• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.378-384
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• 2007

Three microorganisms and one chemical preservative were tested for their effects on the fermentation and aerobic stability of whole-crop wheat, sorghum and maize silages. Wheat at the early dough stage, sorghum at the late milk stage and maize at the one-third milk line stage were harvested and ensiled in 1.5-l anaerobic jars untreated or after the following treatments: control (no additives); Lactobacillus plantarum (LP) at $1.0{\times}10^6$ colony-forming units (CFU)/g of fresh forage; L. buchneri (LB) at $1.0{\times}10^6$ CFU/g; Propionibacterium acidipropionici (PA) at $1.0{\times}10^6$ CFU/g; and a formic acid-based preservative (FAP) at 3 ml/kg of fresh forage weight. Three jars per treatment were sampled on d 90 after ensiling, for chemical and microbiological analysis. At the end of the ensiling period, 90 d, the silages were subjected to an aerobic stability test lasting 5 d. In this test, $CO_2$ produced during aerobic exposure was measured along with chemical and microbiological parameters which serve as spoilage indicators. The silages inoculated with LP had higher concentration of lactic acid compared with the controls and the other treated silages (p<0.05). The controls and LP-inoculated silages spoiled upon aerobic exposure faster than LB, PA and FAP-treated silages. The controls and LP-inoculated silages spoiled upon aerobic exposure faster than LB, PA and FAP-treated silages due to more $CO_2$ production (p<0.05) in these two groups and development of yeasts unlike the other groups. In the experiment, the silages treated with LB, PA and FAP were stable under aerobic conditions. However, the numbers of yeasts was higher in the LP-inoculated wheat, sorghum and maize silages compared with the LB, PA and FAP-treated silages. The LB, PA and FAP improved the aerobic stability of the silages by causing more extensive heterolactic fermentation that resulted in the silages with high levels of acetic and propionic acid. The use of LB, PA and FAP as silage additives can improve the aerobic stability of whole-crop wheat, sorghum and maize silages by inhibition of yeast activity.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.401-409
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• 2004

Two experiments were conducted to evaluate the effects of a complex Lactobacilli preparation on performance, resistance to E. coli infection and gut microbial flora of weaning pigs. In exp. 1, twelve pigs (7.65$\pm$1.10 kg BW), weaned at 28 d, were randomly allotted into 2 groups and placed in individual metabolic cages. During the first 7 d, one group of pigs was provided ad libitum access to water containing $10^5$ colony forming units (CFU) Lactobacilli per ml and the control group was provided tap water. The Lactobacilli preparation included Lactobacillus gasseri, L. reuteri, L. acidophilus and L. fermentum, which were isolated from the gastrointestinal (GI) tract mucosa of weaning pigs. On d 8, 20 ml of $10^8$ CFU/ml E. coli solution (serovars K99, K88 and 987P at the ratio of 1:1:1) was orally administered to each pig. Diarrhea scores and diarrhea incidence were recorded from d 7 to 14. On d 14, pigs were euthanized and digesta and mucosa from the stomach, duodenum, jejunum, ileum, cecum and colon were sampled using aseptic technique to determine microflora by culturing bacteria in selective medium. The results showed that Lactobacilli treatment significantly decreased E. coli and aerobe counts (p<0.01) but increased Lactobacilli and anaerobe counts (p<0.01) in digesta and mucosa of most sections of the GI tract. A 66 and 69.1% decrease in diarrhea index and diarrhea incidence, respectively, was observed in the Lactobacilli treated group. In exp. 2, Thirty-six crossbred Duroc$\times$Landrace$\times$Yorkshire piglets, weaned at 28$\pm$2 days, were selected and randomly allocated into 2 groups. There were 18 piglets in each group, 3 piglets in one pen and 6 replicates in each treatment with 3 pens of barrow and 3 pens of female piglet in each treatment. Piglets had ad libitum access to feed and water. The initial body weight of piglet was 7.65$\pm$1.09 kg. Dietary treatments included a non-medicated basal diet with Lactobacilli ($10^5$ CFU/g diet) or carbadox (60 mg/kg) as control. On d 21, six pigs per group (one pig per pen) were euthanized. Ileal digesta was collected to determine apparent amino acid digestibility. Microflora content was determined similarly to exp.1. The results showed that Lactobacilli treatment significantly improved average daily feed intake (ADFI) of pigs compared to carbadox (p<0.05) during the first 2 wks after weaning and average daily gain (ADG) and ADFI increased significantly (p<0.05) from d 8 to 14. Nitrogen and total phosphorus digestibility also increased (p<0.05). Bacterial counts were similar to exp. 1. The results indicate that the complex Lactobacilli preparation improved performance for 2 wks after weaning, enhanced resistance to E. coli infection, and improved microbial balance in the GI tract.

• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.11-11
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• 2015

A total of sixty-six samples of Nuruk, a fermention starter used to make the Korean traditional rice wine, Makgeolli, were collected from central and southern regions of Korea in 2013 and 2014. We classified two groups of the Nuruk samples, "commercial" and "home-made", according to the manufacturing procedure and purpose of use. Commercial Nuruks were made in a controlled environment where the temperature and humidity are fixed and the final product is supplied to Makgeolli manufacturers. Home-made Nuruks were made under uncontrolled conditions in the naturally opened environment and were intended for use in the production of small amounts of home-brewed Makgeolli. We obtained more than five hundred isolates including filamentous fungi and yeasts from the Nuruk samples followed by identification of fungal species. Also we stored glycerol stocks of each single isolate at $-70^{\circ}C$. We identified the species of each isolate based on the sequences of ITS regions amplified with two different universal primer pairs. We also performed morphological characterization of the filamentous fungi and yeast species through observations under the microscope. We investigated the major fungal species of commercial and home-made Nuruks by counting the colony forming units (CFU) and analyzing the occurrence tendency of fungal species. While commercial Nuruks contained mostly high CFU of yeasts, home-made Nuruks showed relatively high occurrence of filamentous fungi. One of the representative Nuruk manufacturers used both domestic wheat bran and imported ones, mainly from US, as raw material. Depending on the source of ingredient, the fungal diversity was somewhat different. Another commercial Nuruk sample was collected twice, once in 2013 and again in 2014, and showed different diversity of fungal species in each year. Nuruks obtained from the southern regions of Korea and Jeju island showed high frequency of yeast such as Saccharomycopsis fibuligera and Pichia species as well as unique filamentous fungus, Monascus species. S. fibuligera was easily found in many Nuruk samples with high CFU. The major filamentous fungi were Aspergillus, Lichtheimia, Mucor and Penicillium species. In order to further our understanding of the isolates and their potential industrial applications, we assayed three enzymes, alpha amylase, glucoamylase and acid protease from 140 isolates out of about five hundred isolates and selected about 10 excellent strains with high enzyme activities. With these fungal isolates, we will perform omics analyses including genomics, transcriptomics, metabolic pathway analyses, and metabolomics followed by whole genome sequencing of unique isolates associated with the basic research of Nuruk and that also has applications in the Makgeolli making process.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.202-205
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• 2010

Introduction: The aim of the present study was to investigate the effect of mechanical irrigation in combination with mouthwash of antimicrobial agents on salivary bacterial counts. Materials and Methods: This study was performed with a randomized study employing a panel of 40 healthy volunteers (20 males and 20 females) between the age of 26 and 32 years. Volunteers were randomly put in one of four treatment groups. In the first group, 0.2 mL of non-stimulatory saliva was collected from every subjective person. Then, saliva was collected after rinsing with chlorhexidine (CHX) for 1 minute. In the second group, non-stimulatory saliva was collected, and then saliva was collected after rinsing with CHX and irrigation with saline. In the third and fourth groups, the same procedures as the first and second groups were performed with povidone iodine (PVI) instead of CHX. All of these samples were cultured for 48 hours aerobically. The reduction rates of colony-forming units (CFU) were calculated for each group. The reduction rate between each group was tested statistically using student t-test. Results: Using CHX in combination with saline irrigation showed a significant decrease of the salivary bacterial CFU when compared with only using CHX.(P<0.01) And using PVI with saline irrigation showed a little decrease of the CFU when compared with only using PVI, but there was no statistical significance.(P>0.01) Conclusion: It was concluded that the CHX or PVI used with saline irrigation made the salivary bacterial counts reduced more than when CHX or PVI was used alone as an oral antiseptic agent.

