COMPARISON OF DIFFERENT METHODS OF CELL-LYSIS AND PROTEIN MEASUREMENTS IN CLOSTRIDIUM-PERFRINGENS - APPLICATION TO THE CELL-VOLUME DETERMINATION

Four cell lysis methods (NaOH-SDS solubilization, French press treatme nt, sonication, mutanolysin treatment) and three methods of protein as says (Lowry, Bradford, Pierce) were studied for their applicability to determination of cell volume in Clostridium perfringens NCTC 8798 cel l suspensions. Protein contents were higher after a mechanical disrupt ion of the cells than with the other techniques of lysis. The lowest c oncentrations of protein were obtained with the Bradford procedure. Wi th each of the three protein assay methods, Clostridium perfringens NC TC 8798 protein cell contents were 45% to 58% of protein. Other factor s possibly involved in variations of the intracellular volume measurem ents were examined. A control of the level of protein concentration in the test sample and the type of silicone oil used for the centrifugat ion were of prime importance during sample preparation. Under our cond itions, an intracellular volume of 4 mu l/(mg of protein) was routinel y found for Clostridium perfringens NCTC 8798.