Foodborne disease caused by pathogenic bacteria is one of main concerns in food industry. To supply safe food products, chemical and thermal intervention technologies have been widely applied in food industry, however these treatments have their own limitations. The concept of biopreservation has recently received increased attention in response to industrial and consumer demands. The biopreservation technologies mainly include bacteriocin, bacteriophage, bacteriophage-encoded enzymes, and endolysins. Among them, bacteriocins have been widely recognized as a main biopreservative and have also been most studied. Bacteriocins, mainly consisting of antibacterial peptides, may have bactericidal or bacteriostatic effect which could prolong the shelf-life as well as maintain safety of foods. This review article offers a brief research trend about bacteriocins, focusing on microbial food safety. The antimicrobial mechanism of bacteriocins has been discussed and some efforts to inactivate foodborne pathogens have been analyzed in this review article. The challenges facing the application of bacteriocins have also been evaluated. Thus, this review will provide insights for researchers working in bacteriocin as well as industry personnel looking for a new method for fighting foodborne pathogens.

The association of lactic acid bacteria in human health has been investigated from early 1900s. The term of probiotics was defined in 1953 and various strains (Lactobacillus, Bifidobacterium, Streptococcus etc) have been isolating with diverse beneficial effects on human health. Over the century, the concept of traditional probiotics was based on observation of natural properties to restore healthy condition within different human ecosystems (intestine, skin etc) following by development of processing optimization for the stability of bacteria. Nowadays, the aim of probiotics for human health has been moving from gut stabilization towards expanded concept of pharmabiotics like as controlling disease (e.g. obesity, immune system, psychiatric stabilization etc). Along with the expansion, scientists and industry still remained to investigate reliability of efficacy by consumption of probiotics. In recent, probiotics and bacteriophage cocktails have been commercialized in the US market. The cocktails consist of several probiotic strains with four phages targeting pathogenic E. coli. The phages induce reduction of population in E.coli and Clostridium perfringens while prevalence of Eubacterium increased in a gut to 4–5 times prior to consumption. Also, immunological stabilization was observed by consumption ‘probiotics with phage’. Now, the probiotic R&D is moving towards pharmabiotics, and additional technologies in next-generation probiotics and prebiotics are actively investigating worldwide.

In this study, thirty-eight lactic acid bacteria (LAB) strains were isolated from Kimchi (Korean traditional fermented food) and screened for probiotic characterization in a series of in vitro tests, including resistance to low pH, tolerance to bile salts, hydrophobicity, antibiotic resistance and antioxidant activity. Firstly, twenty-two strains displayed survival in acid and bile passage conditions. Secondly, the strains KCCP 11349 and KCCP 11356 were observed to have high cell surface hydrophobicity with 63.9 and 98.8 %, respectively. Functionality of these potential probiotic isolates was supported by their antioxidant activity. Altogether, the strain KCCP 11349 showed characteristics similar to or even better than reference strain Lactobacillus rhamnosus GG. Finally, 16S rRNA gene sequencing was conducted to identify potential probiotic strains and KCCP 11349 was identified as Lactobacillus plantarum subsp. plantarum.

Whey is a major by-product of cheese manufacture and contains many valuable constituents, such as β-lactoglobulin, lactoferrin and immunoglobulin. The current study determined the anti-biofilm activity of bioconversion of whey by Lactobacillus plantarum (LP-W), L. rhamnosus GG (LR-W), L. brevis (LB-W) and Enterococcus faecium (EF-W) against foodborne pathogenic bacteria, Escherichia coli O157:H7 and Listeria monocytogenes. When the foodborne pathogenic bacteria were co-incubated with LP-W, LR-W, LB-W or EF-W, biofilms by E. coli O157:H7 and L. monocytogenes were significantly reduced by all bioconversion of whey. Moreover, LP-W, LR-W, LB-W and EF-W also dramatically reduced pre-formed biofilm by E. coli O157:H7 and L. monocytogenes, suggesting that the bioconversion of whey effectively suppress the development and disruption of biofilm by foodborne pathogenic bacteria. Furthermore, in order to determine the growth kinetics of E. coli O157 and L. monocytogenes planktonic cells in the presence the bioconversion of whey, LP-W, LR-W, LB-W and EF-W did not significantly inhibited the growth of foodborne pathogenic bacteria, implying that the bioconversion of whey reduces the biofilm without the decrease of bacterial growth. Taken together, these results suggest that bioconversion of whey by lactic acid bacteria could be a promising agent for the reduction of microbial biofilm.

In this study, we investigated culturable bacterial abundance in various crops. Total culturable aerobic bacteria in tomato plants were enumerated on NA and it showed that the amounts of viable bacterial cells were changed among the different parts of the plants (roots, stems, and fruits), ranging between log 1 and 4 per g sample. To investigate the bacterial abundance dynamics in different crops, culturable aerobic bacterial cell numbers were enumerated on NA and compared between the samples (tomato fruit, sesame leaf, and green onion) harvested freshly from one field trial (Yangsan, Korea). In this trial, the number of total culturable aerobic bacteria of the samples were 8 times higher in sesame leaves and green onions compared to the tomato fruits in the field. Interestingly, culturable aerobic bacteria on MRS were only found in sesame leaves, whereas lactic acid bacteria were not detected in tomato fruit and green onion samples in this field. We also found that the field location (Yangsan, Gangneung, or Busan) influenced the number of culturable aerobic bacteria on the surface of the crops. Tomato samples freshly harvested from the different field locations were tested and showed that the amounts of culturable aerobic bacteria on NA and MRS agar were significantly different based on the field locations of the samples. Finally, lactic acid bacteria were isolated from all the tomato and sesame leaf samples used in this study, showing 20 and 28 morphological diversity. With these isolates, we will be able to conduct further biological and functional investigation to develop a new probiotic strain originated from the crops in Korea.