• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1252-1260
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• 2020

(R)-2-(4-hydroxyphenoxy)propionic acid (HPOPA) is a key intermediate for the preparation of aryloxyphenoxypropionic acid herbicides (R-isomer). In order to improve the HPOPA production from the substrate (R)-2-phenoxypropionic acid (POPA) with Beauveria bassiana CCN-A7, static cultivation and H₂O₂ addition were attempted and found to be conducive to the task at hand. This is the first report on HPOPA production under static cultivation and reactive oxygen species (ROS) induction. On this premise, the cultivation conditions and fermentation medium compositions were optimized. As a result, the optimal carbon source, organic nitrogen source, and inorganic nitrogen source were determined to be glucose, peptone, and ammonium sulfate, respectively. The optimal inoculum size and fermentation temperature were 13.3% and 28℃, respectively. The significant factors including glucose, peptone, and H₂O₂, identified based on Plackett-Burman design, were further optimized through Central Composite Design (CCD). The optimal concentrations were as follows: glucose 38.81 g/l, peptone 7.28 g/l, and H₂O₂ 1.08 g/l/100 ml. Under the optimized conditions, HPOPA titer was improved from 9.60 g/l to 19.53 g/l, representing an increase of 2.03-fold. The results obtained in this work will provide novel strategies for improving the biosynthesis of hydroxy aromatics.

• 한국식품영양과학회지
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• 제23권5호
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• pp.845-848
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• 1994

The fermenting conditions for acetic acid production with Acetobacter sp. FM-10 which could grow in the medium containing 10% ehtanol were investigated. Initial concentration of acetic acid in broth medium affected greatly to the fermentation speed. For example , the acetic acid production increased proportionally by the increasing of initial concentration was higher that 1.0%. When the cultivation was started with broth medium containing 5% ethanol, the additional adding ethanol during the fermentation was not significantly increased the acidity of the medium. The acidity of the medium containing 10% ethanol was reached to 8.3% after shaking than static cultivation by about 10 days with 150 rpm shaking speed. Acetic acid production with shaking cultivation was faster the static cultivation by abot 10 days under the same condition except shaking. In acetic acid fermentation with the batch style fermentor , the optimum fermentation condition was 700 rpm of agitation speed and 5L/min air flow rate in 3L culture medium .

• 대한예방한의학회지
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• 제1권1호
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• pp.59-75
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• 1997

After examining the viewpoints of the mental cultivation of The yellow Emperor's Internal Bible(內徑), from the viewpoints of The yellow Emperor's Internal Bible, I studied the principles and methods of the mental cultivation(精神養生) which the Taoism School, the Confusian School and the past physicians proposed. And I studied the methods of mental cultivation of the child, the woman and the old by the differences of ages and sex. At the subject of health preservation(養生學) on the basis of concept of relevant adaptation of man to nature(天人相應思想), the mental cultivation(精神養生) was regard more important than the body cultivation(肉體養生) and it was considered that the success of health preservation depended on the state of mind. the basic principles of the mental cultivation is achivement of the mental internal keeping(精神內守) through the state of peace and tranquility without avarice and wild fancy(恬憺虛無). The ways of mental cultivation of the Taoism School, the Confusian School and the past physicians were in the category of The yellow Emperor's Internal Bible. 4. In the previous Jin dynasty(先秦時代), the important theoretical bases and practices to mental cultivation were made. In the Han dynasty(漢時代), the physicians attached importance to mental treaments. During the time from Sui dynasty to Tang Dynasty(隋唐時代), the mental cultivation was made perfect theoretically. During the Period from Song dynasty to Yuan Dynasty(宋元時代), Many methods of mental cultivation were newly created. During the Ming and the Qing Dynasties(明淸時代), the theory of health preservation and the methods of mental treaments were embodied. 5. Studying the mental cultivation by the differences of ages, the childhood(小兒期) is the spring of life. So the mental cultivation of this period put importance to the cultivation of Sh ng(養生). And the youth(靑年期) is the summer of life. So the mental cultivation of this period pill importance to the cultivation of Ch'ang(養長). And the middle age(中年期) is the autumn of life. So the mental cultivation of this period put imporance to the cultivation of Shou(養收). And the old age(老年期) is the winter of life. So the mental cultivation of this period put importance to the cultivation of Tsang(養藏). Studying the mental cultivation by the differences of sex, the man must do the mental cultivation through the dynamic nature(性情) of Yang(陽) and the woman must do the mental cultivation through the static nature of Yin(陰).

