• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.881-891
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• 2003

Paenibacillus polymyxa is a plant growth-promoting rhizobacterium (PGPR) which can be used for biological control of plant diseases. Several bacterial strains were isolated from rotten roots of Korean ginseng (Panax ginseng C. A. Meyer) that were in storage. These strains were identified as P. polymyxa, based on a RAPD analysis using a P. polymyxa-specific primer, cultural and physiological characteristics, an analysis utilizing the Biolog system, gas chromatography of fatty acid methyl esters (GC-FAME), and the 16S rDNA sequence analysis. These strains were found to cause the rot in stored ginseng roots. Twenty-six P. polymyxa strains, including twenty GBR strains, were phylogenetically classified into two groups according to the ERIC and BOX-PCR analyses and 16S rDNA sequencing, and the resulting groupings systematized to the degrees of virulence of each strain in causing root rot. In particular, highly virulent GBR strains clustered together, and this group may be considered as subspecies or biovar. The virulence of the strains seemed to be related to their starch hydrolysis enzyme activity, but not their cellulase or hemicellulase activity, since strains with reduced or no starch-hydrolytic activity showed little or no virulence. Artificial inoculation of the highly virulent strain GBR-1 onto the root surfaces of Korean ginseng resulted in small brown lesions which were sunken and confined to the outer portion of the root. Ginseng root discs inoculated in vitro or two-year-old roots grown in soil drenched with the inoculum developed significant rot only when the inoculum density was $10^{6}-10^{7}$ or more colony-forming units (CFU) per ml. These results suggest that P. polymyxa might induce ginseng root rot if their population levels are high. Based on these results, it is recommended that the concentration of P. polymyxa should be monitored, when it is used as a biocontrol agent of ginseng, especially in the treatment of stored roots.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.293-302
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• 2016

To determine the dominant bacterial species during the Saeu-jeotgal ripening process, the cultivable bacterial population was examined over a 135-day period using six different growth media. The greatest numbers of bacteria were identified when marine agar was used for culture, with maximum cell density identified at day 65 (2.51 × 10⁷ colony forming units/g). Over the course of 135 days, the bacterial diversity was analyzed eight times. A total of 467 isolates, comprising 87 species from 42 genera, as well as 16 isolates belonging to previously unknown species, were identified. The number of species detected decreased from 39 at day 1 to 13 at day 135. The order of dominance at the genus level was as follows: Staphylococcus, Salimicrobium, Kocuria, and Psychrobacter. Staphylococcus and Salimicrobium accounted for 2% of the diversity at day 1, and then increased to 39% and 36%, respectively, at day 135. The dominant species Staphylococcus equorum, Salimicrobium salexigens, and Kocuria palustris accounted for 23.6%, 16.1%, and 10.9% of all isolates, respectively. Importantly, both St. equorum and Sm. salexigens remained viable at a NaCl concentration of 21% (w/v), which indicates their strong involvement in the ripening of Saeu-jeotgal.

• Research in Plant Disease
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• v.20 no.3
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• pp.227-233
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• 2014

The mixture (MX) of acetic acid (AA) and lactic acid (LA) was examined for its effectiveness in the control of the pine wood nematode Bursaphelenchus xylophilus contaminated in cymbidium culture medium. Nematode mortality in vitro was nearly 100% in AA and MX at the concentrations of 5.0-1.0% (pH 2.6 - 4.2) and in LA only at 5.0% (pH 3.5), but lowered at concentrations of 0.5-0.1% (pH 5.1-6.9) more significantly in LA than AA and MX. MX of most concentrations caused higher nematode mortality than the average response to AA and LA. All treatments of MX (0.5% and 0.25%), fosthiazate (standard and double concentrations) and culture dilution of Paenibacillus polymyxa GBR-1 ($10^7$colony-forming units/ml) reduced significantly the nematode populations in the cymbidium culture medium, compared to non-treatment control, with no significant difference among the treatments. No phytotoxicity occurred in all treatments. pH of the medium with the time after treatment and growths of 2-year-old cymbidium were not significantly different among treatments. Considering the safety and price of the organic acids, use of MX in the processes for culturing cymbidium may be a practically reliable and eco-friendly way in the control of the quarantine nematode in cymbidium.

• Korean Journal of Poultry Science
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• v.42 no.4
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• pp.307-314
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• 2015

The study was carried out to investigate the effects of by-products of herbal medicines on performance, enteric microflora and blood biochemical profiles and immunological parameters in broiler chicks. A total of ninety-six, 3-d-old birds were assigned to a basal diet (CON) or a basal diet supplemented with 0.15 % (HM1), 0.3% (HM2) or 0.5% (HM3) by-products of herbal medicines. There was a significantly (p<0.05) improved feed conversion ratio (FCR) in birds fed diet supplemented with 0.15% by-products of herbal medicines (HM1) compared with the control birds during starter period (3~21 days). However, no difference in body weight, feed intake, total gain and FCR among treatment groups was observed during the entire feeding period (3~35 days). The colony forming units (CFU) of E. coli and Lactobacilli in the digesta of ileo-cecum was not also affected by dietary treatment. Serum AST (aspartate aminotransferase) and glucose decreased (p<0.05) in birds fed diets supplemented with herbal medicines compared with those fed the basal diet. In particular, the birds fed diets supplemented with herbal medicines showed a significant (p<0.05) increase in blood mean corpuscular volume (MCV) level compared with the control birds. However, the most of blood biochemical and hematological parameters and immunoglobulins (IgG and IgA) were not affected by the dietary treatment. In conclusion, the low level of dietary herbal medicines showed beneficial effects on FCR during starter period and liver functions, suggesting that by-products of herbal medicines may be applicable as functional feed additives in birds.

