• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.653-658
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• 2008

The bacteria responsible for the reduction of ammonia concentration in a food-wastewater treatment facility were isolated and their characteristics were analyzed. The isolated bacteria were closely related to the bacteria belonging to genus Citrobacter, Enterobacter, Buttiauxella, Shigella, and Aeromonas, which were found in gut of animals, indicating the isolated bacteria may come from the butchery-byproduct of pigs which is the main component of wastewater. When we monitored the concentration of nitrite and nitrate in the process, it was relatively constant, indicating the isolated bacteria reduce ammonia concentration through ammonia assimilation. Based on the removal efficiency of ammonia by the isolated bacteria, we concluded that they play a role in the reduction of odorous compounds.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1333-1340
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• 2016

The main objective of this study was to investigate whether Lactobacillus rhamnosus GG (LGG) ameliorated the effects of Citrobactor rodentium infection in Toll-like receptor 2 (TLR2) knockout (KO) and TLR4 KO mice, as well as in wild-type C57BL/6 (B6) mice. TLR2 KO, TLR4 KO, and B6 mice were divided into three groups per each strain. Each group had an uninfected control group (n = 5), C. rodentium-infected group (n = 8), and LGG-pretreated C. rodentium-infected group (n = 8). The survival rate of B6 mice infected with C. rodentium was higher when pretreated with LGG. Pretreatment with LGG ameliorated C. rodentium-induced mucosal hyperplasia in B6 and TLR4 KO mice. However, in C-rodentium-infected TLR2 KO mice, mucosal hyperplasia persisted, regardless of pretreatment with LGG. In addition, LGG-pretreated B6 and TLR4 KO mice showed a decrease in spleen weight and downregulation of tumor necrosis factor alpha, interferon gamma, and monocyte chemotactic protein 1 mRNA expression compared with the non-pretreated group. In contrast, such changes were not observed in TLR2 KO mice, regardless of pretreatment with LGG. From the above results, we conclude that pretreatment with LGG ameliorates C. rodentium-induced colitis in B6 and TLR4 KO mice, but not in TLR2 KO mice. Therefore, LGG protects mice from C. rodentium-induced colitis in a TLR2-dependent manner.

• The Korean Journal of Food And Nutrition
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• v.9 no.1
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• pp.29-36
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• 1996

Naengmyon is a Korean buckwheat noodle with chilld broth, and the juice of dongchimi, a Korean radish pickle fermented with wild lactic acid bacteria, has been used as the broth for naengmyon traditionally. The purpose of this study was to demonstrate the inhibitory effect of dongchimi-juice against coliform bacteria in model system of naengmyon-broth. Dongchimi-juice was made from radish juice by the cultivation of lactic acid bacteria which had been isolated from kimchi. Three types of naengmyon-broth, beef-broth type, dongchimi-juice type and the mixed type, were made as model systems, and then the changes in viable cell counts of seven coliform bacteria, Klebsiella planticola Bo2, X. terrigena CO8, K. pneumoniae DOI, K. ozaenae DO4, Enterobacter sp. AO2, Enterobacter sp. CO7, Citrobacter sp. BO7 and Escherichia sp. DO3, which had been added to each type of naengmyon-broth in advance, were investigated during storage at 3$0^{\circ}C$ All coliforms grew rapidly in naengmyon-broth of beef-broth type, while none grew in dongchimi-juice type or in the mixed type. All coliforms died out far more rapidly in dongchimi-juice type than in mixed type. The decreasing slopes of Citrobacter sp. Bo7, K. planticola BO2, X. terrigena CO8 and K. ozaenae DO4 were more steep than those of the rest. It was thought that the preparation method of Korean traditional naengmyon such as dongchimi-naengmyon or Pyongyang style-naengmyon, which uses oxy dongchimi-) juice or the mixture of dongchimi-juice and beef-broth, would be very effective for preventing the growth of coliform bacteria from naengmyon.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.684-689
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• 2005

