Molecular characterization of bacterial endophytes from four Pinus species and their nematicidal activity against pine wood nematode

Hanhong Bae,Lakshmi Narayanan Ponpandian,Soon Ok Rim,Gnanendra Shanmugam,Buyng Su Hwang,Junheon Kim,Seon Keun Lee,Sang-Tae Seo,Sang-Hyun Koh 한국농약과학회 2018 한국농약과학회 학술발표대회 논문집 Vol.2018 No.10

Molecular characterization of bacterial endophytes from four Pinus species and their nematicidal activity against pine wood nematode

Hanhong Bae,Lakshmi Narayanan Ponpandian,Soon Ok Rim,Gnanendra Shanmugam,Junhyun Jeon,Buyng Su Hwang,Junheon Kim,Seon Keun Lee,Sang-Tae Seo,Sang-Hyun Koh 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.10

Pine trees are ecologically important in Korea. They are seriously imperiled by Pine wilt disease (PWD), by pine wood nematode (PWN, Bursaphelenchus xylophilus). Here, we isolated and characterized bacterial endophytes (BEs) from pine trees in Korea for biological control of PWN using BE metabolites. Using culture-dependent approach BE isolates were extracted from three tissues (needles, stems, and roots) of four pine species across 18 sampling sites in Korea. Bacterial isolates were characterized into 389 distinct isolates based on 16S rDNA sequencing. Ethyl acetate crude extracts (CEs) of bacterial liquid cultures were prepared using ethyl acetate and screened for nematicidal activity against PWN. BEs (1,622 isolates) were isolated; their taxonomic binning resulted in 215 operational taxonomic units (OTUs). Analysis of species richness and Shannon’s diversity of the three tissues revealed that BEs colonized the needles more than the stem and root tissues. Furthermore, based on nematicidal activity screening of 389 isolates, 44 BEs were identified, with two isolates exhibiting a significant inhibitory activity against PWN. Taken together, these data revealed numerous nematicidal BEs in pine trees, providing new insights that can serve as an effective and promising alternative approach to combat PWD.

Genomic Insights into Nematicidal Activity of a Bacterial Endophyte, Raoultella ornithinolytica MG against Pine Wilt Nematode

Shanmugam, Gnanendra,Dubey, Akanksha,Ponpandian, Lakshmi Narayanan,Rim, Soon Ok,Seo, Sang-Tae,Bae, Hanhong,Jeon, Junhyun The Korean Society of Plant Pathology 2018 Plant Pathology Journal Vol.34 No.3

Pine wilt disease, caused by the nematode Bursaphelenchus xylophilus, is one of the most devastating conifer diseases decimating several species of pine trees on a global scale. Here, we report the draft genome of Raoultella ornithinolytica MG, which is isolated from mountain-cultivated ginseng plant as an bacterial endophyte and shows nematicidal activity against B. xylophilus. Our analysis of R. ornithinolytica MG genome showed that it possesses many genes encoding potential nematicidal factors in addition to some secondary metabolite biosynthetic gene clusters that may contribute to the observed nematicidal activity of the strain. Furthermore, the genome was lacking key components of avermectin gene cluster, suggesting that nematicidal activity of the bacterium is not likely due to the famous anthelmintic agent of wide-spread use, avermectin. This genomic information of R. ornithinolytica will provide basis for identification and engineering of genes and their products toward control of pine wilt disease.

Genomic Insights into Nematicidal Activity of a Bacterial Endophyte, Raoultella ornithinolytica MG against Pine Wilt Nematode

Gnanendra Shanmugam,Akanksha Dubey,Lakshmi Narayanan Ponpandian,임순옥,서상태,배한홍,전준현 한국식물병리학회 2018 Plant Pathology Journal Vol.34 No.3

Pine wilt disease, caused by the nematode Bursaphelenchus xylophilus, is one of the most devastating conifer diseases decimating several species of pine trees on a global scale. Here, we report the draft genome of Raoultella ornithinolytica MG, which is isolated from mountain-cultivated ginseng plant as an bacterial endophyte and shows nematicidal activity against B. xylophilus. Our analysis of R. ornithinolytica MG genome showed that it possesses many genes encoding potential nematicidal factors in addition to some secondary metabolite biosynthetic gene clusters that may contribute to the observed nematicidal activity of the strain. Furthermore, the genome was lacking key components of avermectin gene cluster, suggesting that nematicidal activity of the bacterium is not likely due to the famous anthelmintic agent of wide-spread use, avermectin. This genomic information of R. ornithinolytica will provide basis for identification and engineering of genes and their products toward control of pine wilt disease.

