• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.124-129
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• 2020

Sorghum (Sorghum bicolor L.) is an annual crop belonging to Poaceae, and is the fifth-largest crop after maize, wheat, rice, and barley. This study was conducted to establish an efficient seed sterilization method to manage fungal or bacterial infections of germinating sorghum seeds. Two varieties of sorghum seeds (BTx623 and SAP317) were treated with benomyl-thiram and thiophanate-methyl triflumizole which are known to be effective disinfectants for sorghum seeds. For SAP317, the highest germination rate was accomplished with 24-hour treatment of both chemicals at a 200× dilution rate. For BTx623, the highest germination rate was observed after 24-hour treatment at a 200×/400× dilution rate for benomyl-thiram and control/200× for thiophanate-methyl triflumizole. Consequently, the optimal treatment for the seed disinfection in sorghum seeds may be at the dilution rate of 200× or 400× for 24 hours.

• Microbiology and Biotechnology Letters
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• v.31 no.2
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• pp.177-181
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• 2003

Eleven bacterial strains which are able to utilize terephthalic acid as a carbon and an energy source for growth were isolated from the soil of 7 water quality evaluation points in Kyonggi area of Korea. Phthalic acid isomer degrading activity of the isolates from the 4 contaminated points was higher than those from the 3 clean points. Among 11 isolates, 4 isolates which have high terephthalic acid degrading activity and degrade two phthalic acid isomers were identified by partal 16S rDNA sequence determination. One of them was identified as Pseudomonas putida, and the others as Comamonas testosteroni. Thus a large number of phthalic acid isomer degrading bacteria in domestic soil were inferred as C. testosteroni. On the basis of these results, the PCR detection of C. testosteroni in soil was applied to monitor soil contamination by phthalic acid isomers. The DNA of C. test-osteroni extracted from 4 g soil was directly detected by PCR with C. testosteroni specific primer pair. The amount of PCR products was different according to sampling sites and more PCR products were obtained from contaminated sites than those from clean sites (Gulpo-chun＞Anyang-chun＞Hwangguji-chun>Shin-chun＞Huk-chun＞Pukhan-river>Kapyeong-chun). This result was coincided with that of the viable cell counts for terephthalic acid degrading bacteria.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.261-266
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• 1979

This experiment was carried out to evaluate the sanitary quality of cultured vegetables and to check the removing rate of bacteria by treating methods such as washing with tap water or commercial detergent, or blanching. Samples collected from farm land located at Busan suburbs and markets were Fragaria chiloensis var. ananasa, Lycopersicum esculentum, Capsium longum, Cucumis sativus, Lactuca scariola var. sativa leaf of Perilla frutescens var, japonica, Oananthe stolonifera and Allium odoium. Fecal coliform MPN was ra god from less than 30 to 430,000 per 100 grams of samples examined while plate count was $7.2\times10^3\;to\;2.2\times10^7$ per gram. Usually contamination rate of fecal coliform of leaf vegetal)les was much higher than that of fruit vegetables. Removing rate of bacterial density of vegetables by washing three times with tap water was about $70\%$ in fruit vegetables, about $20\%$ in leaf vegetables but it was about $80\%$ in leaf vegetables by washing with a commercial detergent. Sirvival rate of viable cell count of leaf vegetables was less than $0.1\%$ after blanching for one minutes in boiling tap water, Composition of coliform was $18\%$ Escherichia coli group, $22\%$ Citrobacter freundii group and $60\%$ Klebsiella aerogenes group, among Escherichia coli, type I being $16\%$ in total. The coliform detection from BGLB gas positive tubes being planted with various vegetables was about $80\%$ in the result of IMViC reaction.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.747-757
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• 2014

