• 한국초지조사료학회지
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• 제43권3호
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• pp.148-155
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• 2023

This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.010⁴ cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 10⁵ cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.

• 대한방사선기술학회지:방사선기술과학
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• 제41권5호
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• pp.427-435
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• 2018

There was a shortage of research reports on sterilization criterion and contamination of ultrasonic probes. Therefore, in this study, we were going to provide a basic study to measure the level of microbial contamination in ultrasonic probes and to investigate the radiographer's awareness of infection. After the scan, samples were collected from the rubber part of the probe by opening a sterile swab (Transport Medium AM608-1S) for medical bacteria collection with the remaining gel removed with a paper towel. Also, the collected samples of bacteria were grown for seven days and then the laboratory was analyzed. Among the total 29 types of microorganisms, Micrococcus luteus 21(26%), Moraxella species 16(20%), Coagulase negative staphylococcus 8(10%), Bacillus species 5(7%), Bicillus circulans 3(5%), Acinetobacter lwoffii 2(2%), and 1 other Candida parapsilosis (1%) a number of bacteria and fungus, was detected. In a disinfectant experiment using LuciPac Pen on the Lumitester PD-30s, we cultured the rubber part of the probe two to three times to measure the bacteria. Bacteria decreased to 97% with Aquanax (alkaline reduced water 100%), 99% with Klarion wash (0.01% sodium hydroxide), 94% with Klarion disinfection (0.01% nitrous acid water), Sterilization was best with Klarion wash (0.01% sodium hydroxide). Therefore, guidelines for cleaning and disinfection of ultrasonic probes was required, and further development of probe-only disinfectants is required.

• 한국산학기술학회논문지
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• 제11권12호
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• pp.4826-4832
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• 2010

본 연구는 2010년 6월 1일부터 2010년 7월 30일까지 2개월간 서울에 위치한 3곳의 약업사에서 각각 13종의 한약재를 구입하여 이들에 대한 총 호기성 세균 및 진균에 대한 미생물 오염 실태를 분석하여 한약재에 대한 미생물 오염 검사기준을 위한 기초자료로 활용하고자 수행되었다. WHO의 총 호기성 세균 및 진균수 오염한도인 $10^7$ CFU/g과 $10^4$ CFU/g과 비교하면, 총 호기성 균 오염(7.7%)보다는 진균의 오염(12.8%)이 더 높은 것으로 나타났다. 117개의 세균 집락을 대상으로 한 16S rRNA 유전자에 대한 DNA 상동성 분석은 내성 포자를 형성하는 B. cereus를 포함한 토양 유래 세균들이 약 96.6%를 차지하여 한약재의 채취와 보관 및 유통 과정에서의 미생물 오염 한도 기준 마련이 시급한 것으로 나타났다. 결론적으로 본 연구는 한약의 가공과정에 세균 및 진균의 혼입 가능성에 대한 시험조사와 함께 지속적인 한약재에 대한 미생물 오염실태 조사가 필요하다는 것을 시사하고 있다.

• The Plant Pathology Journal
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• 제35권5호
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• pp.437-444
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• 2019

Chlorine dioxide ($ClO_2$) has been widely used as an effective disinfectant to control fungal contamination during postharvest crop storage. In this study, Fusarium oxysporum f. sp. batatas SP-f6 from the black rot symptom of sweetpotato was isolated and identified using phylogenetic analysis of elongation factor 1-${\alpha}$ gene; we further examined the in vitro and in vivo inhibitory activities of $ClO_2$ gas against the fungus. In the in vitro medium tests, fungal population was significantly inhibited upon increasing the concentration and exposure time. In in vivo tests, spore suspensions were drop-inoculated onto sweetpotato slices, followed by treatment using various $ClO_2$ concentrations and treatment times to assess fungus-induced disease development in the slices. Lesion diameters decreased at the tested $ClO_2$ concentrations over time. When sweetpotato roots were dip-inoculated in spore suspensions prior to treatment with 20 and 40 ppm of $ClO_2$ for 0-60 min, fungal populations significantly decreased at the tested concentrations for 30-60 min. Taken together, these results showed that $ClO_2$ gas can effectively inhibit fungal growth and disease development caused by F. oxysporum f. sp. batatas on sweetpotato. Therefore, $ClO_2$ gas may be used as a sanitizer to control this fungus during postharvest storage of sweetpotato.

