The osmotic and surface properties of marine luminous bacteria

✍ Scribed by Johnson, Frank H. ;Harvey, E. Newton

• Publisher: Wiley (John Wiley & Sons)
• Year: 1937
• Tongue: English
• Weight: 889 KB
• Volume: 9
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030090306

✦ Synopsis

When a large amount of pure distilled water is added to a sea water suspension of a marine luminous bacterium, the luminescence and motility cease arid the suspension becomes clearer and foa1ny.l The foaminess arid loss of luminescence do not occur in sucrose solution isotonic with sea water SO that these effects cannot be due to the diminution of salts in the suspeiisions diluted with water. Osmotic bacteriolysis (cytolysis), with the liberation of surface active substances and destruction of the cell appears to occur.

Hill ('29) studied this cytolysis of luminous bacteria in different sea water dilutions and came to the conclusion that the bacteria are surrounded by rather rigid membranes like the cellulose wall of plant cells. They do not swell freely as an erythrocyte does but rupture o r crack, liberating tlic cell contents a t a critical difference in osmotic pressure between cell and medium. The refractive index of the ruptured bacterial ghosts is about that of water so that optically the suspension clears. Different degrees of resistance will naturally occur in a bacterial population so that the per cent of cytolysis will depend on degree of dilution.

Luminous bacteria grow if culture tubes are inoculated from the diluted sea water but it is not possible to state a t present how many will grow (Korr, '35 b ) . *Made by evaporating filtered sea water at low temperature. The bacteria will live and grow in sea water to which 3% NaCl has been added.