Production and Characterization of Ethanol- and Protease-Tolerant and Xylooligosaccharides-Producing Endoxylanase from Humicola sp Ly01

( Jun Pei Zhou ),( Qian Wu ),( Rui Zhang ),( Yu Ying Yang ),( Xiang Hua Tang ),( Jun Jun Li ),( Jun Mei Ding ),( Yan Yan Dong ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.6

This paper reports the production and characterization of crude xylanase from the newly isolated Humicola sp. Ly01. The highest (41.8 U/ml) production of the crude xylanase was obtained under the optimized conditions (w/v): 0.5% wheat bran, 0.2% KH2PO4, and 0.5% peptone; initial pH 7.0; incubation time 72 h; 30℃; and 150 rpm. A considerable amount of the crude xylanase was induced using hulless barley bran or soybean meal as the carbon source, but a small amount of the enzyme was produced when supplementary urea was used as the nitrogen source to wheat bran. The crude xylanase showed apparent optimal cellulase-free xylanase activity at 60℃ and pH 6.0, more than 71.8% of the maximum xylanase activity in 3.0-30.0% (v/v) ethanol and more than 82.3% of the initial xylanase activity after incubation in 3.0-30.0% (v/v) ethanol at 30℃ for 2 h. The crude xylanase was moderately resistant to both acid and neutral protease digestion, and released 7.9 and 10.9 μmol/ml reducing sugar from xylan in the simulated gastric and intestinal fluids, respectively. The xylooligosaccharides were the main products of the hydrolysis of xylan by the crude xylanase. These properties suggested the potential of the crude enzyme for being applied in the animal feed industry, xylooligosaccharides production, and high-alcohol conditions such as ethanol production and brewing.

Fuzzy Logic Based Temporal Error Concealment for H.264 Video

Pei-Jun Lee,Ming-Long Lin 한국전자통신연구원 2006 ETRI Journal Vol.28 No.5

In this paper, a new error concealment algorithm is proposed for the H.264 standard. The algorithm consists of two processes. The first process uses a fuzzy logic method to select the size type of lost blocks. The motion vector of a lost block is calculated from the current frame, if the motion vectors of the neighboring blocks surrounding the lost block are discontinuous. Otherwise, the size type of the lost block can be determined from the preceding frame. The second process is an error concealment algorithm via a proposed adapted multiplereference- frames selection for finding the lost motion vector. The adapted multiple-reference-frames selection is based on the motion estimation analysis of H.264 coding so that the number of searched frames can be reduced. Therefore the most accurate mode of the lost block can be determined with much less computation time in the selection of the lost motion vector. Experimental results show that the proposed algorithm achieves from 0.5 to 4.52 dB improvement when compared to the method in VM 9.0.

Survival and Performance of Two Cellulose-Degrading Microbial Systems Inoculated into Wheat Straw-Amended Soil

( Pei Pei Li ),( Dong Dong Zhang ),( Xiao Juan Wang ),( Xiao Fen Wang ),( Zong Jun Cui1 ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.1

A cellulose-degrading composite microbial system containing a mixture of microbes was previously shown to demonstrate a high straw-degrading capacity. To estimate its potential utilization as an inoculant to accelerate straw biodegradation after returning straw to the field, two cellulose-degrading composite microbial systems named ADS3 and WSD5 were inoculated into wheat straw-amended soil in the laboratory. The microbial survival of the inoculant was confirmed by a denaturing gradient gel electrophoresis (DGGE) analysis, whereas the enhancement of straw degradation in soil was assessed by measuring the mineralization of the soil organic matter and the soil cellulase activity. The results indicated that most of the DGGE bands from ADS3 were detected after inoculation into straw-amended autoclaved soil, yet only certain bands from ADS3 and WSD5 were detected after inoculation into straw-amended non-autoclaved soil during five weeks of incubation; some bands were detected during the first two weeks after inoculation, and then disappeared in later stages. Organic matter mineralization was significantly higher in the soil inoculants ADS3 and WSD5 than in the uninoculated controls during the first week, yet the enhanced degradation did not persist during the subsequent incubation. Similar to the increase in soil organic matter, the cellulase activity also increased during the first week in the ADS3 and WSD5 treatments, yet decreased during the remainder of the incubation period. Thus, it was concluded that, although the survival and performance of the two inoculants did not persist in the soil, a significant enhancement of degradation was present during the early stage of incubation.

