BIOCHEMICAL TESTS FOR THE SELECTION OF STAPHYLOCOCCUS-STRAINS AS POTENTIAL MEAT STARTER CULTURES

A fast screening procedure has been applied for the isolation of staph ylococcal strains with possible value as starter cultures in fermented meat products. Colonies isolated in MSA (mannitol-salt phenol red-aga r) from a naturally fermented spanish 'salchichon' were stabbed into K NO3-containing agar plates. Then, colonies showing very high and low n itrate reductase activity were selected and used in further biochemica l tests. All strains were identified as Staphylococcus xylosus, with t he exception of one Staphylococcus epidermidis isolate. In addition to the APIZYM(R) galleries, other activities were quantified, such as, n itrate reductase, catalase, proteases and lipases. High nitrate reduct ase was found in some of the strains. Lipase activity was found in dif ferent strains, and all of them had an interesting cell-bound proteina se activity when assayed against p-casein. Another study should be und ertaken to test these strains of S. xylosus for the production of ferm ented meat products, and their activities correlated to the developmen t of desirable physicochemical and organoleptic characteristics. (C) 1 996 Academic Press Limited