Colonization and Decomposition of Fish Bone Material in Natural and Synthetic Aqueous Solutions

Abstract

Partial dissolution of the inorganic (apatite) fraction of flesh-free fish (Perca sp.) cheek-bone material, added to P-free (−1 total P) nutrient media as bone chips with a particle-size distribution of −1). Bacteria and algae rapidly colonized the apatitic bone material and produced extracellular material in response to growth on bone surfaces. Acidic filtrates from bacterial cultures, aerobically or anaerobically cultivated in apatite media, readily solubilized bone material as indicated by increases in soluble ortho-PO₄³⁻ concentrations after short exposure periods. Water extraction of bone apatite crystals showed that fish bones are sparingly soluble in lake water. Microbially mediated dissolution of bone material by acid end-products of bacterial metabolism would therefore greatly increase the rate of bone dissolution in nature. Regeneration of allochthonous-P from fish-bone dissolution may contribute significantly to the P-cycle of many aquatic ecosystems. Key words: biologic apatite, calcium phosphate, fish bone carbonate hydroxyapatite, dahllite