• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.287-293
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• 2011

The purpose of this study was to isolate and characterize fungal deteriogens, which induce discoloration of the cement tunnel, and calcite forming bacteria (CFBs), which have antifungal activity against fungal deteriogens. Isolation of mold, bacteria and yeast was performed using several solid media and partially identified using internal transcribed spacer (ITS); 5.8S rRNA gene sequencing and 16s rDNA sequencing. A total of 19 microbial strains were identified with the most widely distributed fungal strain being Cladospirum sphaerospermum. In addition, five bacteria derived from the tunnel were identified as CFBs. Amongst the latter, Bacillus aryabhatti KNUC205 exhibited antifungal activity against Cladospirum sphaerospermum KNUC253 and Aspergillus niger KCTC6906 as concentrated filtered supernatants.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1574-1582
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• 2014

Bacteria recognize changes in their population density by sensing the concentration of signal molecules, N-acyl-homoserine lactones (AHLs). AHL-mediated quorum sensing (QS) plays a key role in biofilm formation, so the interference of QS, referred to as quorum quenching (QQ), has received a great deal of attention. A QQ strategy can be applied to membrane bioreactors (MBRs) for advanced wastewater treatment to control biofouling. To isolate QQ bacteria that can inhibit biofilm formation, we isolated diverse AHL-degrading bacteria from a laboratory-scale MBR and sludge from real wastewater treatment plants. A total of 225 AHL-degrading bacteria were isolated from the sludge sample by enrichment culture. Afipia sp., Acinetobacter sp. and Streptococcus sp. strains produced the intracellular QQ enzyme, whereas Pseudomonas sp., Micrococcus sp. and Staphylococcus sp. produced the extracellular QQ enzyme. In case of Microbacterium sp. and Rhodococcus sp., AHL-degrading activities were detected in the whole-cell assay and Rhodococcus sp. showed AHL-degrading activity in cell-free lysate as well. There has been no report for AHL-degrading capability in the case of Streptococcus sp. and Afipia sp. strains. Finally, inhibition of biofilm formation by isolated QQ bacteria or enzymes was observed on glass slides and 96-well microtiter plates using crystal violet staining. QQ strains or enzymes not only inhibited initial biofilm development but also reduced established biofilms.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.4
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• pp.322-328
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• 2005

Oral and maxillofacial infections are most commonly odontogenic in origin. The present study was implemented for patients with oral and maxillofacial infections in order to determine what differences were present in cultured bacteria, depending upon the different types of infection. For the present study, the epidemiological characteristics, the state of infection, and the results of the pus culture and antibiotic susceptibility tests were analyzed for the 159 cases where pus culture tests were performed. The patients were treated at the Oral and Maxillofacial Surgical Department of Chonnam National University Hospital during an 18-months period from March 2003 to August 2004. Among the total 159 pus culture specimens, bacteria were cultured in 111 cases (69.8%). In the 111 pus culture specimens, Streptococcus species, Neisseria species, and Staphylococcus species were cultured from 69 cases (51.1%), 21 cases (15.6%), and 15 cases (11.1%), respectively and were determined to be bacterial strains the predominant bacteria responsible for oral and maxillofacial infectious diseases. Twenty four cases (15.1%) among the 159 specimens showed mixed infections. The mostly isolated bacteria from each of the space abscess, dentoalveolar abscess, inflammatory cyst, and pericoronitis cases were the Viridans streptococci. There was little relevance between the type of infection and the type of cultured bacteria. Antibiotic susceptibility tests showed a high level of susceptibility to teicoplanin(100%), vancomycin(100%), chloramphenicol(96.4%), ofloxacin(88.3%), imipenem(83.3%), erythromycin(82.5%) and a low susceptibility to cefazolin(40.0%), oxacillin(44.7%), ampicillin(49.4%), penicillin(51.1%). These results indicate that there was no significant difference among the cultured bacteria depending on the type of infections and their susceptibility to cephalosporin and penicillin G was low.

• Journal of the Korean Society of Food Culture
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• v.29 no.3
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• pp.286-297
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• 2014

