Antibiotic resistance, biochemical typing, and PFGE typing of Bifidobacterium strains commonly used in probiotic health foods

Xu, Feili,Wang, Junping,Guo, Yunchang,Fu, Ping,Zeng, Huawei,Li, Zhigang,Pei, Xiaoyan,Liu, Xiumei,Wang, Shuo 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.2

This study firstly analyzed the antibiotic resistance, biochemical typing, and pulsed-field gel electrophoresis typing of 45 Bifidobacterium strains commonly used in health foods. Most strains were resistant to antibiotics but their antibiotic resistance rates were not high: Fos (56.52%), TET (43.48%), CRO (21.74%), AMC (15.22%), GEN (13.04%), RIF (10.87%), CHL (8.7%), CTX (6.52%), VAN (4.35%), and ERY (4.35%). The 45 strains could be divided into 14 pulsed-field gel electrophoresis types, of which the strain numbers of six pulsed-field gel electrophoresis types were more than one. All the Bifidobacterium strains could be divided into nine types by API50CHL biochemical identification. The same species displayed same biochemical typings, expect for B. animalis. Furthermore, the results confirmed that the same pulsed-field gel electrophoresis-type strains had closer antibiotic resistance patterns, and the same biochemical-type strain also had similar antibiotic resistance patterns.

Antibiotic resistance, biochemical typing, and PFGE typing of Bifidobacterium strains commonly used in probiotic health foods

Feili Xu,Junping Wang,Yunchang Guo,Huawei Zeng,Ping Fu,Zhigang Li,Xiaoyan Pei,Xiumei Liu,Shuo Wang 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.2

This study firstly analyzed the antibiotic resistance, biochemical typing, and pulsed-field gel electrophoresis typing of 45 Bifidobacterium strains commonly used in health foods. Most strains were resistant to antibiotics but their antibiotic resistance rates were not high: Fos (56.52%), TET (43.48%), CRO (21.74%), AMC (15.22%), GEN (13.04%), RIF (10.87%), CHL (8.7%), CTX (6.52%), VAN (4.35%), and ERY (4.35%). The 45 strains could be divided into 14 pulsed-field gel electrophoresis types, of which the strain numbers of six pulsed-field gel electrophoresis types were more than one. All the Bifidobacterium strains could be divided into nine types by API50CHL biochemical identification. The same species displayed same biochemical typings, expect for B. animalis. Furthermore, the results confirmed that the same pulsed-field gel electrophoresis-type strains had closer antibiotic resistance patterns, and the same biochemicaltype strain also had similar antibiotic resistance patterns.

An efficient protocol for Agrobacterium-mediated transformation of the biofuel plant Jatropha curcas by optimizing kanamycin concentration and duration of delayed selection

Qiantang Fu,Chaoqiong Li,Mingyong Tang,Yan-Bin Tao,Bang-Zhen Pan,Lu Zhang,Longjian Niu,Huiying He,Xiulan Wang,Zeng-Fu Xu 한국식물생명공학회 2015 Plant biotechnology reports Vol.9 No.6

Jatropha curcas is considered a potential biodiesel feedstock crop. Currently, the value of J. curcas is limited because its seed yield is generally low. Transgenic modification is a promising approach to improve the seed yield of J. curcas. Although Agrobacterium-mediated genetic transformation of J. curcas has been pursued for several years, the transformation efficiency remains unsatisfying. Therefore, a highly efficient and simple Agrobacterium-mediated genetic transformation method for J. curcas should be developed. We examined and optimized several key factors that affect genetic transformation of J. curcas in this study. The results showed that the EHA105 strain was superior to the other three Agrobacterium tumefaciens strains for infecting J. curcas cotyledons, and the supplementation of 100 mM acetosyringone slightly increased the transient transformation frequency. Use of the appropriate inoculation method, optimal kanamycin concentration and appropriate duration of delayed selection also improved the efficiency of stable genetic transformation of J. curcas. The percentage of b-glucuronidase positive J. curcas shoots reached as high as 56.0 %, and 1.70 transformants per explant were obtained with this protocol. Furthermore, we optimized the root-inducing medium to achieve a rooting rate of 84.9 %. Stable integration of the T-DNA into the genomes of putative transgenic lines was confirmed by PCR and Southern blot analysis. Using this improved protocol, a large number of transgenic J. curcas plantlets can be routinely obtained within approximately 4 months. The detailed information provided here for each step of J. curcas transformation should enable successful implementation of this transgenic technology in other laboratories.

