Abstract
Lactiplantibacillus plantarum, one of lactic acid bacteria (LAB), is found in various foods, including dairy products, meat, and vegetables, and most of these bacteria offer beneficial effects to humans and animals as potential probiotics with broad-spectrum antimicrobial activities. The aim of this study was evaluating the antibacterial efficacy of L. plantarum against some foodborne bacteria isolated from dairy products. This research involved 34 dairy products, including local and imported milk, cheese, and yogurt sold locally in Baghdad province, Iraq, during May 2022. For the isolation of L. plantarum, a special medium called MRS (de Man Rogosa and Sharpe) was applied. Colonies were purified and identified by routine bacteriological methods, Vitek2 system, and confirmed by the polymerase chain reaction (PCR) targeting the 16S rRNA gene followed by the amplicon sequencing. Other aerobic bacteria contaminating dairy products were also isolated onto sterile selective media specific for each microorganism, and the isolates were identified by routine diagnostics tests followed by verification with Vitek2 system. Then, the culture supernatant of L. plantarum was tested for its antagonistic activity toward foodborne bacteria by the use of agar well diffusion assay. The findings showed the isolation of 2 L. plantarum, 3 Pseudomonas aeruginosa, 4 Escherichia coli, one isolate of Bacillus subtilis, and another Staphylococcus hominis. The filtered supernatant of L. plantarum was significantly efficient in inhibiting the growth of the above bacteria. Each of E. coli and B. subtilis revealed zones of inhibition of 36 and 38 mm in diameter, respectively, while P. aeruginosa and S. hominis had inhibition zones diameters of 27 and 29 mm, respectively. This suggests that the L. plantarum supernatant possesses a broad-spectrum activity against foodborne bacteria. To conclude, locally made dairy products can hold different contaminating bacteria, which can be eliminated by using probiotics, such as L. plantarum, to avoid foodborne diseases onset.
Publisher
Baghdad University College of Veterinary Medicine
Subject
Management, Monitoring, Policy and Law,Geography, Planning and Development
Reference43 articles.
1. Liu B, Yang M, Qi B, Chen X, Su Z, Wan Y. Optimizing l-(+)-lactic acid production by thermophile Lactobacillus plantarum As. 1.3 using alternative nitrogen sources with response surface method. Biochem. Eng. J. 2010; 52(2): 212–219. DOI: 10.1016/j.bej.2010.08.013.
2. Zheng J, Wittouck S, Salvetti E, Franz C, Harris H, Mattarelli P, et al. A taxonomic note on the genus Lactobacillus: Description of 23 novel genera, emended description of the genus Lactobacillus beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae. Int. J. Syst. Evol. Microbiol. 2020;70(4):2782–858. DOI: 10.1099/ijsem.0.004107.
3. Behera S, Ray R, Zdolec N. Lactobacillus plantarum with functional properties: An approach to increase safety and shelf-life of fermented foods. BioMed. Res. Int. 2018; Article ID 9361614. DOI: 10.1155/2018/9361614.
4. Saito R, Sato N. Characterization of Lactiplantibacillus plantarum TO-A growth inhibition activity against pathogenic bacteria. J. Prob. Health. 2021;9(9): 253. Available at: https://www.longdom.org/open-access/characterization-of-lactiplantibacillus-plantarum-toa-growth-inhibition-activity-against-pathogenic-bacteria.pdf.
5. Rocchetti M, Russo P, Capozzi V, Drider D, Spano G, Fiocco D. Bioprospecting antimicrobials from Lactiplantibacillus plantarum: Key factors underlying its probiotic action. Int. J. Mol. Sci. 2021; 22(21):12076. DOI: 10.3390/ijms222112076.