Characterization of Pediococcus acidilactici PFC69 and Lactococcus lactis PFC77 Bacteriocins and Their Antimicrobial Activities in Tarhana Fermentation

Abstract

Tarhana is a traditional cereal product fermented by lactic acid bacteria (LAB) and yeast strains that has gained special interest recently as an infant nutrition. Tarhana contains wheat flour, yogurt, and various vegetables that might create a microbiological toxicological risk, especially for Bacillus cereus and Staphylococcus aureus. In this study, characterization of the metabolites responsible for antibacterial activity of Pediococcus acidilactici PFC69 and Lactococcus lactis PFC77 strains obtained from tarhana was performed, and antibacterial effects were detected against B. cereus ATCC 11778 and S. aureus ATCC 29213 during the fermentation. A total of 12,800 AU/mL antibacterial activity was observed for the supernatants of the PFC69 and PFC77 strains that were found to be stable at high temperature and in low pH conditions and sensitive to proteases, suggesting the antimicrobial metabolite is a bacteriocin. These bacteriocins were further purified and their molecular sizes were determined as 4.5 and 3.5 kDa, respectively. Importantly, inoculation of PFC69 and PFC77 to tarhana dough significantly decreased B. cereus ATCC 11778 and S. aureus ATCC 29213 amounts from the fifth day of fermentation compared to the control dough samples. P. acidilactici PFC69 and L. lactis PFC77 strains were concluded as bioprotective cultures for tarhana and these strains were offered for other cereal-based fermentations.

Evaluation of inhibitory compounds produced by bacteria isolated from a hydrogen-producing bioreactor during the self-fermentation of wheat straw

“…Proteinaceous substances also play an essential antagonistic role, although less profound, for C. beijerinckii (Table 3; Figure 2), as evidenced by the reduction in antimicrobial activity when LAB cell-free supernatants of L. plantarum LB1, L. pentosus LB7, E. faecium F and P. acidilactici LB4 were treated with proteases. Similar results have been reported when secreted proteins from L. plantarum, L. pentosus, E. faecium and P. acidilactici were hydrolyzed with different proteolytic enzymes (Ghanbari et al, 2013;Kaya & Şimşek, 2020;Kemperman et al, 2003;Morales-Estrada et al, 2016;Pieniz et al, 2015;Ramakrishnan et al, 2012;Simova et al, 2009).…”

Genomic Insight into Pediococcus acidilactici HN9, a Potential Probiotic Strain Isolated from the Traditional Thai-Style Fermented Beef Nhang

“…Pediococcus , a genus of gram-positive lactic acid bacteria (LAB), is classified as part of the Lactobacillaceae family [ 1 ]. These bacteria, which are commonly found in fermented vegetables, meats, and dairy products, play an important physiological role in fermentation [ 2 , 3 , 4 ]. Several species of Pediococcus are used in the food industry, owing to their inhibitory effects on other microorganisms via antimicrobial peptide production [ 5 , 6 ].…”

“…In addition, there are many reports of bacteriocins produced by Pediococcus strains, including Pediocin F [ 7 ], Pediocin PA-1 [ 8 ], and Pediocin SA-1 [ 9 ]. Pediococcus acidilactici is a potent producer of bacteriocins that has been used in the food industry for many years [ 3 , 4 , 10 , 11 ]. Moreover, several studies have reported that P. acidilactici can inhibit the growth of pathogens during the fermentation process and food storage [ 4 , 6 , 12 , 13 ].…”

“…Pediococcus acidilactici is a potent producer of bacteriocins that has been used in the food industry for many years [3,4,10,11]. Moreover, several studies have reported that P. acidilactici can inhibit the growth of pathogens during the fermentation process and food storage [4,6,12,13].…”

The Comparison of the Microbiological Characteristics of Wet Dough and Dry Powder Tarhana’s and Evaluation of Possible Health Risks

“…Although there are studies examining the effects of different production techniques on tarhana properties, a limited number of studies examining tarhana in terms of microbiology have been carried out (Kivanc and Funda, 2017). Moreover, microbiological changes in the fermentation process and after drying of tarhana produced in the laboratory were discussed, and the total mesophilic aerobic bacteria (TMAB), total yeast and mold (TYM) and lactic acid bacteria (LAB) counts were examined in general (Erbaş et al, 2005;Karagozlu et al, 2008;Settanni et al, 2011;Donmez, 2015;Özel, 2015;Kivanc and Funda, 2017;Arslan-Tontul et al, 2018;Kaya and Şimşek, 2020). For this reason, TMAB, TYM, Escherichia coli (E. coli) and enterococci bacteria (EB) count of wet dough tarhana samples from Kastamonu city and dried powder tarhana samples were investigated and samples taken from TYM colonies cultured from wet dough tarhana were examined under an electron microscope.…”