Enzymatic Production of High Molecular Weight Chitooligosaccharides Using Recombinant Chitosanase from Bacillus thuringiensis BMB171

( Lixin Kang ),( Sijing Jiang ),( Lixin Ma ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 한국미생물·생명공학회지 Vol.46 No.1

The chitosanase gene (btbchito) of Bacillus thuringiensis BMB171 was cloned and heterologously expressed in the yeast Pichia pastoris. After purification, about 300 mg of recombinant chitosanase was obtained from the 1-1 culture medium with a specific activity of 240 units/mg. Results determined by the combined use of thin layer chromatography (TLC) and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) showed that the chitooligosaccharides (COSs) obtained by chitosan (N-deacetylated by 70%, 80%, and 90%) hydrolysis by rBTBCHITO were comprised of oligomers, with degrees of polymerization (DP) mainly ranging from trimers to heptamers; high molecular weight chitopentaose, chitohexaose, and chitoheptaose were also produced. Hydrolysis products was also deduced using MS since the COSs (n) are complex oligosaccharides with various acetyl groups from one to two, so the non-acetyl COSs (GlcN)n and COSs with more acetyls (> 2) were not detected. The employment of this method in the production of high molecular weight COSs may be useful for various industrial and biological applications, and the activity of chitosanase has great significance in research and other applications.

Enzymatic Production of High Molecular Weight Chitooligosaccharides Using Recombinant Chitosanase from Bacillus thuringiensis BMB171

Kang, Lixin,Jiang, Sijing,Ma, Lixin The Korean Society for Microbiology and Biotechnol 2018 한국미생물·생명공학회지 Vol.46 No.1

The chitosanase gene (btbchito) of Bacillus thuringiensis BMB171 was cloned and heterologously expressed in the yeast Pichia pastoris. After purification, about 300 mg of recombinant chitosanase was obtained from the 1-1 culture medium with a specific activity of 240 units/mg. Results determined by the combined use of thin layer chromatography (TLC) and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) showed that the chitooligosaccharides (COSs) obtained by chitosan (N-deacetylated by 70%, 80%, and 90%) hydrolysis by rBTBCHITO were comprised of oligomers, with degrees of polymerization (DP) mainly ranging from trimers to heptamers; high molecular weight chitopentaose, chitohexaose, and chitoheptaose were also produced. Hydrolysis products was also deduced using MS since the COSs (n) are complex oligosaccharides with various acetyl groups from one to two, so the non-acetyl COSs (GlcN)n and COSs with more acetyls (> 2) were not detected. The employment of this method in the production of high molecular weight COSs may be useful for various industrial and biological applications, and the activity of chitosanase has great significance in research and other applications.

Residual Defect Prediction using Multiple Technologies

WanJiang Han,LiXin Jiang,TianBo Lu,XiaoYan Zhang 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.8

Finding defects in a software system is not easy. Effective detection of software defects is an important activity of software development process. In this paper, we propose an approach to predict residual defects, which applies machine learning algorithms (classifiers) and defect distribution model. This approach includes two steps. Firstly, use machine learning Algorithms and Association Rules to get defect classification table, then confirm the defect distribution trend referring to several distribution models. Experiment results on a GUI project show that the approach can effectively improve the accuracy of defect prediction and be used for test planning and implementation.

Comparison of Machine Learning Algorithms for Software Project Time Prediction

WanJiang Han,LiXin Jiang,TianBo Lu,XiaoYan Zhang 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.9

Software Project Management (SPM) is one of the primary factors to software success or failure. Prediction of software development time is the key task for the effective SPM. The accuracy and reliability of prediction mechanisms is also important. In this paper, we compare different machine learning techniques in order to accurately predict the software time. Finally, by comparing the accuracy of different techniques, it has been concluded that Gaussian process algorithm has highest prediction accuracy among other techniques studied. Experimental results show this prediction approach is more effective.

BRAF-Activated Long Noncoding RNA Modulates Papillary Thyroid Carcinoma Cell Proliferation through Regulating Thyroid Stimulating Hormone Receptor

Haitao Zheng,Meng Wang,Lixin Jiang,Haidi Chu,Jinchen Hu,Jinyao Ning,Baoyuan Li,Dong Wang,Jie Xu 대한암학회 2016 Cancer Research and Treatment Vol.48 No.2