Determining a Detectable Threshold of Signal Intensity in cDNA Microarray Based on Accumulated Distribution

( Xia Gao ),( Xu Ping Fu ),( Tao Li ),( Jian Zi ),( Yao Luo ),( Qing Wei ),( Er Liang Zeng ),( Yi Xie ),( Yao Li ),( Yu Min Mao ) 생화학분자생물학회 2003 BMB Reports Vol.36 No.6

In microarray data mining, one of the key problems is how to handle weak signals. Based on a bent piecewise linear accumulated distribution generally found in the microarray data, a new detectable threshold finding method is proposed to filter genes with unreliable information in this paper. More reliable and reproducible data is produced for the subsequent data mining.

HCV-Specific Interleukin-21+CD4+ T Cells Responses Associated with Viral Control through the Modulation of HCV-Specific CD8+ T Cells Function in Chronic Hepatitis C Patients

Guo-Hua Feng,Fu-Sheng Wang,Ji-Yuan Zhang,Qing-Lei Zeng,Lei Jin,Junliang Fu,Bin Yang,Ying Sun,Tianjun Jiang,Xiangsheng Xu,Zheng Zhang,Jinhong Yuan,Liyuan Wu 한국분자세포생물학회 2013 Molecules and cells Vol.36 No.4

Interleukin-21 (IL-21)+CD4+ T cells are involved in the immune response against hepatitis B virus (HBV) by secreting IL-21. However, the role of IL-21+CD4+ T cells in the immune response against chronic hepatitis C (CHC) virus infection is poorly understood. This study aimed to investigate the role of IL-21+CD4+ T cells in CHC patients and the potential mechanisms. The study subjects in-cluded nineteen CHC patients who were grouped by viral load (low, < 106 RNA copies/ml, n = 8; high, > 106 RNA copies/ml, n = 11). The peripheral frequency of HCV-specific IL-21+CD4+ T cells was higher in the low viral load group and was negatively correlated with the serum HCV RNA viral load in all CHC patients. Meanwhile, IL-21+ cells accumulated in the liver in the low viral load group. In vitro, IL-21 treatment increased the expression of proliferation markers and cytolytic molecules on HCV-specific CD8+ T cells. In summary, these findings suggest that HCV-specific IL-21+CD4+ T cells might contribute to HCV control by rescuing HCV-specific CD8+ T cells in CHC patients.

Design optimization and development of SMC composite tray

Cun-fei Wang,Zeng-fu Yang,Chengwang Shi,Xiaodong Li,Xu-feng Zhang 한양대학교 청정에너지연구소 2024 Journal of Ceramic Processing Research Vol.25 No.2

In the engineering application, trays are easy to break down to result in anchorage failure in the composite anchoring systems. Therefore, the research carried out the force analysis with mechanics of materials to observe the main stress concentration anddeformation of the tray. From the findings of the force analysis, the structure and key parameters of the tray were optimizedwith reference of the existing tray design. Besides, the study turns to the finite element software to simulate and analyze thetray. The results manifest that tray failure during the support mainly results from the expansion and deformation of the taperhole squeezed by the nut, which causes the tray taper hole to rupture and crackle extend, thus leading to its crack. What’smore, the tray breaks for the compression of the tray edge by the surrounding rock. The maximum deformation at the largeend of the optimized tray tapered hole was reduced from 33.8 mm to 4.7 mm, approximately 86% with the shear stress reducedfrom 781.67 Mpa to 258.83 Mpa, about 66.8%. Using Sheet Molding Compound (SMC) to mould trays with new structure andconducting the test of tray bearing capacity, it can be found that its bearing capacity is up to 250 KN. After the taper hole ofthe tray is locally strengthened, its bearing capacity is increased to 304 KN.

Dehydroascorbate Reductase and Glutathione Reductase Play an Important Role in Scavenging Hydrogen Peroxide during Natural and Artificial Dehydration of Jatropha curcas Seeds

Omar, Samar A.,Elsheery, Nabil I.,Kalaji, Hazem M.,Xu, Zeng-Fu,Song-Quan, Song,Carpentier, Robert,Lee, Choon-Hwan,Allakhverdiev, Suleyman I. 한국식물학회 2012 Journal of Plant Biology Vol.55 No.6

