Identification of lactic acid bacteria found in traditional Shalgam juice using 16S rRNA sequencing and evaluation of their probiotic potential in vitro

Abstract

This research focuses on the identification of lactic acid bacteria (LAB) isolated from traditionally produced Shalgam juices collected from different locations in Türkiye and the characterization of their probiotic potential in vitro. LAB isolates were identified by 16 S rRNA gene sequencing. The most common strains belonged to Pediococcus acidilactici (54.2%), Lacticaseibacillus sp. (18.8%), L. paracasei (8.3%) and Enterococcus faecalis (6.3%). According to the test results, LAB isolates survived after exposure to low pH (2.0) except Levilactobacillus brevis TS9 and P. acidilactici TS10. All isolates showed tolerance to bile salts (69.78%–147.84%), pepsin (50.10%–159.43%), pancreatin (46.64%–120.12%) and phenol (58.19%–121.84%) at various levels. The isolates E. faecalis TS2 and Lacticaseibacillus sp. TS3 were more resistant to the target microorganisms. The isolates E. faecalis TS2, L. paracasei TS7, P. acidilactici TS41, and P. acidilactici TS43 were highly resistant to the antibiotics. The hydrophobicity of the isolates toward xylene ranged from 2.32% to 58.56% and P. acidilactici TS42 showed a high hydrophobicity of 58.56%. The ability of auto-aggregation and co-aggregation varied from 3.59% to 23.67% and 0.85–29.37%, respectively. The isolates showing the best probiotic properties (Lacticaseibacillus sp. TS3, Lacticaseibacillus sp. TS11, and L. paracasei TS33) were tested for their ability to produce short-chain fatty acids. The acetate, butyrate and propionate production of the isolates varied between 4040 and 8135, 1025–1255 and 14620-17225 μg/mL, respectively. Butyrate production of the isolates were higher than the control group. These results indicated that LAB originated from Shalgam juice could be proposed as probiotic candidates for use in fermented foods.