Microwave-assisted Approach for the Rapid Enzymatic Digestion of Rapeseed Meal

Ju-Fang Li,Fang Wei,Lu-Lu Guo,Gang-You Yuan,Feng-Hong Huang,Mu-Lan Jiang,Yuan-Di Zhao,Xu-Yan Dong,Guang-Ming Li,Hong Chen 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.2

This study demonstrates the use of a new microwave-assisted approach for accelerating the enzymatic digestion of rapeseed meal. The effects of different microwave parameters, such as the time, temperature, and power level, on the degree of hydrolysis (DH) were investigated by using response surface methodology (RSM). The maximum predicted DH value (10.2%) was in good agreement with the value obtained experimentally using an alkaline protease, which was 12.57% under optimal conditions. In only 7 min, the microwave-assisted method achieved a DH value similar to that obtained by the conventional enzymatic digestion method (4 hr). Therefore,this new technique for rapid enzymatic digestion will improve the application of rapeseed meal in the preparation of protein hydrolysates for use in food and feed.

Enhanced Protein Production by Sorbitol Co-feeding with Methanol in Recombinant Pichia pastoris Strains

Li Chen,Ali Mohsin,Ju Chu,Ying-ping Zhuang,Yamei Liu,Mei-Jin Guo 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.6

Pichia pastoris strains carrying 1, 6, 12, and 18 copies of the porcine insulin precursor (PIP) gene, were employed to investigate the effects of sorbitol co-feeding with methanol on the physiology of the strains. Multicopy clones of the methylotrophic yeast were generated to vary the PIP gene dosage and recombinant proteins. Elevated gene dosage increased levels of the recombinant PIP protein when methanol served as the sole carbon and energy source i.e., an increase of 1.9% for a strain carrying 1 copy, 42.6% for a strain carrying 6 copies, 34.7% for a strain carrying 12 copies and 80.9% for a strain carrying 18 copies, respectively (using sorbitol co-feeding with methanol during the induction phase). However, it had no significant influence on a lower gene dosage strain (1 copy), but this approach affirmed enhancement in cell growth and PIP production for higher gene dosage strain (6, 12, and 18 copies) via using sorbitol co-feeding with methanol. Additionally, the co-feeding strategy could hold vital importance for recombinant protein production by a multi-copy P. pastoris system.

Gamma and X-ray irradiation as a phytosanitary treatment against various stages of Planococcus lilacinus (Hemiptera: Pseudococcidae)

Ma Chen,Liu Hui,Liu Bo,Zhao Ju-Peng,Zhao Qing-Ying,Song Zi-Jiao,Han Xin,Zhan Guo-Ping 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.4

The cacao mealybug, Planococcus lilacinus Cock, is an important quarantine pest. Infested commodity should be subject to appropriate phytosanitary treatment, while irradiation is recommended for the cacao mealybug. Radio-tolerance comparison tests were conducted on the crawler, nymphs, and adult females of P. lilacinus at the X-ray radiation doses of 40, 80, and 120 Gy, respectively. The results showed that irradiation had a strong effect on preventing of development and reproduction; the adult female stage was identified as the most tolerant. During the following dose–response tests, among young and late females X-ray-irradiation (20–100 Gy), the late females were most tolerant when preventing F 1 generation 2nd instars emergence was used as the evaluation criterion. Minimum absorbed dose and its 95 % fiducial limits to provide probit 9 efficacy at 95 % confidence level (100 % mortality/inhibition in an estimated population of 93,616 individuals) were 131.5 Gy (122.5, 142.6 Gy) and 144.4 Gy (132.7, 159.4 Gy), estimating from the probit analysis on dose-mortality data of 1–30 and 1–10-day-old neonates laid by late females, respectively. In the large-scale confirmatory tests, a total of estimating 97,384 late females of P. lilacinus rearing on the pumpkins fruits were irradiated with gamma-ray at the target dose of 135 or 145 Gy (measured doses 126.1–163.0 Gy), which resulted in no F 1 generation 2nd nymphs developing during a 6-week post-treatment period. The treatment efficacy calculated is 99.9969 % at the 95 % confidence level. Therefore, a minimum absorbed dose of 163.0 Gy is recommended for phytosanitary treatment of P. lilacinus in infested commodity.

