Streptococcins of Indigenous Hemolytic Streptococci

Abstract

Human hemolytic streptococci were monitored for bacteriocinogenic activity against intra- and inter- generic bacteria. 20% of the isolates showed broad range bioactivity, but non of the producers was antagonistic against closely related streptococci. The bioctivity was resistant to lysozyme and lipase but sensitive to trypsin. The streptococcin preparation remained stable at 2–8 pH range, 100°C (for 10 min) and 80°C (for 120 min). Different preparations retained their bioactivity at -20°C for variable time (2 to 30 days). Streptococein titre was 28 arbitrary units (AU); whereas, lacuna percentage was 14.6. Temperature (40°C) mediated plasmid curing revealed the chromosomal location of the bacteriocinogenic determinants. The bacteriocin protein was found to be 16.6 Kd (by SDS-PAGE).

Key Words:

• Streptococci
• Streptococcin
• Bacteriocinogenic determinants
• Broad-range antagonism
• Lacuna
• Arbitrary unit (AU)
• SDS-PAGE