• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.973-977
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• 2013

These studies were attempted to investigate the change of microbial community of anode of microbial fuel cell using swine wastewater in the enrichment step with the lapse of time. Microbial fuel cells enriched by a 1 : 1 mixture of anaerobic digestive juices of the sewage treatment plant and livestock wastewater. Enrichment culture step was divided into three stages to indentify the microorganisms. It was separated by each lag phase, exponential phase, and stationary phase. These steps were determined by the change of the current value. The current after enrichment was generated about $0.84{\pm}0.06mA$. We were cut out the different 17 bands in the DGGE fingerprint gel to do sequencing. The bands which the concentration was increasing or newly appearing with the lapse of time were included for this study. In the lag and exponential phase, Clostridium, Rhodocyclaceae, Bacteriodetes, and Uncultured bacterium etc. were detected. There were in the stationary phase Geobacter sp., Rhodocyclaceae, Candidatus, Nitrospira, Flavobactriaceae and uncultured bacterium etc. Geobactor among microorganisms detected in this study is known as the Electrochemically active microorganisms. It may include electrochemically active microorganisms to be considered as electrical activity microorganisms.

• 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.23 no.4
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• pp.343-347
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• 2008

Recently, Sunshik has been issued because of easy-cook and well-being food. Sunshik basically was made of the heated cereals. Amount of spore-forming Bacillus cereus was detected and it has been caused some problem of food safety. B. cereus was isolate from 57 out of 161 Sunshik samples resulting in the isolation rate of 35.4%. Quantitative analysis of 57 samples showed that 21 samples were less than 100 CFU/g, 33 samples were between 100 and 1,000 CFU/g and distinctively even 3 (1.9%) samples had over 1,000 CFU/g. Typical morphology of B. cereus isolated from Sunshik was observed on MYP agar and then further characteristics was identified by using VITEK 2 (Biomeriux, France). 53 strains out of 57 strains isolated from Sunshik (about 93.0%) produced diarrheal enterotoxin in brain heart infusion broth which was detected by the Bacillus cereus enterotoxin reversed passive latex agglutination test kit (Oxoid England). The D-values of the B. cereus spores were $75^{\circ}C$ (37.1mim), $80^{\circ}C$ (22.5mim), $85^{\circ}C$ (4.9mim), and $90^{\circ}C$ (3.1mim) respectively. The Z-value was calculated $12.8^{\circ}C$ in Sunshik sample inoculated with B. cereus. Therefore, the management of B. cereus in Sunshik is required for the food-safety.

• Korean Journal of Food Science and Technology
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• v.13 no.3
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• pp.209-218
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• 1981

Free fatty acid and total saponin, which were extracted from the spent media and colony of the strain Phizopus delemar Rh-1, were qualitatively examined by GLC and spectroscopic methods and compared with these of intact ginseng media. The 18, 18, and 14 free fatty acids were respectively identified from the control, spent media and colony. Among them, $iC_{12:0},\;C_{16:2},\;C_{17:0},\;C_{18:3}\; and\;C_{20:0}$ acids were not detectable from the colony. In add ition, $C_{16:2}\;and\;C_{20:0}$ peaks were rot found in the spent media and control, respectively. The isible absorption spectra of free fatty acids and total saponins in the control, spent media and colony were invariable. In contrast, however, the infrared and ultraviolet absorption spectra showed significant spectral variations, particularly in the it finger-print region, demonstrating that the ginseng components were considerably utilized by the strain Rhizopus delemar Rh-1.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.486-491
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• 2015

The potential of applying cold plasma (CP) treatments to improve microbiological safety of powdered products has been investigated using infant milk powder (IMP) and onion powder (OP). Among the different kinds of CP-forming gases, He-$O_2$ (99.8:0.2) gas mixture and He gas were most effective in reducing the number of Cronobacter sakazakii in IMP and Bacillus cereus spores in OP, respectively. C. sakazakii counts in IMP decreased by $0.9{\pm}0.1{\log}\;CFU/g$ after CP treatment, and the extent of C. sakazakii inhibition increased in a time-dependent manner. CP treatment at 900 W for 20 min reduced the number of B. cereus spores by ~0.4 log spores/g. Treatments that integrated CP with microwave (MW-CP treatment) as well as those that integrated CP with heat and microwave (H-MW-CP treatment) resulted in a 90% reduction in the number of spores in OP. Thus, CP treatments demonstrated potential for decontaminating foodborne pathogens from powdered products, in combination with heat for improved effect.

• The Korean Journal of Mycology
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• v.42 no.3
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• pp.247-252
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• 2014

The study was conducted to investigate the effect of shading treatment on the uniform primordium formation and development of fruit body during incubation of major cultivated oyster mushrooms (Pleurotus ostreatus). Oyster mushrooms cultivars Suhan No. 1 and Gonji No. 7 were incubated while shading during different times in the incubation room wherein temperature of $20^{\circ}C$ was maintained. Substrate temperature during incubation was increased to $24{\sim}25^{\circ}C$ in 11~12 days for Suhan No. 1 and to $25{\sim}26^{\circ}C$ in 11~12 days for Gonji No. 7 regardless of shading times. The $CO_2$ generation was the highest as 9~11% for Suhan No. 1 and 9~10% for Gonji No. 7 at the time of temperature increase the highest, while $O_2$contents became decreased, thus constructed good environment for the growth of hyphae. Therefore, ratio of ununiformal primordia formation was reduced by 20% as against control for Suhan No. 1 and by 13% for Gonji No. 7 when shading was applied from $10^{th}$ day of inoculation with no difference in fruit body yield.