Chromatographic Behavior of Proteins on Stationary Phase with Aminocarboxy Ligand

Li, Rong,Ju, Ming-Yang,Chen, Bin,Sun, Qing-Yuan,Chen, Guo-Liang,Shi, Mei,Wang, Xiao-Gang,Zheng, Jian-Bin Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

An aminocarboxy aspartic acid-bonded silica (Asp-Silica) stationary phase was synthesized using L-aspartic acid as ligand and silica gel as matrix. The standard protein mixtures were separated with prepared chromatographic column. The effects of solution pH, salt concentration and metal ion on the retention of proteins were examined, and also compared with traditional iminodiacetic acid-bonded silica (IDA-Silica) column. The results show that Asp-Silica column exhibited an excellent separation performance for proteins. The retention of proteins on Asp-Silica stationary phase was consistent with electrostatic characteristic of cation-exchange. The stationary phase displayed typical metal chelate property after fixing copper ion (II) on Asp-Silica. Under competitive eluting condition, protein mixtures were effectively isolated. Asp ligand showed better ion-exchange and metal chelating properties as compared with IDA ligand.

In Vivo Assessment of Neurodegeneration in Type C Niemann-Pick Disease by IDEAL-IQ

Ruo-Mi Guo,Qing-Ling Li,Zhong-Xing Luo,Wen Tang,Ju Jiao,Jin Wang,Zhuang Kang,Shao-Qiong Chen,Yong Zhang 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.1

Objective: To noninvasively assess the neurodegenerative changes in the brain of patients with Niemann-Pick type C (NPC) disease by measuring the lesion tissue with the iterative decomposition of water and fat with echo asymmetry and least square estimation-iron quantification (IDEAL-IQ). Materials and Methods: Routine brain MRI, IDEAL-IQ and 1H-proton magnetic resonance spectroscopy (1H-MRS, served as control) were performed on 12 patients with type C Niemann-Pick disease (4 males and 8 females; age range, 15−61 years; mean age, 36 years) and 20 healthy subjects (10 males and 10 females; age range, 20−65 years; mean age, 38 years). The regions with lesion and the normal appearing regions (NARs) of patients were measured and analyzed based on the fat/water signal intensity on IDEAL-IQ and the lipid peak on 1H-MRS. Results: Niemann-Pick type C patients showed a higher fat/water signal intensity ratio with IDEAL-IQ on T2 hyperintensity lesions and NARs (3.7−4.9%, p < 0.05 and 1.8−3.0%, p < 0.05, respectively), as compared to healthy controls (HCs) (1.2−2.3%). After treatment, the fat/water signal intensity ratio decreased (2.2−3.4%), but remained higher than in the HCs (p < 0.05). The results of the 1H-MRS measurements showed increased lipid peaks in the same lesion regions, and the micro-lipid storage disorder of NARs in NPC patients was detectable by IDEAL-IQ instead of 1H-MRS. Conclusion: The findings of this study suggested that IDEAL-IQ may be useful as a noninvasive and objective method in the evaluation of patients with NPC; additionally, IDEAL-IQ can be used to quantitatively measure the brain parenchymal adipose content and monitor patient follow-up after treatment of NPC.

SOLID STATE TEACTIONS IN THE $Co/Si_{1-X}Ge_X$ SYSTEM

Lin, Wen-Tai,Chen, Guo-Ju,Chang, C.Y. 한국재료학회 1995 Fabrication and Characterization of Advanced Mater Vol.2 No.e2

Thermal reactions of Co/S$i_{0.76}$ G$e_{0.24}$ and Co/S$i_{0.54}$ G$e_{0.46}$ systems are studied. Gr segreation appeared at temperatures above 20$0^{\circ}C$ even no cobalt silicides and/or cobalt germanosilicides were formed. At a temperature of 250-50$0^{\circ}C$ Co(S$i_{1-y}$ G$e_y$) was formed, in which the Ge concentation was deficient and inhomogeneous. Ge played a crucial role in retarding the interfacial reactions between Co and S$i_{1-x}$G$e_x$ layer. At temperatures above 45$0^{\circ}C$ the island structure was formed and the Ge concentration was enriched in the surface of the exposed S$i_{1-x}$ G$e_x$ layer. At temperatures above 53$0^{\circ}C$ nearly Ge-free CoS$i_2$was formed. An interposing Si layer between Co and the S$i_{1-x}$G$e_x$ layer can alleviate the strain relaxation of the S$i_{1-x}$G$e_x$ layer during annealing.

