28] Preparation of hemolysin from Aeromonas

Abstract

Publisher Summary This chapter describes the preparation of Hemolysin from Aeromonas hydrophila. A. hydrophila, a gram-negative bacterium of the family Vibrionaceae is ubiquitously found in nature and commonly isolated from cold- and warm-blooded animals, various waters and sewage, and may act as a primary human pathogen. It causes furunculosis and septicemia in fish. In contrast to most gram-negative organisms A. hydrophila produces several extracellular enzymes and toxins during growth—namely, hemolysins, enterotoxin, proteases, phospholipases, lipase, elastase, phosphatase, aminopeptidases, and ribonuclease. Hemolysin is produced during growth in various media, and released into the culture medium during the logarithmic growth phase. Unless otherway stated all operations were carried out at 4°. A precursor of hemolysin is detected in culture fluid during the logarithmic phase of growth. It is converted to mature toxin by proteolytic enzymes, hence very little precursor is present in the stationary phase. It is about 250 times less hemolytic than hemolysin and possibly nonhemolytic.