Green synthesis of gold nanoparticles using extracellular metabolites of fish gut microbes and their antimicrobial properties.

In the present study, we synthesis nanoparticles using biosynthesis methods because of the eco-friendly approach. Gold nanoparticles were synthesized using extracellular metabolites of marine bacteria (Rastrelliger kanagurta, Selachimorpha sp., and Panna microdon). After the synthesis gold nanoparticles checked their antibacterial and antimycobacterial activities. Here we have few techniques that have been used for characterizing the gold nanoparticles followed by ultraviolet (UV)-visible spectrophotometer analysis, Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscopy (TEM). We observed the formation of gold nanoparticles using UV-Vis spectroscopy (UV-Vis). FT-IR spectroscopy results of the extracellular metabolites showed that different characteristic functional groups are responsible for the bioreduction of gold ions. In the recent years, we used zebrafish for an animal model to estimate nanoparticle toxicity and biocompatibility. We tested toxicity of the gold nanoparticle using the zebrafish larvae that are growing exponentially. Sample 1 showed a good antimicrobial activity, and sample 5 showed a good antimycobacterial activity. Based on the UV spectrophotometer, sample 1 is used for further studies. Color change and UV spectrum confirmed gold nanoparticles. Based on the TEM and SEM particles, size was measured and ranged between 80 and 45 nm, and most of the particles are spherical and are in rod shape. XRD result showed the gold nanoparticles with crystalline nature. Toxicity studies in the zebrafish larvae showed that 50 µg ml-1 showed less toxicity. Based on the studies, gold nanoparticle has good antibacterial and antimycobacterial activities. The present was concluded that gold nanoparticles have potential biocompatibility and less toxicity. Gold nanoparticles will be used as a drug molecule in pharmaceutical company and biomedicine application.

Complete genome sequencing of cucumber mosaic virus from black pepper revealed rare deletion in the methyltransferase domain of 1a gene.

The complete genome of cucumber mosaic virus (CMV) from black pepper was sequenced and compared with CMV isolates from subgroups I and II reported worldwide. Percent identity and phylogenetic analyses clearly indicated that the CMV isolate from black pepper (BP) belongs to subgroup IB. Sequence analyses also showed the presence of a rare deletion of nine nucleotides in the putative methyltransferase domain of 1a gene which was observed only in two more isolates of CMV among one hundred 1a gene sequences of CMV for which sequence information is available in the database. Interestingly this deletion is not present in the black pepper isolate of CMV from China (WN1) and from Indian long pepper that is closely related to black pepper. Percent identity analyses showed that the 3'untranslated region (UTR) of the three RNAs of the BP isolate were conserved with 91% identity whereas the 5'UTR of three RNAs showed 52-80% identity. The level of gene conservation among the subgroups was highest in coat protein and lowest in 2b. The values of nucleotide diversity studies were further consistent with the above data. The ratio of non-synonymous to the synonymous substitution of the five genes of three RNAs was in the order 1a > 2a > 2b > 3a > 3b and less than one for all the genes, indicating purifying selection. These clearly reflect that the protein encoded by RNA1 is highly tolerant to amino acid changes followed by that of RNA2 and, RNA3 is the least tolerant correlating to its functional importance.

Sequence diversity among badnavirus isolates infecting black pepper and related species in India.

The badnavirus, piper yellow mottle virus (PYMoV) is known to infect black pepper (Piper nigrum), betelvine (P. betle) and Indian long pepper (P. longum) in India and other parts of the world. Occurrence of PYMoV or other badnaviruses in other species of Piper and its variability is not reported so far. We have analysed sequence variability in the conserved putative reverse transcriptase (RT)/ribonuclease H (RNase H) coding region of the virus using specific badnavirus primers from 13 virus isolates of black pepper collected from different cultivars and regions and one isolate each from 23 other species of Piper. Of these, four species failed to produce expected amplicon while amplicon from four other species showed more similarities to plant sequences than to badnaviruses. Of the remaining, isolates from black pepper, P. argyrophyllum, P. attenuatum, P. barberi, P. betle, P. colubrinum, P. galeatum, P. longum, P. ornatum, P. sarmentosum and P. trichostachyon showed an identity of >85 % at the nucleotide and >90 % at the amino acid level with PYMoV indicating that they are isolates of PYMoV. On the other hand high sequence variability of 21-43 % at nucleotide and 17-46 % at amino acid level compared to PYMoV was found among isolates infecting P. bababudani, P. chaba, P. peepuloides, P. mullesua and P. thomsonii suggesting the presence of new badnaviruses. Phylogenetic analyses showed close clustering of all PYMoV isolates that were well separated from other known badnaviruses. This is the first report of occurrence of PYMoV in eight Piper spp and likely occurrence of four new species in five Piper spp.

