• 한국축산식품학회지
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• 제32권4호
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• pp.448-457
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• 2012

The predictive ability for off-flavor development and quality change of ground beef was evaluated using a microbial time temperature indicator (TTI). Quality indices such as off-flavor detection (OFD) time, color, pH, volatile basic nitrogen (VBN), aerobic mesophilic bacteria (AMB) counts, and lactic acid bacteria (LAB) counts were measured during storage at 5, 10, 15, and $25^{\circ}C$, respectively. Arrhenius activation energies (Ea) were estimated for temperature dependence. The Ea values for TTI response (changes in titratable acidity (TA)), VBN, AMB counts, LAB counts, and freshness, which is defined based on OFD time for quality indices of ground beef, were 106.22 kJ/mol, 58.98 kJ/mol, 110.35 kJ/mol, 116.65 kJ/mol, and 92.73 kJ/mol, respectively. The Ea of microbial TTI was found to be closer to those of the AMB counts, LAB counts, and freshness. Therefore, AMB counts, LAB counts, and freshness could be predicted accurately by the microbial TTI response due to their Ea similarity. The microbial TTI exhibited consistent relationships between its TA change and corresponding quality indices, such as AMB counts, LAB counts, and freshness, regardless of storage temperature. Conclusively, the results established that the developed microbial TTI can be used in intelligent packaging technology for representing some selected quality indices of ground beef.

• 한국환경농학회지
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• 제39권4호
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• pp.343-351
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• 2020

BACKGROUND: Irrigation water is known to be one of the major sources of bacterial contamination in agricultural products. In addition, anti-microbial resistance (AMR) bacteria in food products possess serious threat to humans. This study was aimed at investigating the prevalence of foodborne bacteria in irrigation water and evaluating their anti-microbial susceptibility. METHODS AND RESULTS: Surface water (n = 66 sites) and groundwater (n = 40 sites) samples were collected from the Gyeongi and Gangwon provinces of South Korea during April, July, and October 2019. To evaluate the safety of water, fecal indicators (Escherichia coli) and foodborne pathogens (E. coli O157:H7, Salmonella spp., and Listeria monocytogenes) were examined. E. coli isolates from water were further tested for antimicrobial susceptibility using VITEK2 system. Overall, detection rate of foodborne pathogens in July was highest among three months. The prevalence of pathogenic E. coli (24%), Salmonella (3%), and L. monocytogenes (3%) was higher in surface water, while only one ground water site was contained with pathogenic E. coli (2.5%). Of the 343 E. coli isolates, 22.7% isolates were resistant to one or more antimicrobials (ampicillin (18.7%), trimethoprim-sulfamethoxazole (7.0%), and ciprofloxacin (6.7%)). CONCLUSION: To enhance the safety of agricultural products, it is necessary to frequently monitor the microbial quality of water.

• The Plant Pathology Journal
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• 제31권3호
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• pp.212-218
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• 2015

In this study, we developed a species-specific PCR assay for rapid and accurate detection of three Xanthomonas species, X. axonopodis pv. poinsettiicola (XAP), X. hyacinthi (XH) and X. campestris pv. zantedeschiae (XCZ), based on their draft genome sequences. XAP, XH and XCZ genomes consist of single chromosomes that contain 5,221, 4,395 and 7,986 protein coding genes, respectively. Species-specific primers were designed from variable regions of the draft genome sequence data and assessed by a PCR-based detection method. These primers were also tested for specificity against 17 allied Xanthomonas species as well as against the host DNA and the microbial community of the host surface. Three primer sets were found to be very specific and no amplification product was obtained with the host DNA and the microbial community of the host surface. In addition, a detection limit of $1pg/{\mu}l$ per PCR reaction was detected when these primer sets were used to amplify corresponding bacterial DNAs. Therefore, these primer sets and the developed species-specific PCR assay represent a valuable, sensitive, and rapid diagnostic tool that can be used to detect three specific pathogens at early stages of infection and may help control diseases.

