• Korean Journal of Microbiology
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• v.54 no.4
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• pp.384-397
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• 2018

The aim of this study is to screen the strains of Bacillus spp. possessing safety, probiotic activity, and so on, which can be utilized as probiotic resource for using the feed and supplement food of companion animal. About 300 isolates were isolated from traditional Korean sauces, four isolates that did not have or produce the six kinds of B. cereus type vomiting and diarrhea toxin genes, ${\beta}$-hemolytic, and three kinds of carcinogenic enzymes were selected. Antibiotic gene retention, cell surface hydrophobicity, antibiotic sensitivity, and glucose utilization were analyzed for four isolates, and finally SRCM 100731 was selected. SRCM 100731 was named as Bacillus amyloliquefaciens SRCM 100731 16S rRNA sequencing analysis, and carried out optimization of cell growth for industrial applications such as pet food and feed. The effects of 14 different components on cell growth were investigated and three significant positive factors, molasses, sodium chloride, and potassium chloride were selected as the main factors based on a Plackett-Burman design. In order to find out optimal concentration on each constituent, we carried out central composite design. The predicted optimized concentrations were 7% molasses, 1.1% sodium chloride, 0.5% potassium chloride. Finally, an overall about 7-fold increase in dry cell weight yield ($12.6625{\pm}0.0658g/L$) was achieved using the optimized medium compared with the non-optimized medium ($1.8273{\pm}0.0214g/L$). This research is expected to be highly utilized in the growing pet industry by establishing optimal cultivation conditions for industrial application as well as screening Bacillus amyloliquefaciens SRCM 100731 as probiotic resource for companion animal.

• KSBB Journal
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• v.8 no.5
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• pp.438-445
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• 1993

Raw cow manure was treated by a 4-step integrated system with phase separation anaerobic digestion and algal culture. When the first methane fermentation was performed by the effluent from the acid fermenter with retention time of 4 days, the elrerage blogas production rate was 977m1/1 culture/day Gas productivity compared to conventional single-stage anaerobic digestion increased up to 31.4%. As the 2nd methane fermenter was fed by the effluent from the first methane fermenter with 4 days of retention time, average amount of 428m1/1 culture/day of biogas was produced. The reduction rate of COD in the effluent from the acid fermenter, the 1st and the 2nd methane fermenter were 71.8%, 42.6% and 24.0% respectively. Finally, we examined algal treatment process for the effluent from the 2nd methane fermenter. A semi-continuous culture of Chlorella sp. PSH3 was conducted by feeding the effluent with retention time of 10days. In this process, the production rate of algal biomass and COD reduction rate were averaged 1.8g/1 culture/day(2.8$\times$106 cells/ml) and 73%, respectively. Through the 4-setp treatments, the total chemical oxygen demand was reduced from 51,300ppm to 85ppm. Therefore, the reduction rate of total chemical oxygen demand reached about 99.8%. The results indicate that the integrated system could be applicable for treatment of organic wastes, concurrently producing biogas and algal biomass.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.187-191
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• 1998

For efficient and economical production of Btrc,illus tlz~rr.ingi~r1~sstirsa in NT0423 as amicrobial-control agents, a new culture medium and culture condition were developed. Five mediadesignatzd as SWI I , SW14, SW23. SW32 and SW4I were prepared ~ : i t hv arious mixture ratio ofsoybean cake and wheat bran. It was founcl that in terms of the cell growth rate and development ofsporulation of B, thrri.il~girrl.sis strain NT0423 in all SW culture media were more efficient than those inGYS and in LB media. Total cell number in all SW media showed similar values, hut SW32 lnediilm wasthe most efficient in the development of spore, which amo~~ntetod 3.7 x 10XC FUImI. Also. at the pHranging frorn 6.2 to 7.3 in the mediiun~ no ad\:erse effect was not made in the culture of B. thur-ingicnsisstrain NT0423. The optimal volume (%) of SW32 mecliuni in a 5 1 fernientor was determined as 4 8\rolume of total niediuni. resulting ill growth (4.2 x 1OTCFUlrnl) of H. t1~~irir1,yirrz.ssit.vr ain NT0423. As H.t l i ~ t r i t ~ g iw~ a~s~ csuil~tu rcd in the shakc-flash and 5 1 fcrnientor. bacterial cells were yielded to 1 X 10"CFUIml and 5 x I O1oCFLJlml.FUIml and 5 x I O1oCFLJlml.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.3
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• pp.460-473
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• 2015