• Journal of Food Hygiene and Safety
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• v.39 no.4
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• pp.335-342
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• 2024

This study aimed to examine the delivery conditions and microbial contamination of fresh-cut and ready-to-eat foods purchased from online markets between February and November 2023. Upon arrival, the average surface temperature of the products was 11.3℃. In the fresh-cut foods, the average number of total aerobic bacteria and coliforms was 4.5 log colony-forming units (CFU)/g and 1.2 log CFU/g, respectively, whereas in the ready-to-eat foods, these values were 10.6 log CFU/g and 1.2 log CFU/g, respectively. Pathogens, such as Staphylococcus aureus, Salmonella spp., Clostridium perfringens, Listeria monocytogenes, and pathogenic Escherichia coli were absent from all samples. Bacillus cereus was found in 2.7% of the fresh-cut foods and 0.9% of the ready-to-eat foods, with contamination levels averaging 0.05 log CFU/g and 0.01 log CFU/g, respectively. In the four samples in which B. cereus was detected, genetic testing of the six toxin genes produced by B. cereus revealed the presence of at least one enterotoxin gene, excluding the emetic toxin. L. monocytogenes was absent from ready-to-eat foods but was detected in 0.9% of fresh-cut foods. Analysis of the isolated L. monocytogenes confirmed the presence of six pathogenicity-related genes, including iap, indicating the potential risk of foodborne diseases.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.738-744
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• 2015

Tuberculosis is one of the most threatening infectious diseases to public health all over the world, for which Mycobacterium tuberculosis (MTB) is the etiological agent of pathogenesis. Ursolic acid (UA) has immunomodulatory function and exhibits antimycobacterial activity. However, the intracellular killing effect of UA has yet to be elucidated. The aim of this study was to evaluate the intracellular killing effect of UA during mycobacterial infection. The intracellular killing activity of UA was evaluated in the macrophage cell line THP-1 by the MGIT 960 system as well as by CFU count. The production of reactive oxygen species (ROS) and the level of nitric oxide (NO) were measured using DCF-DA and Griess reagent, respectively. Phagocytosis was observed by a fluorescence-based staining method, and the colony forming units were enumerated on 7H11 agar medium following infection. In addition, MRP8 mRNA expression was measured by qRT-PCR. UA significantly decreased the number of intracellular Mycobacterium through generation of ROS and NO. In addition, it profoundly activated the phagocytosis process of THP-1 cells during MTB-infection. Furthermore, our data demonstrated that UA activated the phagocytosis process in human monocyte cells through MRP8 induction. These data suggest that UA firmly contributes to the intracellular killing effect of macrophages during mycobacterial infection.

• Journal of the Korean Society of Tobacco Science
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• v.30 no.1
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• pp.1-7
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• 2008

Bacterial wilt caused by Ralstonia solanacearum has become a severe problem on tobacco in Korea. No effective single control measure is available at present time. One of the most potential way for controlling the bacterial wilt on tobacco is growing tobacco cultivars resistant to the bacterial wilt. In this study, optimal conditions for screening tobacco cultivars resistant to the bacterial wilt were examined to provide reproducible and efficient methods in growth chamber testing and field experiments for evaluating plant disease resistance. For this, already-known inoculation methods, inoculum densities, and incubation temperature, and plant growth stages at the time of inoculation were compared using tobacco cultivars resistant (Nicotiana tabacum cv, NC95), moderately resistant (N. tabacum cv. SPG70), and susceptible (N. tabacum BY4) to the bacterial disease. It was determined that root-dipping of tobacco seedlings at six true leaf stage into the bacterial suspension with inoculum level of $10^8$ colony-forming units (CFU)/ml for 20 min before transplanting was simple and most efficient in testing for resistance to the bacterial wilt of tobacco caused by R. solanacearum, for which disease incidences and severities were examined at 2 weeks of plant growth after inoculation at $20{\sim}25^{\circ}C$ in a growth chamber. These experimental conditions could discriminate one tobacco cultivar from the others by disease severity better than any other experimental conditions. In field testing, the optimum time for examining the disease occurrence was late June through early July. These results can be applied to establishing a technical manual for the screening of resistant tobacco cultivars against the bacterial wilt caused by R. solanacearum.

