This 1960 study investigated how anionic detergents, particularly sodium dodecyl sulfate (SDS), disaggregate bacterial cell walls from six Gram-negative bacteria species. Isolated cell walls were exposed to SDS across various pH values (2-9), temperatures (18-53°C), and detergent concentrations. Turbidity measurements indicated nearly complete wall disaggregation, with maximum effects at pH 8. Alcohol sulfate detergents with 10-16 carbon alkyl chains were tested, showing peak activity with the C12 compound. The researchers found no evidence that disaggregation involved protein denaturation through sulfhydryl group liberation or disulfide bond disruption, as no free sulfhydryl groups were detected and p-chloromercuribenzoate offered no protection. Autolytic enzymes did not contribute to wall dissolution. Lecithin showed only temporary protective effects, suggesting weak surface adsorption rather than substantive protection. The results indicated that SDS interactions primarily target lipid, lipoprotein, and lipopolysaccharide components of the wall structure. The study supports a physico-chemical mechanism of disaggregation rather than enzymatic or protein-mediated destruction.

Key findings

• Sodium dodecyl sulfate completely disaggregates isolated cell walls of six Gram-negative bacterial species, with maximum activity at pH 8 and higher temperatures
• The disaggregating mechanism involves direct interaction with lipid and lipoprotein components rather than protein denaturation via sulfhydryl group disruption or disulfide bond cleavage
• Alcohol sulfate detergents with C12 alkyl chain length showed optimal lytic activity against Salmonella gallinarum walls
• Autolytic enzymes and lecithin protection do not significantly contribute to or prevent SDS-mediated wall disaggregation