Bioconversion of 1-adamantanol to 1,3-adamantanediol using Streptomyces sp. SA8 oxidation system

To efficiently produce 1,3-adamantanediol (1,3-ad(OH)₂) from 1-adamantanol (1-adOH), our stocks of culture strains and soil microorganisms were surveyed for hydroxylation activity towards 1-adOH. Among them, the soil actinomycete SA8 showing the highest hydroxylation activity was identified as Streptomyces sp. based on 16S ribosomal DNA sequence analysis. The reaction products were purified by silica gel column chromatography, and from NMR and MS analyses, they were identified as 1,3-ad(OH)₂ and 1,4-ad(OH)₂. Streptomyces sp. SA8 produced 5.9 g l^? 1 1,3-ad(OH)₂from 6.2 g l^? 1 1-adOH in culture broth after 120 h at 25 °C. Using resting cells, 2.3 g l^? 1 1,3-ad(OH)₂ was produced after 96 h of incubation at a 69% conversion rate. In both cases, 1,4-ad(OH)₂ was formed as a byproduct at a rate of about 15%. Strain SA8 also hydroxylated 2-adamantanol and 2-methyl-2-adamantanol.     

Polysulfide reduction using sulfate-reducing bacteria in a photocatalytic hydrogen generation system

A hydrogen generation process using photocatalytic reactions has been proposed. In this process, hydrogen sulfide is a source of hydrogen and is turned into polysulfide. In order to establish the cyclic operation of a photocatalytic hydrogen generation system, it is necessary to convert polysulfide back into hydrogen sulfide with a small energy input. This paper proposes the use of sulfate-reducing bacteria (SRB) for the regeneration of hydrogen sulfide. Batch cultivation of natural source SRB samples were carried out using a culture medium containing polysulfide as the only sulfur compound source. SRB produced hydrogen sulfide from several kinds of polysulfide sources, including a photocatalytic hydrogen generation-produces solution. Production lag phase and production rate of hydrogen sulfide were affected by initial polysulfide concentration. SRB activity was inhibited at high initial polysulfide concentrations. SRB enrichment culture T2, exhibited the highest hydrogen sulfide production rate, and was able to utilize several kinds of organic matter as the electron donor. The results suggest the possibility of using large biomass sources, such as sewage sludge and the raw garbage in a hydrogen generation system. We developed speculative estimates that an SRB based hydrogen generation system is feasible.     

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.     

Oxygen Self-Diffusion in Single-Crystal Y2O3

Self-diffusion coefficients of the oxygen ion in single-crystal Y₂O₃ were determined by the gas-solid isotope exchange technique. The results in the range 1100° to 1500°C are described by D=7.3 X 10^-6 exp [-19l(kJ/mol)/RT] cm²/s. Comparison of the results with those for oxides with the fluorite-type structure indicates that the regularly arranged vacant anion sites in the C-type structure do not contribute eflectively to oxygen ion diffusion .     

Polymers of α-substituted benzyl methacrylates as a new type of electron-beam resist

Summary Polymer of α-substituted benzyl methacrylate was found to be used as a new type of positive electron-beam resist, which forms methacrylic acid units in the polymer chain on the exposure to electron-beam and can be developed using alkaline solution as a developer. The sensitivity was dependent on the bulkiness of the ester group and the number of ?-hydrogen atoms in the ester group. The sensitivity and γ-value of atactic poly(α, α-dimethylbenzyl methacrylate) were improved by a factor of more than three over poly (methyl methacrylate).     

One Pot Cooking of Rice Grains for Preparation of Rice-Gel Samples Using a Small-Scale Viscosity Analyzer: Small-scale Rice-gel Preparation from Grains

Rice-gel prepared by the following three steps: rice grain cooking, shearing of the cooked rice, and cooling for gel formation, is expected as a novel food ingredient for modification of various food products such as bread and noodles. To meet the demand for high-throughput systems for research and developments on the new rice gels, herein we established a mini-cooking system for preparation of rice gel samples from grains using a small-scale viscosity analyzer (Rapid Visco Analyzer; RVA). Polished rice grains (4 g) were cooked with 22 mL of water in a canister, and the paddle equipped in the canister was rotated at 2,000 rpm for 30 min (80 °C was used as a representative) to shear the cooked rice. The sheared paste was cooled to 10 °C at 160 rpm, and the initial gelation property was evaluated by viscosity analysis within the RVA. Alternatively, the sheared paste was transferred to an acrylic mold and kept at 4 °C for 0, 1, 3, and 5 days for determination of the hardness with a compression test. Compressive forces required to penetrate 20 % thickness for three tested rice cultivars were measured, and the trend of the value shifts during preservation is similar to the corresponding trend obtained in 300-g grain scale laboratory tests, whereas the individual values were halved in the former. This small cooking method could offer a useful assay system for a rapid evaluation in the breeding programs and in the high-throughput screening of additives for the modification of properties.     

Lactic acid bacteria isolated from ethnic preserved meat products of the Western Himalayas

We used culture- and molecular-biology-based methods to investigate the diversity of lactic acid bacteria (LAB) in the ethnic chevon (goat) meat products chartayshya, jamma and arjia of the Western Himalayas. In six chartayshya, six jamma and four arjia samples, LAB were the predominant microbial component involved in the fermentation of these samples, and the total LAB population in arjia (7.8 ± 0.1 log cfu g⁻¹; mean ± SD) was significantly higher (P < 0.05) than in chartayshya (6.9 ± 0.1 log cfu g⁻¹) and jamma (7.5 ± 0.1 log cfu g⁻¹). We identified 53 LAB samples by 16S rRNA and phenylalanyl-tRNA synthase (pheS) genes sequencing. The LAB isolates were identified as Enterococcus durans, Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Leuconostoc citreum, Leuconostoc mesenteroides, Pediococcus pentosaceus, and Weissella cibaria. These results revealed that there is a high level of diversity of LAB in the Himalayan ethnic preserved meat products.     

Influence of different feeding systems on the growth performance and muscle development of Japanese Black steers

This study investigated the growth performance and gene expression for muscle development between grass hay-fed (GH) and concentrate-fed (CT) steers. Daily gain and energy intake during the fattening period of the GH group were lower than those of the CT group. Analysis of C/EBPα, PPARγ2, myosin heavy chain (MHC), and myostatin gene expressions was performed by real-time PCR. Expressions of C/EBPα and myostatin in semitendinosus and longissimus lumborum (LL) muscles were higher in the CT group than in the GH group at the end of fattening. In LL muscle, MHC expression at the end of fattening was greater in the GH group than in the CT group. These results suggest that regulation of adipogenesis and myogenesis by the expression of genes involved in muscle development might have occurred in the skeletal muscle of the GH group by the feeding of grass hay and/or because of the low energy intakes.     

Inhibitory effect of high concentrations of ferric ions on the activity of Acidithiobacillus ferrooxidans

The influence of high concentrations of ferric ions on the biochemical activity of Acidithiobacillus ferrooxidans was studied using intact cells. The specific oxidation rate of ferrous ions decreased with increasing ferric ion concentration. Lineweaver-Burk plots revealed typical competitive inhibition kinetics, because the slopes varied with the ferric ion concentration. A linear relationship between the slope and the square of the ferric ion concentration revealed that the iron-oxidizing enzyme system of A. ferrooxidans was competitively inhibited by about two molecules of ferric ion. The kinetic equation based on this inhibition model agreed with the experimental observation at a high ferric ion concentration where the bacterium is usually exposed in bioleaching and biooxidation plants.