• The Korean Journal of Mycology
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• v.14 no.2
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• pp.109-119
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• 1986

The correlations between environmental influences on microorganisms in soil and its effects on disease development in ginseng field were studied to obtain some useful data for increasing ginseng production and effective preventive measures against the root rot caused by soil-borne pathogens. The diseased replanted ginseng fields were selected as the diseased field and the healthy plot in first planted field selected as control in three major Korean ginseng producing areas such as Kumsan, Goesan and Poonggi. The physicochemical characteristics of the soil were analyzed and microorganisms susceptible for root rot of ginseng, such as Fusarium spp. and general fungi were investigated for their population density in various soil conditions. Correlations between soil microbial populations and environmental factors were investigated. The numbers of Fusarium spp. propagules were abundant in fall in both soil conditions. The numbers of Fusarium spp. were 1.9 to 2.6 times higher in replanted field than first planted field except Goesan area. Relative ratio of Fusarium spp. to total fungi propagules in replanted field was 1.6 times higher in replanted field than first planted field indicating higher numbers of Fusarium spp. distributed in replanted field of soil. The numbers of propagules of total fungi were increased in June and July and there was no sensitive variation according to the temperature. There was no significant difference in vertical distributions of total fungi according to soil depth, while the total fungi were abundant in the surface layer and $10{\sim}15\;cm$ layer. The contents of organic matter and phosphate in healthy field were somewhat high, and phosphate/organic matter ratio and Mg contents were high in diseased field. All of the soils showed a weak acidic pH of 4.5 to 5.7. Soil moisture contents were increased during winter season, but did not show any significant changes during the growing periods, showing 24.6% in healthy field and 19.5% in diseased field respectively. Soil temperature was the highest in July and August and the lowest in January and February.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.341-348
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• 2016

This study aimed to develop a microbial process for producing aminolevulinic acid (ALA) using crude glycerol. In the culture of ALA-producing cells (Escherichia coli/pH-hemA) in a medium containing crude glycerol, the cell density and production were 1.8-fold and 1.2-fold lower than those obtained from pure glycerol, respectively. However, the cell growth and production were improved by supplementing the medium with trehalose (30 or 100 g/l). Engineered cells (E. coli/pH-hemA/pS-otsBA) were constructed to express otsBA and their culture performance was compared with that of control cells (E. coli/pH-hemA/ pSTV28). The effects of isopropyl β-D-1-thiogalactopyranoside (IPTG) concentration and the time of induction were examined to improve the cell growth and ALA production in engineered cells cultured using crude glycerol. When 0.6 mM of IPTG was added at the beginning of the exponential growth phase, the ALA produced by cells was 2,121 mg/l, which was comparable to that from pure glycerol. The results demonstrate that otsBA expression endowed cells with the capacity to tolerate the toxicity of crude glycerol for direct use.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.632-637
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• 2017

This study was conducted to determine the minimal processing characteristics of four vegetables (brown mustard, kale, red beet and red lettuce) for wrapping (Ssam). Prior to evaluation, the vegetable leaves were cut, washed, and packaged. The texture, weight loss, browning index, pH, gas concentrations ($O_2$ and $CO_2$), microbial growth, and organoleptic qualities of the leaves were assessed at $10^{\circ}C$ for 7 days. The cutting strength of red beet was significantly different among leaves. The initial springiness of brown mustard was the lowest (0.98%). The weight loss varied between 0.24 to 4.77%, pH ranged from 6.00 to 6.95, and browning index increased to 0.95 during storage. Changes of gas composition were lower in cut leaf than whole leaf. Aerobic bacteria (4.9-8.0 log CFU/g), yeast (not detected), mold (-3.5 log CFU/g), and total coliforms (5.0-8.0 log CFU/g) were assessed in the samples. Thus, overall quality of kale and red beet leaves with minimal processing showed satisfactory results when stored for 7 days.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.277-282
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• 1999

