peroxisomal matrix (GO:0005782)

The volume contained within the membranes of a peroxisome in many cells the matrix contains a crystalloid core largely composed of urate oxidase.

Specific

glycosome lumen (GO:0034468) glyoxysomal lumen (GO:0031908)

General

peroxisomal part (GO:0044439) microbody lumen (GO:0031907)

References

gene ontology: GO:0005782