Biosynthesis and ultrasonic degradation of bacterial poly(gamma-glutamic acid).

A study of the production of poly(gamma-glutamic acid) (PGGA) by Bacillus licheniformis NCIMB 11709 grown on medium E in shake flasks at 30 degrees C is reported. The enantiomeric composition of PGGA was found to be highly sensitive to the concentration of Mn++, especially when the ion is present in small amounts ( View Article and Find Full Text PDF

Complement resistance of capsulated strains of Aeromonas salmonicida.

The complement resistance of Aeromonas salmonicida strains grown under conditions promoting capsule formation was investigated using well characterized strains and their isogenic mutants. Complement resistance was previously studied using the same strains growing under non-capsulating conditions. The serum resistant strains were found to activate complement, but rapidly degrade C3b preventing productive formation of the lytic complex C5b-9.

Influence of the capsular layer on the virulence of Pasteurella piscicida for fish.

The influence of the capsule of Pasteurella piscicida on the cell surface properties of this microorganism as well as on the virulence and the capacity of the strains to grow in fish sera was examined. Although all the P. piscicida strains synthetized an additional exostructure in glucose-enriched-medium, only virulent strains constitutively synthetized capsule.

The role of the capsular polysaccharide of Aeromonas salmonicida in the adherence and invasion of fish cell lines.

The ability of several Aeromonas salmonicida strains grown under different conditions (capsulated and non-capsulated) to adhere to and invade two fish cell lines was compared. The level of adherence was slightly higher when the strains were grown under conditions promoting capsule formation than when the same strains were grown under conditions which did not promote capsule formation. However, the most significant difference among the wild-type strains grown under conditions promoting capsule formation was the ability to invade fish cell lines, which was significantly higher than when the same strains were grown under conditions which did not promote capsule formation.

The presence of capsular polysaccharide in mesophilic Aeromonas hydrophila serotypes O:11 and O:34.

Mesophilic Aeromonas hydrophila from serotypes O:11 and O:34 grown in a glucose-rich medium produce a capsule that can be seen under light and electron microscopy. The purified capsular polysaccharide has a composition qualitatively similar for strains O:11 and O:34, but quantitatively different. The capsular polysaccharides were immunogenic in rabbits, and did not cross-react with specific antibodies against either purified lipopolysaccharide from strains O:34 or O:11 or against the S-layer characteristic of strains from serotype O:11.