This study was carried out to clarify the microorganisms which participated in the fermentation of kanjang. The changes in the viable cell counts of total aerobic bacteria, lactic acid bacteria and yeasts for raw soybean, soybean during cooking, meju during cultivation, and kanjang mash during maturing were investigated along with the changes in components during those periods. Lactic acid bacteria that were found to be $6{\times}10^2\;CFU/g$ in raw soybean were disappeared after cooking process, but total aerobic bacteria were diminished from $1.9{\times}10^6\;CFU/g$ to $10^2\;CFU/g$. Aerobic bacteria of inner and outer parts of meju increased to more than $10^9\;CFU/g$. The higher viable cell counts of lactic acid bacteria in the inner parts of meju were observed than those in outer ones. On the contrary, significantly higher viable cell counts of yeasts in the outer parts of meju were found. Total nitrogen content and color density of kanjang increased by using meju with extended cultivation periods. No significant differences were observed in microbial counts between kanjang mash with aeration and non-aeration during kanajng mash maturing.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.54-61
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• 2014

This study was conducted to investigate the effect of Actinomyces sp. and Bacillus sp., United States granular microorganisms and Japan granular microorganisms on turfgrass growth and thatch decomposing of creeping bentgrass in golf course by measuring turf color index, chlorophyll index, thatch content of soil, root length, turf density and chemical properties and thatch content of soil. Fertilizer treatment was designed as follows; control(CF; compound fertilizer), microorganism medium(M; CF+M), microorganism medium and livestock manure fertilizer(M-L; CF+M+LMF), microorganism medium, livestock manure fertilizer and amino acid liquid fertilizer(M-L-A; MM+LMF+ALF), United States granular microorganisms(USGM; CF+USGM), Japan granular microorganisms(CF+JGM). Soil properties investigated after experiment was scarcely affected by applied fertilizers in root zone of creeping bentgrass. The turf color index and chlorophyll index of M, M-L, M-L-A, USGM, JGM treatment were higher than those of CF. The turfgrass root in M-L treatment was longer than others. The thatch content of soil in M treatment was longer than others. The thatch content of M was decreased than that of CF by 6.8%. These was suggested that application of M induced the development of quality and growth of creeping bentgrass by assisting turfgrass growth and thatch decomposing.

• Korean Journal of Pharmacognosy
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• v.47 no.2
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• pp.158-164
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• 2016

This study was conducted to verify the potential of Allium hookeri to control blood glucose metabolism in diabetes model. We fed the experimental diets(ALE, ARE) supplemented with the extract of Allium hookeri leaf or root at 1% of diet to the diabetic mice (C57BLKS/J, db/db) for 8 weeks. Hetero and control mice were fed the control diet without any extract of Allium hookeri leaf or root. At 8th week of feeding the diets, we measured body weight, blood glucose, HbA1c, and plasma insulin levels and conducted an oral glucose tolerance test (OGTT) and staining insulin immunoreactive cells in islets of pancreas. ARE group treated with the root of A. hookeri showed significantly lower blood glucose levels than the Cont group at 120 min in the OGTT. However, HbA1c level was significantly reduced in both ALE and ARE groups, and higher serum insulin levels and increased density of insulin immunoreactive cells compared with the Cont group were found in these 2 groups. Based on these results, A. hookeri is considered to be effective in improving glucose tolerance by partially affecting insulin secretion and it may be used to prevent and treat diabetic disease.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.314-321
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• 2013

