• Journal of Animal Science and Technology
• /
• v.52 no.2
• /
• pp.141-148
• /
• 2010

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.

• Journal of Soil and Groundwater Environment
• /
• v.18 no.1
• /
• pp.26-35
• /
• 2013

Outbreak of animal infectious diseases such as foot-and-mouth disease, avian influenza are becoming prevalent worldwide. For prevent the further infection, tremendous numbers of the infected or culled stocks are buried around farm. This burial method can generate a wide range of detrimental components such as leachate, nutrient, salt, and pathogenic bacteria, consequently. In this study, for the stabilization of livestock carcasses leachate, advanced oxidation processes utilizing the Fenton reaction was investigated in lab-scale experiments for the treatment for $COD_{Cr}$ of livestock carcass leachate. $COD_{Cr}$ reduction by the Fenton oxidation was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of pH ($x_1$), dosage of $FeCl_2{\cdot}4H_2O$ ($x_2$) and dosage of $H_2O_2$ ($x_3$) on the dependent variables $COD_{Cr}$ concentration ($y_1$). A 1 M NaOH and $H_2SO_4$ was using for pH control, $FeCl_2{\cdot}4H_2O$ was used as iron catalyst and NaOH was used for Fenton reaction. The optimal conditions for Fenton oxidation process were determined: pH, dosage of $FeCl_2{\cdot}4H_2O$ and dosage of $H_2O_2$ were 3, 0.6 g (0.0151 M) and 7 mL(0.259 M), respectively. Statistical results showed the order of significance of the independent variables to be pH > initial concentration of ferrous ion > initial concentration of hydrogen peroxide.

• Journal of Life Science
• /
• v.25 no.8
• /
• pp.910-916
• /
• 2015

Scientists have recently shown an interest in the characteristics of Bacillus mojavensis strains because of their increasing use in plants as a defense against diseases and mycotoxins. We have shown here that B. mojavensis KJS-3 possesses the typical characteristics of B. mojavensis strains including a strong resistance to high temperatures (≤50℃), tolerance to high salt concentrations (7% NaCl), ethanol tolerance (40% ethanol), and pH range for growth (pH 5-9). B. mojavensis KJS-3 has been used for the production of cyclic lipopeptides including important antifungal substances such as surfactin, iturin, and fengycin. Polymerase chain reaction analysis in this study showed that B. mojavensis KJS-3 can be used for the production of fengycin and the findings of LC-MS/MS analyses suggest that B. mojavensis KJS-3 can be used to produce iturin and surfactin. Antifungal activity analys is confirmed that B. mojavensis KJS-3 has antifungal effects on Botrytis cinerea, Rhizoctonia solani AG-4, Sclerotinia sclerotiorum, and Colletotricum goeosporioides. A microscopy assessment of the roots of wild ginseng plants planted together with B. mojavensis KJS-3 revealed that the roots contained B. mojavensis KJS-3, confirming the bacteria to be a plant growth promoting endophyte (PGPE) which acts against plant diseases and mycotoxins. Our findings lead us to conclude that B. mojavensis KJS-3 can be produced at an industrial level as a microbial pesticide or microbial fertilizer.

• Journal of dental hygiene science
• /
• v.13 no.2
• /
• pp.182-190
• /
• 2013

Composition of oral microbial flora is suggested to play a role in the maintenance of oral health. Among them, Streptococcus mutans plays an essential role in the formation of dental plaque and it is being noticed as incipient infective bacteria of dental caries. The purpose of this study was to prepare the basic data about distribution of Streptococcus mutans detected from saliva by measuring colony density. It is well known that smoking as well as drinking is a factor of dental caries, however there are few investigations about distribution of Streptococcus mutans either smoking or drinking. The materials of this study were collected from students of dentistry college with general characteristics obtained by self-administered questionnaires. Students were asked to gently chew the paraffin to get saliva for 1 minute. Bacitracin disc in the culture medium was activated for 15 minutes, and then sample was incubated in the activated medium at $37^{\circ}C$ incubator for 48 hours. Streptococcus mutans colonization per 1 ml saliva was measured by the number of criteria. The severe levels of dental caries activity were significantly increased in the case of smoking (from 5.6% to 10%) or drinking (form 0% to 7%), respectively. Also, dental caries activity increased according to smoking and drinking periods longer. However, using the SPSS analytical process (Mann-Whitney's U), no significant differences were observed between the smoking and the non-smoking or the drinking and non-drinking, respectively. These results obtained from dental caries activity of saliva suggest that distribution of Streptococcus mutans following smoking or drinking can be used as a significant information for oral health.

