Production, isolation and purification of bacteriocins expressed by two strains of Neisseria meningitidis.
The systemic Neisseria meningitidis strain P241 and the healthy pharyngeal carrier strain BT878 produce bacteriocin-like substances during growth. A method has been devised for obtaining the active substances in solution. The activity was recovered by freeze-thaw extraction of dialyzed Todd-Hewitt agar medium into which the bacteriocins had diffused during growth of the producer strains. The bacteriocins were purified more than 50-fold by ammonium-sulphate precipitation and hydrophobic interaction chromatography. They are quite stable to heat and remain active 100% after 30 min at 100 degrees C. However, the protein nature of the bacteriocins has been confirmed by their sensitivity to alpha-chymotrypsin. Gel filtration indicated an Mr of 100-110 kDa, whereas SDS-polyacrylamide gel electrophoresis produced a common band by Coomassie staining corresponding to an Mr of 47-48 kDa, suggesting a dimer form of the active protein component.
Kaptein W. Wilhelmsen og Frues Institute of Medical Microbiology, University of Oslo, Rikshospitalet, Norway.
J
J
Allunans
M
M
Bjørås
E
E
Seeberg
K
K
Bøvre
D001430:Bacteriocins / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D006801:Humans; D008970:Molecular Weight; D009345:Neisseria meningitidis / Q000378:metabolism*
D001430:Bacteriocins