Sephadex G-25 gel filtration, and DEAE cellulose ion exchange chromatography.
- Purification through double electrofocusing.
- Enzyme activity assays at varying temperatures and pH levels.
- Testing lytic activity against different serological groups of Streptococcus.
Main Results:
- Muramidase was successfully isolated and purified from Actinomyces levoris culture fluid.
- The enzyme demonstrated maximum activity at 40-50°C and was inactivated at 60°C.
- Optimal pH range for muramidase activity was found to be 5.0-9.5, with highest lysis at pH 8.0.
- Muramidase effectively lysed Streptococcus pyogenes cells from various serological groups, but not enterococci (group D) or staphylococci.
Conclusions:
- The isolated muramidase is effective in lysing group A hemolytic streptococci cell walls.
- The enzyme's distinct lytic profile, specifically its inability to lyse group D streptococci and staphylococci, can be utilized for differentiating these bacteria.
- This muramidase represents a potential tool in microbiology for bacterial identification and cell wall research.