• Korean Journal of Veterinary Service
• /
• v.35 no.4
• /
• pp.313-319
• /
• 2012

Consumer's preference and microbial inspections on fresh raw beef were carried out to understand the actual market status in Gwanju, Korea. Over 15 questions on questionnaire by 1,111 randomly selected respondents between April and May in 2011, results showed 65.5% positive on eating fresh raw beef, 63.8% negative on good hygiene condition of fresh raw beef, and 72.5% positive on the secure of the hygiene-safety for priority program, respectively. For microbial inspections, a total of 302 samples were collected from fresh raw beef purchased from slaughterhouse (n=122), transport (n=69) and consumer (n=81) stage, from lettuce (n=30) at consumer stage. The aerobic plate count (APC), E. coli count and food borne bacteria such as Salmonella spp., Listeria monocytogenes, Staphylococcus(S.) aureus and E. coli O157:H7 were tested in the samples. As results, the level of count on APC of fresh raw beef ranged $6{\times}10^1{\sim}1.8{\times}10^5CFU/g$ from slaughterhouse, $2{\times}10^2{\sim}8.3{\times}10^5CFU/g$ from transport stage and $1{\times}10^2{\sim}4{\times}10^5CFU/g$ from consumer stage. The level of count on E. coli of fresh raw beef ranged $1{\sim}9{\times}10^1CFU/g$ from slaughterhouse, $1{\sim}7{\times}10CFU/g$ from transport stage and $1{\sim}5.5{\times}10CFU/g$ from consumer stage. In total, 26 S. aureus were isolated, 10 (14.5%) from fresh raw beef at transport stage, 12 (14.8%) from fresh raw beef and 4 (13.3%) from lettuce at consumer stage. Enterotoxin of S. aureus was not detected among 26 isolates. All S. aureus isolates were typed using a DiversiLab$^{TM}$ rep-PCR system for genetic similarity test, showing over 95% of genetic relationship amon isolates.

• Journal of Applied Biological Chemistry
• /
• v.55 no.3
• /
• pp.157-161
• /
• 2012

The aim of this research was to investigate the industrial application of Sedum sarmentosum. Antibacterial activities of the n-hexane, methylene chloride (MC), ethyl acetate, and n-butanol fractions of S. sarmentosum were tested against Escherichia coli, Staphylococcus aureus, and Helicobacter pylori. The MC fraction showed the strongest antibacterial activity against E. coli, with an inhibition zone greater than 13 mm in disc assays. At $100{\mu}g/mL$, all fractions scavenged more than 50% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals (${\cdot}OH$). In particular, the MC fraction showed the strongest scavenging activity against DPPH and ${\cdot}OH$. In addition, we found that treatment with the MC fraction inhibited the growth of H. pylori and gastric adenocarcinoma cells. The present results suggest that the MC fraction of S. sarmentosum would play the promising protective role against pathogenic bacteria and free radicals.

• Korean Journal of Agricultural Science
• /
• v.26 no.1
• /
• pp.50-57
• /
• 1999

The purpose of this study was to determine the thermal inactivation of L. monocytogenes KCTC3443 in liquid culture heated in the controlled microwave system and in the conventional heating method. Furthermore, we have carried out a comparative study on the thermal and nonthermal microwave effects on microorganisms, pasteurized using a controlled microwave energy specially designed apparatuses and a water bath. For the automatic temperature control during microwave heating, the real time data acquisition and computation system is designed with BASIC routine. The automatic temperature control system used in the experiments perform relatively stable control at the experiment temperature of 55, 65, $75^{\circ}C$ and $85^{\circ}C$ for 30 minutes. The effects of microwave heating on liquid cultures was compared with that of conventional heating. The results show that microwave radiation, while being slightly quicker than conventional heating, still reduces effectively the number of pathogenic bacteria during heating for a limit time in liquid cultures. While no particular differences between microwave heating and conventional heating was not observed in the thermal inactivation of L. monocytogenes at 55, 65, $75^{\circ}C$ and $85^{\circ}C$ for 30 min., respectively. Microwave heating is, therefore, substantially not effective in inactivating L. monocytogenes in liquid culture than conventional heating method.

