Biogenic amine formation and oxidation by Staphylococcus xylosus strains from artisanal fermented sausages.

Fifty strains of Staph. xylosus, isolated from artisanal fermented sausages in Southern Italy (Lucania region) were tested to verify their potential to produce or degrade biogenic amines. Twenty-six strains analysed were not able to form amines, but seven had the potential to produce spermine and/or spermidine and, at lower levels, tryptamine and tyramine. By contrast, about 80% of the strains that did not possess amino acid decarboxylase activity, exhibited an ability to degrade histamine. The greatest histamine-oxidase activity was present in the strains S81 (100% degradation), S206 (93%), S79 (68%) and S90 (53%). The strain S142 exhibited a remarkably high potential to oxidase tyramine and histamine, reducing the initial concentrations by 63 and 47%, respectively.