Chromatographic Behavior of Proteins on Stationary Phase with Aminocarboxy Ligand

Rong Li,Ming-Yang Ju,Bin Chen,Qing-Yuan Sun,Guo-Liang Chen,Mei Shi,Xiao-Gang Wang,Jian-Bin Zheng 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

An aminocarboxy aspartic acid-bonded silica (Asp-Silica) stationary phase was synthesized using L-aspartic acid as ligand and silica gel as matrix. The standard protein mixtures were separated with prepared chromatographic column. The effects of solution pH, salt concentration and metal ion on the retention of proteins were examined, and also compared with traditional iminodiacetic acid-bonded silica (IDA-Silica) column. The results show that Asp-Silica column exhibited an excellent separation performance for proteins. The retention of proteins on Asp-Silica stationary phase was consistent with electrostatic characteristic of cation-exchange. The stationary phase displayed typical metal chelate property after fixing copper ion (II) on Asp-Silica. Under competitive eluting condition, protein mixtures were effectively isolated. Asp ligand showed better ion-exchange and metal chelating properties as compared with IDA ligand.

Swelling and hydraulic characteristics of two grade bentonites under varying conditions for low-level radioactive waste repository design

Chih-Chung Chung,Guo-Liang Ren,I-Ting Chen,Che-Ju, Cuo,Hao-Chun Chang Korean Nuclear Society 2024 Nuclear Engineering and Technology Vol.56 No.4

Bentonite is a recommended material for the multiple barriers in the final disposal of low-level radioactive waste (LLW) to prevent groundwater intrusion and nuclear species migration. However, after drying-wetting cycling during the repository construction stage and ion exchange with the concrete barrier in the long-term repository, the bentonite mechanical behaviors, including swelling capacity and hydraulic conductivity, would be further influenced by the groundwater intrusion, resulting in radioactive leakage. To comprehensively examine the factors on the mechanical characteristics of bentonite, this study presented scenarios involving MX-80 and KV-1 bentonites subjected to drying-wetting cycling and accelerated ion migration. The experiments subsequently measured free swelling, swelling pressure, and hydraulic conductivity of bentonites with intrusions of seawater, high pH, and low pH solutions. The results indicated that the solutions caused a reduction in swelling volume and pressure, and an increase in hydraulic conductivity. Specifically, the swelling capability of bentonite with drying-wetting cycling in the seawater decreased significantly by 60%, while hydraulic conductivity increased by more than three times. Therefore, the study suggested minimizing drying-wetting cycling and preventing seawater intrusion, ensuring a long service life of the multiple barriers in the LLW repository.

Analysis of the Involvement of Chitin-Binding Domain of ChiCW in Antifungal Activity, and Engineering a Novel Chimeric Chitinase with High Enzyme and Antifungal Activities

Chien Jui Huang,Shu Huei Guo,Shu Chun Chung,Yu Ju Lin,Chao Ying Chen 한국미생물 · 생명공학회 2009 Journal of microbiology and biotechnology Vol.19 No.10

A simple unstructured model-based control for efficient expression of recombinant porcine insulin precursor by Pichia pastoris

Siliang Zhang,Hai-feng Hang,Wen Chen,Mei-jin Guo,Ju Chu,Ying-ping Zhuang 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.5

Based on the fact that Pichia cell growth follows a Monod equation under the condition of methanol concentration limitation, a kinetics model of recombinant methylotrophic yeast Pichia pastoris expressing porcine insulin precursor (PIP) was developed in the quasi-steady state in the induction phase. The model revealed that the relationship between specific growth rate (μ) and substrate methanol concentration was in accord with the Monod equation. The fermentation kinetic parameters maximum specific growth rate (μmax), saturation constant (Ks) and maintenance coefficient (M) were estimated to be 0.101 h−1, 0.252 g l−1, and 0.011 g MeOH g−1 DCW h−1, respectively. The unstructured model was validated in methanol induction phase with different initial cell densities. Results showed that the maximum specific protein production rate (qp.max) of 0.098 mg g−1 DCW h−1 was achieved when μ was kept at 0.016 h−1, and the maximum yield of PIP reached 0.97 g l−1, which was 1.5-fold as that of the control. Therefore, the simple Monod model proposed has proven to be a robust control system for recombinant porcine insulin precursor production by P. pastoris on pilot scale, which would be further applied on production scale.