<Emphasis Type="Italic">Luteimonas aestuarii</Emphasis> sp. nov., isolated from tidal flat sediment

A novel bacterium B9^T was isolated from tidal flat sediment. Its morphology, physiology, biochemical features, and 16S rRNA gene sequence were characterized. Colonies of this strain are yellow and the cells are Gram-negative, rod-shaped, and do not require NaCl for growth. The 16S rRNA gene sequence similarity indicated that strain B9^T is associated with the genus Lysobacter (≤ 97.2%), Xanthomonas (≤ 96.8%), Pseudomonas (≤ 96.7%), and Luteimonas (≤ 96.0%). However, within the phylogenetic tree, this novel strain shares a branching point with the species Luteimonas composti CC-YY255^T (96.0%). The DNA-DNA hybridization experiments showed a DNA-DNA homology of 23.0% between strain B9^T and Luteimonas mephitis B1953/27.1^T. The G+C content of genomic DNA of the type strain is 64.7 mol% (SD, 1.1). The predominant fatty acids are iso-C_11:0, iso-C_15:0, iso-C_16:0, iso-C_17:0, iso-C_17:0 ω9c, and iso-C_11:0 3-OH. Combined analysis of the 16S rRNA gene sequences, fatty acid profile, and results from physiological and biochemical tests indicated that there is genotypic and phenotypic differentiation of the isolate from other Luteimonas species. For these reasons, strain B9^T was proposed as a novel species, named Luteimonas aestuarii. The type strain of the new species is B9^T (= KCTC 22048^T, DSM 19680^T).     

Sulforaphane attenuates hepatic fibrosis via NF-E2-related factor 2-mediated inhibition of transforming growth factor-β/Smad signaling

Sulforaphane (SFN) is a dietary isothiocyanate that exerts chemopreventive effects via NF-E2-related factor 2 (Nrf2)-mediated induction of antioxidant/phase II enzymes, such as heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1). This work was undertaken to evaluate the effects of SFN on hepatic fibrosis and profibrotic transforming growth factor (TGF)-β/Smad signaling, which are closely associated with oxidative stress. SFN suppressed TGF-β-enhanced expression of α-smooth muscle actin (α-SMA), a marker of hepatic stellate cell (HSC) activation, and profibrogenic genes such as type I collagen, fibronectin, tissue inhibitor of matrix metalloproteinase (TIMP)-1, and plasminogen activator inhibitor (PAI)-1 in hTERT, an immortalized human HSC line. SFN inhibited TGF-β-stimulated activity of a PAI-1 promoter construct and (CAGA)(9) MLP-Luc, an artificial Smad3/4-specific reporter, in addition to reducing phosphorylation and nuclear translocation of Smad3. Nrf2 overexpression was sufficient to inhibit the TGF-β/Smad signaling and PAI-1 expression. Conversely, knockdown of Nrf2, but not inhibition of HO-1 or NQO1 activity, significantly abolished the inhibitory effect of SFN on (CAGA)(9) MLP-Luc activity. However, inhibition of NQO1 activity reversed repression of TGF-β-stimulated expression of type I collagen by SFN, suggesting the involvement of antioxidant activity of SFN in the suppression of Smad-independent fibrogenic gene expression. Finally, SFN treatment attenuated the development and progression of early stage hepatic fibrosis induced by bile duct ligation in mice, accompanied by reduced expression of type I collagen and α-SMA. Collectively, these results show that SFN elicits an antifibrotic effect on hepatic fibrosis through Nrf2-mediated inhibition of the TGF-β/Smad signaling and subsequent suppression of HSC activation and fibrogenic gene expression.     

