Related Experiment Video
Updated: Jun 28, 2026

Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria
Published on: September 17, 2013
Separation and characterization of enterotoxin and two haemolysins from Aeromonas hydrophila
Abstract:
Aeromonas hydrophila produces two haemolysins, now designated alpha- and beta-haemolysin (formerly aerolysin or cytotoxic protein), and one enterotoxin. These toxins were separated and purified by isoelectric focusing and gel chromatography. Alpha- and beta-haemolysin differ with regard to prerequisites for their elaboration, such as selection of A. hydrophila strains and temperature and time for cultivation. The nature of their lytic effects on erythrocytes and toxic effects on tissue culture cells differs significantly. Alpha- but not beta-haemolysin was inactivated by reducing agents and activated by oxygen, while beta-haemolysin was more resistant than alpha-haemolysin to proteolytic enzymes but was inactivated by crude gangliosides. When separated from the two haemolysins, the enterotoxin gave positive reactions in the rabbit intestinal loop test, the rabbit skin and the adrenal Y1 cell test, though the sensitivity of the Y1 cell was low as compared with cholera toxin and E. coli LT toxin. No cytotoxic effects were obtained in HeLa cells.
More Related Videos
06:15Evaluating Virulence and Pathogenesis of Aeromonas Infection in a Caenorhabditis elegans Model
Published on: December 20, 2018
10:24Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii
Published on: April 10, 2020
Related Concept Videos
Formation of Lipopolysaccharides
Bacterial Toxins
Bacterial Gastroenteritis