Molecular characterization, immune responses and DNA protection activity of rock bream (Oplegnathus fasciatus), peroxiredoxin 6 (Prx6).

In this study, we describe the molecular characterization, immune responses of rock bream, Oplegnathus fasciatus peroxiredoxin 6 cDNA (RbPrx6) and DNA protection activity of its recombinant protein. The full-length cDNA sequence of RbPrx6 was identified after pyrosequencing of rock bream cDNA library. RbPrx6 consists of 663 bp open reading frame (ORF) that codes for a putative protein of 221 amino acids with predicted molecular mass of 27 kDa. It showed characteristic peroxiredoxin super-family domain similar to vertebrate Prx counterparts. In the pair-wise comparison, RbPrx6 showed the highest amino acid identity (92.8%) to Scophthalmus maximus Prx6. Real-time RT-PCR analysis revealed that constitutive expression of RbPrx6 transcripts in eleven tissues selected from un-challenged fish showing the highest level in liver. Synthetic polyinosinic:polycytidylic acid (poly I:C) and iridovirus containing supernatant, up-regulated the RbPrx6 mRNA in liver. Purified recombinant RbPrx6 protein was able to protect supercoiled plasmid DNA from damages that is induced by metal-catalyzed generation of reactive oxygen species. Our results suggest that RbPrx6 may play an important role in regulating oxidative stress by scavenging of ROS, involving immune reactions and minimizing the DNA damage in rock bream.

Surface antigenic profiling of stem cells from human omentum fat in comparison with subcutaneous fat and bone marrow.

Omentum fat derived stem cells have emerged as an alternative and accessible therapeutic tool in recent years in contrast to the existing persuasive sources of stem cells, bone marrow and subcutaneous adipose tissue. However, there has been a scanty citation on human omentum fat derived stem cells. Furthermore, identification of specific cell surface markers among aforesaid sources is still controversial. In lieu of this existing perplexity, the current research work aims at signifying omentum fat as a ground-breaking source of stem cells by surface antigenic profiling of stem cell population. In this study, we examined and compared the profiling of cell surface antigenic expressions of hematopoietic stem cells, mesenchymal stem cells, cell adhesion molecules and other unique markers such as ABCG2, ALDH and CD 117 in whole cell population of human omentum fat, subcutaneous fat and bone marrow. The phenotypic characterization through flowcytometry revealed the positive expressions of CD 34, CD 45, CD 133, HLADR, CD 90, CD 105, CD 73, CD 29, CD 13, CD 44, CD 54, CD 31, ALDH and CD 117 in all sources. The similarities between the phenotypic expressions of omentum fat derived stem cells to that of subcutaneous fat and bone marrow substantiates that identification of ultimate source for curative therapeutics is arduous to assess. Nevertheless, these results support the potential therapeutic application of omentum fat derived stem cells.

Self-assembly of Silver Nanoparticles and Multiwall Carbon Nanotubes on Decomposed GaAs Surfaces.

Atomic Force Microscopy complemented by Photoluminescence and Reflection High Energy Electron Diffraction has been used to study self-assembly of silver nanoparticles and multiwall carbon nanotubes on thermally decomposed GaAs (100) surfaces. It has been shown that the decomposition leads to the formation of arsenic plate-like structures. Multiwall carbon nanotubes spin coated on the decomposed surfaces were mostly found to occupy the depressions between the plates and formed boundaries. While direct casting of silver nanoparticles is found to induce microdroplets. Annealing at 300°C was observed to contract the microdroplets into combined structures consisting of silver spots surrounded by silver rings. Moreover, casting of colloidal suspension consists of multiwall carbon nanotubes and silver nanoparticles is observed to cause the formation of 2D compact islands. Depending on the multiwall carbon nanotubes diameter, GaAs/multiwall carbon nanotubes/silver system exhibited photoluminescence with varying strength. Such assembly provides a possible bottom up facile way of roughness controlled fabrication of plasmonic systems on GaAs surfaces.