Microbial bioerosion of bone – a review

Microbial alteration is an important pathway for bone degradation. Organisms involved in bioerosion of bone, mainly bacteria, fungi and cyanobacteria, create different types of alteration. While fungi and cyanobacteria dissolve the bone matrix resulting in branching tunnels, bacteria create microscopical focal destructions with a complex morphology, reorganising the mineral rather than removing it. Different environmental and early post mortem circumstances characterise each type. Bacterial alteration occurs in the early post mortem interval, probably in the first decades after death. A strong link with putrefaction can be observed, indicating that early putrefactive organisms are important contributors to bacterial alteration of bone. Fungal and cyanobacterial alteration occurs when the environment is favourable, i.e., oxygen is present and bone still has sufficient nutrient value. Although microbial alteration causes loss of information in archaeological and palaeontological bone, the study of microbial bioerosion also represents a powerful tool for taphonomic reconstruction.