EFFECTS OF PHYSICOCHEMICAL FACTORS INFLUENCING TYRAMINE PRODUCTION BYCARNOBACTERIUM DIVERGENS

Tyramine production by a strain of Carnobacterium divergens was tested in relation to different conditions of pH, temperature, glucose, oxyg en availability, potassium nitrate and sodium chloride content, using a combination of a Doehlert and Plackett-Burman experimental design. A second degree polynomial model was chosen to describe tyramine produc tion which was quantified by high performance liquid chromatography. M aximal tyramine production occurred during the stationary phase in aci dic conditions obtained by lon initial pH (<5) or addition of glucose (0.6%) to the medium. Production nas slower at 5 degrees C than at 23 degrees C and 10% sodium chloride inhibited this production. However, the formation of tyramine was not affected by the presence of potassiu m nitrate or oxygen availability.