Isolation of NH4+-Tolerant Mutants of Actinobacillus succinogenes for Succinic Acid Production by Continuous Selection

( Gui Zi Ye ),( Min Jiang ),( Jian Li ),( Ke Quan Chen ),( Yong Lan Xi ),( Shu Wen Liu ),( Ping Wei ),( Ping Kai Ouyang ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.8

Actinobacillus succinogenes, a representative succinic-acid-producing microorganism, is seriously inhibited by ammonium ions, thereby hampering the industrial use of A. succinogenes with ammonium-ion-based materials as the pH controller. Therefore, this study isolated an ammonium-ion-tolerant mutant of A. succinogenes using a continuous-culture technique in which all the environmental factors, besides the stress (ammonium ions), were kept constant. Instead of operating the mutant-generating system as a nutrient-limited chemostat, it was used as a nutrientunlimited system, allowing the cells to be continuously cultured at the maximum specific growth rate. The mutants were isolated on agar plates containing the acid-base indicator bromothymol blue and a high level of ammonium ions that would normally kill the parent strain by 100%. When cultured in anaerobic bottles with an ammonium ion concentration of 354 mmol/l, the mutant YZ0819 produced 40.21 g/l of succinic acid with a yield of 80.4%, whereas the parent strain NJ113 was unable to grow. When using NH4OH to buffer the culture pH in a 3.0 l stirred bioreactor, YZ0819 produced 35.15 g/l of succinic acid with a yield of 70.3%, which was 155% higher than that produced by NJ113. In addition, the morphology of YZ0819 changed in the fermentation broth, as the cells were aggregated from the beginning to the end of the fermentation. Therefore, these results indicate that YZ0819 can efficiently produce succinic acid when using NH4OH as the pH controller, and the formation of aggregates can be useful for transferring the cells from a cultivation medium for various industrial applications.

Development of AFLP and SCAR Markers Linked to a Recessive Genic Male Sterile Gene (Bnms3) in Rapeseed for Marker-assisted Selection

Gui Chun Wang,Jun Ping He,Deng Feng Hong,Yan Zhou Xie,Zheng Hua Xu,Ping Wu Liu,Guang Sheng Yang 한국유전학회 2007 Genes & Genomics Vol.29 No.4

9012AB is a recessive genic male sterility (RGMS) line in rapeseed, of which the male sterility is controlled by two pairs of recessive duplicate male sterile genes (Bnms3 and Bnms4) interacting with a recessive epistatic suppressor gene (esp). The recessive homozygosity at the esp locus (espesp) can suppress the expression of the recessive male sterility trait in homozygous plants (Bnms3Bnms3Bnms4Bnms4) and result in fertility restoration. A F2 population of 188 plants, derived from self-pollinated progenies of a 9012 AB fertile plants (BnMs3Bnms3Bnms4Bnms4EspEsp), was conducted to identify molecular markers linked to the recessive male sterility gene (Bnms3). By amplified fragment length polymorphism (AFLP) assay combining with bulked segregant analysis (BSA), 13 markers linked to Bnms3 were identified. Linkage analysis indicated that 13 AFLP markers were tightly linked to the Bnms3 gene with a genetic distance varying from 1.3 cM to 7.1 cM. Among them, one marker was co-dominant marker, 6 markers were in coupling phase with Bnms3, and the others were in repulsion phase with Bnms3 gene, One AFLP marker with a genetic distance of 1.4cM was further converted into a SCAR marker successfully, which have been applied in marker-assisted selection of RGMS lines and their temporary maintainers effectively.

Effects of Transglutaminase on Wheat Flour Dough Mixed with Caffeic Acid and Xylanase

Gui Ping Wei,고봉경 계명대학교 자연과학연구소 2017 Quantitative Bio-Science Vol.36 No.2

Our study investigated the effects of the non-disulfide cross-linking enzyme transglutaminase (TG) on depolymerized dough when mixed with caffeic acid (CA) or endo-xylanase (XY). Both CA and XY significantly decreased the resistance to extension (Rmax) of the dough and increased its extensibility (E value). The reduced Rmax and increased E value with CA were restored by TG. However, TG had no effect on XY-added dough. Changes in paste viscosities were most apparent with the addition of XY. The decreased paste viscosity induced by XY was not restored by TG. TG with/without CA or XY did not improve the bread volume; XY alone significantly enhanced bread volume. Our results showed that a combination of TG and CA is effective to improve dough properties, but not TG and XY. Our study indicated that TG improves dough properties when phenolic acid is used to as a reducing agent of gluten’s disulfide cross-linkages. However, it has no effect when endo-xylanase is used to hydrolyze arabinoxylan’s glycoside linkages.

