Enzymatic hydrolyzing performance of Acremonium cellulolyticus and Trichoderma reesei against three lignocellulosic materials

<p>Abstract</p> <p>Background</p> <p>Bioethanol isolated from lignocellulosic biomass represents one of the most promising renewable and carbon neutral alternative liquid fuel sources. Enzymatic saccharification using cellulase has proven to be a useful method in the production of bioethanol. The filamentous fungi <it>Acremonium cellulolyticus </it>and <it>Trichoderma reesei </it>are known to be potential cellulase producers. In this study, we aimed to reveal the advantages and disadvantages of the cellulase enzymes derived from these fungi.</p> <p>Results</p> <p>We compared <it>A. cellulolyticus </it>and <it>T. reesei </it>cellulase activity against the three lignocellulosic materials: eucalyptus, Douglas fir and rice straw. Saccharification analysis using the supernatant from each culture demonstrated that the enzyme mixture derived from <it>A. cellulolyticus </it>exhibited 2-fold and 16-fold increases in Filter Paper enzyme and β-glucosidase specific activities, respectively, compared with that derived from <it>T. reesei</it>. In addition, culture supernatant from <it>A. cellulolyticus </it>produced glucose more rapidly from the lignocellulosic materials. Meanwhile, culture supernatant derived from <it>T. reesei </it>exhibited a 2-fold higher xylan-hydrolyzing activity and produced more xylose from eucalyptus (72% yield) and rice straw (43% yield). Although the commercial enzymes Acremonium cellulase (derived from <it>A. cellulolyticus</it>, Meiji Seika Co.) demonstrated a slightly lower cellulase specific activity than Accellerase 1000 (derived from <it>T. reesei</it>, Genencor), the glucose yield (over 65%) from lignocellulosic materials by Acremonium cellulase was higher than that of Accellerase 1000 (less than 60%). In addition, the mannan-hydrolyzing activity of Acremonium cellulase was 16-fold higher than that of Accellerase 1000, and the conversion of mannan to mannobiose and mannose by Acremonium cellulase was more efficient.</p> <p>Conclusion</p> <p>We investigated the hydrolysis of lignocellulosic materials by cellulase derived from two types of filamentous fungi. We found that glucan-hydrolyzing activity of the culture supernatant from <it>A. cellulolyticus </it>was superior to that from <it>T. reesei</it>, while the xylan-hydrolyzing activity was superior for the cellulase from <it>T. reesei</it>. Moreover, Acremonium cellulase exhibited a greater glucan and mannan-hydrolyzing activity than Accellerase 1000.</p

Widely Extended [OIII] 88 um Line Emission around the 30 Doradus Region Revealed with AKARI FIS-FTS

We present the distribution map of the far-infrared [OIII] 88um line emission around the 30 Doradus (30 Dor) region in the Large Magellanic Cloud obtained with the Fourier Transform Spectrometer of the Far-Infrared Surveyor onboard AKARI. The map reveals that the [OIII] emission is widely distributed by more than 10' around the super star cluster R136, implying that the 30 Dor region is affluent with interstellar radiation field hard enough to ionize O^{2+}. The observed [OIII] line intensities are as high as (1-2) x 10^{-6} W m^{-2} sr^{-1} on the peripheral regions 4'-5' away from the center of 30 Dor, which requires gas densities of 60-100 cm^{-3}. However the observed size of the distribution of the [OIII] emission is too large to be explained by massive stars in the 30 Dor region enshrouded by clouds with the constant gas density of 10^2 cm^{-3}. Therefore the surrounding structure is likely to be highly clumpy. We also find a global correlation between the [OIII] and the far-infrared continuum emission, suggesting that the gas and dust are well mixed in the highly-ionized region where the dust survives in clumpy dense clouds shielded from the energetic photons.Comment: 17 pages, 9 figures, accepted for publication in Publications of the Astronomical Society of Japan (PASJ

Dynamical exciton condensates in biased electron-hole bilayers

Bilayer materials may support interlayer excitons comprised of electrons in one layer and holes in the other. In experiments, a non-zero exciton density is typically sustained by a bias chemical potential, implemented either by optical pumping or by electrical contacts connected to the two layers. We show that if charge can tunnel between the layers, the chemical potential bias means that an exciton condensate is in the dynamical regime of ac Josephson effect. It has physical consequences such as tunneling currents and the ability to tune a condensate from bright (emitting coherent photons) to dark by experimental controlling knobs. If the system is placed in an optical cavity, coupling with cavity photons favors different dynamical states depending on the bias, realizing superradiant phases.Comment: 5 pages, 3 figure

Spin, charge and η\eta-spin separation in one-dimensional photo-doped Mott insulators

We show that effectively cold metastable states in one-dimensional photo-doped Mott insulators described by the extended Hubbard model exhibit spin, charge and $\eta$-spin separation. Namely, their wave functions in the large on-site Coulomb interaction limit can be expressed as $|\Psi\rangle =|\Psi_{\rm charge}\rangle|\Psi_{\rm spin}\rangle |\Psi_{\rm \eta-spin}\rangle$, which is analogous to the Ogata-Shiba states of the doped Hubbard model in equilibrium. Here $\eta$-spin represents the type of the photo-generated pseudeparticles (doublon or holon). $|\Psi_{\rm charge}\rangle$ is determined by spinless free fermions, $|\Psi_{\rm spin}\rangle$ by the isotropic Heisenberg model in the squeezed spin space, and $|\Psi_{\rm \eta-spin}\rangle$ by the XXZ model in the squeezed $\eta$-spin space. In particular, the metastable $\eta$-pairing and charge-density-wave (CDW) states correspond to the gapless and gapful states of the XXZ model. The specific form of the wave function allows us to accurately determine the exponents of correlation functions. The form also suggests that the central charge of the $\eta$-pairing state is 3 and that of the CDW phase is 2, which we numerically confirm. Our study provides analytic and intuitive insights into the correlations between active degrees of freedom in photo-doped strongly correlated systems.Comment: 6 pages, 4 figures + 13 pages, 2 figure

