Biodiversity and characterization of gram-positive, catalase-positive cocci isolated from pastırma produced under different curing processes

Abstract

The aim of this study was to determine the effects of different curing temperatures (4 °C or 10 °C) and agents (KNO$_{3}$ or NaNO$_{2}$) on microbiological and physicochemical properties of pastirma and diversity of gram-positive, catalase-positive cocci (GCC$^{+}$) and also to investigate some technological properties of the strains. Four different groups of pastirma were produced applying different curing temperatures and agents. After production, $GCC^{+}$ isolated from pastirma were subjected to phenotypic and genotypic (16S rRNA sequencing) identification. Genotypically characterized strains were evaluated for their technological properties. In all groups, a$_{w}$ and pH were observed to be under 0.90 and over 5.5, respectively. In genotypic identification, 45 isolates were identified as Staphylococcus vitulinus, while other isolates identified were S. equorum (n = 15), S. saprophyticus (n = 15), and S. xylosus (n = 12). All of the strains could grow at different salt concentrations (8% and 15%) and temperatures (4 °C, 10 °C, and 37 °C). Four strains of S. saprophyticus showed strong lipolytic activity while nine strains of S. vitulinus had strong proteolytic activity. This study showed that different curing temperatures and agents are particularly effective on the microflora in pastirma; however, these factors do not cause a high diversity in $GCC^{+}$ in terms of species.