Comparison and characterization of α-amylase inducers in Aspergillus nidulans based on nuclear localization of AmyR

AmyR, a fungal transcriptional activator responsible for induction of amylolytic genes in Aspergillus nidulans, localizes to the nucleus in response to the physiological inducer isomaltose. Maltose, kojibiose, and d-glucose were also found to trigger the nuclear localization of GFP-AmyR. Isomaltose- and kojibiose-triggered nuclear localization was not inhibited by the glucosidase inhibitor, castanospermine, while maltose-triggered localization was inhibited. Thus, maltose itself does not appear to be an direct inducer, but its degraded or transglycosylated product does. Non-metabolizable d-glucose analogues were also able to trigger the nuclear localization, implying that these sugars, except maltose, directly function as the inducers of AmyR nuclear entry. The inducing activity of d-glucose was 4 orders-of-magnitude weaker compared with isomaltose. Although d-glucose has the ability to induce α-amylase production, this activity would generally be masked by CreA-dependent carbon catabolite repression. Significant induction of α-amylase by d-glucose was observed in creA-defective A. nidulans

Microbiological Investigation of the Iron-Containing Floculent Mats in Various Deep Sea Environments

Conference abstract (August 14-19, 2011, Goldschmidt 2011 in Prague, Czech Republic)http://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt10-13_leg2/ehttp://www.godac.jamstec.go.jp/darwin/cruise/yokosuka/yk10-10/

Multiple steady-states in a heat integrated distillation column (HIDiC)

A heat integrated distillation column (HIDiC) is a new and highly energy-efficient distillation process. In the present work, multiple steady-states in HIDiC are analyzed. In HIDiC, the pressure in the rectifying section is kept higher than that in the stripping section by using a compressor to enhance heat transfer from the rectifying section to the stripping section through the wall. Therefore, an energy balance, particularly the influence of the compressor, must be taken into account for the analysis. In this research, two types of operation policies are investigated: P1) constant compressor power and P2) constant pressure ratio. First, the conditions for making multiple steady-states are derived on the basis of the first principle model of the HIDiC. Then, the analysis results are validated through simulations. The results show that: 1) the instability condition depends largely on the compressor operation policies; 2) in case P1, multiple steady-states appear when the top product is highly pure, the bottom product is relatively impure, vapor flow rate is large, and compressor power is small; 3) in case P2, multiple steady-states appear when the bottom product is highly pure; and 4) multiple steady-states appear in a wider range of operation in case P2 than in case P1

Tarama Knoll: Geochemical and biological profiles of hydrothermal activity

Tarama Knoll is located about 60 km north of Tarama Island, Sakishima Islands, southwestern Japan. The knoll has an almost conical shape, with foot and summit depths of 2,000 and 1,490 m (total relief = 510 m) from the sea surface, respectively. This area has been identified as a possible active submerged volcano called “Tarama Knoll” (Otani et al. 2004). However, there are actually two separate knolls in the area. This knoll is located northeast of the other, which is named Tarama Hill. During the KT05-26 cruise on the R/V Tanseimaru, a methane anomaly was detected near the seafloor around the area and was considered to be of possible hydrothermal origin. Based on visual observation of the seafloor and its bathymetry, this knoll is considered a pumice cone. Dense turbid water is often observed around summit of the knoll, and a methane anomaly was detected in the water. These observations suggest that the turbid water is a hydrothermal plume. An iron-rich, red-brown sediment-covered area was discovered at a depth of 1,510–1,540 m on the southwestern slope near the summit. At the red-brown sediment area, a weak shimmering of clear fluid could be observed, and the fluid temperature reached 20 °C. Sampled shimmering fluid showed a high silica concentration (≥1 mM), indicating an interaction between the fluid and the surrounding rock. These chemical data support the occurrence of active hydrothermal circulation at Tarama Knoll

Concentrations and distributions of amino acids in black and white smoker fluids at temperatures over 200 °C.

http://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt12-14/