Crystalline structure analysis of cellulose treated with sodium hydroxide and carbon dioxide by means of X-ray diffraction and FTIR spectroscopy

Crystalline structures of cellulose (named as Cell 1), NaOH-treated cellulose (Cell 2), and subsequent CO2-treated cellulose (Cell 2-C) were analyzed by wide-angle X-ray diffraction and FTIR spectroscopy. Transformation from cellulose I to cellulose II was observed by X-ray diffraction for Cell 2 treated with 15-20 wt% NaOH. Subsequent treatment with CO2 also transformed the Cell 2-C treated with 5-10 wt% NaOH. Many of the FTIR bands including 2901, 1431, 1282, 1236, 1202, 1165, 1032, and 897 cm(-1) were shifted to higher wave number (by 2-13 cm(-1)). However, the bands at 3352, 1373, and 983 cm(-1) were shifted to lower wave number (by 3-95 cm(-1)). In contrast to the bands at 1337, 1114, and 1058 cm(-1), the absorbances measured at 1263, 993, 897, and 668 cm(-1) were increased. The FTIR spectra of hydrogen-bonded OH stretching vibrations at around 3352 cm(-1) were resolved into three bands for cellulose I and four bands for cellulose II, assuming that all the vibration modes follow Gaussian distribution. The bands of 1 (3518 cm(-1)), 2 (3349 cm(-1)), and 3 (3195 cm(-1)) were related to the sum of valence vibration of an H-bonded OH group and an intramolecular hydrogen bond of 2-OH ...O-6, intramolecular hydrogen bond of 3-OH...O-5 and the intermolecular hydrogen bond of 6-O...HO-3', respectively. Compared with the bands of cellulose I, a new band of 4 (3115 cm(-1)) related to intermolecular hydrogen bond of 2-OH...O-2' and/or intermolecular hydrogen bond of 6-OH...O-2' in cellulose II appeared. The crystallinity index (CI) was obtained by X-ray diffraction [CI(XD)] and FTIR spectroscopy [CI(IR)]. Including absorbance ratios such as A1431,1419/A897,894 and A1263/A1202,1200, the CI(IR) was evaluated by the absorbance ratios using all the characteristic absorbances of cellulose. The CI(XD) was calculated by the method of Jayme and Knolle. In addition, X-ray diffraction curves, with and without amorphous halo correction, were resolved into portions of cellulose I and cellulose II lattice. From the ratio of the peak area, that is, peak area of cellulose I (or cellulose II)/total peak area, CI(XD) were divided into CI(XD-CI) for cellulose I and CI(XD-CII) for cellulose II. The correlation between CI(XD-CI) (or CI(XD-CII)) and CI(IR) was evaluated, and the bands at 2901 (2802), 1373 (1376), 897 (894), 1263, 668 cm(-1) were good for the internal standard (or denominator) of CI(IR), which increased the correlation coefficient. Both fraction of the absorbances showing peak shift were assigned as the alternate components of CI(IR). The crystallite size was decreased to constant value for Cell 2 treated at >or= 15 wt% NaOH. The crystallite size of Cell 2-C (cellulose II) was smaller than that of Cell 2 (cellulose I) treated at 5-10 wt% NaOH. But the crystallite size of Cell 2-C (cellulose II) was larger than that of Cell 2 (cellulose II) treated at 15-20 wt% NaOH.     

Isolation and functional analysis of a 24-residue linear alpha-helical antimicrobial peptide from Korean blackish cicada, Cryptotympana dubia (Homoptera)

A new antimicrobial peptide, cryptonin, was isolated and characterized from the adult Korean blackish cicada, Cryptotympana dubia. It consists of 24 amino acid residues and has a molecular weight of 2,704 Da on mass spectroscopy. The predicted alpha-helical structure analysis and increased helix percent in 40% trifloroethanol of cryptonin suggests that it belongs to the typical linear alpha-helix forming peptide. Binding of the biotin-labeled cryptonin at the surface of E. coli cells and increased influx of propidium iodide in E. coli after cryptonin treatment indicates that it kills microbial cells by binding bacterial cell surfaces and disrupting the cell permeability. Cryptonin showed strong antibacterial (MIC 1.56-25 microg/ml) and antifungal (MIC 3.12-50 microg/ml) activities against tested bacteria and fungi including two antibiotic-resistant bacterial strains; methicilin-resistant S. aureus and vancomycin-resistant Enterococci (MIC 25 microg/ml, each).     

