Fumigant Activity of Volatiles from Streptomyces alboflavus TD-1 against Fusarium moniliforme Sheldon

Zhifang Wang,Changlu Wang,Fengjuan Li,Zhenjing Li,Mianhua Chen,Yurong Wang,Xi Qiao,Hong Zhang 한국미생물학회 2013 The journal of microbiology Vol.51 No.4

The fumigant activity of volatiles generated by Streptomyces alboflavus TD-1 against Fusarium moniliforme Sheldon was investigated. The results showed that the mycelial growth,sporulation, and spore germination of F. moniliforme were significantly suppressed, and that membrane permeability was disrupted in the presence of the volatiles. Gas chromatography-mass Spectrometry analysis revealed 31 kinds of volatile organic compound from the volatiles. Among them,two earthy-smelling substances, namely, 2-methylisoborneol (50.97%) and trans-1,10-dimethyl-trans-9-decalinol (3.10%)were found. The most abundant compound, 2-methylisoborneol,exhibited inhibitory activity against F. moniliforme by fumigation. All these results suggested that S. alboflavus TD-1 can be a promising starter for the inhibition of F. moniliforme through fumigant action.

Phylogenetic Analysis on the Bacteria Producing Non-Volatile Fungistatic Substances

ZhiFang Li,ChangSong Zou,YueQiu He,MingHe Mo,KeQin Zhang 한국미생물학회 2008 The journal of microbiology Vol.46 No.3

This study characterized the soil bacteria producing non-volatile fungistatic substances. Among the 2,100 colonies of soil bacteria randomly isolated from seven agricultural soil samples, 518 isolates (24.67% of total) showed fungistatic activity toward nematophagous fungi Paecilomyces lilacinus and Trichoderma viride by producing non-volatile substances. A phylogenetic analysis based on amplified ribosomal DNA restriction analysis (ARDRA) and 16S rDNA sequence placed the 518 bacteria in three groups of the domain Bacteria: Actinomycetales, Bacillales, and Gammaproteobacteria. Three genera, Arthrobacter, Bacillus, and Pseudomonas, were the most frequently encountered groups.

Identifying natural genotypes of grain number per panicle in rice (Oryza sativa L.) by association mapping

Jianyin Xie,Fengmei Li,Najeeb Ullah Khan,Xiaoyang Zhu,Xueqiang Wang,Zhifang Zhang,Xiaoqian Ma,Yan Zhao,Quan Zhang,Shuyang Zhang,Zhanying Zhang,Jinjie Li,Zichao Li,Hongliang Zhang 한국유전학회 2019 Genes & Genomics Vol.41 No.3

Introduction As one of the main yield components, grain number per panicle (GNP) played critical role in the rice yield improvement. The identification of natural advantageous variations under different situations will promote the sustainable genetic improvement in rice yield. Objectives This study was designed to identify natural genotypes in a rice mini-core collection, to examine the genotypic effects across the indica and japonica genetic background in different environments, and excavating the superior genotypes that had drove the modern genetic improvement. Methods The association mapping of GNP was carried out using a mini-core collection including 154 indica and 119 japonica accessions in seven different environments. Genotypic effects of each genotype for each QTL were calculated and genotype frequency distortion between the commercial rice cultivars and landraces was screened by χ2-test. Results In total, 74 QTLs containing stable and sensitive QTLs in various environments were detected. Within them, 20 positive and 24 negative genotypes in indica, and 24 positive and 16 negative genotypes in japonica were identified. When checking the accumulation of positive genotypes identified in indica across cultivars in each of the two subspecies, it indicated that increased number of positive genotypes identified in indica results in the substantially increased GNP in both indica and japonica across all of the environments, while this trend was not obvious for the positive genotypes identified in japonica especially in short day environments. Moreover, the positive and negative genotype frequency distortion between the landraces and commercial rice cultivars indicated that both positive selection of positive genotypes and negative selection of negative genotypes had driven the genetic improvement on GNP. Conclusion Our findings suggested that the accumulation of positive genotypes and purifying negative genotypes played equivalently important roles in the improvement of rice yield, but the efficient use for some QTLs or genotypes depends on the comprehensive evaluation of their effect under diverse genetic backgrounds and environments.