Purpose The importance of long noncoding RNAs (lncRNAs) in tumorigenesis has recently been demonstrated. However, the role of lncRNAs in development of thyroid cancer remains largely unknown. Materials and Methods Using quantitative reverse transcription polymerase chain reaction, expression of three lncRNAs, including BRAF-activated long noncoding RNA (BANCR), papillary thyroid cancer susceptibility candidate 3 (PTCSC3), and noncoding RNA associated with mitogen-activated protein kinase pathway and growth arrest (NAMA), was investigated in the current study. Results Of the three lncRNAs (BANCR, PTCSC3, and NAMA), expression of BANCR was significantly up-regulated while PTCSC3 and NAMA were significantly down-regulated in papillary thyroid carcinoma (PTC) compared to that in normal tissue. BANCR-knockdown in a PTC-derived cell line (IHH-4) resulted in significant suppression of thyroid stimulating hormone receptor (TSHR). BANCR-knockdown also led to inhibition of cell growth and cell cycle arrest at G0/G1 phase through down-regulation of cyclin D1. In addition, BANCR was enriched by polycomb enhancer of zeste homolog 2 (EZH2), and silencing BANCR led to decreased chromatin recruitment of EZH2, which resulted significantly reduced expression of TSHR. Conclusion These findings indicate that BANCR may contribute to the tumorigenesis of PTC through regulation of cyclin D1 and TSHR.

Thermodynamics stability, electronic structures and spectroscopic properties of defects and Ce3+ ions in Y2O3

Wang Yan,Wen Jun,Zheng Jiangyun,Deng Zhifeng,Zhou Yueyu,Jiang Guisheng,Xia Qiangsheng,He Enjie,Ning Lixin 한국물리학회 2021 Current Applied Physics Vol.26 No.-

Thermodynamic properties, electronic structures and spectroscopic properties of defects and Ce3+ in Y2O3 are studied by using the hybrid density functional theory associated with multi-reference configuration interaction ab-initio calculations. Thermodynamic transition energy levels of the easily generated oxygen vacancies in the host are analyzed according to HSE06-calculated formation energies, which may be conducive to interpretations of the persistent luminescence (PersL) of Y2O3-based phosphors. Besides, the locations of impurity states (caused by VO and Ce3+) in energy bands are obtained from derived density of states. Moreover, energies and oscillator strengths of 4f1 → 5d1 5 transitions of Ce3+ ions (at Y1 and Y2 sites) calculated from the CASSCF/CASPT2/ RASSI SO method agree reasonably well with experimental excitation spectra of Y2O3: Ce3+ phosphors, achieving the assignment of excitation spectra. The presented calculations can be applied to identify luminescent centers in Ce3+-doped phosphors and reveals possible native defects and their roles in the PersL of phosphors.

Enhanced Strength-Ductility Synergy in Mg-0.5 wt%Ce Alloy by hot Extrusion

Hui Yu,Yu Liu,Ya Liu,Dongliang Wang,Yuling Xu,Binan Jiang,Weili Cheng,Lixin Huang,Weineng Tang,Wei Yu 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.7

The microstructure and mechanical properties of micro-alloyed Mg-0.5 wt%Ce alloys are investigated systemically in this study. It shows that Mg-Ce binary system is very sensitive to extrusion temperature. On the one hand, the high tensile yield strength (TYS) of 343 MPa was obtained by extrusion at 250 °C mainly due to the combined effects of profuse nano-precipitation phase, grain refinement, texture strengthening and high-density dislocation; On the other hand, the excellent elongation of 30% was acquired by extrusion at 300 °C resulting from the elimination of dislocations as well as the modification of texture.

Silicate Ions Derived from Calcium Silicate Extract Decelerate Ang II-Induced Cardiac Remodeling

Li Xin,Zhang Yanxin,Jin Qishu,Song Qiaoyu,Fan Chen,Jiao Yiren,Yang Chen,Chang Jiang,Dong Zhihong,Que Yumei 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.5

BACKGROUND: Pathological cardiac hypertrophy is one of the main activators of heart failure. Currently, no drug can completely reverse or inhibit the development of pathological cardiac hypertrophy. To this end, we proposed a silicate ion therapy based on extract derived from calcium silicate (CS) bioceramics for the treatment of angiotensin II (Ang II) induced cardiac hypertrophy. METHODS: In this study, the Ang II induced cardiac hypertrophy mouse model was established, and the silicate ion extract was injected to mice intravenously. The cardiac function was evaluated by using a high-resolution Vevo 3100 small animal ultrasound imaging system. Wheat germ Agglutinin, Fluo4-AM staining and immunofluorescent staining was conducted to assess the cardiac hypertrophy, intracellular calcium and angiogenesis of heart tissue, respectively. RESULTS: The in vitro results showed that silicate ions could inhibit the cell size of cardiomyocytes, reduce cardiac hypertrophic gene expression, including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and b-myosin heavy chain (b-MHC), decrease the content of intracellular calcium induced by Ang II. In vivo experiments in mice confirmed that intravenous injection of silicate ions could remarkably inhibit the cardiac hypertrophy and promote the formation of capillaries, further alleviating Ang II-induced cardiac function disorder. CONCLUSION: This study demonstrated that the released silicate ions from CS possessed potential value as a novel therapeutic strategy of pathological cardiac hypertrophy, which provided a new insight for clinical trials.