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Lactic acid bacteria biofilms can be used to reduce foodborne pathogen contamination in the food industry. However, studies on growth inhibition of foodborne pathogens by inducing biofilm formation of antagonistic microorganisms on abiotic surfaces are rare. We developed a desiccation-tolerant antimicrobial probiotic biofilm. Lactobacillus sakei M129-1 and Pediococcus pentosaceus M132-2 isolated from fermented Korean foods were found to exhibit broad-spectrum antibacterial activity against Bacillus cereus, Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes, and Salmonella enterica. Their biofilm levels were significantly (p < 0.05) higher on stainless steel than on polyethylene or ceramic. Biofilms of both isolates showed significantly (p < 0.05) enhanced resistance against desiccation (exposure to 43% atmospheric relative humidity) as compared with the isolates not in the biofilm form. The antimicrobial activity of the isolates was sustained in dried biofilms on stainless steel surface; the initial number of foodborne pathogens (average 7.0 log CFU/mL), inoculated on stainless steel chips containing L. sakei M129-1 or P. pentosaceus M132-2 biofilm decreased to less than 1.0 log CFU within 48 h. The lactic acid bacteria antibacterial biofilms developed in this study may be applied to desiccated environmental surfaces in food-related environments to improve microbiological food safety.

Geographical origin and authenticity are the two crucial factors that propel overall cheese perception in terms of quality and price; therefore, they are of great importance to consumers and commercial cheese producers. Herein, we demonstrate a rapid, accurate method for discrimination of domestic and import mozzarella cheeses in the Republic of Korea by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The protein profiles’ data aided by multivariate statistical analysis successfully differentiated farmstead and import mozzarella cheeses according to their geographical location of origin. A similar investigation within domestic samples (farmsteads/companies) also showed clear discrimination regarding the producer. Using the biomarker discovery tool, we identified seven distinct proteins, of which two (m/z 7407.8 and 11,416.6) were specific in farmstead cheeses, acting as potential markers to ensure authentication and traceability. The outcome of this study can be a good resource in building a database for Korean domestic cheeses. This study also emphasizes the combined utility of MALDI-TOF MS and multivariate analysis in preventing fraudulent practices, thereby ensuring market protection for Korean farmstead cheeses.

The study describes the effects of administration of Queso Blanco cheese containing Bifidobacterium longum on the fecal microbiota, metabolite and serum cytokine in healthy beagle dogs. Twelve healthy beagle dogs were randomly divided in three groups of four dogs each:a control group, not fed with any cheese, and groups fed with Queso Blanco cheese with B. longum KACC 91563 (QCB) or without B. longum (QC) for 8 weeks. Fecal microbiota was analyzed using a culture-based method and 16s rRNA gene sequencing. Serum cytokine levels, activation of natural killer cells, and proliferation of peripheral blood mononuclear cells were determined. SPME-GC-MS method was used to determine the concentrations of short chain fatty acids and indole in dog feces. Administration of QCB for 4 weeks significantly increased the Bifidobacterium. QCB supplementation for 8 weeks reduceds Enterobacteriaceae and Clostridium perfringens (p 0.05). The abundance of Fusobacterium, Blautia and Collinesella in QCB group were reduced as compared with the control group. Serum TNF-α and IL-6 levels at 8 weeks significantly increased in QCB group as compared with QC group. There was no change in the concentrations of total short chain fatty acids by B. longum at 0 and 4 weeks. At week 8, the acetic acid, propionic acid and butyric acid of the QCB and QC groups were significantly decreased compared to the control group. In conclusion, our results demonstrate that administration of QCB had positive effects on fecal microbiota and immune response in beagle dogs. We suggest that Queso Blanco cheese containing B. longum KACC 91563 could be used as a functional food for companion animals.

