Direct ethanol production from barley beta-glucan by sake yeast displaying Aspergillus oryzae beta-glucosidase and endoglucanase

Three beta-glucosidase- and two endoglucanase-encoding genes were cloned from Aspergillus oryzae, and their gene products were displayed on the cell surface of the sake yeast, Saccharomyces cerevisiae GRI-117-UK. GRI-117-UK/pUDB7 displaying beta-glucosidase AO090009000356 showed the highest activity against various substrates and efficiently produced ethanol from cellobiose. On the other hand, GRI-117-UK/pUDCB displaying endoglucanase AO090010000314 efficiently degraded barley beta-glucan to glucose and smaller cellooligosaccharides. GRI-117-UK/pUDB7CB codisplaying both beta-glucosidase AO090009000356 and endoglucanase AO090010000314 was constructed. When direct ethanol fermentation from 20 g/l barley beta-glucan as a model substrate was performed with the codisplaying strain, the ethanol concentration reached 7.94 g/l after 24 h of fermentation. The conversion ratio of ethanol from beta-glucan was 69.6% of the theoretical ethanol concentration produced from 20 g/l barley beta-glucan. These results showed that sake yeast displaying A. oryzae cellulolytic enzymes can be used to produce ethanol from cellulosic materials. Our constructs have higher ethanol production potential than the laboratory constructs previously reported.     

Preparation of surfactant-free vinyl polymers by conventional emulsion polymerization using hydrolysable emulsifiers

Emulsion polymerizations of several vinyl monomers, styrene, methyl methacrylate, butyl methacrylate, butyl acrylate, and vinyl acetate, in water using alkali–hydrolysable cationic surfactants with a betaine ester group (1-alkoxycarbonylmethyl)trimethylammonium chlorides, as emulsifiers were carried out and properties of the resulting latices and the polymers recovered by hydrolysis and salting out were investigated. There were little influences of the surfactants and monomers used here on the polymerizations, forming stable and monodisperse latices with a mean diameter of ca. 70 nm and giving a high molecular weight of polymers at high yields. All polymers were precipitated and recovered by adding a small amount of sodium hydroxide into the latex solutions contained little amount of ionic species. Solvent-cast films of the polymers were found to have surfaces as hydrophobic as those for the corresponding pure polymers prepared by bulk polymerization.     

Osteoclast differentiation at growth plate cartilage-trabecular bone junction in newborn rat femur

Using 3-day-old newborn rats, we examined the differentiation processes of osteoclasts associated with the destruction of the femoral growth plate cartilage and primary trabecular bone. In the growth plate cartilage, thin mineralized areas were detected solely in the longitudinal septal cartilage matrix in the hypertrophic zone, but the transverse septal cartilage matrix between adjacent chondrocytic lacunae within a row of chondrocytes remained unmineralized. The longitudinal septal cartilage between adjacent rows of chondrocytes appeared to persist, forming the walls of opened lacunar canals. Consistent with the removal of the transverse septal cartilage matrix, the longitudinal canals of opened chondrocytic lacunae were deeply invaded by capillary vessels, mononuclear cells and multinucleated pre-osteoclasts lacking a ruffled border. CD34-positive endothelial cells of capillary vessels deeply penetrated into the transverse septal cartilage matrix facing the medullary cavity and the opened chondrocytic lacunae. ED1-positive monocytes/macrophages were distributed at the chondro-osseous junction, but they were distant from the erosive front of the transverse septa. Tartrate-resistant acid phosphatase-positive multinucleated pre-osteoclasts lacking a ruffled border and differentiated osteoclasts with a ruffled border were localized mainly at two locations: the chondro-osseous junction and the growth front of primary bone trabeculae. Osteoclasts were located on the type-I collagen-positive bone trabeculae close to the growth plate, but they appeared to be distant from the type-II collagen-positive cartilage matrix. Even within opened chondrocytic lacunae, when osteoclasts were distant from the cartilage and bone matrix, they lacked polarized cytoplasmic organization and a ruffled border. The osteoclasts located in the remaining septal cartilage also exhibited neither a ruffled border nor a clear zone. Osteoclasts with a prominent ruffled border and clear zone were located in bone matrix covering the remaining septal cartilage. These results suggest that osteoclasts require hydroxyapatite crystals and bone matrix constituents for ruffled border formation and are not involved in resorption of the unmineralized transverse and mineralized longitudinal septal cartilage without covering bone matrix at the chondro-osseous junction.     

Porcine enamel matrix derivative enhances the formation of reparative dentine and dentine bridges during wound healing of amputated rat molars

We examined the biological effects of porcine enamel matrix derivative (EMD; Emdogain) on the formation of reparative dentine and dentine bridges in rat molars after pulp amputation. The pulp chambers of upper molars of Wistar rats were perforated and the amputated pulp surfaces were directly capped with either EMD or its carrier propylene glycol alginate (PGA) as control. The cavities were then restored with glass-ionomer cement. On post-amputation days 4-30, the dissected maxillae were examined by light and electron microscopy. In PGA-capped pulp, reparative dentine had been formed over the dentine walls under the prepared cavity on day 7 post-amputation and its thickness extended until day 30. On day 30, as well as reparative dentine formation, diffuse calcification had occurred beneath the amputated wound surfaces. Dentine bridge formation under the amputated coronal pulp surface was observed in 18.2% of amputated pulp on day 30. In EMD-capped pulp, reparative dentine had already been formed by odontoblast-like cells over the dentine walls, already on day 4 post-amputation, and its thickness extended until day 30. The Ca and P weight % and Ca/P ratio of reparative dentine matrix were similar to those of pre-existing dentine matrix, and these values were not different between PGA and EMD-capped pulp. Dentine bridge formation was observed in 27.3% of EMD-capped pulp on day 30. Our results suggest that EMD enhances the formation of both reparative dentine and dentine bridges during wound healing of amputated rat molar pulp.     