In order to evaluate the in vitro synergic effect of Mahwangyounpae-tang which was a traditional poly-herbal formula has been used in the treatment of respiratory diseases in oriental medicine, and quinolone antibiotics, ciprofloxacin (CPFX), the minimal inhibitory concentration (MIC), $MIC_{50}$ and MIC90 of single use of quinolones and concomitant treatment with Mahwangyounpae-tang against 5 strains of aerobic gram negative bacteria, Escherichia coli, Klebsiella peumoniae, Hemophilus influenzae, Citrobacter freundii and Pseudomonas aeruginosae. The obtained results were as follows : In the case of aerobic gram negative bacteria, the MIC, $MIC_{50}$ and $MIC_{90}$ against Klebsiella peumoniae and Pseudomonas aeruginosae was significantly decreased in concomitant treated groups with Mahwangyounpae-tang compared to those of single treated groups of CPFX, respectively. However, no significant changes were demonstrated against Echerichia coli, Hemophilus influenzae and Citrobacter freundii. According to these results, it is considered as the in vitro antibacterial activity of CPFX was dramatically increased by concomitant use of Mahwangyounpae-tang against some strains of aerobic gram negative bacteria and the increase and selectivity of antibacterial activities against strains were chosen by the selectivity of Mahwangyounpae-tang not CPFX activity.

• Advances in Traditional Medicine
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• v.5 no.3
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• pp.246-250
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• 2005

A number of species of the genus Centaurea (Family: Asteraceae), distributed in various parts of Asia, Europe and North America, have been used in traditional plant-based medicine and reported to possess various medicinal properties. As part of our continuing evaluation of plants from the genus Centaurea for their phytochemistry and biological activities, the dichloromethane (DCM) and methanol (MeOH) extracts of the seeds of Turkish Centaurea species, C. bornmuelleri, C. huber-morathii and C. schiskinii, were screened for antioxidant and antibacterial activities. Among the three species, C. huber-morathii displayed the most prominent antibacterial activity. Both the MeOH and DCM extracts of this plant showed activity against Citrobacter freundii, Enterococcus faecalis and Salmonella goldcoast with the MIC values within the range of $1\;{\times}\;10^{-2}\;to\;1\;{\times}\;10^{-3}\;mg/ml$. The MeOH extract of C schiskinii showed activity $(MIC\;=\;1\;{\times}\;10^{-1}\;mg/ml)$ against Citrobacter freundii and Staphylococcus aureus. While the DCM extract of C. bornmuelleri was only active against Staphylococcus aureus $(MIC\;=1\;{\times}\;10^{-2}\;mg/ml)$, the MeOH extract did not show any inhibitory activity at test concentrations. The DCM and MeOH extracts of all three species demonstrated good degree of antioxidant property in the DPPH assay with the $RC_{50}$ values ranging from $72\;{\times}\;10^{-2}\;to\;31{\times}\;10^{-3}\;mg/ml$. Among these extracts, the MeOH extract of C. hubermorathii was the most active antioxidant extract $(MlC\;=\;31\;{\times}\;10^{-3}\;mg/ml)$.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.379-383
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• 1988

To evaluate the treatability of activated sludge induced by benzene with microorganisms, isolation and characterization of benzene-degrading microorganisms were carried out. Six bacterial isolates from the activated sludge were identified ; Pseudomonas fluorescens, Enterobacter agglomerans, Enterobacter cloacae, Klebsiella oxytoca, Citrobacter freundii and Klebsiella pneumoniae. P. fluorescens degraded 55% of benzene contained in the medium as a sole carbon source, E. cloacae 24%, E. agglomerans 41%, and K. oxytoca 32%. Optimal temperature, pH and benzene concentration for growth of P. fluorescens appeared to be 31$^{\circ}C$, pH 7.0, and 300mg benzene per liter. When the P. fluorescens was dominant in the activated sludge induced by benzene, the indicator protozoa was Aspidisca sp. When concentration of benzene was about 387mg per liter, the growths of Aspidisca sp. and Litonotus sp. were high. Protozoa, Litonotus sp. and Vorticella sp. did not grow over 1600mg of benzene per liter.

• Korean Journal of Microbiology
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• v.33 no.2
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• pp.92-96
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• 1997

The 6.8 kb Xhol fragment of chromosomal ONA of Pseudomonas sp. 0177 contains the phnDEFG genes involved in the degradation of polyaromatic hydrocarbons and chlorinated aromatics. Here, we report the nucleotide sequence of the ORF encoding a polypeptide consisted of 143 amino acids with a Mr of 13,859. The nucleotide sequence of the ORF is 99% and 68.6% identical to the downstream region of catE of Sphingomonas sp. strain HV3 and the ORF between xylE and xylG of Sphingomonas yanoikuyae Bl, respectively. The deduced amino acid sequence of the PhnF has 62.3% identity with the amino acid encoded hy orfY region of Citrobacter freundii DSM30040. We now confirm that the ORF is located between the catechol 2,3-dioxygenase (C230), phnE, and 2-hydroxymuconic semialdehyde dehydrogenase (2HMSO), phnG.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.841-848
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• 2004