Potential Antitumor Activity of SIM-89 in Non-Small Cell Lung Cancer Cells

Jun Pei,Baohui Han,Tianqing Chu,Minhua Shao,Jiajun Teng,Huifang Sha,Aiqing Gu,Rong Li,Jialin Qian,Weifeng Mao,Ying Li 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.3

Purpose: c-Met and its ligand, hepatocyte growth factor (HGF), play a critical role in oncogenesis and metastatic progression. The aim of this study was to identify inhibited enzymogram and to test the antitumor activity of SIM-89 (a c-Met receptor tyrosine kinaseinhibitor) in non-small cell lung cancer. Materials and Methods: Z’-LYTE kinase assay was employed to screen the kinase enzymogram, and mechanism of action (MOA) analysis was used to identify the inhibited kinases. Cell proliferation was then analyzed by CCK8 assay, and cell migration was determinedby transwell assay. The gene expression and the phosphorylation of c-Met were examined by realtime-PCR and western blotting, respectively. Finally, the secretion of HGF was detected by ELISA assay. Results: c-Met, activated protein kinase (AMPK), and tyrosine kinase A (TRKA) were inhibited by SIM-89 with the IC50 values of 297 nmol/L, 1.31 μmol/L, and 150.2 nmol/L, respectively. SIM-89 exerted adenosine triphosphate (ATP) competitive inhibition on c-Met. Moreover, the expressions of STAT1, JAK1, and c-Met in H460 cells were decreased by SIM-89 treatment, and c-Met phosphorylationwas suppressed in A549, H441, H1299, and B16F10 cells by the treatment. In addition, SIM-89 treatment significantly decreased the level of HGF, which accounted for the activation of c-Met receptor tyrosine kinase. Finally, we showed cell proliferationinhibition and cell migration suppression in H460 and H1299 cells after SIM-89 treatment. Conclusion: In conclusion, SIM-89 inhibits tumor cell proliferation, migration and HGF autocrine, suggesting it’s potential antitumoractivity.

Molecular and Biochemical Characterization of a Novel Intracellular Low-Temperature-Active Xylanase

( Jun Pei Zhou,),( Yan Yan Dong ),( Xiang Hua Tang ),( Jun Jun Li ),( Bo Xu ),( Qian Wu ),( Ya Jie Gao ),( Lu Pan ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.4

A 990 bp full-length gene (xynAHJ2) encoding a 329- residue polypeptide (XynAHJ2) with a calculated mass of 38.4 kDa was cloned from Bacillus sp. HJ2 harbored in a saline soil. XynAHJ2 showed no signal peptide, distinct amino acid stretches of glycoside hydrolase (GH) family 10 intracellular endoxylanases, and the highest amino acid sequence identity of 65.3% with the identified GH 10 intracellular mesophilic endoxylanase iM-KRICT PX1-Ps from Paenibacillus sp. HPL-001 (ACJ06666). The recombinant enzyme (rXynAHJ2) was expressed in Escherichia coli and displayed the typical characteristics of low-temperatureactive enzyme (exhibiting optimum activity at 35 o C, 62% at 20 o C, and 38% at 10 o C; thermolability at ≥45 o C). Compared with the reported GH 10 low-temperature-active endoxylanases, which are all extracellular, rXynAHJ2 showed low amino acid sequence identities (<45%), low homology (different phylogenetic cluster), and difference of structure (decreased amount of total accessible surface area and exposed nonpolar accessible surface area). Compared with the reported GH 10 intracellular endoxylanases, which are all mesophilic and thermophilic, rXynAHJ2 has decreased numbers of arginine residues and salt bridges, and showed resistance to Ni 2+ , Ca 2+ , or EDTA at 10 mM final concentration. The above mechanism of structural adaptation for low-temperature activity of intracellular endoxylanase rXynAHJ2 is different from that of GH 10 extracellular low-temperature-active endoxylanases. This is the first report of the molecular and biochemical characterizations of a novel intracellular low-temperatureactive xylanase.

Cloning, Heterologous Expression, and Characterization of Novel Protease- Resistant α-Galactosidase from New Sphingomonas Strain

( Jun Pei Zhou ),( Yan Yan Dong ),( Jun Jun Li ),( Rui Zhang ),( Xianghua Tang ),( Yuelin Mu ),( Bo Xu ),( Qian Wu ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.11

The α-galactosidase-coding gene agaAJB13 was cloned from Sphingomonas sp. JB13 showing 16S rDNA (1,343 bp) identities of ≤97.2% with other identified Sphingomonas strains. agaAJB13 (2,217 bp; 64.9% GC content) encodes a 738-residue polypeptide (AgaAJB13) with a calculated mass of 82.3 kDa. AgaAJB13 showed the highest identity of 61.4% with the putative glycosyl hydrolase family 36 α-galactosidase from Granulicella mallensis MP5ACTX8 (EFI56085). AgaAJB13 also showed <37% identities with reported protease-resistant or Sphingomonas α-galactosidases. A sequence analysis revealed different catalytic motifs between reported Sphingomonas α-galactosidases (KXD and RXXXD) and AgaAJB13 (KWD and SDXXDXXXR). Recombinant AgaAJB13 (rAgaAJB13) was expressed in Escherichia coli BL21 (DE3). The purified rAgaAJB13 was characterized using p-nitrophenyl-α-D-galactopyranoside as the substrate and showed an apparent optimum at pH 5.0 and 60oC and strong resistance to trypsin and proteinase K digestion. Compared with reported proteaseresistant α-galactosidases showing thermolability at 50oC or 60oC and specific activities of <71 U/mg with or without protease treatments, rAgaAJB13 exhibited a better thermal stability (half-life of >60 min at 60oC) and higher specific activities (225.0-256.5 U/mg). These sequence and enzymatic properties suggest AgaAJB13 is the first identified and characterized Sphingomonas α-galactosidase, and shows novel protease resistance with a potential value for basic research and industrial applications.