This study was performed to analyze the distribution and antimicrobial resistance of pathogenic microorganisms isolated from the carcass and environments of chicken processing plant located in Gyeonggi province from October to November in 2010. Chicken slaughterhouse was visited 3 times and totally 40 samples were collected from chicken carcass before and after washing (n

This report outlines the development of a rapid, simple, and sensitive detection system for pathogenic bacteria using a capillary electrophoresis-based, single strand conformation polymorphism (CE-SSCP) combined with PCR. We demonstrate that this method, used with primers targeting the V4 region of the16S rRNA gene, is capable of the simultaneous detection of 10 microbes that could be associated with foodborne illness, caused by animal-derived foods: Salmonella enterica, Listeria monocytogenes, Escherichia coli O157:H7, Campylobacter jejuni, Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, Yersinia enterocolitica, Vibrio parahaemolyticus, and Enterobacter sakazakii. The traditional detection techniques are time-consuming and labor-intensive, due to the necessary task of separate cultivation of each target species. As such, the CE-SSCP-PCR method, that we have developed, has the potential to diagnose pathogens rapidly, unlike the traditional technique, in order to prevent foodborne illness in a much more efficient manner.

The aim of this study was to screen lactic acid bacteria for the fermentation of garlic and to assess the increase in inhibitory activity of garlic fermented against antibiotic-resistant pathogens for use as an animal feed supplement. We screened 45 strains of lactobacillus for the fermentation of garlic. Of these strains, 23 showed similar growth rates with or without allicin. Cultures of the 23 strains were mixed with an equivalent amount of garlic juice and incubated overnight at 37°C. The three strains with the lowest pH values were Lactobacillus paracasei KCTC 3169, L5 strain, and L. reuteri SW. Garlic juice fermented by the L5 strain more strongly inhibited antibiotic-resistant pathogenic bacteria than L. paracasei KCTC 3169, L. reuteri SW, or garlic juice itself. By examining carbohydrate utilization, morphologic properties and 16S rRNA gene sequences, we identified the L5 strain as Pediococcus pentosaceus and deposited it in the name of P pentosaceus KACC 91419 into the Korea Agricultural Culture Collection. To identify the antimicrobial compound from the garlic filtrate fermented by P pentosaceus KACC 91419, we fractionated P. pentosaceus KACC 91419 culture on a C 18 column and checked the antimicrobial activity of fractions A6 to A10. Only fraction A9 showed inhibitory activity on Staphylococcus aureus. Comparing the mass spectra of the fractions with and without antimicrobial activity, we observed a single dominant product ion (m/z 157.99) from the fraction showing antimicrobial activity. Its molecular mass (157.99) was 2 atomic mass units less than that of allicin (162.02). This suggests that allicin might be converted to its derivative, which has antimicrobial activity, during fermentation by P pentosaceus KACC 91419.

Staphylococcus aureus is an important human pathogen responsible for life-threatening septicemia, endocarditis, and toxic shock syndrome. Although positive (MRSA; ATCC 33591) and negative (MSSA; ATCC 25923) control strains have been used for various pathogenesis or assay studies, little is known about the genomic structure of the strains, and there has been little genome-wide expression analysis. Phylogenetic analyses revealed that ATCC 33591 and ATCC 25923 are the most genetically diverse strains of the 15 S. aureus genomes studied. Microarray analysis showed that the most significantly upregulated group of MRSA genes was the transport group, which includes ATP-binding cassette (ABC) transporters, the two-component system, and the phosphotransferase system. Analysis of the KEGG pathway showed that ABC transporters and the two-component system were the most significantly altered in MRSA. Transcriptional profiling showed a clear difference in gene expression between MRSA and MSSA due to the great genetic distance between the two control strains. Therefore, we suggest that use of the two control strains in comparative genomics or transcriptomics studies would facilitate the identification of major genes for drug resistance in S. aureus.

