The Production of Histamine in Bacterial Cultures

Publisher Website
Google Scholar
Abstract
Using a simplified technic previously described (see preceding abstract) histamine production was detd. in cultures of 49 strains of bacteria, belonging to 14 species of 7 genera. These organisms all have their habitat in the intestinal tract. With the exception of Clostridium welchii, all of these organisms require free histidine for histamine formation. In a favorable medium, histamine production begins within 24 hours and continues rapidly for 4-5 days, after which the rate of production decreases. For most organisms, the optimal pH for histamine production is pH 5 to 5.5, and no histamine is produced at reactions more alkaline than pH 6.5. However, the histamine-forming strains of Aerobacter aerogenes will produce this amine at any pH between 5 and 8. The temp. of incubation markedly affects histamine formation. Temps. higher than 37[degree]C and lower than 26[degree] are usually unfavorable. Between these limits, the optimal temp. varies a great deal with different organisms. The yield of histamine is detd. also by the composition of the culture medium. Where only inorganic compounds of N are supplied, in addition to histidine, the yields of histamine are usually low, and some of the histidine may be converted to other imidazol bases. Addition of amino acids, such as asparagine and cysteine, or of peptone, or of egg yolk or meat infusion, increases histamine production. The nature of the added carbo-hydrate is also important, chiefly because of the effect of the pH of the culture.