857 research outputs found

    Wild otter observation on Gurney Drive coast in Penang Island, Malaysia

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    Otter was irregularly observed on Gurney Drive coast in the northern part of Georgetown, Penang Island from June 2015 to March 2016. Authors examined relationship between the otters sighting date and time and the tide pattern. Otter was observed a total of five times on 27th June, 17th August, 6th December 2015, 14th March, and 16th March 2016. These otters were identified same species which was the smooth-coated otter, Lutrogale perspicillata, from the morphological characteristics. Swimming direction of the otters were characterized two patterns that the first was the otters swam from inner part to east coast in a cove of Gurney Drive coast and the second was the otters swam from the east coast to inner part of the cove. From this result, it was suggested that the otters swam to drive fish toward tide flow and the otters catch the fish efficiently

    Yeast methylotrophy: metabolism, gene regulation and peroxisome homeostasis.

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    Eukaryotic methylotrophs, which are able to obtain all the carbon and energy needed for growth from methanol, are restricted to a limited number of yeast species. When these yeasts are grown on methanol as the sole carbon and energy source, the enzymes involved in methanol metabolism are strongly induced, and the membrane-bound organelles, peroxisomes, which contain key enzymes of methanol metabolism, proliferate massively. These features have made methylotrophic yeasts attractive hosts for the production of heterologous proteins and useful model organisms for the study of peroxisome biogenesis and degradation. In this paper, we describe recent insights into the molecular basis of yeast methylotrophy

    Methylovulum miyakonense gen. nov., sp. nov., a type I methanotroph isolated from forest soil.

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    A novel methanotroph, designated strain HT12(T), was isolated from forest soil in Japan. Cells of strain HT12(T) were Gram-reaction-negative, aerobic, non-motile, coccoid and formed pale-brown colonies. The strain grew only with methane and methanol as sole carbon and energy sources. Cells grew at 5-34 °C (optimum 24-32 °C). The strain possessed both particulate and soluble methane monooxygenases and assimilated formaldehyde using the ribulose monophosphate pathway. The major cellular fatty acids were C(16 : 0) (46.9 %) and C(14 : 0) (34.2 %), whereas unsaturated C(16) fatty acids, typical of type I methanotrophs, were absent. Comparative 16S rRNA gene sequence analysis showed that the most closely related strains were Methylosoma difficile LC 2(T) (93.1 % sequence similarity) and Methylobacter tundripaludum SV96(T) (92.6 % similarity). Phylogenetic analysis based on the pmoA gene indicated that strain HT12(T) formed a distinct lineage within the type I methanotrophs and analysis of the deduced pmoA amino acid sequence of strain HT12(T) showed that it had a 7 % divergence from that of its most closely related species. The DNA G+C content was 49.3 mol%. Based on this evidence, strain HT12(T) represents a novel species and genus of the family Methylococcaceae, for which the name Methylovulum miyakonense gen. nov., sp. nov. is proposed. The type strain of the type species is HT12(T) ( = NBRC 106162(T)  = DSM 23269(T)  = ATCC BAA-2070(T))

    Digestive tube contents of blood cockle (Anadara granosa) in a tropical mangrove estuary in Malaysia

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    This study was carried out to clarify the feeding biology of the blood cockle (Anadara granosa). We collected blood cockles from 8 stations in the Matang mangrove estuary of Malaysia in July and August 2010. The digestive tube contents of the specimens were stained with Congo red and observed under a light microscope. The results showed blood cockles take in particles containing cellulose as well as phytoplankton such as diatoms. As blood cockles in estuaries are known to exhibit cellulolytic enzyme activity in their digestive gland, the present results indicate blood cockles in estuaries feed on litter supplied from mangrove forests and terrestrial plants

    Sexual maturation of the blood cockle, Anadara granosa, in Matang mangrove estuary, peninsular Malaysia

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    The sexual maturation and spawning period of blood cockle in Matang mangrove estuary was studied by naked eye and histological observations of the gonads from July 2010 to April 2011. The high spawning period was from November to February. However, at one station where bottom sediment exhibited a severe reduction in potential of −100 mV lower, immature individuals were common. These results suggest the redacting environment inhibits the sexual maturation of blood cockle