• Journal of Periodontal and Implant Science
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• v.45 no.2
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• pp.38-45
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• 2015

Purpose: The purpose of this study was to evaluate the effect of photodynamic therapy (PDT) using erythrosine and a green light emitting diode (LED) light source on biofilms of Aggregatibacter actinomycetemcomitans attached to resorbable blasted media (RBM) and sandblasted, large-grit, acid-etched (SLA) titanium surfaces in vitro. Methods: RBM and SLA disks were subdivided into four groups, including one control group and three test groups (referred to as E0, E30, E60), in order to evaluate the effect of PDT on each surface. The E0 group was put into $500{\mu}L$ of $20{\mu}M$ erythrosine for 60 seconds without irradiation, the E30 group was put into erythrosine for 60 seconds and was then irradiated with a LED for 30 seconds, and the E60 group was put into erythrosine for 60 seconds and then irradiated with a LED for 60 seconds. After PDT, sonication was performed in order to detach the bacteria, the plates were incubated under anaerobic conditions on brucella blood agar plates for 72 hours at $37^{\circ}C$, and the number of colony-forming units (CFUs) was determined. Results: Significant differences were found between the control group and the E30 and E60 groups (P<0.05). A significantly lower quantity of CFU/mL was found in the E30 and E60 groups on both titanium disk surfaces. In confocal scanning laser microscopy images, increased bacterial death was observed when disks were irradiated for a longer period of time. Conclusions: These findings suggest that PDT using erythrosine and a green LED is effective in reducing the viability of A. actinomycetemcomitans attached to surface-modified titanium in vitro.

• The Korean Journal of Food And Nutrition
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• v.22 no.4
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• pp.492-496
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• 2009

The composition of the bacterial populations in Gorosoe(Acer mono Max.) sap was characterized during storage with different heat treatments($63^{\circ}C$ for 30 min and $73^{\circ}C$ for 15 sec). The saps were aseptically collected at 0, 15 and 30 days of storage and analyzed by dilution plating and 16S rDNA PCR-DGGE analysis. There were significant differences in the total number of colony forming units(CFUs) of bacteria between heated and nonheated saps. Bacteria of nonheated sap were present at a level of $3.4{\times}10^7CFU/m{\ell}^{-1}$, whereas living bacteria were not detected in the heated sap. According to the 16S rDNA sequence and DGGE analysis, Pseudomonas sp. was the most abundant bacterial strain in the samlpes, and the bacterial community structures become more simplified with time and were composed of the Chryseobacterium sp. with time. These results allowed us to characterize the dominant bacteria involved in Gorosoe sap and to better understand their dynamics throughout storage.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.1
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• pp.6-10
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• 2015

Photodynamic therapy (PDT) apply photosensitizers and light. The purpose of this study was to evaluate the in vitro efficacy of PDT using blue LED (light emitting diode) with photofrin and radachlorin for Propionibacterium acnes. The colony forming units method was used to assess the antibacterial activity. Suspension (1 mL) containing P. acnes at $1{\times}10^5CFU/mL$ were prepared and then 2 fold serial diluted to $12.5{\mu}g/mL$ from $50{\mu}g/mL$ concentration of photofrin and radachlorin. After 60 minutes incubation, light was irradiated for 10 to 30 minutes using the following light source of wavelength 460 nm, each energy density 36, 72 and $108J/cm^2$. Bacterial growth was evaluated after 72 hours incubation in a Phenylethanol Blood Agar (PEBA) culture. In addition, flow cytometric analysis were performed to measure the live cell after PDT. Also transmission electron microscopy (TEM) was employed to evaluate the effect of pathogens by PDT. The PDT Group was perfectly killed to all kind of photosensitizers dose of $12.5{\mu}g/mL$ with irradiation of 10 minutes. Also other Groups were killed to all kind of photosensitizers dose of $6.25{\mu}g/mL$ with irradiation time of 20 and 30 minutes. The flow cytometry showed a lower number of viable bacteria in the PDT group compared to the control group. The images of the TEM results were showed in cytoplasmic membrane damage and partially deformed to cell morphologies. These results suggest that radachlorin and photofrin combine blue LED PDT can be effectively treated when was proved treatment for acnes therapy.