Since the air contamination by air pollutants from indoor construction materials and daily supplies has been increased in recent decades, the public interest of using environmentally friendly products and improving indoor air quality also attracted much attention. As known as effects of phytoncide, it has been used in construction materials and daily supplies with various method. In this study, hinoki cypress (Chamaecyparis obtusa) was used because of its high contents of phytoncide. The leaves of hinoki cypress (C. obtusa), which generated by pruning, were extracted by steam distillation, and then used as humidification water source. Volatile organic compound (VOC) from C. obtusa were characterized by GC-MS (Gas chromatograph-Mass spectrophotometry) in order to evaluate effects and risks of using C. obtusa extracts. Total 86 types and 116 types of VOC were detected from distilled water (DI water) and C. obtusa extracts, respectively. Aromatic compounds (DI water: 13 types, 53%; C. obtusa extracts: 13 types, 38%) and terpenoids (DI water: 16 types, 23%; C. obtusa extracts: 23 types, 33%) were detected more diverse types and higher amount than other compound categories. No additional aromatic compounds were found from C. obtusa extracts, so C. obtusa extracts did not affect on aromatic compounds emission. However, in terpenoids, total amount of emission from C. obtusa extracts increased to 33% from 23% (DI water) and 7 more types of compounds were found from C. obtusa extracts. Especially, from C. obtusa extracts, terpinen-4-ol was emitted 71 times higher than DI water. During the humidification with C. obtusa extracts, emitted terpenoid compounds were well known for higher anti-bacterial, anti-insect, and anti-septic functions, but also these had anti-hypertensive and anti-cancer activities. Therefore, terpenoids from C. obtusa extracts can help to improve public health by using humidifier.

• Journal of Life Science
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• v.18 no.12
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• pp.1771-1774
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• 2008

Control microbial contamination in pathogens to soy sprouts has always been highly concerned in soybean sprout industries because the soybean sprouts are consumed largely as a nutritious fresh vegetable around the world. However, pathogens in soy sprouts are little known. Here, we isolated a strain of Pseudomonas sp. SN239 that caused severer symptoms in sprouts of many soybean cultivars. In phylogenetic relationships using 16S ribosomal RNA sequences of the Pseudomonas species, the identified Pseudomonas sp. SN239 was grouped with P. putita, P. plecoglossicida, P. monteilii and P. mevalonii. Thus, the bacterial strain SN239 might be a newly identified Pseudomonas species which closely related to P. putida. Furthermore, we found that a Korean indigenous soybean (Glycine max) cultivar YNPCSS3-19 has strong resistance against the Pseudomonas sp. SN239.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.495-502
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• 2020

Processing fresh produce into fresh-cut products increases the risk of bacterial growth and contamination by breaking the exterior barrier of produce. Our objective in this study was to develop predictive models of Listeria monocytogenes in the fresh-cut salad, fresh-cut pineapple, and frozen mango. Predictive growth and survival models were developed to predict the change of L. monocytogenes populations in the fresh-cut salad (4, 10, 12, 13, 17, 25, and 36℃), fresh-cut pineapple (4, 10, 17, 25, 30, and 36℃), and frozen mango (-2, -10 and -18℃) as a function of temperature. The growth of L. monocytogenes in fresh-cut salad and pineapple was observed at above 13℃ and 10℃, respectively. The growth of L. monocytogenes in pineapple was faster than in salad. The delta value of L. monocytogenes in frozen mango increased as the storage temperature decreased. The results indicate that L. monocytogenes behave differently according to the physicochemical properties of fresh-cut fruits and vegetables. Since L. monocytogenes grow and survive well in refrigerated and frozen conditions, management programs and preventive controls for the processing of fresh-cut produce should be effectively implemented to enhance the safety of fresh-cut fruits and vegetables at retail markets.

• Food Science and Preservation
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• v.15 no.4
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• pp.606-611
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• 2008

Myungran Jeotkal, Korean fermented seafood, and its ingredients(hot red pepper powder, ginger, garlic, and seasoning mix) were irradiated with 0, 0.5, 1.0, 2.0, and 5.0 kGy of gamma rays and stored at 4C for 4 weeks to determine changes in microbiological and sensory characteristics. Water activities of Myungran Jeotkal, hot red pepper powder, ginger, garlic, and seasoning mix were 0.89 0.56, 0.98, 0.99, and 0.07, respectively. Myungran Jeotkal was observed to be initially contaminated. Total aerobic bacteria, yeast and mold, and coliform levels were 6.7, 4.3, and 3.6 log CFU/g, respectively. Irradiation at 2 kGy afforded approximately a 4 log reduction in total aerobic bacteria, and a 3 log drop in both yeast and mold levels and coliform bacteria(P<0.05). No viable microbial cells were detected in Myungran Jeotkal after 5 kGy of irradiation(at a detection limit of 101 CFU/g). The total aerobic bacterial level in red pepper powder was 6.3 log CFU/g and this component, of the tested ingredients, contributed most to the microbial contamination of Myungran Jeotkal. The initial count of total aerobic bacteria, 6.3 log CFU/g, was significantly reduced to 4.5 log CFU/g after irradiation(P<0.05). Sensory evaluation showed that gamma irradiation of up to 5.0 kGy did not adversely affect overall acceptability of Myungran Jeotkal or its ingredients during cold storage. Therefore, gamma irradiationwas effective to extend the shelf-life of Myungran Jeotkal.

