ABSTRACT
Biological mineralization occurs in many crystalline forms and in organisms as diverse as bacteria and man. While the major thrust of this work is to discuss bacterial mineralization, and, more specifically, bacterial calcification, some digressions to, and comparisons with organisms will be made. When and why mineralization of unicellular organisms first appeared is a question to which speculation is the only answer. Originally, the various forms of mineralization may have occurred in order to ensure survival of the organism in a chemically hostile environment. The planktonic Foraminifera are a major source of oceanic calcium carbonate and can be broadly classified into two taxonomic divisions, the spinose and nonspinose, which differ as to the degree of mineralization. The formation of hydroxyapatite is governed by stringent physicochemical requirements. Initial mineralization in bone, dentin and ectopic pathological calcifications, appears to involve similar mechanisms.