TNF-α-Induced SOX5 Upregulation Is Involved in the Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells Through KLF4 Signal Pathway

Lijun Xu,Lili Zheng,Zhifang Wang,Chong Li,Shan Li,Xuedi Xia,Pengyan Zhang,Li Li,Lixia Zhang 한국분자세포생물학회 2018 Molecules and cells Vol.41 No.6

Postmenopausal osteoporosis (PMOP) is a common sys-temic skeletal disease characterized by reduced bone mass and microarchitecture deterioration. Although differentially expressed SOX5 has been found in bone marrow from ovariectomized mice, its role in osteogenic differentiation in human mesenchymal stem cells (hMSCs) from bone marrow in PMOP remains unknown. In this study, we investigated the biological function of SOX5 and explore its molecular mechanism in hMSCs from patients with PMOP. Our findings showed that the mRNA and protein expression levels of SOX5 were upregulated in hMSCs isolated from bone marrow samples of PMOP patients. We also found that SOX5 overexpression decreased the alkaline phosphatase (ALP) activity and the gene expression of osteoblast markers including Collagen I, Runx2 and Osterix, which were increased by SOX5 knockdown using RNA interference. Furthermore, TNF- notably upregulated the SOX5 mRNA expression level, and SOX5 knockdown reversed the effect of TNF- on osteogenic differentiation of hMSCs. In addition, SOX5 overexpression increased Kruppel-like factor 4 (KLF4) gene expression, which was decreased by SOX5 silencing. KLF4 knockdown abrogated the suppressive effect of SOX5 overexpression on osteogenic differentiation of hMSCs. Taken together, our results indicated that TNF--induced SOX5 upregulation inhibited osteogenic differentiation of hMSCs through KLF4 signal pathway, suggesting that SOX5 might be a novel therapeutic target for PMOP treatment.

TNF-α-Induced SOX5 Upregulation Is Involved in the Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells Through KLF4 Signal Pathway

Xu, Lijun,Zheng, Lili,Wang, Zhifang,Li, Chong,Li, Shan,Xia, Xuedi,Zhang, Pengyan,Li, Li,Zhang, Lixia Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.6

Postmenopausal osteoporosis (PMOP) is a common systemic skeletal disease characterized by reduced bone mass and microarchitecture deterioration. Although differentially expressed SOX5 has been found in bone marrow from ovariectomized mice, its role in osteogenic differentiation in human mesenchymal stem cells (hMSCs) from bone marrow in PMOP remains unknown. In this study, we investigated the biological function of SOX5 and explore its molecular mechanism in hMSCs from patients with PMOP. Our findings showed that the mRNA and protein expression levels of SOX5 were upregulated in hMSCs isolated from bone marrow samples of PMOP patients. We also found that SOX5 overexpression decreased the alkaline phosphatase (ALP) activity and the gene expression of osteoblast markers including Collagen I, Runx2 and Osterix, which were increased by SOX5 knockdown using RNA interference. Furthermore, $TNF-{\alpha}$ notably upregulated the SOX5 mRNA expression level, and SOX5 knockdown reversed the effect of $TNF-{\alpha}$ on osteogenic differentiation of hMSCs. In addition, SOX5 overexpression increased Kruppel-like factor 4 (KLF4) gene expression, which was decreased by SOX5 silencing. KLF4 knockdown abrogated the suppressive effect of SOX5 overexpression on osteogenic differentiation of hMSCs. Taken together, our results indicated that $TNF-{\alpha}$-induced SOX5 upregulation inhibited osteogenic differentiation of hMSCs through KLF4 signal pathway, suggesting that SOX5 might be a novel therapeutic target for PMOP treatment.

Preliminary numerical study of single bubble dynamics in swirl flow using volume of fluid method

Li, Zhongchun,Qiu, Zhifang,Du, Sijia,Ding, Shuhua,Bao, Hui,Song, Xiaoming,Deng, Jian Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.4