Rapid detection of viable Salmonella in pasteurized milk is important to protect public health from food poisoning. Reverse transcriptase-polymerase chain reaction(RT-PCR) is recognized as a molecular genetical method to differentiate between live and dead bacteria The RT-PCR in this study was designed to detect specifically viable Salmonella in milk by using the primers whose nucleotide sequences were determined based on fimA gene which encodes the submit of type 1 fimbriae. Treatment of RNA preparation with RNase-free DNase was adequate enough to destroy DNA, which may otherwise be amplified in the RT PCR Seven strains of Salmonella were detected in the RT-PCR but Escherichia coli, Shigella sonnei, Citrobacter freundii, and Klebsiella pneumoniae were not. $10^7/ml$ and $10^6/ml$ of dead Salmonella which were heat-treated in milk were detectable by using the RT-PCR but $10^5{\sim}10/ml$ of the dead bacteria were not. The sensitivity of the RT-PCR in detecting viable Salmonella was 100 cells/ml.

• Journal of Soil and Groundwater Environment
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• v.19 no.2
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• pp.38-43
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• 2014

In this study, we evaluated the methylene blue (MB) adsorption potential of non-treated and UV-C pretreated bacterial biomass from aqueous solution. The UV-C pretreatment denature the biomass and has increased overall functional groups when compared to non-treated biomass. The biosorbent was exposed to various pH, biomass dose, and contact time. The results showed that the dried and UV-C pretreated biomass effectively removed MB within 30 min. Dried and UV-C pretreated biomass of Bacillus pseudomycoides JH 2-2 showed a adsorption of 858.2 and 1072.4 mg/g at optimum conditions (pH: 9.0, contact time: 30 min, biomass dose: 1 g/L). Similarly, dried and UV-C pretreated biomass of Citrobacter freundii JH 11-2 showed an adsorption 868.3 and 954 mg/g at optimum conditions (pH: 9.0, contact time: 10 min, biomass dose: 1.5 g/L). The changes in the functional groups of UV-C pretreated biomass could be responsible for enhanced adsorption of MB. The results obtained have shown that non-treated and UV-C pretreated biomass has a high adsorption capacity for MB dye and can be used as a low-cost biosorbent in wastewater treatments.

• Journal of fish pathology
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• v.35 no.1
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• pp.77-92
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• 2022

Aquaculture development is based on the ideas of increasing production while reducing economic losses. Bacterial diseases are the leading source of fish cases. Citrobacter freundii has been linked to septicemia and mortality all over the world. In the current study, the cause of mortality in O. niloticus was C. freundii MW279218. External hemorrhages were seen on the affected fish, as well as paleness in the liver and kidney congestion. C. freundii MW279218 had a median lethal dosage of 1.5×10⁵ CFU/mL. Zinc oxide and zinc oxide nanoparticles (ZnO-NPs) were tested for their biocidal effectiveness against C. freundii MW279218. The lethal effect of ZnO-NPs for C. freundii MW279218 was 100% when compared to zinc oxide compound, and the inhibition zone width was 2.31.1mm at the highest tested concentrations (70 mg/L) compared to the lowest (35 and 45 mg/L, respectively). Fish were fed three different diets for 28 days: diet 1 (no additives), diet 2 (100 mg of ZnO-NPs/kg of feed), and diet 3 (200 mg of ZnO-NPs/kg of feed). Organs were also collected for histopathology 96 hours after injection (P<0.05). In the groups given 200 mg of ZnO-NPs, there was 10% mortality and 80% RPS. The group fed 100 mg of ZnO-NPs/kg, on the other hand, had 20% mortality and 60% RPS, compared to 50% mortality in the control positive group. Histopathological examinations demonstrated significant alterations in the control positive group and mild lesions in the hepatopancreas of the groups administered 100 mg ZnO-NPs/kg of feed. The groups fed 200 mg of ZnO-NPs/kg diet, on the other hand, showed no histological alterations. ZnO-NPs were found to be effective in the up regulation of both IL-10 and complement 5 immune-related genes.