Suzaku Spectroscopy of an X-Ray Reflection Nebula and a New Supernova Remnant Candidate in the Sgr B1 Region

We made a 100 ks observation of the Sagittarius (Sgr) B1 region at (l, b) = (0.5, -0.1) near to the Galactic center (GC) with the Suzaku/XIS. Emission lines of S XV, Fe I, Fe XXV, and Fe XXVI were clearly detected in the spectrum. We found that the Fe XXV and Fe XXVI line emissions smoothly distribute over the Sgr B1 and B2 regions connecting from the GC. This result suggests that the GC hot plasma extends at least up to the Sgr B region with a constant temperature. There are two diffuse X-ray sources in the observed region. One of the two (G0.42-0.04) is newly discovered, and exhibits a strong S XV Ka emission line, suggesting a candidate for a supernova remnant located in the GC region. The other one (M0.51-0.10), having a prominent Fe I Ka emission line and a strongly absorbed continuum, is likely to be an X-ray reflection nebula. There is no near source bright enough to irradiate M0.51-0.10. However, the Fe I Ka emission can be explained if Sgr A* was ~ 10^6 times brighter 300 years ago, the light travel time for 100 pc to M0.51-0.10, than it is at present.Comment: 10 pages, 10 figure

Brain Alterations and Mini-Mental State Examination in Patients with Progressive Supranuclear Palsy: Voxel-Based Investigations Using 18F-Fluorodeoxyglucose Positron Emission Tomography and Magnetic Resonance Imaging

Background/Aims: The aim of this study was to compare differences in morphological and functional changes in brain regions in individual patients with progressive supranuclear palsy (PSP) and correlate their Mini-Mental State Examination (MMSE) score with anatomy and function using magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). Methods: Sixteen PSP patients and 20 age-matched healthy volunteers underwent FDG-PET and 3-dimensional MRI. Gray matter, white matter and metabolic activity were compared between patients and normal controls. In addition, possible correlations between the MMSE score and brain function/anatomy were examined. Results: The PSP group had reduced cerebral glucose metabolism, and lower gray and white matter volumes in the frontal lobes and midbrain compared with normal controls. In PSP subjects, the metabolic changes observed in the PET scans were greater than the loss in gray and white matter observed in the MRI scans. The MMSE scores were positively correlated with volume and FDG uptake in the frontal lobe. Conclusion: FDG-PET is a more effective tool in the diagnosis of PSP than MRI. Atrophy and hypometabolism in the frontal lobe are as important as in the basal midbrain for differentiating PSP patients who primarily exhibit cognitive dysfunction from normal controls

友人関係における"キャラ"の受け止め方と心理的適応:—中学生と大学生の比較—

　本研究では, 現代青年に顕著なキャラを介した友人関係について, 中学生と大学生の比較から検討が行われた。本研究の目的は, キャラの有無による心理的適応の相違に加えて, キャラの受け止め方とキャラ行動が心理的適応に及ぼす影響を明らかにすることであった。中学生396名と大学生244名に質問紙調査を行った。分析の結果, 大学生は中学生よりもキャラがある者の割合が多く, キャラがない者よりも自己有用感が高いことが示された。因子分析の結果, キャラの受け止め方は, "積極的受容", "拒否", "無関心", "消極的受容"の4つが得られた。得点とパス係数の比較を行った結果, 学校段階で違いが見られた。中学生では, 友人から付与されたキャラを受容しにくく, キャラに合わせて振る舞うことが, 心理的不適応と関連することが明らかになった。一方で, 大学生ではキャラ行動と適応には有意な関連が見られず, 付与されたキャラを消極的にでも受け容れることが, 居場所感の高さと関連していた。以上の結果から, 中学生におけるキャラを介した友人関係の危うさについて議論された。  Most contemporary adolescents communicate with their friends by using kyara, which is a shortened form of the Japanese pronunciation of the English word "character".  The purpose of the present study was to clarify relations between acceptance of kyara in friendship and psychological adjustment by comparing junior high and university students.  Junior high school students (n=396) and university students (n=244) completed a questionnaire.  The results suggested that the university students had a higher percentage than the junior high school students of use of kyara in friendship, and higher scores on sense of self-usefulness, compared to those who did not have a kyara.  Factor analysis identified 4 factors in acceptance of kyara: active acceptance, rejection, indifference, and passive acceptance.  The results of comparisons of scores and paths revealed differences correlated to educational level.  The junior high school students tended not to accept their kyara, and performing with their kyara was related negatively to psychological adjustment.  On the other hand, the university students\u27 performing with their kyara was not significantly related to any of the measures, and passive acceptance of kyara was related positively to the students\u27 sense of interpersonal rootedness