Synergistic growth in bacteria depends on substrate complexity

Yi-Jie Deng,Shiao Y. 한국미생물학회 2016 The journal of microbiology Vol.54 No.1

Both positive and negative interactions among bacteria take place in the environment. We hypothesize that the complexity of the substrate affects the way bacteria interact with greater cooperation in the presence of recalcitrant substrate. We isolated lignocellulolytic bacteria from salt marsh detritus and compared the growth, metabolic activity and enzyme production of pure cultures to those of three-species mixed cultures in lignocellulose and glucose media. Synergistic growth was common in lignocellulose medium containing carboxyl methyl cellulose, xylan and lignin but absent in glucose medium. Bacterial synergism promoted metabolic activity in synergistic mixed cultures but not the maximal growth rate (μ). Bacterial synergism also promoted the production of β- 1,4-glucosidase but not the production of cellobiohydrolase or β-1,4-xylosidase. Our results suggest that the chemical complexity of the substrate affects the way bacteria interact. While a complex substrate such as lignocellulose promotes positive interactions and synergistic growth, a labile substrate such as glucose promotes negative interactions and competition. Synergistic interactions among indigenous bacteria are suggested to be important in promoting lignocellulose degradation in the environment.

Designed synthesis and characterization of nanostructured ceria-zirconia based material with enhanced thermal stability and its application in three-way catalysis

Jie Deng,Yi Zhou,Shanshan Li,Lei Xiong,Jianli Wang,Shandong Yuan,Yaoqiang Chen 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.64 No.-

Three CeO2–ZrO2–Y2O3–La2O3 (CZ) nanomaterials with controllable crystallite size were prepared by a simple co-precipitation method combined with hydrothermal treatment at different temperatures. The material CZ-180 possesses a high surface area of 43.6 m2 g−1 and a low reduction temperature of 344 °C simultaneously even after aging at 1000 °C for 4 h. Moreover, with improving hydrothermal temperature, the incorporation of rear earth metals was accelerated and surface properties were modified. And higher Pd dispersion and larger proportion of active Pd2+ species were achieved on the modified surface of CZ-180. Consequently, the supported catalyst Pd/CZ-180 shows a superior three-way catalytic performance.

Decomposition Properties of Trifluoroiodomethane under Discharges and Interruptions

Fan-Yi Cai,Dong-Xian Tan,Bai-Jie Zhou,Jian Xue,Deng-Ming Xiao 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.6

This paper is devoted to detecting decomposition characteristics of Iodotrifluoromethane (CF3I) under alternating current (AC) discharges or load current interruptions. The decomposition products are measured utilizing chromatography-mass spectroscopy. It is found that less than 1% CF3I gas decomposed after several interruptions at load current of 200 A or hundred times of AC discharges. However, under interruptions at a current of 400 A, more than 95% CF3I gas decomposed into carbon tetrafluoride (CF4) and hexafluoroethane (C2F6). The equilibrium compositions based on Gibbs free energy minimization of CF3I was calculated to explain the decomposition mechanism.

Ginsenoside Rg3 in combination with artesunate overcomes sorafenib resistance in hepatoma cell and mouse models

Ying-Jie Chen,Jia-Ying Wu,Yu-Yi Deng,Ying Wu,Xiao-Qi Wang,Amy Sze-man Li,Lut Yi Wong,Xiuqiong Fu,Zhi-Ling Yu,Chun Liang 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.3

Sorafenib is effective in treating hepatoma, but most patients develop resistance to it. STAT3signaling has been implicated in sorafenib resistance. Artesunate (ART) and 20(R)-ginsenoside Rg3 (Rg3)have anti-hepatoma effects and can inhibit STAT3 signaling in cancer cells. This study aimed to evaluatethe effects of Rg3 in combination with ART (Rg3-plus-ART) in overcoming sorafenib resistance, and toexamine the involvement of STAT3 signaling in these effects. Methods: Sorafenib-resistant HepG2 cells (HepG2-SR) were used to evaluate the in vitro anti-hepatomaeffects of Rg3-plus-ART. A HepG2-SR hepatoma-bearing BALB/c-nu/nu mouse model was used to assessthe in vivo anti-hepatoma effects of Rg3-plus-ART. CCK-8 assays and Annexin V-FITC/PI double stainingwere used to examine cell proliferation and apoptosis, respectively. Immunoblotting was employed toexamine protein levels. ROS generation was examined by measuring DCF-DA fluorescence. Results: Rg3-plus-ART synergistically reduced viability of, and evoked apoptosis in HepG2-SR cells, andsuppressed HepG2-SR tumor growth in mice. Mechanistic studies revealed that Rg3-plus-ART inhibitedactivation/phosphorylation of Src and STAT3 in HepG2-SR cultures and tumors. The combination alsodecreased the STAT3 nuclear level and induced ROS production in HepG2-SR cultures. Furthermore, overactivation of STAT3 or removal of ROS diminished the anti-proliferative effects of Rg3-plus-ART, andremoval of ROS diminished Rg3-plus-ART's inhibitory effects on STAT3 activation in HepG2-SR cells. Conclusions: Rg3-plus-ART overcomes sorafenib resistance in experimental models, and inhibition of Src/STAT3 signaling and modulation of ROS/STAT3 signaling contribute to the underlying mechanisms. Thisstudy provides a pharmacological basis for developing Rg3-plus-ART into a novel modality for treatingsorafenib-resistant hepatoma.