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.955-956
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• 2012

• 한국환경농학회지
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• 제31권3호
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• pp.205-211
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• 2012

BACKGROUND: Generally, nitrogen (N) fertilization higher than the recommended dose is applied during vegetable cultivation to increase productivity. But higher N fertilization also increases the concentrations of nitrate ions and nitrous oxide in soil. In this experiment, the impact of N fertilization was studied on nitrous oxide ($N_2O$) emission to standardize the optimum fertilization level for minimizing $N_2O$ emission as well as increasing crop productivity. Herein, we developed $N_2O$ emission inventory for upland soil region during red pepper and Chinese milk vetch cultivation. METHODS AND RESULTS: Nitrogen fertilizers were applied at different rates to study their effect on $N_2O$ emission during red pepper and Chinese milk vetch cultivation. The gas samples were collected by static closed chamber method and $N_2O$ concentration was measured by gas chromatography. The total $N_2O$ flux was steadily increased due to increasing N fertilization level, though the overall pattern of $N_2O$ emission dynamics was same. Application of N fertilization higher than the recommended dose increased the values of both seasonal $N_2O$ flux (94.5% for Chinese cabbage and 30.7% for red pepper) and $N_2O$ emission per unit crop yield (77.9% for Chinese cabbage and 23.2% for red pepper). Nitrous oxide inventory revealed that the $N_2O$ emission due to unit amount of N application from short-duration vegetable field in fall (autumn) season (6.36 kg/ha) was almost 70% higher than that during summer season. CONCLUSION: Application of excess N-fertilizers increased seasonal $N_2O$ flux especially the $N_2O$ flux per unit yield during both Chinese cabbage and red pepper cultivation. This suggested that the higher N fertilization than the recommended dose actually facilitates $N_2O$ emission than boosting plant productivity. The $N_2O$ inventory for upland farming in temperate region like Korea revealed that $N_2O$ flux due to unit amount of N-fertilizer application for Chinese cabbage in fall (autumn) season was comparatively higher than that of summer vegetables like red pepper. Therefore, the judicious N fertilization following recommended dose is required to suppress $N_2O$ emission with high vegetable productivity in upland soils.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.83-88
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• 2003

A cellulose-producing strain isolated from rotten apples was identified as Gluconacetobacter hansenii based on its physiological properties and the 16S rDNA complete sequencing method, and specifically named Gluconacetobacter hansenii PJK. The amount of bacterial cellulose (BC) produced by G. hansenii PJK in a shaking incubator was 1.5 times higher than that produced in a static culture. The addition of ethanol to the medium during cultivation enhanced the productivity of bacterial cellulose, plus the supplementation of 1% ethanol into the culture medium made the produced BC aggregate into a big lump and thus protected the bacterial-cellulose-producing G. hansenii PJK cells in the shear stress field from being converted into non-cellulose-producing (Cel) mutants. Cells subcultured three times in a medium containing ethanol retained their ability to produce BC without any loss in the production yield.

• Mycobiology
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• 제46권4호
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• pp.396-406
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• 2018

A newly isolated white rot fungal strain KU-RNW027 was identified as Trametes polyzona, based on an analysis of its morphological characteristics and phylogenetic data. Aeration and fungal morphology were important factors which drove strain KU-RNW027 to secrete two different ligninolytic enzymes as manganese peroxidase (MnP) and laccase. Highest activities of MnP and laccase were obtained in a continuous shaking culture at 8 and 47 times higher, respectively, than under static conditions. Strain KU-RNW027 existed as pellets and free form mycelial clumps in submerged cultivation with the pellet form producing more enzymes. Fungal biomass increased with increasing amounts of pellet inoculum while pellet diameter decreased. Strain KU-RNW027 formed terminal chlamydospore-like structures in cultures inoculated with 0.05 g/L as optimal pellet inoculum which resulted in highest enzyme production. Enzyme production efficiency of T. polyzona KU-RNW027 depended on fungal pellet morphology as size, porosity, and formation of chlamydospore-like structures.

