Copper, nickel, and cobalt entered into seawater solution while t,he manganese (IV) oxide matrix of marine ferromanganese nodules to which they were bound was being reduced by glucose in the presence of peptone. Negligible amounts of iron were solubilized under similar conditions. Bacillus G J 33 significantly accelerated the reduction and solubilization of manganese (IV) oxide by chemical means and thereby also accelerated the solubilization of nickel and cobalt, and, in advanced stages, of copper. Nickel and cobalt solubilization were directly dependent on manganese (IV) oxide reduction and solubilization while copper solubilization was only partly dependent on it. Some copper in the ferromanganese nodule substance was solubilized as a result of complexing by peptone without concurrent manganese (IV) oxide reduction. The release of manganese, copper, or nickel (cobalt was not tested) could not be attributed to acid formation during glucose oxidation by manganese (IV) oxide regardless of whether the reaction was purely chemical or catalyzed by bacteria. These findings suggest t h a t nickel and cobalt are more tightly bound to the manganese (IV) oxide matrix than copper. An adsorption experiment showed t h a t manganese, copper and nickel could originally have entered the nodule matrix by adsorption.Ferromanganese nodules on the surface of abyssal marine sediments have been reported to contain (in percent by weight): Mn 8 t o 50, Fe 2 to 27, Ni 0.2 to 2, Cu 0.03 to 2, and Co 0.01 to 2.3, as well as lesser amounts of some other metallic elements (MERO 1962). Most of the manganese and all of the iron occur in oxidized forms. According t o a widely quoted mineralogical description of ferromanganese nodule structure by BUSER and GRUETTER (1956), the manganese occurs in three forms, as recognized by X-ray diffraction. Listed in order of increasing states of oxidation, they are 10 A manganite, 7 A manganite, and 6 MnO,. The 6 MnO, was viewed as ordered sheets alternating with disordered layers of Mn2+ and Fe3+ ions coordinated with H,O, OH and 0. Manganese and iron in the disordered layers may be partly replaced by other cations according to these authors. Other independent studies have led to modifications of the model of mineralogical structure of mangenese nodules (see, for instance, KERL 1970, MANHEIM 1965). Distinct iron containing phases, like goethite and amorphous FeOOH, have been identified (KERL 1970). Cationic trace elements, like copper and nickel, are said to be predominantly associated with manganese and are pictured as being distributed in the manganite phase while Co is said to be incorporated into the lattice structure of the iron minerals (BURNS and FUERSTE-NAU 1966).

Although the general ultrastructure of Cyanidium caldarium, an acidophilic, thermophilic alga of questionable taxonomic rank, has been extensively studied (see review of literature in reference 1), some peculiar ultrastructural features of the chloroplast of this alga have not been noted by other investigators.Cells were collected and prepared for thin sections at the Yellowstone National Park and were also grown in laboratory cultures (45-52°C; pH 2-5). Fixation (glutaraldehyde-osmium), dehydration (ethanol), and embedding (Epon 812) were accomplished by standard methods. Replicas of frozenfracture d- etched cells were obtained in a Balzers apparatus. In addition, cells were examined after disruption in a French Press.

Copper, nickel, and cobalt entered into seawater solution while the manganese (IV) oxide matrix of marine ferromanganese nodules to which they were bound was being reduced by glucose in the presence of peptone. Negligible amounts of iron were solubilized under similar conditions. Bacillus GJ 33 significantly accelerated the reduction and solubilization of manganese (IV) oxide by chemical means and thereby also accelerated the solubilization of nickel and cobalt, and, in advanced stages, of copper. Nickel and cobalt solubilization were directly dependent on manganese (IV) oxide reduction and solubilization while copper solubilization was only partly dependent on it. Some copper in the ferromanganese nodule substance was solubilized as a result of complexing by peptone without concurrent manganese (IV) oxide reduction. The release of manganese, copper, or nickel (cobalt was not tested) could not be attributed to acid formation during glucose oxidation by manganese (IV) oxide regardless of whether the reaction was purely chemical or catalyzed by bacteria. These findings suggest that nickel and cobalt are more tightly bound to the manganese (IV) oxide matrix than copper. An adsorption experiment showed that manganese, copper and nickel could originally have entered the nodule matrix by adsorption.