Degradation of histamine and tyramine by Brevibacterium linens during surface ripening of Munster cheese

Red smear formation during fermentation of Munster cheese was started by using three different strains of Brevibacterium linens as surface inocula. The cheeses were produced with and without supplementation of histamine and tyramine. After smearing the cheese surface for the first time with B. linens viable counts of 10(7) CFU/g were detected. At the end of the logarithmic growth phase cell numbers increased to 10(10) CFU/g and remained constant during the whole ripening period. During a 4-week ripening period strains of B. linens reduced histamine and tyramine content by 55 to 70%. B. linens LTH 456 and LTH 3686 degraded histamine and tyramine in a phosphate buffer (pH 7) containing 0.54 M histamine and 0.58 M tyramine when incubated with agitation at 30 degrees C. B. linens LTH 3813 did not reveal any amine degradation activity in a buffer system. The pH on the cheese surface increased from 5 to 7, whereas it increased in the center only to 5.3 after a 3-week ripening period.