This study aimed to create a standardized recipe using three cultivars of tomatoes (Chal-tomato, Daejeo-tomato, Blacktomato) and select an appropriate tomato for producing tomato Jangajii through quality and sensory evaluation. With regard to the proximate composition of tomato Jangajii, moisture and ash contents of Chal-tomato were highest in the early stage of storage, whereas moisture, crude protein and ash contents of Black-tomato were highest in the final stage of storage. Daejeotomato showed minimal changes in pH, but showed the highest salt and sugar contents. L value increased with increasing storage time and then decreased thereafter (p<0.001). The a and b values decreased with increasing storage time and then increased thereafter (p<0.001). The reducing sugar content increased with increasing storage time and then decreased thereafter (p<0.001). With regard to Daejeo-tomato, hardness was the highest (p<0.001), and total microbial counts were lowest (p<0.001). Daejeo-tomato showed the lowest activities of PME as a softening enzyme and PG. For sensory properties, Daejeo-tomato showed a relatively high preference for all items except aroma. Based on the above results, Daejeo-tomato Jangajii showed superior quality characteristics and high preference in general among tomato Jangajii from all three cultivars of tomatoes. Therefore, Daejeo-tomato Jangajii is useful as low-sodium tomato Jangajii in light of quality characteristics and preference.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.85-94
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• 2015

RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) is the most important explosive contaminant, both in concentration and in frequency, at military shooting ranges in which green technologies such as phytoremediation or constructed wetlands are the best option for mitigation of explosive compounds discharge to the environment. A study was conducted with two identical lab-scale plug flow constructed wetlands planted with Amur silver grass to treat water artificially contaminated with 40 mg/L of toxic explosive compound, RDX. The reactor was inoculated with or without RDX degrading mixed culture to evaluate plant-microorganism interactions in RDX removal, transformation products distribution, and kinetic constants. RDX and its metabolites in water, plant, and sediment were analyzed by HPLC to determine mass balance and kinetic constants. After 30 days of operation, the reactor reached steady-state at which more than 99% of RDX was removed with or without the mixed culture inoculation. The major transformation product was TNX (Trinitroso-RDX) that comprised approximately 50% in the mass balance of both reactors. It was also the major compound in the plant root and shoot system. Acute toxicity analysis of the water samples showed more than 30% of toxicity reduction in the effluent than that of influent containing 40 mg/L of RDX. In the Amur silver grass mesocosm seeded with the mixed culture, the specific RDX removal rate, that is 1st order removal rate normalized to plant fresh weight, was estimated to be 0.84 kg⁻¹ day⁻¹ which is 16.7% higher than that in the planted only mesocosm. Therefore, the results of this study proved that Amur silver grass is an effective plant for RDX removal in constructed wetlands and the efficiency can be increased even more when applied with RDX degrading microbial consortia.

• Journal of Environmental Health Sciences
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• v.35 no.5
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• pp.393-401
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• 2009

We isolated and identified a microorganism which was excellent for ammonia oxidation in the biological control of ammonia gas in odor producing materials from organic composting. The isolated strain was tested for growth characteristics and ammonia elimination efficiency under various conditions of temperature, pH, carbon concentration and ammonia concentration. The strain was isolated from a culture broth used in a $NO_2$ producing test with Griess-Ilosvay reagent. The results of 16S rRNA sequence from the isolated strain by using BLANST (Basic Local Alignment Search Tool) and confirming RDP (Ribosomal Database Project II) and ERRD (The European Ribosomal RNA Database) indicate that the strain is related to Delftia sp. UV-Spectrophotometer (Shimadzu, UVmini-1240) was used as a microbial growth test by measuring turbidity on OD660nm and ammonia concentration was measured by Spectrophotometer (HACH, DR-4000). The optimum growth culture conditions of the ammonia oxidizer Delftia sp. were $30^{\circ}C$, pH 7, glucose concentration 1.00% and $(NH_4)_2SO_4$ 0.5 g/l. Ammonia elimination efficiency was over 94% under the same conditions.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1244-1251
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• 2020