40 Gbit/s return-to-zero transmission over 500 km of standard fibreusing chirped fibre Bragg gratings with small group delay ripples

A 40 Gbit/s return-to-zero transmission has been successfully achieved over 500 km using standard fibres (non-dispersion shifted fibre, singlemode fibre) and chirped fibre Bragg gratings (CFBG). CFBGs were fabricated with small group delay ripples, and error free transmission (BER <1×10^-12) was achieved using these CFBGs for dispersion compensation     

SUPPRESSION OF α-ACETOLACTATE FORMATION IN BREWING WITH IMMOBILIZED YEAST

Immobilized yeast cells extensively produced the diacetyl precursor, α-acetolactate, during alcohol fermentation. The activity of acetohydroxy acid synthetase, which is responsible for the formation of α-acetolactate from pyruvic acid, was high in cell-free extracts of immobilized yeast cells compared with that of free yeast cells. It was suggested that the expression of AHA synthase of immobilized yeast cells was increased during growth in the carrier as compared with free yeast cells. When the initial immobilizing yeast cell concentration was changed from 1.0 × 10⁶ cells/ml to 1.0 × 10⁹ cells/ml, production of α-acetolactate was reduced from 0.94 mg/l to 0.30 mg/l. Furthermore, during continuous fermentation for 10 d, the concentration of α-acetolactate in beer was 0.30 mg/l.     

A high fill factor and progressive scan PtSi Schottky-barrier IR-CCD image sensor using new wiring technology

A back surface illuminated 130/spl times/130 pixel PtSi Schottky-barrier (SB) IR-CCD image sensor has been developed by using new wiring technology, referred to as CLOSE Wiring, CLOSE Wiring, designed to effectively utilize the space over the SB photodiodes, brings about flexibility in clock line designing, high fill factor, and large charge handling capability in a vertical CCD (VCCD). This image sensor uses a progressive scanned interline-scheme, and has a 64.4% fill factor in a 30 /spl mu/m/spl times/30 /spl mu/m pixel, a 3.9 mm/spl times/3.9 mm image area, and a 5.5 mm/spl times/5.5 mm chip size. The charge handling capability for the 3.3 /spl mu/m wide VCCD achieves 9.8/spl times/10/sup 5/ electrons, The noise equivalent temperature difference obtained was 0.099 K for operation at 120 frames/sec with a 50 mm f/1.3 lens.<>     

Breeding of high malate‐producing diploid sake yeast with a homozygous mutation in the VID24 gene

Malate is an important taste component of sake (a Japanese alcoholic beverage) that is produced by the yeast Saccharomyces cerevisiae during alcoholic fermentation. A variety of methods for generating high malate‐producing yeast strains have been developed to date. We recently reported that a high malate‐producing strain was isolated as a mutant sensitive to dimethyl succinate (DMS), and that a mutation in the vacuolar import and degradation protein (VID) 24 gene was responsible for high malate productivity and DMS sensitivity. In this work, the relationships between heterozygous and homozygous mutants of VID24 and malate productivity in diploid sake yeast were examined and a method was developed for breeding a higher malate‐producing strain. First a diploid yeast was generated with a homozygous VID24 mutation by genetic engineering. The homozygous integrants produced more malate during sake brewing and grew more slowly in DMS medium than wild‐type and heterozygous integrants. Thus, the genotype of the VID24 mutation influenced the level of malate production and sensitivity to DMS in diploid yeast. Then a homozygous mutant from a heterozygous mutant was obtained without genetic engineering by ultraviolet irradiation and culturing in DMS with nystatin enrichment. The non‐genetically modified sake yeast with a homozygous VID24 mutation exhibited a higher level of malate productivity than the parent heterozygous mutant strain. These findings provide a basis for controlling malate production in yeast, and thereby regulating malate levels in sake. Copyright © 2016 The Institute of Brewing & Distilling     

Effect of Si on the oxidation reaction of α-Ti(0 0 0 1) surface: ab initio molecular dynamics study

Abstract

We present our ab initio molecular dynamics (MD) study of the effect of Si on the oxidation of α-Ti(0?0?0?1) surfaces. We varied the Si concentration in the first layer of the surface from 0 to 25 at.% and the oxygen coverage (θ) on the surface was varied up to 1 monolayer (ML). The MD was performed at 300, 600 and 973 K. For θ = 0.5 ML, oxygen penetration into the slab was not observed after 16 ps of MD at 973 K while for θ > 0.5 ML, oxygen penetration into the Ti slab was observed even at 300 K. From Bader charge analysis, we confirmed the formation of the oxide layer on the surface of the Ti slab. At higher temperatures, the Si atoms diffused from the first layer to the interior of the slab, while the Ti atoms moved from second layer to the first layer. The pair correlation function shows the formation of a disordered Ti-O network during the initial stage of oxidation. Si was found to have a strong influence on the penetration of oxygen in the Ti slab at high temperatures.