Biochemical Characterization of a GDSL-Motif Esterase from Bacillus sp. K91 with a New Putative Catalytic Mechanism

( Jun Mei Ding ),( Ting Ting Yu ),( Lian Ming Liang ),( Zhen Rong Xie ),( Yun Juan Yang ),( Jun Pei Zhou ),( Bo Xu ),( Jun Jun Li ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.11

The esterase gene Est8 from the thermophilic bacterium Bacillus sp. K91 was cloned and expressed in Escherichia coli. The monomeric enzyme exhibited a theoretical molecular mass of 24.5 kDa and an optimal activity around 50°C at pH 9.0. A model of Est8 was constructed using a hypothetical YxiM precursor structure (2O14_A) from Bacillus subtilis as template. The structure showed an α/β-hydrolase fold and indicated the presence of a typical catalytic triad consisting of Ser-11, Asp-182, and His-185, which were investigated by site directed replacements coupled with kinetic characterization. Asp-182 and His-185 residues were more critical than the Ser-11 residue in the catalytic activity of Est8. A comparison of the amino acid sequence showed that Est8 could be grouped into the GDSL family and further classified as an SGNH hydrolase. Est8 is a new member of the SGNH hydrolase subfamily and may employ a different catalytic mechanism.

클링커를 골재로 활용한 콘크리트의 특성에 관한 문헌연구

배준걸 ( Pei Jun Jie ),장정국 ( Jang Jeong Gook ) 한국구조물진단유지관리공학회 2020 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.24 No.2

클링커는 소성로에서 석회석과 점토 등이 소성, 화합되어 나오는 직경 3~26mm 정도 크기의 잔자갈 모양의 덩어리이다. 콘크리트 제조에 사용되는 천연 골재의 부족 문제를 해결하기 위하여 다양한 재료가 검토되고 있으며, 클링커는 후보 물질 중 하나로서 다수의 연구가 진행되고 있다. 문헌 조사 연구 결과에 의하면 천연 골재의 대체재로 클링커를 사용하면 클링커의 표면에서 일어나는 수화반응으로 인해 콘크리트의 압축강도가 향상될 수 있는 반면 굳지않은 콘크리트의 물성에는 부정적인 영향을 미칠 수도 있음을 알 수 있다. 본 연구에서는 클링커 골재를 활용한 기존의 연구들을 고찰하여 향후 클링커 골재 대체 기술의 전망을 제시하였다.

Phylogenetic Diversity of Bacteria in an Earth-Cave in Guizhou Province, Southwest of China

Zhou, Jun-Pei,Gu, Ying-Qi,Zou, Chang-Song,Mo, Ming-He The Microbiological Society of Korea 2007 The journal of microbiology Vol.45 No.2

The objective of this study was to analyze the phylogenetic composition of bacterial community in the soil of an earth-cave (Niu Cave) using a culture-independent molecular approach. 16S rRNA genes were amplified directly from soil DNA with universally conserved and Bacteria-specific rRNA gene primers and cloned. The clone library was screened by restriction fragment length polymorphism (RFLP), and representative rRNA gene sequences were determined. A total of 115 bacterial sequence types were found in 190 analyzed clones. Phylogenetic sequence analyses revealed novel 16S rRNA gene sequence types and a high diversity of putative bacterial community. Members of these bacteria included Proteobacteria (42.6%), Acidobacteria (18.6%), Planctomycetes (9.0 %), Chloroflexi (Green nonsulfur bacteria, 7.5%), Bacteroidetes (2.1%), Gemmatimonadetes (2.7%), Nitrospirae (8.0%), Actinobacteria (High G+C Gram-positive bacteria, 6.4%) and candidate divisions (including the OP3, GN08, and SBR1093, 3.2%). Thirty-five clones were affiliated with bacteria that were related to nitrogen, sulfur, iron or manganese cycles. The comparison of the present data with the data obtained previously from caves based on 16S rRNA gene analysis revealed similarities in the bacterial community components, especially in the high abundance of Proteobacteria and Acidobacteria. Furthermore, this study provided the novel evidence for presence of Gemmatimonadetes, Nitrosomonadales, Oceanospirillales, and Rubrobacterales in a karstic hypogean environment.

Land Use/Cover Change Detection with Change Vector Analysis(CVA) : Change Magnitude Threshold Determination

Shi, Pei Jun,Jin, Chen,Yang, He Chun 대한원격탐사학회 2000 International Symposium on Remote Sensing Vol.16 No.1

Change Vector Analysis (CVA) is a valuable approach for land use/cover change detection, in which how to determine change magnitude threshold and change direction reasonably is already becoming an obstacle for its utility far and wide. Therefore, a new method named Double-Windows Flexible Pace Searching is proposed in this paper aimed to determine change magnitude threshold reasonably and efficiently. As the result from the case study in Haidian District, Beijing , the accuracy rate of change detection is obtained about 87% which suggest Double-Windows Flexible Pace Searching method potential utility in Change Vector Analysis for land use/cover change detection.