• 한국식품저장유통학회지
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• 제15권4호
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• pp.491-496
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• 2008

총각김치의 신선도표시계 개발을 위하여 총각김치를 제조한 후 $20^{\circ}C,\;10^{\circ}C,\;4^{\circ}C$에서 저장하면서 총각김치의 발효 중 pH, 총산도, 총균수, 젖산균수, 환원당 측정 및 관능평가를 수행하였다. 모든 저장 온도에서 pH는 약간 증가하다가 발효가 진행됨에 따라 $4.2{\sim}4.3$까지 낮아졌고 저장 온도가 높을수록 감소속도가 빨랐다. 총산도는 $20^{\circ}C$ 에서 1일, $10^{\circ}C$에서 5일, $4^{\circ}C$에서 7일 이후 급격히 증가하는 경향을 보였다. 총균수와 젖산균수는 저장 온도 $20^{\circ}C$ 에서 4일, $10^{\circ}C$에서 10일, $4^{\circ}C$ 에서 30일 까지 증가했다가 이후 감소하였다, 관능평가 결과 총각김치의 가식기간은 저장 온도 $20^{\circ}C$에서 4일, pH 4.5까지, $10^{\circ}C$ 에서 10일, pH 4.4까지, 그리고 $4^{\circ}C$에서 30일, pH 4.3으로 판단된다. 본 연구결과 총각김치의 유통기한은 저장 온도에 따라 큰 차이를 보였으며 유통기한 설정을 위한 신선도표시계 개발에 있어서 한계 pH는 4.3으로 판단된다.

• 한국식품과학회지
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• 제33권1호
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• pp.94-99
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• 2001

전통 고추장의 품질개선을 위하여 고추장에 전통메주와 전통 메주에서 분리된 우수 균주를 접종한 고오지를 일정비율로 첨가하고 일부 시료는 가열처리하여 저장하면서 고추장의 미생물 및 효소역가를 분석하였다. 세균수는 전체적으로 발효 40일째 약간 증가하였으며 처리구간의 뚜렷한 차이는 없었고 곰팡이는 계속 감소하여 처리구에 따라 발효 40일 또는 60일 이후에는 검출되지 않았고 효모는 P-1 고오지 함량이 많은 처리구일수록 적은 수가 검출되었고, 열처리에 의해서 효모의 증식이 억제되었다. 고추장 숙성 중 발생한 가스의 누적량은 효모의 증식경향과 일치하였는데 전통메주 첨가시 가장 많았고 P-1 고오지 첨가시 가장 적었으며 열처리구는 발효기간 내내 가스가 전혀 발생되지 않았다. 고추장 숙성 중 효소는 ${\alpha}-amylase$ 경우 전체적으로 활성이 매우 낮았으며, ${\beta}-amylase$는 처리구에 따라 불규칙한 경향을 보이면서 전반적으로 전통메주 첨가구(CON)와 전통메주와 P-2 고오지 첨가구(MKP2)가 다른 처리구에 비하여 낮은 활성을 보였다. 산성 protease 활성도는 증가와 감소를 반복하다가 발효 100일째 활성이 최대였고, 중성 protease는 발효 60일까지 증가하다 점점 감소하였고 두 효소 모두 처리구간의 뚜렷한 차이는 없었다. 결과적으로 고추장에 선발 균주를 접종한 고오지를 첨가하였을 때 세균 및 곰팡이수, 효소역가는 전통 메주를 사용할 때와 뚜렷한 차이를 보이지 않은 반면 효모 생성과 가스 발생 억제에는 매우 효과적이므로 고추장 발효 관리의 한 수단으로 미생물 관리방법이 제안될 수 있다.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.667-675
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• 2021

Streptococcus agalactiae is an important bacterial pathogen and causative agent of diseases including neonatal sepsis and meningitis, as well as infections in healthy adults and pregnant women. Although antibiotic treatments effectively relieve symptoms, the emergence and transmission of multidrug-resistant strains indicate the need for an effective immunotherapy. Effector T helper (Th) 17 cells are a relatively newly discovered subpopulation of helper CD4⁺ T lymphocytes, and which, by expressing interleukin (IL)-17A, play crucial roles in host defenses against a variety of pathogens, including bacteria and viruses. However, whether S. agalactiae infection can induce the differentiation of CD4⁺ T cells into Th17 cells, and whether IL-17A can play an effective role against S. agalactiae infections, are still unclear. In this study, we analyzed the responses of CD4⁺ T cells and their defensive effects after S. agalactiae infection. The results showed that S. agalactiae infection induces not only the formation of Th1 cells expressing interferon (IFN)-γ, but also the differentiation of mouse splenic CD4⁺ T cells into Th17 cells, which highly express IL-17A. In addition, the bacterial load of S. agalactiae was significantly increased and decreased in organs as determined by antibody neutralization and IL-17A addition experiments, respectively. The results confirmed that IL-17A is required by the host to defend against S. agalactiae and that it plays an important role in effectively eliminating S. agalactiae. Our findings therefore prompt us to adopt effective methods to regulate the expression of IL-17A as a potent strategy for the prevention and treatment of S. agalactiae infection.

