Alternatives for nitrate and nitrite in fermented meat products: potential contribution of the nitric oxide synthase activity of coagulase-negative staphylococci

Background Nitrosomyoglobin, which is the cured colour of fermented meat products, results from the interaction between muscle-based myoglobin and nitric oxide (NO) [1]. NO originates from the addition of nitrate and/or nitrite as curing agents to the meat batter. During fermentation, nitrate is reduced into NO-yielding nitrite by coagulasenegative staphylococci (CNS), present in the meat or added as starter culture [2]. However, health concerns related to the consumption of cured meats are leading to research for alternatives to generate the cured colour. A yet poorly explored pathway could potentially be based on the action of nitric oxide synthase (NOS), which produces NO from arginine. Bacterial NOS activity has only been scantily described, particularly its potential presence in meat-related bacteria and its dependency on environmental conditions. Based on preliminary attempts [3], and because up to now none of the sequenced Lactobacillus species contain a NOS homologue [4], this study focused on meat-related CNS.