A comparative study of ethanol production by Issatchenkia orientalis strains under stress conditions

The ability of 13 strains of multi-stress-tolerant Issatchenkia orientalis yeast to produce ethanol was examined under different stress conditions, including conditions of elevated H₂SO₄ and Na₂SO₄ concentrations and increased heat. The MF-121 strain produced a significant amount of ethanol after the incubation in acidic media containing high concentrations of salt, e.g., 50 g/l Na₂SO₄ at pH 2.0, or at high temperatures, e.g., 43°C, when compared with other strains.     

Evaluation of drug toxicity with hepatocytes cultured in a micro-space cell culture system

A micro-space cell culture system was recently developed in which cells such as hepatocytes can be cultured and formed into a multicellular three-dimensional (3D) architecture. In this study, we assessed the performance of HepG2 cells cultured in this micro-space cell culture system in a drug toxicity test, and evaluated the effects of micro-space culture on their hepatocyte-specific functions. The micro-space cell culture facilitated the formation of 3D HepG2 cell architecture. HepG2 cells cultured in a micro-space culture plate exhibited increased albumin secretion and enhanced mRNA expression levels of cytochrome P450 (CYP) enzyme compared to those cultured in a monolayer culture. When the cells were exposed to acetaminophen, a hepatotoxic drug, the damage to the HepG2 cells grown in micro-space culture was greater than the damage to the HepG2 cells grown in monolayer culture. In addition, human primary hepatocytes grown in micro-space culture also exhibited increased albumin secretion, enhanced CYP mRNA expression levels and increased sensitivity to acetaminophen compared to those grown in monolayer culture. These results suggest that this micro-space culture method enhances the hepatocyte-specific functions of hepatocytes, including drug-metabolizing enzyme activities, making hepatocytes grown in the micro-space culture system a useful tool for evaluating drug toxicity in vitro.     

Physical properties of Mo6−xRuxTe8 and Mo6Te8−xSx

A series of the Chevrel phases, Mo_6−xRu_xTe₈ and Mo₆Te_8−xS_x (x=0, 1, 2), has been prepared and the various physical properties, such as the elastic modulus, Debye temperature, and electrical resistivity, have been evaluated. The relationships between several properties of the compounds have also been studied. Young’s modulus and Debye temperature of Mo_6−xRu_xTe₈ and Mo₆Te_8−xS_x increase with increasing x value. The relationship between the Vickers hardness and Young’s modulus shows ceramic characteristics for Mo_6−xRu_xTe₈, while they show glass-like characteristics for Mo₆Te_8−xS_x. The electrical resistivities of Mo_6−xRu_xTe₈ and Mo₆Te_8−xS_x increase with increasing x value.     

Determination of unprocessed genetically modified soybean in foods using simplex and duplex real-time PCR with an internal standard

We developed a method using an internal standard to determine the amount of unprocessed genetically modified organisms (GMO) in foods as GMO weight per weight of total food (w/w_tf) using real-time PCR. Food samples were spiked with an internal standard, a ColE1 plasmid, and DNA was extracted from the samples using a silica membrane-type kit and analysed using real-time PCR. The relationship between the GMO amount and the copy number ratio of the transgene to ColE1 in 0.1–5% w/w_tf GM soybean powders was found to have a correlation coefficient ( r ) of 0.97. GMO was quantified in food samples spiked with GM soybean (final amount 0.5% w/w_tf GMO). The average GMO amount ranged from 0.35% to 0.63% w/w_tf. The results show that our method should be useful for quantifying unprocessed GMO in foods. We also developed a duplex assay, which is simpler and more accurate than the simplex assay.     

Interfacial sol–gel processing for preparation of porous titania particles using a piezoelectric inkjet nozzle

The aim of the present work is to apply the liquid–liquid interfacial crystallization using a piezoelectric inkjet nozzle to the sol–gel processing. The instillation process was compared with the batch process to elucidate the effectiveness of the inkjet technique on the liquid–liquid interfacial sol–gel processing. The effect of frequency and water concentration in titanium tetraisopoxide (TTIP) solution on titania particle properties was investigated for sol–gel processing with a piezoelectric inkjet nozzle. Titania particles produced by each process were calcined at 500 °C. The crystal structure, morphology, pore size distribution and specific surface area of titania particles were evaluated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen physisorption measurement. The photocatalytic activity of titania particles was evaluated by the photodegradation of methylene blue solution under UVC light irradiation.     

Neuron Membrane Trafficking and Protein Kinases Involved in Autism and ADHD

A brain-enriched multi-domain scaffolding protein, neurobeachin has been identified as a candidate gene for autism patients. Mutations in the synaptic adhesion protein cell adhesion molecule 1 (CADM1) are also associated with autism spectrum disorder, a neurodevelopmental disorder of uncertain molecular origin. Potential roles of neurobeachin and CADM1 have been suggested to a function of vesicle transport in endosomal trafficking. It seems that protein kinase B (AKT) and cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) have key roles in the neuron membrane trafficking involved in the pathogenesis of autism. Attention deficit hyperactivity disorder (ADHD) is documented to dopaminergic insufficiencies, which is attributed to synaptic dysfunction of dopamine transporter (DAT). AKT is also essential for the DAT cell-surface redistribution. In the present paper, we summarize and discuss the importance of several protein kinases that regulate the membrane trafficking involved in autism and ADHD, suggesting new targets for therapeutic intervention.     

Protease susceptibility of beta-lactoglobulin adsorbed on stainless steel surface as evidence of contribution of its specific segment to adsorption

beta-Lactoglobulin (beta-Lg) is a major constituent of fouling deposits in the dairy industry. To determine the interaction between beta-Lg and stainless steel surfaces, beta-Lg irreversibly adsorbed on stainless steel particles was subjected to lysyl endopeptidase treatment and the course of fragmentation was compared with that observed for beta-Lg in solution. The results showed a distinct difference between the courses of fragmentation: a fragment (residues 102-135) was liberated readily from beta-Lg in solution but scarcely from beta-Lg irreversibly adsorbed on stainless steel particles. This result strongly suggests that residues 102-135 include a segment primarily responsible for the interaction of beta-Lg with stainless steel surfaces. This supports our previous results [Sakiyama et al., J. Biosci. Bioeng., 88, 536-541 (1999)] that showed that residues 125-135 of beta-Lg have a strong affinity toward stainless steel surfaces and probably a major contribution to the adsorption of beta-Lg.