Electrodeposition of WO₃ nanostructured thin films for electrochromic and H₂S gas sensor applications

Poongodi, S.,Kumar, Palaniswamy Suresh,Mangalaraj, D.,Ponpandian, N.,Meena, P.,Masuda, Yoshitake,Lee, Chongmu Elsevier 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.719 No.-

<P><B>Abstract</B></P> <P>In this work, Vertically oriented WO<SUB>3</SUB> nanoflakes array films was synthesized via the template free facile electrodeposition method at room temperature. WO<SUB>3</SUB> nanoflakes arrays was adopted as an effective cathode electrode material in the electrochemical devices structure. The WO<SUB>3</SUB> material exhibits superior electrochromic performance shows a larger optical modulation (68.89% at 550 nm), faster response time (t<SUB>b</SUB> = 1.93 s, t<SUB>c</SUB> = 2.87 s), a higher coloration efficiency of about 154.93 cm<SUP>2</SUP> C<SUP>−1</SUP> and with excellent cyclic stability over 2000 cycles without any degradation. Futhermore, WO<SUB>3</SUB> nanoflakes array film was used for the detection of H<SUB>2</SUB>S gas that showed excellent response. A considerable increase in porosity and high surface roughness could be conducive for such an excellent and superior electrochromic characteristic as well as gas sensing performances. These results indicates that fabricated WO<SUB>3</SUB> nanoflakes array film by a simple strategy holds a great promise for potential multifunctional applications such as smart windows, gas sensors and optical sensors.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhanced photocatalytic performance of novel self-assembled floral β-Ga2O3 nanorods

K. Girija,S. Thirumalairajan,Astam K. Patra,D. Mangalaraj,N. Ponpandian,C. Viswanathan 한국물리학회 2013 Current Applied Physics Vol.13 No.4

Self-assembled monoclinic phase of novel floral b-Ga2O3 nanorods were prepared using reflux condensation method by controlled precipitation of metal cations with urea. The structural and morphological properties were investigated by X-ray powder diffraction, Raman spectroscopy and Scanning electron microscope. Single-crystalline nanorods with size 100 nm involved in the selfassembly process to form flowery pattern have diameter w1 mm with surface area 40.8 m2/g confirmed from transmission electron microscope and BrunauereEmmetteTeller analysis. The band gap energy of 4.59 eV was evaluated from the UVevis diffuse reflectance spectrum and the photoluminescence spectrum displayed the characteristic luminescence and blue-light emission peaks. Further, the photocatalytic activity of novel b-Ga2O3 floral nanorods towards the photodegradation of Rhodamine B in aqueous solution under ultra violet light irradiation showed better photocatalytic activity than the commercial photocatalyst Degussa P25 TiO2.

Template-Free Growth of Novel Hydroxyapatite Nanorings: Formation Mechanism and Their Enhanced Functional Properties

Nathanael, A. Joseph,Hong, Sun Ig,Mangalaraj, D.,Ponpandian, N.,Chen, Pao Chi American Chemical Society 2012 Crystal Growth & Design Vol.12 No.7

