Amorphous nanoparticles in clays, soils and marine sediments analyzed with a small angle X-ray scattering (SAXS) method.

This paper describes the amounts and size distributions of amorphous nanoparticles in clays, soils and marine sediments, and the effect of amorphous nanoparticles on the properties of clays, soils and marine sediments. So far aluminum-silicate amorphous nanoparticles such as allophane were observed only in soils of volcanic origin with a transmission electron microscope, and thus most people believed that aluminum-silicate amorphous nanoparticles were present only in soils of special origin. Recently, a method has been devised to quantify amorphous nanoparticles by using small angle X-ray scattering intensity.

Defining boundaries for the distribution of microbial communities beneath the sediment-buried, hydrothermally active seafloor.

Subseafloor microbes beneath active hydrothermal vents are thought to live near the upper temperature limit for life on Earth. We drilled and cored the Iheya North hydrothermal field in the Mid-Okinawa Trough, and examined the phylogenetic compositions and the products of metabolic functions of sub-vent microbial communities. We detected microbial cells, metabolic activities and molecular signatures only in the shallow sediments down to 15.

First cultivation and ecological investigation of a bacterium affiliated with the candidate phylum OP5 from hot springs.

The phylogenetic group termed OP5 was originally discovered in the Yellowstone National Park hot spring and proposed as an uncultured phylum; the group was afterwards analyzed by applying culture-independent approaches. Recently, a novel thermophilic chemoheterotrophic filamentous bacterium was obtained from a hot spring in Japan that was enriched through various isolation procedures. Phylogenetic analyses of the isolate have revealed that it is closely related to the OP5 phylum that has mainly been constructed with the environmental clones retrieved from thermophilic and mesophilic anaerobic environments.