• Journal of Microbiology and Biotechnology
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• 제25권11호
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• pp.1773-1781
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• 2015

Environmental security is one of the major concerns for the safety of living organisms from a number of harmful pollutants in the atmosphere. Different initiatives, legislative actions, as well as scientific and social concerns have been discussed and adopted to control and regulate the threats of environmental pollution, but it still remains a worldwide challenge. Therefore, there is a need for developing certain sensitive, rapid, and selective techniques that can detect and screen the pollutants for effective bioremediation processes. In this perspective, isolated enzymes or biological systems producing enzymes, as whole cells or in immobilized state, can be used as a source for detection, quantification, and degradation or transformation of pollutants to non-polluting compounds to restore the ecological balance. Biosensors are ideal for the detection and measurement of environmental pollution in a reliable, specific, and sensitive way. In this review, the current status of different types of microbial biosensors and mechanisms of detection of various environmental toxicants are discussed.

• KSBB Journal
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• 제18권2호
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• pp.79-89
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• 2003

This article contains an overview of acoustic wave devices, the theory and application of piezoelectric quartz crystal microbalances(PZ QCM), clinical analysis, gas phase detection, DNA biosensors, drug analysis, food microbial analysis and environmental analysis.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1170-1177
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• 2005

Terminal-restriction fragment length polymorphism (T-RFLP) analysis was used to monitor inoculated oil-degrading microorganisms during bioremedial treatability tests. A pair of universal primers, fluorescently labeled 521F and 1392R, was employed to amplify small subunit rDNA in order to simultaneously detect two bacterial strains, Corynebacterium sp. IC10 and Sphingomonas sp. KH3-2, and a yeast strain, Yarrowia lipolytica 180. Digestion of the 5'-end fluorescence/labeled PCR products with HhaI produced specific terminal-restriction fragments (T-RFs) of 185 and 442 bases, corresponding to Corynebacterium sp. IC10 and Y. lipolytica 180, respectively. The enzyme NruI produced a specific T-RF of 338 bases for Sphingomonas sp. KH3-2. The detection limit for oildegrading microorganisms that were inoculated into natural environments was determined to be $0.01\%$ of the total microbial count, regardless of the background environment. When three oil-degrading microorganisms were released into oil-contaminated sand microenvironments, strains IC10 and 180 survived for 35 days after inoculation, whereas strain KH3-2 was detected at 8 days, but not at 35 days. This result implies that T-RFLP could be a useful tool for monitoring the survival and relative abundance of specific microbial strains inoculated into contaminated environments.

• 미생물학회지
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• 제28권3호
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• pp.229-235
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• 1990

평판배지상 세균 colony의 체외 세포 효소활성을 직접 측정할 수 있는 신속하고 정확한 방법에 대하여 기술하였다. 일반적으로 세균의 효소 특성을 살피기 위해서는 단백질, 전분, chitin, tween-80 등과 같은 고분자 물질을 첨가한 선택배지를 사용하고 있으나 그 방법상 여러 가지 문제점이 있다 그러므로 본 연구에서는 형광물질의 일종인 Methvlumbell liferyl(MUF) 기질이 일반적으보 사용되고 있는 천연 고분자 물질고 유사한가를 순수분리세균 균주를 이용하여 실험으로 검증하였다. MUF 기질 분해원리에 기초를 둔 기술한 새로운 방법은 순수 분리 균주는 물론 colony 계수에 사용되는 평판배지상에서도 세균의 체외세포 효소 특성을 정량적으로 측정 가능하게 한다. 본 새로운 방법을 이용하여 담수 생태계와 해양 퇴적토내 종속영양세균의 체외 효소 활성을 측정하여 고찰하였다.