The genetic engineering of glycine betaine synthesis in tobacco improves the resistance of the photosynthetic apparatus to drought stress

Wang Gui-Ping,Xue Xiao-Min,Yang Xing-hong,Chen Ru,Han Xue-Ping 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.2

In recent years, with the global climate change, the intensity, frequency and duration of drought have increased significantly, which has become the main limiting factor for agricultural development in many areas. Glycine betaine (GB) is an effec- tive stress-resistant substance. In this experiment, the effects of the genetic engineering of GB synthesis on photosynthetic apparatus of tobacco under drought stress were studied using transgenic tobacco (T) accumulating GB and wild-type tobacco (K326, WT). Potted tobaccos were subjected to drought stress (controlled irrigation, 25 °C ± 1 °C, a relative humidity: 75–80%) for 9 days, photosynthetic gas exchange parameters, chlorophyll a fluorescence, structure of chloroplast and thyla- koid membrane, and protein function of thylakoid membrane were examined under different drought stress time (days). The results showed that T tobacco could accumulate GB and the accumulated GB improved the resistance of the photosynthetic apparatus to drought stress. Under drought stress, the damage of chloroplast and thylakoid lamellae in T tobacco was less than that in WT tobacco, the accumulation of GB in T tobacco could maintain the stability of thylakoid membrane, improved the unsaturated fatty acid index (IUFA) of thylakoid membrane lipid, increased the contents of digalactosyl diacylglycerol (DGDG) and phosphatidylglycerol (PG), and decreased the ratio of monogalactosyl diaylglycerol (MGDG) to DGDG. In addition, under drought stress, the accumulation of GB in T tobacco alleviated the photo-inhibition of PSII, and the increase of xanthophyll cycle de-epoxidation may be one of the reasons for the enhancement of PSII function.

High-Velocity Impact of Carbon/Epoxy Composite Laminates

Zhao, Gui Ping,Wang, Zheng Hao,Zhang, Jian Xin,Cho, Chong Du Trans Tech Publications, Ltd. 2007 Key Engineering Materials Vol.334-335 No.1

<P>The response of Carbon/epoxy composites under high velocity impact was investigated experimentally. The strain rate dependent behavior of T300 Carbon/epoxy matrix composite in tension is studied experimentally by split Hopkinson bar technique. Dynamic stress-strain plot was obtained and compared with the quasi-static tensile test results. The results of the study indicate that Carbon/epoxy composites are strain rate dependent materials. Stacking sequence has a significant effect on the material response. Tensile strength of the composites all increased with increasing strain rate. And failure strain decreased when strain rate increased.</P>

Simulation and Experimental Investigation of Impact Damage in Composite Shell

Zhao, Gui Ping,Cho, Chong Du,Kwon, Oh Yang Trans Tech Publications, Ltd. 2005 Key Engineering Materials Vol.297 No.-

<P>In this paper, the energy absorption characteristics on extruded aluminum box-section strengthened with carbon-fiber-reinforced plastics (CFRP) laminates and/or foam material were investigated under impact loading. Impact tests using a pneumatic impact tester were conducted with the specimens in three-point bending flexure with consideration given to the side-door impact beams in vehicles. The absorbed energy to the specimen during the impact was determined from the loaddisplacement curve, which was obtained from the strain gauge attached to the impactor and the laser displacement transducer. From the results, it was found that the strengthening by externally bonding with CFRP laminates improved the impact-induced energy absorption. Also, the effect of the improvement was clearly seen in the case of the use of filling form material in the aluminum extrusion together with attaching CFRP laminates.</P>

Improvement of heat and drought photosynthetic tolerance in wheat by overaccumulation of glycinebetaine

