Influence of Controlled- and Uncontrolled-pH Operations on Recombinant Phenylalanine Ammonia Lyase Production in Escherichia coli

Jian Dong Cui,Gui Xia Zhao,Ya Nan Zhang,Shi Ru Jia 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.4

Effects of controlled- and uncontrolled-pH operations on phenylalanine ammonia lyase (PAL) production by a recombinant Escherichia coli strain were investigated at uncontrolled-pH (pHUC) and controlled-pH (pHC) of 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5 in bioreactor systems. The results showed that the recombinant PAL activity was improved significantly by controlled pH strategy. Among the pHC operations, the highest PAL activities were obtained under pHC 7.5 strategy where cell mass (OD600 ㎚) and PAL activity was 1.3 and 1.8 fold higher than those of pHUC, respectively. The maximum PAL activity reached 123 U/g. The pHC 7.5 strategy made recombinant plasmid more stable and therefore allowed easier expression of PAL recombinant plasmid, which increased PAL production. It was indicated that the new approach (controlled-pH strategy) obtained in this work possessed a high potential for the industrial production of PAL, especially in the biosynthesis of Lphenylalanine.

Isolation and Preliminary Identification of a Novel Microorganism Producing Aspartame from Soil Samples

Jian Dong Cui,Ya Nan Zhang,Gui Xia Zhao,Shi Ru Jia,Guo Qun Zhao,Si Zhang,Jun Lu 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.2

To develop a new method for producing aspartame (APM), a simple and efficient strategy for the isolation of certain microorganisms producing APM from soil samples was designed. A newly strain with secreting certain specific dipeptidase to directly synthesize APM from the substrates of L-aspartic acid (L-Asp) and Lphenylalanine methyl ester (L-PM) without protection for amino acid side chains was screened from soil samples. APM concentration in reaction mixture was quantified by high performance liquid chromatography (HPLC), yield reached 0.015 g/L. Examination of the general morphological characteristics and data from the sequence analysis of the rDNA-ITS gene led to identification of the isolate as a strain of fungal endophyte spp. The newly isolated strain had a high potential for application in industrial processes for APM production. In particular, this new method was low cost for synthesis of APM during the reaction due to avoiding protection for amino acid side chains and optical resolution of the mixtures. As we known it, this is first report that a newly strain with a high potential for selective synthesis of the APM was isolated from soil.

Optimization of Medium on Exopolysaccharides Production in Submerged Culture of Cordyceps militaris

Jian-Dong Cui,Shi-Ru Jia 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.6

Statistical experimental design strategy (SES) was applied to optimize the medium for the exopolysaccharides (EPS) production of Cordyceps militaris by submerged culture in shaker flask. A significant influence of the glucose and peptone on the EPS production was first evaluated by using a Plackett-Buman design. Then,steepest ascent method was employed to approach the experimental design space. Last, these factors were further optimized using central composite design (CCD) and response surface methodology (RSM). A quadratic model was found to fit the EPS production. The optimum values of the tested variables for the production of EPS were 48.67 g/L glucose, 12.56 g/L peptone, 1 g/L KH2PO4, 10 g/L yeast extract, and 0.5 g/L MgSO4·7H2O. Under optimization of culture conditions, the EPS production was enhanced from 0.78 to 1.96 g/L. In comparison with that of original culture conditions, 2.5 fold increase was obtained.

Kalman Filter-based Wind Speed Estimation for Wind Turbine Control

Dong-Ran Song,Mi Dong,Jian Yang,주영훈 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.3

To improve power production and reduce loads on turbine components, exact wind speed information isrequired in modern wind turbine controllers. However, the wind speed measured on the nacelle is imprecise becauseof its drawbacks of single point measurement and non-immunity to disturbances. To solve this problem, the EWS(Effective Wind Speed) estimator has been proposed as an alternative. According to the literatures, there are twokinds of EWS estimator, that is, the KF-based estimator and the EKF-based one. Where, the former is applied toestimate the aerodynamic torque, then the EWS is numerically calculated; and the latter directly estimate the EWS. Since the estimate EWS significantly affect the controller’s effectiveness, their performance needs to be clarified. To fully investigate the two estimators, there is a need to evaluate their performance on an even platform. In thispaper, we present comparative studies on these two methods. Their advantages and drawbacks are investigatedon the commercial turbine design software-bladed and compared through detailed simulation results. Finally, wedemonstrate some simulation results and differences between the KF-based estimator and the EKF-based one.