Changes in $H_2O_2$ and the main antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR), in endospermic and embryonic tissues were studied in developing and artificially dried Jatropha curcas seeds. Immature seeds were desiccation-tolerant at 80 days after flowering, as they were able to germinate fully after artificial drying on silica gel had reduced their water content to 10-12% of fresh weight. In both endospermic and embryonic tissues, $H_2O_2$ level and, consequently, lipid peroxide content, decreased during seed development as well as after artificial dehydration of developing seeds. All examined antioxidant enzymes except DHAR showed a decrease in total activity in mature stages as compared with early stages. Expression analysis of SOD genes revealed that the decrease in total SOD activities was related to the decrease in Cu/Zn-SOD expression, while the continuous activity of SOD during maturation was related to an increase in Mn-SOD expression. Artificial drying resulted in increased SOD and DHAR activity, irrespective of the developmental stage. Our results revealed weak participation of CAT and APX in $H_2O_2$ scavenging, as well as no significant alterations in GR activities either during maturation or after artificial drying. Changes in SOD and GR isoenzyme patterns occurred during maturation-related drying, but not after artificial drying. These results highlight the role of ascorbate-glutathione cycle enzymes (DHAR and GR) in $H_2O_2$ scavenging during maturation or after artificial drying of developing J. curcas seeds.

Erratum to: Dehydroascorbate reductase and glutathione reductase play an important role in scavenging hydrogen peroxide during natural and artificial dehydration of Jatropha curcas seeds

Samar A. Omar,Nabil I. Elsheery,Hazem M. Kalaji,Zeng-Fu Xu,Song Song-Quan,Robert Carpentier,이춘환,Suleyman I. Allakhverdiev 한국식물학회 2013 Journal of Plant Biology Vol.56 No.4

Changes in H2O2 and the main antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR), in endospermic and embryonic tissues were studied in developing and artificially dried Jatropha curcas seeds. Immature seeds were desiccation-tolerant at 80 days after flowering, as they were able to germinate fully after artificial drying on silica gel had reduced their water content to 10–12% of fresh weight. In both endospermic and embryonic tissues, H2O2 level and, consequently, lipid peroxide content, decreased during seed development as well as after artificial dehydration of developing seeds. All examined antioxidant enzymes except DHAR showed a decrease in total activity in mature stages as compared with early stages. Expression analysis of SOD genes revealed that the decrease in total SOD activities was related to the decrease in Cu/Zn-SOD expression, while the continuous activity of SOD during maturation was related to an increase in Mn-SOD expression. Artificial drying resulted in increased SOD and DHAR activity, irrespective of the developmental stage. Our results revealed weak participation of CAT and APX in H2O2 scavenging, as well as no significant alterations in GR activities either during maturation or after artificial drying. Changes in SOD and GR isoenzyme patterns occurred during maturation-related drying, but not after artificial drying. These results highlight the role of ascorbate-glutathione cycle enzymes (DHAR and GR) in H2O2 scavenging during maturation or after artificial drying of developing J. curcas seeds.

Identification and differential expression of two dehydrin cDNAs during maturation of Jatropha curcas seeds.

Omar, S A,Elsheery, N I,Kalaji, H M,Ebrahim, M K H,Pietkiewicz, S,Lee, C-H,Allakhverdiev, S I,Xu, Zeng-Fu Consultants Bureau [etc.] 2013 Biochemistry Vol.78 No.5

<P>Plant dehydrin proteins (DHNs) are known to be important for environmental stress tolerance and are involved in various developmental processes. Two full-length cDNAs JcDHN-1 and JcDHN-2 encoding two dehydrins from Jatropha curcas seeds were identified and characterized. JcDHN-1 is 764 bp long and contains an open reading frame of 528 bp. The deduced JcDHN-1 protein has 175 a.a. residues that form a 19.3-kDa polypeptide with a predicted isoelectric point (pI) of 6.41. JcDHN-2 is 855 bp long and contains an open reading frame of 441 bp. The deduced JcDHN-2 protein has 156 a.a. residues that form a 17.1-kDa polypeptide with a predicted pI of 7.09. JcDHN-1 is classified as type Y3SK2 and JcDHN-2 is classified as type Y2SK2 according to the YSK shorthand for structural classification of dehydrins. Homology analysis indicates that both JcDHN-1 and JcDHN-2 share identity with DHNs of other plants. Analysis of the conserved domain revealed that JcDHN-2 has glycoside hydrolase GH20 super-family activity. Quantitative real time PCR analysis for JcDHN-1 and JcDHN-2 expression during seed development showed increasing gene expression of both their transcript levels along with the natural dehydration process during seed development. A sharp increase in JcDHN-2 transcript level occurred in response to water content dropping from 42% in mature seeds to 12% in dry seeds. These results indicate that both JcDHNs have the potential to play a role in cell protection during dehydration occurring naturally during jatropha orthodox seed development.</P>