• Korean Journal of Microbiology
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• v.44 no.3
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• pp.203-211
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• 2008

Rapid detection-method for Shiga toxin type 1 that was produced from Shiga toxin-producing Escherichia coli (STEC) was developed by two-step ultra-rapid real-time (URRT) PCR. The specific primers were deduced from 80 bp stable region of stx type 1 (stxl) gene among various informations of STEC strains. URRT PCR is a microchip-based real-time PCR using 6 ${\mu}l$ of reaction volume with extremely short denaturation step and annealing/extension step (1 sec, 3 sec, respectively) in each cycle of PCR. Using the stx1-specific URRT PCR, 35 cycled PCR were finished in time of 6 min and 38 see, also measured 7 min and 28 see including melting temperature (Tm) analysis. The detection-limit of stxl-specific URRT-PCR was estimated until 3 colony forming units / PCR with products with stable Tm at $81.42{\pm}0.34^{\circ}C$. In the applications to various STEC strains and contaminated genomic DNAs, stx1-specific URRT-PCR were tested and shown that it would be expected an useful method for the rapid detection of stx1-coded STEC strains.

• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.527-533
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• 2021

Objectives: Electrolyzed water has been proven to have antibacterial effects against various microorganisms. However, there are only a few studies about effects of electrolyzed water on oral bacteria. The purpose of this study was to examine the antibacterial effect of electrolyzed water on Streptococcus mutans in vitro. Methods: S. mutans KCOM 1054 was treated with electrolyzed water for 1 or 3 minutes and plated on Mitis Salivarius agar with 15% sucrose and bacitracin. After incubation for 48 hours, colony forming units (CFU) were counted, and dental plaque was quantified by crystal violet staining. Results: The growth of S. mutans was significantly inhibited by electrolyzed water (p<0.001). In addition, the dental plaque formation by S. mutans was decreased in a time-dependent manner by exposure to electrolyzed water (p<0.001). Conclusions: Our results suggest that electrolyzed water can effectively prevent dental caries by inhibiting growth of (and the formation of dental plaque by) S. mutans.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.12
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• pp.1897-1902
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• 2018

Objective: This study was conducted to evaluate the effect of homo or hetero fermentative inoculants on fermentation quality and aerobic stability of sweet potato vine (SPV) silage containing Italian ryegrass hay as moisture absorbent. Methods: The SPV was harvested at 15% dry matter, mixed with Italian ryegrass hay at 1:1 ratio on a fresh weight basis, and chopped to 3 to 5 cm length. After then, the chopped forage mixture was ensiled into 20-L mini silos in quadruplicate for 7, 48, and 100 days after application of microbial inoculants at $1.2{\times}10^5$ colony forming units (cfu)/g of forage following: no inoculant (CON), Lactobacillus plantarum as a homo fermentative (LP), Lactobacillus buchneri as a hetero fermentative (LB), and mixture of LP and LB at 1:1 ratio as a combo fermentative (MIX). Results: The LP and MIX silages had lowest pH (p<0.001) on 7 and 48 days, while MIX and CON silages had greatest lactate concentrations (p<0.05) on 7 and 48 days, respectively. Acetate concentrations were highest (p<0.01) in LB and MIX silages on 7 days, and in LB silage on 48 days, while lactate to acetate ratios were lowest (p<0.001) in LB silages. The chemical compositions and nutrient digestibility of silage ensiled for 100 days was not affected by inoculants. On 100 days of ensiling, LB silage had lowest (p<0.01) lactate concentration and lactate to acetate ratio, but highest acetate concentration. Aerobic stability was highest (p<0.001) in LB silage followed in MIX silage. On contrast, LB silage had lowest (p<0.05) lactic acid bacteria and mold. Conclusion: The results indicated that application of LB solely had a better effect on aerobic stability than not only LP, but also MIX. However, LP application did not show beneficial effects from the viewpoints of fermentation quality and aerobic stability compared to CON.

