The influence of starter cultures on the lactic acid bacteria microbiota of Petrovac sausage

Petrovac sausage (Petrovska klobasa) is a high-quality fermented dry sausage produced traditionally in the municipality of Backi Petrovac (Vojvodina, Serbia). The product is characterised by specific and recognised texture, aroma and colour, produced without additives or preservatives. Lactic acid bacteria (LAB) microbiota plays an important role in production of the sausage. The aim of the paper is to monitor the changes in LAB during the production of Petrovac sausage. Samples of sausages were prepared without and with the addition of starter culture Staphylococcus xylosus as well as combined starter culture Lactiplantibacillus plantarum and S. xylosus, and produced at two different temperature ranges. A total number of 495 strains were isolated from 33 samples of Petrovac sausage during 120 days of production process. Characterisation of the isolates was performed by phenotypic tests, while molecular identification of the representative strains was done by 16S ribosomal DNA sequencing. The total number of LAB was about 8 log (Colony Forming Unit (CFU))/g in all samples, while the number of staphylococci was about 4 log CFU/g. Molecular identification confirmed that all isolates belonged to the following species: Levilactobacillus brevis, Leuconostoc mesenteroides, Lactiplantibacillus plantarum and Pediococcus pentosaceus. Lactobacilli and Leuconostoc spp. dominate the total LAB strains, while P. pentosaceus was isolated at the lowest frequency.