This study was conducted to evaluate the growth of lactic acid bacteria and quality characteristics of Baechu kimchi prepared with four types of salt (Solar salt, Flower salt, Hanju salt, and Roasted salt) at two different concentrations (10, 15%) during storage. The quality characteristics of kimchi were examined by investigating acid production, growth of lactic acid bacteria, sensory properties, salinity, texture, and color characteristics. Baechu kimchi was fermented for 18 days at $10^{\circ}C$. The pH and total acidity did not change during storage according to type and concentration of salt. Growth of lactic acid bacteria was not affected by type of salt, whereas it was inhibited at 15% salt concentration after 9 days of fermentation. In the quantitative descriptive analysis of sensory properties, kimchi prepared with 10% salt showed significantly higher scores in term of overall acceptability (p<0.05). Meanwhile, there was no significant difference by type of salt. For texture characteristics, hardness of kimchi prepared with 10% salt was significantly higher than that with 20% salt. For color characteristics, L value (brightness) and b values (yellowness) of kimchi prepared with 10% salt increased during fermentation, whereas a value (redness) did not change by type and concentration of salt. The results of this study show that there were no considerable differences in quality characteristics of Baechu kimchi prepared with various types and concentrations of salt. However, Solar salt resulted in more favorable sensory properties and salinity of kimchi than any other types. Further, kimchi prepared with 10% salt showed significantly higher scores in terms of overall acceptability, growth of lactic acid bacteria, salinity, texture, and color characteristics.

• Korean Journal of Pharmacognosy
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• v.24 no.3
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• pp.235-243
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• 1993

We have concerned the action of traditional herbal medicine (THM) to relate with longevity, aging and immune, etc. Espically, we have studied on the role of intestinal bacteria on THM such as Nokyongdaebo-Tang, Bojungikgi-Tang, Ikgibohyul-Tang, Bobyulansin-Tang and Bojanggunbi-Tang. Samples of the p.o. administration of 2 g/kg for 2 weeks did not find the change transaminase activities in mice. But, Nokyongdaebo-Tang and Bojanggunbi-Tang elevated the serum glucose levels and Bojungikgi-Tang elevated the total cholesterol levels in mice. ${\beta}-Glucuronidase$ activities in mice faeces are decreased by the treatment of Nokyongdaebo-Tang, Bojungikgi-Tang, Ikgibohyul-Tang and Bojanggunbi-Tang, but increased by the treatment of Bohyulansin-Tang. Number of lactic acid bacteria in mice faeces are increased by the treatment of Nokyongdaebo-Tang, Bojungikgi-Tang, lkgibohyul-Tang, Bohyulansin-Tang and Bojanggunbi-Tang. We recognized that ${\beta}-glucuronidase$ activities and the number of lactic acid bacteria were remarkably decreased by the pretreatment of antibiotics in mice. Nokyongdaebo-Tang and Ikgibohyul-Tang at the p.o. administration of 2 g/kg significantly increased the ${\beta}-glucuronidase$ activities and Bojungikgi-Tang and Bohyulansin-Tang remarkably increased the number of lactic acid bacteria in antibiotics pretreated mice.

• Computers and Concrete
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• v.27 no.4
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• pp.319-332
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• 2021

The performance of gene expression programming (GEP) in predicting the compressive strength of bacteria-incorporated geopolymer concrete (GPC) was examined in this study. Ground-granulated blast-furnace slag (GGBS), new bacterial strains, fly ash (FA), silica fume (SF), metakaolin (MK), and manufactured sand were used as ingredients in the concrete mixture. For the geopolymer preparation, an 8 M sodium hydroxide (NaOH) solution was used, and the ambient curing temperature (28℃) was maintained for all mixtures. The ratio of sodium silicate (Na2SiO3) to NaOH was 2.33, and the ratio of alkaline liquid to binder was 0.35. Based on experimental data collected from the literature, an evolutionary-based algorithm (GEP) was proposed to develop new predictive models for estimating the compressive strength of GPC containing bacteria. Data were classified into training and testing sets to obtain a closed-form solution using GEP. Independent variables for the model were the constituent materials of GPC, such as FA, MK, SF, and Bacillus bacteria. A total of six GEP formulations were developed for predicting the compressive strength of bacteria-incorporated GPC obtained at 1, 3, 7, 28, 56, and 90 days of curing. 80% and 20% of the data were used for training and testing the models, respectively. R2 values in the range of 0.9747 and 0.9950 (including train and test dataset) were obtained for the concrete samples, which showed that GEP can be used to predict the compressive strength of GPC containing bacteria with minimal error. Moreover, the GEP models were in good agreement with the experimental datasets and were robust and reliable. The models developed could serve as a tool for concrete constructors using geopolymers within the framework of this research.

• Journal of Veterinary Science
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• v.23 no.1
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• pp.6.1-6.8
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• 2022