    Ion microprobe mesearments of Mg isotopes in Type B1 CAI of Allende meteorite

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    Magnesium isotopes in individual mineral grains of a Ca-Al rich inclusion from the Allende meteorite have been measured by secondary ion mass spectrometry. An electrostatic peak switching system was used to make a precise isotopic measurement in high mass resolution mode (M/⊿M=∿4000). The inclusion shows excess of ^Mg correlated with the ^Al/^Mg ratio. The results suggest that live ^Al decayed in the inclusion which formed simultaneously in the solar nebula. The relative abundance of ^Al(^Al/^Al=3.12×10^) is close to the "canonical" value (^Al/^Al=∿5×10^) for coarse-grained CAIs

    Stress resistance and C1 metabolism involved in plant colonization of a methanotroph Methylosinus sp. B4S.

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    Methanotrophs are widespread and have been isolated from various environments including the phyllosphere. In this study, we characterized the plant colonization by Methylosinus sp. B4S, an α-proteobacterial methanotroph isolated from plant leaf. The gfp-tagged Methylosinus sp. B4S cells were observed to colonize Arabidopsis leaf surfaces by forming aggregates. We cloned and sequenced the general stress response genes, phyR, nepR and ecfG, from Methylosinus sp. B4S. In vitro analysis showed that the phyR expression level was increased after heat shock challenge, and phyR was shown to be involved in resistance to heat shock and UV light. In the phyllospheric condition, the gene expression level of phyR as well as mmoX and mxaF was found to be relatively high, compared with methane-grown liquid cultures. The phyR-deletion strain as well as the wild-type strain inoculated on Arabidopsis leaves proliferated at the initial phase and then gradually decreased during plant colonization. These results have shed light firstly on the importance of general stress resistance and C1 metabolism in methanotroph living in the phyllosphere

    Unique C-terminal region of Hap3 is required for methanol-regulated gene expression in the methylotrophic yeast Candida boidinii

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    The Hap complex of the methylotrophic yeast Candida boidinii was found to be required for methanol-regulated gene expression. In this study, we performed functional characterization of CbHap3p, one of the Hap complex components in C. boidinii. Sequence alignment of Hap3 proteins revealed the presence of a unique extended C-terminal region, which is not present in Hap3p from Saccharomyces cerevisiae (ScHap3p), but is found in Hap3p proteins of methylotrophic yeasts. Deletion of the C-terminal region of CbHap3p (Δ256–292 or Δ107–237) diminished activation of methanol-regulated genes and abolished the ability to grow on methanol, but did not affect nuclear localization or DNA-binding ability. However, deletion of the N-terminal region of CbHap3p (Δ1–20) led to not only a growth defect on methanol and a decreased level of methanol-regulated gene expression, but also impaired nuclear localization and binding to methanol-regulated gene promoters. We also revealed that CbHap3p could complement the growth defect of the Schap3Δ strain on glycerol, although ScHap3p could not complement the growth defect of a Cbhap3Δ strain on methanol. We conclude that the unique C-terminal region of CbHap3p contributes to maximum activation of methanol-regulated genes, whilst the N-terminal region is required for nuclear localization and binding to DNA

    Water in Earth's mantle: Hydrogen analysis of mantle olivine, pyroxenes and garnet using the SIMS

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    Hydrogen (or water) in the Earth's interior plays a key role in the evolution and dynamics of the planet. However, the abundance and the existence form of the hydrogen have scarcely been clear in practice. Hydrogen in the mantle was incorporated in the interior during the formation of the Earth. The incorporated hydrogen was hardly possible to concentrate locally inside the Earth considering its high mobility and high reactivity. The hydrogen, preferably, could be distributed homogeneously over the mantle and the core by the subsequent physical and chemical processes. Therefore, hydrogen in the mantle could be present in the form of trace hydrogen in nominally anhydrous mantle minerals. The hydrogen and the other trace elements in mantle olivines, orthopyroxenes, clinopyroxenes, and garnets were determined using secondary ion mass spectrometry (SIMS) for elucidating (1) the exact hydrogen contents, (2) the correlation between the hydrogen and the other trace elements, (3) the dependence of the hydrogen contents on the depth, and (4) the dependence of the whole rock water contents on the depth

    H2O contents and hydrogen isotopic composition of apatite crystals from L, LL5-6 ordinary chondrites.

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    第3回極域科学シンポジウム/第35回南極隕石シンポジウム 11月30日(金) 国立国語研究所 2階講
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