The aim of this study was to develop a new starter for fermented milk. The approach started with 103 acid-producing isolates from Kimchi, a type of spiced, fermented cabbage and then PCR screening was used to identify 72 Lactobacillus strains. The ability to inhibit the growth of food-borne human pathogens (Escherichia coli, Salmonella enteritidis, Staphylococcus aureus) of these strains were measured, using the paper disk method. Among them, one bacterium (LHB55) that showed a strong antibacterial activity against food-borne human pathogens was identified and further characterized, using 16S rDNA sequencing and API 50CHL system. Because this isolate was identified as L. plantarum, it was named as L. plantarum LHB55. The yogurt produced using commercial LAB with L. plantarum LHB55 did not display properties that are microbially or physico-chemically different from the control group, which suggests that L. plantarum LHB55 can be used as a useful starter for yogurt containing high antibacterial activity. We think that identifying effective starter strains enabling further development of fermented milk that can deliver better health benefits such as antimicrobial properties is of high significance, and thus our effort in this type of approach will continue. (Key words : Kimchi, Lactic acid bacteria, Lactobacillus plantarum, Antibacterial activity, Yogurt)

The aim of our study was to develop a new starter culture for fermented milk. Polymerase chain reaction screening of 103 acid-producing isolates from Kimchi identified 72 Lactobacillus strains. The ability of the strains to inhibit the growth of the food-borne human pathogens (Escherichia coli, Salmonella Enteritidis, Staphylococcus aureus) was measured, using a conventional paper disk method. Among the 72 strains, strain LHC52 displayed potent antagonistic activity. Use of 16S rDNA sequencing and the API 50CHL system identified the strain as Lactobacillus plantarum and it was designated L. plantarum LHC52. Biochemical analyses revealed especially high antibacterial activity against E. coli. Yogurt produced using L. plantarum LHC52 did not show different microbiological and physicochemical properties compared to conventionally-prepared yogurt, implicating L. plantarum LHC52 as a useful, potently antibacterial starter culture for yogurt preparation.

The lactase activities of nine species of lactic acid bacteria were compared using the chromogenic substrate, . Streptococcus thermophilus KACC 91147 had the highest lactase activity among a total of thirty strains of Lactobacillus and S. thermophilus tested, including commercial strains. S. thermophilus KACC 91147 released of galactose in treated milk A () and in treated milk B ( milk) over 2 hours. In milk tolerance tests, the blood glucose level (BGL) of 6 volunteers (2 males and 4 females) clinically diagnosed as lactose intolerant increased 3.0 mg/dl after drinking milk A, but a significant (p was found after drinking milk B. This result suggests that the addition of S. thermophilus KACC 91147 cells into milk aids the digestion of lactose in milk and ameliorates the symptoms of lactose-intolerant individuals due to the activity of lactase from the lactic streptococci.

Poultry contamination can be largely attributed to the presence of chicken feces during the production process. Fecal contamination is often found in raw chicken products sold for human consumption. Quantitative analysis of the fecal microbial community of chickens using next-generation sequencing techniques is the focus of this study. Fecal samples were collected from 30 broiler chickens at two time points: days 1 and 35 of development. 454 pyrosequencing was conducted on 16S rRNA extracted from each sample, and microbial population dynamics were investigated using various automated bioinformatics pipelines. Diversity of the microbial community at the genus level increased during the 5-week growth period. Despite this growth, only a few dominant bacteria groups (over 80%) were identified in each fecal sample, with most groups being unique and only a few were shared between samples. Population analysis at the genus level showed that microbial diversity increased with chicken growth and development. Classification and phylogenetic analysis of highly represented microbes (over 1%) clearly showed high levels of sequence similarity between groups such as Firmicutes and Proteobacteria. These results suggest that the chicken fecal excreted microbiome is a dynamic system with a differentiated population structure that harbors a highly restricted number of higher taxa.

