Metabolic heterogeneity and techno-functional attributes of fermented foods-associated coagulase-negative staphylococci

Coagulase-negative staphylococci (CNS) are one of the most pervasive heterogeneous groups of bacteria which are used as starter/adjunct cultures to enhance the aroma and texture of fermented foods. The organoleptic characteristics of fermented foods rely on disparate metabolic attributes of CNS. Nitrate reductase production from CNS improves sensory characteristics of foods by converting nitrate into nitrite. These bacteria utilize arginine via arginine deiminase pathway in the cytosol, and thus, play effective role in the generation of colour of fermented foods. Coagulase-negative Staphylococcus spp. develop flavour in foods by fermenting carbohydrates, converting amino acids, inducing β-oxidation of lipids, and secreting esterases. Additionally, the characteristic flavour of foods depends on the proteolytic and lipolytic properties of CNS strains too. Coagulase-negative staphylococci strains have revealed exemplary functional or probiotic traits by showing tolerance to acidic pH and bile, depicting adhesion characteristics, producing exopolysaccharide, and secreting therapeutic bacteriocins. Unfortunately, some CNS strains have shown antibiotics resistance, enterotoxins secretions, biogenic amine productions, haemolytic activities, and biofilm formations, thereby indicated the utilization of CNS on strain-by-strain basis. This review sheds light not only on the metabolic heterogeneity and techno-functional traits but also the safety and pathogenic aspects of fermented foods-associated CNS strains.