Deciphering a Marine Bone-Degrading Microbiome Reveals a Complex Community Effort

Area of Science:

• Marine microbiology and metagenomics
• Biogeochemical cycling and enzymatic degradation
• Biotechnological applications of biopolymers

Background:

• The marine bone biome's enzymatic capabilities for nutrient acquisition are largely unknown.
• Bone is a composite of collagen and hydroxyapatite, requiring diverse enzymatic and chemical processes for degradation.
• Understanding bone degradation is crucial for utilizing meat industry byproducts.

Purpose of the Study:

• To investigate the microbial enzymatic repertoire involved in marine bone degradation.
• To identify microbial taxa and genes responsible for breaking down organic bone components.
• To explore the potential of marine bone-derived resources for biotechnology.

Main Methods:

• Field experiments involving the deposition of bovine and turkey bones in a Norwegian fjord.
• Metagenomic sequencing and analysis of microbial communities on bone surfaces and associated with *Osedax mucofloris*.
• Bioinformatic analysis to identify functional genes and enzymatic pathways, including the reconstruction of metagenome-assembled genomes (MAGs).

Main Results:

• A diverse bone microbiome was revealed, with 59 high-quality MAGs from at least 23 bacterial families.
• Over 700 genes encoding collagenases, peptidases, and glycosidases, crucial for bone degradation, were identified.
• A novel, large collagen utilization gene cluster was discovered in the *Colwellia* genus, and a sulfur cycle mechanism was proposed for demineralization.

Conclusions:

• Marine microbial communities possess a rich enzymatic toolkit for degrading bone matrix components.
• The interplay between diverse bacterial taxa, including sulfur-cycling bacteria and collagen-degrading specialists like *Colwellia*, is essential for bone breakdown.
• Identified microbial pathways and genes offer potential for biotechnological applications in processing bone residues.