Lactic acid bacteria were isolated from silage, which produce high level of hydrogen peroxide in cell culture supernatant. The 16S rDNA sequences of the isolate matched perfectly with that of Lactobacillus fermentum (99.9%), examined by a 16S rDNA gene sequence analysis and similarity search using the GenBank database, thus named L. fermentum CS12-1. L. fermentum CS12-1 showed resistance to low pH and bile acid. The production of hydrogen peroxide by L. fermentum CS12-1 was confirmed by catalase treatment and high-performance liquid chromatography. L. fermentum CS12-1 accumulated hydrogen peroxide in culture broth as cells grew, and the highest concentration of hydrogen peroxide reached 3.5 mM at the late stationary growth phase. The cell-free supernatant of L. fermentum CS12-1 both before and after neutralization inhibited the growth of enterotoxigenic Escherichia coli K88 that causes diarrhea in piglets. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 1 : 90-95)

A extracellular cellulase producing bacterium was isolated from cow feces, and was identified to be Bacillus licheniformis on the basis of morphological and biochemical properties as well as the composition of cellular fatty acids composition (FAME). CMCase, FPase and avicelase activities of the isolates cultured in CMC media at 37°C for 24 hrs were 1.65 U/ml, 0.13 U/ml and 0.18 U/ml, respectively. However, β-glucosidase activity was not detected. The optimum pH and temperature for induction of the enzyme were 7.5 and 50°C. The maximum CMCase activity was observed at pH 7.5 and 75°C. Zymogram analysis for crude supernatant showed four major bands CMC-SDS-PAGE. By adding 0.1% DMP (Developed Microbial Product) -comp including B. licheniformis NLRI X-33, microbial product, to swine manure composting pile, the gab of composting temperature within the pile in DMP-comp and control was 23°C and 34°C, respectively, during the initial 23 day composting periods. Coliforms were not found in the swine + sawdust sampl...

This study was carried out to screen yeasts effective in reducing odor from pig feces. Three isolates from soil and compost sources were selected to treat pig feces. On the basis of morphological and biochemical characteristics, one isolate from compost was Candida rugosa, and two isolates from soil were Candida rugosa and Candida maris. These isolates showed deodorizing activity by reducing the concentration of NH3 and R-NH2. Volatile fatty acids (VFA) are the specific malodorous compounds of pig feces, and the Candida maris from soil showed a 100% reduction of butyric, iso-butyric, and iso-valeric acid in 10% pig slurry medium. However, the Candida rugosa from compost showed a 100% reduction of butyric and iso-butyric acid while that from soil showed a 100% reduction of propionic, butyric acid and iso-valeric acid in the medium. Also, these yeasts were effective in reducing NH4-N, soluble-N, and biological oxygen demand (BOD). (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 9 : 1286-1290)

Lactic acid bacteria were isolated from piglets and chicken and characterized. Lactic acid bacteria showing resistance to low pH and bile, adhesion to intestinal epithelium cells, and the inhibition of Escherichia coli and Salmonella spp. were identified as Lactobacillus acidophilus. L. acidophilus PF01 survived for 2 h in MRS broth adjusted to pH 2. L. acidophilus CF07 was less resistant than L. acidophilus PF01 to pH 2, but survived at pH 2.5 for 2 h. Both of isolates were able to grow in MRS broth containing 0.3% (w/v) bile, with L. acidophilus CF07 being more tolerant to bile than L. acidophilus PF01. L. acidophilus PF01 and CF07 adhered specifically to the duodenal and jejunal epithelium cells of piglet, and the cecal and duodenal epithelium cells of chicken, respectively. Both of isolates did not adhere to the epithelium cells of the various animal intestines from which they were isolated. When L. acidophilus was cultured with E. coli and Salmonella spp. in MRS broth, MRS broth containing 2% skim milk powder or modified tryptic soy broth at 37°C, L. acidophilus PF01 and CF07 inhibited the growths of E. coli K88 and K99, and S. enteritidis and S. typhimurium, respectively. Both of isolates were found to possess the essential characteristics of probiotic lactic acid bacteria for piglet and chicken. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 12 :1790-1797)