Phospholipase A₂ (PLA₂) from Streptomyces violaceoruber is a lipolytic enzyme used in a wide range of industrial applications including production of lysolecithins and enzymatic degumming of edible oils. We have therefore investigated expression and secretion of PLA₂ in two workhorse microbes, Pichia pastoris and Escherichia coli. The PLA₂ was produced to an activity of 0.517 ± 0.012 U/ml in the culture broth of the recombinant P. pastoris. On the other hand, recombinant E. coli BL21 star (DE3), overexpressing the authentic PLA₂ (P-PLA₂), showed activity of 17.0 ± 1.3 U/ml in the intracellular fraction and 21.7 ± 0.7 U/ml in the culture broth. The extracellular PLA2 activity obtained with the recombinant E. coli system was 3.2-fold higher than the corresponding value reached in a previous study, which employed recombinant E. coli BL21 (DE3) overexpressing codon-optimized PLA₂. Finally, we observed that the extracellular PLA₂ from the recombinant E. coli P-PLA₂ culture was able to hydrolyze 31.1 g/l of crude soybean lecithin, an industrial substrate, to a conversion yield of approximately 95%. The newly developed E. coli-based PLA₂ expression system led to extracellular production of PLA₂ to a productivity of 678 U/l·h, corresponding to 157-fold higher than that obtained with the P. pastoris-based system. This study will contribute to the extracellular production of a catalytically active PLA₂.

• Korean Journal of Human Ecology
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• v.4 no.1
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• pp.79-92
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• 2001

E. coli transformants EC3, EC4. and EC6. harboring citron oil degrading pathway genes, were co-cultured in M9 media with citron oil as a sole carbon source at 28$^{\circ}C$. Each co-culture(EC3+EC4, EC3+EC6, EC4+EC6 and EC3+EC4+EC6) showed three to four times higher cell growth than each transformant single culture. Microbial conversion products from the co-cultures were determined by GC-MS. Linalool. 4-terpineol and ${\alpha}$-terpineol were the major common products from co-cultures. Various minor products also were detected and important in flavor characteristics of cultures.

• Korean Journal of Plant Tissue Culture
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• v.21 no.6
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• pp.357-362
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• 1994

Chitinases and $\beta$-1,3-glucanases are believed to be important in defending plane against pathogens. Here, we investigated the expression of chitinase(s) in Arabidopsis thaliana cell suspension culture system in response to ethephon (2-chloroethyl phosphonic acid) which produces ethylene or a microbial elicitor, a bacterial pectin-degrading enzyme, $\beta$-1, 4-endopolygalactronic acid Iyase (PGA Iyase), treatment. Chitinase activity was measured either by radio chemical assay using $^3$H-labeled regenerated chitin as substrate or western blot analysis using antibody raised against tobacro chitinase(S). With 1 mg/mL of ethephon or 100 m units/mL of elicitor treatment, maximum levels of activity were reached after 48h. We also investigated distribution of chitinase activity in seedlings, leaves, and root of A. thaliana and found that root have the highest chitinase activity.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.361-365
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• 2011

To evaluate the indoor air quality of food manufacturing plants, the presence of viable bacteria and fungi was assessed in the indoor air of the facilities at which 9 food items were manufactured. Air samples were collected from the general zone, low clean zone and clean zone of each factory with an air sampler, in combination with plate counts agar using for bacteria, and dichloran-glycerol agar for fungi. The samples were incubated at $25^{\circ}C$ for 4 to 7 days. After culture, the colony forming units (CFU) on each plate were counted and corrected with a positive hole conversion table. The average concentration of bacteria was $2.2{\times}10^3\;CFU/m^3$ in the general zone, $1.2{\times}10^3\;CFU/m^3$ in the low clean zone and $7.3{\times}10^2\;CFU/m^3$ in the clean zone. The average concentration of fungal microbes was $2.5{\times}10^3\;CFU/m^3$ in the general zone, $2.6{\times}10^3\;CFU/m^3$ in the low clean zone, and $2.0{\times}10^2\;CFU/m^3$ in the clean zone. No meaningful differences were detected between the general zone and the low clean zone, but the clean zone had significantly lower concentrations than the other zones. Additionally, the identification of the fungi was performed according to morphological method using a giant culture and slide culture. The fungi were identified as belonging to 18 genera, and the genera Cladosporium(33%), Penicillium(29%) and Aspergillus(26%), predominated. Aspergillus isolates were identified to species level, and A. ochraceus, a mycotoxigenic species, was identified. As part of the effort to control the quality of the indoor air of food manufacturing plants, our results show that continued studies are clearly warranted.