ABSTRACT

The purpose of this study was to determine frequency of occurrence of halotolerant and halophilic histamine-forming bacteria under laboratory conditions in salted herrings stored at 20°C for 2 months. The other aim was to isolate these bacteria both from herrings bought in a retail shop and examine the ability of decarboxylation of histidine by these microorganisms using Kamop’s method modified by the authors. The amount of histamine formed was determined by fluorometric method. The level of histamine in media containing homogenates of herrings was in a range from 5 to 1950 (j.g/100 ml of a nutrient medium. All isolated bacteria belong to halotolerant and halophilic strains and produce histamine both at 8% and 20% content of NaCl in a nutrient medium. The obtained results indicate that during storage of salted herrings at ambient temperature the increase of histamine content in their flesh can occur.