Background The incidence of food allergies has increased dramatically during the last decade. Recently, probiotics have been studied for the prevention and treatment of allergic disease. Objective We examined whether Bifidobacterium longum KACC 91563 and Enterococcus faecalis KACC 91532 have the capacity to suppress food allergies. Methods B longum KACC 91563 and E faecalis KACC 91532 were administered to BALB/c wild-type mice, in which food allergy was induced by using ovalbumin and alum. Food allergy symptoms and various immune responses were assessed. Results B longum KACC 91563, but not E faecalis KACC 91532, alleviated food allergy symptoms. Extracellular vesicles of B longum KACC 91563 bound specifically to mast cells and induced apoptosis without affecting T-cell immune responses. Furthermore, injection of family 5 extracellular solute-binding protein, a main component of extracellular vesicles, into mice markedly reduced the occurrence of diarrhea in a mouse food allergy model. Conclusion B longum KACC 91563 induces apoptosis of mast cells specifically and alleviates food allergy symptoms. Accordingly, B longum KACC 91563 and family 5 extracellular solute-binding protein exhibit potential as therapeutic approaches for food allergies.

Using a newly constructed de novo assembly pipeline, finished genome level assembly had been conducted for the probiotic candidate strain E. faecalis KACC 91532 isolated from a stool samples of Korean neonates. Our gene prediction identified 3,061 genes in the assembled genome of the strain. Among these, nine genes were specific only for the E. faecalis KACC 91532, compared with all of the four known reference genomes (EF62, D32, V583, OG1RF). We identified genes related to phenotypic characters and detected E. faecalis KACC 91532-specific evolutionarily accelerated genes using dN/dS analysis. From these results, we found the potential risk of KACC 91532 as a useful probiotic strain and identified some candidate genetic variations that could affect the function of enzymes.

Lactobacillus salivarius is a well-known lactic acid bacterium to which increasing attention has been paid recently for use as probiotics for humans and animals. L. salivarius NIAS840 was first isolated from broiler chicken feces, displaying antimicrobial activities against multidrug-resistant Staphylococcus aureus and Salmonella enterica serovar Typhimurium. Here, we report the genome sequence of L. salivarius NIAS840 (2,046,557 bp) including a small plasmid and two megaplasmids.

Lactobacillus johnsonii PF01, an autochthonous bacterium of the gastrointestinal tract, was isolated from a fecal sample from a piglet. The strain adhered specifically to the duodenal and jejunal epithelial cells of the piglet and had high bile resistance activity. Here we report the genomic sequence of L. johnsonii PF01.

Bifidobacterium longum strains predominate in the colonic microbiota of breast-fed infants. Here we report the complete genome sequence of B. longum subsp. longum KACC 91563, isolated from feces of neonates. A single circular chromosome of 2,385,301 bp contains 1,980 protein-coding genes, 56 tRNA genes, and 3 rRNA operons.

Members of the Bacillus cereus group were isolated from rice products by centrifugation-plating and conventional spread-plating methods. Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) results showed broad diversity among the strains and revealed some associations among isolates from raw and cooked rice samples, at the genotypic level. A comparatively greater diversity among strains was observed in isolates from raw rice than those from cooked rice and, generally, the RAPD profiles of isolates from raw and cooked rice were different, with only a few of them common to both types of rice. The toxigenic potential of the isolates was also determined by molecular and immunoassay analyses. The results revealed that most isolates from the B. cereus group were potentially or actually toxigenic, and some isolates could produce both diarrhoeal and emetic toxins. Generally, isolates belonging to the B. cereus group with the same RAPD pattern were shown to have a similar profile of enterotoxigenicity.

An apparatus for generating atmospheric pressure plasma (APP) jet was used to investigate the inactivation of Listeria monocytogenes on the surface of agar plates and slices of cooked chicken breast and ham. He, N2 (both 7 L/min), and mixtures of each with O2 (0.07 L/min) were used to produce the plasma jets. After treatment for 2 min with APP jets of He, He þ O2 ,N 2 ,o r N 2 þ O2, the numbers of L. monocytogenes on agar plates were reduced by 0.87, 4.19, 4.26, and 7.59 log units, respectively. Similar treatments reduced the L. monocytogenes inoculated onto sliced chicken breast and ham by 1.37 to 4.73 and 1.94 to 6.52 log units, respectively, according to the input gas used with the N2 þ O2 mixture being the most effective. Most APP jets reduced the numbers of aerobic bacteria on the meat surfaces to