• 한국환경보건학회지
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• 제8권1호
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• pp.25-30
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• 1982

The incidence of hospital infection has been seriously increased in the general hospital in recent years. This study was performed on hospital air and materials in a General Hospital in Seoul from June to December in 1980. The results were as follows: 1. Air sampling was done in multiple strategic areas by exposing standard petridishes for 5 minutes. There was a significant difference of airborne microbe between places. ($F._{99}$ = 3.2, p < 0.01). 2. The mean colony count was 8.6$\pm$6.2 colonies / plate / 5 minutes. 3. Gram stains of colony in air sampling were Gram (+) cocci 66.5%. Gram (+) rod 18.4%, Gram (-) cocci 1.3%, Gram (-) rod 8.7% Fungus 4.5%. 4. For the evaluation of sterilization of steam sterilizer and ethylene oxide gas sterilizer, biological monitoring were done by commercial spore strip. Positive culture was obtained in 2 out of 41 tests on 3 steam sterilizers, and in 3 out of 13 tests on ethylene oxide gas sterilizer. 5. Product sampling and culture were done for 2 kinds of disinfectants and 30 sets of various operation package or dressing materials. Positive culture was obtained in one disinfectants.

• 한국동물위생학회지
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• 제30권2호
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• pp.283-286
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• 2007

Fungus generally doesn't produce toxic or harmful substances so it has low chances to cause food poisoning. However it leads to change appearance, odor and characteristics of the contaminated foods and result in sanitary risk problems. Therefore the contamination of fungi should be prevented since they are not proper for human consumption. Green fungi with white outline raised from the air cell of cooked eggs which were collected by Gyeongi Livestock Veterinary Service in August, 2006. The results came out after the cultivation using Sabouraud's Dextrose Agar(SDA). The conidium appeared white and monospore, the shape of colony was round and oval. Conidiophore was brown and granulated and wrinkles and formed. It was confirmed as Aspergillus nidulans based on the dying using Lactophenol cotton blue, the observation of septum and vesicle from the grown spores, and rDNA sequencing.

• Toxicological Research
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• 제32권1호
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• pp.81-87
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• 2016

Aflatoxin B1 (AFB1) is produced by Aspergillus flavus growing in feedstuffs. Early detection of maize contamination by aflatoxigenic fungi is advantageous since aflatoxins exert adverse health effects. In this study, we report the development of an optimized conventional PCR for AFB1 detection and a rapid, sensitive and simple screening Real-time PCR (qPCR) with SYBR Green and two pairs of primers targeting the aflR genes which involved aflatoxin biosynthesis. AFB1 contaminated maize samples were divided into three groups by the toxin concentration. Genomic DNA was extracted from those samples. The target genes for A. flavus were tested by conventional PCR and the PCR products were analyzed by electrophoresis. A conventional PCR was carried out as nested PCR to verify the gene amplicon sizes. PCR-RFLP patterns, obtained with Hinc II and Pvu II enzyme analysis showed the differences to distinguish aflatoxin-producing fungi. However, they are not quantitative and need a separation of the products on gel and their visualization under UV light. On the other hand, qPCR facilitates the monitoring of the reaction as it progresses. It does not require post-PCR handling, which reduces the risk of cross-contamination and handling errors. It results in a much faster throughout. We found that the optimal primer annealing temperature was $65^{\circ}C$. The optimized template and primer concentration were $1.5{\mu}L\;(50ng/{\mu}L)$ and $3{\mu}L\;(10{\mu}M/{\mu}L)$ respectively. SYBR Green qPCR of four genes demonstrated amplification curves and melting peaks for tub1, afIM, afIR, and afID genes are at $88.0^{\circ}C$, $87.5^{\circ}C$, $83.5^{\circ}C$, and $89.5^{\circ}C$ respectively. Consequently, it was found that the four primers had elevated annealing temperatures, nevertheless it is desirable since it enhances the DNA binding specificity of the dye. New qPCR protocol could be employed for the determination of aflatoxin content in feedstuff samples.