• 한국균학회소식:학술대회논문집
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• 2018.05a
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• pp.44-44
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• 2018

Fusarium head blight (FHB) caused by infection with Fusarium graminearum leads to enormous losses to crop growers, and may contaminate grains with a number of Fusarium mycotoxins that pose serious risks to human and animal health. Antagonistic bacteria that are used to prevent FHB offer attractive alternatives or supplements to synthetic fungicides for controlling FHB without the negative effects of chemical management. Out of 500 bacterial strains isolated from soil, Bacillus amyloliquefaciens JCK-12 showed strong antifungal activity and was considered a potential source for control strategies to reduce FHB. B. amyloliquefaciens JCK-12 produces several cyclic lipopeptides (CLPs) including iturin A, fengycin, and surfactin. Iturin A inhibits spore germination of F. graminearum. Fengycin or surfactin alone did not display any inhibitory activity against spore germination at concentrations less than 30 ug/ml, but a mixture of iturin A, fengycin, and surfactin showed a remarkable synergistic inhibitory effect on F. graminearum spore germination. The fermentation broth and formulation of B. amyloliquefaciens JCK-12 strain reduced the disease incidence of FHB in wheat. Furthermore, co-application of B. amyloliquefaciens JCK-12 and chemical fungicides resulted in synergistic in vitro antifungal effects and significant disease control efficacy against FHB under greenhouse and field conditions, suggesting that B. amyloliquefaciens JCK-12 has a strong chemosensitizing effect. The synergistic antifungal effect of B. amyloliquefaciens JCK-12 and chemical fungicides in combination may result from the cell wall damage and altered cell membrane permeability in the phytopathogenic fungi caused by the CLP mixtures and subsequent increased sensitivity of F. graminearum to fungicides. In addition, B. amyloliquefaciens JCK-12 showed the potential to reduce trichothecenes mycotoxin production. The results of this study indicate that B. amyloliquefaciens JCK-12 could be used as an available biocontrol agent or as a chemosensitizer to chemical fungicides for controlling FHB disease and as a strategy for preventing the contamination of harvested crops with mycotoxins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.188-192
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• 1984

In order to investigate the hygienic status of commercial red pepper powder, one sample was directly prepared from raw red pepper which was purchased at market and the other one was a commercial red pepper powder. They were used for the investigation upon the status of microbial contamination, effect of irradiation for sterilization and physicochemical changes during 3 months of storage. Total bacterial counts of commercial red pepper powders were 3.83 to $6.68{\times}10^6$ per gram and coliform group was shown to be positive in some products. Total bacteria and coliform group were sterilized by the irradiation of 9 kGy and 3 kGy, respectively and no microorganisms were grown up until 3 months of storage at room temperature. The $D_{10}$ values of total viable bacteria in red pepper powders were 1.52 to 1.58 kGy. Chemical components such as moisture, total and reducing sugars were slightly decreased during the storage period. The contents of capsanthin and capsaicin were partly affected by the high dose irradiation but the difference between unirradiated and irradiated groups was diminished with the elapse of storage period.

• Food Science and Preservation
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• v.21 no.4
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• pp.593-599
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• 2014

This study was conducted to determine the antioxidant potentials of some available plants to source alternate antioxidants and antibiotics. The antioxidant activity was evaluated by determining the antioxidant activity reducing powers and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities of extracts from some local edible native plants. The DPPH radical scavenging activity of the extracts was found to have been 0.41-94.84%. The Elsholtziasplendens NAKAI extract ($85^{\circ}C$, ethanol, accelerated solvent extraction) showed the highest level of antioxidant activity. Eight samples of plant extracts were evaluated for their antimicrobial activities against three microflora (Bacillus subtilis, Escherichia coli, and Candida albicans) using disc diffusion assay. Two samples (Geranium krameri FR. Et SAV. and Cleyera japonica Thunb.) had much more intensive antimicrobial activities than the control. However, their DPPH free radical scavenging activity levels were only 14.50 and 13.85, respectively. It is suggested that they could be used as natural preservatives against bacterial contamination in cosmetics and foods, in place of the common synthetic preservatives currently used.