• Journal of Periodontal and Implant Science
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• 제48권4호
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• pp.261-271
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• 2018

Purpose: Few studies have examined periodontal pathogens from saliva samples in periodontally healthy young adults. The purposes of this study were to determine the prevalence of periodontopathic bacteria and to quantify periodontal pathogens in saliva samples using real-time polymerase chain reaction (PCR) assays in periodontally healthy Korean young adults under 35 years of age. Methods: Nine major periodontal pathogens were analyzed by real-time PCR in saliva from 94 periodontally healthy young adults. Quantification of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Peptostreptococcus anaerobius, and Eikenella corrodens was performed by DNA copy number measurement. Results: F. nucleatum and E. corrodens were detected in all subjects; the numbers of positive samples were 87 (92.6%), 91 (96.8%), and 90 (95.7%) for P. gingivalis, P. anaerobius, and C. rectus, respectively. Other pathogens were also detected in periodontally healthy subjects. Analysis of DNA copy numbers revealed that the most abundant periodontal pathogen was F. nucleatum, which was significantly more prevalent than all other bacteria (P<0.001), followed by P. anaerobius, P. gingivalis, E. corrodens, C. rectus, and T. denticola. There was no significant difference in the prevalence of each bacterium between men and women. The DNA copy number of total bacteria was significantly higher in men than in women. Conclusions: Major periodontal pathogens were prevalent in the saliva of periodontally healthy Korean young adults. Therefore, we suggest that the development of periodontal disease should not be overlooked in periodontally healthy young people, as it can arise due to periodontal pathogen imbalance and host susceptibility.

• 한국식품저장유통학회지
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• 제12권3호
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• pp.287-291
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• 2005

김치에 큰느타리버섯을 첨가하여 숙성시키면서 품질특성의 변화를 측정하였다. 버섯 첨가량에 따른 김치의 pH를 측정 한 결과 대조구보다 버섯첨가구의 pH가 전반적으로 약간 낮게 나타났으며, 적정산도는 pH와 반대로 버섯의 첨가량이 높을수록 적정산도가 높았다. 큰느타리버섯 첨가에 따른 김치의 총균수 및 유산균수는 숙성 18일경에 모두 최대치를 보였으며, 이후에는 조금 감소하였다. 특히 버섯 $30\%$ 처리구는 총균수 및 유산균수 모두에서 미생물 억제현상이 관찰되었다. 큰느타리버섯 첨가량에 따른 김치의 라디컬 소거능 및 총페놀함량은 첨가량에 비례하여 증가하였으며, 이는 버섯에 존재하는 항산화성 페놀성분에 의한 것으로 생각된다.

• BMB Reports
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• 제47권4호
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• pp.203-208
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• 2014

To gain insights into the effect of MexB gene under the short interfering RNA (siRNA), we synthesized 21 bp siRNA duplexes against the MexB gene. RT-PCR was performed to determine whether the siRNA inhibited the expression of MexB mRNA. Changes in antibiotic susceptibility in response to siRNA were measured by the E-test method. The efficacy of siRNAs was determined in a murine model of chronic P. aeruginosa lung infection. MexB-siRNAs inhibited both mRNA expression and the activity of P. aeruginosa in vitro. In vivo, siRNA was effective in reducing the bacterial load in the model of chronic lung infection and the P. aeruginosa-induced pathological changes. MexB-siRNA treatment enhanced the production of inflammatory cytokines in the early infection stage (P < 0.05). Our results suggest that targeting of MexB with siRNA appears to be a novel strategy for treating P. aeruginosa infections.

• 한국환경보건학회지
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• 제37권4호
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• pp.289-297
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• 2011

Objectives: To estimate the microbial contaminant load discharged from livestock farms, we randomly selected livestock farmers of cattle, swine, and fowl and collected bacterial strains from domestic animals' feces and compost samples. Recently, as multi-antibiotic-resistant bacteria and super bacteria showing resistance to a variety of antibiotics have been reported one after another, the ecological and health hazard of antibiotic-resistant bacteria is emerging as an important issue. Methods: Monitored indicator microorganism constituents were totak coliform (TC), fecal coliform (FC), and aerobic bacteria. The multi-antibiotic-resistant bacteria were identified from investigated indicator microorganisms by 16S rRNA sequencing. Results: By microbiological analysis, the largest population of aerobic bacteria ($1.5{\times}10^5$ CFU/g) was found in cattle fecal compost, and total coliforms ($1.1{\times}10^7$ CFU/g) and fecal coliforms ($1.0{\times}10^5$ CFU/g) were found primarily in swine fecal compost, while the lowest population was found in fowl fecal compost. Among the 67 strains separated from aerobic bacteria, five strains expressing high antibiotic resistance were selected in each sample. We found the multi-antibiotic resistant strains to be Shigella boydii, Staphylococcus lentus, Acinetobacter sp. and Brevibacterium luteolum. Conclusions: These results suggest that increasing numbers of multi-antibiotic-resistant bacteria in the environment have a close relation to the reckless use of antibiotics with livestock.