• Journal of Life Science
• /
• v.28 no.3
• /
• pp.361-368
• /
• 2018

This study investigated the diversity of communities of intestinal microorganisms, separated from the intestinal organs of Red tilefish (Branchiostegus japonicas), collected on the Jeju Coast. First, in the isolation of 1.5% BHIA, MA, TSA and R2A Agar on the medium, there were most colonies in 1.5% BHIA. The results of aerobic culture and anaerobic culture were $1.7{\times}10^6CFU/g^{-1}$ and $1.1{\times}10^5cfu/g^{-1}$, respectively, on average, and 147 pure colonies were separated in total. In 16S rDNA sequencing, there were 58 genera and 74 species, showing 95-100% similarity with the basic strain. They were divided broadly into 5 phyla, and as the main phyletic group, Proteobacteria phylum comprised 50% with 9 families, 35 genera and 35 species of Moraxellaceae, Rhodobacteraceae, Shewanellae, Halomondaceae, Enterobacteriaceae, Vibrionaceae, Hahellaceae, Pseudomonadaceae, and Erythrobacteraceae, with the highest index of dominance. Actinobacteria phylum comprised 24% with 8 families, 11 genera and 17 species of Microbacteriaceae, Intrasporangiaceae, Dietziaceae, Dermabacteraceae, Dermacoccaceae, Nocardiodaceae, Brevibacteriaceae and Propionobacteriacea; Firmicutes phylum, 16% with 6 families, 8 genera and 17 species of Bacillaceae, Staphylcoccaceae, Planococcaceae, Streptococcaceae, Paenibacillaceae and Clostridiaceae; Bacteroidetes phylum, 6% with 2 families, 3 genera and 4 species of Cyclobacteriaceae and Flavobacteriaceae; and Deinococcus-Thermus phylum, 4% with 1 family, 1 genus and 1 species of Deinococcaceae.

• Korean Journal of Soil Science and Fertilizer
• /
• v.21 no.2
• /
• pp.141-148
• /
• 1988

Though the cultivation history of soybean in Korea is relatively long, taxonomical study on symbiont nodule bacteria, Rhizobium japonicum is not carried out yet systematically. This work was for the taxonomical study on Korean native R. japonicum by recognizing isolates seroimmunologically as well as for the elucidation of its affinity with host soybean variety. Twenty seven isolates from 13 soybean cultivars cultivated at Seoul National University's experiment field and 6 strains of R. japonicum preserved in our laboratory have been tested. Tube agglutination test, agglutinin adsorption test, and gel immune diffusion test were used. The results obtained are as follows: 1. Twenty five isolates and strains of R. japonicum among 33 were classified into 4 serogroups and identified as indivisual serotype. 2. Two isolates isolated from Hill and Milyang cultivars, 2 isolates from Bangsa and Jangbaek, and 4 isolates from Paldal, Sae-al, and Jangbaek were identified as the same serotype respectively. 3. Seroimmunological tests may be adapted for the elucidation of the affinities between the strains and soybean cultivars as well as strain recognition and systematic classification of Korean native R. japonicum.

• Microbiology and Biotechnology Letters
• /
• v.37 no.2
• /
• pp.125-132
• /
• 2009

In order to develop probiotics which may be a viable alternative of antibiotic use in pig industry, five bacterial strains (Lactobacillus sp. HN 52, 92, 98, 235 and AP 116) possessing antimicrobial properties were selected from 500 strains isolates of pig intestines. The bacteriocin produced by Lactobacillus sp. HN 235 displayed a relative broad spectrum of inhibitory activity against all Enterococcus strains, Pseudomonas aeruginosa, Listeria monocytogenes and Clostridium perfringens using the spot-on-lawn method. The production of antimicrobial substance started in the middle of the exponential growth phase, reached maximum levels (6,400 AU/mL) in the stationary phase, and then declined. Bacteriocin activity remained unchanged after 30 min of heat treatment at $95^{\circ}C$ and stable from pH 2.0 to 10 for 1 h, or exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. The molecular weight of the bacteriocin was about 5 kDa according to a tricine SDS-PAGE analysis.