A new recombined porcine reproductive and respiratory syndrome virus virulent strain in China

Jian-guo Dong,Lin-yang Yu,Pei-pei Wang,Le-yi Zhang,Yan-ling Liu,Peng-shuai Liang,Chang-xu Song 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.1

Porcine reproductive and respiratory syndrome (PRRS) is one of the most important swine diseases worldwide. In the present study, a new virulent strain of PRRS virus (PRRSV), GDsg, was isolated in Guangdong province, China, and caused high fever, high morbidity, and high mortality in sows and piglets. The genome of this new strain was 15,413 nucleotides (nt) long, and comparative analysis revealed that GDsg shared 82.4% to 94% identity with type 2 PRRSV strains, but only 61.5% identity with type 1 PRRSV Lelystad virus strain. Phylogenetic analysis indicated that type 2 PRRSV isolates include five subgenotypes (I, II, III, IV, and V), which are represented by NADC30, VR-2332, GM2, CH-1a, and HuN4, respectively. Moreover, GDsg belongs to a newly emerging type 2 PRRSV subgenotype III. More interestingly, the newly isolated GDsg strain has multiple discontinuous nt deletions, 131 (19 + 18 + 94) at position 1404–1540 and a 107 nt insertion in the NSP2 region. Most importantly, the GDsg strain was identified as a virus recombined between low pathogenic field strain QYYZ and vaccine strain JXA1-P80. In conclusion, a new independent subgenotype and recombinant PRRSV strain has emerged in China and could be a new threat to the swine industry of China.

The Subjective Reflection and Artificial Intelligence Imagination of Sci-Fi Movies in the Post-Human Era

Jian-Dong, Cui,Seung-keun Song 한국콘텐츠학회 2021 한국콘텐츠학회 ICCC 논문집 Vol.2021 No.12

With the rapid development of disruptive technological achievements such as biotechnology, artificial intelligence, simulation technology, and genetic engineering, it has approached and even threatened the boundary and pattern of human existence, and is deeply challenging the subjectivity of natural persons. With the development of technology and virtual technology, the hybrid of organisms and machines (agents)-Cyborg (cyborg) is gradually consistent with humans both physically and consciously. This phenomenon has caused people to reflect on human subjectivity. The concretized representation of “cyborg”, artificial intelligence, and virtual space-time in post-human theories in science fiction movies involves the development of human form, social structure, and the future world. It shows how humans coexist with other life forms and helps We think about the living conditions of people and the relationship between people and the world in the “post-human” era.

Monoterpene esters and aporphine alkaloids from Illigera aromatica with inhibitory effects against cholinesterase and NO production in LPS-stimulated RAW264.7 macrophages

Jian-Wei Dong,Le Cai,Xue-Jiao Li,Jia-Peng Wang,Rui-Feng Mei,Zhong-Tao Ding 대한약학회 2017 Archives of Pharmacal Research Vol.40 No.12

Three new monoterpene phenylpropionic acidesters, illigerates A–C (1–3), and one new aporphinealkaloid, illigeranine (4), as well as four known ones,actinodaphnine (5), nordicentrine (6), 8-hydroxy carvacrol(7), and 3-hydroxy-a,4-dimethyl styrene (8), were isolatedfrom the tubers of Illigera aromatica. The structures of 1–4were identified by HRESIMS, 1D and 2D NMR, andelectronic circular dichroism spectra. Compound 1 potentlyinhibited NO production in LPS-stimulated RAW264.7cells with an IC50 value of 18.71 ± 0.85 lM; compound 1,3, and 4 showed moderate butyrylcholinesterase inhibitoryactivities with the IC50 values of 46.86 ± 0.65,53.51 ± 0.71, and 31.62 ± 1.15 lM, respectively. Compound4 showed weak AChE inhibitory activity with anIC50 value of 81.69 ± 2.07 lM, and compounds 5 and 6possessed moderate AChE inhibitory activities with theIC50 values of 47.74 ± 1.66 and 40.28 ± 2.73 lM,respectively. This paper provides a chemical structure andbioactive foundation for using I. aromatica as an herbalmedicine.