• 한국식품위생안전성학회지
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• 제36권5호
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• pp.407-417
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• 2021

새싹삼의 곰팡이 발생을 조사하기 위해 18점의 유통중인 새싹삼을 수집하여 곰팡이 발생빈도를 분석하였다. 전체 시료의 총 곰팡이 발생빈도는 평균 113.3-174.1%였고 Penicillium spp.의 발생빈도가 가장 높았다. 곰팡이 발생빈도는 이끼가 잎, 줄기, 뿌리보다 유의하게 높았다. 잎과 줄기에서는 Penicillium spp.이, 뿌리에서는 Fusarium spp.의 발생이 높았으며 각각의 우점종은 P. olsonii와 F. oxysporum으로 동정되었다. 계통발생학적 분석을 통해 Fusarium spp.은 총 9개 종, Aspergillus spp.은 A. westerdijkiae와 A. favus, Penicillium spp.은 총 11개 종이 동정되었다. 곰팡이독소 생성 종으로 알려진 25균주의 독소형을 PCR로 검정한 결과 19점의 균주에서 각 독소형이 확인되었다. 이 중 A. flavus 2점과 A. westerdijkiae 11점이 aflatoxin과 ochratoxin A을 각각 생성하였고 일부 균주는 높은 독소생성능을 보였다. 이 결과는 새싹삼 생산에 있어 곰팡이 발생에 대한 지속적인 모니터링 및 관리방안이 필요함을 시사하였다.

• 대한토목학회논문집
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• 제36권5호
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• pp.839-846
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• 2016

유류오염은 우리나라의 대표적인 토양 비점오염원으로 알려져 있으며, 이를 정화하는 토양의 능력은 토양 자원의 기능적 가치 평가에서 매우 유의하다. 특히 절/성토 설계 등의 친환경 건설기술 측면에서 토양의 유류오염정화능력을 평가하는 것은 중요하다. 그러나 마이크로코즘 실험을 포함한 기존의 토양 유류 오염정화능력 평가기법은 경제적, 시간적인 제약이 많아 광범위한 지역에 적용하기 어렵다. 이에 본 연구에서는 유류 오염물질 중 가솔린의 대표적 오염물질인 톨루엔을 선정하여 쉽고 간편하게 측정할 수 있는 토양의 미생물 다양성 지표를 이용, 토양의 유류오염 정화능력을 평가하는 기법을 제시하였다. 연구를 통해 미생물 군집의 다양성 지표 중 Shannon index가 토양의 정화능력 인자인 Specific Degradation Rate ($V_{max}$)와 상관성 관계가 있음을 보였고, 두 인자 간의 상관식을 도출할 수 있었다. 또한 본 상관식을 Michaelis-Menten kinetics에 적용하여 미생물 다양성 인자만으로 토양의 톨루엔 정화능력을 평가할 수 있는 기법을 제시하였다. 본 기법을 통해 간단히 토양의 톨루엔 정화능력을 평가할 수 있으며, 친환경 건설기술분야와 같은 다양한 공학적 분야에 광범위하게 활용될 수 있을 것으로 기대된다.

• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.560-570
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• 2007

The effective and accurate assessment of the total microbial community diversity is one of the primary challenges in modem microbial ecology, especially for the detection and characterization of unculturable populations and populations with a low abundance. Accordingly, this study was undertaken to investigate the diversity of the microbial community during the biodegradation of cis- and trans-dichloroethenes in soil and wastewater enrichment cultures. Community profiling using PCR targeting the l6S rRNA gene and denaturing gradient gel electrophoresis (PCR-DGGE) revealed an alteration in the bacterial community profiles with time. Exposure to cis- and trans-dichloroethenes led to the disappearance of certain genospecies that were initially observed in the untreated samples. A cluster analysis of the bacterial DGGE community profiles at various sampling times during the degradation process indicated that the community profile became stable after day 10 of the enrichment. DNA sequencing and phylogenetic analysis of selected DGGE bands revealed that the genera Acinetobacter, Pseudomonas, Bacillus, Comamonas, and Arthrobacter, plus several other important uncultured bacterial phylotypes, dominated the enrichment cultures. Thus, the identified dominant phylotypes may play an important role in the degradation of cis- and trans-dichloroethenes.