Glycogen, the preferred energy source for extracellular protein formation and growth of Aeromonas salmonicida

A study was made of the effect of supplementing a rich 3% (w/v) tryptone soya broth (TSB) medium and a poorer 1.7% (w/v) tryptone-based medium with glucose, maltose and glycogen, as carbon sources, on growth and exoprotein formation by Aeromonas salmonicida. In TSB, glucose inhibited growth and repressed exoprotein formation whilst maltose and glycogen had little effect, up to 20 h, when compared with an unsupplemented control. By contrast, in the poorer medium, over a 24-h incubation period, growth was stimulated three-fold by glycogen, and whilst exoprotein formation was low in comparison with that observed in TSB, the greatest production was observed in the presence of glycogen. Extracellular alpha-amylase was measured in the tryptone medium in the presence of the three carbon sources and the highest level, produced in the presence of glycogen, was 1.6 times that with added maltose whilst none was detectable with glucose present. This pattern was repeated in the case of the maltose-inducible porin, LamB, of the outer membrane.

[1]  S. Dodsworth,et al.  Molecular cloning and nucleotide sequence analysis of the maltose-inducible porin gene of Aeromonas salmonicida. , 1993, FEMS microbiology letters.

[2]  J. Melling,et al.  Envelope structure and the development of new vaccines. , 1993, The Journal of applied bacteriology.

[3]  C. Frasch,et al.  Expression of Neisseria meningitidis iron-regulated outer membrane proteins, including a 70-kilodalton transferrin receptor, and their potential for use as vaccines , 1990, Infection and immunity.

[4]  G. Coleman,et al.  Identification of major common extracellular proteins secreted by Aeromonas salmonicida strains isolated from diseased fish , 1987, Applied and environmental microbiology.

[5]  T. Aoki,et al.  The outer membrane proteins of the fish pathogens Aeromonas hydrophila, Aeromonas salmonicida and Edwardsiella tarda , 1985 .

[6]  A. Danchin,et al.  Role of cyclic AMP in regulatory mechanisms in bacteria , 1980 .

[7]  F. Neidhardt,et al.  Regulation of lac Operon Expression: Reappraisal of the Theory of Catabolite Repression , 1978, Journal of bacteriology.

[8]  U. K. Laemmli,et al.  Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4 , 1970, Nature.

[9]  G. Coleman,et al.  The combined effect of isolated Aeromonas salmonicida protease and haemolysin on Atlantic salmon, Salmo salar L., compared with that of a total extracellular products preparation , 1988 .

[10]  G. Coleman,et al.  A comparison of the distribution of extracellular proteins produced by the protease-secreting organism Aeromonas salmonicida during aerobic and anaerobic growth. , 1986, Annales de l'Institut Pasteur. Microbiologie.