Analysis of oligomeric fermentation substrates and products by high pressure size exclusion chromatography

Summary Commercially available maltodextrins were subjected to high pressure size exclusion chromatography (HPSEC) on Toyo Soda G 2000 PW columns with water as the mobile phase. The elution profiles of these samples will allow researchers to select the correct maltodextrin for growth studies requiring specific dextrin oligomers. Characterization of the chromatography system with standards of known molecular weight allows estimation of the weight average molecular weight of polydisperse dextrins. The enzymatic hydrolysis of dextrin by bacterial-amylase and fungal glucoamylase was also monitored by HPSEC.     

Determination of anti-Aspergillus activity of antifungal agents based on the dynamic growth rate of a single hypha

The dynamic growth rate of a single hypha of Aspergillus niger was analysed using an automatic system. A colony of A. niger was in contact with saline, saline containing an antifungal agent, and flushing saline, in sequence. The growth rate of a test hypha selected arbitrarily from the colony responded dynamically to the antifungal agent. The minimum concentration that caused the complete inhibition of hyphal growth was defined as the minimum inhibitory concentration (MIC). The MIC values obtained were compared with those determined by conventional methods based on increasing rate of colony diameter or dry matter weight.     

Thionine increases electricity generation from microbial fuel cell using Saccharomyces cerevisiae and exoelectrogenic mixed culture

Microbial fuel cells (MFCs) have been shown to be capable of clean energy production through the oxidation of biodegradable organic waste using various bacterial species as biocatalysts. In this study we found Saccharomyces cerevisiae, previously known electrochemcially inactive or less active species, can be acclimated with an electron mediator thionine for electrogenic biofilm formation in MFC, and electricity production is improved with facilitation of electron transfer. Power generation of MFC was also significantly increased by thionine with both aerated and non-aerated cathode. With electrochemically active biofilm enriched with swine wastewater, MFC power increased more significantly by addition of thionine. The optimum mediator concentration was 500 mM of thionine with S. cerevisae in MFC with the maximum voltage and current generation in the microbial fuel cell were 420 mV and 700 mA/m(2), respectively. Cyclic voltametry shows that thionine improves oxidizing and reducing capability in both pure culture and acclimated biofilm as compared to non-mediated cell. The results obtained indicated that thionine has great potential to enhance power generation from unmediated yeast or electrochemically active biofilm in MFC.     

Precise recapitulation of methylation change in early cloned embryos

Change of DNA methylation during preimplantation development is very dynamic, which brings this term to the most attractive experimental target for measuring the capability of cloned embryo to reprogram its somatic genome. However, one weak point is that the preimplantation stage carries little information on genomic sequences showing a site-specific re-methylation after global demethylation; these sequences, if any, may serve as an advanced subject to test how exactly the reprogramming/programming process is recapitulated in early cloned embryos. Here, we report a unique DNA methylation change occurring at bovine neuropeptide galanin gene sequence. The galanin gene sequence in early bovine embryos derived by in vitro fertilization (IVF) maintained a undermethylated status till the morula stage. By the blastocyst, certain CpG sites became methylated specifically, which may be an epigenetic sign for the galanin gene to start a differentiation programme. The same sequence was moderately methylated in somatic donor cell and, after transplanted into an enucleated oocyte by nuclear transfer (NT), came rapidly demethylated to a completion, and then, at the blastocyst stage, re-methylated at exactly the same CpG sites, as observed so in normal blastocysts. The precise recapitulation of normal methylation reprogramming and programming at the galanin gene sequence in bovine cloned embryos gives a cue for the potential of cloned embryo to superintend the epigenetic states of foreign genome, even after global demethylation.     

Neural interface with a silicon neural probe in the advancement of microtechnology

In this paper we describe the status of a silicon-based microelectrode for neural recording and an advanced neural interface. We have developed a silicon neural probe, using a combination of plasma and wet etching techniques. This process enables the probe thickness to be controlled precisely. To enhance the CMOS compatibility in the fabrication process, we investigated the feasibility of the site material of the doped polycrystalline silicon with small grains of around 50 nm in size. This silicon electrode demonstrated a favorable performance with respect to impedance spectra, surface topography and acute neural recording. These results showed that the silicon neural probe can be used as an advanced microelectrode for neurological applications.