• 한국환경과학회지
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• 제23권5호
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• pp.895-902
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• 2014

Bacterial cellulose (BC) has played important role as new functional material for food industry and industrial products based on its unique properties. The interest in BC from static cultures has increased steadily in recent years because of its potential for use in medicine and cosmetics. In this study, we investigated culture condition for BC production by Acetobacter sp. F15 in static culture. The strain F15, which was isolated from decayed fruit, was selected on the basis of BC thickness. The optimal medium compositions for BC production were glucose 7%, soytone 12%, $K_2HPO_4$ 0.2%, $NaH_2PO_4{\cdot}_2H_2O$ 0.2%, lactic acid 0.05% and ethanol 0.3%, respectively. The strain F15 was able to produce BC at $26^{\circ}C-36^{\circ}C$ with a maximum at $32^{\circ}C$. BC production occurred at pH 4.5-8 with a maximum at pH 6.5. Under these conditions, a maximum BC thickness of 12.15 mm was achieved after 9 days of cultivation; this value was about 2.3-fold higher than the thickness in basic medium. Scanning electron micrographs showed that BC from the optimal medium was more compact than plant cellulose and was reticulated structure consisting of ultrafine cellulose fibrils. BC from the optimal medium was found to be of cellulose type I, the same as typical native cellulose.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.254-264
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• 2010

To obtain an efficient natural lignocellulolytic complex enzyme, we screened an efficient lignocellulose-degrading composite microbial system (XDC-2) from composted agricultural and animal wastes amended soil following a long-term directed acclimation. Not only could the XDC-2 degrade natural lignocelluloses, but it could also secrete extracellular xylanase efficiently in liquid culture under static conditions at room temperature. The XDC-2 degraded rice straw by 60.3% after fermentation for 15 days. Hemicelluloses were decomposed effectively, whereas the extracellular xylanase activity was dominant with an activity of 8.357 U/ml on day 6 of the fermentation period. The extracellular crude enzyme noticeably hydrolyzed natural lignocelluloses. The optimum temperature and pH for the xylanase activity were $40^{\circ}C$ and 6.0. However, the xylanase was activated in a wide pH range of 3.0-10.0, and retained more than 80% of its activity at $25-35^{\circ}C$ and pH 5.0-8.0 after three days of incubation in liquid culture under static conditions. PCR-DGGE analysis of successive subcultures indicated that the XDC-2 was structurally stable over long-term restricted and directed cultivation. Analysis of the 168 rRNA gene clone library showed that the XDC-2 was mainly composed of mesophilic bacteria related to the genera Clostridium, Bacteroides, Alcaligenes, Pseudomonas, etc. Our results offer a new approach to exploring efficient lignocellulolytic enzymes by constructing a high-performance composite microbial system with synergistic complex enzymes.

• KSBB Journal
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• 제22권2호
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• pp.91-96
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• 2007

본 연구에서는 음식폐기물 효소당화액을 BC생산 배지원으로 이용하여, flask정치배양과 50 L로 규모확대한 공기순환배양기에서 BC생산성을 검토하고, 생산된 BC의 제반물성을 조사하였다. 전단력을 낮추기 위해 당화액배지에 agar를 첨가하여 10 L, 50 L 공기순환배양기에서 배양한 결과, 50 L 규모로 scale-up한 반응기에서 5.64 g/L로 10 L 공기순환배양기 (5.84 g/L)에서와 동등한 BC 농도가 얻어져 BC 대량생산에 효과적인 배양방법임이 입증되었다. 50 L 규모로 확대된 공기순환배양기를 이용하는 본 배양 방법은 BC의 저비용 대량생산을 위한 효율적인 생산 방법 중 하나가 되리라 사료된다. 또한, 당화액을 배지로 하여 공기순환 방법으로 제조한 BC의 물성을 정치배양 방법으로 제조한 BC의 물성과 비교 검토한 결과, 공기순환법으로 제조하였을 때 중합도 및 역학적 성질이 약간 저하하였으나 결정성은 비슷하였으며, 배양기 용량의 대소에 따른 물성의 변화는 거의 없었다.