MICROBIAL CELL WALLS 



tion/3,14 decompression rupture/^ pressure cell disinte- 

 grator 16) 



2. Osmotic lysis 



3. Autolysis ^^ 



Of the three methods, mechanical disintegration is prefer- 

 able, and all of the major methods listed under (1) have 

 been used successfully in wall isolation. The method of 

 choice will depend on the particular organism, but it may 

 be worth emphasizing that of the mechanical procedures 

 tried disintegration by sound and supersound can lead to a 

 greater breakdown of the wall structure than that en- 

 countered with the other methods. ^^ Even the robust walls 

 from Staphylococcus aureus can be rendered nonsediment- 

 able by exposure in the 10-kc Raytheon for 30 to 60 min- 

 utes.i^ Marr and Cota-Robles ^o have also pointed out 

 that concomitant with the disruption and release of ribo- 

 somes and intracellular particles from Azotobacter vine- 

 landii there is a disintegration of the "envelope" structure. 

 These effects of sonic disintegration of wall, or envelope, 

 may account for the rather low yields of walls encountered 

 by some investigators. 



Disintegiation is generally performed under conditions 

 that minimize enzymic modification of the walls, and the 

 methods devised by Shockman, Kolb, and Toennies ^i and 

 Ribi, Perrine, List, Brown, and Goode ^^ have great ad- 

 vantages in that the temperature can be controlled accu- 

 rately during disruption. Many organisms contain en- 

 zymes capable of completely digesting their own cell walls. 

 Strange and Dark -^ had difficulty in obtaining wall prepara- 

 tions of Bacillus spp. free of cell-wall degrading enzymes. 

 Because of the risk of degrading the wall enzymically, lytic 

 and autolytic methods of cell disintegration are not recom- 

 mended. On the other hand, various enzymes have been 



