Extending outwards from the core are the mantle and the crust. Earth's mantle extends to a depth of 2,890 km beneath the surface, making it the thickest layer of Earth. This layer is composed of silicate rocks that are rich in iron and magnesium relative to the overlying crust.
The Parasite: Balantidium coli. Balantidium coli is the only ciliate known to parasitize humans. Ciliates represent a phylum of protozoa characterized, in at least one stage of development, by simple or compound ciliary organelles on the surface of their membranes that are used for locomotion.
2-Mercaptobenzothiazole, which is mainly used in the rubber industry as a vulcanization accelerator, is very toxic and is considered to be recalcitrant. We show here for the first time that it can be biotransformed and partially mineralized by a pure-culture bacterial strain of Rhodococcus rhodochrous. Three metabolites, among four detected, were identified. 2-Mercaptobenzothiazole (MBT) is the most important and most widely used member of the benzothiazole (BT) family. MBT is typically a rubber additive, but it has also other applications, such as inhibiting biocorrosion in cooling systems or in paper manufacturing.