• Applied Biological Chemistry
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• v.40 no.6
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• pp.561-566
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• 1997

Screening, Identification and some cultural characteristics of ALA$({\delta}-aminolevulinic\;acid)$-producing photosynthetic bacteria were carried out for the optimal production of ALA, one of the bioherbicides. Among photosynthetic bacteria isolated from soil, marsh, pond, etc., KK-10 was the best producer of ALA and identified to be Rhodobacter capsulatus belonging to a typical group of nonsulfur purple bacteria. By addition of 15 mM LA (levulinic acid), an inhibitor of ALA dehydrase in cyclic tetrapyrrole biosynthesis, into culture broth at middle log phase of cell growths, ALA production was considerably increased to about 20-fold (28 mg/l). The combined supplementation of glycine and succinate, each with a concentration of 30 mM also enhanced production of ALA and activity of ALA synthase to about 50-fold (73 mg/l) and 2-fold, respectively. The isolated strain was able to produce upto 80 mg/l under the cultural condition optimized by addition 15 mM LA into the synthetic medium at four different points starting middle log phase.

• Korean Journal of Microbiology
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• v.36 no.3
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• pp.209-215
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• 2000

The purpose of U7is work was to iilvestigate the degradation of s-h~azine hel-hicidcs, ahilzine and simazine by TNT-degrader under several relevaut physicochemical environ~nental parameters. TNT-degrader showed effective degradability of atrazine and snnazine as well. Both atrazme (GO 1i1~11) and simazine ( 4 5 rng//) were completely degraded within 30 hrs and 4 days of incubation, respectively. As d ~ e concentrations of atrazine and sunazine increased in the media, the degradation ofthose compounds were delayed. Additional caubans were essential to degrade atrazine and simazule, and no degradation was achieved in the absence of additional carbons. The effect of supplemented nitrogens on the degradation of atrazine and sunazine was evalualed. Addition of a suppleinented nitrogen in he growth medium containing ah-azine or siinazine showed partial degr-adation olihose herbicides duriug the incubation period. However, complete degradation of atrazine and simazu~e was examined ul the absence or any supplemented nitrogens. Addltion of yeast extract in this study was inhibilory to atrazine aud siinazine degradations, respectively. TNT-degrader was a small Gram-negative cocco-bacillus. Physiological analysis using BIOLOG sysleln revealed that this strain was Ste~~ol~~opl~orno~~ns rrialtophilia.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.330-337
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• 1997

The sensitivity of various pathogenic bacteria (Aeromonas hydrophila, Estherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus 196E, Salmonella typhimurium and Vibrio parahaemolyticus) to the spices, allspice, clove, oregano, and thyme, was tested. Tryptic soy broth (TSB) containing 0∼2% (w/v) of spices was inoculated with 10sup 5/∼10$\^$6/ cells/$m\ell$ of each bacterium and incubated at 35$^{\circ}C$ for 24 hr. The growth of pathogenic bacteria was inhibited with increasing concentrations of spices in the culture broth. At 2％ spice concentration, Gram positive bacteria were more sensitive than Gram negative bacteria with the exception of V. parahaemolyticus. Clove had the highest antibacterial activity, followed by allspice and oregano. At the concentration of 0.3%, clove inhibited the growth of all strains tested. Kanagawa-positive strain of V. parahaemolyticus displayed the highest sensitivity to clove and allspice. Thyme was the least effective for growth inhibition, while 1％ clove killed all pathogens tested.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.18-23
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• 2005

The purpose of this work was to investigate the physiological characteristics of Lactobacillus sp. JK-8 isolated from a shrimp aquaculture pond. The strain JK-8 was grown on MRS media, and morphological and physiological characteristics of the strain were examined. The bacterium was identified as a strain of the genus Lactobacillus on the basis of BIOLOG test. Strain JK-8 produced both lactic acid and acetic acid, which were responsible for the pH decrease during growth. Concentrations of lactic acid and acetic acid increased to 192.8 mM and 43.6 mM, respectively, and the initial pH 7.0 of the cultures decreased to 3.8 at the end of incubaction. The bacteriocidal effect against eight target bacteria was examined with 5-fold concentrated culture supernatants. All bacteria tested in this work were completely killed within 3 hrs after treatment with the culture supernatant. The bacteriocidal effects were clearly observed, only when the pH of the culture supernatants were not adjusted. HPLC was used to reslove lactic acid and acetic acid in the culture solution, and GC-MS was used to verify the metabolites.

• Pediatric Infection and Vaccine
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• v.28 no.2
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• pp.118-123
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• 2021

Culture tests are very important in choosing the appropriate antibiotics for bacterial infections. In some cases, bacteria that could not be identified in standard culture bottles could be detected using blood culture bottles. A previously healthy 13-year-old boy visited our emergency room. He experienced pain, redness, and hardness of periumbilical skin and a fever for five days. There was no history of abdominal surgery and penetrating trauma. Computed tomography showed abscess with cellulitis at the periumbilical soft tissue with no congenital anomaly. Ultrasonography-guided aspiration was performed, and about 8.5 mL of the purulent abscess was aspirated. The abscess was cultured using blood culture bottle. The pus grew Actinomyces radingae and Clostridium ramosum. When performing the pus culture, using blood culture bottles can be more effective and rapid than the standard culture method for the detection of bacterial pathogens.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.3
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• pp.232-239
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• 2009

