Identification of Lactic Acid Bacteria in Pork Meat and Pork Meat Products Using SDS-PAGE, 16S rRNA Gene Sequencing and MALDI-TOF Mass Spectrometry

Lactic acid bacteria (LAB) are major components of the microbial flora of packaged and cured meats and can contribute to spoilage. Bacteriological analyses of the pork meat and pork meat product samples were carried out to know the diversity of LAB across the samples. Thirty-one samples of raw pork meat, semi-processed pork meat and pork meat products were collected from four meat factories in Korea. A total of 216 LAB were isolated and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 16S rRNA gene sequencing followed by confirmation of results using matrix-assisted laser desorption ionization-time of flight mass spectrometry. Lactobacillus (Lb.) sakei was the most dominant LAB associated with all samples, regardless of the origin or packaging. The next predominant LAB were Lactococcus (Lc.) lactis and Pediococcus pentosaceus in raw samples, Lb. plantarum and Lb. brevis in semi-processed samples, and Weissella viridescens and Lc. lactis in product samples. Lb. plantarum, Lc. lactis and Lb. brevis were LAB found in all sample groups. Practical Applications Identification of lactic acid bacteria (LAB) in pork meat and pork meat products is fundamental to understanding the onset of spoilage. The results will reveal the prevalence of different species in different processing conditions and be helpful in order to analyze spoilage by LAB rapidly and accurately. The high LAB loads detected on pork meat indicated that strategies to reduce microbial load and improve food safety are needed.