• Journal of Life Science
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• v.18 no.1
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• pp.103-108
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• 2008

An agar-degrading marine bacterium, strain AS-1 was isolated from the seawater. The strain AS-1 was identified as Sphingomonas paucimobilis (90% probability) by VITEK. The optimum medium for agarase activity of the isolated strain was determined to be marine medium, marine broth 2216 containing 0.1% agar as carbon source. An extracellular agarase was purified 104-fold from the culture supernatant by ammonium sulfate precipitation, ion exchange chromatography and gel filtration methods. The molecular weight of the purified enzyme was estimated to be 80 kDa by SDS-PAGE. The optimum pH and temperature for activity were 7.0 and $40^{\circ}C$, respectively. Antioxidative activity of the strain AS- was 72% in the supernatant cultured for 12 h. The culture supernatant of the strain AS-1 showed antibacterial activity against bacteria causing putrefaction and food poisoning such as Escherichia coli, Staphylococcus aureus and Proteus vulgaris. However, the cell growth of the lactic aicd forming strain, Lactobacillus plantarium was promoted by the treatment of 10% culture supernatant of an agar-degrading strain.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.555-562
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• 1997

The characteristics of mash qualities of takju prepared by using different nuruk (Korean-style bran koji) such as Mucor racemosus nuruk, Rhizopus japonicus nuruk, Aspergillus oryzae nuruk, Aspergillus kawachii nuruk and traditional nuruk were investigated during fermentation. At the begining of fermentation, ethanol content was in the range of $2.0{\sim}3.0%$. However, it increased to $8.2{\sim}12.6%$ after 16 days of fermentation. Takju made from Rhizopus japonicus nuruk showed higher ethanol content than treated otherwise. pH of takju made from Rhizopus japonicus nuruk showed higher value the others. Total acids were $0.15{\sim}0.20%$ at the begining of fermentation, and it increased to $0.086{\sim}1.57%$ after 16 days of fermentation. Total sugar were $16.64{\sim}17.62%$ at the begining of fermentation, but decreased to below 7.00% after 16 days of fermentation. Rhizopus japonicus nuruk showed the lowest level of total sugar content. Except ethanol, iso-amyl alcohol and iso-butyl alcohol were major part of minor alcohol in the mash of takju. Higher concentration of iso-amyl alcohol, iso-butyl alcohol and n-propyl alcohol were found in the mash of Rhizopus japonicus nuruk whereas the level of phenylethyl alcohol was high in the mash of traditional nuruk. Fusel oil was $0.002{\sim}0.411\;mg/mL$ during fermentation.

• KSBB Journal
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• v.24 no.2
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• pp.163-169
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• 2009

Lovastatin (also known as Mevinolin, Mevacor, and Monacolin K), an inhibitor of the HMG-CoA reductase produced by Aspergillus terreus and other fungi, is used to reduce serum cholesterol levels in human beings. It is derived biosynthetically from two polyketides. One of these is a nonaketide that undergoes cyclization at a hexahydronaphthalene ring system, and the other is a simple diketide, 2-methylbutyrate. Two primer pairs were designed based on the amino acid sequences of lovastatin polyketide synthase and lovastatin diketide synthase for the PCR screening of lovastatin-producing strains. Among the seven selected strains, SJ-2 evidenced the highest level of lovastatin production in both liquid and solid cultures. Soybeans with SJ-2 were treated via 1 hour of heat shock at $30^{\circ}C$ for the mass production of lovastatin. The heat-treated soybeans were inoculated on rice bran and the koji extract was obtained after 15 days of incubation. It yielded the highest level of lovastatin production among the strains, and also evidenced 75% inhibition activity against HMG-CoA reductase. We developed an efficient PCR screening method for lovastatin-producing strains, using lovastatin biosynthesis genes.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.442-446
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• 2007

From the rhizoplane and rhizosphere of pepper, tomato, lettuce, pasture, and grass, unsoluble inorganic phosphate solubilizing bacterial strains were isolated using plate base assay on Pikovskaya's medium. Two strains, CL-1 and CL-2, which produced largest halo on plates (indicative of phosphate solubilization)were selected for further studies. Based on these biochemical and 16S rRNA analysis strains CL-1, CL-2 were found to be as species of Pseudomonas sp. and Kluyvera sp., respectively. In broth assay Pseudomonas sp. CL-1 and Kluyvera sp. CL-2 solubilized insoluble phosphate by 193.4 mg and $493.6P\;mg\;L^{-1}$, respectively after $3^{rd}$ day inoculation. These effecient phosphate solubilizing bacteria have a potential to be developed as microbial based fertilizer in future.