Background: With limited information available, the association among urinary tract infections, urease-producing bacteria and the presence of magnesium ammonium phosphate (MAP) urolithiasis in canines in Thailand requires more study. Objectives: This study aimed to investigate the association between demographic characteristics of canines and the presence of MAP urolithiasis in canines, and to evaluate antimicrobial susceptibility patterns of bacteria isolated from canine uroliths. Methods: A total of 56 canines admitted for treatment with surgical removal of uroliths were recruited. Demographic characteristics and clinical chemistry data were recorded. Bacteria isolated from the removed uroliths were identified. Chemical compositions of the uroliths were analyzed by Fourier transform infrared spectrometer. Potential risk factors were determined with univariable and multivariable logistic regression analyses. Results: Of 56 canine urolithiasis, bacteria were isolated from uroliths of 38 canines (27 MAP and 11 non-MAP) but not from uroliths of 18 canines (5 MAP and 13 non-MAP). The most common bacteria found in nidus of MAP uroliths was Staphylococcus pseudintermedius (approximately 51%). An antimicrobial resistance was frequently found in Staphylococci isolates (42.86%). Multivariate logistic regression analysis showed that the predictors of MAP urolith in canine urolithiasis were being female (p = 0.044; adjusted odds ratio [OR], 10.22; 95% confidence interval [CI], 1.06-98.24) and the positive urolith culture (p = 0.012; adjusted OR, 8.60; 95% CI, 1.60-46.30). Conclusions: Our results indicate that S. pseudintermedius (a urease-producing bacterium) is the major causative bacteria of MAP uroliths. A positive urolith culture and being female are risk factors of MAP urolithiasis in canines.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.110-119
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• 2024

Background: The Mae Kha Canal is one of Chiang Mai's most important waterways. It supports local agriculture, irrigation, and transportation as well as provides stormwater drainage to prevent floods. Due to the unregulated rapid urbanization of the city and lack of efficient waste and wastewater management systems over the past few decades, the canal has become heavily polluted. This study aimed to evaluate the water quality of Mae Kha canal through assessment of the physico-chemical water quality and coliform bacteria. Moreover, benthic macroinvertebrates were samples and assessed using the Biological Monitoring Working Party (BMWP^Thai) and Average Score Per Taxon (ASPT^Thai) as biological indices. Results: The physico-chemical showed low dissolved oxygen levels, high levels of ammonia and phosphates, and elevated levels of biochemical oxygen demand, indicating that the water quality had significantly deteriorated. The canal was found to be heavily polluted, with most sites falling into the polluted to very heavily polluted. Coliform bacteria analysis revealed alarmingly high levels of total coliform bacteria and fecal coliform bacteria in the canal. The BMWP^Thai and ASPT^Thai scores indicated poor to very poor water quality. Conclusions: The physico-chemical and coliform bacteria indicated that the water quality of the Mae Kha canal had significantly deteriorated. The biological indices also indicated the poor to very poor water quality. This study underscores the urgent need for comprehensive remediation efforts, emphasizing strategic planning, investment, and community engagement to revive the canal's ecological health and water quality.

• Economic and Environmental Geology
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• v.43 no.3
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• pp.223-233
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• 2010

The effects of extracellular polymeric substances (EPS) of Pseudomonas aeruginosa on adsorption and redox state alteration of dissolved As, Cr and U were investigated through batch experiments. Surfaces of bacterial cells were either vigorously washed or unwashed. Solutions of As(V), Cr(VI) and U(VI) were inoculated with the bacterial cells under no nutrient condition, and total aqueous concentrations and redox state alteration were monitored over time. No As adsorption occurred onto bacteria or EPS; however, unwashed bacteria reduced about 60% As(V) to As(III). Unwashed bacteria also led to removal of 45% total dissolved Cr and reduction of 64% Cr(VI). About 80% U(VI) was removed from solution with unwashed bacteria as well. Such electrochemical reduction of the elements was likely due to reducing capacity of EPS itself or detoxifying reduction of the bacteria which kept their viability under protection of EPS. The results indicated that bacterial biofilm may significantly control the redox state and subsequent mobility of As, Cr and U in natural geologic settings.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.96-101
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• 2013

This study was carried out to investigate the changes in antioxidant activity, and the isoflavone and free amino acid content in fermented tofu of the ingredients of kimchi (red pepper, garlic, ginger, and anchovies) and lactic acid bacteria (Pediococcus acidilactici KL-6) during 24 weeks of fermentation at $20^{\circ}C$. The total polyphenol content of various types of fermented tofu such as the control (tofu with kimchi ingredients mixture), tofu and kimchi ingredients with lactic acid bacteria (TL), and tofu in pre-fermented kimchi ingredients with lactic acid bacteria (TPL) ranged from 156.34 to 165.17 mg/g, showing that TPL was significantly higher in terms of fermentation time (6 weeks) compared to others. The DPPH free radical scavenging activity of TPL (84.11%) was higher than that of the control (76.68%) and TL (78.95%) after 12 weeks fermentation at $20^{\circ}C$. The changes of nitrite scavenging activity and SOD-like activity in the tested tofu showed the same tendency as the DPPH free radical scavenging activity during 14 weeks fermentation TPL showed statistically significant levels of increased antioxidant activity, so we compared the isoflavone and free amino acid content. The isoflavone and free amino acid content of TPL was 2.34 mg/g and 20.81 mg/g after 14 weeks fermentation, respectively.