SYNTHESIS OF YTTRIA-STABILIZED CUBIC ZIRCONIA NANOCRYSTALS BY ULTRASONIC–MICROWAVE ROUTE

JIAN-DONG WANG,CHONG-XIAO LUO,YI LU,GUANG-MING LI,JIN-KU LIU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2010 NANO Vol.5 No.5

The yttria-stabilized zirconia (YSZ) nanocrystals with uniform size, high purity, and high degree of crystallinity, were prepared by ultrasonic–microwave-assisted method. The structure, optical properties and morphologies of YSZ nanocrystals were characterized by X-ray powder diffraction (XRD), Raman spectroscopy, UV–vis absorption, scanning electron microscope (SEM) and transmission electron microscopy (TEM). The SEM and TEM images of the YSZ nanocrystals indicate that the product is a mono-dispersion structure with an average particle size of about 25 nm.

Enhanced Activity of Phenylalanine Ammonia Lyase in Permeabilised Recombinant E. coli by Response Surface Method

Jian-dong Cui,Yan Li,Shi Ru Jia 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.2

To improve phenylalanine ammonia lyase (E.C.4.3.1.5-PAL) activity in recombinant Escherichia coli, Some approaches for improving phenylalanine ammonia lyase (PAL) activity in recombinant E. coli were developed following preliminary studies by means of response surface method. The results shown that permeabilization with combination of Triton X-100, cetyl trimethyl ammonium bromide (CTAB), and acetone enriched cellular recombinant PAL activity significantly, which improved over 10-fold as compared with the control (untreat cell), as high as 181.37 U/g. The optimum values for the tested variables were Triton X-100 0.108 g/ℓ, CTAB 0.15 g/ℓ, and acetone 45.2%(v/v). Furthermore, a second-order model equation was suggested and then validated experimentally. It was indicated that addition of surfactants and organic solvents made the cells more permeable and therefore allowed easier access of the substrate to the enzyme and excretion of the product, which increased the rate of transport of L-phenylalanine and trans-cinnamic acids. These improved methods of PAL activity enrichment could serve as a rich enzyme source, especially in the biosynthesis of L-phenylalanine.

중국인 한국어 학습자의 ‘체언+용언’ 형 연어 오류 양상에 대한 연구

Jian-Dong Lin,김은호 한국현대언어학회 2019 언어연구 Vol.34 No.4

Systematic and in-depth analyses of Chinese Korean language learners' lexical errors in general and of collocation errors in particular are relatively rare. This study presents empirical data verifying the informal observations and theoretic assertions that Chinese learners of Korean language produce 'unnatural' word combinations. In this paper the authors used a more comprehensive error taxonomy based on previous studies to analyse Chinese learners’ use of Korean collocations. The analysis revealed that the identified sources of errors were mainly from L2 intrinsic difficulty rather than the first language (L1) transfer. The findings from the Chinese learners’ errors in the use of Korean collocations have implications for L2 vocabulary teaching and learning, which should be of interest to wider Korean as a Second Language (KSL)/Korean as a Foreign Language (KFL) contexts. Systematic and in-depth analyses of Chinese Korean language learners' lexical errors in general and of collocation errors in particular are relatively rare. This study presents empirical data verifying the theoretic assertions that Chinese learners of Korean language produce 'unnatural' word combinations. In this paper the authors used a more comprehensive error taxonomy based on previous studies to analyse Chinese learners’ use of Korean collocations. The analysis revealed that the identified sources of errors were mainly from L2 intrinsic difficulty rather than the first language (L1) transfer. The findings from the Chinese learners’ errors in the use of Korean collocations have implications for L2 vocabulary teaching and learning, which should be of interest to wider Korean as a Second Language (KSL)/Korean as a Foreign Language (KFL) contexts.