the increased histamine in the medium were determined
using HPLC. Results are shown in Table 3. Although all the
microorganisms studied produced histamine, their ability to
transform histidine into histamine varied. All three species
produced a high level of histamine during the first 24 hours.
Enterobacter agglomerans and Enterobacter cloacae were less
efficient than Morganella morganii in transforming histidine
into histamine under the conditions used in this study (Table 3).
Enterobacter agglomerans transformed only 5.1 to 5.8% of the
histidine contained in the medium (10,000 ppm) into histamine,
and Enterobacter cloacae transformed 4.4 to 5.2%. Morganella
morganii transformed 61.5 to 73.7% of the histidine into
histamine. The higher ability of some microorganisms to convert
histidine into histamine depends strongly on their enzymatic
activity and their ability to grow in different environmental
systems (EDMUNDS; EITENMILLER, 1975; KIM et al., 2002).