In Vitro Characterization of Limosilactobacillus reuteri Lac Ib01 (OL468126.1) Isolated from Traditional Sheep Dry Sausage and Evaluation of the Activity of Arthrospira platensis or Phycocyanin on Its Growth-Promoting Ability

The positive impact of probiotic strains on human health is more evident than ever. To achieve the beneficial health effects and desirable functional properties of probiotics, sufficient numbers of these microorganisms must reach the intestinal tract with high survival rates. The purpose of this study was to identify and characterize a novel strain of Limosilactobacillus reuteri isolated from traditional sheep dry sausage and evaluate its growth-promoting ability with the addition of Arthrospira platensis or phycocyanin extract. In vitro experimental approaches were conducted to determine the physiological features of the candidate probiotic isolate, including biochemical identification, 16S rRNA gene sequencing, tolerance assays to acid and bile salts, antimicrobial activities, adherence ability, and antiproliferative assays. The effects of A. platensis or phycocyanin (0, 1, 5, and 8 mg/mL) on the growth of probiotic cultures were studied after 0, 24, 48, and 72 h. Our results showed that the isolated Limosilactobacillus reuteri (OL468126.1) possesses desirable characteristics as a probiotic candidate and can, therefore, be used as an ingredient in functional foods. Furthermore, A. platensis and phycocyanin extract have great potential for enhancing the growth and prolonging the stationary phase of isolated probiotics. Our findings showed that phycocyanin extract not only plays the role of a natural pigment but also acts as a growth promoter of probiotics.