Wang, Gui-Ping,Hui, Zhen,Li, Feng,Zhao, Mei-Rong,Zhang, Jin,Wang, Wei The Korean Society of Plant Biotechnology 2010 Plant biotechnology reports Vol.4 No.3

Within their natural habitat, crops are often subjected to drought and heat stress, which suppress crop growth and decrease crop production. Causing overaccumulation of glycinebetaine (GB) has been used to enhance the crop yield under stress. Here, we investigated the response of wheat (Triticum aestivum L.) photosynthesis to drought, heat stress and their combination with a transgenic wheat line (T6) overaccumulating GB and its wild-type (WT) Shi4185. Drought stress (DS) was imposed by controlling irrigation until the relative water content (RWC) of the flag leaves decreased to between 78 and 82%. Heat stress (HS) was applied by exposing wheat plants to $40^{\circ}C$ for 4 h. A combination of drought and heat stress was applied by subjecting the drought-stressed plants to a heat stress as above. The results indicated that all stresses decreased photosynthesis, but the combination of drought and heat stress exacerbated the negative effects on photosynthesis more than exposure to drought or heat stress alone. Drought stress decreased the transpiration rate (Tr), stomatal conductance (Gs) and intercellular $CO_2$ concentration (Ci), while heat stress increased all of these; the deprivation of water was greater under drought stress than heat stress, but heat stress decreased the antioxidant enzyme activity to a greater extent. Overaccumulated GB could alleviate the decrease of photosynthesis caused by all stresses tested. These suggest that GB induces an increase of osmotic adjustments for drought tolerance, while its improvement of the antioxidative defense system including antioxidative enzymes and antioxidants may be more important for heat tolerance.

Triterpenoid Saponins from the Seeds of Caragana microphylla

Gui-Lin Jin,Cheng-Jian Zheng,Wen-Bo Xin,Zhu-Jun Mao,Pei-Xin Sun,Zhi-Xin Zeng,Lu-Ping Qin 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

Two new triterpenoid saponins, namely caraganoside C (1) and caraganoside D (2), were isolated from the seeds of Caragana microphylla. Their structures were elucidated on the basis of spectroscopic analyses, including homo- and hetero-nuclear correlation NMR experiments (COSY, HSQC and HMBC). Both 1 and 2 exhibited moderate inhibitory activity against NO production in LPS-stimulated RAW264.7 cells with IC_50 values of 26.4 μM and 32.2 μM, respectively. In addition, 1 showed weak cytotoxicity against MCF-7, HL-60, HCT116, and A549 cell lines.

中韓社會保障制度比較硏究

( Gui Zhen Heng ),( Fan Ping ) 한국행정학회 2010 한국행정학회 학술발표논문집 Vol.2010 No.-

Structural-based Screening of L-phenylglycine Aminotransferase using L-phenylalanine as the Optimal Amino Donor: Recycling of L-phenylalanine to Produce L-phenylglycine

Shuang Ping Liu,Rui Xia Liu,Jian Mao,Liang Zhang,Zhongyang Ding,Zhenghua Gu,Gui-Yang Shi 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.1

The aproteinogenic amino acid, L-phenylglycine, is an important side chain building block for some drugs. It would be of great commercial and environmental value to biocatalyse L-phenylalanine to L-phenylglycine, and thus replace the organic synthesis method. To produce Lphenylglycine from L-phenylalanine, an L-phenylglycine aminotransferase was screened and characterized. HpgTAO showed high homology to α-aminoadipate aminotransferase. The L-phenylalanine binding site was near the residues S26, R401, N201, and G46 in HpgTAO, and L-phenylalanine formed a hydrogen bond with Asn20, which was similar to the substrate binding mechanism of α-aminoadipate aminotransferase. HpgTAO showed increased activity in alkalescent environment below 40°C. The kinetic analysis showed that L-phenylalanine had the highest affinity to HpgTAO, which ensured the recycle biosynthesis of Lphenylglycine from L-phenylalanine. To date, it was the only aminotransferase using L-phenylalanine as an optimal amino donor. The L-phenylglycine biocatalysis operon was also constructed by co-expressing the hmaS, hmo and hpgT by a single plasmid. The first in vitro conversion of Lphenylalanine to L-phenylglycine was achieved by directly using the L-phenylalanine fermentation broth as the raw material.