• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2002년도 추계학술대회
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• pp.22-26
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• 2002

There are a number of ways in which environmental microbiology and microbial ecology will benefit from DNA micro array technology. These include community genome arrays, SSU rDNA arrays, environmental functional gene arrays, population biology arrays, and there are clearly more different applications of microarray technology that can be applied to relevant problems in environmental microbiology. Two types of the applications, bacterial identification chip and functional gene detection chip, will be presented. For the bacterial identification chip, a new approach employing random genome fragments that eliminates the disadvantages of traditional DNA-DNA hybridization is proposed to identify and type bacteria based on genomic DNA-DNA similarity. Bacterial genomes are fragmented randomly, and representative fragments are spotted on a glass slide and then hybridized to test genomes. Resulting hybridization profiles are used in statistical procedures to identify test strains. Second, the direct binding version of microarray with a different array design and hybridization scheme is proposed to quantify target genes in environmental samples. Reference DNA was employed to normalize variations in spot size and hybridization. The approach for designing quantitative microarrays and the inferred equation from this study provide a simple and convenient way to estimate the target gene concentration from the hybridization signal ratio.

• 설비공학논문집
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• 제17권6호
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• pp.581-586
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• 2005

Recently, the use of UVGI system has been increasing in both medical and nonmedical buildings for the control of environmental microorganisms. In the present study, irradiance performance test of UVC lamp was carried out and indoor air sterilization effect of UV ray for preventing transimission of air borne contagion was investigated by using manufactured UVC air sterilizer. Experimental results show that the effective irradiance of UVC lamp is strongly dependent on air velocity and temperature in irradiance performance test. An individual microbiological killing effectiveness experiment also shows that the average kill rate of two microbiological samples such as bacteria and fungus is about $92\%$ by using manufactured UVC air sterilizer. Additionally irradiance performance experimental results also show that the ballast is very important factor to keep up irradiance performance of UVC lamp.

• 한국산학기술학회논문지
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• 제15권7호
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• pp.4310-4317
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• 2014

본 연구는 수작업 떡류의 HACCP(Hazard Analysis Critical Control Point)시스템 적용을 위한 목적으로 하였다. 본 실험에 사용된 시료는 떡의 주원료, 작업장 시설, 도구와 작업자는, 2012년 9월 12일~2013년 2월 13일까지 서울시 용산구 서계동 소재에 있는 KB 업체에서 제공받았다. 제조공정도는 일반적인 떡류 제조업체의 제조공정을 참고로 작성하였다. 제조 공정도는 원료 농산물(맵쌀, 찹쌀, 잣 등), 부재료(분말원료), 용수와 포장재료의 입고, 보관, 정선 및 계량, 세척, 불림, 탈수, 분쇄, 주재료 혼합, 익반죽, 수작업 성형, 증자, 냉각, 절단, 내포장, 금속검출, 외포장, 보관 및 출하공정으로 작성하였다. 원료 농산물의 미생물학적 위해요소 분석결과는 Table 1과 같다. 본 연구결과 증자공정 후의 떡과 원재료의 미생물검사 결과는 안전한 것으로 보인다. 하지만, 체계적인 세척 및 소독을 실시하여 미생물학적 위해를 감소시키고 작업자 위생교육 등을 통하여 개인위생개념 향상과 작업장의 미생물 관리가 함께 이루어져야 할 것으로 여겨진다.

• Food Science and Biotechnology
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• 제16권6호
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• pp.868-872
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• 2007

The microbiological and chemical identification of antibiotic residues was attempted for livestock and seafood products including pork (n=34), beef (n=34), chicken (n=32), flatfish (n=37), armorclad rockfish (n=36), and sea bream (n=27). The meat (n=100) and seafood (n=100) samples were collected from 9 markets in 5 major Korean cities. Antibiotic substances were identified from the classes of tetracyclines, macrolides, penicillins, aminoglycosides, polyethers, peptides, sulfonamides, quinolones, chlorampenicols, and novobiocins using a microbiological assay, the Charm II test and high performance liquid chromatography (HPLC) with ultra violet (UV) and fluorescence detectors. The results showed that 2 tetracyclines (oxytetracycline and tetracycline) and 3 quinolones (ciprofloxacin, norfloxacin, and enrofloxacin) were detected in 4 samples of flatfish among all 100 seafood samples tested. No antibiotic residues were detected in the 100 livestock product samples tested. The amounts (min-max, mg/kg) of the residual antibiotics were as follows; tetracycline 0.78-0.85, oxytetracycline 0.49-0.74, ciprofloxacin 0.09-0.83, norfloxacin 0.01-0.21, enrofloxacin 0.12-2.98. These data indicate that the total detection rate of antibiotics in livestock and seafood products was approximately 2%.

• 한국축산식품학회지
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• 제18권1호
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• pp.63-74
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• 1998

Recently the high outbreaks of intestinal disease caused by the consumption of frozen dairy foods containing pathogenic bacteria has generated considerable interest in the causative agent such as Listeria monocytogenes and E. coli O157:H7. This study was carried out to detect the above pathogens and compare the microbiological qualities of three commercial forzen yogurt products. The main results obtained were as follows. L. monocytogenes coliforms and E. coli O157:H7 were not detected in the total of seven frozen yogurt samples. For microbiological qualities the viable lactic counts of products manufactured by FA company were about 2.9$\times$108 -1.6$\times$109cfu/ml 1.7$\times$106 cfu/ml for FB's and 1.2$\times$106 cfu/ml for FC's The PH values of FA's FB's and FC's products was in the range of pH 4.1~5.3 and the values of FA's were 4.1~4.6 compared by the pH 5.2~5.3 of FB's and FC's products. During refrigeration of the test samples the survival rates of L. monocytogenes spiked into thawed frozen yogurt sample(FA's FB,s and FC's) were 0.55% 15.61% and 16.89% respectively. On the other hand E. coli O157:H7 and L. monocytogenes were 12.4% and 25.0% for FA's 10.8% and 20.8% for FB's and 10.26% and 22.7% for FC's under 37$^{\circ}C$ storage, As the results described above each frozen yogurt products were different in microbiological qualities. The survival rates of pathogens spiked into the samples increased with the pH of the products. This indicates that the pH or any other factors pre-sumable supressed the growth of E. coli O157:H7 and L. monocytogenes in frozen yogurt products.

