• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.5
• /
• pp.834-841
• /
• 1997

A lactic acid bacteria which showed antimicrobial activity was isolated from dairy products and identified as Lactobacillus sp. according to the morphological, physiological and biochemical properties, which was named Lactobacillus sp. SH 7311. The bacteriocin of Lactobacillus sp. GM 7311 showed a broad range of inhibitory spectrum against some gram positive and negative bacteria. Especially, Proteus mirabilis was highly sensitive to bacteriocin and used as indicator strain for further investigation. The optimal condition for the production of bacteriocin was showed on MRS broth at $37^{\circ}C$ and pM 6.0. Bacteriocin production of this strain cultured under optimal condition was increased late logarithmic phase to early stationary phase. This bacteriocin was fully active at the pH range $2.0\~5.0$, also was stable at $100^{\circ}C$ for 60 min. at pH 5.0, But about $40\%$ of bacteriocin activity was diminished by the treatment of acetone, ethanol, iso-butanol and ethyl ether during 2 hours at $4^{\circ}C$.

• Korean Journal of Agricultural Science
• /
• v.47 no.4
• /
• pp.815-827
• /
• 2020

The epidermal growth factor (EGF) transgenic soybean was developed and biosynthesis of human epidermal growth factor (hEGF) in soybean seeds was confirmed. Also, EGF transgenic soybean were found to contain a herbicide resistance selectable marker by introduction of phosphinothricin acetyltransferase (PAT) gene from the Streptomyces hygroscopicus. For biosafety assessment, the EGF transgenic soybean expressing the EGF biosynthesis gene EGF and herbicide resistant gene PAT was tested to determine effects on survival of Cyprinus carpio, commonly used as a model organism in ecotoxicological studies. C. carpio was fed 100% ground soybean suspension, EGF soybean or non-genetically modified (GM) counterpart soybean (Gwangan). Gene expression of EGF soybean was confirmed by PCR and ELISA to have EGF/PAT. Feeding test showed that no significant differences in cumulative immobility or abnormal response between C. carpio samples fed on EGF soybean and non-GM counterpart soybean. The 48 h-EC50 values of the EGF and non-GM soybean were 1,688 mg·L-1 (95% confidence limits: 1,585 - 1,798 mg·L-1) and 1,575 mg·L-1 (95% confidence limits: 1,433 - 1,731 mg·L-1), respectively. The soybean NOEC (no observed effect concentration) value for C. carpio was suggested to be 625 mg·L-1. We concluded that there was no significant difference in toxicity for non-target organisms (C. carpio) between the EGF soybean and non-GM counterparts.

• Proceedings of the KIEE Conference
• /
• 2001.11c
• /
• pp.348-351
• /
• 2001

In this paper, the Gm-C filter for low voltage and low power applications using a fully-differential transconductor is presented. The designed transconductor using the series composite transistors and the low voltage composite transistors has wide input range at low supply voltage. A negative resistor load (NRL) technology for high DC gain of the transconductor is employed with a common mode feedback(CMFB). As a design example, the third-order Elliptic lowpass filter is designed. The designed filter is simulated and examined by HSPICE using TSMC $0.35{\mu}m$ CMOS n-well parameters. The simulation results show 138kHz cutoff frequency and 11.05mW power dissipation with a 3.3V supply voltage.

• Proceedings of the IEEK Conference
• /
• 2000.11b
• /
• pp.257-260
• /
• 2000

In this paper, a Gm-C filter for low voltage and low power applications using a fully-differential transconductor is presented. The designed transconductor using the series composite transistors and the low voltage composite transistors has wide input range at low supply voltage. A negative resistor load (NRL) technology for high DC gain of the transconductor is employed with a common mode feedback (CMFB). As a design example, the third-order Elliptic lowpass filter is designed. The designed filter is simulated and examined by HSPICE using 0.25${\mu}{\textrm}{m}$ CMOS n-well parameters. The simulation results show 105MHz cutoff frequency and 2.4㎽ power dissipation with a 2.5V supply voltage.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1927-1928
• /
• 2008

가변 이득 및 차단주파수 특성을 가지는 5차 CMOS Gm-C 필터를 설계하였다. 설계된 필터는 CMOS 차동 트랜스컨덕터들로 구성하였으며 트랜스컨덕터들은 각각 전압 조정에 의하여 트랜스컨덕턴스 값이 변환되도록 설계하였다. 가변 차단주파수 특성은 외부잡음으로 발생할 수 있는 필터 차단주파수의 변형을 보상할 수 있고 한 개의 필터로써 다중대역 수신 단에 적용할 수 있도록 하고자 하였다. HSPICE 시뮬레이션 결과, 1.5MHz$\sim$3.5MHz의 차단주파수의 조정이 가능하였고 이득은 -2.8dB$\sim$2.6dB으로의 조정이 가능하였다.