• Clinical and Experimental Pediatrics
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• v.48 no.9
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• pp.986-990
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• 2005

Purpose : Certain strains of lactobacilli are known to accelerate recovery from acute diarrhea. Lactobacillus reuteri is isolated from human breast milk and a commonly occurring Lactobacillus species with therapeutic potential in acute diarrhea. The purpose of the present study was to investigate the therapeutic effect of L. reuteri in acute diarrhea in young children. Methods : Fifty patients between 6 and 36 months of age hospitalized with acute diarrhea (rotavirus in 40 percent) were randomized into two groups to receive either $10^8$ colony-forming units of L. reuteri or a matching placebo, twice a day for their length of hospitalization, or for up to 5 days. Antidiarrheal drugs were not prescribed to either group. The clinical outcome of diarrhea was evaluated. Results : The mean duration of watery diarrhea after initiation of treatment was 2.3 days for the L. leuteri group(n=25) vs. 2.9 days for the placebo group(n=25)(P=0.072). By the second day of treatment, watery diarrhea persisted in 64 percent of patients receiving L. reuteri, compared to 84 percent of those receiving placebo(P=0.006). On the second day, the mean frequency of watery diarrhea was 1.9 in the L. leuteri group and 3.4 in the placebo(P=0.046). Also, vomiting continued to the second day in 16 percent of patients receiving L. reuteri and 40 percent of those recieving placebo(P=0.031). Conclusion : L. reuteri is effective as a therapeutic agent in acute diarrhea in children.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.321-330
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• 1999

Background : Early diagnosis and proper antibiotic treatment are very important in the management of ventilator-associated pneumonia (VAP) because of its high mortality. Bronchoscopy with a protected specimen brush (PSB) has been considered the standard method to isolate the causative organisms of VAP. However, this method burdens consumer economically to purchase a PSB. Another useful method for the diagnosis of VAP is quantitative cultures of aspirated specimens through bronchoscopic bronchoalveolar lavage (BAL), for which the infusion of more than 120 m1 of saline has been recommended for adequate sampling of a pulmonary segment. However, occasionally it leads to deterioration of the patient's condition. We studied the diagnostic efficacy of minibronchoalveolar lavage (miniBAL), which retrieves only 25 ml of BAL fluid, in the isolation of causative organisms of VAP. Methods: We included 38 consecutive patients (41 cases) suspected of having VAP on the basis of clinical evidence, who had received antibiotics before the bronchoscopy. The two diagnostic techniques of PSB and miniBAL, which were performed one after another at the same pulmonary segment, 'were compared prospectively. The cut-off values for quantitative cultures to define causative bacteria of VAP were more than $10^3$ colony-forming units (cfu)/ml for PSB and more than $10^4$ cfu/ml for BAL. Results: The amount of instilled normal saline required to retrieve 25 ml of BAL fluid was $93{\pm}32 ml$ (mean${\pm}$SD). The detection rate of causative agents was 46.3% (19/41) with PSB and 43.9% (18/41) with miniBAL. The concordance rate of PSB and miniBAL in the bacterial culture was 85.4% (35/41). Although arterial blood oxygen saturation dropped significantly (p<0.05) during ($92{\pm}10%$) and 10 min after ($95{\pm}3%$) miniBAL compared with the baseline ($97{\pm}3%$), all except 3 cases were within normal ranges. The significantly elevated heart rate during ($l25{\pm}24$/min, p<0.05) miniBAL compared with the baseline ($1l1{\pm}22$/min) recovered again in 10 min after ($111{\pm}26$/min) miniBAL. Transient hypotension was developed during the procedure in two cases. The procedure was stopped in one case due to atrial flutter. Conclusion: MiniBAL is a safe and effective technique to detect the causative organisms of VAP.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.611-620
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• 2007

The current study was designed to define whether a blend of prunus mume extract(25%) containing lactic acid(75%) and grape seed extract(10ppm) could affect in vitro antimicrobial activity and growth performance, intestinal microflora, plasma biochemical profiles and digestive enzymes activities in broiler chickens. In paper disc agar diffusion test, we clearly observed antimicrobial activity against E. coli in response to prunus mume extract or a blend of prunus mume extract. For in vivo test, a total of ninety six 3-d-old male broiler chicks were assigned to basal diet(CON), basal diet supplemented with antibiotics (ANTI) and 0.5% a blend of prunus mume extract(PRNUS) until 35 days of age. Throughout the entire experimental period(3-35 days), there were no differences in BW and FCR between the birds fed the basal diet with antibiotics and the diet supplemented with a blend of prunus mume. However, ANTI group showed a significant increase in BW and total gain compared to CON group. The weights of digestive organs such as the pancreas and mucosal tissues were not affected by dietary treatments. There was no difference in plasma levels of glucose, cholesterol, AST and ALT activity. However, triglyceride in plasma increased(P<0.05) in the birds fed the diet supplemented with 0.5% a blend of prunus mume extract compared to those fed antibiotics supplemented diet. The activities of pancreatic trypsin and amylase, and intestinal hydrolase including disaccharidase were not affected by dietary treatment. The colony forming units(CFU) of lactobacillus in the lower ileal-cecum of the birds fed the diet supplemented with a blend of prunus mume extract was significantly(P<0.05) higher than that of birds fed antibiotic supplemented diet without affecting the CFU of E. coli. In conclusion, the birds fed the diet supplemented a blend of prunus mume as an alternative to antibiotics showed a similar growth performance and an significant increase in lactobacillus population compared with the birds fed basal and antibiotics supplemented diets.