• 환경위생공학
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• 제15권1호
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• pp.109-115
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• 2000

This study was designed to investigate the quality of the simplified water supplies by regional groups in Uijoungbu. For this objective physicochemistric and microbiological experiment were performed. Simplified water in Uijoungbu(Howondong Darakwon, Singokdong Chudong, Songsandong Mangadae, Songsandong Gacbawe, Songsandong Gusungmal, Songsandong Baebul, Ganeung3dong) tested by this study physicochemistric elements suited the test. However, Songsandong Mangadae exceeded the minimum level suggested as $NO_3-N(10mg/{\ell})$. The population of general bacteria were exceeded the minimum level suggested as drinkable water(less than $100CFU/m{\ell}$). Some simplified water in Uijoungbu were proven to be contaminated.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3084-3092
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• 2010

This paper describes the development of an automated, hand-held sensor for the fast assessment of seafood freshness. The sensor developed here combined: an array-based chemical sensor, composed of incrementally different conducting polymer elements deposited on a small chip; a highly sensitive, custom-made electronics for the detection of very small signal changes; precise temperature control of the sensor chamber; and an on-board microcontroller for data collection, storage, automation, and analysis. The instrument was used to successfully test seafood samples with different degree of freshness and spoilage. A linear relationship between microbiological count and e-Nose signal for three different fish fillet was developed. Once the linear relationship is included into the hand-held unit software, the e-Nose signal can be used for assessment of seafood freshness without performing the microbiological count technique.

• 미생물학회지
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• 제7권2호
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• pp.45-56
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• 1969

The rapid deterioration of fermented rice-wine, called Tak Joo and Yak Joo, is one of the serious problems for brewing and marketing in Korea. In this study the biochemical and microbiological investigations have been performed for extension of shelf-life of the rice-wine by the method of combined heat and radiopasteurization. Major microflora in this wine is proved as Saccharomyces cereoisiar, which is destroyed by h-at treatmznt ($70^{\circ}C$, 10 min.) combined with gamma-irradiation of 240 K, rads doses. The changes of chemical constituents of them were investigated during the storage period at room temperatures of summer days($33^{\circ}C$). The results of sensory test for gamma-irradiated rice-wine with lower doses show no significant unfavourable off-odor nor color change compared with the fresh rice-wine. Therefore, it is revealed that the combined process makes possible extension of shelf-life of fermented rice-wine in markets without any deterioration and loose of its particular tastes at least for three weeks.

• 한국축산식품학회지
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• 제28권1호
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• pp.59-62
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• 2008

본 연구는 우유내 잔류물질 검사에 신속검출법으로 많이 사용되는 Delvo test가 산양유의 잔류물질 검사에도 적합한지 확인하기 위해 수행되었다. 8개 산양유목장 원유를 7회에 걸쳐 총 56개 시료를 Delvo test, Eclipse100, 그리고 Parallux로 분석하였다. 면역화학적 방법인 파라룩스에서는 양성 시료가 전혀 검출되지 않았으나 Delvo test에서는 37.5%의 양성율을 나타내었고 같은 미생물적 검출법인 Eclipse100에서는 3.6%의 양성율을 나타내었다. Delvo test는 국립수의과학검역원에서 발간한 원유검사표준화요령에 미생물학적 잔류물질 신속검출법으로 기재되어 있고, 축산물가공처리법상 "원유"의 정의가 '판매 또는 판매를 위한 처리 가공을 목적으로 하는 착유상태의 우유와 양유를 말한다'는 점을 고려할 때 Delvo test를 원유검사표준화요령에서 제외시키거나 Delvo test가 산양유의 잔류물질 신속검출법으로 적합하지 않다는 근거가 필요할 것으로 생각된다.

• Journal of Microbiology and Biotechnology
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• 제31권3호
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• pp.358-367
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• 2021

The World Health Organization (WHO) has declared the coronavirus disease 2019 (COVID-19) as an international health emergency. Current diagnostic tests are based on the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method, which is the gold standard test that involves the amplification of viral RNA. However, the RT-qPCR assay has limitations in terms of sensitivity and quantification. In this study, we tested both qPCR and droplet digital PCR (ddPCR) to detect low amounts of viral RNA. The cycle threshold (CT) of the viral RNA by RT-PCR significantly varied according to the sequences of the primer and probe sets with in vitro transcript (IVT) RNA or viral RNA as templates, whereas the copy number of the viral RNA by ddPCR was effectively quantified with IVT RNA, cultured viral RNA, and RNA from clinical samples. Furthermore, the clinical samples were assayed via both methods, and the sensitivity of the ddPCR was determined to be equal to or more than that of the RT-qPCR. However, the ddPCR assay is more suitable for determining the copy number of reference materials. These findings suggest that the qPCR assay with the ddPCR defined reference materials could be used as a highly sensitive and compatible diagnostic method for viral RNA detection.