Biocatalysis and Fermentation Technology : Secretory Expression, Functional Characterization, and Molecular Genetic Analysis of Novel Halo-Solvent-Tolerant Protease from Bacillus gibsonii

( Ai Hua Deng ),( Guo Qiang Zhang ),( Na Na Shi ),( Jie Wu ),( Fu Ping Lu ),( Ting Yi Wen ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.2

A novel protease gene from Bacillus gibsonii, aprBG, was cloned, expressed in B. subtilis, and characterized. High-level expression of aprBG was achieved in the recombinant strain when a junction was present between the promoter and the target gene. The purified recombinant enzyme exhibited similar N-terminal sequences and catalytic properties to the native enzyme, including high affinity and hydrolytic efficiency toward various substrates and a superior performance when exposed to various metal ions, surfactants, oxidants, and commercial detergents. AprBG was remarkably stable in 50% organic solvents and retained 100% activity and stability in 0-4 M NaCl, which is better than the characteristics of previously reported proteases. AprBG was most closely related to the high-alkaline proteases of the subtilisin family with a 57-68% identity. The secretion and maturation mechanism of AprBG was dependent on the enzyme activity, as analyzed by site-directed mutagenesis. Thus, when taken together, the results revealed that the halo-solvent-tolerant protease AprBG displays significant activity and stability under various extreme conditions, indicating its potential for use in many biotechnology applications.

Decomposition Properties of Trifluoroiodomethane under Discharges and Interruptions

Cai, Fan-Yi,Tan, Dong-Xian,Zhou, Bai-Jie,Xue, Jian,Xiao, Deng-Ming The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.6

This paper is devoted to detecting decomposition characteristics of Iodotrifluoromethane ($CF_3I$) under alternating current (AC) discharges or load current interruptions. The decomposition products are measured utilizing chromatography-mass spectroscopy. It is found that less than 1% $CF_3I$ gas decomposed after several interruptions at load current of 200 A or hundred times of AC discharges. However, under interruptions at a current of 400 A, more than 95% $CF_3I$ gas decomposed into carbon tetrafluoride ($CF_4$) and hexafluoroethane ($C_2F_6$). The equilibrium compositions based on Gibbs free energy minimization of $CF_3I$ was calculated to explain the decomposition mechanism.

Depression and the Risk of Breast Cancer: A Meta-Analysis of Cohort Studies

Sun, Hui-Lian,Dong, Xiao-Xin,Cong, Ying-Jie,Gan, Yong,Deng, Jian,Cao, Shi-Yi,Lu, Zu-Xun Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Background: Whether depression causes increased risk of the development of breast cancer has long been debated. We conducted an updated meta-analysis of cohort studies to assess the association between depression and risk of breast cancer. Materials and Methods: Relevant literature was searched from Medline, Embase, Web of Science (up to April 2014) as well as manual searches of reference lists of selected publications. Cohort studies on the association between depression and breast cancer were included. Data abstraction and quality assessment were conducted independently by two authors. Random-effect model was used to compute the pooled risk estimate. Visual inspection of a funnel plot, Begg rank correlation test and Egger linear regression test were used to evaluate the publication bias. Results: We identified eleven cohort studies (182,241 participants, 2,353 cases) with a follow-up duration ranging from 5 to 38 years. The pooled adjusted RR was 1.13(95% CI: 0.94 to 1.36; $I^2=67.2%$, p=0.001). The association between the risk of breast cancer and depression was consistent across subgroups. Visual inspection of funnel plot and Begg's and Egger's tests indicated no evidence of publication bias. Regarding limitations, a one-time assessment of depression with no measure of duration weakens the test of hypothesis. In addition, 8 different scales were used for the measurement of depression, potentially adding to the multiple conceptual problems concerned with the definition of depression. Conclusions: Available epidemiological evidence is insufficient to support a positive association between depression and breast cancer.

Single Nucleotide Polymorphisms of NLRP12 Gene and Association with Non-specific Digestive Disorder in Rabbit

Liu, Yun-Fu,Zhang, Gong-Wei,Xiao, Zheng-Long,Yang, Yu,Deng, Xiao-Song,Chen, Shi-Yi,Wang, Jie,Lai, Song-Jia Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.8

The NLRP12 (NLR family, pyrin domain containing 12) serves as a suppressor factor in the inflammatory response and protects the host against inflammation-induced damage. In the present study, we aimed to study the polymorphisms of NLRP12 gene and its association with susceptibility to non-specific digestive disorder (NSDD) in rabbits. We re-sequenced the entire coding region of the rabbit NLRP12 gene and detected a total of 19 SNPs containing 14 synonymous and five non-synonymous variations. Among them, the coding SNP (c.1682A>G), which would carry a potential functional implication, was subsequently subjected to genotyping for case-control association study (272 cases and 267 controls). The results revealed that allele A was significantly protective against NSDD with an odds ratio value of 0.884 (95% confidence interval, 0.788 to 0.993; p = 0.038). We also experimentally induced NSDD in growing rabbits by feeding a fibre-deficient diet and subsequently investigated NLRP12 mRNA expression. The mRNA expression of NLRP12 in healthy status was significantly higher than that in severe NSDD (p = 0.0016). The highest expression was observed in individuals carrying the protective genotype AA (p = 0.0108). These results suggested that NLRP12 was significantly associated with the NSDD in rabbits. However, the precise molecular mechanism of NLRP12 involving in the development of rabbit NSDD requires further research.