Japan Agency for Marine-earth Science and Technology

The University of Tokyo

Ken Takai

Ikuo Sawada

Tomokazu Saruhashi

Junichi Miyazaki

Takazo Shibuya

Kentaro Nakamura

Kazuhito Hashimoto

Koki Horikoshi

Ryuhei Nakamura

Yuji Hatada

Susumu Ito

Junichiro Ishibashi

Si Hung Vo

Zhi Jun Li

Jie Lu

Katsuhiko Suzuki

Teruhiko Kashiwabara

Tatsuo Nozaki

Shinsuke Kawaguchi

Masahiro Yamamoto

A power generation system includes a hydrothermal fluid well including a drilled hole reaching down to a hydrothermal fluid reservoir present below an ocean floor from an ocean floor surface and a casing installed in the drilled hole through a guide base on the ocean floor surface, an anode provided on a flow channel for hot water formed by the hydrothermal fluid well, a cathode provided in seawater other than the flow channel for hot water formed by the hydrothermal fluid well, and an ocean floor device that is connected with the anode and the cathode respectively and extracts generated power so as to operate. Power is easily and stably supplied on the ocean floor.

Power generation system

A recovery method for recovering mineral resources from a hydrothermal fluid reservoir present beneath the ocean floor includes the steps of: (A) providing a hydrothermal fluid well by drilling a hole reaching a hydrothermal fluid reservoir from an ocean floor surface via a guide base on the ocean floor surface, and then installing a casing in the drilled hole via the guide base; (B) precipitating minerals on a mineral-culturing device by installing the mineral-culturing device on the base guide so as to cover a well head of the hydrothermal fluid well, and bringing hot water ejecting from the well head into contact with sea water on the mineral-culturing device; and (C) recovering minerals precipitated on the mineral-culturing device together with the mineral-culturing device.

Method and system for recovering ocean floor hydrothermal mineral resources

The invention aims to provide a novel alkaline protease having peculiar properties such as high alkali activity, resistance to surfactants and calcium-dependent thermostability and exhibiting excellent performance in highly alkaline detergents, and a gene coding for the amino acid sequence thereof. There is provided an alkaline protease with such properties that an active pH range is from 5 to 13, an optimum pH is approximately 12.6, an optimum temperature is 70&#xb0; C., no activity drop by heating is observed up to 65&#xb0; C. at pH 10 and the optimum temperature and the thermostability are not affected by Caions. Specifically, there is provided, for example, an alkaline protease having an amino acid sequence constituting a mature enzyme as represented by SEQ ID NO: 3 or an amino acid sequence resulting from deletion, substitution, situs inversus arrangement, addition or insertion of a part of amino acids thereof, or derived from The protease cleaves 26 peptide bonds among 29 peptide bonds of acidic insulin B-chain.

High alkaline protease and use thereof

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Yokosuka, Japan

Ken Takai