Photodynamic therapy(PDT) has been recommended as an alternative therapy for various diseases including microbial infection. The aim of the present study is to evaluate the antimicrobial effect of PDT using a photofrin and home made 630 nm Light emitting diode(LED) against Staphylococci. To examine the antimicrobial effect of photofrin-mediated PDT against Staphylococcus aureus and Staphylococcus epidermidis colony forming units(CFU) quantification, and bacterial viability using flow cytometry were formed. The CFU quantification results of S. aureus and S. epidermidis were 1 cfu/ml and 16 cfu/ml of average, respectively, after PDT application with photofrin of $50{\mu}g/m{\ell}$ and 630 nm LED and energy density of $18J/cm^2$. In addition, S. aureus and S. epidermidis isolates yielded forward-scatter (FSC) and fluorescence intensity (FI) differences on flow cytometry (FCM) after PDT. S. aureus and S. epidermidis cell size(FSC) increased 8.96% and 5.55% respectively, after PDT. Also the numbers of dead cell of S. aureus and S. epidermidis were a 39% and 61% incerased. These results suggest that photofrin-mediated PDT can be an effective alternative treatment for antibacterial therapy.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.105-108
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• 2011

The increased concern for the security of the oil supply and the negative impact of fossil fuels on the environment, particularly greenhouse gas emissions, has put pressure on society to find renewable fuel alternatives. Compared to the traditional biofuel, ethanol, higher alcohols offer advantage as gasoline substitutes because of their higher energy density and lower hygroscopicity. For this reason, microbial fermentation is known as potential producers for sustainable energy carriers. In this study, bacterial responses including cellular and molecular toxicity were studied in three different microorganisms, such as Escherichia coli, Clostridium acetobutylicum, and Saccharomyces cerevisiae. In this study, it was analyzed specific stress responses caused by ethanol and buthanol using four different stress responsive genes, i.e. fabA, grpE, katG and recA. The expression levels of these genes were quantified by semi-quantitative reverse transcription-PCR. It was found that four genes have shown different responsive patterns when E. coli cultures were under stressful conditions caused by ethanol and buthanol, respectively. Therefore, in this study, the stress responsive effects caused by these alcohols and the extent of each stress response can be analyzed using the expression levels and patterns of different stress responsive genes.

• Korean Journal of Ecology and Environment
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• v.34 no.2 s.94
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• pp.119-125
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• 2001

Total bacterial density was investigated in the main stream and tributaries of the Kyongan Stream and inlet parts of Paltang Reservoir from September 2000 to February 2001 by acridine orange direct count (AODC) method. Total bacterial number in the Kyongan Stream was mainly under influence of the effluent discharge of sewage wastewater treatment plant (SWTP) located in the upstream or downstream. Decreasing rate with water flowing distance (km) in the main stream is $0.13\;{\time}\;10^6$ cells/ml, and it was estimated to much accumulating quantity on the stream bed during transport to downstream. Average values of total bacterial number in September${\sim}$October, November and December${\sim}$February were range $1.74{\sim}3.10{\time}10^6$, $1.86{\sim}7.30{\time}10^6$ and $4.56{\sim}8.75{\time}10^6$cells/ml, respectively, and were high at low temperature than that of high temperature period. Total bacterial number was more abundant at below $10^{\circ}C$ with $2.1{\sim}3.0$ folds than at above $10^{\circ}C$. Water quality by total bacterial number was classify to eutrophic and the potential of wastewater treated effluent for the microbial contamination assessed to very high. The results of this study indicate that the management of point source, SWTP effluent, is urgent to mitigate bacterial impact of Paltang Reservoir as well as the Kyongan Stream.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.249-255
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• 2015

Trichoderma spp. were famous fungi used for turfgrass management in golf course. This study was conducted to evaluate effects of two microbial fertilizers containing Trichoderma harzianum and T. atroviride on the growth and quality of creeping bentgrass with turf color index, chlorophyll index, root length, shoot number, clipping yield and nutrient content. Treatments were designed as follow; non-fertilizer (NF), control fertilizer (CF), T. harzianum (TH), and T. atroviride (TA). Chlorophyll index and root length of TH and TA were increased than these of CF and shoot number and content and uptake of nitrogen (N) of TA higher than these of CF. The N content in turfgrass tissue was significantly related to shoot number, root length and N uptake (P<0.05) and shoot number was positively relate to chlorophyll index (P<0.05). These results indicated that application of Trichoderma harzianum and T. atroviride improved a growth and quality of creeping bentgrass by promoting N uptake.