INVESTIGATION OF THE ROLE OF SULFHYDRYL GROUPS IN BACTERIA IN RELATION TO THE GRAM STAIN

Fischer and Larose (1952a, b) proposed a chemical explanation of the gram positive and gram negative states. Essentially their concept is that the reduction of disulfide (S-) linkages to sulfhydryl (-SH) groups in intact wool and gram negative bacteria will convert these to a gram positive state. Reformation of disulfide linkages or other stable groups (such as CS-C) will restore these same materials to their original gram negative state. Alkalis or reducing agents would convert intact wool and all gram negative bacteria to a gram positive state, whereas acids and oxidizing agents would convert these materials to a gram negative state. Although Fischer and Larose state that the explanation of the chemistry of the gram reaction is probably not as simple as that given above, they strongly implied that these reactions are the essence of gram conversions. If this concept were correct then gram positive bacteria should have a higher sulfhydryl content than gram negative bacteria. This paper reports the results of quantitative sulfhydryl measurements made on gram positive and gram negative bacteria.