Effect of nitrate and incubation conditions on the production of catalase and nitrate reductase by staphylococci

The objective of this work was to study the production of catalase and nitr ate reductase by staphylococci in order to understand their role in lipid o xidation during sausage manufacturing. Catalase and nitrate reductase were measured in resting cells and supernatants of staphylococci grown in differ ent conditions. All staphylococci (except S. warneri) synthetized nitrate r eductase. In static condition, the synthesis was maximal during exponential ,growth phase, whereas in shaking condition, the synthesis was maximal at t he beginning of stationary phase. The production of nitrate reductase was i ncreased in presence of nitrate, this effect was particularly important for the two S. carnosus strains which exhibited the highest activity. For all staphylococci, the production of catalase was maximal at the end of the exp onential growth phase. The lowest amount of catalase was produced by S. war neri and the highest by S. carnosus. Only S. xylosus 873 and S. saprophytic us 852 released high amounts of catalase in the supernatant growth. Staphyl ococci produced higher amounts of catalase in shaking conditions. Addition of nitrate in the growth media favoured the synthesis of catalase, with a p ronounced effect for S. carnosus. Nitrate also favoured the release of cata lase. (C) 1999 Elsevier Science B.V. All rights reserved.