<P>Template-free, single crystalline novel hydroxyapatite (HAp) nanorings with an inner diameter of 70 nm were grown by a combined high gravity and hydrothermal approach. Nanodisks were suggested to be formed by oriented aggregation and Ostwald ripening of mostly calcium pyrophosphate nanospheres prepared initially by the high gravity method with a stepwise increase of flow rate of phosphate solution. The prolonged hydrothermal treatment of nanodisks appeared to induce the nanoring formation via acid penetration along the dislocations in HAp nanodisks. The presence of edge dislocations in the central region of nanodisks was confirmed by high resolution transmission electron microscopy. The mechanical evaluation of high molecular weight polyethylene (HMWPE) composite with various shaped HAp nanocrystals and in vitro cellular analysis of HAp nanocrystals revealed that mechanical and bioactive performances improved with an increase of the specific surface area of HAp nanocrystals. The enhanced mechanical performance of HMWPE/HAp nanoring composite and the excellent cell viability for HAp nanorings are attributed to the superior interface bonding and cell activity, respectively, both of which are enhanced by the high specific surface area.</P><P>This work describes the template free growth mechanism and the enhanced properties of novel hydroxyapatite nanorings. Formation of nanodisk was explained by initial oriented aggregation and Ostwald ripening. Nanoring formation was suggested to be induced by acid penetration along the dislocations. Mechanical and in vitro analysis proved the enhanced functional properties of this novel structure.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cgdefu/2012/cgdefu.2012.12.issue-7/cg3003959/production/images/medium/cg-2012-003959_0001.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cg3003959'>ACS Electronic Supporting Info</A></P>

Self assembled V2O5 nanorods for gas sensors

A. Dhayal Raj,T. Pazhanivel,P. Suresh Kumar,D. Mangalaraj,D. Nataraj,N. Ponpandian 한국물리학회 2010 Current Applied Physics Vol.10 No.2

Hollow spheres of vanadium pentoxide made up of self assembled nanorods have been prepared successfully by solvothermal method. The calcinated samples of V2O5 nanorods exhibit orthorhombic structure as determined through XRD analysis. The nanorods are found to self assemble into hollow sphere like structures which can be clearly seen in SEM images. The diameter of the hollow spheres were around 2–3 ㎛, while the nanorods forming the micro spheres were with diameters in the range of 100–200 nm and are of few hundreds of nanometers in length. The change in the resistance of the V2O5 nanorod sensing element with respect to the test gas concentration was measured by noting down the resistance at each concentration for various time intervals. Sensitivity of the material linearly increased with different concentration of ethanol and ammonia. It is clearly seen that the V2O5 nanorods have more sensing response for ethanol when compared to that of ammonia.

Facile synthesis of monodispersed 3D hierarchical Fe₃O₄ nanostructures decorated r-GO as the negative electrodes for Li-ion batteries

Kumar, S. Rajesh,Kim, Jong Guk,Viswanathan, C.,Kim, Won Bae,Selvan, R. Kalai,Ponpandian, N. Elsevier 2018 Materials research bulletin Vol.97 No.-

<P><B>Abstract</B></P> <P>One-pot solvothermal process is adopted to develop, 3D hierarchical Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles supported 2D reduced graphene oxide sheets (Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO) as possible negative electrodes for lithium ion batteries. The synthesis parameters are optimized to prepare agglomeration-free Fe<SUB>3</SUB>O<SUB>4</SUB> nanostructures with uniform size and shape on r-GO. The field emission scanning electron microscopic (FESEM) image reveals that the 3D hierarchical Fe<SUB>3</SUB>O<SUB>4</SUB> nanostructures are uniformly decorated on r-GO. The physicochemical and functional properties of Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO are systematically investigated using various techniques. The fabricated Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO electrode delivers an initial discharge capacity of 1221mAhg<SUP>−1</SUP> at a current density of 100mAg<SUP>−1</SUP> and retains the specific capacity of 1560mAhg<SUP>−1</SUP> after 100 cycles. Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO significantly enhances cyclic performance, when compared with bare Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles due to the uniform distribution of Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles on the graphene sheet with the more number of electrochemically active sites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Monodispersed Fe<SUB>3</SUB>O<SUB>4</SUB> nanostructures with different shapes synthesized by solvothermal method. </LI> <LI> The fabricated Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO electrode delivers an initial discharge capacity of 1221mAhg<SUP>−1</SUP> at 100mAhg<SUP>−1</SUP>. </LI> <LI> Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO significantly enhances the cyclic stability and rate capability than bare Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>