Homologous and heterologous reactions of bacteriophages phi 41 and phi 12 on the capsular polysaccharides from Klebsiella K41 and K12.

The structures of the capsular polysaccharides from Klebsiella K41 and K12 are very similar and differ only in the lateral, terminal group of their respective repeating units. The bacteriophages phi 41 and phi 12 are shown to hydrolyze the same alpha-galactopyranosyl bond in each of the polysaccharides, giving rise to an oligosaccharide characteristic of the starting polysaccharide, irrespective of the phage employed. The presence of the uronic acid function is essential for the phages to be active, but the carboxyl group of the pyruvic acetal in K12 does not appear to play a role in the recognition process.