• 설비공학논문집
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• 제18권8호
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• pp.620-626
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• 2006

Recently, indoor air quality (IAQ) is one of the greatest problems in our modern societies. Although research for IAQ is made rapid progress but IAQ problems concerning in door microorganism contamination is required to be studied still more. So we have investigated the indoor microorganism concentration of a variety of department store, subway station, underground shopping center, kindergartens, library where people complain about the in-door air quality. The experiment on microorganism concentration of indoor air was carried out and the average of total microorganisms was measured. Comparing the experimental results with existing foreign criterion, the experimental results show that the ministry of environment recommendation microorganism concentration value ($800 CFU/m^3$) is in need of revision in the near future.

• 식물병연구
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• 제20권4호
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• pp.259-263
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• 2014

차아염소산나트륨의 벼 키다리병 종자소독제로서 활용 가능성을 구명하고자, 항균 활성 효과와 종자소독 효과를 연구한 결과, 차아염소산나트륨이 높은 항균 활성을 나타내어 $100{\mu}l/l$ 이상의 농도에서 균총이 형성되지 않았으며 $80{\mu}l/l$ 농도에서도 균 총형성이 현저히 낮았다. 벼 키다리병균 감염 벼 종자를 차아염소산나트륨 0.3% 농도로 8시간 침지 처리 시 종자소독효과가 90%로 높았다. 또한 차아염소산나트륨 0.5%, 0.3% 용액에 감염종자를 각각 12시간 처리하였을 벼 키다리병 발병율이 4.3%, 4.7%로 무처리 발병율 97.3%에 비해 현저히 억제되었으며, 유묘 출현율이 무처리 대비 29.1%, 26.9% 높았다. 그리고 벼 키다리병이 발생하여 자연 감염된 주남벼 종자를 사용하여 차아염소산나트륨 처리한 후 prochloraz 처리와, prochloraz를 처리한 후 차아염소산나트륨 처리의 종자 감염율이 각각 4.0%, 6.3% 로서 prochloraz 단독처리 13.7% 보다 낮은 경향을 보였으며, 벼 키다리병 발병율도 각각 3.7%, 8.3% 로 prochloraz 단독처리 14.3% 보다 낮았다. 아울러 차아염소산나트륨을 처리한 후 prochloraz를 처리한 것에서 더 높은 종자소독효과를 보였다.

• 한국환경보건학회지
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• 제11권2호
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• pp.41-54
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• 1985

This study was conducted for the improvement of milk quality and milk hygiene in public health point of view. Investigation of mastiris infection rate, isolation and identification of causative microorganisms in CMT positive milk, investigation of milk contamination level by measuring the bacteria and soma tic cell counts and investigation of dairy management in farms were performed on 1.605 quarters milk of 434 cows of 20 dairy farms in Gyunggi-area from September 1983 to March 1984. The results were summarized as follows 1. Sixteen (3.7%) of 434 cows were found to be infected with clinical mastiris. 234 (53.9%) of 434 cows and 608(37.9%) of 1, 605 quarters were found to be infected with subclinical mastiris. 2. The causative microorganisms isolated were Staphylococcus aureus (38.3%), Staphylococcus epidermidis(21.0%), Micrococci(13.6%), Streptococcus spp. (12.3%), E. coli (7.4%), Fungus & Yeast (1.6%) and others (5.8%). 3. Total numbers of bacteria were $9.2{\times}10^6$ to $1.21{\times}10^7/ml$(av. $1.805{\times} 10^7/ml$), numbers of coliform bacteria were $4.1{\times} 10^5$ to $9.4{\times} 10^5$/ml(av. $7.05{\times} 10^5$/ml) and somatic cell counts were $4.8{\times} 10^5$ to $1.52{\times} 10^6$ cells/ml (av. $9.5{\times} 10^5$cells/ml) in bulk milk. 4. As comparing with CMT score of +, ++ and +++, somatic cell counts were $3.4{\times} 10^5$ to $1.64{\times} 10^6$ cells/ml (av. $6.41{\times} 10^5$cells/ml), $5.4{\times} 10^5$ to $2.75{\times} 10^6$ cells/ml(av. $1.762{\times} 10^6$cells/ml) and $1.97{\times} 10^6$ to $9.75{\times} 10^6$ cells/ml(av. $7.781{\times} 10^6$cells/ml), respectively. 5. In investigation on dairy management, performance of dry cow therapy, teat dipping after milking, disinfection of milking machine at every milking, replacement of milk liner within 6months and opportunity of acquirement for the mastiris control techniques by dairy education were 65%, 40%, 45%, 55% and 50% in 20 dairy farms, respectively.