Fig. 6

Schematic illustration of bone digestion and nutrient uptake in Osedax japonicus. Calcium phosphate in vertebrate bone is digested through acidification of the microenvironment by V-H⁺-ATPase [24]. Organic components of bones, such as collagens are degraded by proteases secreted from root epidermis. The digested peptides and other nutrients contained in the bones are transported through various membrane transporters. Some of the nutrients are transported to symbiotic bacteria, which use the nutrients as a metabolic resource