This research investigated the characteristics of antibiotic resistance of bacteria in microbial communities from municipal wastewater treatment plants (MWTPs), and monitored seasonal changes of antibiotic resistant bacteria (ARB) from MWTPs and Han river. When antibiotics were amended to either R2A agar (R2A) for general heterotrophs or MacConeky sorbitol agar (MSA) for coliform bacteria, all the MWTP samples exhibited multiple antibiotic resistance on the antibiotic-amended solid media. The antibiotic resistance appearing frequencies of ampicillin and sulfathiazole, respectively, were higher than reported data for other countries. The antibiotic resistance appearances differed depending upon the concentrations of primary substrate and nutrients and the types of cultivation media. The following 16S rRNA gene phylogenetic analysis showed that the identified multiple-antibiotic resistant microbes on R2A plates were more likely to be known human-pathogenic bacteria than the background heterotrophic bacteria were, suggesting a high risk of antibiotic resistance appearance to public health. In addition, according to our investigation of seasonal changes of ARB from urban MWTP and river samples, the frequency of ARB appearances was shown to correlate positively with temperature. This indicates a possibility that global warming result in increase in microbial risk to public health.

• Journal of Oral Medicine and Pain
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• v.34 no.1
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• pp.39-48
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• 2009

Recently there is much interest in the antibacterial activity of nano-sized silver particle (nanosilver) since silver is known to be safe and effective as disinfectant for a long time. Oral malodor is considered to originate in the oral cavity primarily as a result of production of malodorous compounds by oral bacteria. Major compounds responsible for oral malodor are volatile sulfur compounds, which is thought to be generated by the G(-) anaerobic bacteria found normally in the oral cavity, especially on the dorsum of the tongue. The purposes of this study were to investigate the effect of nanosilver on growth of oral malodor generating microorganisms, including Fusobacterium nucleatum, Prevotella melaninogenica, Klebsiella pneumonia, and to determine the optimal culture condition of them. The results were as follows: 1. The optimal culture condition for P. melaninogenica was vacuum culture using desiccator after evacuation of air by vacuum pump in chopped beef meat media. 2. The growth of K. pneumonia was temporarily inhibited by nanosilver (5 ppm and 10 ppm). 3. The morphological alteration and cell damage caused by nanosilver were observed in K. pneumonia.

• Journal of dental hygiene science
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• v.17 no.4
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• pp.283-289
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• 2017

The water discharged from dental unit waterlines (DUWLs) is heavily contaminated with bacteria. The development of efficient disinfectants is required to maintain good quality DUWL water. The purpose of this study was to establish a DUWL biofilm model using well-plates to confirm the effectiveness of disinfectants in the laboratory. Bacteria were obtained from the water discharged from DUWLs and incubated in R2A liquid medium for 10 days. The bacterial solution cultured for 10 days was made into stock and these stocks were incubated in R2A broth and batch mode for 5 days. Batch-cultured bacterial culture solution and polyurethane tubing sections were incubated in 12-well plates for 4 days. Biofilm accumulation was confirmed through plating on R2A solid medium. In addition, the thickness of the biofilm and the shape and distribution of the constituent bacteria were confirmed using confocal laser microscopy and scanning electron microscopy. The average accumulation of the cultured biofilm over 4 days amounted to $1.15{\times}10^7CFU/cm^2$. The biofilm was widely distributed on the inner surface of the polyurethane tubing and consisted of cocci, short-length rods and medium-length rods. The biofilm thickness ranged from $2{\mu}m$ to $7{\mu}m$. The DUWL biofilm model produced in this study can be used to develop disinfectants and study DUWL biofilm-forming bacteria.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.167-172
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• 1977

Colony morphology, growth responses on some simple carbon sources and taxonomic position were established for three stock cultures of National Collection of Industrial Bacteria, Scotland. It was confirmed that NCIB 8077 belonged to the Cellulomonas species and that NCIB 8633 and NCIB 8634 belonged to the Pseudomonas species. Taxonomy of other cellulolytic bacteria published on various journals was also discussed.

• Pediatric Infection and Vaccine
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• v.16 no.2
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• pp.131-141
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• 2009

Purpose : In February 2007, an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections occurred in two newborns in the neonatal unit of Sahmyook Seoul Hospital. We performed this study to investigate the characteristics of MRSA nasal carriage among neonatal unit staffs and the effective infection control measures. Methods : Nasal swab specimens were obtained from the neonatal unit staff for the presence of MRSA. MRSA-colonized staffs were offered decolonization therapy with oral trimethoprim-sulfamethoxazole or 2% mupirocin ointment. Every 2-4months after decolonizaton, repeat nasal swab specimens were obtained. Also, samples from the neonatal unit environment and room air were collected. Results : Successful decolonization was achieved in 92% of the cases in 2 weeks after decolonization therapy, but most of the staffs were recolonized after several months. The nature of antibiotic susceptibility was changed from multi-drugsusceptible to multi-drug-resistant. The most frequently contaminated objects were dressing carts, computer keyboards, bassinets and washbowls. In environmental cultures using the settle microbe count method, the colony counts were decreased significantly at the last study period compared with the first study period in the neonatal room, breastfeeding room, service room, and dressing room (P <0.05). Conclusion : Effective control of sustained MRSA transmission within an institution may require prompt identification, treatment, and monitoring of colonized and/or infected staffs. However, nasal decolonization therapy may induce multi-drugresistant MRSA infection and had no effect on decreasing the MRSA nasal carriage rate in our study. Other factors might be more important, such as improving staff education, increasing hand hygiene practices, and environmental sterilization for controlling MRSA infections.