• ETRI Journal
• /
• v.28 no.2
• /
• pp.175-181
• /
• 2006

A new CMOS voltage-controlled fully-differential transconductor is presented. The basic structure of the proposed transconductor is based on a four-MOS transistor cell operating in the triode or saturation region. It achieves a high linearity range of ${\pm}\;1\;V$ at a 1.5 V supply voltage. The proposed transconductor is used to realize a new fully-differential Gm-C low-pass filter with a minimum number of transconductors and grounded capacitors. PSpice simulation results for the transconductor circuit and its filter application indicating the linearity range and verifying the analytical results using $0.35\;{\mu}m$ technology are also given.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.10a
• /
• pp.275-277
• /
• 2014

본 논문에서는 다양한 주파수 튜닝이 가능한 직접변환방식을 이용한 Gm-C 능동필터 회로를 설계하였다. 설계된 필터는 집적회로를 튜닝하여 요구되는 기준주파수 및 대역폭과 이득을 만족시킬 수 있다. 필터에 사용된 OTA회로는 전달 트랜스컨덕턴스 값을 외부전압으로 제어할 수 있도록 설계하여 다양한 주파수대역에서 사용할 수 있다는 장점을 가진다. 설계된 필터는 ripple 전압을 최소화 하고 이득 값을 높일 수 있는 Elliptic 필터를 사용하였다. 집적화를 위하여 수동필터를 능동필터로 변환할 수 Gyrator 방식을 이용하였다. HSPICE 시뮬레이션 결과, 외부전압을 1.0V~1.9V까지 변화를 주었을 때 1.4MHz ~ 2.8MHz의 차단주파수의 조정이 가능하였고 소비전력은 4.5mW~20mW임을 측정하였다.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.206-209
• /
• 2001

Recombinant human GM -CSF was expressed and secreted from transgenic rice cell suspension cultures in its biologically active form. This was accomplished by transforming rice callus tissues with an expression vector, pMYN44. containing the hGM -CSF cDNA. Regulated expression and secretion of hGM -CSF from this vector achieved using the promoter, signal peptide, and terminator from a rice alfa-amylase gene Amy3D. The Amy3D gene is expressed in response to sugar deprivation. The recombinant hGM -CSF was expressed from the transgenic rice cell culture on the sugar-free medium as a yield of about 110 mg/L in the culture filtrate, which was determined by ELISA. Biological activity of hGM-CSF was confirmed by measuring the proliferation of the hGM -CSF dependent TF -1 cells.(This work was supported by a grant from the NRL program of the Korean Ministry of Science and Technology. Shin, Y.- J.. Lee. J.-H and Kwon, T.-H. have been supported by BK21 program from the Korean Ministry of Education)

• Journal of Plant Biotechnology
• /
• v.39 no.3
• /
• pp.175-181
• /
• 2012

Drought and high salinity stresses often imposes adverse effects on crop yield. MYB transcription factors have been shown to be an important regulator in defense responses to these environmental stresses. In this study, we have cloned and characterized a soybean gene GmMYB184 (Glycine max MYB transcription factor 184). Deduced amino acid sequences of GmMYB184 show highest homology with that from Vitis vinifera legume plant (75%). Different expression patterns of GmMYB184 mRNA were observed subjected to drought, cold, high salinity stress and abscisic acid treatment, suggesting its role in the signaling events in the osmotic stress-related defense response. Subcellular localization studies demonstrated that the GFP-GmMYB184 fusion protein was localized in the nucleus. Using the yeast assay system, the C-terminal region of GmMYB184 was found to be essential for the transactivation activity. These results indicate that the GmMYB184 may play a role in abiotic stress tolerance in plant.

• Microbiology and Biotechnology Letters
• /
• v.21 no.5
• /
• pp.494-503
• /
• 1993

A fungal strain was isolated as a pullulan-producer from plant leaves and identified as Aureobasidium pullulan GM21. With A. pullulans GM21, culture conditions were optimized for the pullulan production and the changes of the molecular weight of pullulan produced were investigated according to the culture conditions we obtained maximum conversion yield of pullulan about 58-60%(40.8-42.0g/l) from 7% sucrose at 25C, initial pH 7.5 by the batch cultivations either in Erlenmeyer flask or in jar fermentor.