Spacer grid with mixing vane had been widely used in nuclear reactor core. One of the main feather of spacer grid with mixing vane was that strong swirl flow was formed after the spacer grid. The swirl flow not only changed the bubble generation in the near wall field, but also affected the bubble behaviors in the center region of the subchannel. The interaction between bubble and the swirl flow was one of the basic phenomena for the two phase flow modeling in fuel assembly. To obatin better understanding on the bubble behaviors in swirl flow, full three dimension numerical simulations were conducted in the present paper. The swirl flow was assumed in the cylindral calculation domain. The bubble interface was captured by Volume Of Fluid (VOF) method. The properties of saturated water and steam at different pressure were applied in the simulation. The bubble trajectory, motion, shape and force were obtained based on the bubble parameters captured by VOF. The simulation cases in the present study included single bubble with different size, at different angular velocity conditions and at different pressure conditions. The results indicated that bubble migrated to the center in swirl flow with spiral motion type. The lateral migration was mainly related to shear stress magnitude and bubble size. The bubble moved toward the center with high velocity when the swirl magnitude was high. The largest bubble had the highest lateral migration velocity in the present study range. The effect of pressure was small when bubble size was the same. The prelimenery simulation result would be beneficial for better understanding complex two phase flow phenomena in fuel assembly with spacer grid.

One-pot Synthesis of Hierarchical Mesoporous ZSM-5 from the Assembly of Nanocrystals Using Urea as Additive

Yuanyuan Ma,Zhifang Li,Nan Zhao,Fuzhong Han,Qiubin Kan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.03

A hierarchical mesoporous ZSM-5 catalyst with aggregated nanocrystals structure was one-pot hydrothermally synthesized by using urea as the additive. The crystalline phase, morphology and hierarchical architectures were characterized by the XRD, SEM, TEM and N2 adsorption/desorption analyses. The nano-aggregates showed MFI crystalline phase and were composed of connected nanoparticles. The samples had the high surface area and the pore volume from intercrystalline among the nanoparticles due to spontaneously stacking of nanocrystals. The pyridine-adsorbed FTIR and the catalytic performances in the alkylation of phenol and tert-butyl alcohol were applied to evaluate the accessibility of acid sites and the catalytic activities for the hierarchical mesoporous ZSM-5 samples. The samples possessed high accessibility of acid sites which resulted from their large amount of mesopores, and its catalytic activity was improved dramatically. The phenol conversion could reach up to 95.6%, and the corresponding selectivity of 4-TBP and 2,4-DTBP was 44% and 51.5%, respectively.

Bacillus megaterium Strain XTBG34 Promotes Plant Growth by Producing 2-Pentylfuran

Changsong Zou,Zhifang Li,Diqiu Yu 한국미생물학회 2010 The journal of microbiology Vol.48 No.4

Several chemical changes in soil are associated with plant growth-promoting rhizobacteria. An endosporeforming bacterium, strain XTBG34, was isolated from a Xishuangbanna Tropical Botanical Garden soil sample and identified as Bacillus megaterium. The strain’s volatiles had remarkable plant growth promotion activity in Arabidopsis thaliana plants; after 15 days treatment, the fresh weight of plants inoculated with XTBG34 was almost 2-fold compared with those inoculated with DH5α. Head space volatile compounds produced by XTBG34, trapped with headspace solid phase microextraction and identified by gas chromatography–mass spectrometry, included aldehydes, alkanes, ketones and aroma components. Of the 11 compounds assayed for plant growth promotion activity in divided Petri plates, only 2-pentylfuran increased plant growth. We have therefore identified a new plant growth promotion volatile of B. megaterium XTBG34, which deserves further study in the mechanisms of interaction between plant growth-promoting rhizobacteria and plants.

Potassium Balance and Soil Exchangeable Potassium Accumulation in the Intensive Vegetable Fields of China

Chen Shuo,Yan Zhengjuan,Li Zhifang,Chen Qing 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Analysis on Self-breakdown Statistics Properties for a Spark Switch

Mo, Chen,Guofu, Li,Qinxiao, Dong,Zhifang, Liu,Zhiyuan, Li 대한전기학회 2014 The Journal of International Council on Electrical Vol.4 No.2

According to the working characteristics of over-voltage protective device for series compensation, the principle and structure of spark switch were introduced in this paper briefly. Special test loop and HV fast switch-off device were designed to evaluate the performance of spark swich in trials. Test data and mathematic statistic results revealed that the self-breakdown probability of spark switch obeyed the normal distribution and the cumulative distribution of spark switch self-breakdown had been less affected by different enviroment temperature. The number of trials was restricted to the characteristics of insulated gas and the electrode surface state in the practical application. Reasonable choice of test number can keep estimation error at a relatively low level, particularly for parameter estimation by using small sample of self-breakdown voltage. The conclusion is instructive to the development and engineering application of spark switch for over-voltage protective equipment of series compensation.