ROLE OF THE BIOGENIC FACTOR IN THE GENERATION OF PELAGIC IRON-MANGANESE NODULES

Abstract

In microbiological generation, bacteria can play a dual role: producing a catalytic effect that promotes the oxidation of manganese and thus converts it to insoluble form (heterotrophic bacteria), or accumulating iron in their cells (specific bacteria). From this viewpoint it is interesting to consider the dynamic interaction between living and nonliving matter in the generation of nodules, an investigation which has never yet been undertaken. The present article is the first attempt to do so. Interpreting the results, we draw the following preliminary conclusions. The regular correlation of phosphorus with manganese and iron in the growth of nodules over their entire lifetime indicates that phosphorus, and thus a diverse microflora, plays an important role in the development of natural pelagic nodules. The manganese fraction correlated with phosphorus and in phase with it probably was deposited by organisms inhabiting the nodules. From all the evidence, the phosphate-depositing bacteria must be an essential component of these biocoenoses. This deposition process has been confirmed experimentally. Numerous bacterial structures have been found in the phosphates of various deposits; in many cases they are closely associated with iron bacteria.