• Membrane and Water Treatment
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• 제9권3호
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• pp.181-188
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• 2018

A sidestream contains the filtrate or concentrate from the belt filter press, filter backwash and supernatant from sludge digesters. The sidestream flow, which heads back into the sewage treatment train, is about 1-3% less than the influent flow. However, the sidestream can increase the nutrient load since it contains high concentrations of phosphorus and nitrogen. In this study, the removal of PO4-P with organic matter characteristics and bacteriological changes during the sidestream treatment via ladle furnace (LF) slag was investigated. The sidestream used in this study consisted of 11-14% PO4-P and 3.2-3.6% soluble chemical oxygen demand in influent loading rates. LF slag, which had a relatively high $Ca^{2+}$ release compared to other slags, was used to remove $PO_4-P$ from the sidestream. The phosphate removal rates increased as the slag particle size decreased 19.1% (2.0-4.0 mm, 25.2% (1.0-2.0 mm) and 79.9% (0.5-1.0 mm). The removal rates of dissolved organic carbon, soluble chemical oxygen demand, color and aromatic organic matter ($UV_{254}$) were 17.6, 41.7, 90.2 and 77.3%, respectively. Fluorescence excitation-emission matrices and liquid chromatography-organic carbon detection demonstrated that the sidestream treatment via LF slag was effective in the removal of biopolymers. However, the removal of dissolved organic matter was not significant during the treatment. The intact bacterial biomass decreased from $1.64{\times}10^8cells/mL$ to $1.05{\times}10^8cells/mL$. The use of LF slag was effective for the removal of phosphate and the removal efficiency of phosphate was greater than 80% for up to 100 bed volumes.

• 한국식품영양과학회지
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• 제30권2호
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• pp.210-214
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• 2001

팽이버섯을 첨가한 김치를 만든 다음 숙성하면서 품질특성의 변화를 측정한 결과 팽이버섯을 5% 첨가한 시험구는 다른 시험구에 비하여 pH가 낮았다. 또한 숙성 11일 이후에는 팽이바섯을 첨가한 시험구의 pH가 대조구보다 낮았으나 적정산도의 값도 낮게 나타나 일반적인 pH와 적정산도의 관계와는 다소 다른 경향을 보였다. 김치를 담근 직후에는 팽이버섯의 첨가량이 많을수록 총균수가 높은 것으로 나타났다. 숙성중의 총균수와 유산균수는 5일에 최대값을 보였으며, 총균수 및 유산균수는 $10^{83}(2.0{\times}10^{8})$ 부근으로 나타났고, 팽이버섯 첨가에 따른 차이는 거의 보이지 않았다. 숙성 5일까지는 팽이버섯을 첨가한 시험구가 대조구보다는 유리 래디칼을 소거할 수 있는 능력이 낮았으나 숙성 11일 이후에는 팽이버섯을 첨가한 김치의 래디칼 소거능이 대조구보다 높은 것으로 나타났다. 숙성 15일경부터는 대조구보다 팽이버섯을 시험구의 적색도가 더 높았으며, 관능검사 결과 팽이비섯을 5% 첨가한 시험구가 색과 맛의 평가에 가장 높은 점수를 얻었다.

• 한국환경보건학회지
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• 제40권3호
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• pp.245-254
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• 2014

Objectives: This study was performed to investigate hand washing awareness of females and load of indicator bacteria on their hands. This study focused on the variation according to their age. Methods: A self-administered questionnaire survey and bacterial analysis of indicator bacteria were carried out for 100 Korean women in their age from 20 s to 60 s. Hand samples were collected through a modified glovejuice method. Results: In the survey, significant difference (p < 0.05) was found among the age groups in the use of hand washing agents. The levels of aerobic colony count (ACC) were the highest in both hands among the 20s (p < 0.05). The levels of Escherichia coli were higher in both hands in their 20s and 30s. No significant difference was found in the levels of Staphylococcus aureus and Salmonella spp. However, the positive rates of S. aureus (left hand, 37.5~47.1%; right hand, 58.5~62.5%) and Salmonella spp. (left hand, 25.0~52.9%; right hand, 37.5~64.7%) were higher in the hands of the 20s and 30s, and then showed decreasing trend according to increase of age. The effect of hand washing frequency on the ACC level of hands was significant (p < 0.001). Conclusions: These results indicate that there was no remarkable difference of hand hygiene awareness among female age groups. The detection of S. aureus and Salmonella spp. on the hands of some females in each age group revealed poor hand hygiene practices. The significant effect of hand washing frequency on the ACC level suggests that frequent hand washing is helpful to reduce hand contamination.